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Over the past 150 years, our ability to produce and transform engineered materials has been responsible for our current high standards of living, especially in developed economies. However, we must carefully think of the effects our addiction to creating and using materials at this fast rate will have on the future generations. The way we currently make and use materials detrimentally affects the planet Earth, creating many severe environmental problems. It affects the next generations by putting in danger the future of the economy, energy, and climate. We are at the point where something must drastically change, and it must change now. We must create more sustainable materials alternatives using natural raw materials and inspiration from nature while making sure not to deplete important resources, i.e. in competition with the food chain supply. We must use less materials, eliminate the use of toxic materials and create a circular materials economy where reuse and recycle are priorities. We must develop sustainable methods for materials recycling and encourage design for disassembly. We must look across the whole materials life cycle from raw resources till end of life and apply thorough life cycle assessments (LCAs) based on reliable and relevant data to quantify sustainability. We need to seriously start thinking of where our future materials will come from and how could we track them, given that we are confronted with resource scarcity and geographical constrains. This is particularly important for the development of new and sustainable energy technologies, key to our transition to net zero. Currently ‘critical materials’ are central components of sustainable energy systems because they are the best performing. A few examples include the permanent magnets based on rare earth metals (Dy, Nd, Pr) used in wind turbines, Li and Co in Li-ion batteries, Pt and Ir in fuel cells and electrolysers, Si in solar cells just to mention a few. These materials are classified as ‘critical’ by the European Union and Department of Energy. Except in sustainable energy, materials are also key components in packaging, construction, and textile industry along with many other industrial sectors. This roadmap authored by prominent researchers working across disciplines in the very important field of sustainable materials is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the sustainable materials community. In compiling this roadmap, we hope to aid the development of the wider sustainable materials research community, providing a guide for academia, industry, government, and funding agencies in this critically important and rapidly developing research space which is key to future sustainability., The authors would like to thank The Faraday Institution ReLiB Project Grant Numbers FIRG005 and FIRG006, the UKRI Interdisciplinary Circular Economy Centre for Technology Metals (Met4Tech) Grant No. EP/V011855/1 and the EPSRC Critical Elements and Materials Network (CREAM) EP/R020140/1 for providing financial assistance for this research.

Timescales of polyamide 6 melt-shaping technologies, relative to the dynamics of conformational rearrangements upon crystallization, challenge the formation of the most thermodynamically favorable chain packing and thus optimum performance. In this publication, we make use of the mediation of hydrogen bonding by water molecules in the superheated state of water, i.e., above 100 °C in a closed environment, in the structural refinement of polyamide 6 for enhanced thermomechanical performance. The paper addresses dissolution and (re)crystallization of different polyamide 6 polymorphs in the superheated state of water by time-resolved simultaneous small- and wide-angle X-ray scattering and solid-state 1H NMR spectroscopy and the effect on mechanical properties. The experiments reveal that upon heating in the superheated state of water, the pseudo-hexagonal phase dissolves at relatively low temperature and instantly crystallizes in a defected monoclinic phase that successively refines to a perfected monoclinic structure. The dissolution temperature of the pseudo-hexagonal phase of polyamide 6 is found to be dependent on the degree of crystal perfection originating from conformational disorder and misalignment of hydrogen bonding in the lattice, retrospectively, to the Brill transition temperature. The perfected monoclinic phase below the dissolution temperature can be preserved upon cooling but is plasticized by hydration of the amide moieties in the crystalline phase. The removal of water from the hydrated crystals, in the proximity of Brill transition temperature, strengthening the hydrogen bonding, occurs. Retrospectively, the most thermodynamically stable crystallographic phase is preserved and renders an increase in mechanical properties and dimensional stability of the product. The insight obtained on the influence of superheated water on the structural refinement of imperfected crystallographic states assists in polyamide 6 postprocessing strategies for enhanced performance.

The metallic glasses are known as amorphous and metastable materials. These materials have superior mechanical properties over crystalline materials with the same chemistry. Continuous efforts were made to improve the properties of metallic glass. The severe plastic deformation (SPD) method is used to improve the ductility of the glass. SPD causes the deformation at the atomic level in the disordered structure of the glass. Many methods are reported, such as cryogenic cycling, high-pressure torsion, and equal channel angular pressing, which are used for the SPD. In recent works on nanostructured metallic glasses, it has been evidenced that some properties, for example, mechanical, thermal, and magnetic, have improved compared to the bulk metallic glass. This paper has reviewed the recent progress in the SPD of the bulk and nanostructured metallic glasses. Different methods for the SPD have been addressed here. The effect of SPD on the properties of metallic glass is deliberated in this paper. Moreover, the challenging tasks of deformation occurrence in the glass and its characterization were considered, trying to develop a sound understanding of SPD in bulk and nanostructured metallic glasses.

Introduction Malalignment of the Total Ankle Replacement (TAR) has often been postulated as the main reason for the high incidence of TAR failure. As the ankle joint has a small contact area, stresses are typically high, and malalignment may lead to non-homogeneous stress distributions, including stress peaks that may initiate failure. This study aims to elucidate the effect of TAR malalignment on the contact stresses on the bone-implant interface, thereby gaining more understanding of the potential role of malalignment in TAR failure. Methods Finite Element (FE) models of the neutrally aligned as well as malaligned CCI (Ceramic Coated Implant) Evolution TAR implant (Van Straten Medical) were developed. The CCI components were virtually inserted in a generic three-dimensional (3D) reconstruction of the tibia and talus. The tibial and talar TAR components were placed in neutral alignment and in 5° and 10° varus, valgus, anterior and posterior malalignment. Loading conditions of the terminal stance phase of the gait cycle were applied. Peak contact pressure and shear stress at the bone-implant interface were simulated and stress distributions on the bone-implant interface were visualized. Results In the neutral position, a peak contact pressure and shear stress of respectively 98.4 MPa and 31.9 MPa were found on the tibial bone-implant interface. For the talar bone-implant interface, this was respectively 68.2 MPa and 39.0 MPa. TAR malalignment increases peak contact pressure and shear stress on the bone-implant interface. The highest peak contact pressure of 177 MPa was found for the 10° valgus malaligned tibial component, and the highest shear stress of 98.5 MPa was found for the 10° posterior malaligned talar model. High contact stresses were mainly located at the edges of the bone-implant interface and the fixation pegs of the talar component. Conclusions The current study demonstrates that TAR malalignment leads to increased peak stresses. High peak stresses could contribute to bone damage and subsequently reduced implant fixation, micromotion, and loosening. Further research is needed to investigate the relationship between increased contact stresses at the bone-implant interface and TAR failure.

Additive manufacturing (AM) of polymeric materials offers many benefits, from rapid prototyping to the production of end-use material parts. Powder bed fusion (PBF), more specifically selective laser sintering (SLS), is a very promising AM technology. However, up until now, most SLS research has been directed toward polyamide powders. In addition, only basic models have been put forward that are less directed to the identification of the most suited operating conditions in a sustainable production context. In the present combined experimental and theoretical study, the impacts of several SLS processing parameters (e.g., laser power, part bed temperature, and layer thickness) are investigated for a thermoplastic elastomer polyester by means of colorimetric, morphological, physical, and mechanical analysis of the printed parts. It is shown that an optimal SLS processing window exists in which the printed polyester material presents a higher density and better mechanical properties as well as a low yellowing index, specifically upon using a laser power of 17–20 W. It is further highlighted that the current models are not accurate enough at predicting the laser power at which thermal degradation occurs. Updated and more fundamental equations are therefore proposed, and guidelines are formulated to better assess the laser power for degradation and the maximal temperature achieved during sintering. This is performed by employing the reflection and absorbance of the laser light and taking into account the particle size distribution of the powder material.

