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The polymer electrolyte membrane (PEM) fuel cells flow fields channels serve the same roles as nutrient and reactant circulation systems in plants and animals, so bio-inspired flow field channels with a similar could improve reactant uniform transport efficiency and boost fuel cell performance. In this analysis, the lung channel configuration of a humane lung and a tree leaf bio-inspired flow field channels are used as an anode and cathode bipolar plate. A channel model is developed for three new flow field patterns designs: leaf design, lung design and triple-serpentine. It has been observed that the performance improvement in terms of power in the bio-inspired flow field is 13.32% more than the triple serpentine. This indicates the bio-inspired design has good performance than other flow field design. Further a parametric steady is carried out experimentally to study the effect of cell operating temperature, anode and cathode humidity, hydrogen and oxygen flow rate on the cell performance.

The Proton Exchange Membrane Fuel Cells (PEMFCs) performance is improved by flow field channel design. The flow field reactant distribution geometry on PEMFCs is primarily influenced by the perceived effect of pressure and transmission characteristics of reactant flow fields on the efficiency of fuel cells. Nutrients distributed in the biological branching structures systems found their optimum arrangement have more efficiently in each part. The flow fields design channels in polymer electrolyte membrane (PEM) fuel cells serve the same roles as nutrient transport systems in plants and animals, so bio-inspired flow fields design with a similar could maximize reactant transport efficiency and improve fuel cell performance. In this analysis, the lung channel design of a humane lung and a tree leaf bio-inspired flow field design is used for the flow fields of the anode and cathode bipolar plates. SOLIDWORKS produces a 3-D numerical CFD design for four new flow field pattern designs: leaf design, lung design, single-serpentine, and triple-serpentine. The model is simulated using ANSYS FLUENT-15.0 software to obtain pressure distributions in the flow field, concentration profiles of hydrogen on anode and oxygen on cathode channel, current flux density on the membrane, water concentration on the membrane, water generating in a cathode channel, the polarization curve and the power curve. It is observed that bio-inspired leaf and lung design performs better than serpentine flow field channels. So, leaf and lung design can be used in mopeds and automobiles to enhance electrical efficiency and at the same time reduce fuel consumption.

The purpose of this study is to observe the change in the microstructure of the magnesium AZ91 alloy with the help of refinement of the grain structure due to Friction Stir Processing (FSP), result...

The main objective of this research was to control the formation of biofilm on the urinary catheter because biofilm infections spread in the urethra and sometimes become the cause of death. zinc ox...

The demand for aluminum is very high worldwide because of its high strength, low density, and high electrical and thermal conductivity. Aluminum and its alloys are widely used in automotive, aerospace, packaging, kitchen utensils, construction, electrical cabling, etc. To satisfy the high demand, high production of aluminum and its alloys is essential. However, the sources of primary aluminum (aluminum extracted from ores) are limited. Hence, the efficient recycling of aluminum is vital. Conventional casting is often used to recycle aluminum and its alloys, although the efficiency of such a method is very low. The researchers are therefore working to develop highly efficient aluminum recycling techniques. Powder metallurgy is one of the novel techniques for recycling aluminum due to its high use of materials, its low energy consumption, and its quasi-final production of forms. The powder metallurgy technique is also beneficial in the manufacture of aluminum-based metal foams. There are various ways to prepare aluminum-based metal foams using the powder metallurgy technique. Aluminum-based metal foams are utilized in crashworthiness applications because of their remarkable properties, like low density and high energy absorption capacity. In this work, a study on various methods of recycling and foaming of aluminum-based materials by powder metallurgy is performed. The parameters of the powder metallurgy process, such as the compaction pressure, the weight or density of the reinforcements, and the type of reinforcement, strongly influence the recycling and foaming of aluminum. In this work, the effect of compaction pressure, weight or density fraction of reinforcements, and type of reinforcing agent on the recycling and foaming of aluminum and its alloys was investigated.

