In recent decades, perovskite-type compounds (ABB′O3) have been exhaustively studied due to their unique ferroelectric properties. In this work, a systematic study aiming to prepare fine particles in the binary system SrZrO₃–SrTiO₃ was conducted under hydrothermal conditions in a KOH (5 M) solution at 200 °C for 4 h under a constant stirring speed of 130 rpm. The precursors employed were SrSO₄ powder (< 38 μm size) and coprecipitated hydrous gels of Zr(OH)₄•9.64 H₂O (Zr-gel) and Ti(OH)₄•4.5H₂O (Ti-gel), which were mixed according to the stoichiometry of the SrZr_1-xTixO₃ in the compositional range of 0.0>x>100.0 mol% Ti⁴⁺. The XRD results revealed the formation of two crystalline phases rich in Zr⁴⁺, an orthorhombic structured SrZr0.93Ti0.07O3 and a cubic structured SrZr0.75Ti0.25O3 within the compositional range of 0.1–0.5 mol of Ti4+. A cubic perovskite-structured solid solution, SrTi1-xZrxO3, was preferentially formed within the compositional range of 0.5>x>0.1 mol% Ti⁴⁺. The SrZrO₃ and SrZr_0.93Ti_0.07O₃-rich phases had particle sizes averaging 3 m with a cubic morphology. However, a remarkable reduction in the particle size occurred on solid solutions prepared with hydrous Ti-gel over contents of 15 mol% Ti⁴⁺ in the reaction media, resulting in the formation of nanosized particles agglomerates with cuboidal shape self-assembled via a 3D hierarchical architecture, the sizes of these particles varied in the range between 141.0–175.5 nm. The limited coarsening of the particles is discussed based on the Zr-gel and Ti-gel dehydration capability differences that occurred under hydrothermal processing.

Hydrothermal /super critical processes are important process to synthesize materials which are otherwise difficult to form under normal conditions. A mathematical model is developed using standard transport equations to calculate the time for heating of hydrothermal reactor and computer simulation of the model was carried out in SOLIDWORKS® to validate it. The materials used to form reactor vessel were stainless steel (outer body) and TEFLON (PFA) (inner vessel). It was shown that composite wall, its geometry, construction & properties greatly affect the time and pattern of heat transfer. The time calculated and pattern generated were found to be in good agreement with experimental values.

In this work, the effect of reaction time and biomass-to-H2O ratio on the structural evolution of hydro-char and kinetic of by hydrothermal processing of corn Stover with hot compressed H2O, have been systematically investigated. The experiments were carried out at 250 °C, heating rate of 2.0 °C/min, biomass-to-H2O ratio of 1:10, and reaction times of 60, 120, and 240 minutes, and at 250 °C, 240 minutes, heating rate of 2.0 °C/min, and biomass-to-H2O water ratio of 1:10, 1:15, and 1:20, using a pilot scale stirred tank reactor of 5 gallon. The characterization of solid phase products performed by thermo-gravimetric analysis, scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, and elemental analysis (C, N, H, S). The physical-chemistry properties of solid phase analyzed in terms of dry matter (DM), total organic content (TOC), and ash. The yields of solid and gas phases decrease linearly with decreasing biomass-to-H2O ratio, while that of liquid phases increases linearly. For constant biomass-to-H2O ratio, the yields of solid, liquid, and gaseous reaction products varied between 52.97 and 35.82% (wt.), 44.84 and 54.59% (wt.), and 2.19 and 9.58% (wt.), respectively. The yield of solids decreases exponentially by decreasing the reaction time, while the yields of liquid and gas phases increase exponentially. For constant biomass-to-H2O ratio, TG/DTG curves shows that reaction time of 60 minutes was not enough to carbonize corn Stover. For constant reaction time, TG/DTG curves shows that increasing the H2O-to-biomass ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the SEM images show the main morphological structure of the corn Stover remains practically unchanged, while for constant reaction time, SEM images show that plant microstructure retains part of its original morphology, demonstrating that a decrease on biomass-to-H2O ratio worse the carbonization of corn Stover. For constant biomass-to-H2O ratio, the EDX analysis shows that the carbon content in hydro-char increases with reaction time, while for constant reaction time, the carbon content decreases with increasing biomass-to-H2O ratio. The kinetic of corn Stover degradation was correlated with a pseudo-first order exponential model, exhibiting a root-mean-square error (r2) of 1.000, demonstrating that degradation kinetics of corn Stover with hot compressed H2O, expressed as hydro-char formation, is well described by an exponential decay kinetics.

Zn2GeO4 is considered a very promising alternative to current luminescent semiconductors. Previous results suggest that its emitted wavelength may depend on different variables, such as particle size and morphology, among others. In this work, we have prepared pure and highly homogeneous Zn2GeO4 nanorods under hydrothermal synthesis conditions with a willemite-like structure. Their luminescent properties have been explored and their band gap estimated, which are distinct to previously reported Zn2GeO4 bulk particles. Therefore, our results identify particle morphology as a crucial factor for maximizing and fine-tuning the luminesce of Zn2GeO4 nano-phosphors.

Abiogenic hydrocarbons are fundamentally important for understanding the deep microbial communities and the origin of life. The generation of abiogenic hydrocarbons was proposed to be limited to ultramafic-hosted hydrothermal systems, fueled by the serpentinization product H₂. Here, we present the discharge of short-chain alkanes from an andesitic rock-hosted Lutao geothermal field in the north Luzon arc, carrying abiotic chemical and isotopic signals. These abiogenic hydrocarbons were generated from CO₂-H₂O-rich fluid inclusions, where the long-term storage since Lutao volcanism (~ 1.3 Ma) allowed overcoming the sluggish kinetics of CO₂ to CH₄ reduction at temperatures of 174 - 206 ^oC. Natural abiogenic production of hydrocarbons, therefore, can be more ubiquitous than previously thought. The hypothesis regarding the origin of methane in Earth’s early atmosphere and its implication to the origin of life may require reconsideration.

Owing to its properties, boron carbide has been applied in scientific and industrial fields. For this reason, B4C powders should be characterized by high purity and homogeneity in grain size and shape. In this study, boron carbide was prepared using precursors obtained by a hydrothermal method, and the grain morphology of the product was investigated. Boric acid and the saccharides glucose, fructose, inulin, and sorbitol were used as the precursors. Two precursor dehydration methods, freeze-drying and recrystallization, were compared. The precursors were subjected to DLS grain size and FT-IR spectrophotometric studies, and SEM observations of the precursors and products were performed, confirming that boron carbide powders with submicron spherical grains could be successfully synthesized.

This research investigates the difference on the products obtained through two hydrothermal carbonization treatments. Our aim is to synthesize metal-free, carbon-based catalysts for the Oxygen Reduction Reaction (ORR) to serve as efficient and cost-effective alternatives to plati-num-based catalysts. Catalysts synthesized using the traditional hydrothermal approach exhibit a higher electrocatalytic activity for ORR in alkaline media, despite a more energy-intensive pro-duction process. The superior performance is attributed to differences in particle morphology and to the chemical composition of the particle surfaces. The presence of functional groups on the surfaces of catalysts obtained via traditional approach significantly enhances ORR activity by fa-cilitating deprotonation reactions in an alkaline environment. Our research aims to be a reference for future investigations, shifting the focus to the fine-tuning of surface chemical compositions and morphologies of metal-free catalysts to enhance ORR activity.

The control of alumina morphology is crucial yet challenging for its various applications. Un-fortunately, traditional methods for preparing alumina particles suffer from several limitations such as irregular morphology, poor dispersibility, and restricted application areas. In this study, we develop a novel method for preparing spherical mesoporous alumina using chitin and Plu-ronic P123 as mixed templates. The effects of reaction temperature, time, and the addition of mixed templates on the phase structure, micromorphology, and optical absorption properties of the samples were investigated. The experimental results indicate that lower temperature and shorter reaction time facilitated the formation of spherical mesoporous alumina with excellent CO2 adsorption capacity. The periodic density functional theory (DFT) calculations demonstrate that both (110) and (100) surfaces of γ-Al2O3 can strongly adsorb CO2. The difference in the amount of CO2 adsorbed by Al2O3 is mainly due to the different surface areas, which give dif-ferent number of exposed active sites. This approach introduces a novel strategy for utilizing bi-ological compounds to synthesize spherical alumina and greatly enhances mesoporous alu-mina's application efficiency in adsorption fields. Moreover, the study explored the electro-chemical performance of the synthesized product using cyclic voltammetry and discovered im-proved loading of electrocatalysts and enhanced electrocatalytic activity.

Ni1-xGdxFe2O4 (x=0.02, 0.04, 0.06 & 0.08) (NGF) nanoparticles were synthesized via hydrothermal method. The X-ray diffraction study confirmed the single-phase cubic spinel structure. The morphology indicated the stones (approximately nanocubes) like structures in the FESEM images. The mass loss, and thermal transition temperatures were evaluated as a function of Gd-content using TG-DTG, and TG-DSC measurements. The M-H loops evidenced the high magnetization values for NGFO as compared to pure nickel ferrite. Cation distribution showed the preferred occupancy of cations in the magnetic spinel system. Frequency dependence of dielectric, conductivity, and impedance parameters was elucidated with increase in Gd-content.

Relationship between caveman prehistoric life in terms of heat induced food processing and its geological ecosystems have received many attentions. Previous studies have investigated the sources of heat included using Fourier transform infrared spectroscopy and biomarker approaches. Here this study proposes the use of remote sensing to identify the relationship of 9500 year old (9.5 ka) prehistoric mongoloid occupancy with hydrothermal manifestations at Pawon cave of West Java. The hydrothermal manifestations around Pawon cave were identified using Landsat 8 band combinations, land surface temperature, and sedimentary lithology. The results showed the hydrothermal manifestations surrounding Pawon cave were within a distance of 0.5-2 km. The results also showed bones representing 12 animal taxon groups with high abundance of rodents. To conclude this study sheds the light of proximity and preferences of mongoloid prehistoric occupancy towards hydrothermal landscape due to its advantage as heat sources for food processing purposes.

The use of low-cost, Remotely Operated Vehicle (ROV) and underwater photogrammetry techniques for 3D reconstruction of shallow hydrothermal vent sites around Paleochori Bay, Milos Island, Greece. Characterising venting fields through interactive bathymetry models produced from still images taken from camera onboard ROV flown over areas of interest in double raster pattern. First time the shallow venting fields on Milos have been actively surveyed using ROV. Areas were successfully surveyed and the bathymetry was reconstructed using SfM photogrammetry with a ~10 cm scale resolution. A diverse range of benthic habitats were surveyed and the resulting topographic models will act as a baseline, providing further characterisation of the vent systems and any evolving seafloor morphology associated with mineral deposition.

Serpentine (Mg₃Si₂O₅(OH)₄), like quartz, dolomite and magnesite minerals, is a versatile mineral group characterized by silica and magnesium silicate contents with multiple polymorphic phases. Among the phases composed of antigorite, lizardite, and chrysotile, lizardite and chrysotile are the most prevalent phases in the serpentinites studied here. The ΣLREE/ΣHREE ratios of the samples are between 0.16 and 4 ppm. While Ce shows a strong negative anomaly (0.1–12), Eu shows a weak positive anomaly (0.1–0.3). This indicates that fluid interacts significantly with rock during serpentinization, and Highly Incompatible Elements (HIEs) gradually become involved in the serpentinization process. The large differential thermal analysis (DTA) peak at 810–830 °C is an important sign of dehydration, transformation reactions and thermal decomposition, and is com-patible with H₂O phyllosilicates in the mineral structure losing water at this temperature. In SEM images, chrysotile, which has a fibrous structure, and lizardite, which has a flat appearance, trans-form into talc as a result of dehydration with increasing temperature. Therefore, the sudden tem-perature drop observed in DTA graphs is an indicator of crystal form transformation and CO₂ loss. In this study, the mineralogical and structural properties and the formation of serpentinites were examined for the first time using thermo-gravimetric analysis methods. In addition, the mineralogical and physical properties of serpentinites can be recommended for industrial use as additives in polymers or in the adsorption of organic pollutants. As a result, the high refractory nature of examined serpentine suggests that it is well-suited for applications involving high temperatures. This includes industries such as metallurgy and steel production, glass manufacturing, ceramic production, and the chemical industry.

The generation of platform chemicals and hydrochar is of great interest because they reduce dependence on fossil resources and contribute to climate change mitigation by reducing carbon emissions. The main objective of this study was to evaluate the effect of biomass particle size and biomass water ratio in a hydrothermal conversion system for the generation of value-added products obtained from sugarcane bagasse. Biomass characterization was performed using proximal, elemental, and structural analysis; hydrothermal carbonization was carried out at 220 to 260 °C for one hour; and conversion was monitored using pH, conductivity, and IR spectroscopy. Platform chemicals were quantified by HPLC-IR. Hydrochars were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that with a biomass:water ratio of 1:50 and a particle size of 212 μm at 220 °C, a yield of 31.07 % of platform chemicals was obtained on a dry basis. Likewise, the hydrochar with the highest carbon content and a higher porosity appearance was obtained with a biomass-to-water ratio of 1:50 and a particle size of 600 μm at 260 °C.