Uncured solid bisphenol-A epoxy resins containing up to 20 wt% carbon nanotubes (CNTs) were prepared using melt blending in a high shear mixer. The extrudate was ground to produce fine nanocomposite (NC) powders. This simple method produced well-dispersed NC, with CNT agglomerate sizes below 1 μm. Consolidated NCs displayed improved tensile moduli and strengths up to 3.3 GPa (+32%) and 78 MPa (+19%), respectively at 15 wt% CNT, compared to the pure cured epoxy matrix. The relatively high Tg of 39 ◦C for the uncured NC powders simplified the manufacture of composite prepregs using wet powder impregnation. The prepregs were laminated into hierarchical carbon fibre reinforced composites with improved through-thickness properties. Interlaminar shear strength improved for intermediate CNT loadings in the matrix up to 65 MPa (10 wt% CNT, +19%) but decreased at higher concentrations. Compression moduli remained constant irrespectively of CNT loading but compression strength increased with a CNT loading of 2.5 wt% to 772 MPa (+31%). The mechanical properties of the hierarchical composites reflect good consolidation (void content

Magnesium-based alloy WE43 is a state-of-the-art bioresorbable metallic implant material. There is a need for implants with both complex geometries to match the mechanical properties of bone and refined microstructure for controlled resorption. Additive manufacturing (AM) using laser powder bed fusion (LPBF) presents a viable fabrication method for implant applications, as it offers near-net-shape geometrical control, allows for geometry customization based on an individual patient, and fast cooling rates to achieve a refined microstructure. In this study, the laser-alloy interaction is investigated over a range of LPBF-relevant processing conditions to reveal melt-pool dynamics, pore formation, and the microstructure of laser-melted WE43. In situ X-ray imaging reveals distinct laser-induced vapor depression morphology regimes, with minimal pore formation at laser-scan speeds greater than 500 mm/s. Optical and electron microscopy of cross-sectioned laser tracks reveal three distinct microstructural regimes that can be controlled by adjusting laser-scan parameters: columnar, dendritic, and banded microstructures. These regimes are consistent with those predicted by the analytic solidification theory for conduction-mode welding, but not for keyhole-mode tracks. The results provide insight into the fundamental laser-material interactions of the WE43 alloy under AM-processing conditions and are critical for the successful implementation of LPBF-produced WE43 parts in biomedical applications., Crystals, 12 (10), ISSN:2073-4352

Interlayer cold joint formation in roller compacted concrete (RCC) structures is inevitable because of typically applied in layers. In this study, the effect of interlayer cold joint formation on the water absorption and freeze-thaw resistance of RCC with fly ash was investigated. After the first layer of specimens is placed and compacted, the second layer was cast with a delay of 0, 60, 120 and 180 min in order to investigate the cold joint effects. In addition, RCC specimens were produced by applying the mortar between the layers to prevent interlayer cold joint formation. Water absorption and freeze-thaw experiments were performed on RCCs. According to the test results, cold joint formation arising from prolongation of delay increased the water absorption of RCCs and reduced freeze-thaw resistance. However, the application of mortar is an effective method to overcome the interlayer cold joint. Besides, partial substitution of aggregate with fly ash in mixtures improved the workability, impermeability, strength and freeze-thaw resistance of RCC. However, although partial replacement of the cement with fly ash improved the workability and freeze-thaw resistance of some of RCC mixtures, it increased the water absorption and decreased the compressive strength., Scientific and Technological Research Council of Turkey (TUBITAK) [217M408]; Bursa Uluda University Science and Technology Centre (BAP) [AYP (MH)-2016/16], The authors appreciate the contributions of the Scientific and Technological Research Council of Turkey (TUBITAK) and Bursa Uluda University Science and Technology Centre (BAP) under grant numbers 217M408 and AYP (MH)-2016/16, respectively. The authors would also like to thank Polisan Construction Chemicals Company and Bursa-Beton Ready Mixed Concrete authorities for their kind assistance in providing the cement, aggregate and water-reducing admixture as well as determining their properties.

Concrete structures are exposed to water throughout their service life. Nowadays, fiber-reinforced concrete is the most preferred concrete due to its superior mechanical properties. However, good mechanical properties alone cannot protect concrete against the environmental conditions it may encounter during its service life. In particular, water is an inevitable factor faced by concrete elements. In this study, the permeability properties of concrete produced with different combinations of four different fibers were investigated. Hybrid fiber concrete (HFC) was made using the central composite design method. Steel, glass fiber, synthetic, and polypropylene fibers were hybridized among themselves, and the aggregate and paste phases of concrete were hybridized with electric arc furnace slag aggregate (EAFS) and fly ash (FA), respectively. Ultrasonic pulse rate, rapid chloride permeability (RCP), capillary water absorption capacity, and carbonation depth (CD) of HFC were determined. Statistically significant and nonsignificant parameters for each response were determined. Simultaneous substitution of EAFS and FA reduced the capillarity coefficient and CD of HFC. The RCP of HFC depends mainly on two factors: binder dosage and steel fiber ratio. The most suitable fiber for reducing CD was glass fiber. The estimated RCP, ultrasonic pulse velocity (UPV), and capillary water absorption capacity (CWAC) results were compared with the control sample, and the results were 81%, 114%, and 86% of the control sample.

International audience; The relevance of the phase-field approach to simulate the fracture in porous ceramics has been investigated. For this purpose, the conditions for the crack initiation using the phase-field model have been compared to the theoretical predictions of the coupled criterion considering a pure V-notch singularity and a crack blunted by a cavity. For two types of ceramics (3YSZ and 8YSZ), it has been shown that the phase-field approach is able to simulate accurately the crack nucleation as predicted by the coupled stress-energy criterion. The nature of the regularization parameter l for the phase-field model has been discussed as function of the material and the local geometry where the crack initiates. Moreover, the apparent fracture toughness and the compressive fracture strength have been calculated for real porous YSZ ceramics. It has been found that the fracture properties of these complex 3D porous materials can be correctly predicted with the phase-field model. For specimen loaded under compression, it has been shown that the model is able to capture and explain the transition from a brittle behavior towards a diffuse damage when increasing the porosity.

In this study, the effects of CaCO3 and SiO2 nanoparticles on tensile strength of E-Glass fiber composite materials were investigated. Composite structures were produced by mixing CaCO3 nanoparticles into 3%, 5% and 10% by weight, SiO2 nanoparticles into 1%, 3% and 5% by weight epoxy resin. High nanoparticle rates are due to the large diameter of the powders and the desire to form a darker resin. In addition, different fiber orientations were used to emphasize inclusion of nano-additive materials into the resin in case of a decrease in the number of unidirectional fibers. Samples prepared according to the ASTM D3039 Standards were tested by uniaxial tensile machine, Instron 8801. Scanning electron microscopy analysis were performed and failure was mainly caused by debonding and clumping of fibers and fiber/matrix failure. An inclusion of CaCO3 and SiO2 nanoparticles improved the strength of the glass fiber composite sandwich structures. The optimum amount of nano-particles supplemented with different ratios were determined as 3% for CaCO3 and 1% for SiO2. Sufficient enough nanoparticles inclusion increased the quality of the adhesion between fiber and matrices. The inclusion of nanoparticle additives in E-Glass fiber composite materials had a significant effect and positively affected the adhesion properties of the matrix., Bu çalışmada, CaCO3 ve SiO2 nano parçacıkların E-Cam elyaf kompozit malzemelerin çekme dayanımı üzerindeki etkileri araştırılmıştır. Kompozit plakalar, CaCO3 nano parçacıkların ağırlıkça %3, %5 ve%10, SiO2 nano parçacıkların ağırlıkça %1, %3 ve%5 oranında epoksi reçineye karıştırılmasıyla üretilmiştir. Yüksek nano parçacık oranları, tozların geniş çapından ve daha koyu bir reçine oluşturma arzusundan kaynaklanmaktadır. Ek olarak, tek yönlü elyaf sayısında azalma olması durumunda nano katkı maddelerinin reçineye dahil edilmesini vurgulamak için farklı elyaf oryantasyonları kullanılmıştır. ASTM D3039 Standartlarına göre hazırlanan numuneler tek eksenli çekme test cihazı, Instron 8801 ile test edilmiştir. Taramalı elektron mikroskobu analizler yapılarak hasarların liflerin bağlarının ayrılması ve kümelenmesi ve elyaf/matris bozulması olarak gerçekleştiği görülmüştür. CaCO3 ve SiO2 nano parçacıkların dahil edilmesi, cam elyaf kompozit sandviç yapıların dayanımını arttırmıştır. Farklı oranlarda takviye edilmiş optimum nano parçacık miktarı CaCO3 için%3 ve SiO2 için%1 olarak belirlenmiştir. Yeterli nano parçacık ilavesi, fiber ve matrisler arasındaki yapışma kalitesini geliştirmiştir. Nano parçacık katkı maddelerinin E-Cam elyaf kompozit malzemelere dahil edilmesi önemli bir etkiye sahipti ve matrisin yapışma özelliklerini olumlu yönde etkilemiştir.

