The design of processing routes involving the presence of the liquid phase is mainly associated with the knowledge of its surface and transport properties. Despite this need, due to experimental difficulties related to high temperature measurements of metallic melts, for many alloy systems neither thermodynamic nor thermophysical properties data are available. A good example lacking these datasets represents the Ir-Si system, although over the last fifty years, the structures and properties of its solid phases have been widely investigated. To compensate the missing data, the Gibbs free energy of mixing of the Ir-Si liquid phase was calculated combining the model predicted values for the enthalpy and entropy of mixing using Miedema’s model and Free Volume Theory, respectively. Subsequently, in the framework of statistical mechanics and thermodynamics, the surface properties were calculated using the Quasi Chemical Approximation (QCA) for the regular solution, while to obtain the viscosity, the Moelwyn-Hughes (MH) and Terzieff models were applied. Subsequently, the predicted values of the abovementioned thermophysical properties were used to model the non-reactive infiltration isotherm of Ir-Si (eutectic) / SiC system.

Traditional refractory materials such as nickel-based superalloys have been gradually unable to meet the performance requirements of advanced materials. The Mo-Si-based alloy, as a new type of high temperature structural material, has entered the vision of researchers due to its charming high temperature performance characteristics. However, its easy oxidation and even "pesting oxidation" at medium temperatures limit its further applications. In order to solve this problem, researchers have conducted large numbers of experiments and made breakthrough achievements. Based on these research results, the effects of rare earth elements like La, Hf, Ce and Y on the microstructure and oxidation behavior of Mo-Si-based alloys were systematically reviewed in the current work. Meanwhile, this paper also provided an analysis about the strengthening mechanism of rare earth elements on the oxidation behavior for Mo-Si-based alloys after discussing the oxidation process. Furthermore, the research focus about the oxidation protection of Mo-Si-based alloys in the future was prospected to expand the application field.

In laser joining of copper (Cu) and aluminum (Al) sheets, the Al sheet is widely chosen as the top surface for laser irradiation because of increased absorption of laser beam and lower melting temperature of Al in contrast to Cu. This research focus on welding from Cu side to Al sheet. The main objective of irradiating the laser beam from the copper side (Cu on top) is to exploit higher solubility of Al in Cu. A significantly lower laser power can be used with 515 nm laser in comparison to 1030 nm. In addition to low laser power, a stable welding is obtained with 515 nm. Because of this advantage, 515 nm is selected for the current research. By fusion of Cu and Al the two sheet metals are welded, with presence of beneficial Cu solid solution phase and Al+Al2Cu in the joint with the brittle phases intermixed between the ductile phase. Therefore the mixed composition strengthens the joint. However excessive mixing leads to formation of more detrimental phases and less ductile phases. Therefore optimum mixing must be maintained. Energy dispersive X-ray spectroscopy (EDS) analysis indicate that large amount of beneficial Cu solid solution and Al rich phases is formed in the strong joint. From the tensile shear test for a strong joint, fracture is obtained on the heat-affected zone (HAZ) of Al. Therefore the key for welding from copper side is to have optimum melt with beneficial phases like Cu and Al+ Al2Cu and the detrimental phases intermixed between the ductile phases

Understanding of the decisive role of the interaction mechanism and kinetics in the combustion processes is highly relevant for the elaboration of optimal conditions for obtaining Mo-Cu composite powders. From this perspective, the efficient delivery of the reduction mechanism of copper and molybdenum oxides with combined Mg + C reducing agents at high heating rates is crucial to develop a valuable approach for the combustion synthesis of Mo-Cu composite powders. Herein, we shed light on the mechanism of the reactions in all the studied binary, ternary and quaternary systems contemporaneously demonstrating the effect of the heating rate on the conversion degree. The combination of two highly exothermic and speedy reactions (MoO3+3Mg and CuO+Mg vs MoO3+CuO+4Mg) led to a slow interaction with weak self-heating (dysynergistic effect) due to a change in the reaction mechanism. On the other hand, it has been shown that during the simultaneous utilization of the Mg and C reducing agents, the process begins exclusively with carbothermic reduction, and at relatively high temperatures it continues with magnesiothermic one. The effective activation energy values of the magnesiothermic stages of the studied reactions were determined by Kissinger isoconversional method.

PHLNs (polymeric lipid hybrid nanoparticles) are core–shell nanoparticle structures made up of polymer cores and lipid shells that have properties similar to both polymeric nanoparticles and liposomes. Methotrexate (MTX) loaded PLHNPs containing tween 80, phosphatidylcholine, poly D, L-lactic-co-glycolic acid (PLGA) & glyceryl tripalmitate prepared using solvent injection & homogenization method for glioblastoma treatment option. The MTX loaded PLHNPs optimized by Box–Behnken design to minimize particle size, higher entrapment efficacy, and maximize MTX concentration in the brain at 4h. The particle size, entrapment efficacy, concentration of drug in brain at 4h, zeta potential and AUC(Brain)/AUC(Plasma) ratio were in the range of 173.51-233.37nm, 70.56-86.34%, 6.38-12.38 μg/mL, 25.78-36.31mV & 1.02-5.32. in-vitro drug release studies, cellular internalization of optimized formulation against U-87 MG shows good anticancer effects.

Objectives: Multicentric Osteolysis, Nodulosis, and Arthropathy (MONA) syndrome is a rare genetic skeletal dysplasia. Its diagnosis can be deceptively similar to childhood-onset genetic skeletal dysplasias and juvenile idiopathic arthritis. We aimed to report the syndrome’s clinical and radiologic features with emphasis on skeletal manifestations. And establish relevant phenotype-genotype correlations. Methods: We evaluated two boys, 4-and-7-years-old with MONA syndrome. Both patients had consanguineous parents. We verified the diagnosis by correlating the outcomes of clinical, radiologic and molecular analysis. We specifically evaluated the craniofacial morphology and clinical and radiographic skeletal abnormalities. We contextualized the resultant phenotype-genotype correlations to publications on MONA and its differential diagnosis. Results: Skeletal manifestations were the presenting symptoms and mostly restricted to hands and feet in terms of fixed extension deformity of the metacarpophalangeal and flexion deformity of the interphalangeal joints with extension deformity of big toes. There were arthritic symptoms in the older patient especially of the wrists and minute pathologic fractures. The skeletal radiographs showed osteopenia/dysplastic changes of hands and feet. Both patients had variants in the matrix metalloproteinase2 gene which conformed to phenotype of previously reported literature in one patient while the other had a novel variant which conformed to MONA phenotype. Craniofacial abnormalities were present. However, minimal extra-skeletal manifestations. Conclusion: Overall, there is an emerging distinctive skeletal pattern of involvement in terms of both clinical and radiographic features. This includes age of onset and location of presenting skeletal manifestations, chronological order of joint affection, longitudinal disease progression, specifics of skeletal radiographic pathology and craniofacial features. Nevertheless, physicians are cautioned against differential diagnosis of similar genetic skeletal dysplasias and juvenile idiopathic arthritis.