Quarry waste fines and eggshells are unavoidable wastes which relentlessly contribute to environmental load and pollution. Although a number of studies have suggested various methods for recycling, these wastes remain underutilized due to some technical constraints. In addition, no study has yet been explored on the possibility of combining quarry waste fines (QWF) and eggshell powder (ESP) for tobermorite synthesis. Tobermorite is the main component which primarily provides strength to the autoclaved aerated concrete products. For this purpose, this study seeks to evaluate the potential of QWF- ESP mix at 10%, 15% and 20% amounts of cement, respectively. The XRF, XRD, and TGA–DTA techniques were used to characterize the waste materials while physical and mechanical property tests and XRD analysis were performed on the autoclaved samples. It was found that QWF contains 53.77% SiO2, while ESP contains 97.8% CaO which are key components for tobermorite synthesis. This study also revealed that the mixture with only 10% cement has the highest compressive strength among the QWF-ESP samples. Furthermore, the formation of tobermorite in the samples was confirmed through XRD analysis. Hence, the hydrothermal curing of QWF –ESP can be further developed to produce functional tobermorite – bearing materials.

Adopting banana peel as raw material, the adsorption properties of banana peel hydrothermal carbon modified with KOH solution for lead ions in aqueous solution were studied. The surface structure and functional groups of the modified hydrothermal carbon were analyzed by XRD and SEM. The results showed that the banana peel hydrothermal carbon prepared from 0.5 mol/L KOH solution had large pores, and its adsorption capacity reached 42.92 mg/g at a pH value of 6; When the concentration of KOH solution is 0.5 mol/L, the solid liquid ratio is 2 g/L, the adsorption capacity reaches 21.39 mg/g, and the adsorption rate reaches 82.74%; When the concentration of lead solution increased to 100 mg/L, the adsorption capacity of modified hydrothermal carbon for lead ions decreased to 78.26%; The equilibrium adsorption time of lead ion in solution on phosphoric acid modified hydrothermal carbon from banana peel was 250 minutes, and the adsorption process met the quasi second order kinetic model and Freundlich isotherm equation, with an equilibrium adsorption rate of 88.62%. The adsorption of lead ions in solution by KOH modified hydrothermal carbon is mainly chemical physical adsorption.

Using banana peel as raw material, the adsorption properties of hydrothermal carbon pre-10 pared from banana peel modified with different concentrations of phosphoric acid solution for lead 11 ions in aqueous solution were studied. The surface structure and functional groups of the modified 12 hydrothermal carbon were analyzed by XRD and SEM. The results show that the surface of the 13 modified banana peel hydrothermal carbon prepared at 240℃ and 2mol/L phosphoric acid solution 14 has large pores. The adsorption capacity is larger when pH value is 6.When the concentration of 15 phosphoric acid solution was 2mol/L, the solid-liquid ratio was 2g/L, the adsorption capacity was 16 40.64mg/g, and the removal rate was 82.74%.When the initial concentration of lead solution in-17 creased to 100mg/L, the adsorption capacity of modified hydrothermal carbon for lead ion increased 18 to 76.81mg/g, and the removal rate decreased to 76.81%.The equilibrium adsorption time of banana 19 peel phosphoric acid modified hydrothermal carbon for lead ions in solution is 300min. The adsorp-20 tion process satisfies the pseudo-second-order kinetic model and Langmuir isotherm equation. The 21 reaction temperature is 313K, and the equilibrium adsorption capacity can reach 101.19mg/g. The 22 adsorption of Pb ions in aqueous solution by phosphoric acid modified hydrothermal carbon is 23 dominated by single layer chemisorption. The artificial neural network has a fitting correlation of 24 0.99, and the adsorption process includes physical adsorption, electrostatic attraction, ion exchange, 25 and surface complexation.

The Mazenod Lake region of the southern Great Bear Magmatic Zone (GBMZ) of the Northwest Territories, Canada comprises the north-central portion of the Faber volcano-plutonic belt. Mazenod geology is dominated by rhyodacite to basaltic-andesite ignimbrite sheets with interlayered volcaniclastic sedimentary rocks dominated by fine-grained laminated tuff sequences. Much of the intermediate to mafic nature of volcanic rocks is disguised by low-intensity but pervasive metasomatism. The region is affected by a series of coalescing magmatic-hydrothermal systems that host the Sue-Dianne magnetite-hematite IOCG deposit and several related showings including magnetite, skarn, and IOA styles of alteration ± mineralization. Exposed at surface are dominantly mid to upper levels of these systems, with underlying batholith, pluton and stocks exposed along the periphery, as well as locally within volcanic rocks associated with more intense alteration and mineralization. Widespread alteration includes potassic and sodic metasomatism, and silicification with structurally controlled giant quartz complexes. Localized tourmaline, skarn, magnetite-actinolite, and iron-oxides occur within structural breccias, and where most intense formed the Sue-Dianne Cu-Ag-Au diatreme-like breccia deposit. Magmatism, volcanism, hydrothermal alteration and mineralization formed during a negative tectonic inversion within the Wopmay Orogen. This generated a series of oblique offset rifted basins with continental style arc magmatism and extensional structures unique to GBMZ rifting. All significant hydrothermal centres in the Mazenod region occur along and at the intersections of crustal faults either unique to or put under tension during the GBMZ inversion.

The hydrothermal synthesis of aluminophosphate molecular sieve type AlPO4-11 was processed from chemicals containing psueudobohemite, 85% phosphoric acid, water, and di-isopropylamine as templating agent. The crystallization of the samples was studied by taking samples in times from 2 to 74 hours. The obtained white powder products have been characterized by XRD patterns, FT-IR spectra, thermogravimetric data, scanning electron microscopy and pH measurement of the mother liquor. The pore volume, as determined from TG and DTG curves, was ca. 0.17 cm3g-1. The crystallization process of the aluminophosphate exhibited in its initial phase a behavior of first order reaction with a specific velocity constant of ca. 0.25 h-1, as determined from XRD and FT-IR data.

We report the influence of ammonium hydroxide (NH4OH), as growth additive, on zinc oxide nanomaterial through the optical response obtained by photoluminescence (PL). A low-temperature hydrothermal process is employed for the growth of ZnO nanowires (NWs) on seedless Au surface. A more than two order of magnitude change in ZnO NW density is demonstrated via careful addition of NH4OH in the growth solution. Further, we show by systematic experimental study and PL characterization data that the addition of NH4OH can degrade the optical response of ZnO NWs produced. The increase of growth solution basicity with the addition of NH4OH may slowly degrade the optical response of NWs by slowly etching its surfaces, increasing the point defects in ZnO NWs. The present study demonstrates the importance of growth nutrients to obtain quality controlled density tunable ZnO NWs on seedless conducting substrates.

Anaerobic digestion is a feasible solution for the treatment of organic wastes. The process can reduce the amount of biowaste by stabilizing the organic material and producing biogas susceptible to energetic valorization. However, the digestate needs further valorization when land application is considered unfeasible. Thermal treatments, such as gasification, pyrolysis, and hydrothermal carbonization, are alternatives capable of transforming this material into valuable syngas, obtaining, in many cases, a carbonized stream known as biochar. The feasibility of the process depends on the energy demand for the drying stage and the treatments available for removing contaminants from the syngas, attaining high-quality products, and treating the process-derived water. In the present manuscript, these critical aspects were reviewed considering the characteristics of digestates based on their origin, the modifications of this material during anaerobic digestion, and the way digestate structure affects the final thermal valorization outcome. Emphasis was placed on the energy demand of the global approach and by-product treatments.

In this work, dry and hydrothermal carbonization (DC and HTC) of RDF pellets were conducted to evaluate the physical, chemical, and fuel properties of the produced chars. In the dry carbonization tests, biomass sawdust was incorporated in different proportions on the samples to minimize agglomeration caused by the melting of the plastic fraction. The experiments were carried out in a temperature of 400°C (DC) and 250-300°C (HTC), in a residence time of 30 minutes. The respective chars and hydrochars were characterized according to their mass yield, apparent density, proximate, elemental, and mineral composition, chlorine content, high heating value, thermogravimetric profile, and surface functional groups. The results showed that dry carbonization of RDF pellets with biomass incorporation, followed by a washing step, resulted in the production of chars with improved properties such as higher fixed carbon and HHV (25-26 MJ/kg) and lower ash and chlorine content. Additionally, the HTC experiments demonstrated that hydrochars showed improved properties without the need for biomass addition and washing, however, with no significant difference in the HHV (20-21 MJ/kg). Therefore, DC of RDF pellets with 10% biomass incorporation seems to be a promising option to overcome the constraints of RDF utilization as an alternative fuel.

In recent years, cerium dioxide (CeO2) has attracted considerable attention owing to its remarkable performance in various applications, including photocatalysis, fuel cells, and catalysis. This study explores the effect of nickel (Ni) doping on the structural, thermal, and chemical properties of CeO2 nanorods, particularly focusing on oxygen vacancy-related phenomena. Utilizing X-ray powder diffraction (XRD), alterations in crystal structure and peak shifts were observed, indicating successful Ni doping and the formation of Ni2O3 at higher doping levels, likely due to non-equilibrium reactions. Thermal gravimetric analysis (TGA) revealed changes in oxygen release mechanisms, with increasing Ni doping resulting in the release of lattice oxygen at lower temperatures. Raman spectroscopy corroborated these findings by identifying characteristic peaks associated with oxygen vacancies, facilitating the assessment of Ni doping levels. Overall, this study underscores the substantial impact of Ni doping on CeO2 nanorods, shedding light on tailored catalytic applications through modulation of oxygen vacancies while preserving the nanorod morphology.

The cultivation of pea pods spans across various regions and climates with a global production of around 20 million tons. The pea peel wastes, which make up 30–40% of the total weight of the peas, are freely available in large quantities. The biomass used was characterized via ultimate, proximate, and structural analysis obtaining a 20,2 %w of cellulose and 17,4 %w of hemicellulose which via valorization processes can be transformed into platform chemicals. Hydrothermal valorization presents itself as a clean form of treatment of said wastes, ranging from 120 – 180 ºC (LHW) to 180 to 260 ºC (HTC). The use of LHW can lead to the production of sugars (up to 70%w yield) and levulinic acid (4 %w yield) while the use of HTC leads to Formic acid (40 %w) and levulinic acid (4 %w yield). The use of LHW for longer times favors the production of HMF and Furfural. The use of homogeneous catalysts (H2SO4, CH3COOH, KOH and NaHCO3) was implemented and their selectivity described. Solid fractions of LHW and HTC were characterized via FTIR and elemental analysis and the change in their structure described as they shift from biomass to biochar. Optimal conditions for each platform chemical were reported for best utilization of the peapod waste.

Biowaste management is in the center of attention in recent years, due to the increased focus on Circular Economy practices. Recent management solutions promote exploration for small and medium scale processing and monitoring practices. In this context, two pathways of biowaste valorization are analyzed: composting and anaerobic digestion. This study focuses on energy production with the hydrothermal carbonization (HTC) of anaerobic residues from biogas production. Lesvos has numerous processing facilities and olive mills, and therefore Olive Mill Wastewater (OMWW) are the main biowaste streams in the island, along with olive tree pruning, the organic fraction of municipal solid waste and sludge from wastewater treatment facilities. Most studies present applications on specific types of biowaste, while this study aims to co-treat several biowaste streams. A holistic experimental set-up that combines aerobic and anaerobic treatment strategies was developed taking into consideration the hydrothermal treatment of AD digestate along with locally available biowaste, like OMWW, sludge etc. A main target objective is to investigate if solid fraction could have a high heating potential In addition, HTC was able significantly to reduce the COD of OMWW while resulting in hydrochars with increased heating values.

The Ptarmigan and Tom mesothermal gold deposits are located 10 km to the northeast of the city of Yellowknife, Northwest Territories in northern Canada. Both gold deposits comprise a series of en echelon veins that are hosted within upper greenschist to lower amphibolite facies ~2630 Ma (peak) rocks. Supracrustal units across the craton are intruded by the ca. 2610–2605-Ma granodiorite, tonalite, monzodiorite, quartz diorite, and affiliated rocks of the Concession Suite. Hydrothermal apatite is a common accessory mineral in both mineralized and non-mineralized quartz veins in the metasedimentary host rocks that constitute the Ptarmigan and Tom deposits. This study characterizes and compares turbidite-hosted hydrothermal apatite from the Ptarmigan and Tom deposits, non-mineralized veins adjacent to the ore body, and magmatic apatite from proximal LCT-pegmatites. Using electron probe microanalyses (EPMA), laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS), micro-XRF, and cathodoluminescence (CL), the major, minor, and trace element abundances have been quantified and mapped. In addition to utilizing this data to determine if the chemistry of apatite can be used to constrain the source of hydrothermal fluids, the apparent age of the apatite is also evaluated utilizing in situ U-Pb dating. The distribution and abundance of major, minor, and trace elements from in situ recovered apatite were studied to characterize the nature of mineralizing fluids. Most apatite from mineralized and non-mineralized veins show different Mn, Sr, and Pb contents, as well as chondrite-normalized rare-earth element (REE) and Y abundance patterns. REEs display five unique chondrite-normalized patterns: (1) negative sloped pattern with slight negative Eu anomaly, (2) a flat pattern with a positive Eu anomaly, (3) a positive slope with a negative Eu anomaly, (iv) light rare earth element (LREE) depleted pattern with positive Eu anomaly, and (v) bell-shaped pattern with a negative Eu anomaly. The REE patterns reflect both the source of the auriferous hydrothermal fluids and, perhaps, co-precipitating mineral phases. Apatite from the Ptarmigan vein occurs with both: (1) a flat pattern with a positive Eu anomaly and (2) bell-shaped pattern with a negative Eu anomaly. The bell-shaped and flat patterns typify orogenic gold deposits. Vein-hosted apatite commonly displays compositional zoning with a characteristic yellow cathodoluminescence (CL) emission spectra with darker cores and brighter rims. The cores have lower REE, whereas the rims are notably higher in REE. It is thought that the darker cores in CL images reflect a transition from an early low REE hydrothermal fluid to one enriched in REE. The hydrothermal apatite age of 2585 ± 15 Ma is consistent with the intrusions of the 2605 and 2590 Ma two-mica granites of the Prosperous Suite and associated LCT pegmatites.