Articular cartilage tissue engineering offers promising alternative approaches using scaffolds, cells, and growth factors to current treatments to repair cartilage damage. Considering the existing treatment options for damaged cartilage that do not provide a permanent solution, it is important to mimic the extracellular matrix in the scaffolds to be developed and to provide an ideal microenvironment for chondrocytes. The scaffolds to be used for this purpose should be biocompatible, non-toxic, highly porous, and biodegradable and possess the desired mechanical properties. Microbial biopolymers have shown promising results in cartilage tissue engineering. These biopolymers can be classified as polysaccharides (bacterial cellulose, hyaluronic acid, alginate, dextran, pullulan, gellan gum, and xanthan gum), polyesters (polyhydroxyalkanoates), and polyamides (poly-gamma-glutamic acid and epsilon-poly-L-lysine). Although the functions of biopolymers as tissue scaffolds differ according to their properties, they are often used as a main support material; and their adjustable functionality by various modifications increases their pertinence. This review focuses on the use, modifications, and functionalization of microbial biopolymers in targeted scaffold designs for cartilage repair in articular cartilage tissue engineering., Scientific Research Foundation of Ege University [FOA-2020-21947], This work was partially supported by The Scientific Research Foundation of Ege University (Grant number FOA-2020-21947).

Recent development in the field of additive manufacturing, also known as three-dimensional (3D) printing, has allowed for the incorporation of continuous fiber reinforcement into 3D-printed polymer parts. These fiber reinforcements allow for the improvement of the mechanical properties, but compared to traditionally produced composite materials, the fiber volume fraction often remains low. This study aims to evaluate the in-nozzle impregnation of continuous aramid fiber reinforcement with glycol-modified polyethylene terephthalate (PETG) using a modified, low-cost, tabletop 3D printer. We analyze how dimensional printing parameters such as layer height and line width affect the fiber volume fraction and fiber dispersion in printed composites. By varying these parameters, unidirectional specimens are printed that have an inner structure going from an array-like to a continuous layered-like structure with fiber loading between 20 and 45 vol%. The inner structure was analyzed by optical microscopy and Computed Tomography (µCT), achieving new insights into the structural composition of printed composites. The printed composites show good fiber alignment and the tensile modulus in the fiber direction increased from 2.2 GPa (non-reinforced) to 33 GPa (45 vol%), while the flexural modulus in the fiber direction increased from 1.6 GPa (non-reinforced) to 27 GPa (45 vol%). The continuous 3D reinforced specimens have quality and properties in the range of traditional composite materials produced by hand lay-up techniques, far exceeding the performance of typical bulk 3D-printed polymers. Hence, this technique has potential for the low-cost additive manufacturing of small, intricate parts with substantial mechanical performance, or parts of which only a small number is needed.

This review paper provides a recent overview of current international research that is being conducted into the functional properties of cellulose as a nanomaterial. A particular emphasis is placed on fundamental and applied research that is being undertaken to generate applications, which are now becoming a real prospect given the developments in the field over the last 20 years. A short introduction covers the context of the work, and definitions of the different forms of cellulose nanomaterials (CNMs) that are most widely studied. We also address the terminology used for CNMs, suggesting a standard way to classify these materials. The reviews are separated out into theme areas, namely healthcare, water purification, biocomposites, and energy. Each section contains a short review of the field within the theme and summarizes recent work being undertaken by the groups represented. Topics that are covered include cellulose nanocrystals for directed growth of tissues, bacterial cellulose in healthcare, nanocellulose for drug delivery, nanocellulose for water purification, nanocellulose for thermoplastic composites, nanocellulose for structurally colored materials, transparent wood biocomposites, supercapacitors and batteries.

The present study explores the possibility of replacing blast furnace slag (BFS) with coal fly ash (FA) to produce alkali-activated material (AAM) concrete with hybrid precursors. With an increased FA replacement ratio, the reaction kinetics, fresh and hardened properties of AAM mixtures have been investigated. The retardation effect on the reaction kinetics with an increased FA content has been observed, which not only extended the induction period along with the heat flow evolution but also reduced the cumulative heat release up to 24 h. Spherical FA particles can provide a ball-bearing effect to improve the workability of the hybrid AAM mixtures, while FA also slows down the deterioration of fresh properties since they are less reactive compared to BFS particles. Regarding the strength development, FA results in the reduction at all curing ages in the mixtures with a low silicate modulus (Ms0.25). Similarly, reduction in 1-day compressive strength has been detected in high silicate modulus mixtures (Ms0.5) with FA replacement, while the mixture with 10% FA exhibits the highest compressive strength among Ms0.5 concretes at later curing ages. Bigger capillary pores have been detected in AAM mixtures with an increase in FA content. However, AAM with 10% FA shows the lowest porosity in Ms0.5 mixtures, which is in agreement with the compressive strength results.

This study aims to design an alternative way for the laminated fabric manufacturing with a cleaner production method, by using a bio-based coating formulation and time/cost saving, environmentally friendly UV-curing technology, compared to the conventional petroleum based, heat and solvent requiring laminating process. For this purpose, acrylated epoxidized soybean oil oligomer was synthesized and included in coating formulations for the application on cotton fabrics via UV-curing. The obtained oligomer was characterized by FTIR and NMR spectroscopies. In order to enhance the bonding between the fabric and coating layer, fabrics were pretreated by sodium hydroxide, pectinase enzyme, and a commercial washing agent prior to the coating process. The effects of pretreatment methods on the wettability, tensile and peel strength, and abrasion resistance of the fabrics were all examined before/after coating process. Enzyme pretreatment revealed promising results by increasing the surface roughness, fibrillation, and hydrophilicity of the cotton fabrics. After coating and UV-curing process, the highest increment in tensile strength, the highest peel strength, and the least weight loss value against abrasion were all recorded in enzyme pretreated fabric.

This study aimed to develop promising and innovative mucoadhesive gel systems containing dexamethasone-loaded nanoparticle to increase the effectiveness of treatment for oral precancerous lesions and to reduce side effects. In this respect, a dexamethasone-loaded nanoparticle formulation was prepared by using emulsification/solvent evaporation method. The nanoparticle has high zeta potential (-10.3??0.5 mV), low particle size (218.42??2.1), low polydispersity index (0.070??0.014) and high encapsulation efficiency (95.018??2.982%). To improve the mucosal retention time, the dexamethasone-loaded nanoparticle was dispersed in mucoadhesive gel using gellan gum. The developed gels offered appropriate pH value, high drug content, suitable mechanical and mucoadhesive performance and appropriate viscosity for mucosal administration. All formulations exhibited plastic flow and typical gel-type mechanical spectra after the determined frequency value. The developed formulations exhibited extended drug release as intended for these systems. Cytotoxicity was tested by MTT assay in human epithelioid carcinoma cell (HeLa) in vitro. The MTT assay showed that the blank formulations were non-toxic to cells. It was observed that the bioactivity of the free dexamethasone was potentiated by mucoadhesive gels containing dexamethasone-loaded nanoparticle in HeLa cells. Results from this study indicate that mucoadhesive gels are effective for the local treatment of precancerous lesions. Our findings showed that the developed formulations were worthy of further studies., Ege University [16/ECZ/015], This study was supported by a research grant from Ege University (16/ECZ/015) . We would like to that E.U. Pharmaceutical Sciences Research Center for enabling us to use their laboratory instruments.