To enhance the mechanical properties (i.e. strength and elongation) of the face-centered cubic (fcc) α-phase in the Au-Cu-Al system, this study focused on the introduction of the martensite phase (doubled B19 (DB19) crystal structure of Au2CuAl) via the manipulation of alloy compositions. Fundamental evaluations, such as microstructure observations, phase identifications, thermal analysis, tensile behavior examinations, and reflectance analysis have been conducted. The presence of fcc annealing twins was both observed in the optical microscope (OM) and the scanning electron microscope (SEM) images. Both the strength and elongation of the alloys were greatly promoted while the DB19 martensite phase was introduced into the alloys. Amongst all the prepared specimens, the 47Au41Cu12Al and the 44Au44Cu12Al alloys performed the optimized mechanical properties. The enhancement of strength and ductility in these 2 alloys was achieved while the stress plateau was observed during the tensile deformation. A plot of the ultimate tensile strength (UTS) against fracture strain was constructed to illustrate the effects of the introduction of the DB19 martensite phase on the mechanical properties of the alloys. Regardless of the manipulation of the alloy compositions and the introduction of the DB19 martensite phase, the reflectance stayed almost identical to pure Au.

The drought is one of all phenomena at local to a global scale that caused climate change impacts, alongside it also the human activities related, which were deforested and land use changed that caused to ecological disturbance, which one is hydrological changes. Hence, it’s a lot of lost productivity, chiefly to farming land aspects and the other, so the land restoration by reforestation is needed in framework to water cycle (hydrology) process kindly. The aim of this research has identified and analyzed ecological restoration to ecosystem services, chiefly in wastewater management (treatment) to conservation, especially in Al Zaytun areas (Pesantren), so observing and in-depth individual interview (with some of personage and pesantren of boards) is one method that used to data collected, alongside land survey management to classified type development in Al Zaytun areas. The result of this research revealed that Al Zaytun successfully in water management to conservation by wastewater treated management by Eichhornia crassipes (Enceng gondok), afterward to the reservoir as water saved development. Those conservation types considered capability in reviving to ecological systems to ecosystem services increased kindly, alongside to land restoration by some of the plant species or trees to grow and developed in which Tectona grandis L. f is more dominantly and it's favorite because of investment economic that advantage based on ecological perspective. These were type management that did by Al Zaytun, alongside its able in coping to both drought and climate change impacts kindly and adaptively, and of course, it’s part of an obligation as the follower’s Islam religion in preserving and maintaining natural resources, chiefly to water resources.

Intermetallic alloys like e.g. Iron-Aluminides, Titanium-Aluminides or Molybdenum- Silizides are prospective materials for high-temperature applications. For additive manufacturing (AM) intermetallic structural materials are particularly challenging due to their high melting points, oxygen susceptibility and low temperature brittleness. The feasibility of manufacturing intermetallic Mo-Si-B alloys with the laser additive manufacturing process of direct energy deposition (DED) is demonstrated and recent results in characterizing rapidly solidified material with respect to correlations between process, composition and microstructures are presented. The possibility to dope the material with Yttrium oxide (Y2O3) for dispersion is successfully demonstrated. Current challenges, e.g. homogenous distribution of alloying elements and applicability are addressed.

In this work, effects of 20 transition element additives on the interfacial adhesion energy and electronic structure of Al (111)/6H-SiC (0001) interfaces have been studied by first principles method. For clean Al (111)/6H–SiC (0001) interfaces, both Si-terminated and C-terminated interfaces have covalent bond characteristics. The C-terminated interface has stronger binding energy, which is mainly due to the stronger covalent bond formed by the larger charge transfer between C and Al. The results show that the introduction of many transition elements, such as 3d transitional group Mn, Fe, Co, Ni, Cu, Zn and 4d transitional group Tc, Ru, Rh, Pd, Ag, can improve the interfacial adhesion energy of the Si-terminated Al (111)/6H-SiC (0001) interface. However, for the C-terminated Al (111)/6H-SiC (0001) interface, only the addition of Co element can improve the interfacial adhesion energy. Bader charge analysis shows that the increase of interfacial binding energy is mainly attributed to more charge transfer.

Bacterial internalization is a strategy that non-intracellular microorganisms use to escape the host immune system and survive inside the human body. Among bacteria species, Staphylococcus aureus showed ability to interact and infect osteoblasts causing osteomyelitis as well as bone and joint infection, while also becoming increasingly resistant to antibiotic therapy and a reservoir of bacteria that can make the infection difficult to cure. Despite being a serious issue in orthopedic surgery, little is known about the mechanisms that allow bacteria to enter and survive inside the osteoblasts, also due to the lack of consistent experimental models. In this review, we describe the current knowledge about S. aureus internalization mechanisms and various aspects of the interaction between bacteria and osteoblasts (e.g. best experimental conditions, bacteria-induced damages and immune system response), focusing on studies performed using the MG-63 osteoblastic cell line, so far the best model for the study of this phenomenon.

Nano Silicon carbide reinforced aluminum (Al/nanoSiC) metal matrix composites are attractive because of their superior properties such as high strength and stiffness, Application of aluminum in technological and structural application is growing steadily. The major limitation for metal matrix nano composites, however, is their propensity to brittle fracture. The new technologies and new materials are two basic aims for companies. In this research, the effect of addition Al/SiC nano particles on microstructure and mechanical properties of pure aluminum has been investigated. Pure aluminum powder and various fractions of SiC particles with an average diameter of 50 nm were milled by a high-energy planetary ball mill to produce nanocrystalline Al–SiC nanocomposite powders. Pressing and sintering applied to consolidate powders to tablet shape. Then the samples were rolled to cylindrical shape. The nano SiC Percentage were 0%, 2.5%, 5%, 7.5%, 10% , 12,5% and 15%. Mechanical tests such as tensile, hardness, fracture toughness and young’s modules measurement carried out to study the mechanical behavior of each alloy. Scanning electron microscopy was used to study the morphology and microstructure of nanocomposite powders and bulk samples. The role of wt% fraction of SiC nanoparticles was investigated. The results shows that the addition of SiC nano particles has significant influence on the microstructure and mechanical properties of composites and usually the optimum properties depends on wt% SiC.

The narrow process window during intercritical annealing and discontinuous yielding have limited the commercialisation of medium Mn steels. In this study, a double annealing process based on the commercial continuous annealing line is proposed. The cold-rolled medium Mn steels were first fully austenitized and quenched during the first annealing, followed by the intercritical annealing for reverted austenite transformation. The microstructure of duplex lath-shaped austenite and ferrite is produced and the steel exhibit a desirable continuous yielding during tensile deformation. Al is added into the medium Mn steel to enlarge the process window and to improve partitioning efficiency of Mn. The produced steel is more robust with temperature fluctuation during the industrial process due to the enlarged intercritical region. Mn partitioning is more efficient owing to elevated annealing temperature, which results in the improvement of ductility in the Al-added steel with increased austenite stability.

Planktonic foraminiferal biomineralization intensity, reflected by their shell calcite mass, affects global carbonate deposition and is known to follow the climate cycles by being increased during glacial stages and decreased during interglacial ones. Here we measure the dissolution state and the mass of the shells of the planktonic foraminifera species Globigerina bulloides from a Tropical Eastern North Atlantic site over the last two glacial-interglacial climatic transitions and we report no major changes in plankton calcite production with the atmospheric pCO2 variations. We attribute this consistency in foraminifera calcification to the climatic and hydrological stability of the tropical regions. We however recorded increased shell masses midway through the penultimate deglaciation (Termination II). In order to elucidate the cause of the increased shell weights we performed δ18O, Mg/Ca and μCT measurements on the same shells from a number of samples surrounding this event. We find that shells of increased mass are internally contaminated by sediment infilling and that shell weights are responding to local hydrographic changes.

