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This study investigated the impact of temperature, time, and homogenisation on the transient liquid phase bonding of Inconel 617 to stainless steel 310, employing AWS BNI2 foil as an interlayer. Nine test series were conducted at temperatures of 1050 °C and 1100 °C, with bonding durations ranging from 10 to 60 min. The homogenisation process was carried out on specimens that underwent full isothermal solidification at a temperature of 1170 °C for 180 min. The microscopic analysis indicated that extending the time and raising the bonding temperature resulted in the extension of the isothermal solidified zone, accompanied by a reduction in the quantity of eutectic phases. Complete isothermal solidification was seen exclusively in samples bonded at temperatures of 1050 °C for 60 min and 1100 °C for a duration of 50 min. The size of the diffusion-affected zone expanded as the bonding temperature and duration rose, but the presence of brittle intermetallic phases diminished. The microstructure of the homogenised sample indicated that the diffusion-affected zone had been almost completely eliminated. Hardness variations indicated heightened hardness in the diffusion-affected zone (DAZ) and athermal solidified zone (ASZ). Shear strength is maximised in homogenised specimens with minimised ASZ.

Detoxification of solution and beer from aflatoxins B1 and G1 using layered double hydroxides is the focus of this study. The aluminum-magnesium layered double hydroxide (Al-Mg LDH) is selected in its calcined and non-calcined forms to evaluate the influence of calcination on detoxification. They were produced using the co-precipitation method and used in contaminated solutions and beer. Characteristics of the adopted adsorbents were studied by XRD, FTIR and SEM methods. Effects of quantity of the adsorbents, exposure time, and initial content of aflatoxin were investigated. Moreover, effects of the adsorbents on the properties of beer were studied. The non-calcined form of Al-Mg LDH was not able to adsorb aflatoxins B1 and G1 considerably. On the opposite, its calcined form exhibited more than 90% adsorption just in less than one hour in solutions and in less than 4 hours in the beer samples. The reason is pointed to the fact that calcination of Al-Mg LDH considerably enhanced characteristics of the adsorbent. It almost doubled surface area of the material, increased its total pore volume over 54%, and added to its pore size over 35%.

Objective(s): Scaffolds are considered as biological substitutes in bone defects which improve and accelerate the healing process of surrounding tissue. In recent years a major challenge in biomaterials is to produce porous materials with properties similar to bone tissue. In this study, the natural bioactive hydroxyapatite scaffolds with nano Diopside /Forstrite coating was successfully synthesized to be used in tissue engineering applications. Materials and Methods: The spongy part of bovine bone was cut and the subsequent sintering temperature was applied for fabrication of natural hydroxyapatite. Then the scaffolds were coated with 30 wt% nano-Diopside/Forstrite composite slurry. The scaffolds were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectroscope (EDS).Results: In the present study, the mechanical properties of natural HA scaffold were improved when coated with a composite nmaed Diopside/Forstrite ceramic. The optimum properties were evaluated for the scaffolds containing 30 wt% composite ceramic coating. The pore size of the obtained scaffold was measured to be in the range of 300-400 nm. Compressive strength and porosity of the composite scaffold were approximately 1.5±0.2 MPa and 93±1.1 MPa, respectively.Conclusions: Based on the mechanical and bioactivity result, the natural bioactive hydroxyapatite scaffolds with nano Diopside /Forstrite coating showed improved mechanical properties, pore size, porosity content and apatite formation ability whcih can be a promising candidate for bone tissue engineering applications.

Bone marrow-derived mesenchymal stem cells (MSCs) offer a promising therapeutic method for cardiac tissue regeneration. However, to monitor the fate of MSCs for tissue repair, a better stem cell delivery carrier is needed. Developing a unique injectable and shear-thinning dual cross-linked hybrid hydrogel for MSC delivery for cardiac tissue engineering is highly desirable. This hydrogel was synthesised using guest: host reaction based on alginate-cyclodextrin (Alg-CD) and adamantane-graphene oxide (Ad-GO). Here, the role of macromere concentration (10 and 12%) on the MSC function is discussed. Our hybrid hydrogels reveal a suitable oxygen pathway required for cell survival. However, this value is strongly dependent on the macromere concentrations, while the hydrogels with 12% macromere concentration (2DC12) significantly enhanced the oxygen permeability value (1.16-fold). Moreover, after two weeks of culture, rat MSCs (rMSCs) encapsulated in Alg-GO hydrogels expressed troponin T (TNT) and GATA4 markers. Noticeably, the 2DC12 hydrogels enhance rMSCs differentiation markers (1.30-times for TNT and 1.21-times for GATA4). Overall, our findings indicate that tuning the hydrogel compositions regulates the fate of encapsulated rMSCs within hydrogels. These outcomes may promote the advancement of new multifunctional platforms that consider the spatial and transient guidelines of undifferentiated cell destiny and capacity even after transplantation for heart tissue regeneration.