Advanced expertise and technologies have been devoted to producing high functional materials with a polycrystalline nature, which is transparent to visible light for various manufacturing applications. Materials with a good lattice structure can also be adopted in the manufacturing of transparent ceramics. Observations from the literature showed that oxide-based transparent ceramics had been successfully utilized, owing to their remark-able mechanical properties, chemical stability, and a wide range of flexible synthesis routes. Translucent zirconia (ZrO2) ceramics have drawn enormous attention from re-searchers in different fields due to their outstanding properties such as oxygen (O2) con-ductivity, mechanical behavior, functional properties, high level of toughness, and thermal conductivity. The Cubic and tetragonal crystal structure of zirconia can be applied for stabilizing Yttria (Y2O3) to enhance its optical performance and mechanical strength. Due to high chemical stability and high refractive index within the range of 2.2, transparent yttria-stabilized zirconia ceramic has been found useable in varying applications, including electromagnetic radiation, and camera lenses. The purity of starting materials and sin-tering techniques has been considered the proper production process for obtaining fully dense ceramics with less than 0.01% residual porosity for optical transparency. Scientists compared both conventional and modern processing techniques for transparent ceramic materials, the findings shows that modern processing techniques were better in morphological/mechanical properties. Consequently, the major drawbacks experienced during the consolidation processes can be attributed to the chemical impurity of sintering methods, the ceramic or the processing flexibility of the ceramic, sintering aids employed, and microstructural characteristics (e.g., porosity). In this review, an effort was made to summarize the advancement of transparent YSZ ceramics, focusing on applications and various consolidation technologies. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Numerous industrial applications, particularly those in the transport industry, require the joining of dissimilar materials which offers considerable benefits in terms of low cost, design flexibility, and weight reduction for overall structures. The problems associated with conventional fusion welding processes have stimulated researchers in recent years to develop new joining methods for dissimilar materials which are particularly difficult to join. Friction stir welding (FSW) originally developed for joining difficult-to-weld Al-alloys and FSSW (a variant of FSW for spot welding) have exhibited great potential for obtaining sound joints in various dissimilar alloy systems in different configurations namely butt-, lap- and spot-welding, particularly in dissimilar Al-alloys systems with different properties, which are very difficult to weld using conventional fusion welding techniques. A major difficulty in joining dissimilar Al-alloys by FSW/FSSW lies in the discontinuity in mechanical and technological properties (such as high-temperature strength, plastic deformation capacity, viscosity, etc.) of the materials to be welded across the abutting surfaces. This discontinuity as well as inherent asymmetry in heat generation and material flow of FWS/FSSW processes causes a higher asymmetry in materials flow behavior in dissimilar welding. However, it is relatively easier to implement the FSW/FSSW process to dissimilar Al-alloys in contrast to FSW of dissimilar materials combinations with very differing properties, such as Al-alloy to Mg-alloy or Al-alloy to steel.

In contrast to subtractive manufacturing processes, such as machining, and forming processes, additive manufacturing (AM), which is also called 3-D printing, direct digital manufacturing or free form fabrication, is a process of joining materials to make objects from 3D model data, usually layer by layer. Although additive manufacturing was mainly used in the production of prototypes from polymeric materials initially, the production of metallic parts with this manufacturing technology has attracted great interest in recent years. This innovative technology is commonly referred to metal additive manufacturing (MAM) and is presently being applied in various industries such as aeronautics-space, energy, automotive, medicine, various tools and customer goods. Metal parts are produced in three different ways by MAM methods. These are powder bed fusion, powder feed fusion and wire feed fusion systems. In the first two of these additive manufacturing methods, metal or alloy powders are used as raw materials, while in the third method, the filler wire made of metals or alloys is the starting material. However, metal powders, especially alloy powders, are quite costly. This in turn makes the production of metal parts using filler wire very attractive. Another advantage of wire feed additive manufacturing systems, particularly of wire arc additive manufacturing (WAAM), is its potential to produce small- and medium-sized metallic parts economically with high deposition rate. Nowadays, this innovative manufacturing technology is being considered as a promising fabrication technology for manufacturing several products from various engineering materials including aluminum and its alloys. In this paper, studies on WAAM of Al-alloy parts will be discussed. In addition, the most common defect (i.e., porosity) encountered in Al-alloy parts produced by WAAM will be considered as well as the precautions taken against its formation.

The present study experimentally investigates the effect of various ceramic particles and different particle weight fractions on the bearing strength and failure modes of pinned joints in woven glass/epoxy composite plates. The composite plates are filled with Silicon Carbide (SiC), Aluminum Oxide (Al2O3) and Boron Carbide (B4C) ceramic particles at 5%, 10% and 15% weight fractions. Tensile tests were carried out on single pinned joints in woven glass/epoxy composite specimens. Accordingly, the effects of ceramic particles, particle weight fractions and pin joint geometry were evaluated on the bearing strength and the failure modes. The damaged specimens were examined with load–pin displacement curves, visual and scanning electron microscope (SEM). The results showed that the bearing strength and failure mode were considerably affected by the ceramic particles, the particle weight fractions and the geometric dimensions. It was found that the addition of the ceramic particles into composites improved the bearing strengths of pinned joints in the composites for all weight fractions compared to the unfilled composite. The highest bearing strengths were obtained for composites filled with 10 wt.% particles. As a result, the increase in the bearing strength is almost 43% for composites filled with SiC, 53% filled with Al2O3 and 47% filled with B4C compared to the unfilled composite, for ratio e/d = 3.

Waste polymers have been employed as a modifier in bitumen to improve the performance of the binders and reduce plastic pollution. Grafting of maleic anhydride (MA) is a method to increase the chemical and physical consistency between the polymer and binder. In this study, maleic anhydride grafted waste polypropylene was employed as a bitumen modifier. Gamma irradiation is applied to waste polypropylene to improve the compatibility. The effects of MA-grafted irradiated waste polypropylene (PPR-gamma-MA) on physical and rheological properties of bitumen were investigated through a test program. Storage stability tests signifies that the gamma irradiation could diminish the phase separation between the modifier and bitumen. The thermorheological tests showed employing PPR-gamma-MA improves the high temperature performance, whilst it has a slightly adverse effect on low temperature performance of bitumen. The results of multiple stress creep recovery (MSCR) test indicate that PPR-gamma-MA reduces the non-recoverable deformation and enhanced elastic recovery of the material, whereas the linear amplitude sweep (LAS) test result signifies PPR-gamma-MA improved the fatigue life of asphalt by increasing fatigue damage resistance under different strain levels. The rheological test results emphasised on the usability of PPR-gamma-MA as a modifier in binders., Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, This work was supported by Turkiye Bilimsel ve Teknolojik Arastirma Kurumu.

Because the experimental trials in civil engineering field are difficult and time-consuming, the application of artificial intelligence (AI) techniques is attracting considerable attention, with their use enabling successful results to be more easily obtained. In this study, we investigated the effect of fiber size, fiber amount, water content, and cell pressure on maximum deviator stress (MDS) and failure deformation (FD) of basalt fiber (BF) -reinforced, unsaturated silty soils using three AI techniques: the artificial neural network (ANN), support vector machine (SVM), and fuzzy logic (FL). The numerical analyses and experiments were conducted using varying amounts (1, 1.5, and 2%) and lengths (6, 12, and 24 mm) of BF, and a total of 180 samples were prepared for the detailed investigation. In order to compare model performances, R-2 and MAPE goodness-of-fit metrics were used. The experimental results revealed that the addition of BF generally increased the MDS of the soils, which corresponds to the shearing resistance. According to AI models result, FL outperformed the SVM and ANN, with a R-2 value of 0.938, especially in FD prediction. The sensitivity analysis was performed to ascertain the effect of the inputs on the MDS and FD response variables. Results revealed that fiber length and cell pressure have substantial influence in MDS estimations., Polish National Agency for Academic Exchange [PPI/APM/2019/1/00003], Declarations The scientific collaborations of this article have been improved by the support of the Polish National Agency for Academic Exchange under Grant No. PPI/APM/2019/1/00003. Besides, the authors would like to express their gratitude to Sakarya University geotechnical engineering laboratory for their contributions to the experimental studies. Please find our paper titled ?Investigation of the effect of basalt fiber size on maximum deviator stress (MDS) and failure defor-mation (FD) of silty soils: A predictive study using AI techniques?. We are submitting for possible publication in Advances in Engineering Software.

