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Energy harvesting devices and nano-generators using flexible piezoelectric materials has gained more attention since the last decade. In the present study, the suitability of using electrospun neat polyvinylidene fluoride (PVDF) and PVDF/aliphatic hyperbranched polyester of 3rd generation (HBP-G3) blend (90/10) nanowebs as piezoelectric sensors were studied. In the first step, synthesis of HBP-G3 was carried out by one-shot melt-polycondensation method using pentaerythritol (as core molecule), dimethylol propionic acid (as monomer) and p-toluene sulphonic acid (as catalyst). The synthesized HBP-G3 was characterized using FTIR, NMR, DSC and TGA. Further, electrospinning of neat PVDF and PVDF/HBP blend (90/10) were carried out and the nanoweb samples were analysed using FT-IR, XRD and SEM. Finally, the nanoweb samples were used in the fabrication of piezoelectric sensors and their peak-to-peak output voltage (Vp-p) measured. Compared to neat PVDF (Vp-p = +0.95 V), PVDF/HBP-G1 (90/10) blend exhibited higher Vp-p (+1.62 V), and has the potential for use in energy-harvesting applications.

Since the last decade, many research groups are working towards improving the β-crystallinity in PVDF by blending with other polymers. In the present study, we have focused on the synthesis of aliphatic hyperbranched polyester of generation-1 (HBP-G1), solution-blending of PVDF with HBP-G1 (90:10 ratio), their electrospinning and piezoelectric measurements. From FTIR analysis of the electrospun samples, PVDF/HBP (90:10) sample was found to exhibit higher β-crystalline peak compared to neat PVDF. Further, the samples were used for fabricating piezoelectric sensors and measured for their peak-to-peak output voltage (Vp-p). Among them, PVDF/HBP-G1 (90:10) sample exhibited higher Vp-p (+1.76 V) compared to neat PVDF (100:0, +0.95 V). The data obtained from this study is evidence that the PVDF/HBP-G1 (90:10) based sensor can be efficiently used for energy-harvesting applications, which signifies the importance of this study.

Constructions are debilitated by crack. At the point when the Crack size builds, the construction turns out to be exceptionally failed; at last the design may Crackdown because of moment Crack. Thusly, Crack recognition is vital. The target of this investigation is free vibration examination of cracked cantilever beam utilizing FEM. This research has focused on both the cases namely single edge crack as well as double edge crack and the frequency characteristics are determined for various mode of crack location and the crack depth by ANSYS software.

Submarine pressure hulls, fire-tube boilers, vacuum tanks, oil well casings, submersibles, underground pipelines, tunnels, rocket motor casing, etc., are some of the examples of thin cylindrical shell structures which collapse due to buckling under uniform pressure. To enhance the buckling strength of bare cylindrical shells, one of the best solutions is to stiffen them with ring stiffeners. In this work in order to predict the shell instability failure mode (SIFM) and general instability failure mode (GIFM) FE models are generated and analysed using buckling analysis of general-purpose FE software ANSYS. The numerical results obtained using FE analysis are compared with published analytical and experimental results. Hence in the present study efforts are taken to develop FE models to predict global and shell instability failure modes of externally ring stiffened cylindrical shells by using linear FE analysis. It is proposed to use full/half bare cylindrical shell FE models (L/R ratio upto 200) to determine SIFM and FE models with shell281- Beam189 (for stiffeners) can be used to determine GIFM. The developed FE models are validated by comparing numerical results with experimental results published by Seleim and Roorda [25] . By using both proposed FE models it is possible to predict the failure modes namely SIFM and GIFM, comparing their values of critical buckling pressures. The lower pressure value can indicate the possible failure mode.

The design of cost-effective and highly efficient electrocatalysts for oxygen evolution reaction (OER) remains a key element in pursuit of developing sustainable renewable energy conversion and sto...