Introduction: The use of earthen materials is common in hot and dry areas around the world, due to a cheap, abundant and easy access to materials. Today, the use of earthen materials is common in urban and rural areas in developing countries. In Iran earthen materials have partly shaped our architectural culture and identity. Kahgel is one of the oldest traditional plastering and mortars in Iran, which has been used to insulate the roof and facades of buildings from moisture and rainfall. Although the importance of processing and curing mortars and plasters is well known among architecture and building professionals and builders, no research has been conducted on the effect of processing time upon the physical quality and mechanical properties of traditional mortars, especially Kahgel. The main purpose of this study is to evaluate the importance and duration of curing process on the physical and mechanical properties of Kahgel using experimental methods. Material and methods: As the first step, soil samples were taken from different areas of Isfahan and then these samples were examined using different experimental methods. Then the most appropriate soil sample in terms of physical and mechanical properties was selected. Several samples of Kahgel mortars were produced using the selected soil sample and different percentages of straw fibers. For these kahgel samples the compressive strength, tensile strength, linear shrinkage and cracking were measured to determine the most appropriate combination of selected soil mixed with straw fibers. In the second phase of the study, the type of soil and straw percentage were not changed, while the processing time was considered as an independent variable. The new Kahgel samples were prepared by a variety of processing time and then their compressive strength and tensile strength were measured to examine the effect of the curing time on the mechanical properties of Kahgel. Results: The results indicate that the compressive strength dropped with increasing straw fiber content and increased with increasing soil content. The results of all the tests indicate that tensile strength of Kahgel increased with increasing straw fiber content up to 6 %, but the higher straw contents decreased tensile strength. The linear shrinkage of samples decreased with increasing straw fiber content. The results showed that the curing time of Kahgel affects its mechanical properties, especially compressive strength and tensile strength. Therefore, the mechanical properties of Kahgel can be improved by increasing the duration of curing time.

Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains’ dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld; at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal.

Forsterite nano crystallite was synthesized by mixing talc and MgCO₃ in a ball mill for ten hours and then heating at 1000°C for ten minutes. Using twin-screw extrusion and then compression molding, an ultra high molecular weight polyethylene (UHMWPE) reinforced by forsterite nano crystallites with volume fraction of 0/5 was produced as a composite sheet. Scanning electron microscopy images showed homogeneous distribution of forsterite particles in the UHMWPE matrix with size scale of less than 1 μm. In vitro evaluation test in simulated body fluid (SBF) solution revealed the bioactivity of this composite. Mechanical properties of the produced composite were then evaluated using standard tensile test. Results showed that this composite has a strong Young modulus which is ten times higher than that of pure UHMWPE. In addition, the excellent toughness of pure UHMWPE was approximately maintained using 0/5 volume fraction of forsterite nano crystallite which is gained by over 300% fracture strain.

In present study the pure forsterite-diopside nanocomposite powder was successfully synthesized by the economical method of mechanical alloying and subsequence sintering, for the first time. The starting economical materials were talc (Mg3Si4H2O12), magnesium carbonate (MgCO3) and calcium carbonate (CaCO3) powders. The prepared powder was characterized by thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed preparation of forsterite- diopside nanocomposite powder after 10 h mechanical alloying and sintering at 1200oC for 1 h. The powder crystallite sizes and agglomerated particle sizes were measured about 73 +/- 4 nm and 0.3 - 4 μm, respectively. Absence of enstatite that causes a reduction in mechanical and bioactivity properties of forsterite ceramic, is an important feature of produced powder.