In this work, multipass torsion tests followed by coiling simulations under different conditions have been performed with a reference Nb (0.03 pct) and a high Ti (0.1 pct)–Nb-microalloyed (0.03 pct) steel. In the case of the high Ti steel, estimated yield strengths close to or over 700 MPa were obtained for some of the conditions researched. However, a very significant effect of previous austenite grain size and strain accumulation on precipitation strengthening has also been observed. As a result, depending on deformation sequence and final cooling conditions, the coiling simulation temperatures that lead to the highest mechanical strength varied from 600 °C to 500 °C. The effect of increasing strain accumulation was mainly related to higher phase transformation temperatures, which led to a lower driving force for precipitation and higher microalloying element diffusivity, resulting in the formation of less and coarser precipitates.

Objective: New generation High Viscosity Glass Ionomer Cements (HVGICs) have enhanced physical and mechanical properties. By effectively closing the restoration margin, it ensures that the restorations will last longer. The aim of this study was to investigate the clinical performances of heat-cured versus non heated HVGIC in class II restorations of deciduous molars. Methods: This randomized, split mouth, multicentre study was performed in four different centres. A total of 250 deciduous molars from 88 individuals were randomly allocated to one of the following groups: 1) non-heated (n = 125) 2) heated (n = 125) and restored with a HVGIC using LED light for heat application. Restorations were clinically evaluated according to the modified USPHS at the baseline, 6 months and 12 months. The survival analysis was performed by Kaplan Meier and Life Tables. This study was retrospectively registered to the ClinicalTrials.gov with the ID number of NCT04291872 at 2nd March 2020. Results: No statistically significant differences were found between the groups regarding to modified USPHS criteria (p>0.05). Success rate in retention criteria was 94.1% of the heat-cured and 92.6% of the non-heated restorations after 12 months. The mean survival time was 11.8 ±0.1 months in the heated group, while 11.9±0.1 months in the non-heated group. Conclusion: The heat treated HVGIC for Class II restorations did not show any significant differences in 12 months’ follow-up compared with the conventional technique.

Marine-based biomolecules are emerging metabolites that have gained attention for developing novel biomaterials, drugs, and pharmaceutical in vitro platforms. Here, we developed a 3D engineered neural co-culture model via a 3D prototyped sliding frame-platform for multi-step UV lithography and investigated the neurovascular potential of citreohybridonol in neuroblastoma treatment. Citreohybridonol was isolated from a sponge-derived fungus Penicillium atrovenetum. The model was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy analysis. Human umbilical cord vein endothelial cells (HUVECs) and neuroblastoma (SH-SY5Y) cell lines were encapsulated in gelatin methacrylate (GelMA) with and without citreohybridonol. The effect of citreohybridonol on the proliferation capacity of cells was assessed via cell viability and immunostaining assays. GelMA and 3D culture characterization indicated that the cells were successfully encapsulated as axenic and mixed with/without citreohybridonol. The cytotoxic test confirmed that the 3D microenvironment was non-toxic for cultural experiments, and it showed the inhibitory effects of citreohybridonol on SH-SY5Y cells and induced the proliferation of HUVECs. Finally, immunohistochemical staining demonstrated that citreohybridonol suppressed SH-SY5Y cells and induced vascularization of HUVECs in mixed 3D cell culture., Tubitak 2232 International Fellowship for Outstanding Researchers Award [118C391]; Alexander von Humboldt Research Fellowship for Experienced Researchers; Marie Sklodowska-Curie Individual Fellowship [101003361]; Science Academy's Young Scientist Awards Program (BAGEP); Bilim Kahramanlari Dernegi Young Scientist Award; Royal Academy NewtonKatip Celebi Transforming Systems Through Partnership Award [120N019]; Outstanding Young Scientists Awards (GEB.IP), S.T. acknowledges the Tubitak 2232 International Fellowship for Outstanding Researchers Award (Grant No. 118C391), the Alexander von Humboldt Research Fellowship for Experienced Researchers, the Marie Sklodowska-Curie Individual Fellowship (Grant No. 101003361), and the Royal Academy NewtonKatip Celebi Transforming Systems Through Partnership Award (Grant No. 120N019) for financial support of this research. This work was partially supported by the Science Academy's Young Scientist Awards Program (BAGEP), the Outstanding Young Scientists Awards (GEB.IP), and the Bilim Kahramanlari Dernegi Young Scientist Award. Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the TUB.ITAK.

Background: Hydrogels based on organic/inorganic composites have been at the center of attention for the fabrication of engineered bone constructs. The establishment of a straightforward 3D microenvironment is critical to maintaining cell-to-cell interaction and cellular function, leading to appropriate regeneration. Ionic cross-linkers, Ca2+, Ba2+, and Sr2+, were used for the fabrication of Alginate-Nanohydroxyapatite-Collagen (Alg-nHA-Col) microspheres, and osteogenic properties of human osteoblasts were examined in in vitro and in vivo conditions after 21 days. Results: Physicochemical properties of hydrogels illustrated that microspheres cross-linked with Sr2+ had reduced swelling, enhanced stability, and mechanical strength, as compared to the other groups. Human MG-63 osteoblasts inside Sr2+ cross-linked microspheres exhibited enhanced viability and osteogenic capacity indicated by mineralization and the increase of relevant proteins related to bone formation. PCR (Polymerase Chain Reaction) array analysis of the Wnt (Wingless-related integration site) signaling pathway revealed that Sr2+ cross-linked microspheres appropriately induced various signaling transduction pathways in human osteoblasts leading to osteogenic activity and dynamic growth. Transplantation of Sr2+ cross-linked microspheres with rat osteoblasts into cranium with critical size defect in the rat model accelerated bone formation analyzed with micro-CT and histological examination. Conclusion: Sr2+ cross-linked Alg-nHA-Col hydrogel can promote functionality and dynamic growth of osteoblasts., Sahand University of Technology, This study was supported by a grant from Sahand University of Technology.

It is important to know the physical and mechanical properties of natural building stones, which have limited and at the same time decreasing reserves in nature, according to their usage areas. The two most important of these properties are abrasion and strength. Determining the strength parameters in terms of frost resistance is also required in terms of selecting the proper usage area of the stone. This study was carried out to reveal the physical and mechanical behavior of low porosity (< 1%) carbonate rocks under the effect of freezing and thawing (FT) and to examine the variations of physical and mechanical parameters. In this context, 4, 7, 10, 14, 20, 28, 35, 56, 70 and 84 FT cycles were carried out on 8 different carbonate rocks taken from different regions of Turkey. After the FT cycles, the data on the physical and mechanical properties of the samples were evaluated. The variation of physical and mechanical values with the number of FT cycles was preŞented graphically by considering the average values of all samples, and statistical evaluations were examined. In addition, the changes in the physical and mechanical properties of the rocks after FT cycles were evaluated in accordance with ASTM standards and some classifications commonly used in the literature.