Synthesis of zeolite T with a variety of desired characteristics necessitate extensive work in the formulation and practical experiments either by conventional hydrothermal methods or aided with different approaches and synthesis techniques such as secondary growth or microwave irradiation. The objectives of this review are to adduce the potential work in zeolite T (Offretite-Erionite) synthesis evaluating determining factors affecting the synthesis and quality of the zeolite T crystals. Attention is given to the extensive studies that interconnect with other significant findings.

Polyvinyl chloride (PVC) electric wires were subjected to dechlorination in subcritical water at three different temperatures in a high-pressure reactor. About 2.09, 73.08 and 95.96 wt. % of chlorine in PVC wires was removed during dechlorination at 200, 250 and 300 °C, respectively. The solid residues were analyzed and characterized by thermogravimetry, at three different heating rates (5, 10 and 20 °C/min) in inert and oxidizing atmosphere. With the purpose of studying the emission of chlorinated pollutants, pyrolysis experiments at 850 °C were also performed in a laboratory scale reactor with the dechlorinated materials, as well as with the original PVC electric wire. Polycyclic aromatic hydrocarbons (PAH) formation increased, but chlorobenzenes (ClBz) and chlorophenols (ClPh) formation decreased as the temperature of dechlorination increased; naphthalene was the most abundant PAH and monochlorobenzene and monochlorinated phenols (3-+4-) were the most abundant chlorinated compounds.

Humification is a promising strategy to reduce the amount of animal waste generated in agriculture. This makes it possible to accumulate products with artificially obtained humic substances (HS) as analogues of natural HS, usually extracted from fossil sources (coal, peat). The review examines the main characteristics of various biological and physical-chemical methods (composting, anaerobic digestion, pyrolysis, hydrothermal carbonation, acid or alkaline hydrolysis, subcritical water ex-traction) used to form HS in animal waste humification products. A comparative analysis of the humification rates and yields of HS in these processes, the characteristics of artificial HS in products (humification index, polymerization index, degree of aromaticity, etc.) is carried out in connection with the use of certain methods of humification and types of animal waste. The main factors (ad-ditives, process conditions, waste pretreatment, etc.) that can increase the efficiency of humification and the properties of HS resources artificially obtained by various methods are highlighted. A generalizing analysis of the content of chemical elements in artificial HS obtained from various animal husbandry wastes in comparison with natural HS was carried out. Based on the results of the chemical composition analysis, the main trends and preferences regarding the most useful ap-plications of humification products as complex biomimetics are discussed.

Hydrothermal carbonization of cellulose was examined at 240 ℃ for 1 h. Ammonium sulfate and thiourea were selected as the doping sources of inorganic nitrogen and organic nitrogen for the preparation of supercapacitor carbon. The effect of boric acid on the properties of the resulting hydrochar after KOH activation was examined. The results showed that the proportion of functional groups and the specific surface area of the activated hydrochar would be reduced after the addition of boric acid, and the pore-forming process of the micropores would be inhibited. The hydrochar obtained from the reaction of cellulose and organic nitrogen compounds had better pore size distribution and electrochemical properties after activation. The largest specific surface area (952.27 m2 g-1) was obtained when only thiourea was used as the only doping source. In the three-electrode system, the specific capacitance resulting activated hydrochar reached 236.25 F g-1 at a current density of 1 A g-1. After 20,000 cycles of charging and discharging at a current density of 10 A g-1, the capacitance retention rate reached 99.96%. Therefore, this study proves that the supercapacitor carbon with good electrochemical properties could be obtained by the direct reaction of cellulose with organic nitrogen compounds.

Building heterojunction is promising strategy for the achievement of highly efficient photocatalysis. In this study, a novel SnIn4S8@ZnO Z-scheme heterojunction with tight contact interface was successfully constructed through a facile two-step hydrothermal method. The phase composition, morphology, and photophysical properties of SnIn4S8@ZnO were studied through a series of characterization methods, respectively. Methylene blue (MB) was selected as the target pollutant for photocatalytic degradation and the degradation process was fitted with pseudo-first order kinetics. The as-prepared SnIn4S8@ZnO heterojunctions exhibited outstanding photocatalytic activities for the degradation of MB. The optimized sample (ZS800), in which the molar ratio of ZnO to SnIn4S8 was 800, displayed the highest photodegradation efficiency of MB (91%) within 20 min. Furthermore, the apparent rate constant of photodegradation for MB of ZS800 (0.121 min−1) was 2.2 times higher than that of pure ZnO (0.054 min−1). The improvement of photocatalytic activity could be attributed to the effective spatial separation of photogenerated charge carriers through a Z-scheme heterojunction with intimate contact interface. This work will provide a new insight into constructing excellent ZnO-based photocatalytic systems for wastewater purification.

In this paper, mineralogical and elemental geochemical characteristics of massive sulfide samples collected from Jade hydrothermal field, located in the Izena depression in the central graben of Okinawa Trough, were analyzed by means of optical microscopy, scanning electron microscopy and electron probe. The results show that the sulfide in Jade hydrothermal area can be divided into Zn-Cu-Pb rich massive sulfide and Zn-Fe rich massive sulfide. The former is composed of sphalerite, galena, anglesite, chalcopyrite and pyrite, and its formation stage can be divided into pyrite stage, sphalerite-chalcopyrite stage, anglesite stage and colloidal pyrite stage. The latter is mainly composed of sphalerite, pyrite, marcasite and a small amount of galena, which can be divided into galena stage, pyrite stage, sphalerite stage, pyrite and marcasite stage. Cu and Zn in pyrite may exist in the form of microinclusions, while Ag and Pb may exist in pyrite in the form of fine galena inclusions containing Ag. Fe and Cu may enter sphalerite in the form of ion replacement. Zn may enter chalcopyrite in the form of ion replacement, and As and Pb may be inclusions in chalcopyrite as As-bearing galena inclusions. Consistent with the previous understanding, the metal elements in the hydrothermal liquid system in Jade hydrothermal field mostly migrate with the hydrothermal fluid as sulfur complexes, and when the hydrothermal fluid mixes with seawater, the physical and chemical conditions of the fluid change, resulting in sulfide mineral precipitation. However, the chemical structure of chalcopyrite is still controversial, which restricts the understanding of the substitution mechanism of trace elements during chalcopyrite precipitation.

A hydrothermal pretreatment of the microalga Nannochloropsis gaditana at mild temperatures has been studied in order to reduce N and O content in the biocrude obtained by hydrothermal liquefaction (HTL). The work is focused on the evaluation of temperature, reactor loading and time (factors) to maximize the yield of the pretreated biomass and the heteroatom contents transferred from the microalga biomass to the aqueous phase (responses). The study followed the factorial design and response surface methodology. An equation for every response has been obtained, which leads to the accurate calculation of the operating conditions required to obtain a given value of these responses. Temperature and time are critical factors with a negative effect on the pretreated biomass yield, but a positive one on the N and O recovery in the aqueous phase. The slurry concentration has to be low to increase heteroatom recovery and high to maximize the pretreated microalga yields

Honeycomb-like CO₃O₄ nanosheets with high specific surface area were successfully synthesized on porous nickel foam by the facile hydrothermal method followed by an annealing treatment (300 °C), which were used as high-performance supercapacitor electrodes. The effects of mole ratio of hexamethylenetetramine (HMT) and Co(NO₃)₂ (1:1, 2:1, 3:1, 4:1, 5:1 and 6:1）as the reactants on morphological evolution and electrochemical performance of the electrodes were investigated in detail. X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy and scanning electron microscopy were applied to characterize the structure and morphology of the products. The electrochemical performance was measured by cyclic voltammetry (CV) and galvanostatic charge/discharge. The results indicated that phase constituents were almost unaffected with the change in mole ratio of HMT and Co(NO₃)₂. However, the significant morphological evolution of Co₃O₄ was observed with increasing the mole ratio, which was described as followed: the nanosheets accompanied with a large number of spherical nanoparticles→the formation of some strip-like particles due to the agglomeration of spherical nanoparticles→the formation of new nanosheets resulting from the growth of strip-like particles→the formation of coarse flower-like particles owing to the connection among the nanosheets→the nanosheets gradually covered with flower-like particles. Accompanied with the change, the specific surface area was increased firstly, and then decreased. A maximum was obtained in the HMT and Co(NO₃)₂ mole ratio of 4:1, which was further validated by CV and galvanostatic charge/discharge tests. The specific capacitance value was 743.00 F·g^-1 at 1 A·g^-1 in the galvanostatic charge/discharge test, which was apparently higher than those in the other mole ratios (139.11 F·g^-1 in 1:1, 280.46 F·g^-1 in 2:1, 503.29 F·g^-1 in 3:1, 463.75 F·g^-1 in 5:1 and 363.74 F·g^-1 in 6:1). The change was also observed in the CV test with a scanning rate of 5 mV·s^-1 (121.32 F·g^-1 in 1:1, 217.33 F·g^-1 in 2:1, 559.86 F·g^-1 in 3:1, 693.56 F·g^-1 in 4:1, 423.35 F·g^-1 in 5:1 and 321.64 F·g^-1 in 6:1). Co₃O₄ synthesized in the mole ratio of 4:1 also demonstrated an excellent cyclic performance, in which about 97% of the initial specific capacitance was remained at 1 A·g^-1 for 500 cycles in the galvanostatic charge/discharge test. This excellent electrochemical performance was ascribed to high specific surface area of Co₃O₄ nanosheets that provide enough channels and space for ions transportion.

Ferroelectric materials are crucial for today’s technological society, and nanostructured ferroelectric materials are important for downscaling of devices. Controlled and reproducible synthesis of these materials are therefore of immense importance. Hydrothermal synthesis is a well-established synthesis route, with a large parameter space for optimization, but a better understanding of nucleation and growth mechanisms is needed for full utilization and control. Here we use in situ X-ray diffraction to follow the nucleation and growth of BaTiO₃ formed by hydrothermal synthesis using two different titanium precursors, an amorphous titania precipitate slurry and a Ti-citric acid complex solution. Sequential Rietveld refinement was used to extract the time dependency of lattice parameters, crystallite size, strain and atomic displacement parameters. Phase pure BaTiO₃ nanoparticles 10 - 15 nm in size were successfully synthesized at different temperatures (100, 125, and 150 °C) from both precursors after reaction times ranging from a few seconds, to several hours. The two precursors resulted in phase pure BaTiO₃ with similar final crystallite size. Finally, two different growth mechanisms were revealed, where the effect of surfactants present during hydrothermal synthesis is discussed as one of the key parameters.

Synthesis of activated carbon from waste biomass is of current interest towards sustainability. The properties of biomass derived activated carbon largely depends on the carbonization process. This study reports preparing extremel high surface area mesoporous activated carbon from hemp bast fibre using hydrothermal processing. Processing in hot water (390-500^oC), then activation using KOH and NaOH was investigated at different loading ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp derived activated carbon (HAC) from activation (confirmed by BJH pore size distribution and TEM imaging). BET results showed that the product has an extremely high surface area (2425 m²/g) while the surface functional groups (-OH, COOH, C=C/C-C) were confirmed and quantified by XPS and FTIR results. Increasing KOH concentration was found to enhance the surface area with an optimum biochar to KOH ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.

This article discusses the results of fluid inclusions study in barite collected at the Jan Mayen vent field area (Troll Wall and Perle & Bruce) and Loki’s Castle vent field of the Mohns Ridge segment of the Arctic Mid-Ocean Ridge. Three mafic-hosted volcanogenic massive sulfide deposits were examined within the active vent fields that adequately correspond to geological settings of ultraslow-spreading ridges and PT-conditions. Hydrothermal sediments were investigated to determine the temperature and salinity of the fluids responsible for barite precipitation. The hydrothermal origin of the barite was confirmed by its morphology. Fluid inclusions are two-phase and homogenized into the liquid phase on heating at temperatures below 287ºC. The salt concentration in fluids trapped in inclusions is 2.6–4.4 wt.% NaCl eq. The crystallization temperatures varied from 276ºС to 119ºС and from 307ºС to 223ºС for the Jan Mayen and Loki’s Castle vent fields, respectively. The data obtained allowed us to confirm evidence of fluid phase separation in the hydrothermal systems and to expand our knowledge of the temperature and salinity of mineral fluids previously known from recent direct measurements during the cruises within the G.O. Sars research vessel. The fluid inclusions data obtained from barites emphasize the fluid features characteristic of volcanogenic massive sulfide deposits, the similarities and differences for the studied hydrothermal sites, and allow comparisons with similar products from other active hydrothermal systems.