This paper reports on the fabrication of alumina doped preforms using MCVD-vapor phase chelate delivery system with Al(acac)3 as the precursor. The objectives of the work are to study the deposition process, the efficiency of the fabrication process, and the quality of the fabricated fiber preforms. Two parameters are studied, Al(acac)3 sublimator temperature (TAl°C) and deposition direction (i.e. downstream and upstream). Other parameters such as oxygen flow and deposition temperature are fixed. The results showed that a high uniformity of refractive index difference (%RSD < 2%) and core size (%RSD < 2.4%) was obtained along the preform length using downstream deposition while for the combined upstream and downstream deposition the uniformity was deteriorated. The process efficiency was found to be about 21% for TAl°C of 185°C and downstream deposition. From the EDX elemental analysis, the refractive index was found to increase by 0.0025 per mole percent of alumina.

The effect of retrogression re-aging treatment (RRA) on corrosion behavior of 7055 Al-Zn-Mg alloy were studied. Results provides the corrosion resistance could be greatly improved by RRA. After the RRA treatment, the isolated precipitates occurred on grain boundaries (GBs) and the low angle grain boundaries (LAGBs) presented a larger fraction compared to the single-stage peaking aging. The samples after RRA treatment also show better corrosion resistance than the single-stage peak aging. The results of electrochemical impedance spectroscopy (EIS) show that impedance spectrum is consisted of semi-infinite layer diffusion impedance and stagnant Weber impedance. The semi-infinite layer diffusion impedance corresponded a limited retention layer on the electrode surface. In corrosion process, Weber impedance corresponded to stagnant layer of corrosion products generated by the anode branches. The RRA sample has the high Rf and low Cf, Cp values, and the corrosion current density of the RRA samples is ten times less than the single-stage peak aging samples with the 10% hardness losing.

The poor oxidation resistance of refractory high-entropy alloys (RHEAs) is a major obstacle for their use in high-temperature engineering applications. Anti-oxidation coating technology is an effective method for improving the oxidation resistance. In this paper, the Si-20Cr-20Fe coating was prepared on MoNbTaTiW RHEA by a fused slurry method. The microstructural evolution and compositions of the silicide coating under high-temperature oxidation environment were studied. The results show that the silicide coating could effectively prevent the oxidation of the MoNbTaTiW RHEA. The initial silicide coating had a double-layer structure; a high silicon-content layer mainly composed of MSi2 as the outer layer and a low silicon-content layer mainly contained M5Si3 as the inner layer. Under high-temperature oxidation conditions, the silicon element diffused from the silicide coating to the RHEA substrate while the oxidation of the coating occurred. After oxidation, the coating was composed of an outer oxide layer and an inner silicide layer. The silicide layer moved toward the inside of the substrate, led to the increase of its thickness. Compared with the initial silicified layer, its structure did not change significantly. The structure and compositions of the oxide layer on the outer surface strongly depended on the oxidation temperature. This paper provides a strategy for protecting RHEAs from oxidation at high-temperature environments.

In this paper, 6063 aluminum alloy for common building profiles is used as the research object. By adding a new Al-Ti-C-La composite alloy, the effect of 6063 aluminum alloy on the microstructure and properties of 6063 aluminum alloy is studied. The results show that Al-Ti-C-La composite alloy has obvious effect on grain refinement of 6063 aluminum alloy. With the addition of Al-Ti-C-La composite alloy, the grain size decreased significantly. When the addition amount of Al-Ti-C-La composite alloy is 1%, the grain size is reduced from 482 μm to 121 μm. Rare earth La is mainly distributed near the Mg2Si phase and β-AlFeSi, and complex compounds such as AlFeSiMgLa are formed. After aging for 270 days on the basis of T6 heat treatment, the tensile strength and elongation of 6063 aluminum alloy augmented with the addition of Al-Ti-C-La composite alloy, and the Vickers hardness gradually diminished. When the addition amount of Al-Ti-C-La composite alloy is 1%, the tensile strength, elongation and Vickers hardness of 6063 aluminum alloy reach 177.2 MPa, 17.8% and 60.9 HV, respectively, and the tensile strength is increased by 16.3%. The elongation is increased by 50.8%, the Vickers hardness is reduced by 15.4%, and the fracture of the alloy is mainly ductile fracture.

The present overview of spin-dependent phenomena in nonmagnetic semiconductor microparticles (MPs) and nanoparticles (NPs) with interacting nuclear and electron spins is aimed at covering a gap between the basic properties of spin behavior in solid-state systems and a tremendous growth of the experimental results on biomedical applications of those particles. The first part of the review represents modern achievements of spin-dependent phenomena in the bulk semiconductors from the theory of optical spin orientation under indirect optical injection of carriers and spins in the bulk crystalline silicon (c-Si) – via numerous insightful findings in the realm of characterization and control through the spin polarization – to the design and verification of nuclear spin hyperpolarization in semiconductor MPs and NPs for magnetic resonance imaging (MRI) diagnostics. The second part of the review is focused on the electron spin-dependent phenomena in Si-based nanostructures, including the photosensitized generation of singlet oxygen in porous Si and design of Si NPs with unpaired electron spins as prospective contrast agents in MRI. The experimental results are analyzed by considering both the quantum mechanical approach and several phenomenological models for the spin behavior in semiconductor/molecular systems. Advancements and perspectives of the biomedical applications of spin-dependent properties of Si NPs for diagnostics and therapy of cancer are discussed.

The fabrication and characterisation of photo-anodes based on black-Si (b-Si) are presented using a photo-electrochemical cell in NaOH solution. Black-Si was fabricated by maskless dry plasma etching and was conformally coated by tens-of-nm of TiO2 using atomic layer deposition (ALD) with a top layer of CoO_x cocatalyst deposited by pulsed laser deposition (PLD). Low reflectivity R < % of Black-Si over the entire visible and near-IR (λ < 2 µm) spectral range is favourable in better absorption of light while an increased surface area facilities larger current densities. Photoelectrochemical performance of the heterostructured photoanode is discussed in terms of n-n junction between b-Si and TiO₂.

The outdoor field test of the 4-terminal on Si tandem photovoltaic module (specifically, InGaP/GaAs on Si) was investigated and performance model, considering spectrum change affected by fluctuation of atmospheric parameters, was developed and validated. The 4-terminal on Si tandem photovoltaic module had about 40 % advantage in seasonal performance loss compared with standard InGaP/GaAs/InGaAs 2-terminal tandem photovoltaic module. This advantage is expanded in (subarctic zone) < (temperate zone) < (subtropical zone). The developed and validated model used all-climate spectrum model and considered fluctuation of atmospheric parameters, and can be applied every type of on-Si tandem solar cells.