Zinc oxide nanoparticles (ZnO NPs) and binary ZnO–CuO nanocomposites (ZnO–CuO NCs) were prepared through a simple chemical co-precipitation route. The influence of copper (Cu2+) ions concentration (0.03, 0.06, 0.09, and 0.12 M) on optical, morphological, structural, and elemental characteristics of the ZnO–CuO NCs was examined by appropriate characterization techniques. The visible light reactive CuO created absorption shift to red region that minimized band gap of the ZnO–CuO NCs. The concentration of Cu2+ ions produced appreciable impact on size of the ZnO–CuO NCs. The dye-sensitized solar cell (DSSC) constructed using ZnO–CuO NC photoanode with Cu2+ ions concentration of 0.06 M generated a conclusive solar to electrical energy transformation efficiency of 2.56%, which was a 2.2-times greater over the DSSC encompassed pristine photoanode of ZnO NPs. The electrochemical impedance spectroscopy analysis revealed the longer lifetime of the photogenerated electrons and reduction in the charge recombination rate in the ZnO(0.44)–Cu(0.06) NC photoanode based DSSC. Furthermore, the ZnO(0.44)–Cu(0.06) NC disclosed substantial photocatalytic activity towards methylene blue dye degradation that could be chiefly credited to its particles size induced visible light absorption property.

An electroporator is an instrument used for delivering electrical pulses to a tumor. In this work, an electroporator consisting of three main system blocks, namely High Voltage (HV) source, nanosecond (ns) switching, and pulse generation, was designed, developed, and evaluated to generate high voltage ns pulses to treat tumors. The high-voltage source block was used to convert the 9.6V DC from the battery to a variable HV output and store this charge for later use. The ns switching block contained a MOSFET-based low-side switch which applies short ns pulses to the load. The pulse generation block generates short ns pulses and supplies the adequate current to turn on the MOSFET at a quicker rate aiding the application of these pulses to the load. This process was simulated using PSpice software and the results are presented.

Natural fibers are being used for an extended period in automobiles, aviation, and marine applications. This work aims to study the prominent effect of barium sulfate (BaSO4) and fly ash particles ...

This paper aimed to study the influence of the substrate and the arc voltage on the structure and functional properties of the NiTi shape memory alloy produced by wire arc additive manufacturing (WAAM). The gas metal arc based WAAM process was used for the deposition of 3-layered NiTi walls on a titanium or steel substrate at different arc voltages using a Ni50.9Ti49.1 wire. It was found that in the sample deposited on the Ti substrate, the Ti2Ni phase appeared and the Ti concentration in the NiTi phase increased to 50.5 at.%. An increase in the arc voltage influenced the volume fraction of Ti2Ni precipitates in the 1st layer but hardly affected the chemical composition of the NiTi phase in all layers as a result, the martensitic transformation temperatures do not depend on the arc voltage. Therefore, the deposition of the Ni-rich NiTi wire on a Ti substrate allowed for the production of the Ti-rich NiTi walls undergoing the martensitic transformation and demonstrated the shape memory behaviour at high temperatures. An increase in the arc voltage hardly affected the shape memory behaviour but decreased the strain up to failure due to an increase in the volume fraction of the brittle Ti2Ni phase, which in turn facilitated the formation of cracks during deformation. In the sample deposited on the steel substrate, the NiTiFe solid solution and Ti-C, Ni3Ti4, and Ni3Ti2 precipitates formed in the 1st layer. An increase in the arc voltage led to an increase in the Fe concentration in the NiTiFe solid solution from 17 at.% to 42 at.% in the 1st layer. From layer to layer, the Fe concentration decreased; however, it remained larger than 1.5 at.% and completely suppressed the martensitic transformation and the shape memory effects in the NiTi sample deposited on the steel substrate.

Electrochemical machining is a nonconventional machining process in which the metal removal is achieved by the electricity and chemical solution known as an electrolyte. It is the reverse electrolysis process where the application of electricity facilitates the current travel in between anode and cathode. The mechanism of the ion movement is similar to the electrolysis process. Electrochemical machining (ECM) is a type of advanced machining process which employs electricity to perform the machining process on the workpiece. It is also known as a reverse electroplating process where metal removal is achieved instead of metal deposition on the metal surface. There are various parameters that affect the metal removal process in the ECM process, such as electrolyte, power supply, workpiece material, and tool material. The electrolyte is one of the key factors impacting the machining rate, surface finish, and reliability of the produced parts. In this project, a brief study is carried out regarding the electrochemical process and the electrolytes where the properties, functions, merits, and demerits are evaluated. The impact of the various electrolytes and their suitability for machining of various metals is also discussed. The findings of the effect produced by using the mixture of the electrolyte in the electrochemical machining process are discussed in this project. The effects of the complexing agents on the electrolyte and the electrochemical process as a whole are also reviewed.

