Although 7055 aluminum alloy is a deformed aluminum alloy and will show excellent mechanical properties after recrystallization after large deformation, it is a method to enrich its application range if rare earth is added and the rare earth phase dispersion is promoted by heat treatment. This article used optical microscopy, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), micro Vickers hardness and room temperature stretching methods to study the as-cast 7055-xEr (x=0wt.%, 0.2wt.%, 0.4wt.%, 0.6wt.%, 0.8wt.%) aluminum alloy after being subjected to 460 oC×3h homogenization and 410 oC×1h solid solution+150 oC×12h aging treatment the changes in microstructure and properties. The results indicated that: when 0.2wt.%Er was added to 7055 aluminum alloy after solution at 410 oC×1h and aging at 150 oC×12h, the dendrite structure was significantly reduced, the grain thinning was obvious and the distribution was uniform, Al8Cu4Er phase appeared in the lamellar eutectic η-Mg(Zn,Al,Cu)2 structure at grain boundaries, and the hardness reached 168.8HV. The yield strength, tensile strength and elongation were 542.12Mpa, 577.67MPa and 8.36%, respectively.

This paper begins with an introduction to porcelain tiles. A review of the major scientific and technological features of the mullite−based porcelain tile (MPT) and anorthite−based porcelain tile (APT), focusing primarily on the raw material, processing, phase evolution and mechanical behavior, is then presented. Based on the porcelain tile firing behavior and a series of physical and chemical changes that can occur, a comprehensive comparison is described. In the last part, the prospects for further developments related to MPT and APT are discussed.

Polyethylene terephthalate (PET) is nowadays one of the most used polymers for packaging applications. Modifications induced by service conditions and the optimal mean to recycle this matter several times have to be perfectly understood to allow a reuse for similar application (from bottle to bottle for example). The present study aims to compare physico-chemical properties, crystalline organization, and mechanical behaviour of virgin (vPET) and recycled PET (rPET). Using different combined experimental methods (Calorimetry, Small Angle X-ray Scattering, Atomic Force Microscopy, DMA, and uni-axial tensile test), it has been proven that even if there is no change in the crystallinity of PET, the crystallisation process shows some differences (size and number of spherulites). The potential impact of these differences on local mechanical characterization, at the lamella scale, is explored and tends to demonstrate the development of homogeneous microstructure, leading to well-controlled and relevant local mechanical properties. This approach increases the understanding of crystallisation of PET and recycled PET during forming processes such as thermoforming or injection stretch blow moulding (ISBM) where elongation at break can depend on the microstructure conditioned by the crystallisation process.

Advanced Nano structural hard coatings are thin materials films that range in thickness from a few nanometers to a few micrometers and are applied to different surfaces to increase their hardness and wear resistance. Physical vapor deposition (PVD) or chemical vapor deposition (CVD) methods are frequently used to deposit these coatings. These coating’s distinctive characteristics result from their microstructure, which is made up of material columns or grains with a diameter of only a few nanometers. Increased hardness, higher wear resistance, and improved tribological properties result from these short dimensions. In applications with significant wear and/or high contact pressures, such as cutting tools, bearings, and engine parts, the usage of sophisticated Nano structural hard coatings is crucial. Advanced Nano structural hard coatings include, 1. Amorphous carbon coatings with high hardness, low friction, and exceptional wear resistance are known as diamond-like carbon (DLC) coatings. DLC coatings are frequently used in a variety of industries, including the automotive, aerospace, and biomedical ones. 2. Coatings made of titanium nitride (TiN): These metallic coatings have high hardness and wear resistance. Cutting tool, machining, and aerospace industries frequently use TiN coatings. 3. Chromium nitride (CrN) coatings: These coatings have great corrosion resistance, good wear resistance, and high hardness. Cutting tools, gears, and bearings are just a few of the objects that use CrN coatings. 4. Tungsten carbide (WC) coatings: These coatings, which have a high degree of hardness and wear resistance, are frequently employed in cutting tools and other applications that require wear resistance. Advanced Nano structural hard coatings provide many advantages over conventional coatings, including better hardness, increased wear resistance, and improved tribological qualities. The automotive, aerospace, and biomedical industries are just a few that could use these coatings. In this paper the author will explain about the design synthesis and applications of advanced Nano structural hard coating in aerospace and automotive applications.

Two-dimensional (2D) materials have been a research hot topic in the passed decades due to their unique and fascinating properties. Among them, mechanical properties plays an important role for their application. However, there lacks an effective tool for high-throughput calculating, analysing and visualizing the mechanical properties of 2D materials. In this work, we present, mech2d package, a highly automated toolkit for calculating and analysing second-order elastic constants (SOECs) tensor and relevant properties of 2D materials with considering their symmetry. In the mech2d, the SOECs can be fitted by both strain-energy and stress-strain approach, where the energy or strain can be calculated by first-principles engine, such as VASP. As a key feature, the mech2d package can automatically submit and collect the tasks from local or remote machine with robust fault-tolerant ability, make it suitable for high-throughput calculation. The present code has been validated by several common 2D materials, including graphene, black phosphorene, GeSe2 and so on.

Ventilation in prone position (PP) for 12 to 16 hours per day improves survival in ARDS. However, the optimal duration of the intervention is unknown. We performed a prospective observational study to compare the efficacy and safety of a prolonged PP protocol with conventional prone ventilation in COVID-19-associated ARDS. Prone position was undertaken if P/F <150 with FiO2>0.6 and PEEP>10cmH2O. Oxygenation parameters and respiratory mechanics were recorded before the first PP cycle, at the end of PP cycle and 4 hours after supination. We included 63 consecutive intubated patients with mean age 63.5 years. Of them, 37 (58.7%) underwent prolonged prone position (PPP group) and 26 (41.3%) standard prone position (SPP group). Median cycle duration for SPP group was 20 hrs and for PPP group 46 hrs (p<0.001). No significant differences in oxygenation, respiratory mechanics, number of PP cycles and rate of complications were observed between groups. The 28-day survival was 78.4% in the PPP group versus 65.4% in the SPP group (p=0.253). Extending the duration of PP was as safe and efficacious as conventional PP, but did not confer any survival benefit in a cohort of patients with severe ARDS due to COVID-19.

In this study, cement is used as the component that provides the stabilizing effect in order to evaluate the hardness and stability of loess soil. To assess the strength characteristics of loess soil reinforced with cement, samples were created with four different cement contents and three different curing times. The materials were put through a series of tests to determine their flexural strength, direct shear strength, indirect tensile strength, and unconfined compressive strength. An appropriate cement dosage was found, in addition to a durability index that could be used to quantify the effect of water absorption investigations on cement-stabilized loess. Both of these discoveries were made simultaneously. Analyses of investigations such as scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence spectrometry (XRF) examinations were carried out so that the fundamental mechanics of the materials could be comprehended. According to the findings, the cohesion of cement-stabilized loess is significantly more sensitive to structure than the friction angle of the material, and the cohesion is responsible for the increase in shear strength after remolding. To get the desired level of strength, it is necessary to adjust the cement's proportions. In addition, as the curing period progresses, we see an increase in the cement-stabilized loess's resistance and stiffness. This is because of the interactions that take place between the structure and the mineral composition. It is believed that this event was caused by the cementation that occurs naturally. As a consequence of this reaction, the production of new cementitious materials takes place. The cation exchange that causes the hydration and pozzolanic reaction that leads to the creation of aggregates and interparticle flocculation is responsible for their production. These findings suggest that cement may be utilized as a simple and effective method of loess stabilization, which will ultimately result in improved performance of the loess.

In contrast to the traditional fillers, clay, in particular, natural smectite clay represents an environmentally significant alternative to improve the properties of polymers. Compared to con-ventional nanofillers, smectite clay can effectively enhance the physical and mechanical properties of polymer nanocomposites with a relatively small amount of addition (< 5 wt%). The present study focuses on investigating the reinforcing efficiency of different amounts (up to 5 wt%) of a natural Brazilian smectite clay on the mechanical and thermal properties of poly(butylene terephthalate) (PBT) nanocomposites. Natural Brazilian clay modified by addition of quaternary salt and sodium carbonate (MBClay) was infused into the PBT polymer by melt extrusion, using a twin-screw extruder. It was found that the best properties for PBT were obtained at 3.7 wt% of modified BClay. Tensile strength at break exhibited an increase of about 60 %, flexural strength increased by 24 % and flexural modulus increased by 17 %. In addition, an increase in the crystallinity percentage of PBT/BClay nanocomposite was confirmed by DSC and XRD analysis, and a gain of about 45 % in HDT was successfully achieved due to incorporation of 3.7 wt% of MBClay.

Hippotherapy is a popular rehabilitation method for children with cerebral palsy (CP), which is done by riding an actual horse or a horse riding simulator (HRS) device. Riding a real horse is more expensive than using an HRS device due to its high maintenance cost. However, most HRS devices commonly sold in the market are designed as exercise devices, not rehabilitation devices. Most of them are designed to simulate a horse's walk, trot, canter, or gallop gait at various speeds. Hippotherapy aims to improve the walking ability of CP patients. Therefore, the device should aim to replicate the walking gait of a healthy human, the end goal of hippotherapy. This problem motivates us to design and build a specialized HRS device replicating the walking gait of a healthy human that is suitable for hippotherapy, which is achievable by simulating a horse walking gait with several adjustments. We first studied and observed the walking gait cycle of a horse, then analyzed and derived a formulation of it. We then continue by designing an HRS device using a single electrical rotational motor and mechanical means to replicate the walking gait of a horse, then tune it to an extent to replicate a human walking gait. To measure the performance of our design, we compare the gait of the user when riding our device versus walking.

Alternating TiB2-dcMS and Cr-HiPIMS layers are used to fabricate TiB2/Cr multilayer films. In-troducing a 5-nm-thick Cr interlayer deposited under a substrate bias of -60 V produces slight increases of both film hardness and elastic modulus. The TEM observation indicates that the Cr grains favor epitaxially growth on TiB2 interlayer, forming a coherent TiB2/Cr interface. This produces the hardness increasement. Mechanic measurement by using AFM illustrates that the coherent interface increases the elastic modulus of the Cr up to ~280 GPa, which is significantly higher than bulk material.

Although the dry ice method used to synthesize exfoliated graphite/graphene is little known and used, it has significant advantages over others: it is low cost, simple, and a large quantity of material can be obtained using some inorganic and highly available acids (which can be reused). Despite the above advantages, the main reason for its incipient development is the resulting presence of magnesium oxide in the final product. In the present work, three different treat-ments were tested to remove this remnant using some acid chemical leaching processes, making use of hydrochloric acid, aqua regia, and piranha solution. Based on the experimental evidence, it was found that using aqua regia and combining the leaching process with mechanical milling was the most efficient way of removing such a remnant, the residue being only 0.9 wt.%. This value is low when compared to that obtained with the other acid leaching solutions and purifi-cation process (2.8 - 29.6 wt.%). A mandatory high-energy mechanical milling stage was neces-sary during this treatment, in order to expose and dissolve the highly insoluble oxide without secondary chemical reactions on the graphenes. High-energy mechanical milling is an effective route to exfoliate graphite/graphene, which allows the magnesium oxide to be more susceptible to acid treatment. The obtained surface area was 504 m2g-1; this high value resulting from the in-tense exfoliation can potentiate the use of this material for a wide variety of applications.

With the increase in occupation-specific risks of lip cancer associated with solar radiation, there is a need for developing photoprotective lipsticks to protect skin against harmful effects of UV radiation. Considering the unique chemical and physical properties of low-molecular-weight organogelators (LMOGs), the present study intended to assess the UV protective properties of LMOGs-based lipstick formulations. In this study, dibenzylidene-D-sorbitol (DBS) and 12-hydroxystearic acid (12-HSA) were used to formulate lipsticks : L1 (1% DBS), L2 (10% 12-HSA), L3 (1.5% DBS) and L4 (control, no LMOGs). The lipstick formulations were tested for in vitro sun protection factors (SPF), UVA protection factor (UVA-PF), thermal, mechanical and texture analyses. Lipsticks with LMOGs exhibited higher UVA-PF and SPF, and more particularly 12-HSA-based lipstick. Results showed also the viscoelastic and heat-resistant properties of LMOGs and their effect of increasing pay-off values. In general, texture analysis indicating that 12-HSA-based lipstick was significantly harder to bend compared to control, while other formulations became softer and easier to bend throughout the stability study. Finally, sensorial and instrumental analyses permitted to classify lipsticks into two groups. This work suggests the potential use of LMOGs as a structuring agent for lipsticks paving the way towards more photoprotective and sustainable-derived alternatives.