Climate change and environmental degradation are major threats to sustainable agricultural development in Southern Africa. Thus, the concept of sustainable intensification (SI) i.e. getting more output from less input using certain practices such as agroforestry, organic fertilizer, sustainable water management etc. has become an important topic among researchers and policy makers in the region in the last three decades. A comprehensive review of literatures on the adoption of SI in the region identify nine relevant drivers of adoption of SI among (smallholder) farmers. These drivers include (i) age, (ii) size of arable land, (iii) education, (iv) extension services, (v) gender, (vi) household size, (vii) income, (viii) membership in farming organization and (ix) access to credit. We present the results of a meta-analysis of 21 papers on the impact of these determinants on SI adoption among (smallholder) farmers in Southern African Development Community (SADC) using random-effects estimation techniques for the true effect size. While our result suggests that variables such as extension services, education, age, and household size may influence the adoption of SI in SADC, factors such as access to credit is also of great importance. Decision-makers should therefore concentrate efforts on these factors in promoting SI across the SADC. This includes increasing the efficiency of public extension service as well as involvement of private sector in extension service. Furthermore, both public and private agriculture financing models should consider sustainability indicators in their assessment process.

The microstructures and mechanical properties of the hot-rolled Fe-6.5wt.%Si sheet are analyzed. The microstructure of the hot-rolled sheet is layered along the thickness direction. The surface exhibits fine and equiaxed grains, whereas the center part shows coarse and elongated grains with a <101> fiber texture along the rolling direction. Serrated flow behavior is observed during tensile deformation of both the hot-rolled sheet and its center samples at 350 °C; thus, the serrated flow of the hot-rolled sheet is mainly attributed to the serration of the center part. The analyses of dislocation configurations, ordered structures, and crystal orientation show that the serrated flow behavior results from the interaction of solutes with mobile dislocations. Mobile dislocations are pinned by combining parallel forest dislocations with the pipe diffusion of solution atoms. This study provides a new perspective for the deformation mechanism of the Fe-6.5wt.%Si alloy.

Recently, the environment is being put under constantly increasing pressure. Globally, water shortage is considered as one of the most serious environmental problems which affect human life and plant wealth. Iraq is highly affected by water deficit in many regions. In particular, Al-Najaf region is selected to be under evaluation for the current and future water resources shortage. This study is based on the collected data for rainfall, evaporation, flow-rate, groundwater, water needed for irrigation, and daily uses for the period between 2000 and 2018. The Artificial Neural Network, normal distribution, and lognormal distribution type III are applied for analyzing the collected data in addition to predict the water shortage for year 2050. Results show a water shortage in years 2002, 2004, 2005, and 2017 only for the selected period. A Simulink model is constructed using Matlab to increase the credibility of the estimated results and gives accurate results for the groundwater and surface water needed. Where in 2050, it is found that it needs to use the groundwater source by 0.024 x 10⁹ m³ to support the surface water source which is represented by the Euphrates River. The study shows the extent of inefficient management of water resources in Al-Najaf region.

The area of Central and Eastern Europe, and thus Poland, is not exposed to effects of seismic actions. Any possible tremors can be caused by coal or copper mining. Wind, rheological effects, the impact of other objects or a non-uniform substrate are the predominant types of loading included in calculations for stiffening walls. The majority of buildings in Poland, as in most other European countries, are low, medium-high brick buildings. Some traditional materials, like solid brick (>10% of construction materials market) are still used. But autoclaved aerated concrete (AAC) and cement-sand calcium-silicate (Ca-Si) elements with thin joints are prevailing (>70% of the market) on the Polish market. Adding reinforcement only to bed joints in a wall is a satisfactory solution (in addition to confining) for seismic actions occurring in Poland that improves ULS and SLS. This paper presents results from our own tests on testing horizontal shear walls without reinforcement and with different types of reinforcement. This discussion includes 51 walls made of solid brick (CB) reinforced with steel bars and steel trusses, results from tests on 15 walls made of calcium-silicate (Ca-Si) and AAC masonry units reinforced with steel trusses and plastic meshes. Taking into account our own tests and those conducted by other authors, empirical relationships were determined on the basis of more than 90 walls. They are applicable to design and construction phase to determine the likely effect of reinforcement on cracking stress that damage shear deformation and wall stiffness.

The electrical and optical properties of sol-gel derived aluminum-doped0 zinc oxide thin films containing 2 at.% Al were investigated considering the modifying effects of 1) increasing the sol H₂O content; and 2) thermal treatment procedure with high-temperature approach followed by an additional heat-treatment step under a reducing atmosphere. According to the results obtained via the TG-DTA analysis, FT-IR spectroscopy, X-ray diffraction technique and four-point probe resistivity measurement, it is argued that the sol hydrolysis, decomposition of the deposited gel and crystallization of grains result in grains of larger crystallite size and stronger c-axis preferred orientation with slightly less microstrain in the modified sample. The consequent morphology and grain-boundary characteristics turn out as improved conductivity, implying higher values of concentration and mobility of charge carriers. A detailed investigation on samples optical properties, in terms of analyzing their absorption and dispersion behaviors through the UV-Vis-NIR spectroscopy, support our reasoning for the increase of the mobility, and to a lesser extent, the concentration of charge carriers, while causing only a slight degradation of optical transmission. Hence, an enhanced performance as a transparent conducting film is claimed for the modified sample by comparing the figure-of-merit values.

A detailed analysis of the dehydrogenation mechanism and reversibility of LiBH₄ doped by active Al* derived from AlH₃ was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD), scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the dehydrogenation of LiBH₄/Al* is a five-step reaction: (1) LiBH₄ + Al → LiH + AlB₂ + “Li-Al-B-H” + B₂H₆ + H₂; (2) the decomposition of "Li-Al-B-H" compounds liberating H₂; (3) 2LiBH₄ + Al → 2LiH + AlB₂ + 3H₂; (4) LiBH₄ → LiH + B + 3/2H₂; (5) LiH + Al → LiAl + 1/2H₂. And the reversibility of LiBH₄/Al* composite is based on equation as follows: LiH + LiAl + AlB₂ + 7/2H₂ ↔ 2LiBH₄ + 2Al. The extent of dehydrogenation reaction between LiBH₄ and Al* greatly depends on the precipitation and growth of reaction products (LiH, AlB₂ and LiAl, etc.) on the surface of Al*. A passivation shell of Al* formed by these products is the kinetic barrier to the dehydrogenation of LiBH₄/Al* composite.

According to research, we have learned that Mg and TiO2 are new types material of marine protective coatings. We found that the addition of Mg can improve the performance of Zn-Al coating passivation film, and TiO2 has excellent photocatalytic self-cleaning performance. In this paper Zn-Al pseudo alloy coating was prepared by cold spray technique, and Zn-Al-Mg-TiO2 pseudo alloy composite coating was prepared by adding Mg and nano-TiO2. The effects of Mg and TiO2 to the marine protective properties of Zn-Al coatings were studied by friction and wear test, dynamic salt water corrosion test, electrochemical test, scanning electron microscope(SEM), energy dispersive spectrometer(EDS) and super deep scene 3D microscope. The results show that the addition of Mg and nano-TiO2 not only fills the gap of the coating and improves the density of the coating, but also generates grid-like flocculent corrosion products on the surface of the coating which can gather other corrosion products to improve the density of corrosion products, reduce the friction coefficient and corrosion rate of the coating surface, effectively prevent the invasion of Cl- in solution, and improve the wear and corrosion resistance of the coating.