Poultry litter was converted to biochar by torrefaction and to hydrochar by hydrothermal carbonisation. Many parameters were measured for the resulting chars, to investigate the effect of production method and production temperature. SEM showed the presence of large quantities of crystalline material on the surface of the biochars. The elemental composition of some crystals was determined as 35% K and 31% Cl. This was confirmed as sylvite (KCl) crystals, which explains the high levels of water extractable potassium in the biochar and may also be important in germination inhibition. Biochars almost totally inhibited germination, whilst hydrochars decreased germination. Although germination occurred on hydrochar, root growth was severely inhibited. Consequently, germination index may be better to determine total phytotoxicity as it measures both effects and could be used as a bioassay for chars used as soil amendments. Washing removed germination inhibition in a low temperature char (3500C), possibly by removing KCl, however root toxicity remained. There were very low levels of heavy metals, suggesting they are not the source of toxicity. In biochars, pore mean size decreased with temperature from 3500C to 6000C, due to changes in pore size distribution. Mean pore size was measured directly using SEM. The merits of this method are discussed. Low temperature biochars seem best suited for fuel as they have high calorific value, high hydrophobicity, low ash content and high yield. Higher temperatures are better for soil amendment and sequestration applications with a smaller mean pore size, higher surface area, and higher pH.

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with circular economy and biorefinery principles. SWE was carried out at 145 °C, 50 bar and 50 min in a discontinuous reactor, producing a phenolic-rich extract (32 ± 3 mg/g), dominated by protocatechuic acid (20 ± 3 mg/g), quercetin-4´-O-glucoside (7.5 ± 0.2 mg/g), and quercetin (3.2 ± 0.6 mg/g). Additionally, it contains sugars (207 ± 20 mg sucrose-Eq/g), proteins (22.8 ± 1.6 mg BSA-Eq/g) and free amino acids (20.4 ± 1.2 mg arginine-Eq/g). Its phenolic richness determines its scavenging activity against ●NO and O2●- radicals, and its α-glucosidase and aldose-reductase inhibition without affecting α-amylase. Notably, the extract demonstrates significant α-glucosidase inhibition (IC50 = 76 ± 4 µg/mL), surpassing acarbose (IC50 = 129.5 ± 1.0 µg/mL), in both pure enzyme and cell culture tests without showing cytotoxicity on AGS, HepG2 and Caco-2 human cell lines. The extract’s bioactivity and nutritional content make it suitable for developing antioxidant and antidiabetic nutraceutical/food components, highlighting the SWE potential for OSW valorization without using organic solvents.

Colombia is the world's leading producer of mild washed arabica coffee and produces 12.6 million bags of green coffee, but at the same time 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used. The objective of this project was to evaluate the production of platform chemicals from these coffee wastes. To achieve this, biomass characterization was carried out using proximate analysis, ultimate analysis and structural analysis. Hydrothermal valorization was carried out at a temperature range of 120-180 °C (LHW) and 180-260 °C (HTC) for one hour, the platform chemicals obtained were quantified by HPLC-IR, monitored by pH and conductivity, and the solid fraction was characterized by monitoring the functional groups in IR spectroscopy, and elemental analysis. Hydrolysis processes were obtained from 150 °C, production of platform chemicals from 180 °C and maximum concentration at 180 °C-4h, over 200 °C degradation of the products in the liquid fraction starts to take place. Homogeneous basic and acid catalysts were used to improve the yields of the reaction. The kinetics of the hydrolysis of lignocellulosic structures to sugars were also analyzed and described, and reaction orders of 1 (LHW), 3 (HTC) and their respective reaction rate equations were reported.

Water electrolysis is a highly efficient route to produce ideally clean H2 fuel with excellent energy conversion efficiency and high gravimetric energy density, without producing carbon trace unlike steam methane reforming, and resolves the issues of environmental contamination via replacing the conventional fossil fuel. Of special importance lies in the advancement of highly effective non-precious catalysts for the oxygen evolution reaction (OER). The electrocatalytic activity of an active catalyst mainly depends on the material conductivity, accessible catalytically active sites, and intrinsic OER reaction kinetics, which can be tuned via introducing heteroatom N in the catalyst stricture. Herein, an efficacious nitrogenation of CuS has been accomplished, which was synthesized using hydrothermal procedure, and characterized for their electrocatalytic activity towards OER. The nitrogen-doped CuO@CuS (N,CuO@CuS) electrocatalyst exhibits superior OER activity than pristine CuS (268 and 602 mV), achieving the low overpotential of 240 and 392 mV at a current density of 10 and 100 mA/cm2, respectively, ascribed to the favorable electronic structural modification triggered by nitrogen incorporation. The N,CuO@CuS also exhibits excellent endurance under varied current rates and a static potential response over 25 h stability measured at 10 and 100 mA/cm2.

Developing low-cost and stable materials for converting solar energy into electricity is vital in meeting the world's energy demand. Metal-organic frameworks (MOFs) have gained attention for solar cells due to their natural porous architectures and tunable chemical structures. This review commences with an exploration of the synthetic methods of MOFs. Moreover, we discuss the various roles of MOFs, including photoanodes and counter electrodes in dye-sensitized solar cells and interfacial layers and charge carriers in perovskite solar cells. Ultimately, burdensome tasks and possible directions for advancing MOFs-based nanomaterials are provided for solar cells.

The topography and chemical composition modification of the titanium (Ti) implants play a decisive role in improving biocompatibility and bioactivity, accelerating osseointegration, and, thus, determining clinical success. In spite of the development of surface modification strategies, bacterial contamination is a common cause of failure. The use of systemic antibiotic therapy does not guarantee action at the contaminated site. In this work, we proposed a surface treatment for Ti implant that aim to improve its osseointegration and reduce bacterial colonization in surgery site due to local release of antibiotic. The Ti disks were hydrothermally treated with 3M NaOH solution to form a nanostructured layer of titanate on the Ti surface. Metronidazole was impregnated on these nanostructured surfaces to allow its local release. The samples were coated with poly(vinyl alcohol) - PVA films with different thickness to evaluate a possible control of drug release. Gamma irradiation was used to crosslink the polymer chains leading to a hydrogel layer formation and to sterilize the samples. The samples were characterized by XRD, SEM, FTIR, contact angle measurements, “in vitro” bioactivity, and drug release analysis. The alkaline hydrothermal treatment successfully produced intertwined, web-like nanostructures on the Ti surface, providing wettability and bioactivity to Ti samples (Ti+TTNT samples). Metronidazole was successfully loaded and released from Ti+TTNT samples coated or not with PVA. Although the polymeric film acted as a physical barrier to drug delivery, all groups reached the minimum inhibitory concentration for anaerobic bacteria. Thus, the surface modification method presented is a potential approach to improve the osseointegration of the Ti implant and to associate local drug delivery to dental implants, preventing early infections and bone failure.

This paper presents the life cycle assessment results of a study of plastic recycling via hydrothermal upgrading (HTU), a chemical recycling technology. It was investigated due to its potential to address current gaps in the plastic recycling system, largely due to several plastic packaging materials and formats that cannot be processed by traditional mechanical recycling technologies (primarily due to technoeconomic reasons). As society transitions towards a net-zero-based circular economy, assessments should be conducted with a futuristic outlook, preventing costly mistakes by employing the right technologies in the right areas. HTU can generate up to 76% reduction in climate change impacts when compared with comparable end-of-life treatment technologies whilst conserving material with the system. Additionally, further reductions could be achieved by changes in electricity consumption within the study. This represents a new insight to chemical recycling of polymers by establishing a prospective life cycle assessment study that looks to introduce a step-change in the recycling system. By creating a transparent cut-off model with consistent allocation, it highlights the benefits of introducing this technology as opposed to the current model of disposal through incineration or landfill.

Li4Ti5O12 (LTO) exhibits zero-strain behavior, exceptional cycle stability, low cost, and high safety. However, it is still low in electronic and ionic conductivity. Incorporating Sn into LTO materials can increase electronic conductivity and specific capacity. However, Sn still experiences volumetric expansion during the charging/discharging process. Adding activated carbon (AC) into the LTO/Sn composite can help improve the expansion resistance and electronic conductivity. In this work, the AC was first synthesized from charcoals through the carbon activation process and mixed with LTO precursors through the sol-hydrothermal method followed by mixing with Sn through the mechanochemical process to produce LTO@AC/Sn composites. The Sn content was fixed at 15 wt.%, while the AC contents were varied at 1 wt.%, 3 wt.%, and 5 wt.%. The AC specific surface area is increased by more than 100% compared to the non-activated one. The best effects of AC on grain morphology and distribution were found in the LTO/Sn contained 3 wt.% of AC, leading to transfer resistance, ohmic resistance, specific capacity, and coulombic efficiency were found to be 48.1 Ω, 8.5 Ω, 138 mAhg-1, and near 100%, respectively. The result suggests that the LTO@AC/Sn could be a favorable anode active material in lithium-ion batteries.

In the present study, we have followed the hydrothermal path for the synthesis of gold nanoparticles (Au NPs) from the biomaterial Elaeocarpus ganitrus seeds extract, which is a rapid, eco-friendly, non-chemical way. The prepared NPs were thoroughly analyzed by PXRD & HR-TEM studies and also tested for photocatalytic dye degradation and anticancer studies. Besides, antioxidant, antibacterial and anticancer properties of Au NPs were studied. In vitro studies revealed the dose-dependent cytotoxic effect of Au NPs. The prepared nanoparticles showed good cytotoxic impact against Prostate cancer (PC-3) cells line. The results of the present study could contribute to synthesize new and cost-effective drugs from Elaeocarpus ganitrus seeds extract by using bio approach.

Photoelectrocatalytic water splitting by using various TiO₂ nanostructures is a promising approach to generate hydrogen without harmful byproducts. However, their effective performance is restricted by some drawbacks such as high rapid electron-hole pair recombination and backward reaction producing H₂O. Thus in this study, the probability of enhancing hydrogen generation rate by adding methanol as a sacrificial agent to the anodic chamber of a two-compartment photoelectrochemical cell is investigated. Herein, one-dimensional elongated TiO₂ nanorods that were fabricated via a facile one-pot hydrothermal method are utilized as potent photoanode. Voltammetric characterizations confirm that addition of alcoholic sacrificial agent has a significant effect on photoelectrochemical properties of TiO₂ nanorods which by adding 10 wt% of methanol, the photocurrent density and photoconversion efficiency increased from 0.8mA.cm^-2 to 1.5mA.cm^-2 and from 0.28% to 0.45%, respectively. The results of photoelectrocatalytic water splitting indicated that the hydrogen generation rate in the presence of methanol was about 1.2 times higher than that from pure water splitting. These enhancements can be attributed to the key role of methanol. Methanol molecules not only inhibit the electron-hole pair recombination but also accelerate the hydrogen generation rate by sharing their hydrogen atoms.

Currently there is little doubt left on the symbiogenetic nature of eukaryotes - genomes of archaeon and bacterium participated in shaping a genome of last eukaryotic common ancestor in equal albeit asymmetric manner, while a merger event itself indicated the advent of a new domain of life. The “symbiogenetic” framework of interaction of two partners is proposed, outlining similar steps essential for three major advents: the origin of life, the origin of complex life and the origin of humans. Given the immense importance of proper energy source for the evolution of life it seems plausible that for any principal increase in complexity, a partnership with a novel energy donor is required. Moreover, a “language” elaborated in the course of communication of partners might have been a prerequisite for a subsequent increase in complexity. Transitions, which led to RNA-protein world, eukaryotes and human brain, resulted in advent of complex languages via communication onsets between two entities in close partnership. Accordingly this further facilitated formation of first cells, multicellular organisms and human society.

Listwaenite rocks are widely spread in Fenja area of the Semail ophiolite of Oman and in Islam Abad area of the Neyriz ophiolite of Iran. There are three types of listwaenites found in these regions: silica-, carbonate-, and carbonate-silica (which includes dolomite, calcite, and magnesite. The alteration of host harzburgites started with hydrothermal alteration to serpentinite, followed by carbonation and silicification of serpentinite. Calcite- and magnesite-dolomite- listwaenites are more abundant in the Fenja area of Oman, while dolomite-listwaenites are more abundant in Islam Abad area in Iran. The mineralogy of listwaenites varies in both Iran and Oman; common minerals include quartz, calcite, goethite, magnesite, dolomite, serpentine, hematite, magnetite, Cr-mica, and Cr-spinel The major element chemistry of the different types of listwaenites in both Fenja and Islam Abad area generally comparable, and is largely similar to that of hydrothermally carbonated harzburgites, serpentinite, and listwaenites worldwide, despite spanning extraordinary and highly variable contents in major oxides, such as CaO, SiO2, MgO and LOI. Relict texture and common occurrence of Cr-spinel as well as the high concentrations of Cr, Ni and Co suggest that the protolith of the listwaenites in both regions was serpentinized harzburgites and serpentines. In comparison to the primary mantle and chondrite in spider diagrams, the Neyriz listwaenites have higher trace and REE element abundances than comparable listwaenites in the Fenja region. Harzburgite-normalized patterns of trace elements and REE in serpentinite and listwaenites overlap the average composition of harzburgite. PM-normalized trace element and REE patterns for serpentinized harzburgite and serpentinite show enrichment in Cs, U, Pb and Sr, with no Eu anomaly, comparable to mantle wedge serpentinites. The variable and high abundances of Ca, Mg, Ba, Zr, Sr, Pb, Zn, Mo and W in the carbonate- and silica-carbonate listwaenites, with unique Si enrichment and Mg, Na2O, Zr, Y, Ba, Sr, Rb, Cu, Pb, Sc, Cs, Nb, Mo and W. depletion in silica listwaenites are indicative of large fluctuations in major and trace element mobility. Cr, Ni and Co were immobile during alteration Enrichment in Ca and Si could occur by internal or late outside supply. Ca, Mg and Si are conceivably the foremost mobile major components amid harzburgite and serpentinite carbonation with mobilization confirmed by formation of quartz and Mg-carbonate in silica-carbonate listwaenites and quartz in silica listwaenites. The listwaenites in Islam Abad and Fenja area were formed due to hydrothermal alteration of serpentinite along thrust faults and shear zones which acted as pathway for Ca and/or Si rich fluids. The intensity of deformation in Islamabad listwaenites has been higher than Fenja listwaenites as indicated by higher abundance of trace elements.