Iron-based superalloys are alloys produced for use in corrosive environments as an alternative to high-cost nickel-based superalloys. However, their average strength and hardness, attributed to their austenitic structures, limit their use in tribological applications. In an attempt to counter these drawbacks, boriding was applied to an iron-based A286 superalloy having an initial surface hardness of 320 HV. Boriding kinetics, some mechanical properties, and tribo-wear (ambient air and 3.5 NaCl environment) behaviors of the formed boride layers were investigated. Multicomponent boride layers (consist of FeB, Fe2B, CrB, NiB, Ni4B3) were formed on the surface of the alloy, with hardness and thickness values of 1498-1961 HV and 20-130 mu m, respectively, depending on the boriding temperature and the treatment time. The integral diffusion model was adopted to deal with the kinetics of monoboride and hemiboride layers formed on the surface. The boron activation energies of FeB, Fe2B, and DZ layer were estimated as equal to 175.86, 198.7, and 205.73 kJ mol- 1, respectively. As a result of increased surface hardness, all of the borided samples displayed reduced friction coefficients and higher wear resistance compared to the untreated alloy, in both ambient air and 3.5% NaCl. However, the increase in wear resistance was not proportional to the increase in hardness; while the best wear resistance was obtained in samples borided at 850-950 degrees C for 6 h, the lowest wear resistance was obtained in samples borided for 4-6 h at 1050 degrees C. This situation was caused by the Kirkendall effect and residual stresses in the structure of alloying elements with different diffusion rates due to the high-temperature effect of the boriding process.

The application of 3D printing technologies fields for biological tissues, organs, and cells in the context of medical and biotechnology applications requires a significant amount of innovation in a narrow printability range. 3D bioprinting is one such way of addressing critical design challenges in tissue engineering. In a more general sense, 3D printing has become essential in customized implant designing, faithful reproduction of microenvironmental niches, sustainable development of implants, in the capacity to address issues of effective cellular integration, and long-term stability of the cellular constructs in tissue engineering. This review covers various aspects of 3D bioprinting, describes the current state-of-the-art solutions for all aforementioned critical issues, and includes various illustrative representations of technologies supporting the development of phases of 3D bioprinting. It also demonstrates several bio-inks and their properties crucial for being used for 3D printing applications. The review focus on bringing together different examples and current trends in tissue engineering applications, including bone, cartilage, muscles, neuron, skin, esophagus, trachea, tympanic membrane, cornea, blood vessel, immune system, and tumor models utilizing 3D printing technology and to provide an outlook of the future potentials and barriers.

The demand for joining dissimilar metals has exponentially increased due to the global concerns about climate change, especially for electric vehicles in the automotive industry. Ultrasonic welding (USW) surges as a very promising technique to join dissimilar metals, providing strength and electric conductivity, in addition to avoid metallurgical defects, such as the formation of intermetallic compounds, brittle phases and porosities. However, USW is a very sensitive process, which depends on many parameters. This work evaluates the impact of the process parameters on the quality of ultrasonic spot welds between copper and aluminium plates. The weld quality is assessed based on the tensile strength of the joints and metallographic examination of the weld cross-sections. Furthermore, the welding energy is examined for the different welding conditions. This is done to evaluate the influence of each parameter on the heat input resulting from friction at the weld interface and on the weld quality. From the obtained results, it was possible to optimise parameters to achieve satisfactory weld quality in 1.0 mm thick Al–Cu plate joints in terms of mechanical and metallurgical properties.

Previous studies have yet to show a consistent effect of severe plastic deformation (SPD) processing on the wear behavior of different metals and alloys. To fill this scientific gap, this study investigated the effect of the cyclic extrusion compression (CEC) process, as one of the prominent SPD techniques, on the wear behavior of AA5052. In addition, the microstructure evolution and mechanical properties of the sample before and after the process were experimentally examined and studied. It was found that the yield and ultimate tensile strength of the AA5052 improved significantly after the first pass, while the elongation-to-failure decreased considerably. Further, the subsequent passes mildly changed the trend of increasing strength and reducing elongation-to-failure. SEM morphology indicated that the ductile mode of the initial annealed alloy changed to a combination of ductile and brittle failure modes, in which the level of the brittle failure mode increased with the addition of passes. TEM observations showed that the grain refinement during the CEC process included the formation of dislocation cell structures, subgrain boundaries, and low-angle grain boundaries, with the subgrain boundaries initially evolving into low-angle grain boundaries and, eventually, due to the imposition of additional plastic strain, into high-angle grain boundaries. Furthermore, the CEC process and its increased number of passes led to a significant improvement in wear resistance due to the enhanced tensile strength achieved through grain refinement. In this regard, the wear mechanism of the initial alloy was a combination of adhesion and delamination, with the plastic deformation bands changing to plowing bands with decreased adhesive wear during the process. Eventually, oxidization was found to be a mechanism contributing to wear under all conditions.

The evolution of biosensors and diagnostic devices has been thriving in its ability to provide reliable tools with simplified operation steps. These evolutions have paved the way for further advances in sensing materials, strategies, and device structures. Polymeric composite materials can be formed into nanostructures and networks of different types, including hydrogels, vesicles, dendrimers, molecularly imprinted polymers (MIP), etc. Due to their biocompatibility, flexibility, and low prices, they are promising tools for future lab-on-chip devices as both manufacturing materials and immobilization surfaces. Polymers can also allow the construction of scaffold materials and 3D structures that further elevate the sensing capabilities of traditional 2D biosensors. This review discusses the latest developments in nano-scaled materials and synthesis techniques for polymer structures and their integration into sensing applications by highlighting their various structural advantages in producing highly sensitive tools that rival bench-top instruments. The developments in material design open a new door for decentralized medicine and public protection that allows effective onsite and point-of-care diagnostics.

Naturally sourced materials have an important place in bone tissue engineering due to their biocompatibility and biodegradability. Non-diatom, diatom-doped chitosan/hydroxyapatite (CS/HAp) and collagen/chitosan/hydroxyapatite (Col/CS/HAp) as three-dimensional tissue scaffolds were produced by freeze drying technique. It was determined by SEM analysis that CS/HAp, CS/HAp/Di, Col/CS/ HAp, Col/CS/HAp/Di scaffolds have 160 mu m, 130 mu m, 390 mu m and 340 mu m pores, respectively. The diatoms in the structure have approximately 9-16 mu m in length, 8-20 mu m in diameter and nanopore sizes of 260-330 nm. Cell culture studies were performed using the 3T3 cell line to study the non-toxic nature of biocomposite scaffolds that support cell attachment and proliferation. The cells in the scaffolds without diatom proliferate in a reticulated manner, whereas in the scaffolds containing diatom the cells were wrapped around the scaffold like a cover. The suggested scaffolds have the potential to meet the basic requirements in biocompatibility, cytocompatibility and interconnected pore structure.

Producción Científica, The incorporation of silica aerogel particles into the isocyanate used to prepare Rigid Polyurethane composite foams drastically modifies its rheological behaviour. The isocyanate changes from being a Newtonian fluid of constant viscosity (0.3 Pa s at 25 °C) to a non-linear power-law material with complex viscosity decreasing from 104 to 101 Pa s with a slope −1 versus frequency. The change in response is caused by the formation of a percolated network of particles at contents above 2.5 wt% of aerogel. Moreover, the addition of aerogel significantly slows down the modulus-build up kinetics and vitrification of the matrix by approximately 4.5 min with every 1 wt% of aerogel added. For the foam with 3.0 wt% of aerogel, the combination of high viscosity at early reaction times coupled with the slow modulus build-up impedes the drainage which leads to a decrease in the fraction of material in the struts of the matrix., Junta de Castilla y Leon (project VA202P20), Ministerio de Ciencia, Innovación y Universidades (projects RTI2018-098749-B-I00 and RTI2018 - 097367-A-I00)

Colemanite-polypropylene polymeric material has been fabricated by doping Colemanite material with different ratios 5, 15, 25, and 35 wt% on the polypropylene polymeric material. The produced samples were coded as PC1, PC2, PC3, and PC4, respectively. The phenomenon ionizing radiation shielding capacity of the fabricated material has been examined. The fabricated polymers' density measurement showed that the density increased between 1.06 and 1.59 g/cm(3). The Monte Carlo simulation was used to evaluate effective shielding parameters. The linear attenuation coefficient of the prepared materials increased with the increase in Colemanite content wt%. Opposite to the linear attenuation coefficient, the half-value layer (HVL) is found to follow the order (PC1)(HVL) < (PC2)(HVL) < (PC3)(HVL) < (PC4)(HVL). The radiation protection efficiency (RPE) for all fabricated polymers varied around 100% at gamma-ray photons with an energy of 15 keV. These values were reduced by raising the photon energy to 9.209%, 10.465%, 12.220%, and 13.893% for PC1, PC2, PC3, and PC4, respectively. The RPE shows an increase with the rise in fabricated polymer thickness and the Colemanite ratio in the fabricated polymer. Increasing the colemanite concentration in the fabricated polymer samples causes an observable decrease in both the exposure and energy absorption buildup factors., Taif University, Taif, Saudi Arabia [TURSP-2020/109], This work was supported by Taif University Researchers Supporting Project Number (TURSP-2020/109), Taif University, Taif, Saudi Arabia.