Two novel core-shell composites SiO2@PMDA-Si-Tb, SiO2@PMDA-Si-Tb-phen with SiO2 as the core and terbium organic complex as the shell, were successfully synthesized. The terbium ion was coordinated with organic ligand forming terbium organic complex in the shell layer. The bi-functional organosilane ((HOOC)2C6H2(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as PMDA-Si) was used as the first ligand and phen as the second ligand. Furthermore, the silica-modified SiO2@PMDA-Si-Tb@SiO2, SiO2@PMDA-Si-Tb-phen@SiO2 core-shell-shell composites were also synthesized by sol–gel chemical route. An amorphous silica shell was coated around the SiO2@PMDA-Si-Tb and SiO2@PMDA-Si-Tb-phen core-shell composites. The core-shell and core-shell-shell composites both exhibited excellent luminescence in solid state. The luminescence of core-shell-shell composites was stronger than that of core-shell composites. Meanwhile, an improved luminescence stability property for the core-shell-shell composites was found in the aqueous solution. The core-shell-shell composites exhibited bright luminescence, high stability, long lifetime, and good solubility, which may present potential applications in the field of bio-medical.

Seeds represent the major source of food protein, impacting on both human nutrition and animal feeding. Therefore, seed quality needs to be appropriately addressed in the context of viability and food safety. Indeed, long-term and inappropriate storage of seeds might result in enhancement of protein glycation, which might affect their quality and longevity. Glycation of seed proteins can be probed by exhaustive acid hydrolysis and quantification of the glycation adduct N^ɛ-(carboxymethyl)lysine (CML) by liquid chromatography-mass spectrometry (LC-MS). This approach, however, does not allow analysis of thermally and chemically labile glycation adducts, like glyoxal-, methylglyoxal- and 3-deoxyglucosone-derived hydroimidazolones. Although enzymatic hydrolysis might be a good solution in this context, it requires aqueous conditions, which cannot ensure reconstitution of seed protein isolates. Because of this, the complete profiles of seed AGEs are not characterized so far. Therefore, here we propose the approach, giving access to quantitative solubilization of seed proteins in presence of sodium dodecyl sulfate (SDS) and their quantitative enzymatic hydrolysis prior to removal of SDS by reversed phase solid phase extraction (RP-SPE). Using MG-H1 as a case example, we demonstrate the applicability of this method for reliable and sensitive LC-MS-based quantification of chemically labile AGEs and its compatibility with bioassays.

Power semiconductor devices are essential from the operation point of view, size, efficiency and cost, these components are used in a myriad of applications, providing features that make them an important part of the system in which they are operating. This document analyzes and compares the basic structure, properties, design aspects, as well as temperature performance, stability and switching losses, present in devices on silicon (Si), silicon carbide (SiC) and new generation devices fabricated in gallium nitride (GaN) applied in renewable energy systems. The main objective is determinate the viability of the new generation components, which present a superior performance in view of an increase in efficiency, conductivity, decreases in switching losses, lower resistances and parasitic capacitances as well as higher operating frequency range. Therefore demonstrating the GaN components are a strong and viable candidate to solve some of the problems present in renewable energy systems.

A series of defective ZSM-5 zeolites (~300 nm, SiO₂/Al₂O₃ ratio of 55, 100, 400 and 950) were intentionally prepared and systematically studied by XRD, SEM, ²⁹Si MAS NMR, argon physisorption, NH₃-TPD and FT-IR technologies. The nature, the amount and the accessibility of the acid sites of defective ZSM-5 zeolites are greatly different from reported ZSM-5 zeolites with perfect crystal structure. The co-existed strong Brønsted acid sites (Si(OH)Al) and weak Brønsted acid sites (hydroxyl nests) over defective ZSM-5 zeolites might lead to unique catalytic function. Zn(C₂H₅)₂ was grafted onto defective ZSM-5 zeolites through chemical liquid deposition (CLD) method. Interestingly, FT-IR spectroscopy studies find that Zn(C₂H₅)₂ was preferentially grafted on the hydroxyl nests with weak acidity rather than the Si(OH)Al groups with strong acidity over different defective ZSM-5 zeolites. Particularly, home-built operando dual beam FTIR-MS was applied to study the catalytic performance of Zn species locating at different sites of defective ZSM-5 zeolites under n-hexane transformation. Results show that Zn species grafted over hydroxyl nests obtain better dehydrogenation performance than Zn species over framework aluminum. This study provides guidance for the rational design of highly efficient alkane dehydrogenative aromatization catalysts.

The microstructure of Al-5Fe-1.5Er alloy was characterized and analyzed by using XRD, SEM, TEM and EDS. The effect of microstructure on the behavior of crack initiation and propagation was investigated by in situ tensile testing. Results show that the microstructure consists of α-Al matrix, Al₃Fe, Al₄Er, eutectic phase Al₃Fe + Al₄Er, while the 1.5 wt.% Er was added in Al-5Fe alloy. The twin structure of the Al₃Fe phase was observed, and the twin plane is {001}. Moreover, a continuous concave and convex interface structure of the Al₄Er has been found. Al₃Fe is in the form of a sheet with a clear gap inside.In situ tensile tests of the alloy at room temperature show that the crack initiation occured mainly in the Al₃Fe phase, and that the crack propagation modes include intergranular and transgranular expansion. Crack transgranular expansion is due to the strong binding ability between Al₄Er phases and surrounding organization, and the continuous concave and convex interface structure of the Al₄Er provides a significant meshing effect on the matrix and eutectic structure.

In this study, Li-Al-OH layered double hydroxide (LDH), which was prepared by solvent-free one-step mechanochemical reaction of LiOH and Al(OH)₃, was applied to remove boron from aqueous solution. Dry-grinding for 3 h at a rotational speed of 500 rpm, Li/Al molar 1/2 was the optimum condition to prepare highly crystalline of Li-Al LDH phase with no evident impure phases. Two milling products with Li/Al molar ratio at 1/2 and 2/2 were evaluated for boron adsorption. The results confirmed that Li/Al molar ratio 2/2 sample showed high boron adsorption capacity due to the physical adsorption of Li-Al-OH LDH and chemical synergism of phase gel Al(OH)₃. The adsorption isotherms, described by the Langmuir model, indicated maximum monolayer boron uptake capacity 45.45 mg/g, implying competitive adsorption capacity of the material in our experiment.

Carbonate precipitation induced by microorganism has become a hot spot in the field of carbonate sedimentology, while the effect of different magnesium on biominerals has rarely been studied. Therefore, magnesium sulfate and magnesium chloride were used to investigate the significant role played on carbonate minerals. In this study, Staphylococcus epidermidis Y2 was isolated and identified by 16S rDNA homology comparison. The ammonia, pH, carbonic anhydrase, carbonate and bicarbonate ions were investigated. The mineral phase, morphology and elemental composition were analyzed by XRD and SEM-EDS. The ultrathin slices of bacteria were analyzed by HRTEM-SAED and STEM. The result showed that this bacterium could release ammonia and carbonic anhydrase to increase pH, and elevate the supersaturation via a large number of carbonate and bicarbonate ions released through carbon dioxide hydration catalyzed by carbonic anhydrase. The crystal cell density of monohydrocalcite was lower in magnesium chloride medium than that in magnesium sulfate medium. The crystal grew in a mode of spiral staircas in magnesium sulfate medium, while in a concentric circular pattern in magnesium chloride medium. There was no obvious intracellular biomineralization. This study may be helpful to further understand the biomineralization mechanism, may also provide some references for the reconstruction of paleogeological environment.