This study investigated different conditions for the hydrothermal co-liquefaction (co-HTL) of sugarcane bagasse and residual cooking soybean oil, with and without the presence of ethanol as a cosolvent to maximize the bio-crude yield. All co-HTL reactions were carried out in a 300 mL Parr® reactor at temperatures ranging from 200 to 300 °C. Bio-crude yields of around 95 wt.% were obtained at 300 °C using ethanol and water as solvents. The highest biochar yield (16.6 wt.%) was achieved when using only sugarcane bagasse as substrate, without the presence of soybean oil. Bio-crude samples obtained at higher temperatures (280 °C and 300 °C) using ethanol as a hydrogen donor presented higher contents of both free fatty acids and fatty acid ethyl esters. This work presents a promising process to produce high-quality bio-crude using an abundant feedstock (sugarcane bagasse) in the presence of a lipid source which could cause environmental problems if poorly handled.

The Shitouping pluton in Jiangxi Province, southern China, hosts an ion-adsorption heave rare earth element (HREE) deposit identified by recently geological survey. This study reveals the HREE pre-enrichment mechanism during the magma-hydrothermal process of granitic bedrock based on the comprehensive study of zircon structure and composition. Zircon from the Shitouping pluton, composed of syenogranite and monzogranite, can be categorized into three types based on structure and compositions. The Type-1 zircons, the predominate type in monzogranite granite, are early magmatic zircons with prismatic crystals and bright oscillatory zoning. In contrast, the late magmatic-hydrothermal zircons (Type-2 and Type-3) are mainly occurred in the syenogranite. The Type-2 zircons occur as murky euhedral crystals crystallized in the late magmatic stage. The Type-3 zircons with irregular zoning and abundant mineral inclu-sions in BSE images are closely associated with Type-2 zircons, possibly formed via intense hy-drothermal alteration during the hydrothermal stage. The increase in Y/Ho ratios from Type-1 to Type-3 zircon indicates that the Shitouping syenogranites underwent magmatic to hydrothermal evolution. Compared with Type-1 and Type-2 zircons, Type-3 zircons exhibit the highest con-centrations of F and HREEs. The significant increase of HREE concentrations both in zircons and bulk-rock composition of syenogranite can be attributed to the introduction of HREE-rich fluids during magma evolution. Under this condition, the HREEs mainly hosted in fluorocarbonates, which can easily release HREE3+ to generate ion-adsorption deposits during the weathering process. Therefore, we propose that increase of HREE contents in zircon reflect the exsolution of HREE-rich fluids during the magma evolution, which is important factor controlling HREE en-richment in Shitouping syenogranites and further generation of ion-adsorption HREE deposits.

The compositions of metalliferous sediments which is associated with hydrothermal vents can provide reliable geochemical indicators for the exploration of seafloor sulfides. In this study, surface sediments from the Xunmei hydrothermal field (HF) on the South Mid-Atlantic Ridge (SMAR) were selected, and their major and trace elements were analysed. The results showed that the sediments are composed of pelagic material (calcium biogenic components), basaltic debris, iron-manganese oxides, and a mixture of hydrothermal components. Additionally, the sediments were found to be significantly enriched in Cu, Zn, Fe and Co derived from hydrothermal sources, as well as Mn, V, Mo, U and P, which are primarily scavenged from seawater. The Cu and Zn concentrations are highest in the northeastern part of Xunmei, while the northeastern, northern, and southern parts are characterized by great inputs of hydrothermal Fe. Manganese and Mo are mainly enriched in the western and southern parts and show a strong positive correlation, indicating that Mo is mainly scavenged by Mn oxides. There are high positive correlations among U, P, and Fe, indicating their coprecipitation with Fe from hydrothermal plumes. Vanadium and Co are introduced into sediments in two ways, i.e., V is scavenged and coprecipitates from hydrothermal plumes, and Co is derived from sulfide debris. Based on the variations in Cu and Zn contents and in the Cu/Fe (0.159), Zn/Fe (0.158), and Fe/Mn (1440) ratios, it can be inferred that a high-temperature hydrothermal vent existed in northeastern Xunmei. In combination with the distribution patterns of the above elements, the hydrothermal vents in the southern part ceased erupting after a short period of activity. In addition, the high Mn anomaly and the high U/Fe ratios at the boundaries of the investigated area indicate the presence of a relatively oxidized environment in southwestern Xunmei.

The emergence of Life has been a subject of intensive research for decades. Different approaches and different environmental “cradles” have been studied, from space to the deep-sea. Since the recent discovery of a natural electrical current through the deep-sea hydrothermal vent, a new energy source is considered for the transition from inorganic to organic. This energy source is used by modern microorganisms using a new trophic type, called electrotrophy. In this review, we draw the parallel between this metabolism and a new theory for the emergence of Life based on this electrical electron flow. Each step of the creation of Life is revised in the new light of this prebiotic electrochemical context, going from the evaluation of similar electrical current during the Hadean, the CO electroreduction into a prebiotic primordial soup, the production of proto-membranes, the energetic system inspired of the nitrate reduction, the proton gradient, and the transition to a planktonic proto-cell. Finally, this theory is compared to the two other theories in hydrothermal context, to assess its relevance to overcome the limitations of each one. Many critical factors that were limiting each theory can be overcome with the effect of the electrochemical reactions and the environmental changes produced.

An activated carbon manufacturing process using winemaking waste is analyzed and designed at industrial scale. Starting from experimental research, the chemical transformations and thermodynamics during pruning wood conversion are studied as a basis for plant design. In this way, mass and energy balances of hydrothermal carbonization and physical activation are fulfilled and a thermoeconomic methodology is applied to develop an energy-integrated plant. To achieve this target, a network of heat exchangers is allocated to minimize heat consumption and supply hot domestic water, while a cogeneration cycle is designed to provide electricity and satisfy the remaining heat demand. Furthermore, a sensitivity analysis is carried out to determine the influence of the production scale and other operation parameters, such as annual workload, service life, and capital and feedstock costs, on the economic viability of the plant. The energy balance of the plant indicates that the energy integration design manages to provide 48.9% of the overall process energy demand by crossing hot and cold streams and recovering heat from residual flue gas. On the other hand, the exergy cost analysis identifies the combustion of pruning wood used to provide heat demands as the main source of exergy destruction, confirming the suitability of integration to improve the thermodynamic performance. Including activated carbon production, electricity, and hot domestic water, the exergy efficiency of the plant stands at 11.5%.

Magnetic iron oxide particles are used for in vitro diagnostics for nearly 40 years. Due to their unique physical, chemical, thermal and mechanical properties, as well as biocompatibility and low toxicity in the human body, iron oxide nanoparticles have been used in many biomedical applications, such as contrast agents for magnetic resonance imaging, carriers for controlled drug delivery and immunoassays, but also in magnetic hyperthermia. Our aim is to investigate the effect of pressure and temperature on the structural, thermal and magnetic properties of iron oxide nanomaterials prepared by hydrothermal synthesis. Iron oxide nanoparticles were synthesized at temperatures of 100-200°C and pressures of 20-1000 bar. It has been found that pressure influences the type of iron oxide crystalline phase. Thus, for lower pressure values (< 100 bar), iron oxide is predominantly formed as hematite, while at pressures > 100 bar, the major crystalline phase is goethite. The complex thermal analysis revealed the polymorphic changes of iron oxides at different temperatures. The existence of specific magnetite and hematite phases in all thermally treated samples are evidenced through the specific Verwey and Morin transitions highlighted by ZFC-FC (Zero Field Cooled-Field Cooled) measurements, whereas their relative content is precisely provided by Mössbauer spectroscopy.

Ti and Ti alloys are materials usually used in contact with hard tissue for applications such as artificial joints and dental implants. Ti6Al4V is a very common alloy used for dental implants, owing to its good mechanical properties and corrosion resistance. Nevertheless, because of uncertainties regarding the toxicity of vanadium and its influence on the human body, other Ti alloys containing no vanadium and retaining suitable properties are used. In this work Ti6Al4V and Ti6Al7Nb were oxidized in a water solution of calcium acetate (Ca(CH3COO)2) and calcium glycerophosphate (Ca(PO4CH(CH2OH)2) by Plasma Electrolytic Oxidation (PEO) for 20 minutes and then were hydrothermally treated (HTT) in water (pH=7) and in potassium hydroxide (KOH) solution (pH=11) for 2 hours at 200°C in a pressurized reactor. The surface morphologies, elemental composition and phase components were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD), respectively. The surface roughness was measured by Atomic Force Microscope (AFM) and thickness measurements were made by SEM and thickness gauge. Also, corrosion tests were made to evaluate the corrosion behavior of the two alloys. The aim of this study is to compare two viable Ti alloys, Ti6Al4V and Ti6Al7Nb, and to attain on their surface hydroxyapatite (HA) coating improving the osseointegration, as it simulates a human bone.

Recent advances and demands in clinical applications drive a large amount of research to hydroxyapatite (HA) composite coatings fabricated by plasma spray. However, lower degree of HA crystallinity related to high temperature exposure in plasma spray usually leads to rapid weakening and disintegration of HA coatings and often promotes inflammatory responses in the surrounding tissue. In this research, graphene nanosheet (GNS) reinforced HA coatings were fabricated using plasma spray and followed by heat and hydrothermal treatment (hereafter referred to as thermal treatment). The addition of GNSs resulted in competing phenomenon to influence HA crystallinity viz. increased portion of the partially melted/unmelted zones and higher cooling rate during splat formation, leading to slight increase in HA crystallinity (~46.0-51.3%) in the as-sprayed coating. XRD and FTIR results showed that thermal treatment was capable of inducing significant transformation of amorphous HA to the crystalline form and removing other foreign non-HA compounds through regaining OH- ion, and therefore HA coatings displayed ~45.5-47.1% improvements in HA crystallinity regardless of addition or not of the GNS nanofillers. Microstructure observations revealed that thermal treatment enabled microcrack propagation due to stresses caused by crystallisation and phase transformations, and the residual partially melted/unmelted zone of the thermally treated GNS/HA coating was significantly decreased in size. More importantly, the added GNSs contributed greatly to the significant increase in surface nanoroughness of the thermally treated HA coatings owing to the fact that much more structural defects along with the GNSs mainly induced by thermal treatment might act as nucleation sites to accelerate HA nanoparticle precipitation, which would be beneficial for the improved adhesion strength of the osteoblast cells on the coating surface.

This article reports the two-step synthesis of NiFeO_x nanomaterials, their characterisation and bifunctional electrocatalytic activity measurements in alkaline electrolyte for metal-air batteries. The samples were mostly in layered double hydroxide at the initial temperature, but upon heat treatment, they were converted to NiFe₂O₄ phases. The electrochemical behaviour of the different samples was studied by linear sweep voltammetry and cyclic voltammetry on the glassy carbon electrode. The OER catalyst activity was observed for low mass loadings (0.125 mg cm⁻²), whereas high catalyst loading exhibited the best performance on the ORR side. The sample heat treated at 250 °C delivered the highest bi-functional oxygen evolution and reduction reaction activity (OER/ORR) thanks to its thin-holey nanosheet like structure with higher nickel oxidation state at 250 °C. This work further helps to develop low-cost electrocatalyst development for metal-air batteries.

The mesoporous heteroatom molecular sieve MCM-41 bulk crystals with the crystalline phase were synthesized via a one-step hydrothermal method using an ionic complex as template. The ionic complex template was formed by interaction between cetyltrimethylammonium ions and metal complex ion [M (EDTA)]2- (M=Co or Ni ). The materials were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N2 adsorption–desorption isotherms, and X-ray absorption fine structure spectroscopy. The results showed that the materials possess a highly ordered mesoporous structure with the crystalline phase and possess high uniform ordered arrangement channels. The structure is in the vertical cross directions with a crystalline size of about 12 µm and high specific surface areas. The metal atoms were incorporated into the zeolite frameworks in the form of octahedral coordinate and have a uniform distribution in the materials. The amount of metal complexes formed by metal ion and EDTA is an essential factor for the formation of the vertical cross structure. Comparing to Si-MCM-41, the samples exhibited better conversion, higher selectivity for cumene cracking.