The paper deals with the problems of direct kinematics related to a 2T6R robot, the direct kinematics of the plane mechanism of the robot. The direct kinematics of this proposed new robot help to study the movement, including the dynamic one, to determine the forces in the mechanism and to model the possible trajectories of the final effector point, thus determining the robot's working space and some of its multiple possible uses. Two totally different methods were used to verify the calculation relations, the results obtained by both methods being practically identical. The first method used is an original trigonometric method, and the second is an original geometrically analytical method.

The present study investigated the effects of alloying and nano-reinforcement on the mechanical properties (microhardness, tensile strength, and compressive strength) of Mg-based alloys and composites. Pure Mg, Mg-3Sn alloy, and Mg-3Sn+0.2GNP alloy-nanocomposite were synthesized by powder metallurgy followed by hot extrusion. The microstructural characteristics of the bulk extruded samples were explored using X-ray diffraction, field-emission scanning electron microscopy, and optical microscopy and their mechanical properties were compared. The microhardness, tensile strength, and compressive strength of the Mg-3Sn alloy improved when compared to those of monolithic Mg sample and further improvements were displayed by Mg-3Sn+0.2GNP alloy-nanocomposite. No significant change in the compressive strain to failure was observed in both the alloy and the alloy-nanocomposite with respect to that of the pure Mg sample. However, an enhanced tensile strain to failure was displayed by both the alloy and the alloy-nanocomposite.

The paper presents an analysis of the possibility of producing traction brushes from waste materials. Brushes are used to ensure good electrical contact between the rail and the pantograph. Slides are produced in the process of hot pressing, with parameters of heating up to max 175 ⁰C, at the minimal pressure value of 200 MPa. The developed brushes with a high (55-60%) content of recycled materials have comparable characteristics to commercial brushes, and some of the prototypes are even more durable and break-resistant.

The SARS-Cov-2 virus, which causes COVID 19, uses the cell surface protein ACE2 as receptor for entry into cells. Critically ill COVID-19 patients often require prolonged mechanical ventilation which can cause mechanical stress to lung tissue. In vitro studies have shown that expression of ACE2 in alveolar cells is increased following mechanical stretch and inflammation. Therefore, we analyzed transcriptome datasets of 480 (non-COVID-19) lung tissues in the GTex tissue gene expression database. We found that mechanical ventilation of the tissue donors increased the expression of ACE2 by more than two-fold (p<10^-6). Analyses of transcriptomes of mechanically ventilated mice in the GEO database indicate that this alveolar cell response to stretch and inflammation is mediated by the chemokine midkine. Using a novel big knowledge network approach (SPOKE) we also found in transcriptomes of pharmacological perturbations (LINCS) that corticosteroids down-regulate midkine in pulmonal cells, and confirmed this in GEO transcriptomes of animal studies. Thus, mechanical ventilation of patients with COVID-19 pneumonia may eo ipso facilitate viral propagation in the lung, further accelerating the pulmonal pathology that has necessitated mechanical ventilation in the first place. This vicious cycle presents a rationale for the temporary treatment with corticosteroids to modulate the midkine-ACE2 axis in ventilated COVID19 patients and for gentler ventilation protocols.

In this research, the feasibility of using bottom ashes generated by the combustion of biomass (olive pruning and pine pruning) as a source of aluminosilicates (OPBA) has been studied, replacing the metakaolin precursor (MK) in different proportions (0, 25, 50, 75 and 100 wt. % substitution) for the synthesis of geopolymers. As alkaline activator an 8 M NaOH solution and a Na2SiO3 have been used. The geopolymers were cured 24 hours in a climatic chamber at 60 ° C in a water-saturated atmosphere, subsequently demoulded and cured at room temperature for 28 days. The results indicated that the incorporation of OPBA waste, which have 19.7 wt. % of Ca, modifies the characteristics of the products formed after alkaline activation. In general terms, the incorporation of increasing amounts of calcium-rich ashes results in geopolymers with higher bulk density. The compressive strength increases with the addition of up to 50 wt. % of OPBA with respect to the control geopolymers, contributing the composition of the residue to the acquisition of a better behaviour mechanical. The results indicate the potential use of these OPBA waste as raw material to produce unconventional cements with 28-day curing strengths greater than 10 MPa, and thermal conductivities less than 0.35 W/mK.

The objective of this study is to conduct a mineralogical and chemical characterization of the mortars Roman archaeological site of Volubilis to rebuild spare mortars for restoration. We take samples of mortar, broken tile palate garden, and pavement mosaic Falavius Germanus houses. The analysis by X-ray diffraction reveals the coarse mortar Flavius Germanus is made of quartz and calcite with feldspar and probably, mica and dolomite in small amounts. The binder end is formed calcite and quartz. However, the broken tile mortar is formed by coarse particles, clay base mixed with a binder phase dominated by calcite. These results allowed us to reformulate spare mortars for the restoration of damaged Roman mosaics. The mortars are made up by 63.6% of lime and 36.4% of sand(with 4.19% of large grain, 71, 04% of coarse sand, 24.22%, of fine sand and 0.55% fines parts).The performance of these mortars was tested by mechanical testing.

In this work we produced biochar by coffee waste and use it as filler in epoxy resin composite with the aim to increase their electrical properties. The biochar and biochar based composite electrical conductivity were studied in function of applied pressure and compared with carbon black and carbon black composite. The applied pressure has the aim to investigate the behaviour of filler in powder or dispersed in composite in function of compression. Results showed that even if the coffee biochar has less conductivity if compared with carbon black in powder form, it has better conductivity in composite if compared with carbon black. Composite mechanical properties were tested and they are generally improved respect to neat epoxy resin.

Alumina dispersion-strengthened copper, Glidcop, is used widely in high-heat-load ultra-high-vacuum components for synchrotron light sources (absorbers), accelerator components (beam intercepting devices) and in nuclear power plants. Glidcop has similar thermal and electrical properties to OFE (oxygen free electrical) copper, but has superior mechanical properties, thus making it a feasible structural material; its yield and ultimate strength are equivalent to those of mild-carbon steel. The purpose of this work has been to develop a brazing technique to join Glidcop to Mo, using a commercial Cu-based alloy. The effects of the excessive diffusion of the braze along the grain boundaries on the interfacial chemistry and joint microstructure, as well as on the mechanical performance of the brazed joints, has been investigated. In order to prevent the diffusion of the braze into the Glidcop alloy, a copper barrier layer has been deposited on Glidcop by means of RF-sputtering.

In this study, a 5vol. % (TiBw+TiCp)/Ti composite pancake with a diameter of 260mm was prepared by casting followed by open die forging in (α+β) phase region. The microstructures of the composite pancake are inhomogeneous, in terms of both matrix microstructure and distribution of reinforcements. The matrix microstructures were gradually refined from the periphery to centre of the pancake. The TiBw and TiCp reinforcements tend to be uniformly distributed in the centre region and. It is suggested that the microstructure difference can be mainly ascribed to the temperature variation from the periphery to the centre. Additionally, tensile testing results showed that the centre region of the composite pancake exhibits higher strength than the peripheral region. The strengthening mechanism and the softening behavior of the composite pancake with temperature is discussed.

In this short communication, we conducted first-principles calculations to explore the stability of boron monochalcogenides (BX, X=S, Se or Te), as a new class of two-dimensional (2D) materials. We predicted BX monolayers with two different atomic stacking sequences of ABBA and ABBC, referred in this work to 2H and 1T, respectively. Analysis of phonon dispersions confirm the dynamical stability of BX nanosheets with the both 2H and 1T atomic lattices. Ab-initio molecular dynamics simulations reveal the outstanding thermal stability of all predicted monolayers at high temperatures over 1500 K. BX structures were found to exhibit high elastic modulus and tensile strengths. It was found that BS and BTe nanosheets can show high stretchability, comparable to that of the graphene. It was found that all predicted monolayers exhibit semiconducting electronic character, in which 2H structures present lower band-gaps as compared with 1T lattices. The band-gap values were found to decrease from BS to BTe. According to the HSE06 results, 1T-BS and 2H-BTe show respectively, the maximum (4.0 eV) and minimum (2.06 eV) electronic band-gaps. This investigation introduces boron monochalcogenides as a novel class of 2D semiconductors with remarkable thermal, dynamical and mechanical stability.

The management of existing water distribution system (WDS) is challenged by ageing of infrastructure, population growth, increasing of urbanization, climate change impacts and environmental pollution. Therefore, there is a need for integrated solutions that support decision makers to plan today, while taking into account the effect of these factors in the mid and long term. The paper is part of a more comprehensive project, where advanced hydraulic analysis for WDS is coupled with a dynamic resources input-output analysis model. The proposed modeling solution can be used to optimize the performance of a water supply system while considering also the energy consumption and consequently the environmental impacts. Therefore, as a support tool in the management of a water supply system also in the intervention planning. Here a possible application is presented for rehabilitation/replacement planning while maximizing the network mechanical reliability and minimizing risk of unsupplied demand and pressure deficit, under given economic constraints.

High level of noise is a disturbance to the human environment. Noise in industries is also an occupational hazard because of its attendant effects on workers’ health. Noise presents health and social problems in industrial operations, and the source is related to the machineries used in the industries. One of the unique features of the noise associated with wood machinery is the level of exposure and duration. Equipment used in a factory can be extremely loud. They can produce noise at decibels high enough to cause environmental health and safety concerns. The mechanically driven transport and handling equipment, cutting, milling, shaping and dust extractor installations in the wood industry generate noise. The sources of noise pollution have increased due to non-compliance with basic safety practices. The increased use of locally fabricated machine in the industry has increased the level of noise and vibration. The effects of industrial noise pollution as discussed include: increase in blood pressure; increased stress; fatigue; vertigo; headaches; sleep disturbance; annoyance; speech problems; dysgraphia, which means reading/learning impairment; aggression; anxiety and withdrawal. As presented in this paper, noise control techniques include; sound insulation, sound absorption, vibration damping and Vibration isolation.

The contribution aims to bring forth a novel synthesis route in developing transparent UV-LED curable coatings accounting various exposure options. A selection of perfluoropolyether (PFPE)-urethane methacrylate and acrylate resins, free-radical photo-initiator Omnirad 2100, and two distinct silane based crosslinking agents were blended under a weight ratio of 75:20:5 (without crosslinker) and 70:15:5:10, respectively. The coatings were cured under a UV-LED 4 x 3 matrix light emitting source, in a chamber under controlled atmosphere, by means of an in-house developed conveyor belt type platform, at different conveyor belt speed (5, 50, 150, 250, and 500 mm/s). The morphologies of fabricated coatings were characterized by FTIR revealing high conversion rates (e.g., from 98 to 100%) for increased exposure time as resulted from the 5 or 50 mm/s values, on all combinations. Dynamic-mechanical and optical properties of UV-LED cured transparent coatings were also investigated. A negative shift of a glass transition temperature values with a decrease in exposure time, in all combinations, from about 60 °C to 30 °C, along with storage moduli lowering in the glassy plateau further favor on higher exposure times for curing. The refractive indices of polymers were from 1.38 to 1.40, whereas the thermo-optic coefficients are showing minor changes around value of 2.55∙10-4 K-1.

TiNbZrTa alloys are promising for multidisciplinary applications, such as refractory and biomedical purposes due to their high thermal stability and non-toxicity. Hardness and elastic modulus are among the key features for their adequate industrial applications. The influence of porosity and Ti/Ta ratio were investigated on TiNbZrTa alloys produced by three different processing routes, i.e., (i) blend element and posterior press and sintering (BE + P&amp;S), (ii) mechanical alloying with press and sintering (MA + P&amp;S), and (iii) arc melting and casting. Atomic diffusion was improved during processing, resulting in lower porosity in the following order: casting &lt; MA + P&amp;S &lt; BE + P&amp;S. Ta offered limited atomic diffusion due to its high melting point compared to other constituent elements. Thus, the total porosity of alloys increased with increasing the Ta contents, i.e., by lowering the Ti/Ta ratio. However, the Ti/Ta ratio did not considerably affect the bonding energy or the elastic modulus. Hardness was increased significantly in dense alloys compared to the porous ones. However, porosity and Ti/Ta ratio did not show a clear trend in hardness among the porous alloys.