Fibrous construction and combination of different fine/coarse fibres, bonding techniques and the directional arrangement of fibres are the significant performance parameters of the unique character...

Purpose The purpose of the study is to design economical shock tube. It is an instrument used for experimental investigations not only related to shock phenomena but also for the behavior of the material when it is subjected to high-speed flow. The material used here in this shock tube is stainless steel ss304 and aluminum. A shock tube consists of two sections, namely, the driver and the driven. The gas in the driven and driver is filled with atmospheric air and nitrogen, respectively, under the predominant condition. Design/methodology/approach The focus of the study is on the design and fabrication of shock tubes. a shock tube is a research tool to make an aerodynamic test in the presence of high pressure and temperature by generating moving normal shock waves under controlled conditions. Findings The main necessity for instrumentation in the shock tube experiment is to know the velocity of the moving shock wave from which the other parameters can be calculated. the pressure transducers are located in the shock tube in various locations to measure aerodynamic parameters in terms of pressure. Originality/value The main objective of this project work is to make an experimental setup to produce supersonic velocity with the readily available material in the market in a highly safe manner.

Objective: To investigate the physical and strength properties of mortar using locally available mineral admixture. Methodology: The compressive strength of the mortar at different temperatures was found. Setting time, consistency, and porosity were also studied by blending natural kaolinite and metakaolinite (MK) with cement in different proportions. An experimental work was carried out using control mix and adding kaolinite from 5% to 20% in ordinary Portland cement (OPC) at 5% equal intervals. Findings: The test results revealed that the use of natural admixtures such as Natural kaolinite (NK) and MK in OPC enhances the performance of the binder in mortar. The compressive strength enhancement of natural kaolinite cement–blended binder was comparatively lower than that of control mortar for all percentages whereas the mortar added to MK had increased strength. MK mortar with a 15% mix proportion was the optimum one to yield maximum compressive strength. Novelty: The present research work is focused on the partial replacement of metakaoline with temperature variant and the percentage of dosage used as a double variant parameter. Keywords: Natural kaolinite; Metakaolinite; Calcination; Apparent porosity; Compressive strength

This present work focused on investigating the thermal behavior and emission level of sapodilla oil mixed with diesel to an internal combustion (IC) engine. The behavior of the engine is measured via brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), heat release rate (HRR), cylinder pressure, and cumulative heat release rate (CHRR). The test results were evaluated with diesel fuel. Carbon deposits were low in sapodilla seed oil with slight variation of calorific value than standard diesel fuel. BTE value for case B20 is found to equal diesel fuel. For lower and higher blends, the cylinder pressures are lower than the diesel fuel. HRR decreased as increased of the blend ratio. Inferior blends of sapodilla are emitted lower HC and CO. The BTE of B100 works 88.13% efficiently, similar to diesel for low load conditions. When compared to diesel, a maximum NOx reduction of up to 30% was achieved while using the sapodilla blend. It is found that the oil derived from the sapodilla seed kernels will be the promising additive for fossil fuels for a greener environment.

Research towards solid polymer electrolytes based on biopolymers has grown extensively over the past years due to its abundance in nature, non-toxicity, low cost, and biodegradability. When compared to standard biopolymers, electrochemical study on natural gums is very limited. Therefore, in the present work, polymer electrolytes based on gum tragacanth have been prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), thermogravimetry, and transference number studies. The polymer-salt complex formation is confirmed using FTIR studies while XRD spectra reveal the amorphous nature of the polymer membranes. The highest conductivity of 9.161 × 10−3 S/cm was obtained for the film with 1 g of gum tragacanth and 0.5 g of ammonium thiocyanate. The Thermogravimetry study showed that the electrolyte is thermally stable. The transference number study confirmed that the main charge carriers are ions. The primary battery has been constructed using the prepared electrolyte, and the OCV was found to be 1.31 V.