The Um Ara granites are a suite of granitoid rocks located in the south Eastern Desert of Egypt. The combination of Back Scattered Electron imaging (BSE), X-ray compositional mapping, and the data of the Electron Probe Micro Analyzer (EPMA) has provided valuable insights into the alteration process of zircon in the Um Ara granite. The investigated zircon grains have measurable amount of non-formula elements such as U, Th, Hf, REEs, P, Al, Ca, Fe, and Ti, along with extensive structural features indicative of radiation damage. These characteristics point to significant hydrothermal alteration of the zircon following its initial crystallization. The textural and geochemical evidence suggests the alteration of the Um Ara zircons was driven by coupled dissolution-reprecipitation processes influenced by aqueous fluids. The breakdown of accessory minerals like xenotime, thorite, monazite, and apatite during a major hydrothermal event around 1.8 Ga released the non-formula elements (U, Th, P, Ca, Al, Fe, REEs) that were then incorporated into the zircon structures. Subsequent pluvial periods around 50,000-159,000 years ago may have allowed further uptake of these elements during low-temperature alteration. The shear zones within the Um Ara granites facilitated the mobilization and transport of the non-formula element-bearing fluids, likely as carbonate and fluoride complexes. The temperature regime, with fluids remaining below 300°C, was crucial in preserving the radiation damage features in the zircons despite the extensive chemical changes.

The 11 system in iron-based superconducting family has become one of the most extensively studied materials in the research of high-temperature superconductivity due to their simple structure and rich physical properties. However, the research on 11 iron-based superconductors faces numerous obstacles, mainly stemming from the challenges associated with producing high-quality single crystals. Since the discovery of FeSe superconductivity in 2008, researchers have made significant progress in crystal growth, overcoming the hurdles that initially impeded their studies. Consequently, they have successfully established the complete phase diagrams of 11 iron-based superconductors, including FeSe1-xTex, FeSe1-xSx and FeTe1-xSx. In this paper, we aim to provide a comprehensive summary of the preparation methods employed for 11 iron-based single crystals over the past decade. Specifically, we will focus on hydrothermal, chemical vapor transport (CVT), self-flux, and annealing methods. Additionally, we will discuss the quality, size, and superconductivity properties exhibited by single crystals obtained through different preparation methods. By exploring these aspects, we can gain a better understanding of the advantages and limitations associated with each technique.

A notable REE mineralization in Europe is associated with the Ditrău Alkaline Massif (DAM) in the Eastern Carpathians (Romania). It is an expression of the latest hydrothermal phase in the DAM and is found in the form of mineralized carbonate veins cross-cutting the complex in the NW (Jolotca region) and the SE (Belcina region) parts of the DAM. In the Belcina veins monazite-(Ce), xenotime-(Y), apatite, together with Fe-Mg-rich carbonate, thorite, thorogummite, gedrite and plagioclase are rock-forming. Three different textural and chemical types of the monazite-(Ce) and the xenotime-(Y) document a three-stage evolution. The relative phosphate age succession (from older to younger) thereby is xnt1 > xnt2 (>)+ mnz1 + Fe2O3 + Fe-gedrite > mnz2 + Fe-dolomite (+ plagioclase) > mnz3 + xnt3 + apatite. Phosphate chemistry shows that these crystallized from hydrothermal fluids, whereby each phosphate type follows a separate evolutionary path recommending growth from (at least) 3 independent and successive hydrothermal fluids. Chemistry and pathways within the DAM suggest that these hydrothermal fluids could be derived from a subsurface carbonatitic intrusion. Mnz1,2 and xnt1,2 ages are tightly cluster at 215.8 ± 0.7 Ma (Norian, Upper Triassic). The third-generation phosphate ages are younger, but associated with large analytical uncertainties and did not deliver geologically useful ages. The mean age of ca. 216 Ma is interpreted as timing the Belcina REE mineralization, what together with the fluid chemistry, supports a model of the presence of a late-stage, independent carbonatitic intrusion about 10 Ma after the main igneous activity (ca. 235 - 225 Ma) forming the DAM, synchronous with extension-related magmatism in the region.

Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, because of the complexity of the biomass (lipids, carbohydrates , and proteins), the obtained biofuels from direct thermochemical conversion have large amounts of heteroatoms (oxygen, nitrogen , and sulfur). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.

This study presents a new kinetic scheme for the mass yield prediction of waste lignocellulosic biomasses treated by Hydrothermal Carbonization (HTC). The proposed reactions are based on the decomposition, solubilization, and polymerization of each main fraction of the biomass: cellulose, hemicellulose, and lignin. The ash content was assumed to be inert. The kinetic parameters have been obtained by non-linear adjustment using a data set with 220 experimental runs collected from the literature. The results indicate that the pre-exponential factors range was from 7.33 x10¹ to 1.412x10⁵ min^-1, and activation energies were between 33.75 y 225.3 kJ/mol. A good fit is achieved between the observed and predicted data with an R² of 0.81 and an RMSE of 7.7 %. The proposed scheme was validated with the experimental data obtained by the HTC of sawdust (Pinus radiata) and rapeseed (Brassica napus). The experiments were carried out at temperatures of 190, 220, and 250 ºC and reaction times of 0, 30, 60, 90, and 120 min. The predicted values showed an average error of 2.3 and 3.5 %, respectively. Therefore, the kinetic scheme is a useful tool in the conversion analysis of waste biomass treated by HTC.

: The activated carbons (ACs) derived from okara powder waste with high surface areas were modified with ammonia aqueous solution impregnation in an autoclave to enhance their CO2 adsorption properties toward CO2. The impregnated ACs were characterized in which surface chemical composition and properties of the ACs were analyzed by SEM-EDX, FTIR. Activated carbons were functionalized with ammonia aqueous solution (25%) through a hydrothermal process within 24; 48, and 72 hours. The adsorption performance of CO2 onto carbon samples was experimentally evaluated through a TPD CO2 measurement. FTIR spectra confirm the N-containing in N-modified activated carbons and the presence of the –C = O stretch and N-H groups. CO2 uptakes of N-modified activated carbons are 0.24; 1.78; 2.24 and 1.26 mmol/g, which are relatively comparable with those of activated carbons studied in in the literature.

The activated carbons (ACs) derived from okara powder waste with high surface areas were modified with ammonia aqueous solution impregnation in an autoclave to enhance their CO2 adsorption properties toward CO2. The impregnated ACs were characterized in which surface chemical composition and properties of the ACs were analyzed by SEM-EDS, FTIR. Activated carbons were functionalized with ammonia aqueous solution (25%) through a hydrothermal process within 24; 48, and 72 hours. The adsorption performance of CO2 onto carbon samples was experimentally evaluated through a breakthrough adsorption experimental setup at room temperature. FTIR spectra confirm the N-containing in N-modified activated carbons and the presence of the –C = O stretch and N-H groups. CO2 uptakes of N-modified activated carbons are 0.24; 1.47; and 1.20 mmol/g, which are relatively comparable with those of activated carbons studied in in the literature.

Indonesia possesses significant biomass potential, including palm oil plantations. The palm oil industry has experienced rapid expansion, with a 7.67% growth rate over the past decade and an 11.09% annual increase in palm oil production. Co-firing (HT-FRD) is a beneficial technology for reducing exhaust gas emissions generated by coal-burning power stations. By utilizing Computational Fluid Dynamics (CFD), the study has modeled and evaluated co-firing palm frond residue (HT-FRD) with hydrothermal treatment into a 315 MWe boiler. In the simulation, six different HT-FRD co-firing ratios: 0%, 5%, 15%, 25%, 35%, and 50% were used to demonstrate the differences in combustion characteristics and emissions in the combustion chamber. The data indicates that HT-FRD co-firing can enhance temperature distribution, velocity, and unburned particles. All in all, co-firing conditions with 5% - 15% HT-FRD ratios appear to have the most favorable combustion temperature, velocity, and exhaust gas characteristics.

A La2FeCrO6 (LFCO) double perovskite powders were synthesized by hydrothermal method, which crystallized in an orthorhombic (Pnma) structure and exhibited a spherical morphology with average particle size of 900 nm. Fourier transformation infrared spectroscopy confirmed the octahedral coordination of Fe and Cr ions in the powders. XPS spectra revealed dual oxide states of Fe (Fe2+/Fe3+) and Cr (Cr3+/Cr4+) elements, and oxygen element appeared as lattice oxygen and defect oxygen, respectively. The LFCO powders exhibit ferromagnetic behavior at 5 K with saturation magnetization of 0.31 μB/f.u., coercive field of 8.0 kOe, and Curie temperature of 200 K. Griffiths phase appeared in the powders between 200 K and 223 K. The LFCO ceramics displayed a butterfly-like magnetoresistance (MR)-magnetic field (H) curve at 5 K with MR (5 K, 6 T) value of -4.07%. Temperature dependence of resistivity of the LFCO ceramics demonstrated their semiconducting nature. Electrical transport data were fitted by different conduction models. Strong frequency dispersion dielectric behavior was observed in the LFCO ceramics. A dielectric abnormality observed around 260 K, was ascribed to the jumping of electrons trapped in shallow levels created by oxygen vacancies. The dielectric relaxation behavior exhibited by dielectric loss between 160 K and 260 K, was contributed to the singly-ionized oxygen vacancies.

The definition, origin and recreation of life remain elusive. As others have suggested, only once we put life into reductionist physical terms will we be able to solve those questions. To that end, this work proposes the phenomenon of life to be the product of two dissipative mechanisms. From them, one reinterprets extant biological life and deduces a testable scenario for its origin. The proposed theory of life allows its replication, reinterprets ecological evolution, creates new constraints on the search for life and lays the foundations for groundbreaking technologies.

It is proposed that the primary living cells (“probionts”) cannot emerge of organic substance simply by continuous chemical complication of prebiotic macromolecules and microsystems. The complication must be accompanied by the radical thermodynamic transformation (“jump”) of prebiotic microsystems that resulted in the acquired ability to extract free energy from the environment and export entropy. This transformation is called “the thermodynamic inversion” The inversion may occur by means of the efficient (intensified) response of the microsystems on the oscillations of physic-chemical parameters in hydrothermal environment. In this case the surplus available free energy within a microsystem, when combined with the informational modality, facilitates its conversion into a new microsystem—a living probiont. It is shown the schematic representation of an oscillating prebiotic microsystem that is transforming into a living probiont. A new kind of laboratory and computational experiments on prebiotic chemistry under oscillating conditions is offered to verify the inversion concept.

The ultramafic-hosted Kairei vent field, located at 25°19′S, 70°02′E towards the northern end of the segment 1 of the Central Indian Ridge (CIR-S1) in a water depth of ~2450 m. This study aims to investigate the distribution of trace elements among sulfides of differing textures, and discuss the possible factors controlling the trace element distribution in those minerals by using LA-ICP-MS spot analyses as well as line scans. Our results show that there are distinct systematic trace element distributions throughout the different minerals：(1) Pyrite is divided into three types at the Kairei, including early-stage euhedral pyrites (py-I), sub-euhedral pyrites (py-II), and colloform pyrites (py-III). Pyrite is generally enriched in Mo, Au, As, Tl, Mn, and U. py-I have higher contents of Se, Te, Bi, and Ni, py-II are enriched in Au relative to py-I and py-III, but poor in Ni, py-III are enriched in Mo, Pb, and U but are poor in Se, Te, Bi, and Au. Variations in the concentrations of Se, Te, and Bi in pyrite are likely governed by the strong temperature gradient. Ni is generally lower than Co in pyrites, indicates that our samples precipitated at a high-temperature condition, whereas the extreme Co enrichment is likely from a magmatic heat source combined serpentinization reactions underlie the deposits. (2) Chalcopyrite is characterized by high concentrations of Co, Se, Te. The abundant of Se and Te in chalcopyrite cause by the high solubilities of Se and Te incorporated into chalcopyrite lattice at high temperature fluids. The concentration of Sb, As and Au is relatively low in chalcopyrite from the Kairei vent field. (3) Sphalerite from both the Zn-rich chimney is characterized by high concentrations of Sn, Co, Ga, Ge, Ag, Pb, Sb, As, and Cd, but depleted in Se, Te, Bi, Mo, Au, Ni, Tl, Mn, Ba, V, and U in comparison with the other minerals. The high concentration of Cd and Co is likely caused by the substitution of Cd2+ and Co2+ for Zn2+ in sphalerite. A high concentration of Pb accompanied by high Ag concentration in sphalerite indicating the Ag occurs in the microinclusions of Pb-bearing minerals such as galena. Au is generally low in sphalerite and strong correlate with Pb suggesting its presence in the microinclusions of galena. The strong correlation of As with Ge in sphalerite from Kairei suggests that they might precipitate under medium- to low-temperature with moderately reduced conditions. (4) Bornite-digenite is very low in most trace elements, except for Co, Se, and Bi. The high concentration of Se and Bi in all the sulfide minerals was observed in bornite-digenite can be explained by abundant Bi-selenide inclusions. Serpentinization in ultramafic-hosted hydrothermal systems might play an important role on Au enrichment in pyrite with low As contents. Compared with felsic-hosted seafloor massive sulfide (SMS) deposits, sulfide minerals from the ultramafic-hosted deposits show higher concentrations of Se and Te, but lower As, Sb, and Au concentrations attributed to the contribution of magmatic volatile input. Significant Se enrichment in chalcopyrite has been found from mafic-hosted SMSs indicate that the primary factor that controls the Se enrichment is its temperature-controlled mobility in fluids.