In this study, Ni-based Inconel 718 coatings were additively manufactured on the surface of AISI H13 work tool steel by electro-spark deposition (ESD). Some of the electro-spark deposited samples were boronized at 1000 ? for 5 h to evaluate the effects of boronizing on microstructure, high-temperature wear, and corrosion resistance. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), 2D pro-filometry, wear and electrochemical corrosion testing was used to characterize the surfaces, microstructures, microhardness, some mechanical properties, high-temperature wear, and corrosion resistance of the applied coatings. Wear tests were performed at room temperature and 650 ?, and corrosion tests were performed in 3.5% NaCl at room temperature, considering the applications of AISI H13 and Inconel 718 alloys. The characterization studies showed evidence of microcracking and oxidation in the as-deposited Inconel 178 coatings. In the boronized Inconel 718 coatings, the oxides and microcracks were slightly reduced. The hardness of the boronized Inconel 718 coating was increased to about four times the hardness of the as-deposited Inconel 718 coating, and this significantly improved its wear resistance. The highest wear resistance was achieved with the boronized coating, while the best corrosion resistance was obtained with the as-deposited coating. The improvements in wear resistance provided by boronizing have the potential for expanding the applications of Inconel 718 coatings in machine components.

The demand for dissimilar joining of steel grades, namely austenitic stainless steels to low-alloy steels, may increase in near future owing to the fact that the storing of LNG is currently becoming a necessity, particularly in Europe, due to the shortage of supply or interruptions in the supply. Therefore, successful dissimilar joining of steel grades using traditional fusion welding techniques in such applications is required. In this study, butt-welded joints of AISI 316L austenitic steel and low-alloy steel plates (containing 9% Ni) of 10 mm thickness were fabricated by gas tungsten arc welding employing a Ni-based filler wire. The microstructure and mechanical properties of the weldment were examined by detailed optical microscopy, extensive micro-hardness measurements, and tensile tests. Further, fracture toughness of the joint at cryogenic temperatures (- 196 degrees C) was also determined by Charpy impact test. The dissimilar joint exhibited a high tensile strength of 633 MPa, which is higher than that of the lower-strength AISI 316L base plate (about 600 MPa), while its elongation (21%) was much lower due to confined plasticity. The lowest impact energy was displayed by HAZ-F notched specimens, namely about 62.6 J (0.83 J/mm(2)). However, it is still reasonably above the minimum impact energy specified for the LNG storage tanks, i.e., 0.75 J/mm(2).

In the context of the preservation of natural resources, researchers show a growing interest in developing eco—friendly materials based on recycled polymers and natural fiber biocomposites to minimize plastic and agroindustrial waste pollution. The development of new materials must be integrated within the circular economy concepts to guarantee sustainable production. In parallel, fused deposition modeling, an additive manufacturing technology, provides the opportunity to use these new materials in an efficient and sustainable manner. This review presents the context of plastics and agro-industrial fiber pollution, followed by the opportunity to give them added value by applying circular economy concepts and implementing these residues to develop new materials for the manufacture of fused deposition modeling 3D printing technique feedstock. Colombian perspective is highlighted since 3D printing technology is growing there, and Colombian biodiversity represents a high reservoir of materials. Also, recycling in Colombia promotes compliance with the 2030 Agenda and the Sustainable Development Goals.

International audience; CROUZIER, M., K. TUCKER, L. LACOURPAILLE, V. DOGUET, G. FAYET, M. DAUTY, and F. HUG. Force-sharing within the Triceps Surae: An Achilles Heel in Achilles Tendinopathy. Med. Sci. Sports Exerc., Vol. 52, No. 5, pp. 1076–1087, 2020. Purpose: The primary aim of this study was to determine whether the distribution of force between the three heads of the triceps surae differs between people with Achilles tendinopathy and controls. We also aimed to determine the effect of this force distribution on subtendon strain. Methods: Data were collected for 21 participants with Achilles tendinopathy and 21, case-wise paired, asymptomatic controls. Ultrasonography was used to measure muscle volume, fascicle length, pennation angle and subtendon length at rest. Muscle activation was estimated using surface electromyography during maximal and submaximal isometric plantarflexion tasks. The product of normalized activation, physiological cross-sectional area, and the cosine of the pennation angle was considered as an index of individual muscle force. Displacement of the distalmyotendinous junction of each muscle was measured during the submaximal contractions. Results: The contribution of the gastrocnemius lateralis to the overall triceps surae physiological cross-sectional area and activation was 8.5% (P = 0.047, d = 0.75) and 24.7% lower (main effect group P = 0.009, d = 0.67) in people with Achilles tendinopathy than in the controls, respectively. Consequently, gastrocnemius lateralis contributed approximately 28% less (main effect group P = 0.025, d = 0.62) of the triceps surae force in people with Achilles tendinopathy. The contribution of gastrocnemius medialis and soleus was not different between groups. Subtendon strain was not different between groups (P = 0.835). Conclusions: These results provide evidence for a difference in force-sharing strategy within the triceps surae in people with Achilles tendinopathy compared with the controls. Whether this altered strategy is a cause or a consequence of Achilles tendinopathy should be explored further.

Kaya, Ertugrul/0000-0003-1579-6411; Gerengi, Husnu/0000-0002-9663-4264 WOS: 000497136100001 Dual phase (DP) steels have a great deal of importance in the automotive industry. These steels are used to fabricate structural parts of vehicles with the goal of passenger safety. In this study, the corrosion properties of DP 600 and 800 steel in 3.5wt.% NaCl environment were evaluated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and weight loss methods. Although the samples were quite similar to each other in their composition, it was observed that the very small differences changed the corrosion resistance property. For this reason, the calculated charge transfer resistance (R-ct) of the DP-800 in the 3.5wt.% NaCl environment was 51% greater than that of the DP-600 sample. This finding was confirmed by using weight loss, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and optical profilometer (OP) analysis. Duzce University Research FundDuzce University [2016.06.05.457] For this work, the authors gratefully acknowledge the financial support provided by the Duzce University Research Fund [Project No: 2016.06.05.457].

Using a 3D rotational shear wave elasticity imaging (SWEI) setup, 3D shear wave data were acquired in the vastus lateralis of a healthy volunteer. The innate tilt between the transducer face and the muscle fibers results in the excitation of multiple shear wave modes, allowing for more complete characterization of muscle as an elastic, incompressible, transversely isotropic (ITI) material. The ability to measure both the shear vertical (SV) and shear horizontal (SH) wave speed allows for measurement of three independent parameters needed for full ITI material characterization: the longitudinal shear modulus μ(L), the transverse shear modulus μ(T), and the tensile anisotropy χ(E). Herein we develop and validate methodology to estimate these parameters and measure them in vivo, with μ(L) = 5.77 ± 1.00 kPa, μ(T) = 1.93 ± 0.41 kPa (giving shear anisotropy χ(μ) = 2.11 ± 0.92), and χ(E) = 4.67 ± 1.40 in a relaxed vastus lateralis muscle. We also demonstrate that 3D SWEI can be used to more accurately characterize muscle mechanical properties as compared to 2D SWEI.