Background/Objectives: The purpose of this study was to evaluate the relationship between 1-year mortality and health insurance benefit extension policy items in severe pneumonia pa-tients requiring mechanical ventilation using a South Korean nationwide cohort. Methods: A nationwide population-based retrospective study was conducted using the Korean National Health Insurance database. A total of 1,099 patients (542 patients in the health insurance benefit item group and 557 patients in the control group) were included. The primary outcome was 1-year mortality. Results: Among patients with health insurance benefit extension policy items, 203 patients (37.5%) were diagnosed with hemato-oncological disease, who were categorized as group A, and 339 patients (62.5%) were diagnosed with cerebrovascular, cardiovascular, or rare diseases, who were categorized as group B. Group B had lower 1-year mortality (50.7% vs. 62.5%, P

The development of offshore wind farms requires robust bonding solutions that can withstand harsh marine conditions for the easy integration of secondary structures. This paper investigates the durability performance of two adhesives: Sikadur 30 adhesive and Loctite UK 1351 B25 for use in offshore wind environments. Tensile tests on adhesive samples and accelerated aging tests were carried out under a variety of temperature and environmental conditions, including both dry and wet conditions. The long-term effects of aging on adhesive integrity are investigated by simulating the operational life of offshore installations. The evolution of mechanical properties, studied under accelerated aging conditions, provides an important indication of the longevity of structures under normal conditions. The results show significant differences in performance be-tween the two adhesives, highlighting their suitability for specific operating parameters. It should also be noted that for both adhesives, their exposure to different environments (seawater, distilled water, humid climate) over a prolonged period has shown that i) Loctite adhesive has a slightly faster initial uptake than Sikadur adhesive, but the later reaches an asymptotic plateau with a lower maximum absorption rate than Loctite adhesive; and ii) a progressive deterioration in the tensile properties following an exponential function. Therefore, aging behavior results showed a clear correlation with Arrhenius' law, providing a predictive tool for the aging process. Thus, the aging process of the two adhesives follows Arrhenius kinetics.

Conductive hydrogels combine the properties of both hydrogels and electrical conductivity, making them soft, flexible, and biocompatible. These properties enable them to conform to irregular surfaces, stretch and bend without losing their electrical conductivity, and interface with biological systems. Conductive hydrogels can be utilized as conductive traces, electrodes, or as a matrix for flexible electronics. Exciting applications in sensors, tissue engineering and human-machine interaction have been demonstrated worldwide. This review comprehensively covers the progress in this field, focusing on several main aspects: functional materials, performance improvement strategies, and wearable applications in human-related areas. Furthermore, the major approaches and challenges for improving their mechanical properties, conductivity, and long-term stability are systematically summarized.

The nickel-chromium-molybdenum alloy 625 exhibits an excellent combination of mechanical properties and corrosion resistance. However, the high temperature plastic deformation process and the heat treatment represent critical aspects and the adoption of non-optimal parameters can result in excessive grain coarsening and loss in mechanical strength. This detrimental behavior is worsened by the presence of a narrow region of temperatures and strain rates for complete recrystallization and the absence of phase transformation temperatures. In this alloy, the presence of sufficient amounts of niobium, titanium and aluminum permits slow age-hardening response upon single-aging treatments. Therefore, when the soft- or solution-annealed condition is associated with insufficient mechanical properties, this potentiality can be exploited to improve the mechanical strength and prevent waste of material and resources. Since the precipitation kinetic of the hardening γ^'' phase can be accelerated by prior nucleation treatment, different time-temperature combinations of double aging at 732 °C and 621 °C are investigated to reduce the overall heat treatment time. However, the simultaneous formation of Cr-rich carbides can dramatically affect the intergranular corrosion resistance. For this reason, a performance map is developed to compare all the tested conditions and identify the best compromise in terms of mechanical strength and corrosion rate.

Industry 4.0 is an industrial paradigm that is causing changes in form and substance in factories, companies and businesses around the world, and is impacting work and education in general. In fact, the disruptive technologies that frame the fourth industrial revolution have the potential to improve and optimize manufacturing processes and the entire value chain, which can lead to an exponential evolution in the production and distribution of goods and services. All these changes imply that the fields of engineering knowledge must be oriented towards the concept of Industry 4.0, for example Mechanical Engineering. The development of various physical assets that are used by cyber-physical systems and digital twins is based on Mechanics. However, the specialized literature on Industry 4.0 says little about the importance of Mechanics in the new industrial era and more importance is given to the evolution of Information and Communication Technologies and Artificial Intelligence. This article presents a frame of reference about the importance of Mechanical Engineering in Industry 4.0 and proposes an extension to the concept of Mechanics 4.0, recently defined as the relationship between Mechanics and Artificial Intelligence. For the analysis of Mechanical Engineering in Industry 4.0, the criteria of the four driving forces that defined Mechanics in the third industrial revolution was used. An analysis of Mechanical Engineering Education in Industry 4.0 is presented, and the concept of Mechanical Engineering 4.0 Education is improved. Finally, the importance of making changes in the educational models of engineering education is described.

Composites, and especially carbon fiber reinforced plastics (CFRPs), are increasingly used in the automotive, aerospace, and aviation industries, and as a result, CFRP production has increased dramatically, leading to a corresponding increase of waste. Landfill and incineration of waste are likely to be restricted as a result of the legislation, thus highlighting the need for efficient recycling methods for CFRPs. However, the recycling of CFRP is very challenging, mainly due to the difficulty of removing the thermosetting matrix. This study reports a pre-screening of the solvolysis recycling process for CFRPs based on the mechanical properties of the recovered fibers. To this end, solvolysis tests were conducted on unidirectional CFRP samples under supercritical and subcritical conditions using acetone and water. The solvolysis tests were conducted for various conditions of temperature, pressure, and reaction time. The efficiency of the recycling processes has been evaluated through a morphological and a mechanical characterization of the recovered fibers. In most cases, the decomposition efficiency of the epoxy resin, measured in terms of mass, ranged between 90 and 100%. Moreover, the scanning electron microscopy images of the recovered fibers showed negligible traces of resin residues and no detectable signs of physical damage or any changes in morphology with regard to diameter. Finally, the single-fiber tension tests revealed that that the recovered fibers retained more than 61% of their initial Young's modulus and 70% of their tensile strength.

With the advancement of Additive Manufacturing and its applications in various industrial segments, it becomes increasingly important to investigate the processability parameters associated with nano-reinforcement. This study examines the influence of infill parameters, such as patterns (hexagonal, triangular and concentric), shape (solid and honeycomb) and concentrations by mass of Carbon Nanotubes (CNTs) at 1.0 wt% and 2.0 wt% on the mechanical compression properties of the 3D printed material. In this sense, nanocomposites based on Polylactic Acid (PLA) matrix nano-reinforced by CNTs were characterized using the Scanning Electron Microscopy -SEM, X-ray Diffraction, Raman Spectroscopy techniques and mechanical analysis. The mechanical properties of both the matrix and the nanocomposites were determined through mechanical compression tests, in accordance with [1]. SEM revealed compacted regions, voids, and detachment in the structures. XRD characterization indicated PLA predominantly amorphous nature, while CNTs exhibited characteristic diffractions of carbon nanotubes. Raman characterization showcased bands and characteristic vibrations of CNTs and PLA, nanocomposites' vibrational modes combine those of CNTs and PLA. Mechanical compression analysis indicates a direct influence of infill pattern, shape, and nano-reinforcement. The triangle pattern outperformed other patterns, exhibiting a 15.03% increase compared to concentric and 8.8% compared to hexagon infill. In nanocomposites, all showed higher compressive strength than the matrix. For PLA/1.0%CNTs, strength was 16.8%, and for PLA/2.0%CNTs, it reached 39.2%. In honeycomb shapes with infill variations, the triangular pattern excelled with a 0.97% increase over concentric and 6.12% over hexagon patterns. Honeycomb results indicate a 59.6% increase for (PLA/1.0%CNTs) and a 0.48% increase for (PLA/2.0%CNTs) compared to the matrix. This study highlights 3D printing parameters, emphasizing the effectiveness of the triangular pattern and the enhanced strength with the addition of CNTs, providing insights to enhance products manufactured through Additive Manufacturing.

Excessive activation of frog eggs, so called overactivation, can be initiated by strong oxidative stress, leading to expedited calcium-dependent non-apoptotic cell death. Overactivation also occurs spontaneously, albeit with a low frequency, in natural populations of spawned frog eggs. Currently, cytological and biochemical events of the spontaneous process are not characterized. In the present study, we demonstrate that spontaneous overactivation of Xenopus frog eggs, similarly to oxidative stress- and mechanical stress-induced overactivation, is characterized by the fast and irreversible contraction of the egg’s cortical layer, increase in the egg size, depletion of intracellular ATP, drastic increase in the intracellular ADP/ATP ratio, and degradation of M phase-specific cyclin B2. These events manifest in eggs in the absence of caspase activation within just one hour of triggering overactivation. Importantly, large amounts of ATP and ADP leak from the overactivated eggs, indicating that plasma membrane integrity is compromised in these cells. The rapture of the plasma membrane and acute depletion of intracellular ATP define explicitly necrotic cell death. Finally, we report that egg overactivation can occur in the frog’s genital tract. Our data argue that mechanical stress may be a key factor promoting egg overactivation during natural spawning in frogs.

Steel slag and GBFS are wastes generated during the steel and iron smelting process, characterized by their considerable production rates and extensive storage capacities. After grinding, they are often used as supplementary cementitious materials. However, the intrinsic slow hydration kinetics of steel slag-GBFS cementitious material (SGM) when exposed to a pure water environment result in prolonged setting times and diminished early-age strength development. The incorporation of modifiers such as gypsum, clinker, or alkaline activators can effectively improve the various properties of SGM. This comprehensive review delves into existing research on the utilization of SGM, examining their hydration mechanisms, workability, setting time, mechanical strengths, durability, and shrinkage. Critical parameters including the performance of base materials (water-to-cement ratio, fineness, and composition) and modifiers (type, alkali content, and dosage) are scrutinized to understand their influence on the final properties of the cementitious materials. The improvement mechanisms of various modifiers on properties are discussed. This the promotes resource utilization of industrial solid wastes and provides theoretical and technical support for the application of SGM.

The construction industry generates significant CO2 emissions, and rebar is a major contributor to this environmental impact. Extensive research has been conducted to address this issue. Recent advancements have introduced algorithms to reduce rebar waste and consumption, demonstrating the feasibility of achieving near-zero rebar cutting waste (N0RCW) by considering special-length rebars. However, conventional lap splices, the most common rebar joint method, consistently consume excessive rebar quantities despite extending beyond their mandated zones. Conversely, couplers eliminate rebar lengths required for lapping splices, reducing the usage of rebar. Applying special lengths and couplers in heavily loaded structures like diaphragm walls can significantly reduce rebar usage and cutting waste, consequently reducing CO2 emissions and associated costs. This study aims to optimize rebar consumption and sustainability in diaphragm wall structures by integrating mechanical couplers with a special-length rebar approach. A case study confirmed a substantial reduction in purchased rebar usage (17.95% and 5.38%) and carbon emissions (15.24% and 2.25%) compared to the original design and previous study, respectively. Broadly implementing the proposed method across various buildings and infrastructure projects could further multiply these benefits, fostering the achievement of SDGs adopted by the United Nations for sustainable construction.