We report the effects of surface passivation by depositing a hydrogenated amorphous silicon (a-Si:H) layer on the electrical characteristics of low temperature polycrystalline silicon thin film transistors (LTPS TFTs). The a-Si:H layer was optimized by hydrogen dilution and its structural and electrical characteristics were investigated. The a-Si:H layer in the transition region between a-Si:H and µc-Si:H resulted in superior device characteristics. Using an a-Si:H passivation layer, the field-effect mobility of the LTPS TFT was increased by 78.4% compared with a conventional LTPS TFT. Moreover, the leakage current measured at a V_GS of 5 V was suppressed because the defect sites at the poly-Si grain boundaries were well passivated. Our passivation layer, which allows thorough control of the crystallinity and passivation-quality, should be considered a candidate for high performance LTPS TFTs.

Compressive residual stresses in thin films can inhibit crack propagation under normal or sliding contact loading, with associated enhancement of the coating apparent toughness, load bearing capacity and wear resistance. This study investigates the influence of residual stress distributions on the thin film/substrate adhesion using a nanoindenter coupled with scanning electron microscope (SEM) investigations of indentation induced failure modes. Reactive and un-reactive magnetron sputtering with ion plating was used to coat a (100) silicon substrate with aluminum nitride (AlN) with and without an aluminum (Al) adhesion layer. The presence of an Al bond layer gives additional interfacial tensile stress because of the difference in thermal expansion coefficient. Additionally, a different magnitude of residual stresses in the AlN coating was achieved by changing the applied bias voltage onto the substrate. Wafer curvature method and incremental focused ion beam (FIB) milling, combined with high-resolution in situ scanning electron microscopy (SEM) imaging and full field strain analysis by digital image correlation (DIC), were used to measure the average and in-depth stress residual stress distribution in the produced coatings. The adhesion energy was then quantified by using a nanoindentation based model. Results demonstrate that the additional tensile residual stress in the aluminum adhesion layer decrease significantly the coating adhesion, even in presence of a higher compressive stress state in the AlN top-layer. Therefore, the coatings without Al-layer showed better adhesion because of a more homogeneous compressive residual stress in comparison with the coating having Al layer, even though both groups of coatings are produced under same bias voltage. Results are discussed, and some general suggestions are made on the correlation between coating/substrate property combination and the adhesion energy of multilayer stacks. The results suggested that Al bond-layer and inhomogeneous residual stresses affected the adhesion of AlN negatively to a substrate like silicon.

Biomineralization has become a research hotspot and attracted widespread attention in the field of carbonate sedimentology. In this study, Bacillus licheniformis DB1-9 was used to induce the calcium carbonate precipitation at different magnesium calcium molar ratios in the laboratory to further explore the biomineralization mechanism. Phylogenetic tree shows that the bacteria belongs to Bacillus licheniformis species. The ammonia and carbonic anhydrase can be released by this bacteria, resulting in the pH increase, and the carbonic anhydrase can also promote the hydration reaction of carbon dioxide and subsequently produce the bicarbonate and carbonate ions to elevate the supersaturation of calcium carbonate in the liquid culture medium to facilitate the precipitation of carbonate minerals. The calcites have a shape of rhombohedron, dumbell, and elongation, and aragonite often appears in the form of mineral aggregates, besides that there are also the spherical and the fusiform minerals. FTIR result shows there are some organic functional groups, such as C-O-C and C=O, beside of the characteristic peaks of the calcite and the aragonite, indicating that microbial metabolism is closely related to the mineral formation. The superthin slices of the bacteria analyzed by HRTEM, SAED, EDS and STEM show that the surface and EPS can adsorb a large number of calcium ions and magnesium ions and EPS may act as the nucleation sites, what’s more, the intracellular nanometer-scale sphere areas show the amorphous structures, and the intracellular calcium ions and magnesium ions suggeste that they can be transported from the outside to inside the cell by diffusion along the concentration grade from high to low. This study may provide some references to further understand the biomineralization mechanism induced by microorganisms in the laboratory and the field, and also helps to explore the reason of the transition of calcite sea to aragonite sea in the geological history.

We investigate the ammonium removal abilities of natural and synthetic zeolites, which have distinct Si/Al ratios and various surface areas, to study how adsorption and ion-exchange processes in zeolites perform under different ammonium concentrations and different temperatures. Five zeolites including natural mordenite, chabazite, erionite, clinoptilolite and synthetic merlinoite were immersed in 20 mg/kg, 50 mg/kg and 100 mg/kg ammonium solutions. The results demonstrate that zeolites under high ammonium concentrations (100 mg/kg) possess higher physical adsorption capacity (0.398–0.468 meq/g), whereas those under lower ammonium concentrations (20 mg/kg) possess greater ion-exchange property (64–99%). The ion-exchange ability of zeolites are extremely dependent on the cation content of the zeolites, and the cation content is affected by the Si/Al ratio. The surface area of zeolites also has a partial influence on its physical adsorption ability. When the surface area is less than 100 m²/g, the adsorption ability of zeolite increases obviously with surface area; however, adsorption ability is saturated as the surface area becomes larger than this critical value of 100 m²/g. When we carried out the zeolites in 50 mg/kg ammonium concentration at different temperatures (5~50 ℃), we found that zeolites exhibit the highest ammonium removal ability at 30°C and the potassium release was enhanced at 30~40 ℃.

It is important for researchers in material domain to reconstruct and visualize the microstructure of alloy, which helps discover morphologies and properties that can only be found in three dimensional and microscopic space. However, because of the limitation of state-of-the-art sensors, the internal microstructure of the material is not easy to obtain. In this paper, a novel automatic 3D reconstruction method is proposed using diffraction contrast tomography technology to capture the 3D microstructure of Al-La alloy. The pipeline of the proposed method starts from the imaging of Al-La alloy with the LabDCT technique from Carl Zeiss AG, which produces a sequence of 2D microstructure sections. Then, a segmentation algorithm based on superpixel and lifted multicut is proposed to extract the 2D microstructure in an image section. Finally, 2D segmentations are joined together to reconstruct and visulize the 3D microstructure. As a result, a novel morphology of Al-La alloy is recovered with both dendrite and lamellar morphologies. The proposed method has the advantage of the ability to losslessly recover the internal microstructure.

Present work has systematically investigated the evolution of dispersoid and elevated-temperature properties including the strength and creep resistance during the various multi-step heat treatments in Al-Mn-Mg 3004 alloys. Results show that only α-Al(MnFe)Si dispersoid is observed in the studied temperature range (up to 625°C) and it coarsens with increasing temperature to 500°C but dissolves at 625°C. The evolution of elevated-temperature strength and creep resistance is greatly related to the temperature of each step during the multi-step heat treatments. Generally, lower temperature at the first-step heat treatment leads to higher properties while the properties decrease with increasing temperature of last-step heat treatment. Suitable models have been introduced to explain the evolution of strength and the creep threshold stress at elevated-temperature during the various heat treatments.