Waste materials utilization as value-added materials and micro, nanoparticles inclusion is gaining huge attention. The sludge generated from the textile industry constitutes a high toxic compound and hazardous in nature. Currently, large quantities of solid sludge remain unattended and undisposed in various effluent plants, waiting to be disposed of at the landfills. In this study, the waste sludge generated from the textile industry was processed and reused as a substitute for cement material. The specimens prepared from the textile waste sludge along with nanoparticles were tested for durability and mechanical properties. The usage of textile sludge decreases the strength properties marginally until a replacement level of 10%. Beyond the addition of 10% textile sludge waste reduces the strength and durability properties significantly. Textile waste sludges were replaced for cement of varying proportions, i.e., 2.5%, 5%, 7.5%, 10%, 15% and 20%. The addition of alumina nanoparticles has dual effects, enhances the hydration properties and also acts as a filler material. The formation of calcium silicate hydrate gel was improved significantly due to the utilization of nano alumina. The optimum amount of alumina nanoparticles observed from the previous studies was found to be 3% by weight of cement due to high durability and mechanical properties. The combination of 10% textile waste sludge along with 3% nano alumina blended cement concrete leads to enhanced strength and durability characteristics as compared to all other concrete specimens and it was found to better eco-friendly construction material.

A vertical photonic crystal fiber (V-PCF) and horizontal PCF (H-PCF) are designed for the detection of sulfur dioxide (SO2) in this paper. A demanding numerical investigation is carried out in a wider range of wavelengths from 0.8 µm to 1 µm. SO2 is a major contributor to air pollution, which is responsible for asthma and cancer. The optical parameters are analyzed by using the Finite Element Method (FEM) which consumes a completely circular isotropic Perfectly Matched Layer (PML). The designed V-PCF sensor test is performed with different PML radius values, different elliptical constants for the inner cladding, the outer cladding layer, and the core. The higher relative sensitivity of 59.34% makes this proposed V-PCF a good design for SO2 detection.

Supersonic single-impinging jet flows are known to exhibit strong unsteadiness levels and acoustic signatures due to large-scale resonant motions. However, the flowfield characteristics of two such...

In this paper, a photonic crystal ring resonator (PCRR)-based optical demultiplexer is reported for Dense Wavelength Division Multiplexing (DWDM) applications. Diamond and silicon-dioxide are designed and simulated by an eight-channel PCRR. An average uniform spacing of 0.8 nm and 1.94 nm is obtained for the proposed demultiplexer, with silicon-dioxide and diamond, respectively. For the eight-channel PCRR structure, silicon-dioxide results in a maximum transmission efficiency of 91.48%. The quality factor is measured as 1613.336. Because of its light guiding mechanism, the ring resonator is found to be the most suitable and convenient for having dense wavelength division multiplexing amongst the different optical devices available based on photonic crystals.

Nickel–Titanium (Ni-Ti) shape memory alloy, commonly called nitinol alloys, finds its primary application in the production of biomedical implants, mainly because of itsrare properties such asshape memory, superelasticity and superior biocompatibility. Laser cutting is anon-traditional machining process for the production ofparts with close tolerances andcomplex geometry. Electrical discharge machining (EDM) of nitinol is associated with more heat-affected zone (HAZ) and recast layer thickness. This article aims to study nitinol’s machining characteristics by alaser source with good beam quality to have a less HAZ, recast layer and striations. Experiments were designed and carried out using central composite designs (CCD) by a pulsed Nd:YAG laser. Analysis based on the different parameters chosen was conducted to determine the parameters; effects, including laser power, frequency and cutting speed concerning the surface roughness. From the results, it is observed that the presence of HAZ is measured up to1. 48 mm from the machined surface. The topography analysis reveals that the striation is identified at high speeds, with less pulse overlapping by columnar micro channels, which can be reduced at high pulse frequency.

The friction stir welding (FSW) is found to be an effective solid-state process to join Nickel Titanium (NiTi) shape memory alloy. The retention of shape memory effect has enabled the welded NiTi alloy to be exploited in various functional applications. In this article, the NiTi sheets of 1.2 mm thickness are welded using FSW. The tool selection, geometry design and process parameters required to weld NiTi sheets are explored. Interestingly, an attempt is made to actuate the welded NiTi alloy, using laser actuation technique. The laser beam is scanned over the sample at a particular speed, enabling the increase in temperature suitable for physical actuation. A minimum and maximum displacement of 10 mm and 28 mm are recorded for the laser powers of 10 W and 50 W, respectively. Apart from laser actuation, the dynamic mechanical analysis of the welded NiTi alloy is investigated.