PURPOSE: The aim of this study was to identify the incidence of early mechanical failure in the first post-surgical year in patients who had undergone spinal surgery, and to assess the related risk factors. METHODS: Retrospective observational study of a prognostic cohort was conducted at an orthopaedic hospital, examining all patients with spine degenerative disease who consecutively underwent arthrodesis surgery between March 2018 and March 2019. The incidence of postoperative mechanical failure during the first year was calculated as primary outcome; the time between the date of the implant surgery and diagnosis of the mechanical failure was calculated as secondary outcome. RESULTS: A total of 237 patients were identified for statistical analysis. The median age of the group of patients was 47 years (IQR of 44), and 66.6% were female. The incidence of mechanical failure in the first postoperative year was 5.1% overall with 12 events and the median time between surgery and the need for revision surgery was 5 months (IQR=7.75). ASA score (OR= 2,39; p=0.134), duration of the surgical procedure (OR=1,27; p=0,006) and inability to walk at discharge (OR=7,86; p=0,072) were independent risk of factor associated with the mechanical failure. CONCLUSION: Higher ASA score and longer duration of surgery are risk factors for mechanical failure in the first year in patients who had undergone spinal surgery and must be carefully considered when planning spinal surgery. During hospitalization, recovery of ambulation must be encouraged to prevent mechanical failure. All these factors are useful in identifying patients with a closer follow-up is needed.

Considering nutritional qualities of gofio (Gf) and aloe vera juice (AVJ), their combination is indicated as an easy and fast source of ingest of basic bio elements. As the texture of the final product must be accepted by customers, the influence of Gf concentration on the rheological behavior of Gf/AVJ suspensions was determined. Shear thinning index of AVJ maintains unaltered despite the presence of Gf particles, although the viscosity value increases as expected. Linear viscoelastic studies on Gf/AVJ confirmed this is a viscoelastic liquid that changes from chewy to creamy texture with Gf concentration increase.

In the last two decades, gelatin-based hydrogels have been widely used as tissue engineering scaffolds due to their excellent biocompatibility, biodegradability, easy processability, transparency, non-toxicity, and reasonable structural similarity to the natural extracellular matrix (ECM). However, intrinsic low mechanical properties of gelatin are not structurally and mechanically suitable to support cell growth and proliferation. That’s why various crosslinking strategies including physical, chemical, enzymatic and combination of them as well as networking patterns including double network, interpenetrating network and nano reinforcing mechanism have been utilized to enhance the structural stability and mechanical integrity of gelatin. In this review, the advances in modulating the mechanical properties of gelatin-based hydrogels for the design and development of structurally stable scaffolds for tissue engineering are discussed. The optimized crosslinking parameters with the adequate mechanical properties of gelatin-based hydrogels are reviewed. Gelatin-based scaffolds for a wide range of tissue engineering applications, such as bone, cartilage, cardiac, skin, and nerve tissue engineering are also outlined. Lastly, current challenges and future perspectives in this research field are presented.

The topic of modification of magnesium oxychloride cement (MOC) via specific functional additives is very much pronounced in the research of alternative building materials. This study deals with the co-doping of MOC by 1D and 2D carbon nanomaterials in order to improve its mechanical properties while using tannic acid (TA) as a surfactant. Furthermore, the effect of TA on MOC also covers the improvement of water resistance. As a filler, three size fractions of standard quartz sand are used. The proposed types of MOC-based composites show promising results considering their mechanical, macro- and microstructural, chemical, and hygric properties. The use of 1D and 2D nanoadditives and their mixture enables the improvement of the flexural strength and most of all softening coefficient, the durability parameter characterizing the resistance of the prepared materials to water. For samples immersed in water for 24 h, the compressive strength of all modified composites tested was higher than that of the reference composite. Quantitatively, the developed co-doped composite shows mechanical parameters comparable to or even better than those of commonly used Portland cement-based materials, while maintaining high environmental efficiency. This indicates its potential use as an environmentally friendly alternative to Portland cement-based products.

In order to further reduce the emissivity of the hydrophobic low infrared emissivity composite coating and improve the mechanical properties of the coating, the dispersant, adhesion enhancer, and defoamer were used to improve the dispersion state of the fillers, the interface structure, and the surface state of the hydrogen silicone oil modified polyurethane/Al composite coating. The effects of dispersant, adhesion enhancer, and defoamer on the micro-structure, emissivity, glossiness, hydrophobic property, and mechanical properties of the coating were systematically studied. The results show that the polycarboxylate anionic dispersant can obviously improve the dispersion state of flake Al powder and nano-SiO2 in the coating, so that the infrared emissivity of the coating can be reduced, and the coating can have higher hydrophobic and mechanical properties. The bonding strength between the resin matrix and the metal substrate of the coating can be significantly improved by the adhesion enhancer through the bridging action, so that the adhesion strength and impact strength of the coating can be significantly improved. The defoamer can significantly reduce the pores in the coating, so that the surface state of the coating can be significantly improved, and the mechanical properties of the coating can be significantly improved. The coating has the best emissivity (0.527), glossiness (4.3), adhesion strength (grade 1), impact strength (40 kg.cm), and hydrophobic property (water contact angle (WCA) is 140o) when the amount of dispersant, adhesion enhancer, and defoamer is 5 wt%, 4 wt%, and 1 wt%, respectively.

The hot rolling in the process chain of the aluminium rolled products present the critical element of material quality and influence on productivity. The desire to increase the letter demand modifications of hot rolling, consequential changes of microstructure, crystallographic texture, mechanical and formability properties must be knowledge and consistently considered in planning the rolling process and rolled product. Achieving lower thicknesses of the hot-rolled band would enable fewer passes with cold rolling; consequently, hot rolling with the same number of passes will complete with lower temperatures. Microstructural and texture characterization with the optical microscope and scanning electron microscope for the hot-rolled band 3.25 mm the smaller grains appeared in the center of the cross-section, unlike for the hot-rolled band 6 mm, the smaller grains were detected on the upper and bottom position of the cross-section. Furthermore, the comparison shows also that the hot-rolled band 6 mm has 64 % of random texture components and 83 % of recrystallized grains, and the proportional adjustment for the hot-rolled band 3.25 mm has the 42 % of random texture components and 55 % of recrystallized grains. For the mechanical testing results, the elongation values in rolling and transverse directions significantly differ just in the case of a hot rolled band of 3.25 mm. Consequently, the earing results are more than 1.5 % higher for the hot-rolled band, 3.25 mm, than the hot-rolled band, 6 mm.

The evolution of transportation has been inextricably tied to the progress of civilization. Through innovation, the automobile business has been working to improve safety, quality, and compliance with environmental regulations. Electric vehicles have made significant strides in this area, but optimizing their efficiency requires a special focus because they expend energy that can be recovered in a variety of ways. Energy harvesting, a cutting-edge technology that captures wasted energy from vehicles, has recently received a lot of attention as it constitutes a means to improve the efficiency of electric vehicles. Dissipated energy can be converted into electricity using regenerative energy recovery systems and put to various uses. This study tenders a thorough examination into energy recovery technologies which could be applied to the various types of energy dissipated in electric vehicles. Firstly, the paper investigates the possible sources of energy recoverable from an electric vehicle, as well as the various types of energy dissipated. Secondly, the article examines the energy recovery technologies most frequently used in vehicles, categorizing them according to the type of energy and application. Finally, it determines that with further research and development, energy harvesting holds considerable potential for improving the energy efficiency of electric vehicles. New and innovative methods for capturing and utilizing wasted energy in electric vehicles can be established. The potential benefits of applying energy recovery systems in electric vehicles is a vital issue for the automobile industry to focus on due to the potential benefits involved. The ongoing progress currently being made in this field is expected to play a significant role in shaping the future of transportation.

Bobbin Tool Friction Stir Welding (BTFSW) is a variant of FSW process using the special two shoulder tool that forms the top and bottom weld surface. As such, a significant simplification of welding setup is achieved. One of the dominant parameters of BTFSW process is the interference between tool shoulder pinch gap and weld metal thickness. In this research, the influence of interference of the square pin tool with convex shoulders on process temperature, microstructure, tensile, impact and bend performance were studied, and appropriate correlations were devised. The base metal was aluminum-magnesium alloy, with the interference varied in the range of 0.1 to 0.5 mm. The worm defects and irregularities were found in all specimens except in specimen welded with 0.4 mm interference. Optimal interference of 0.4 mm resulted in the highest mechanical properties, which, in terms of tensile strength and reduction of area were similar to the base metal. Furthermore, impact strength was significantly higher, which was attributed to grain refinement effect in the nugget zone.

Fe rich soft magnetic alloys are candidates for applications as magnetic sensors and actuators. These alloys can also be added to hard magnetic compounds to obtain spring magnets. In this work we produce two nanocrystalline Fe-Zr-B-Cu alloys by the powder metallurgy powder technology of mechanical alloying. The increase of the boron content favors the reduction of the crystalline size. Thermal analysis (by differential scanning calorimetry) shows at temperatures between 450 and 650 K wide exothermic processes, associated with the relaxation of tensions of the alloys produced by milling. At high temperatures, a main crystallization peak is found. The apparent activation of this process was determined by Kissinger and isoconversional methods. The values are compared with those found in the scientific literature. Likewise, adapted thermogravimetry permits to determine the Curie temperature. The functional response has been analyzed by hysteresis loop cycles. According to the composition, the decrease of the Fe/B ratio diminishes the magnetic soft behavior.

The purpose of this study was to determine changes in the mechanical properties of the thigh and lower leg musculature during the early follicular and ovulatory phases. Subjects were 15 female university students with normal menstrual cycles. The early follicular and ovulatory phases were estimated by the basal body temperature method, ovulation kits, and salivary estradiol concentration measurement. The MyotonPRO digital palpation device (Myoton AS, Tallinn, Estonia) was used to measure muscle and tendon stiffness in the early follicular and ovulatory phases. Measurement sites were the rectus femoris (RF), vastus medialis (VM), patellar tendon (PT), medial head of gastrocnemius, soleus, and Achilles tendon. No significant differences in stiffness of all muscle tendons were identified between the early follicular and ovulatory phases. In the ovulatory phase, a significant positive correlation was seen between stiffness of RF and PT, and between stiffness of VM and PT. These results suggest that the stiffness of muscles and tendons of anterior sites of the thigh and posterior sites of the lower leg may not change between the early follicular and ovulatory phases. During the ovulatory phase, tendons may also be stiffer in individuals with stiffer anterior thigh muscles.

The preparation of new materials based on starch for the development of biodegradable packaging is increasing, however, the poor properties of this biopolymer for this application causes an area of opportunities for the improvement of water vapour permeability (WVP), mechanical properties, thermal properties, hydrophilicity, water absorption, among others. Hence, starch has been combined with other polymers such as polyvinyl alcohol, which has shown an improvement in the mechanical properties of starch, also, the use of clays suggests that the properties of response to water can be improved. Therefore, in this work, the preparation and characterization of starch-PVA-nanoclay films prepared by solvent casting is reported. The results obtained suggest that the sonication of nanoclay is necessary to reach a good dispersion, which promotes a strong interaction among starch-PVA-nanoclay. In addition, the properties of WVP and mechanical properties of films improved with incorporation of nanoclay, the concentration of 0.5% w/v of nanoclay showed to be the best concentration due to concentrations of 1.0 and 1.5% w/v were poorer than 0.5% w/v. Accordingly, the successful incorporation of nanoclays into the matrix starch-PVA suggests that this material is a good candidate for use as packaging.

Objective: This study aims to identify the impact of nutritional factors on mechanical ventilation duration for critical patients. Patients and Methods: The current study was a single-center, prospective observational design which enrolled one-hundred critically ill patients who were admitted to an intensive care unit (ICU). It demonstrates purposive sampling and also performs the descriptive nutritional factors influencing the mechanical ventilation duration. Daily calories target requirement scale (DCRS), subjective global assessment form (SGA), dyspnea assessment form, and APACHE II have been used as methods in the study along with time to initial enteral nutrition (EN) after 24-hour admission and daily calories target requirement over 7 days to assess patients. Data is analyzed using the multiple regressions. Results: As a result, nutritional status monitoring, time to initial EN, calories and target requirements are statistically positive significance associated with the mechanical ventilation duration respectively (R = 0.54, R = 0.30, R= 0.40, p < 0.05). However, age, illness severity, and dyspnea scales are not associated with the mechanical ventilation duration (p> 0.05). Therefore, the nutritional status, malnutrition scores and calorie target requirements can be used to significantly predict the mechanical ventilation duration. The predictive power is 58 and 28.0% of variance. The most proper influencer to predict the mechanical ventilation duration is nutritional status or malnutrition scores. Conclusion: The research findings show that the nutritional status, time to initial EN, and calorie target requirement within 7 days of admission are associated with the mechanical ventilation duration in the critical patients. Therefore, it can be used to develop guidelines reducing the mechanical ventilation duration and to promote the ventilator halting for critical patients.