Economic development and population growth lead to increased production of chicken manure (CM), which is a problematic organic waste for its amount, environmental threats, and moisture content. There are different ways of CM, namely anaerobic digestion, composting, combustion, and direct land spreading. Hydrothermal carbonization (HTC) is another emerging way, however. In this study, the HTC of CM was performed to produce energy-rich material called hydrochar (HC). The effects of HTC temperature (180, 240, 300 C) and process time (30, 90, 180 min) were summarized. Proximate and ultimate analysis, as well as heating values (HHV, LHV), have been performed both on raw CM and derived HC. Additionally, the process performance has been examined. The obtained results show that HTC is a feasible method for CM disposal and valorization. Although process time did not influence considerably fuel properties of CM, higher temperature led to significantly higher HHV, reaching 23,880.6734.56 Jg-1 at 300 C and 180 min with an improvement of 8,329 Jg-1 compared with raw CM (15,551.67 Jg-1). The process conducted at 240 C in 30 min has been specified as the most favorable, due to the highest energy gain of HC and relatively low energy consumption.

The proof-of-the-concept of application of low-temperature food waste biochars for the anaerobic digestion (AD) of food waste (the same substrate) was tested. The concept assumes that residual heat from biogas utilization may be reused for biochar production. Four low-temperature biochars produced under two pyrolytic temperatures 300 °C and 400 °C and under atmospheric and 15 bars pressure with 60 minutes retention time were used. Additionally, the biochar produced during hydrothermal carbonization (HTC) was tested. The work studied the effect of a low biochar dose (0.05 gBC x gTSsubstrate-1, or 0.65 gBC x L-1) on AD batch reactors’ performance. The biochemical methane potential test took 21 days and the process kinetics using the first-order model were determined. The results showed that biochars obtained under 400°C with atmospheric pressure and under HTC conditions improve methane yield by 3.6%. It has been revealed that thermochemical pressure influences the electrical conductivity of biochars. The biomethane was produced with a rate (k) of 0.24 d-1, and the most effective biochars increased the biodegradability of FW to 81% in comparison to variants without biochars (75%).

Fluorescent carbon dots (C-dots) were synthesized by one pot hydrothermal treatment of garlic juice at 180 °C for 7h. The as-prepared C-dots with an average diameter of 2.13±0.71 nm can be well dispersed, and show absinthe fluorescence with a quantum yield of 8.9% in water. The C-dots were fully characterized by TEM, XPS, XRD, and FTIR, respectively. Additionally, the as-prepared C-dots reveal nearly nontoxic to SW480 cells and can be used for cell imaging. The water solution of C-dots show sensitivity to pH values and metal ions, and also have a high selectivity to the Hg²⁺ ion among other transition metal ions, and achieve a high sensitive detection with the detection limit of 0.45 μM. The fluorescent C-dots are expected to be useful for the evaluation of mercury ions in environmental water system.

A novel experimental technique, quasi-equilibrated temperature-programmed desorption and adsorption (QE-TPDA) was used to study the water sorption properties and hydrothermal stability of aluminum trimesate MIL-96 and aluminum isophthalate CAU-10, which have been selected due to their remarkable sorption properties. The QE-TPDA profiles of water observed for MIL-96 and CAU-10 confirmed the hydrophilic nature of these materials. Complex QE-TPDA profiles indicate that water sorption in MIL-96 follows a three-step pore filling mechanism. The shape of single desorption peaks in the QE-TPDA profiles for CAU-10 confirms that water sorption involves a reversible phase transition. Based on the QE-TPDA profiles, the water adsorption heat were determined: 45-46 kJ/mol for CAU-10 and 43-56 kJ/mol for MIL-96, in the latter case depending on the adsorption extent. Hydrothermal stability tests revealed that MIL-96 retained its stable porosity-related sorption capacity for water after hydrothermal treatment up to 290°C. Gradual changes in the QE-TPDA profiles due to the hydrothermal treatment above 290°C, with decreasing the high-temperature desorption peak and increasing the low-temperature one, indicate minor structural changes occurring in this material. Only after 410° C treatment was fast degradation of MIL-96 observed. CAU-10 exhibited high and unchanged hydrothermal stability up to 400°C.

Peroxydisulfate activation has garnered a lot of interest due to its benefits of broad adaptability, strong anti-interference ability, and powerful oxidation capacity. Due to their low cost and potent action, carbon materials are new green catalysts that have garnered interest. In order to effectively degrade organic contaminants in water by activating peroxydisulfate, carbon compounds are currently commonly used. Better metal ions for activating peroxydisulfate include Fe2+ and Co2+, and these metal ions can be encapsulated in carbon compounds made by calcinating metal organic framework（MOFs ）as precursors. The synthesis of carbon compounds from MOF precursors as well as their effectiveness and mechanism in reducing organic pollutants in peroxydisulfate systems. The following are the specific research contents: NH2-MIL-101 (Fe/Co) bimetallic MOFs material was synthesized by hydrothermally altering the Fe3+ to Co2+ ratio, followed by the carbonization of Fe/Co-CNs. XRD, SEM, TEM, FT-IR, and XPS were used to analyze the materials' morphology, structure, and chemical make-up. The results demonstrate that Fe/Co-CNs-2 (Co2+ doping concentration approaches 20%) has a stable three-dimensional carbon structure and effectively incorporated Co ions into the carbon material. The simultaneous encapsulation of both Fe and Co metals by the three-dimensional carbon skeleton ensures material stability and reaction activity. Tetracycline hydrochloride was reported to degrade more quickly in Fe/Co-CNs-2 than in other Co2+ doping concentrations within 30 minutes of peroxymonosulfate（PMS） activation. The degradation rate of Fe/Co-CNs-2 for 20 mg/L TC was determined to be 93.34% within 30 minutes under the following conditions: Fe/Co-CNs-2 concentration of 0.1 g/L, PMS concentration of 0.2 g/L, and pH of 7.33. The catalyst also demonstrates good stability. Last but not least, the Fe/Co-CNs-2 free radical quenching experiment revealed that singlet oxygen (1O2) is the primary active species in the reaction system, and a potential mechanism was examined by combining degradation and XPS analysis.

The ridge-furrow plastic mulching (RFPM) system and nitrogen application have been effective strategies for improving crop productivity in the Loess Plateau of China. However, it is not clear how the ridge-furrow ratio and nitrogen fertilizer type (NT) affect the utilization of water, nitrogen, heat and radiation resources for increased rain-fed wheat production. Two nitrogen fertilizer types [Traditional urea (TU) and controlled-release urea (CRU)] and four planting patterns [conventional flat planting (F) and the RFPM system of 20 cm ridge with 40 cm furrow (R2F4), 40 cm ridge with 40 cm furrow (R4F4), and 60 cm ridge with 40 cm furrow (R6F4)] were tested from September, 2018 to June, 2021 during winter wheat growing season. The results showed that the RFPM system can increase the soil thermal time (TTsoil) by 41.0–152.1°C d compared to F. The thermal effect of the RFPM system shortens the vegetative growth period and extends the reproductive growth period by 2–7 days, promoting the increase of the leaf area index (LAI) and final dry matter (DM) accumulation. These significantly increased the grain yield (GY) in the RFPM system by 51.6–115.2% and enhanced the thermal time use efficiency (TUE) by 48–99.5%, water productivity (WP) by 37.4–76.3%, radiation use efficiency (RUE) by 16.3–34.4%, and partial factor productivity of nitrogen (PFPN) by 51.6–115.2% compared to F. Although a high ridge-furrow ratio combined with CRU increased GY and resources use efficiency, it also exacerbated the soil water depletion, especially in the 40–140 cm soil layer. Overall, applying CRU in combination with the RFPM system of 40 cm ridge with 40 cm furrow maximized resources use efficiency and increased wheat production in the Loess Plateau of China.

This work aims to investigate systematically the influence of process temperature, bio-mass-to-water ratio, and production scales (laboratory and pilot) on the chemical composition of aqueous and gaseous phases and mass production of chemical by hydrothermal processing of Açaí (Euterpe Oleraceae, Mart.) seeds. The hydrothermal carbonization carried out at 175, 200, 225, and 250 °C, 2 °C/min, biomass-to-water ratio of 1:10, and at 250 °C, 2 °C/min, and biomass-to-water ratios of 1:10, 1:15, and 1:20, in technical scale, as well as at 200, 225, and 250 °C, 2 °C/min, bio-mass-to-water ratio of 1:10, in laboratory scale. The elemental composition (C, H, N, S) of solid phase determined to compute the HHV. The chemical composition of aqueous phase determined by GC and HPLC and the volumetric composition of gaseous phase by using an infrared gas an-alyzer. For the experiments in pilot scale with constant biomass-to-water ratio of 1:10, the yields of solid, liquid, and gaseous phases varied between 53.39 and 37.01% (wt.), 46.61 and 59.19% (wt.), and 0.00 and 3.80% (wt.), respectively. The yield of solids shows a smooth exponential de-cay with temperature, while that of liquid and gaseous phases a smooth growth. By varying the biomass-to-water ratios, the yields of solid, liquid, and gaseous reaction products varied be-tween 53.39 and 32.09% (wt.), 46.61 and 67.28% (wt.), and 0.00 and 0.634% (wt.), respectively. The yield of solids decreases exponentially with increasing water-to-biomass ratio and that of liquid phase increases in a sigmoid fashion. For constant biomass-to-water ratio, the concentrations of Furfural and HMF decrease drastically with increasing temperature, reaching a minimum at 250 °C, while that of phenols increases. In addition, the concentrations of CH3COOH and total car-boxylic acids increase, reaching a maximum at 250 °C. For constant process temperature, the concentrations of aromatics vary smoothly with the temperature. The concentrations of furfural, HMF, and cathecol decrease with temperature, while that of phenols increases. The concentra-tions of CH3COOH and total carboxylic acids decrease exponentially with temperature. Finally, for the experiments with varying water-to-biomass ratios, the productions of chemicals (furfu-ral, HMF, phenols, cathecol, and acetic acid) in the aqueous phase is highly dependent on the biomass-to-water ratio. For the experiments in laboratory scale with constant biomass-to-water ratio of 1:10, the yields of solid ranged between 55.9 and 51.1% (wt.), showing not only a linear decay with tem-perature, but also a lower degradation grade. The chemical composition of main organic compounds (furfu-ral, HMF, phenols, cathecol, and acetic acid) dissolved in the aqueous phase in laboratory scale shows the same behavior of those in obtained in pilot scale.

This work aims to investigate systematically the influence of process temperature and biomass-to-water ration on the chemical composition of aqueous and gaseous phases and mass production of chemical by hydrothermal processing of Açaí (Euterpe Oleraceae, Mart.) seeds. The hydrothermal carbonization carried out at 175, 200, 225, and 250 °C, 2 °C/min, biomass-to-water ratio of 1:10, and at 250 °C, 2 °C/min, and biomass-to-water ratios of 1:10, 1:15, and 1:20, in technical scale. The chemical composition of aqueous phase determined by GC and HPLC and the volumetric composition of gaseous phase by using an infrared gas analyzer. For constant biomass-to-water ratio of 1:10, the yields of solid, liquid, and gaseous phases varied between 53.39 and 37.01% (wt.), 46.61 and 59.19% (wt.), and 0.00 and 3.80% (wt.), respectively. The yield of solids shows a smooth exponential decay with temperature, while that of liquid and gaseous phases a smooth growth. By variation of biomass-to-water ratios, the yields of solid, liquid, and gaseous reaction products varied between 53.39 and 32.09% (wt.), 46.61 and 67.28% (wt.), and 0.00 and 0.634% (wt.), respectively. The yield of solids decreases exponentially with increasing water-to-biomass ratio and that of liquid phase increases in a sigmoid fashion. For constant biomass-to-water ratio, the concentrations of Furfural and HMF decrease drastically with temperature, reaching a minimum at 250 °C, while that of phenols increases. In addition, the concentrations of CH3COOH and total carboxylic acids increase, reaching a maximum at 250 °C. For constant process temperature, the concentrations of aromatics vary smoothly with the temperature. The concentrations of furfural, HMF, and cathecol decrease with temperature, while that of phenols increases. The concentrations of CH3COOH and total carboxylic acids decrease exponentially with temperature. Finally, for the experiments with varying water-to-biomass ratios, the productions of chemicals (furfural, HMF, phenols, cathecol, and acetic acid) in the aqueous phase is highly dependent on the biomass-to-water ratio.

Reducing CO2 emissions is urgently needed to slow down the impacts of climate change. CO2 capture using an amine solution has been developed and implemented on pilot and commercial scales. However, amine scrubbing, in particular, produces a lot of degraded solvent as waste and is energy intensive. Solid sorbents have been called to overcome those drawbacks. In this work, waste biomass-derived carbon materials were developed and tested for CO2 capture and conversion. Advanced thermal chemical processes i.e. hydrothermal and pyrolysis were applied to produce materials from agri-food waste such as soybean and okara. It was found that the number of functional groups (-C=O and -OH) in activated carbon appears in the synthesized materials, implying the generation of surface oxygenated groups. Preliminary results showed that the synthesized activated carbons are obtained with good yields, and a relatively high surface area, which may be applied as CO2 adsorption materials to solve the CO2 emission problems.