A series of Si-bearing MgAl₂O₄-spinels were synthesized at 1500-1650 °C and 3–6 GPa. These spinels had SiO₂ contents up to ~1.03 wt%, and showed a substitution mechanism of Si⁴⁺ + Mg²⁺ = 2Al³⁺. Unpolarized Raman spectra were collected from polished single grains, and displayed a set of well-defined Raman peaks at ~610, 823, 856 and 968 cm^-1 which had not been observed before. Aided with the Raman features of natural Si-free MgAl₂O₄-spinel, synthetic Si-free MgAl₂O₄-spinel, natural low quartz, synthetic coesite, synthetic stishovite and synthetic forsterite, we infer that these Raman peaks should belong to the SiO₄ groups. The relations between the Raman intensities and SiO₂ contents of the Si-bearing MgAl₂O₄-spinels suggest that at some P-T conditions some Si must adopt the M-site. Unlike the SiO₄ groups with very intense Raman signals, the SiO₆ groups are largely Raman-inactive. We have further found that the Si cations primarily appear on the T-site at P-T conditions ≤ ~3–4 GPa and 1500 °C, but attain a random distribution between the T-site and M-site at P-T conditions ≥ ~5–6 GPa and 1630–1650 °C. This Si-disordering process observed for the Si-bearing MgAl₂O₄-spinels hints that similar Si-disordering might happen to the (Mg,Fe)₂SiO₄-spinels (ringwoodite), the major phase in the lower part of the mantle transition zone of the Earth and the index mineral for the very strong shock stage experienced by extraterrestrial materials. The likely consequences have been explored.

In order to understand the hot deformation behavior of novel Cu/Al laminated composites, isothermal hot compression tests were conducted by Gleeble-1500D thermo-mechanical simulator. And the effect of bonding interface, deformation temperature and strain rate on the deformation behavior was analyzed. Results show that under the interface constraint effect, soft Al layer trends to flow synchronously with hard Cu layer. And further microstructure examinations indicate the cooperative deformation capability of Cu/Al composites increases with increasing stain rate and decreasing deformation temperature. Strain hardening exponent, calculated based on the true stress-true strain data, also proves the effect of deformation temperature and strain rate on the cooperative deformation behavior. Meanwhile, unique composites structure allows the Al matrix to exhibit the characteristic of dynamic recrystallization during the hot deformation process. Lastly, strain compensated Arrhenius-type constitutive equation was employed to describe the coupling effect of temperature, strain rate and strain on the flow stress.

Cylindrical Fe-6.5wt.% Si bars with 7.5 mm in diameter were successfully fabricated from as cast ingot through three rolling stages within 10 passes: rough rolling at 850–900 °C and 8–10 m/min, medium rolling at 800–850 °C and 10–15 m/min, and finish rolling at 800–850 °C and 12–18 m/min. The evolution of microstructure, texture and ordered structure, and the mechanical property are investigated. The results showed that the grains were refined by the hot bar rolling. Area fractions of the {100}<011> oriented grains and the {011}<100> oriented grains decreased to 0 during the hot bar rolling. Whereas, the {100}<001> component, the {011}<211> component and the {112}<110> component increased, and γ fiber with {111}<110> component was dominant. DO₃ ordered phase were suppressed, and B2 ordered domains were refined after the hot bar rolling. Ductility of the as rolled bar was higher than that of the rotary swaged bar, due to the absence of the DO₃ ordered phase and the fine grains in the rolled bar. Hence, the hot bar rolling technology is an excellent process to fabricate the Fe-6.5wt.% Si bars.

Ultra-thin Fe–6.5wt.%Si ribbons with 35 μm in thickness were prepared by melt-spinning. The magnetic properties were investigated before and after annealing 1000 ºC. DC properties and low-frequency (400 Hz ~ 10 kHz) iron losses have significantly improved after heat treatment. A simplified formula based on Steinmetz law which can be used to predict the AC iron loss is presented. According to the results of some iron losses data, a simplified formula has been determined, and the extent of AC iron losses can be predicted. The results obtained from the formula predict AC iron loss to a good degree. The method developed in this work could be extended to other magnetic materials for predicting AC iron loss with greater ease.

Formation of Fe- and Mg-rich smectite and zeolite under alkaline conditions is concerned as secondary minerals after alkaline alteration of bentonite in a repository of radioactive wastes. It might be crucial for safety assessment whether smectite will be formed or not as secondary minerals after alkaline alteration of bentonite. In present paper, Fe- and Mg-rich smectite which are currently interacting with hyperalkaline groundwater was found at Narra in Palawan, Philippines. Mineralogical and geochemical investigation was conducted to understand formation process of smectite and factors determined secondary mineral species. Our study revealed a certain amount of smectite may have been produced under hyperalkaline conditions, altered from amorphous or poorly crystalline material such as M-S-H and F-S-H. Key factor which decides smectite or zeolite as secondary minerals after alkaline alteration of bentonite might be whether nuclei of M-S-H and/or F-S-H will be formed or not. This might be decided by the presence of dissolved Mg2+ and Fe2+ in the system. Our suggested formation process of smectite under alkaline conditions is analogue with generally-accepted model of smectite formation that might have been occurred on early Mars.

The flow behavior of Fe-6.5wt.%Si alloys during hot compression was investigated at temperatures 650–950 °C and strain rates 0.01–10 s^-1. The results showed that the flow stress depended distinctly on the deformation temperatures and strain rates. The flow stress and work hardening rate increased with the decrease of temperature and the increase of strain rate. The activation energy under all the deformation conditions was calculated to be 410 kJ/mol. The constitutive equation with hyperbolic sine function and Zener–Hollomon parameter was developed. The peak stress, critical stress, and steady-state stress could be represented as σ=A+Bln(Z/A). Dynamic recrystallization occurred under the deformation conditions where the values of Z were lower than 10²⁰. Processing maps were established to optimize the processing parameters. The power dissipation efficiency decreased in the high temperature and low strain rate region, increased in the high temperature and high strain rate region, and remained unchanged in other regions with the increase of true strain. Furthermore, the unstable area expanded. The true strain of 0.7 was the optimum reduction according to the processing map. Based on the analysis of surface quality, microstructures, and ordered structures, the optimized processing parameters for the Fe-6.5wt.%Si alloys were the temperature and strain rate of higher than 900 °C and 0.01–10 s^-1, respectively, or 800–900 °C and lower than 0.4 s^-1, respectively.

Accurate, detailed and recent Information about land cover/use is important and much more needed for different aspects of sustainable development and environmental management. As remote sensing datasets are becomes one of the most important and effective tools to generate such information, this study aimed to generating land cover map for sub area in Al-Ahasaa Oasis, Saudi Arabia, by using and classifying a subset of Landsat-ETM+ image of the selected study area, as bases and required input for future studies and researches. Different image preprocessing techniques in addition to a will-known and widely used classification method (i.e., Maximum Likelihood classifier) were applied. To be reliable with the final product, accuracy assessment was carried out with 89% agreement and accepted according to the applied method. Different land cover classes were found in the study area, which includes (Sand dunes, Water bodies, Sabakha, Bare soil, Urban, and Agricultural lands). The study also revealed that the dominant land cover class is sand dunes with approximately ± 70% in area. The study strongly indicated that the area has long been affected by sand movement. Finally, the study suggested that, further researches with more advanced methods rather than traditional methods are needed in the future to support the findings of this study, with high degree of accuracy.