The distributed long-range sensing system using the standard telecommunication single-mode optical fiber in a function of a distributed sensor for sensing of mechanical vibrations is described. Various events generating vibrations such as walking or running person, moving cars, trains and others can be detected, localized and classified. The sensor and related sensing system components were designed and constructed and the system was tested both in the laboratory and in the real situation with 88 km telecom optical link, and the results are presented.

Polymethyl methacrylate (PMMA) is a transparent thermoplastic with excellent optical properties, transparent surface, low moisture absorption, tensile and electrical resistance. In this study, the alloy was prepared through PMMA and cycloolefin copolymer (COC) due to some similar properties. The mechanical test showed that properties such as impact resistance, elongation, tensile, and flexural strength decreased by adding COC by up to 20% due to less incompatibility and miscibility, but mentioned properties improved by adding COC 40% due to sub-phase generation. The DSC and DMTA tests showed improvement in the thermal properties of alloys by adding 40% COC. SEM micrographs exhibited a softer surface and more phase elongation of the alloy. Finally, the sample was selected as the optimal sample in terms of mechanical properties irradiated by electron beam, and amplification results showed that a dose of 50 KGY increased the mechanical and thermal properties relatively.

Metal 3D printing technology is a promising manufacturing method, especially in the case of complex shapes. The quality of the printed product is still a challenging issue for mechanical applications. The anisotropy of the microstructure, imperfections, and residual stress are some of the issues that diminish the mechanical properties of the printed sample. The simulation could be used to investigate some technical details, and this research has tried to computationally study the metal 3D printing of austenitic stainless steel to address austenite microstructure and local yield strength. Two computational codes were developed in Visual basics 2015 to simulate the local heating/cooling curve and subsequent austenite microstructure. A stochastic computational code was developed to simulate austenite grain morphology based on calculated thermal history. Then Hall-Pitch equation was used to estimate the yield strength of the printed sample. These codes were used to simulate the effect of temperature of the printer’s chamber on microstructure and subsequent yield strength. The austenite grain topology is more columnar at a lower temperature. The percentage of the equiaxed zone will be increased at a higher chamber’s temperature. Almost a fully equiaxed austenite microstructure will be achieved at 800 C chamber’s temperature, but the last printed layer, which is columnar and can be removed by cutting then. The estimated local austenite grain size and the local yield strength in the equiaxed regions are in the range of 15 to 30 μm and 270 to 330 MPa at 800 C temperature of printer’s chamber, respectively.

With the emergence of COVID-19 we are confronted with a new clinical picture of acute respiratory distress syndrome in the intensive care unit. In the majority of patients, the respiratory mechanics are very different from the “normal” ARDS patient. We measured transpulmonary pressure and dead space ventilation to assess the effects of high and low PEEP levels on lung compliance and ventilation-perfusion mismatching. Advanced respiratory mechanics were assessed in 14 patients. Compared to ARDS patients, lung compliance was relatively high (61 ± 5 mL/cmH₂O). COVID-19 patients had high dead space ventilation and gas exchange impairment (Bohr 52 ± 3%; Enghoff modification 67 ± 2%; ventilatory ratio 2.24 ± 0.23). we show that higher PEEP levels decrease lung compliance and in most cases increase dead space ventilation, indicating that high PEEP levels probably cause hyperinflation in patients with COVID-19. We suggest using prone position for an extended period of time, and apply lower PEEP levels as much as possible.

The Wolfram (W), Silicium (Si) and Molybdenum (Mo) doped Co-Cr biomedical alloy were fabricated by additive manufacturing method, which is part of powder metadology. The mixture of Wolfram (W), Silicium (Si), Chrome (Cr) and Cobalt (Co) alloy is known good wear and corrosion resistance among of biomedical applications. By addition of Molybdenum (Mo) into the structure of alloy, the structure become more stbale also increase the corrosion and wear resistance. In addition, the effects of secondary annealing process on the alloy were investigated. The microstructure of the produced alloy was analyzed by X-ray diffraction method XRD, Energy Dispersive X-Ray Analysis EDX and scanning electron microscope SEM. Moreover, Electrochemical corrosion test, micro hardness and density measurements were performed to investigate the mechanical properties of the alloy. As a result of the analyzes, the effects of Molydenum (Mo) doped and secondary annealing on the microstructure and mechanical properties of bioalloying were determined.

The aim of this work was to prepare bioplastics from renewable and biodegradable molecules. In particular, the bioplastics were produced by using as biopolymer source the grass pea (Lathyrus sativus L.) flour, the proteins of which were structurally modified by means of microbial transglutaminase, an enzyme able to catalyze isopeptide bonds between glutamines and lysines. We analyzed, by means of Zeta-potential, the flour suspension with the aim to choose which pH is more stable for the production of film-forming solutions. The bioplastics were produced by casting and they were characterized according to several technological properties. Optical analysis demonstrated that films cast in the presence of the microbial enzyme are more transparent compared to the untreated ones. Moreover, the visualization by Scanning Electron Microscopy demonstrated that the enzyme-modified films possessed a more compact and homogeneous structure. Furthermore, the presence of microbial transglutaminase allowed to obtain film more mechanically resistant. Finally, digestion experiments under physiological conditions performed in order to obtain information useful for applying these novel biomaterials as carriers in the industrial field, indicated that the enzyme-treated coatings might allow the delivery of bioactive molecules in the gastro-intestinal tract.

For development and successful application of any material, a clear understanding of their mechanical behavior is one of the most important things, but when it comes to nanofibers networks it become a challenge due to, their high porosity, many scales in their structure, and characteristics non-linear. Therefore, an experimental methodology in conjunction with a theoretical model that can fully consider their characteristics is still needed. In this work we proposed a model that incorporates the propagation of the elastic waves in two-phase media to determine the effective elastic modulus of electrospun membranes of PLA/gelatin given the mechanical properties of nanofibers, shape, distribution and concentration. The model was verified via laser ultrasonic testing. It was found that the values predicted for the effective modulus by the model were higher than the values obtained from experimental results. One explanation is due to the experimental density. As a result, the P-Wave velocity from the model best fit to experimental results and it has the same behavior, decrees as the concentration of gelatin in the solution. These results indicate the model and experimental methodology can assist in the dressing of nanofibers networks and electrospun materials.

The developed microstructure features a long with mechanical properties in vacuum brazing of commercially pure Ti-alloy using Ti₂₀Zr₂₀Cu_60-x-Ni_x (x=10, 20, 30, 40 and 50) metallic filler. Brazing temperatures and holding times employed in this study were 1240-1279 K (967-1006^oC) for a period of 10 min, respectively. The mechanical properties of brazed joints were evaluated by nanoindention at a constant peak load of 5000 μN and tensile tests. The number of intermetallic phase, such as NiTi₂, Ti₂Cu, (Ti, Zr)₂Cu, (Ti, Zr)₂Ni, β(Ti, Zr), α-Ti and NiTi. The solid solution matrix have been identified at 1279 K out of these different regions the NiTi₂ rich region had the highest nanohardness of 17 GPa, It is interesting to note that among five different glasses, the Ti₂₀Zr₂₀Cu₁₀Ni₅₀ has the highest yield strength of 17 GPa, which is mainly due to NiTi₂ phase. Based on the tensile test results all cracks propagate along the brittle intermetallic compounds like NiTi₂ in the reaction layer the reduction of the strength of the joints and fracture behaviour upon propagation of the crack, which shows the morphological cleavage including facets characteristics.

Cu₆Sn₅ whiskers precipitated in Sn3.0Ag0.5Cu/Cu interconnection in concentrator silicon solar cells solder layer were found and investigated after reflow soldering and during aging. Ag₃Sn fibers can be observed around Cu₆Sn₅ whiskers in the matrix microstructure, which can play an active effect on the reliability of interconnection. Different morphologies of Cu₆Sn₅ whiskers can be observed, and hexagonal rod structure is the main morphology of Cu₆Sn₅ whiskers. A hollow structure can be observed in hexagonal Cu₆Sn₅ whiskers, and a screw dislocation mechanism was used to represent the Cu₆Sn₅ growth. Based on mechanical property testing and finite element simulation, Cu₆Sn₅ whiskers were regarded as having a negative effect on the durability of Sn3.0Ag0.5Cu/Cu interconnection in concentrator silicon solar cells solder layer.

In this study, 10%PTFE/PEEK blend were modified by potassium titanate whisker (PTW) and chopped glass fiber (GF), respectively. The blends were prepared by three-screw extruder. Through the investigation of thermal stability, tribological properties, mechanical properties and rheological behavior, the effects of reinforcing agents were determined. The results illustrated that the mechanical properties of 10%PTFE/PEEK blend can be dramatically improved by adding reinforcing agent of PTW or GF, and the reinforcing effect of GF was especially obvious. As for tribological properties, 1% addition was the best proportion. The friction coefficient and wear rate of the blend with 1% PTW were 0.283 and 4.97 × 10^-6 mm³/N · m, which decreased by 7.2% and 21% compared with those of the blend without reinforcing agent.

In this work, we designed a MEMS device which allows simultaneous direct measurement of mechanical properties during deformation under external stress and characterization of the evolution of microstructure of nanomaterials within a transmission electron microscope. This MEMS device makes it easy to establish the correlation between microstructure and mechanical properties of nanomaterials. The device uses piezoresistive sensors to qualitatively measure the force and displacement of nanomaterials, e.g., in wire and thin plate forms. The device has a theoretical displacement resolution of 0.19 nm and a force resolution of 2.1 μN. The device has a theoretical displacement range limit of 2.74 μm and a load range limit of 27.75 mN.

The thermal degradation behaviour of 10:90 and 90:10 blends of Polyethylene Terephthalate (PET) and petroleum coke has been investigated using mechanical alloying (milling) at 300 rpm and for periods up to 1-10 hours. Milled specimens were characterised using SEM and x-ray diffraction; their thermal degradation behaviour was investigated using thermo-gravimetric analyser (TGA) for temperatures up to 1200°C. Whereas PET specimens showed a tendency towards flattening out and increased surface area during collisions in ball mills, petroleum coke particles tended to break down into smaller particles. 10:90 and 90:10 blends of PET and coke showed significant microstructural evolution with increasing speeds and time including fracture, strain hardening and re-welding. X-ray diffraction results showed clear evidence for increasing amorphous component in petroleum coke without much influence on PET crystallinity. Thermo-gravimetric results showed a significant increase in the overall degradation and much higher weight losses associated with mechanical alloying. This study has shown that mechanical alloying could be used to modify the degradation behaviour of coke/plastic blends and corresponding yield during pyrolysis with implications for plastic waste management.

A heterograft copolymer with an alginate backbone, hetero-grafted by polymer pendant chains displaying different Lower Critical Solution Temperatures (LCSTs), combined with a pH-responsive Poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP-b-PEO) diblock copolymer forming micellar nanoparticles, was investigated in aqueous media at various pH. Due to its thermoresponsive side chains, the copolymer forms hydrogels with thermo–induced sol–gel transition, above a critical temperature, Tgel (thermo–thickening). However, by lowering pH of the medium in acidic regime, a remarkable increase of the elasticity of the formulation was observed. This effect was more pronounced in low temperatures (below Tgel) suggesting secondary physical crosslinking, which induces significant changes in the hydrogel thermoresponsiveness, transforming the sol–gel transition to soft gel–strong gel. Moreover, the onset of thermothickening shifted to lower temperatures followed by broadening of the transition zone, implying intermolecular interactions between the uncharged alginate backbone with the PNIPAM side chains, likely through H–bonding. The shear–thinning behavior of the soft gel in low temperatures provides injectability, which allows 3D–printing potential applications. Furthermore, the heterograft copolymer/nanoparticles composite hydrogel, encapsulating a model hydrophobic drug in the hydrophobic cores of the nanoparticles, was evaluated as pH-responsive drug delivery system. The presented tunable drug delivery system might be useful for biomedical potential applications.