A steel with nominal composition Fe-28Mn-8Al-1.0C in mass percent was hot rolled at two temperatures, 1100 \degree C and 850 \degree C and subsequently aged at 550 \degree C for 24 h. The lower temperature rolling resulted in a yield strength increment of 299 MPa while still retaining an elongation to failure of over 30\%. The large improvement in strength was attributed to an increase in residual dislocation density which was retained even after the ageing heat treatment. A homogeneous precipitation of $\kappa$-carbides in both samples also showed that the high residual dislocation density did not adversely affect precipitation kinetics. These findings demonstrate that the tensile properties of this class of steel can yet be improved by optimising hot rolling process parameters.

The remarkable efficiency of chemical reactions is the result of biological evolution, often involving confined water. Meanwhile, developments of bio-inspired systems, which exploit the potential of such water, have been so far rather complex and cumbersome. Here we show that surface-confined water, inherently present in widely abundant and renewable cellulosic fibres can be utilised as nanomedium to endow a singular chemical reactivity. Compared to surface acetylation in the dry state, confined water increases the reaction rate and efficiency by 8 times and 30%, respectively. Moreover, confined water enables control over chemical accessibility of selected hydroxyl groups through the extent of hydration, allowing regioselective reactions, a major challenge in cellulose modification. The reactions mediated by surface-confined water are sustainable and largely outperform those occurring in organic solvents in terms of efficiency and environmental compatibility. Our results demonstrate the unexploited potential of water bound to cellulosic nanostructures in surface esterifications, which can be extended to a wide range of other nanoporous polymeric structures and reactions., The efficiency of chemical reactions in biological systems is often connected to the properties of confined water, but the developments and applications of artificial mimicking systems are impeded by the complexity of the biological systems. Here, the authors show how surface bound water in nanoporous cellulosic fibers can increase the reaction rate of surface acetylation reactions and enable regioselectivity of the reaction

The aim of the present study was to evaluate the effect of Compound 21 (C21), a selective AT2R agonist, on the prevention of endothelial dysfunction, extracellular matrix (ECM) remodeling and arterial stiffness associated with diet-induced obesity (DIO). Five-week-old male C57BL/6J mice were fed a standard (Chow) or high-fat diet (HF) for 6 weeks. Half of the animals of each group were simultaneously treated with C21 (1 mg/kg/day, in the drinking water), generating four groups: Chow C, Chow C21, HF C, and HF C21. Vascular function and mechanical properties were determined in the abdominal aorta. To evaluate ECM remodeling, collagen deposition and TGF-β1 concentrations were determined in the abdominal aorta and the activity of metalloproteinases (MMP) 2 and 9 was analyzed in the plasma. Abdominal aortas from HF C mice showed endothelial dysfunction as well as enhanced contractile but reduced relaxant responses to Ang II. This effect was abrogated with C21 treatment by preserving NO availability. A left-shift in the tension–stretch relationship, paralleled by an augmented β-index (marker of intrinsic arterial stiffness), and enhanced collagen deposition and MMP-2/-9 activities were also detected in HF mice. However, when treated with C21, HF mice exhibited lower TGF-β1 levels in abdominal aortas together with reduced MMP activities and collagen deposition compared with HF C mice. In conclusion, these data demonstrate that AT2R stimulation by C21 in obesity preserves NO availability and prevents unhealthy vascular remodeling, thus protecting the abdominal aorta in HF mice against the development of endothelial dysfunction, ECM remodeling and arterial stiffness.

Background While many factors involved in the etiology of developmental dysplasia of the hip (DDH), one of which is the hormone relaxin. Relaxin concentrations in patients with DDH may lead to pathodynamic changes during hip development by altering the physiological nature of the ligament, as well as by long-term exposure to relaxin during pregnancy. Our objective in this study was to determine the number of relaxin receptors in the ligamentum teres and their role in causing DDH. Methods We identified 26 infants between birth and 3 years of age who had undergone open reduction for DDH between 2010 and 2012. 12 hips of 12 miss abortus fetus between 20 to 35 weeks of gestation were used as control group. Specimens obtained from two groups were stained with Relaxin-2 antibody, and the amount of staining for relaxin receptors was determined using an ordinal H score. Results The mean (SD) H scores of infants with DDH were significantly higher than those of controls: 215 (59) versus 52 (48); P = 0.00; 95% CI. Statistically significant difference between the two groups in terms of gender was not found. Conclusion As a result, increased number of relaxin receptors in the ligamentum teres could be a risk factor for DDH. Level of evidence Level 2, Prospective comparative study.

In this study, the fresh properties, fracture energy, compressive strength, and flexural strength of self-compacting concrete including glass or basalt fibers were examined, and the effect of fibers on these properties were studied comparatively. For this purpose, fibers having three different lengths (6, 12, and 24 mm) were used in two different contents (2 and 4 kg/m3). The workability of concrete mixtures decreased with fiber addition. The negative effect of basalt fibers on workability was greater than that of the glass fibers. The reduction in flow diameter was up to 40% and 44% as well as the reduction in L-box ratio was up to 41% and 48% in glass and basalt fiber mixtures, respectively. While the fiber addition generally reduced the compressive strength, it increased the flexural strength and fracture energy significantly. Increase in flexural strength was up to 58.6% in glass fiber and 43.5% in basalt fiber mixtures. The fracture energies of glass and basalt fiber mixtures were up to 55.1% and 30.4% higher than that of the control mixture, respectively. © 2021 American Society of Civil Engineers. 2-s2.0-85118297261

This human cadaver study investigated whether flexor tendon repairs performed with round-bodied needles had a higher risk of pull-out compared with those performed with cutting needles. Forty human cadaver tendons were repaired (20 with each type of needle), subjected to tensile traction testing and evaluated by failure load and mode of failure. The average failure load was 50 N (SD 13 N) for tendons repaired with round-bodied needles, compared with 49 N (SD 16 N) for tendons repaired with cutting needles. Round-bodied needles resulted in more suture pull-out (18 out of 20 tendons) than cutting needles (6 out of 20 tendons). We found no differences in failure load, but significant differences in the mode of failure between round-bodied and cutting needles when used for cadaveric flexor tendon repair.

In this study, the hardness and surface roughness of selective laser-melted parts have been evaluated by considering a wide variety of input parameters. The Invar-36 has been considered a workpiece material that is mainly used in the aerospace industry for making parts as well as widely used in bimetallic thermostats. It is the mechanical properties and metallurgical properties of parts that drive the final product’s quality in today’s competitive marketplace. The study aims to examine how laser power, scanning speed, and orientation influence fabricated specimens. Using ANOVA, the established models were tested and the parameters were evaluated for their significance in predicting response. In the next step, the fuzzy-based JAYA algorithm has been implemented to determine which parameter is optimal in the proposed study. In addition, the optimal parametric combination obtained by the JAYA algorithm was compared with the optimal parametric combination obtained by TLBO and genetic algorithm (GA) to establish the effectiveness of the JAYA algorithm. Based on the results, an orientation of 90°, 136 KW of laser power, and 650 mm/s scanning speed were found to be the best combination of process parameters for generating the desired hardness and roughness for the Invar-36 material.

The current economic and ecological situation encourages the use of steel to push the technological limits and offer more cost-effective products. The enhancement of steel properties like wear, corrosion, and oxidation resistance is achieved by the addition of small amounts of chemical elements such as Cr, Ni, Si, N, etc. The steel surface can be protected by different treatments such as heating and coating, among others. For many decades, coatings have been an effective solution to protect materials using thin hard films. Several technologies for thin film deposition have been developed. However, some of them are restricted to certain fields because of their complex operating conditions. In addition, some deposition techniques cannot be applied to a large substrate surface type. The magnetron sputtering deposition process is a good option to overcome these challenges and can be used with different substrates of varying sizes with specific growth modes and for a wide range of applications. In this review article, we present the sputtering mechanism and film growth modes and focus on the mechanical and tribological behavior of nitride thin films deposited by the magnetron sputtering technique as a function of process conditions, particularly bias voltage and nitrogen percentage. The biomedical properties of transition metal nitride coatings are also presented.