Welding and riveting are the two fundamental joining processes for metals. Welding joints have high strength than the riveting joints. But there is a high heat-affected zone in welding. The heat-affected zone is the reason for the stress concentration and pre-mature failure. The heat-affected zone and other properties (i.e., microstructural, mechanical, and corrosion) of a welded joint depends on the welding parameters. In the present work, a re-analysis of the effect of welding parameters is done on the microstructural, mechanical, and corrosion properties of the inert tungsten gas welded materials. It was observed that the grain coarsening occurred in the heat-affected zone, while in the fusion zone, grain refinement took place. Hence, the coarsening of grains reduced the hardness and tensile strength of the material in the heat-affected zone. Heat affected zone can be reduced by reducing the current, but the reduction of current reduces the penetration.

Aluminium matrix composites are the special class materials used in automobile, aerospace, nuclear, and packing industries. High demand for these materials is due to high electrical conductivity, high thermal conductivity, high strength, high wear resistance, high ductility, and excellent machinability. Stir casting, friction stir processing, and powder metallurgy are common techniques used for the fabrication of Aluminium matrix composites. Some of the advantages of the powder metallurgy technique such as, high material utilization, less power consumption, and less scrap, etc.; are the main reasons for the inclination of researchers towards the use of this technique for the fabrication of Aluminium matrix composites. The Powder metallurgy process parameters, i.e., compaction pressure, sintering temperature, and sintering time, highly influence the physical and mechanical properties of Aluminium matrix composites fabricated by powder metallurgy. The type and weight fraction of reinforcement also have a significant effect on the physical and mechanical properties of Aluminium matrix composites. In the present study, re-investigation has been done on the effect of the above parameters on the physical and mechanical properties of Aluminium matrix composites. During the literature survey, it was observed that, compaction pressure is the most influencing parameter. The Density and porosity can be controlled effectively by controlling the compaction pressure. For Aluminium-based materials fabricated by powder metallurgy, the optimum range of compaction pressure, sintering temperature, and sintering time is 600–700 MPa, 520–600 °C, and 3–4 h, respectively.

The properties of the alloys and metal matrix composites processed by friction stir processing are significantly affected by some fundamental parameters like; type of reinforcement, weight or volume % of reinforcement, number of passes, rotational speed, etc. The current study was done to explore the effect of these parameters on the mechanical properties of aluminium-based materials processed by friction stir processing. It was observed during the literature survey that the strength and hardness increased by 30%–40% after processing Al-based materials up to 3–4 friction stir processing passes. The wear rate decreased by 25%–30% after processing the Al-based materials up to 3–4 friction stir processing passes. The wear rate gets reduced on increasing the value of rotational speed (about 60%–70% reduction in wear rate after processing the aluminium based materials at a rotational speed 1300 rpm–1500 rpm). As the grain size increases on increasing the tool rotational speed, strength and hardness decreases. On increasing the transverse speed, there is a reduction in the grain size. Hence, the strength and hardness increase with an increase in the transverse speed.

In this study, a re-investigation on metal matrix composite fabricated by powder metallurgy route has been done. Copper based metal matrix composite has the wide applications because of their good electrical, thermal and mechanical properties. Copper has good strength and resistance to corrosion. But in order to increase the properties of copper, copper matrix composite has been fabricated by powder metallurgy process. The composites materials fabricate by powder metallurgy process has various property such as hardness, tensile strength, compressive strength, toughness, fatigue strength. These properties depend on some parameter such as reinforcement, pressure during powder compaction, temperature of sintering, holding time at sintering temperature, particle size, volume fraction of reinforcement etc. This study shows investigation of effect of various parameter on mechanical property of copper-based metal matrix composites. It has shown that due to presence of secondary phase hard particle like alumina, SiC, titanium carbide, TiO2 in copper metal matrix increase hardness, strength and reduce density. Reduction in density is very important in order to fabrication of automobile and aircraft parts. The strength and hardness increase with addition of SiC but ductility is reduced. It is shown that sintering temperature and sintering time is most important parameter because it highly influences hardness and strength.