This research is completed in development of researches devoted to relations between elastic modulus (MoE) and thermal expansivity (CTe) of different materials. This study experimentally confirmed the relation of MoE and CTe for thermosetting polymers and FRPs both under normal and heating temperatures. As the thermosetting polymers, the epoxy compositions were used and glass fiber and mineral additives for FRP. The experiment was based on dilatometric and elastic deformations’ testing. Also, the relaxation model of MoE/CTe was proposed, that is based on physical properties of polymers’ supramolecular structures. The comparative analyzing of MoE/CTes’ different models is done. The most accurate models are determined, and the relaxation model has demonstrated the high accuracy.

Growing concerns about the greenhouse effect, global warming, and adverse climate changes primarily stemming from carbon dioxide (CO2) emissions in traditional Portland cement (OPC) used in civil engineering construction, have prompted a shift toward eco-friendly alternatives like geopolymer cement (GPC). Over the last few decades, significant advancements have been made in developing environmentally sustainable pavement construction materials such as GPC to mitigate global CO2 emissions. The success of geopolymer cement (GPC) as an eco-friendly alternative to OPC has garnered attention for its potential to lower carbon emissions and enhance durability. This is attributed to the sustainable production method of GPC, where industrial cementitious waste materials (such as fly ash (FA), metakaolin (MK), mine tailings (MT), slag, etc.) are combined with an eco-friendly alkaline activator and water through the geopolymerization process. Numerous studies on geopolymer concrete indicate that, like OPC, GPC exhibits comparable mechanical properties, including strength, fire resistance, chemical resistance, and durability. This review explores the properties and applications of GPC as a sustainable material in pavement construction, exploring key studies and advancements in geopolymer technology, particularly its suitability for pavement applications. The assessment covers the mechanical properties, long-term performance, and environmental impact of geopolymer-based pavements, providing a comprehensive overview to inform policymakers, engineers, and researchers about the viability of geopolymer-based materials as a sustainable solution for modern pavement construction.

Wood is poised to become a material of choice for future construction. When appropriately managed, it is a renewable material with unique mechanical properties. Beyond its inherent sustainability, the use of wood has a crucial role in addressing climate change concerns due a significantly lower energy consumption and emissions during manufacturing and transportation, while simultaneously acting as a carbon sink. Thus, there has been a growing demand for hardwoods for structural applications, including Castanea sativa Mill., the focal point of this investigation. Albeit in a limited capacity, Eurocode 5-2 offers friction coefficients for softwoods, but it falls short for hardwoods which it is a gap to bridge with this research. These coefficients play a critical role in numerical simulations involving friction, enabling the optimization of joints and, by extension, the overall structural integrity. Test samples were evaluated at 18% moisture content, which is typical of Service Class 2, for various orientations of timber-to-timber and timber-to-steel friction. Considering previous friction coefficients at 12% moisture content, the linear variation was evaluated at an intermediate value of 15%. The results provide an experimental database for numerical simulations and highlight the influence of moisture content on the coefficients, which increase linearly along moisture percentages.

The mechanical pre-treatment constitutes an unavoidable pre-step prior to biofuels conversion. As the cost of this step is often underestimated, recently researchers have striven to identify and characterize the mechanical pre-treatment effects in terms of post-treatment physical characterization, derived improvement of enzymatic digestibility, and output yields. The status of existing mechanical pre-treatment techniques is reviewed by substrate’s typology for lignocellulose biomass, focusing on comminution techniques. Emphasis has been dedicated to the particle size achieved after treatment, crystallinity breakage and eventual inhibitory phenomena deriving from the application of particle size reduction, which are analysed and discussed.

In order to address the issues of weight, cost and sustainability issues associated with the application of glass fibre in structural composites, plant fibres are proposed as an alternative to reduce and replace the usage of glass fibres. Despite this, there is still a gap in comprehensive research on plant fibre composites, especially with regard to their durability in real structural applications. This research investigates the fatigue and impact properties of pultruded hybrid polyester composites reinforced with glass fibre and kenaf, tailored for structural applications. Utilising kenaf fibres in mat form, unidirectional glass fibre direct roving yarns and unsaturated polyester resin as key components, pultruded kenaf/glass hybrid profiles were meticulously fabricated. Comparative cost and weight analyses were conducted between pultruded hybrid and non-hybrid profiles. The study showed that the pultruded kenaf/glass alternative laminates exhibit commendable fatigue and impact resistance, making them suitable for use in moderately loaded structural applications. Moreover, the use of kenaf as a hybrid alternative shows significant cost and weight reductions. This research provides a basis for the development of sustainable and efficient structural materials and highlights the significant role of material design in shaping the future of engineering applications.

The current work shows the optimization in the preparation of nanosized titanium carbide (TiC) in-situ through mechanical alloying (MA). Metallic titanium (Ti) powders, along with two carbon sources, carbon nanotubes (CNTs), and stearic acid (SA), were used to reduce the particle size using a high-energy Spex800 mill. The combined use of 2 wt % of these carbon sources and n-heptane as a liquid process control agent (PCA) proved crucial in generating nanoscale powder composites through a simple and scalable synthesis process within a 4-hour timeframe. The use of 20 wt % of both carbon sources was compared to determine the ability of CNTs to form carbides and the decomposition of PCAs during mechanical milling. The result reveals structures like nanoblocks and nanolumps with and important size reduction. The structure and morphology of the composites and starting materials were evaluated through x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Compared to tin lead alloys, lead-free tin alloys have lower toxicity, making them more widely used. In this study, Sn-20Bi-0.3Al-xY solders alloys were prepared. The effects of the addition of Y on its microstructure, micro-hardness, wettability and mechanical properties was investigated. The result showed that the addition of Y had significant effect on the refinement of Sn-20Bi-0.3Al-xY. From the spreading tests results, Y increased the wettability of the solders, however when the fraction of Y gradually increased, the wettability reduced. The ultimate tensile and hardness of Sn-20Bi-0.3Al-xY solders alloys were increased as the content of Y increasing.

It is generally accepted that the human abdominal wall is comprised of skin, subcutaneous tissues, muscles and their aponeuroses, and the parietal peritoneum. Understanding these layers and their mechanical properties provides valuable information to those designing procedural skills trainers, supporting surgical procedures (hernia repair), and engineering-based work (in silico simulation). However, there is little literature available on the mechanical properties of the abdominal wall in layers or as a composite. This work characterizes the tensile properties of the human abdominal wall by layer and as a partial composite. Tissues were collected from fresh-never-frozen and fresh-frozen cadavers and tested in uniaxial tension at a rate of 5 mm/min until failure. Stress-strain curves were created for each sample, and the values for elastic moduli, ultimate tensile strength, and strain at failure were obtained. The experimental outcomes from this study demonstrated variation of tensile properties within and between tissues. The data also suggest that the tensile properties of composite abdominal walls are not additive. Ultimately, this body of work contributes to a deeper comprehension of these mechanical properties and will serve to enhance patient care, refine surgical interventions, and assist with more sophisticated engineering solutions.

Abstract: The chemical mechanical polishing (CMP) has been widely used for surface modification of critical materials and components and provided global planarization of topography with a low post-planarization slope high quality and efficiency. The colloidal silica slurries play an important role in the finishing processes of optical components. Monodisperse mesoporous silica nanospheres were synthesized with different surfactant by Stöber method. Their architectural features and texture parameters were characterized by XRD, FTIR, N2 adsorption–desorption isotherms, SEM, XPS, and TGA techniques. The spherical SiO2 products presented with the controllable 50-150 nm particle size and distribution. The AFM micrographs reveal that flat and smooth surfaces without distinct scratches residual particles are achieved by using the as-obtained composite particles as abrasives[The particle size of SiO2 slurry plays a critical role in the chemical-mechanical polishing process.

The dolomite dust-emulsified asphalt composite with excellent mechanical properties was successfully prepared using alkali activation. The effects of different alkali concentrations and emulsified asphalt contents on the mechanical properties of the materials were studied. The mechanical properties and microstructure of the composites were analyzed using compressive strength tests, bending strength tests, and SEM characterization. The experimental results show that the specimens have excellent mechanical properties: the 7-day compressive strength can reach 76.67 MPa, and the bending strength is about twice that of silicate-based geopolymer-emulsified asphalt composite. With an increase in emulsified asphalt content, the compressive strength of the samples decreases, while the bending strength increases first and then decreases. When the emulsified asphalt content is 1%, the bending strength of the sample is up to 28.81 MPa, which is 25% higher than that of the sample without emulsified asphalt. This indicates that an appropriate emulsified asphalt content can play a toughening role in the system, providing a new idea for designing high-toughness alkali-activated materials.

The impact induced by cavitation bubble collapse can be utilized for mechanical surface treatment to improve fatigue properties of metals including additive manufactured metallic materials. A peening method using cavitation impact induced by a pulsed laser is called “laser cavitation peening (LCP)”. Normally, a Q-switched Nd:YAG laser, whose pulse width is a few nanoseconds, is used for LCP, which improves the fatigue strength. The problem with LCP is that the processing time is too slow. If a laser pulse whose pulse width is a few hundred microseconds can be utilized for LCP, the repetition frequency can be increased drastically using other types of laser systems such as a fiber laser. In the present paper, in order to reveal the possibility of LCP using a pulsed laser width of a few hundred microseconds, the use of LCP with a normal-oscillation Nd:YAG laser (pulse width ≈ 200 us) was investigated. It is demonstrated that LCP with the normal-oscillation Nd:YAG laser produced curvature in an aluminum alloy plate.

Abstract: To compare the use of variable mechanical ventilation with conventional mechanical ventilation in porcine model of ARDS. Methods: Animals were divided into two groups (n = 6), conventional ventilation and variable ventilation with bi-oscillatory PEEP. For induction of ARDS, intravenous oleic acid was used until a P/F ratio of 200 to 300 mmHg. The animals were ventilated with pressure control, FiO2 1.0, inspiration-expiration ratio = 1:2, tidal volume 6 ml/kg with the initial respiratory rate adjusted to maintain an end tidal CO2 tension of 35 to 45 mmHg. Variable ventilation was characterized by the oscillation of PEEP from 5 to 10 cmH2O every 4 respiratory cycles, in convencional ventilation group PEEP was set from 5 cmH2O. Ventilatory, hemodynamic parameters, oxidative stress, antioxidant enzymes, Interleukin 8 (IL8) and 17-a (IL17a) and histological analyzes were evaluated; Results: The use of BiPEEP demonstrated improvement in lung compliance and PaO2 in relation to control. The levels of oxidative stress and antioxidant enzymes showed no significant difference. There was no difference in IL17a between groups. In IL8 there was a significant increase in the lung base of control in relation to BiPEEP, and a reduction in the apex of BiPEEP in relation to control. The control group showed changes in lung morphology characterized by cellular infiltrates, a thickening of the alveolar septae and atelectasis, which were attenuated in BiPEEP group; (4) Conclusions: The use of variable ventilation with bi-oscillatory level of PEEP demonstrates a potential ventilatory strategy in an experimental model of ARDS.

Advanced coatings are essential to modern technologies, as they optimise surface characteristics for different application scenarios. Transparent and self-cleaning coatings are increasingly used as protective coatings for various applications, such as foldable touchscreens, windows, and solar panels. Moreover, incorporating other functionalities such as high hardness, wear resistance, and flexibility into transparent and self-cleaning coatings is important for broadening the use cases. Although many kinds of multifunctional coatings have been developed, it is still difficult to embody several properties in one coating adequately, as some properties, such as hardness and flexibility, are inherently contrastive. This review first describes basic principles, including wetting ability, photocatalytic reactions, photo-induced hydrophilic phenomena, and the implication of self-cleaning. The desired properties of multifunctional coatings are then listed, and methods for evaluating different properties are used. Recent progress in various preparation methods for multifunctional coatings, including the sol-gel, dip/spin, and chemical vapour deposition (CVD) methods, are also presented. Magnetron sputtering (MS) technology is widely used in coating preparation. Compared with chemosynthesis and CVD, MS is time-saving, suitable for industrial production, and environmentally friendly. Coatings prepared by MS usually possess excellent mechanical properties. Thus, we highlight the current research status of MS technology in multifunctional coating preparation. Moreover, according to the multilayer design structure of coatings, their optical and mechanical properties and self-cleaning ability can be controlled by combining the characteristics of different materials. Finally, combining photocatalytic materials such as TiO2 with other materials through a multilayer structure to obtain a multifunctional coating with excellent overall properties is discussed.