A hydrothermal technique with microwave heating (200 °C, 2 hours, 2 magnetrons, 2.45 GHz) was modified to obtain UV-C luminescent LaPO4: Pr3+ colloidal nanorods for the potential use in X-ray cancer theranostics. For further possible biofunctionalization, a compound of tartaric acid formed under basic conditions was used as a coating and stabilizing agent to provide colloidal properties to the surface of nanoparticles in basic to neutral aqueous media, which was confirmed by zeta potential measurements. In addition, the colloidal properties and clustering processes of synthesized LaPO4:Pr3+ nanorods in aqueous solutions with different pH values were studied in real time using a highly sensitive laser ultramicroscope operating according to the “light-sheet” scheme. A comparative analysis of the transmission electron microscopy, X-ray powder diffraction and high-energy spectroscopy showed the different effects of synthesis parameters on the morphological, crystalline and luminescent properties of the obtained nanorods. Through optimization of the synthesis parameters, stable aqueous solutions of m-LaPO4:Pr3+ nanorods with sizes less than 30 nm and an intensity of UV-C luminescence equal to 5-10% of the unmodified nanofibers were obtained.

Li₂TiO₃ nanopowders were synthesized by hydrothermal process using anatase TiO₂ and LiOH H₂O as raw materials. Li₂TiO₃ crystallizes in the layered monoclinic structure (space group C2/c) with average crystallite size of 34 nm. Morphology, elemental composition and local structure of products were carried out using HRTEM, FESEM, EDS, Raman and FTIR spectroscopy. Transport properties investigated by d.c. (4-probe measurements) and a.c. (complex impedance spectroscopy) show the activation energy of 0.71 and 0.65 eV, respectively. The ionic transport properties of Li⁺ ions in nanocrystalline Li₂TiO₃ characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) validate the good electrochemical properties of this anode material for lithium-ion batteries.

The storage of biochemical information, which is a prerequisite for the development of the first cell, is an unsolved problem affecting all concepts of the origin of life. However, if the protected environment in the continental crust is taken into account, completely new possibilities emerge for identifying processes that may have been crucial for the formation of the first cell. Under this background, we can hypothesize that cellular life began, with a self-sustaining cycle of molecular reaction steps and information storage of peptide sequences in RNA in a crustal depth of approximately 1000 m. This cycle was made possible in an open system bound to gas-permeable tectonic fracture zones with a high proportion of CO₂ and/or N₂. It can be assumed that a large number of RNA-like molecular strands formed in the crustal environment, from which a special RNA was selected by flotation processes, which formed the basis of a proto-tRNA. The formation of peptides and vesicles in supercritical CO₂ and the chemical evolution of peptides have already been proven at conditions of the upper continental crust. The behavior of individual amino acids in connection with vesicle formation deserves special interest. Hydrophobic amino acids accumulate in the vesicle membrane, with their position in the membrane depending on the degree of hydrophobicity. Selection of a proto-tRNA with an acceptor arm ending with the bases CCA resulted in a distinctive property. The position of adenine at the tip of the acceptor arm permitted it to penetrate the membrane, allowing it to be linked to an amino acid at the 3'-OH position of the terminal ribose. The penetration depth was controlled by the hydrophobicity of the opposite anti-codon, with adenine always occupying the middle position for the hydrothermally formed hydrophobic amino acids. When the vesicle membrane was closely occupied by proto-tRNAs, the anti-codons acted as templates and stored the sequence of the peptides that form. In the cases of hydrophilic anti-codons, the acceptor arm does not reach far enough into the membrane. This allowed hydrophilic amino acids to be linked to 2´-OH.

To obtain drop-in fuel properties from non-feed biomass, we herein report the catalytic hydrotreatment of microalgae biocrude, produced from hydrothermal liquefaction (HTL) of Spirulina. Our contribution focuses on the effect of temperature, initial H2 pressure, and residence time on the removal of heteroatoms (O and N). In contrast to common hydrotreating experimental protocols at batch scale, we devised a set of two-level factorial experiments and studied the most influential parameters affecting the removal of heteroatoms. It was found that up to 350 °C, the degree of deoxygenation (de-O) is mainly driven by temperature, whereas the degree of denitrogenation (de-N) also relies on initial H2 pressure and temperature-pressure interaction.Based on this, complete deoxygenation was obtained at mild operating conditions (350 °C), reaching a concurrent 47 % denitrogenation. Moreover, three optimized experiments are reported with 100 % removal of oxygen. In addition, the analysis by GC-MS and Sim-Dis gives insight to the fuel quality. The distribution of heteroatom N in lower (<340 °C) and higher (>340 °C) fractional cuts is studied by a fractional distillation unit following ASTM D-1160. Final results show that 63-68 % of nitrogen is concentrated in higher fractional cuts.

Nanomaterials based on metal oxides (MexOy) are employed as catalysts and/or sorbents in processes undergoing conditions in supercritical water (scH2O), the “green” reaction medium used to obtain energy relevant products. Their properties are greatly affected by the synthesis method used to produce the active MexOy. Moreover, in order to maintain their performance, it is more practical and cost-effective to use supported MexOy nanoparticles. Within this context, the present work deals with the preparation of carbon-supported ZnO and CuO composites by an innovative method based on impregnation under scH2O conditions. Metal oxides were impregnated on a carbon (C) support using a continuous flow tubular reactor. The results show that impregnation in scH2O is a promising approach for the preparation of ZnO/C and CuO/C composite materials. This one-step synthesis method, in a continuous flow, uses neither seed layer nor mineralizer, and it needs substantially lower preparation times than the conventional impregnation methods.

In this work, we report on the first attempt using size-controlled ZnO nanoparticles (NPs) to analyze role of thioacetamide (TAA) in forming ZnS nanostructures from ZnO. The size-controlled B(blue)_, G(green)_, Y(yellow)_ZnO QDs, and NC (nanocrystalline)_ZnO NPs were synthesized by sol-gel process as well as hydrothermal method, respectively and then reacted with an ethanolic TAA solution as sulfur source. After reacting with TAA, the formation of ZnS QDs was observed over time. The chemical reactions were identified using X-ray diffraction (XRD), Transmission Electron Microscope (TEM), UV-vis spectroscopy, and Photoluminescence (PL). All results indicate that ZnS formation is due to direct crystal growth and/or chemical conversion of ZnO to ZnS. Our results enable a broader understanding of the synthetic mechanisms involved in the use of TAA as a sulfur source in forming ZnS nanostructures from ZnO.

There is great importance and need of improving existing carbon materials fabrication methods. As such, this work proposes to discuss, interrogate, and propose viable hydrothermal, solvothermal, and other advanced carbon materials synthetic methods. The advanced carbon materials to be interrogated will include the synthesis of carbon dots, carbon nanotubes, nitrogen/titania-doped carbons, graphene quantum dots, and their nanocomposites with solid/polymeric/metal oxide supports. This will be done with special mind to microwave-assisted solvothermal and hydrothermal synthesis due to their favourable properties such as rapidity, low cost, and green/environmentally-friendliness. Thus, these methods are important during the current and future synthesis and modification of advanced carbon materials for application in energy, gas separation, sensing, and water treatment. Simultaneously, the work will pay special cognizance to methods reducing the fabrication costs and environmental impact while enhancing the properties as a direct result of the synthesis methods. As a direct result, the expectation is to impart a significant contribution to the scientific body of work regarding the improvement of the said fabrication methods.

Temperature differences between the atmosphere and river water allow rivers to be used as a hydrothermal energy source. The river-water heat pump system is a relatively non-invasive renewable energy source; however, effluent discharged from the heat pump can cause downstream temperature changes which may impact sensitive fluvial ecosystems. In this study, the water temperature recovery distance of the effluent was estimated for a river section in the Han River Basin, Korea, using the heat transfer equation and the Environmental Fluid Dynamic Code (EFDC) model. Results showed that, compared to the EFDC model, the heat transfer equation tended to overestimate the water temperature recovery distance due to its simplified assumptions. The water temperature recovery distance could also be used as an objective indicator to decide the reuse of downstream river water. Furthermore, as the river system was found to support an endangered fish species that is sensitive to water environment changes, care should be taken to exclude the habitats of protected species affected by water temperatures within water temperature recovery distance.

Zinc cobalt oxide-zinc hydroxide (ZnCo2O4-Zn(OH)2) microspheres were successfully fabricated on carbon cloth via a sample hydrothermal method. The surface morphology of these microspheres and their efficacy in degrading methyl violet were further modulated by varying the thermal annealing temperatures. The manipulation of thermal annealing temperatures was pivotal in adjusting the porosity of ZnCo2O4-Zn(OH)2 microspheres to amplify their photocatalytic performance. Various analytical techniques were utilized to evaluate the physical and chemical properties of the ZnCo2O4-Zn(OH)2 microspheres, including field-emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, field-emission transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis spectroscopy. Compared to untreated ZnCo2O4-Zn(OH)2 microspheres, those subjected to thermal annealing exhibited increased specific surface area and light absorption capacity, rendering them highly effective photocatalysts under UVC light exposure. Subsequent studies have confirmed the superior performance of ZnCo2O4-Zn(OH)2 microspheres as a reusable photocatalyst for degrading methyl violet and tetracycline. Additionally, trapping experiments during the photodegradation process involving ZnCo2O4-Zn(OH)2 microspheres have identified hydroxyl radicals (·OH) and superoxide radicals (·O2–) as the primary reactive species.

In this study, unlike conventional methods for producing vanadium (3.5+) electrolyte by VOSO4 and V2O5, a batch-type hydrothermal reactor was used to produce a vanadium (3.5+) electrolyte for vanadium redox flow batteries through a reduction reaction. The starting material, V2O5, was mixed with different concentrations of citric acid (0.8M, 1.2M, 1.6M, 2.0M) as reducing agent and stirred using a hot plate at 90°C for 60 minutes to achieve complete dispersion in the solution. The resulting solution was then subjected to a hydrothermal reduction reaction in a furnace at 150°C for 24 hours to produce vanadium (3.5+). The mixed state of the produced vanadium (3+) and vanadium (4+) was confirmed using UV-vis spectroscopy. Electrochemical properties were investigated through CV analysis, confirming that the optimal concentration was 1.6M. Charge and discharge experiments were conducted to compare the current efficiency, energy efficiency, and voltage efficiency of the electrolyte prepared by the hydrothermal reduction process and the electrolyte prepared by VOSO4. As a result, the electrolyte produced through the hydrothermal reduction process showed improved performance in all efficiencies. The results shows that vanadium (3.5+) electrolyte could be easily produced through a reaction process using citric acid.

The main objective of this communication is to describe the ‘Global Salt Cycle’. Giant salt accumulations are commonly found along continental margins of former rifts. The first stage in the accumulation process is saturation of newly formed oceanic crust with seawater. Final mobilisation and accumulation of the salts occurs during rifting, localised in the vicinity of relict subduction zones. Oceanic crust is created along the spreading ridges in the deep oceans of the Earth. It exchanges mass and energy with seawater in hydrothermal circulation cells that penetrate deep into the new and fractured crust. Water-rock interactions include the formation of hydrated and hydroxylated minerals, e.g., serpentinites and clay minerals. By incorporating hydroxyl groups and water in their crystal lattices, the salinity of remaining brines increases. Subduction of oceanic crust and serpentinised lithosphere transports water, hydrated minerals, and marine salts deep into the crust and mantle. Upon pressurisation and heating of the subducting slab, different parts of this water are expelled at different depths/temperatures. The resulting fluids will contain salts brought in with the slab, as well as new salts formed by water-rock interaction. The combination of elevated pressures and temperatures, water, salinity, and CO2, create permeability in the normally impermeable, peridotitic mantle, by altering the fluid-rock dihedral angles of mineral grains. This P/T-determined intergranular permeability allows ascent of saline fluids, under lithostatic pressure, within the mantle wedge, or the slab itself. The fluids produce a mechanically weakened and buoyant zone within the mantle wedge due to high pore pressure between mineral grains and reduced mantle density. During the lifetime of a subduction zone, a substantial accumulation of saline fluids within the mantle wedge and crust, is evident. Deep, fluid reservoirs accumulate between the subduction trench and the volcanic front. They may exist for hundreds of millions of years, even after the extinction of the subduction zone. Saline fluids may escape to the surface along deep faults, due to overfilling of available pores/fractures. Fluids within the mantle wedge may form rock melts or exist as supercritical, mineral rich fluids. The combination of reduced pressure due to rifting, and a saline and buoyant mantle, creates a mantle circulation that brings the accumulated, saline fluids, to crustal levels. Salts will therefore accumulate during initial stages of rifting as a result of massive fluid expulsion, phase change and boiling of mantle fluids. No extra energy is required to produce phase change and boiling. The result is formation of solid salts or dense brines/slurries invading fractured crustal rocks, or escaping to the surface/seabed. This process may take place both before and after the sea has invaded a continental rift.