As the world is shifting towards renewable sources of energy, the demand for copper is increasing due to its excellent electrical and corrosion resistance properties. Although, because of low strength and wear resistance, the use of pure copper is quite limited. Various reinforcing materials are added to the Cu matrix to fabricate high-strength and wear-resistant copper matrix composites. Powder metallurgy is the most commonly used metal matrix composite fabrication method for Cu-based materials. Properties of a powder metallurgy product depend on the process parameters such as compaction pressure, sintering temperature, sintering time, type and rate of reinforcement, size of matrix and reinforcing elements, etc. In the present work, the influence of the above-mentioned parameters on mechanical and electrical properties of copper-based materials produced by the powder metallurgy method is reviewed in detail. The literature survey revealed that SiC, graphite (Gr), TiC, and graphene (Gn) are the most commonly used reinforcement additives in the Cu matrix for improvement of the strength and wear resistance of Cu-based materials. It has been established that the strength and wear resistance increase after the addition of the mentioned reinforcers, although the electrical conductivity decreases. For enhanced mechanical and electrical properties, a 4–6% weight fraction of micron-sized reinforcers, such as SiC, TiC, and graphite, and a 0.25–1% weight fraction of nano-sized reinforcers, such as CNTs and graphene, are considered the optimum reinforcement range for the Cu-matrix. Small particle size of 3–5 μm of matrix material (Cu) improves mechanical and electrical properties. The size of nano-reinforcers, such as CNTs, should be sufficiently larger (30–50 nm) to avoid agglomeration. Besides, factors contributing to better properties are the optimum range of compaction pressure of 550–650 MPa, sintering temperature of 800–900°C, and sintering time of 60–90 min.

In the present study, a reanalysis of Magnesium based metal matrix composites made by powder metallurgy has been done. The Properties of the powder metallurgy products are highly influenced by some basic parameters like; type of reinforcement, weight or volume fraction of reinforcement, compaction pressure, sintering temperature and sintering time, etc. That is why the present study was focused to investigate the effect of these parameters on the mechanical properties of magnesium based Metal Matrix Composites (MMCs). It was observed that the hard ceramic particles like Al2O3, SiC, B4C, TiO2, TiC and etc. are reinforced in the magnesium matrix to enhance the strength, hardness and other properties. The strength and hardness increases on addition of these hard ceramic particles but ductility is reduced. It has been also observed that the metallic reinforcement like Titanium increases both the strength as well as the ductility of Magnesium based MMCs.

The present attempt is focused to investigate the outcome of charcoal particles loading on thermal properties of sisal composite. Sisal fibres were reinforced into epoxy matrix with a constant length (10 mm) and constant wt.% (30) to prepare the composites by hand lay-up method . Charcoal particles were homogeneously mixed into epoxy resin using magnetic stirrer at 1000 rpm with varying percentages (2, 4, 6, and 8). Thermal properties of prepared composites were analyzed using thermogravimetric analysis (TGA) to measure the thermal stability and dynamic mechanical analysis (DMA) to measure the storage modulus, damping, loss modulus and glass transition temperature. The results showed a positive effect of incorporation of charcoal particles into epoxy on the thermal properties of sisal composites. In addition, thermal stability, glass transition temperature and storage modulus were also improved due to incorporation of charcoal particles.

Copper Matrix Composites (MMC) have been widely used in electrical appliances, automobiles, aerospace, bearing and bushes because of the better mechanical properties, solid lubrication and hardness. With the low percentages of graphite in Copper–Graphite–TiO2, it can also be used for the manufacturing slip rings, switches, connectors, relays and plugs. In the present work, efforts have been made for the preparation of Cu–Graphite–TiO2 metal matrix composites with six different compositions, i.e. (Pure Cu, Cu + 8%Gr, Cu + 6%Gr + 2%TiO2, Cu + 4%Gr + 4%TiO2, Cu + 2%Gr + 6%TiO2, Cu + 8%TiO2) using powder metallurgy techniques. Mechanical properties like compression strength and microhardness were studied. The ultimate compressive strength increases by 11.77% due to addition of 8% TiO2 in the pure Cu. It was observed that the addition of graphite into copper results in decrease of hardness value because of the soft nature of graphite. On the other hand hardness increases after addition of 8% TiO2.