Hydrogel-based wearable electrochemical biosensors (HWEBs) are emerging biomedical devices that have recently received immense interest. The exceptional properties of HWEBs include excellent biocompatibility with hydrophilic nature, high porosity, tailorable permeability, the capability of reliable and accurate detection of disease biomarkers, suitable device-human interface, facile adjustability, and stimuli-responsive to the nanofiller materials. Although the biomimetic three-dimensional hydrogels can immobilize bioreceptors, such as enzymes and aptamers, without any loss in their activities. However, most HWEBs suffer from low mechanical strength and electrical conductivity. Many studies have been performed on emerging electroactive nanofillers, including biomacromolecules, carbon-based materials, and inorganic and organic nanomaterials, to tackle these issues. Non-conductive hydrogels and even conductive hydrogels may be modified by nanofillers as well as redox species. All these modifications have led to the design and development of efficient nanocomposites as electrochemical biosensors. In this review, both conductive-based and non-conductive-based hydrogels derived from natural and synthetic polymers are systematically reviewed. The main synthesis methods and characterization techniques are addressed. The mechanical properties and electrochemical behavior of HWEBs are discussed in detail. Finally, the prospects and potential applications of HWEBs in biosensing, healthcare monitoring, and clinical diagnostics are highlighted.

This study investigated the impact of boron and copper on the microstructure and mechanical properties of Spheroidal graphite Cast Iron (SCI). The addition of boron increased the ferrite content, while copper increased the stability of pearlite. The interaction between boron and copper significantly increased the ferrite content. Differential Scanning Calorimetry (DSC) revealed that boron decreased the enthalpy change of the α + Fe3C -> γ transformation and increased the enthalpy change of the α -> γ transformation. The addition of boron and copper reduced the tensile and yield strength but increased elongation and impact energy. The findings provide valuable insights into the effect of boron and copper on SCI, facilitating the design and development of high-performance SCI materials.

This paper mainly used database technology, machine learning, thermodynamic calculation, experimental verification, etc., on integrated computational materials engineering. The interaction between different alloying elements and the strengthening effect of precipitated phases are investigated mainly for martensitic ageing steels. Modelling and parameter optimization were performed by machine learning, and the highest prediction accuracy was 98.58%. Investigated the influence of composition fluctuation on performance and correlation tests to analyze the influence of elements from multiple perspectives. Furthermore, screen out the three-component composition process parameters with composition and performance with high contrast. Thermodynamic calculations studied the effect of alloying element content on the nano-precipitation phase, Laves phase, and austenite in the material. The heat treatment process parameters of the new steel grade were also developed based on the phase diagram. A new type of martensitic ageing steel was prepared by selected vacuum arc melting. The sample with the highest overall mechanical properties had a yield strength of 1887 MPa, a tensile strength of 1907 MPa, and a hardness of 58 HRC. The sample with the highest plasticity had an elongation of 7.8%. The machine learning process for the accelerated design of new ultra-high tensile steels was found to be generalizable and reliable.

In order to produce nanostructured Ti0.9Cr0.1C powders, an elemental powder mixture of titanium, chromium, and graphite is milled in this work using a high-energy ball mill for various milling times. Microstructural characteristics such as crystallite size, microstrain, lattice parameter, and dislocation density are determined using X-ray diffraction (XRD). Mechanical alloying successfully produced nanocrystalline (Ti,Cr)C with an average crystallite size of 11 nm. This size of the crystallites is also directly verified using transmission electron microscopy (TEM). Scanning electron microscopy (SEM) was used to investigate the morphology of the samples. The novelty of this work is advancing the scientific understanding of the effect of milling time on the particle size distribution and crystalline structure, and also understanding the effect of the spark plasma sintering on the different properties of the bulks. Densified cermet samples were produced from the nanocrystalline powders, milled for 5, 10 and 20 hours by SPS process at 1800 degrees for 5 min under a pressure of 80 MPa. Phase changes of the produced cermets were examined according to XRD, SEM/EDX analyses. Significant amounts of Cr and Fe elements were detected, especially in the 20 h milled cermet. The bulk forms of the milled powders for 5 and 20 h had a relative density of 98.43 and 98.51 %, respectively. However, 5 h milled cermet had 93.3 HRA because of the more homogeneous distribution of the (Ti,Cr)C phase, the low iron content and high relative density. According to the 0.0011 mm/year corrosion rate, and 371.68 kΩ*cm2 charge transfer resistance obtained from the potentiodynamic polarization and EIS tests, the 20 h cermet was the specimen with the highest corrosion resistance.

The solid-state welding method known as friction stir welding (FSW) bonds two metallic work parts, whether the same or different, by plastically deforming the base metal. The frictional resistance between both metallic work pieces causes them to produce heat, which produces plastic deformation and welds them. However, the weldability and strength of FSW joints mainly depend on the FSW parameters. This review work highlights the previous research work on the FSW parameters and their effects on the weldability and quality of the aluminum alloys joined with similar and dissimilar metals through the FSW method. About 150 research studies were systematically reviewed, and the articles included data from peer-reviewed journals. It has been concluded that the key parameters, including welding speed, “rotational speed”, “plunge depth”, “spindle torque”, “shoulder design”, “base material”, “pin profile” and “tool type", significantly affect the weldability of the aluminum joint through the FSW method. Also, the selection of these parameters is important and fundamental as they directly affect the joint. It is recommended that future work focus on FSW for aluminum. Among these, the most essential is the application of artificial intelligence (AI) techniques to select the optimum FSW parameters for aluminum welding.

Time and cost-efficient techniques are essential to avoid extra conventional experimental studies with large date-set to characterize the mechanical properties of composite materials. Correlation between the structural performance and mechanical properties could be captured through the efficient predictive models. Several ensembled Machine Learning (ML) methods were implemented in this study, to materially characterize carbon nanotube (CNT)-reinforced cement-based composites. Proposed models were compared with each other to represent the accuracy of each method. The Flexural and Compressive Strength (target values) of CNT reinforced composites were predicted based on the data-rich framework provided in previous experimental investigations. These data were utilized for training of the proposed models by employing SciKit-Learn library in Python, followed by hyper-parameter tuning and k-fold cross-validation method for obtaining an efficient model to predict the target values. Random Forest (RF) and Gradient Boosting Machine (GBM) were developed for this purpose. The findings of this study would be useful for prospective composite designers in case of sufficient experimental data availability for ML model training.

The paper contains the results of the 100-hour test campaign of the Additive Manufactured (AM) spare part (retainer – slipper) dedicated for an exact axial piston pump. The material of the retainer-slipper has been identified by using energy dispersive spectroscopy and replaced by other – with similar material properties as the original one. The obtained spare part had been subjected to only one postprocessing type (sandblasting) to analyze the influence of the rough part after the AM process. The whole test campaign has been divided into stages, where after each stage microscopic measurements have been made. During microscopical investigation roughness and geometrical measurements were conducted. The results revealed that it is possible to replace parts in hydraulic pumps with the use of AM. 100-hour test campaign caused about 500% increase in the surface roughness of the pump’s original part which was cooperated with the AM spare retainer-slipper, without any damages to the test system.

Closed timelike curves (CTCs), non-intuitive theoretical solutions of general relativity field equations can be modelled in quantum mechanics in a way, known as Deutsch-CTCs, to circumvent one of their most paradoxical implications, namely, the so-called grandfather paradox. An outstanding theoretical result of this model is the demonstration that in the presence of a Deutsch-CTC a classical computer would be computationally equivalent to a quantum computer. In the present study, the possible implications of such a striking result for the foundations of quantum mechanics and the connections between classicality and quantumness are explored. To this purpose, a model for fundamental particles that interact in physical space exchanging carriers of momentum and energy is considered. Every particle is then supplemented with an information space in which a probabilistic classical Turing machine is stored. It is analysed whether, through the action of Darwinian evolution, both a classical algorithm coding the rules of quantum mechanics and an anticipation module might plausibly be developed on the information space from initial random behaviour. The simulation of a CTC on the information space of the particle by means of the anticipation module would imply that fundamental particles, which do not possess direct intrinsic quantum features from first principles in this information-theoretic Darwinian approach, could however generate quantum emergent behaviour in real time as a consequence of Darwinian evolution acting on information-theoretic physical systems.

The petrographic and petrophysical characteristics of three varieties of ignimbrites used in the architectural heritage of Arequipa (southwest Peru) are analyzed. The modal classification QAFP and TAS diagram discriminate their dacitic nature. Mercury injection porometry revealed very high porosity: 46.5% for white and beige ignimbrites and 35.5% for the pink variety. Ignimbrites contain intrusions of vulcanodetrital fragments and vacuoles that influence their predominantly non-linear mechanical behavior. Results of water absorption by capillarity (C) and ultrasound pulse velocity (UPV) demonstrated a slight anisotropy for the beige variety and near isotropy for white and pink ignimbrites, which justify the randomness of the application of the ashlars in the masonry and in the selection of the faces to carve. Surfaces with hollows in the white and beige ignimbrites are the result of the erosion of the acicular pumice that fills the vacuoles.

The concern about consuming eco-friendly products has motivated research in the development of new materials. Therefore, films based on natural polymers have been used to replace traditional polymers. This study consists of a production of films based on gelatin reinforced with black pepper essential oil-loaded nanoemulsions and Cloisite Na⁺. The films were characterized by water vapor permeability, mechanical and thermal properties, surface contact angle, X-ray diffraction and scanning electron microscopy. It was observed that the films containing the nanoemulsion have higher permeability values and an increase in their mechanical resistance. The addition of nanoclay contributed to an increase in the surface hydrophobicity of the film and an increase in the tensile strength at break by about 150%. The addition of essential oil nanoemulsions led to an increase in thermal stability. The presence of clay dispersion contributed to the formation of a surface that was slightly rougher and grainier. The addition of the black pepper essential oil nanoemulsion resulted in an increase in porosity of the gelatin matrix. Through X-ray diffraction analysis, it was possible to conclude that both the polymeric gelatin matrix and the essential oils nanoemulsion are intercalated with the clay dispersion.

A better understanding of diseases progress in tissues vest on the accurate understanding of tissues under mechanical loading. Also, development of therapies for injuries may depend on the available mechanical data for soft tissues. In this study, the raw data of biaxial tensile testing of sclera soft tissue is presented in this paper. Biaxial mechanical testing of soft tissues presents details understanding of how soft tissues behave when compared to uniaxial testing. Biomechanical properties of soft tissues are vital in the development of accurate computational models. Reliable computational models of studying mechanisms of diseases depends mainly on the accurate and more details mechanical behavior of soft tissues. These accurate and detailed computational models may be utilized to further develop the understanding and therapies of various diseases. The mechanical tensile testing was conducted on the passive sheep sclera. Engineering stress vs strain of several samples of the sheep sclera are further presented determined from force and displacement experimental data. The goal of this paper is to make available biaxial data of sheep sclera soft tissue that can be further utilized.

The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by the objective, and therefore by the type of technique applied to achieve it. To attain the best results in terms of rock breakage and respect of the final profile, it’s important to evaluate the excavation specific energy and its optimization. This research focuses on evaluating the effects of different techniques on the quality of final walls in open-pit and underground operations. Different geometries and configurations can be applied to both quarrying and tunnelling blasts. The research is aimed to push contour blasts to their limits, and the main aspects are discussed in order to improve the blast parameters in the daily practice.

Aim: The aim of this study was to estimate the number of nurses who independently care for pa-tients with severe respiratory failure receiving mechanical ventilation (MV) or veno-venous ex-tracorporeal membrane oxygenation (VV-ECMO). Additionally, the study analyzed the actual role of nurses in the treatment of patients with MV and VV-ECMO. Methods: We conducted a cross-sectional study using postal surveys. The study included 725 Japanese intensive care units (ICUs). Descriptive statistics were conducted. Results: Among the 725 ICUs, we obtained 302 re-sponses (41.7%) and analyzed 282 responses. The median number of nurses per bed was 3.25. The median proportion of nurses who independently cared for patients with MV was 60% [IQR: 42.3-77.3]. The median proportion of nurses who independently cared for patients with VV-ECMO was 46.9 (35.7-63.3%) in the ICU experiencing VV-ECMO use. Concerning task-sharing, 33.8% of ICUs and nurses did not facilitate weaning from MV. Nurses always ti-trated sedatives in 44.5% of ICUs. Conclusion: Nurse staffing might be inadequate in all ICUs, es-pecially for severe respiratory failure. The proportion of competent nurses for caring for severe respiratory failure in ICUs should be considered when determining the work force of nurses.