We present a general theory of estimation of analysis error covariances based on cross-validation as well as a geometric interpretation of the method. In particular we use the variance of passive observation–minus-analysis residuals and show that the true analysis error variance can be estimated, without relying on the optimality assumption. This approach is used to obtain near optimal analyses that are then used to evaluate the air quality analysis error using several different methods at active and passive observation sites. We compare the estimates according to the method of Hollingsworth-Lönnberg, Desroziers et al., a new diagnostic we developed, and the perceived analysis error computed from the analysis scheme, to conclude that, as long as the analysis is near optimal, all estimates agree within a certain error margin.

Semi-solid feedstock of AZ80 magnesium alloy modified by minor rare-earth Y element (0, 0.2, 0.4, 0.8 wt.%) were fabricated by strain induces melting activated (SIMA) in the form of extrusion and partial remelting. The effect of Y addition on the microstructure evolution of extruded and isothermal treated alloy was observed by optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD) and quantitative analysis. The results show that the Y addition can refine the microstructure and make the β-Mg17Al12 phases agglomerating. During the subsequent isothermal treatment at 570℃, the average solid grain size, shape factor and liquid fractions increased with prolonged soaking time. Smaller spheroidal solid grains and the larger shape factor were obtained due to Y addition. The coalescence and Ostwald ripening of solid grains operated the coarsening process simultaneously. The coarsening rate constants of AZ80M1 (0.2 wt.% Y addition) of 164.22 μm3s-1 was approximately four times less than the un-modified AZ80 alloy of 689.44 μm3s-1. In contrast, the desirable semi-solid structure featured by fine, well globular solid grains and appropriate liquid fractions and shape factor was achieved in AZ80M1 alloy treated at 570℃ for 20-30 min.

The mechanism underlying microbiologically induced carbonate precipitation have not been thoroughly characterized, although numerous scholars and experts have specifically investigated questions regarding minerals induced by bacteria. The study of the precipitation of carbonate minerals induced by halophilic bacteria has aroused wide concern. The present study aimed to investigate the characterization and process of biomineralization in high salt systems by a halophilic bacterium, Chromohalobacter israelensis strain LD532 (GenBank: KX766026), which was isolated from the Yinjiashan Saltern in China. Carbonate minerals induced by LD532 were investigated in several sets of comparative experiments that employed magnesium sulfate and magnesium chloride as Mg resources. Magnesium calcite and aragonite were induced by LD532 bacteria, whereas these minerals did not appear in the control group. The mineral phases, micromorphologies, and crystal structures were analysed using X-ray powder diffraction, scanning electron microscopy, and energy dispersive X-ray detection. The carbonic anhydrase and urease secreted by strain LD532 through metabolism increased the pH value of the liquid medium and promoted the process of carbonate precipitation. Further study using high resolution transmission electron microscopy, energy dispersive X-ray detection and analysis of ultrathin slices showed that the nucleation sites of carbonate minerals were located on extracellular polymeric substances and the membranes of intracellular vesicles of LD532 bacteria, which provided favourable conditions for the growth of carbonate mineral crystals. The morphologies and compositions of minerals formed in solutions of MgSO₄ and MgCl₂ display significant differences, indicating that different sources of Mg²⁺ may also affect the physiological and biochemical activities of microorganisms and thus mineral deposition. This study will be of some interest for the interpretation of carbonate biomineralization in natural salt environments and has some value as a reference in understanding sedimentary carbonates in ancient marine environments, such as tidal flats.

Aluminum base alloys containing chromium (Cr) and zinc (Zn) were produced using extrusion and heat treated powder metallurgy. Cr addition ranged between 5 to 10 wt. % while Zn was added in an amount between 0 to 20 wt. %. Heat treatment processes were performed during powder metallurgy process at different temperatures followed by water quenching. Similar alloys were extruded, with an extrusion ratio of 4.6 to get proper densification. Optical microscopy was used for microstructure investigations of the produced alloys. The element distribution microstructure study was carried out using the Energy Dispersive X-ray analysis method. Hardness and tensile properties of the investigated alloys have been examined. Wear resistance tests were carried out and the results were compared with these of the Al-based bulk alloys. Results showed that the aluminum base alloys containing 10wt. % Chromium and heat treated at 500°C for one hour followed by water quenching exhibited the highest wear resistance and better mechanical properties.

This work investigated the isothermal holding time dependence of the densification, microstructure, weight loss and tensile properties of Fe-Mn-Si powder compacts. Elemental Fe, Mn and Si powder mixtures with a nominal composition of Fe-28Mn-3Si (in weight percent) were ball milled for 5h and subsequently pressed under a uniaxial pressure of 400 MPa. The compacted Fe-Mn-Si powder mixtures were sintered at 1200 ℃ for 0, 1, 2 and 3 h, respectively. In general, the density, weight loss and tensile properties increased with the increase of isothermal holding time. A significant increase in density, weight loss and tensile properties occurred in the compacts isothermally holding for 1 h, as compared to those with no isothermal holding. However, further extension of isothermal holding time (2 and 3 h) only played a limited role in promoting the density and tensile properties. The weight loss of the sintered compacts was mianly caused by the sublimation of Mn in Mn depletion region on the surface layer of the sintered Fe-Mn-Si compacts. The length of the Mn depletion region increased as isothermal holding time increased. A single α-Fe phase was detected on the surface of all the sintered compacts, and the locations beyond the Mn depletion region were comprised of a dual dominant γ-austenite and minor ε-martensite.

The present work investigates primarily the morphology evolution of the body-centered-cubic (BCC)/B2 phases in AlxNiCoFeCr high-entropy alloys (HEAs) with increasing Al content, which has been neglected so far. There exist two types of microscopic morphologies of BCC and B2 phases in this HEA series: one is the weave-like morphology induced by the spinodal decomposition, and the other is the microstructure of a spherical disordered BCC precipitation on the ordered B2 matrix that appears in HEAs with a much higher Al content. The shape of coherent precipitates is found to be closely related to the lattice misfit between BCC and B2 phases, which is sensitive to Al. The mechanical properties, including the compressive yielding strength and microhardness of the AlxNiCoFeCr HEAs, are also discussed in light of the concept of the valence electron concentration (VEC).

Aluminum wire is a common material for wire bonding due to its resistance to oxidation and low price. It does not melt when becoming a free air ball (FAB) during the electronic flame-off (EFO) process with wettability, and is applied by wedge bonding. This study used 20μm Zn-Coated Al-0.5wt.%Si (ZAS) wires to improve the FAB shape after the EFO process, while maintaining stability of the mechanical properties, including the interface bonding strength and hardness. In order to test circuit stability after ball bonding, the current-tensile test was performed. During the experiment, it was found that 80nm ZAS with wire bonding has lower resistance and higher fusing current. For the bias tensile test, the thicker Zn film diffused into the Al-Si matrix easily, after which the strength was reduced. The ball-bond interfaces had no change in their condition before and after the bias. Accordingly, ZAS could be a promising candidate for ball bonding in the future.