Magnesium has extensive applications in aerospace, automotive, medical and other lightweight applications due to the fact that magnesium is the lightest structural metal with density 1.74 g/cc. However, magnesium has low mechanical strength, low hardness, poor resistance to corrosion and wear. To improve the poor properties of magnesium alloy, magnesium matrix composite has been synthesised by powder metallurgy technique. CNT and B4C reinforced Mg AZ91 hybrid composites with six different compositions (Pure Mg, Mg+2%B4C, Mg+0.5%CNT+1.5%B4C, Mg+1%CNT+1%B4C, Mg+1.5%CNT+0.5%B4C, Mg+2%CNT) were produced. The microstructural and mechanical properties of CNT and B4C reinforced Mg AZ91 hybrid composite has been investigated. It was observed that the maximum compressive strength (Ultimate compressive stress 196.25 MPa) was obtained for composition (i.e. Mg+1.5%CNT+0.5%B4C). The maximum hardness of 103.2 VHN was obtained for composition (i.e. Mg+2%B4C) as compared to Mg alloy AZ91 having 92.3 VHN.

The use of magnesium in the automobile and biomedical applications is increasing nowadays due to its lightweight and high specific strength but magnesium alloys have some drawbacks like low ductility, low absolute strength at higher temperature, low hardness, etc. In this research, Friction stir processing (FSP) has been used for improving the hardness and microstructural properties of magnesium AZ31 alloy. The changes in the properties have been observed at different tool rotations (580, 850 and 1160 rpm). It has been found that the size of the grains is maximum for the as-received sample, and its average size lies in between 47 and 69 µm and size of grains is minimum for the FS processed samples at 850 rpm and its average grain size lies in between 0.75 and 1.1 µm. The FS processed samples at 850 rpm showed an approximate 33–37% increase in the hardness.

Passive solar stills globally accepted as a well-known system to desalinate unkempt water at a low yield rate without degradation of ecology and environment. Enhancement techniques are available to increase its productivity at higher capital and distillate production costs. Multi-wick solar stills can be a better option to increase productivity and alleviate distillate production cost relatively at lower capital cost. This work is allied to the assessment of the incorporation of hanging wicks in basin-type solar stills on overall performance improvement based on yield, energy, exergy, energy matrices, exergoeconomic, and enviroeconomic methodologies. Four modified solar stills, namely, modified basin type single slope solar still (MBSSSS); modified basin type double slope solar still (MBDSSS); modified basin type single slope multi–wick solar still (MBSSMWSS); and modified basin type double slope multi–wick solar still (MBDSMWSS) are designed and fabricated. Experimental observations are taken throughout the year at the climatic conditions of Prayagraj, India. Results revealed that the annual yield and exergy output; average annual energy and exergy efficiency of MBSSMWSS and MBDSMWSS (with black cotton wick (BCW)) are found as 1172.03 and 2583.99 kg; 100.70 and 97.36 kWh; 23.93% and 28.78%; 2.579% and 2.233%, respectively, in comparison to 861.55 and 1551.48 kg; 72.96 and 66.32 kWh; 15.08% and 17.48%; 1.765% and 1.160%, obtained for MBSSSS and MBDSSS, respectively. Based on energy and exergy, lower energy payback time; higher energy production factor; and higher life cycle conversion efficiency are found as 0.637 and 8.255 years; 1.568 and 0.121; 0.2807 and 0.0262 (life span of 50 years) for MBDSMWSS and MBSSMWSS, respectively, with BCW at lower water depth. Among the modified solar stills, minimum cost of distilled water, least payback period, higher CO2 reduction benefit and carbon credits (energy basis) are found for MBDSMWSS. The exergoeconomic parameter is found higher for MBSSMWSS.

In the present work, Aluminium alloy sheets graded as Al6061 having 6 mm thickness were TIG welded as a butt joint. In order to modify the microstructure, the joint of welded samples were subjected to friction stir processing (FSP). The effect of FSP on the microstructure in the welded and heat affected region (HAZ) was characterized by optical microscopy. Further, the mechanical strength, hardness and fatigue life was determined through mechanical test, hardness test and fatigue test. The fatigue life tests were performed at constant amplitude loading by taking stress ratio equals to zero. It has been found that the FSP increases the tensile strength approximately 5–13% whereas hardness 5–10%. Similarly, there has been found approximately 30–60% improvement in fatigue strength. It is attributed that such kind of changes were found due to grain refinement in the welded region and its vicinity. Other reasons might be due to the modification in geometry of weld toe. It has been observed that the weld defects like porosity, hot cracking and lack of wetting have been also reduced.