Shape-memory hydrogels (SMH) are as multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks gelatin chains may form triple helices, which can act as temporary netpoints in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with OEG α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27-23 kPa and Young’s moduli of 215-360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied e.g. as self-anchoring devices mechanically resembling the extracellular matrix.

Fired bricks have shown tremendous potential as a construction material due to their properties. However, their use required some specifications in terms of quality, resistance, and durability. In developing countries, the lack of tools to make test specimens leads to many defects in these brick specimens responsible for low durability and weak precision during mechanical tests and shrinkage. In this study, a simple and traditional method of making test bricks is presented. This simple method allows the production of bricks with the required properties. This method is especially efficient for a firm or semi-soft pastes consistency. The handmade pastes do not stick into the walls of the mold like the case of steel molds and it gives specimens with standard shape, smooth surface, and sharp edges. The resulting fired bricks exhibit high mechanical strength comparable and even better than those of conventional methods.

The effect of rare earth Pr6O11 on the microstructure and mechanical properties of high-strength steel weld metal was investigated by optical microscopy, scanning electron microscopy and mechanical testing. Three different contents of Pr6O11 were added to the flux-cored wires. The results showed that the addition of 1% Pr6O11 can promote the refinement and spheroidization of inclusions, refine the grains, form acicular ferrites, and significantly improve the toughness of weld metal. The addition of Pr6O11 promoted the formation of rare earth composite inclusions and acicular ferrites in the weld metal, refined the lath microstructure, inhibited the formation of martensite and bainite. The crack formation mode changed from the boundary cracking of the bainite clusters caused by the surface shear stress to the surface shear stress-induced decohesion of inclusion. However, excessive addition of Pr6O11 will reduce the number of inclusion nucleation and deteriorate the mechanical properties. The wire No.2 with 1% Pr6O11 had the good comprehensive mechanical properties, and the corresponding values were 835MPa of tensile strength and 72 J of impact toughness. These findings suggest that the control of Pr6O11 can be an effective way to improve the impact toughness of weld metal.

The effect of Pr6O11 on the microstructure and mechanical properties of high-strength steel weld metal was investigated by optical microscopy, scanning electron microscopy and mechanical testing. Three different contents of Pr6O11 were added to the flux-cored wires. The results demonstrate that the addition of 1% Pr6O11 can promote the refinement and spheroidization of inclusions, refine the grains, form acicular ferrites in the weld metal, and significantly improve the toughness. The addition of Pr6O11 promoted the formation of rare earth composite inclusions and acicular ferrites in the weld metal, refined the lath microstructure, inhibited the formation of martensite and bainite. The crack formation mode changed from the boundary cracking of the bainite clusters caused by the surface shear stress to the surface shear stress-induced decohesion of inclusion. Excessive addition of Pr6O11 will reduce the number of inclusion nucleation and deteriorate the mechanical properties. The wire No.2 with 1% Pr6O11 had the good comprehensive mechanical properties.

Regional mechanics of the heart is vital in the development of accurate computational models for the pursuit of relevant therapies. Challenges related to heart dysfunctioning are the most important sources of mortality in the world. For example, myocardial infarction (MI) is the foremost killer in sub-Saharan African countries. Mechanical characterisation plays an important role in achieving accurate material behaviour. Material behaviour and constitutive modelling are essential for accurate development of computational models. In most cases previously, the mechanical properties of the heart myocardium were assumed to be homogeneous. The main objective of this paper is to determine the mechanical material properties of healthy porcine myocardium in three regions, namely left ventricle (LV), mid-wall/interventricular septum (MDW) and right ventricle (RV). The biomechanical properties of the pig heart RV, LV and MDW were characterised using biaxial testing. The biaxial tests show the pig heart myocardium behaves non-linearly, heterogeneously and anisotropically. In this study, it was shown that RV, LV and MDW may exhibit slightly different mechanical properties. Data presented here may be helpful in regional tissue mechanics, especially for the understanding of various heart diseases and development of new therapies.

We demonstrate high quality (intrinsic Q factor ~2.8×106) racetrack microresonators fabricated on lithium niobate (LN) thin film with a free spectral range (FSR) of ~86.38 pm. By integrating microelectrodes alongside the two straight arms of the racetrack resonator, the resonance wavelength around the 1550 nm can be red shifted by 92 pm when the electric voltage is raised from -100 V to 100 V. The microresonators of the tuning range spanning over a full FSR is fabricated using photolithography assisted chemo-mechanical etching (photolithography assisted chemo-mechanical etching, PLACE).

Background: The main factors to influence on the stroking performance of club head are alloy and spring-like effect. Design the structure of new club face to create the fairway wood which can show best stroking feeling and let driving distance become longer. Purpose: The club face of fairway wood is processed through the iron alloy heating procedure and CNC to innovate the club head with high spring-like effect (characteristic time). Method: (1) Use 455 stainless steel processed by heating and aging treatment, to do the analysis on microstructure and mechanical properties. (2) Through CNC to design seven different patterns for the back of club face, each pattern for three club head. The total amount is twenty-one. (3) Make finished product be test the characteristic time and the ability of strike by the practical measurement. (4) To analyze after the compare between three-way ANOVA and LSD. Results: After 455 stainless steel was heated in procedure S850℃-A550℃, mechanical properties became superior and had the better malleability, it is suitable for developing the club face of high spring-like effect. Before and after grinding among three-way ANOVA (pattern*thickness*place), did not achieve the significant level on the figure of characteristic time. Through two-way ANOVA (pattern*place and thickness*place), showed the significant deviation before and after grinding. After doing the crash test by 45m/s, all the results can reach the higher limited standard. Summary: 455 stainless steel was designed with the different club face’s thicknesses of fairway wood can make spring-like effect achieve high characteristic time. The much thinner club face let the characteristic time perform highly. But there was no obvious effects from the patterns of the back club face.

Mortarless refractory masonry structures are widely used in the steel industry for the linings of many high-temperature industrial applications including steel ladle. The design and the optimization of these components require accurate numerical models that consider the presence of joints as well as joints closure and opening due to cyclic heating and cooling. The present work reports on the formulation, numerical implementation, validation, and application of homogenized numerical models for simulation of refractory masonry structures with dry joints. The validated constitutive model has been used to simulate a steel ladle and to analyze its transient thermomechanical behavior during a typical thermal cycle of steel ladle. 3D solution domain, enhanced thermal and mechanical boundary conditions have been used. Parametric studies to investigate the impact of joints thickness on the thermomechanical response of the ladle have been carried out. The results clearly demonstrate that the thermomechanical behavior of mortarless masonry is orthotropic nonlinear due to gradual closure and reopening of joints with the increase and decrease of temperature. Also, resulting thermal stresses increase with the increase of temperature and decrease with the increase of joints thickness.

In this paper, the effect of preheating on the mechanical properties and micro structure of similar friction stir welded AA6061 aluminum alloys sheets was investigated. Aluminum alloy 6061 sheets with a thickness of 5 mm and threaded cylindrical pins were used. Rotation and traverse speeds were 1200 rpm and 75 mm/min, respectively. The results of tensile tests performed on the welded samples showed that compared to the non-preheated samples, preheating had increased the strength and elongation of the joints by 58% and 46%, respectively. In the present study, during the welding process preheating cause emerged heat with lower slope from stir zone. This phenomenon may result in Increase the deformation resistance of material and consequently decrease of grain size. This grain refinement can improve the mechanical properties of welds. Accordingly, hardness and strength of the material will be increased.

The effect of reprocessing on the quasi-static uniaxial tensile behavior of two commercial polypropylene (PP) based composites is experimentally investigated and modeled. In particular, the studied materials consist of an unfilled high-impact PP and a talc-filled high-impact PP. These PP composites are subjected to repeated processing cycles including a grinding step and an extrusion step to simulate recycling at the laboratory level, the selected reprocessing numbers for this study being 0, 3, 6, 9 and 12. Because the repeated reprocessing leads to thermo-mechanical degradation by chain scission mechanisms, the tensile behavior of the two materials exhibits a continuous decrease of elastic modulus and failure strain with increasing number of reprocessing. A physically consistent three-dimensional constitutive model is used to predict the tensile response of non-recycled materials with strain rate dependence. For the recycled materials, the reprocessing effect is accounted by incorporating the reprocessing sensitive coefficient into the constitutive model for Young’s modulus, failure strain, softening and hardening equations. Our predictions of true stress - true strain curves for non-recycled and recycled 108MF97 and 7510 are in a good agreement with experimental data.

Polymer flooding is an established enhanced oil recovery (EOR) method, still many aspects of polymer flooding are not well understood. This study investigates the influence of mechanical degradation on flow properties of polymers in porous media. Mechanical degradation due to high shear forces may occur in the injection well and at the entrance to the porous media. The polymers that give high viscosity yields at a sustainable economic cost are typically large, MW > 10 MDa, and have wide molecular weight distributions. Both MW and the distributions are altered by mechanical degradation, leading to changes in the flow rheology of the polymer. The polymer solutions were subjected to different degrees of pre-shearing and pre-filtering before injected into Bentheimer outcrop sandstone cores. Rheology studies of injected and produced polymer solutions were performed and interpreted together with in-situ rheology data. The core floods showed a predominant shear thickening behavior at high flow velocities which is due to successive contraction/expansion flow in pores. When pre-sheared, shear thickening was reduced but with no significant reduction in in-situ viscosity at lower flow rates. This may be explained by reduction in the extensional viscosity. Furthermore, the results show that successive degradation occurred which suggests that the assumption of the highest point of shear which determines mechanical degradation in a porous media does not hold for all field relevant conditions.

High-performance poly(1,4-butylene terephthalate (PBT) nanocomposites have been developed via the consideration of phosphorus-containing agents and amino-carbon nanotube (A-CNT). One-pot functionalization method has been adopted to prepare functionalized CNTs via the reaction between A-CNT and different oxidation state phosphorus-containing agents, including chlorodiphenylphosphine (DPP-Cl), diphenylphosphinic chloride (DPP(O)-Cl), and diphenyl phosphoryl chloride (DPP(O3)-Cl). These functionalized CNTs, DPP(Ox)-A-CNTs (x = 0, 1, 3), were respectively mixed with PBT to obtain the CNTs-based polymer nanocomposites through a melt blending method. SEM observations demonstrated that DPP(Ox)-A-CNT nano-additives were homogeneously distributed within PBT matrix compared to A-CNT. The incorporation of DPP(Ox)-A-CNT improved the thermal stability of PBT. Moreover, PBT/DPP(O3)-A-CNT showed the highest crystallization temperature and tensile strength, due to the superior dispersion and interfacial interactions between DPP(O3)-A-CNT and PBT. PBT/DPP(O)-A-CNT exhibited the best flame retardancy resulting from the excellent carbonization effect. The radicals generated from decomposed polymer were effectively trapped by DPP(O)-A-CNT, leading to the reduction of heat release rate, smoke production rate, carbon dioxide and carbon monoxide release during cone calorimeter tests.

We focus on macromolecules which are modelled as sequentially growing dual scale-free networks. The dual networks are built by replacing star-like units of the primal treelike scale-free networks through rings, which are then transformed in a small-world manner up to the complete graphs. In this respect, the parameter γ describing the degree distribution in the primal treelike scale-free networks regulates the size of the dual units. The transition towards the networks of complete graphs is controlled by the probability p of adding link between non-neighbouring nodes of the same initial ring. The relaxation dynamics of the polymer networks is studied in the framework of generalized Gaussian structures by using the full eigenvalue spectrum of the Laplacian matrix. The dynamical quantities on which we focus here are the averaged monomer displacement and the mechanical relaxation moduli. For several intermediate values of the parameter’s set (γ, p) we encounter for these dynamical properties regions of constant in-between slope.