This work presents the influence of functionalised graphene nanoplatelets (f-GnPs) and functionalised glass fibers (f-fiber) on the tensile strength and the fracture toughness of the GFRP composites. The functionalization on the glass fabric and GnPs was performed by using 3-Aminopropyltriethoxysilane (APTS) as a coupling agent and confirmed by Fourier Transform Infrared (FTIR) Spectroscopy. The GnPs (non-functionalised and functionalised) with 0.1 wt% was introduced in the composites in two different ways, (1) dispersing GnPs/f-GnPs in epoxy; (2) depositing GnPs/f-GnPs on the functionalized fiber (f-fiber) surface. The mechanical properties, such as tensile strength and Mode I fracture toughness of the multi-phase composites were investigated. The longitudinal intra-laminar Mode I fracture toughness test was performed on the compact tension (CT) specimens by using the digital image correlation (DIC) technique to perform the fracture control study. The tensile fracture surface morphology of the composites was examined by Scanning Electron Microscope (SEM). The tensile strength of the composites with f-GnPs deposited on the f-Fiber outperformed the unmodified composites with 16% enhancement owing to the strong fiber/matrix interface bonding developed by f-GnPs. The composites with f-GnPs dispersed in the matrix showed an increase in the fracture toughness (KIC) of 76% over the unmodified composites. The effects of the f-GnPs dispersed in the matrix showed good interfacial adhesion, while the composites with f-GnPs deposited on the f-Fibers showed poor fiber/matrix adhesion, as observed in the tensile fractography of the composites.

Bismuth vanadate (BiVO4) and nickel ferrite (NiFe2O4) nanoceramics were successfully synthesized using hydrothermal and sol-gel methods, respectively. Three different composites between magnetic NiFe2O4 and non-magnetic BiVO4 phases (25 wt% BiVO4 + 75 wt% NiFe2O4, 50 wt% BiVO4 + 50 wt% NiFe2O4 and 75 wt% BiVO4 + 25 wt% NiFe2O4) were prepared and characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and UV–Visible spectroscopy. The PXRD analysis indicated the formation of well-defined composites between the two phases. All three composites were found to be magnetic in nature as confirmed from magnetic measurements carried out using vibrating sample magnetometer (VSM). The saturation magnetization (Ms) values found to be decreased almost linearly with increasing BiVO4 content in the composite, due to magnetic dilution induced in the composites by the non-magnetic BiVO4 phase. Band gaps of all the as-synthesized compounds were determined using diffuse reflectance spectroscopy (DRS) and are found to be in the visible region which makes them suitable for the photocatalytic dye degradation application. Among all the prepared magnetic composites, the composite with 50 wt% BiVO4 + 50 wt% NiFe2O4 exhibited the highest photocatalytic activity towards the degradation of 10 ppm methylene blue solution. Further enhancement of photocatalytic efficiency was achieved by the addition of a known volume of H2O2. Overall, 80% dye degradation efficiency was achieved using the composite of 50 wt% BiVO4 + 50 wt% NiFe2O4 under sunlight. Since the composites are magnetic in nature they can be easily separated from the heterogeneous reaction mixture using a laboratory magnet, after the photocatalytic treatment.

OBJECTIVE: In this article, monomers (tannic acid (TA) and m- phenylenediamine (MPD)) were used in the fabrication of a novel PES based thin-film composite nanofiltration (TFC-NF) membrane for the treatment of a common effluent treatment plant (CETP) of textile industrial wastewater. MEMBRANE SYNTHESIS: PES support sheets and TFC layers were fabricated via non-solvent induced phase inversion and in-situ interfacial polymerization (IP) process. The ultra-thin active layer was synthesized via the IP process with monomers such as tannic acid (TA) and m- phenylenediamine (MPD). T and M series membranes correspond to (PES/x wt% TA, x = 2, 4, 6) as T1, T2, T3 -TA and (PES/x wt% MPD, x = 2, 4, 6) as M1, M2, M3–MPD respectively. M0 corresponds to PES which is the virgin membrane. RESULTS: The chemical structure, surface morphology, surface roughness and surface properties were explored using fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and contact angle, respectively. The filtration performance of the thin-film composite nanofiltration (TFC-NF) membranes was investigated by various properties like pure water flux, salt rejection, porosity, mean pore radius and antifouling analysis. CONCLUSION: T1-TA membrane showed better water permeability, high salt rejection and better industrial effluent rejection with 94.4% of TDS that are suitable for industrial reuse and agricultural irrigation. Moreover, for T1-TA membrane, the water flux, porosity, mean pore radius, salt rejection, surface roughness and contact angle of 43.5lm(− 2)h(− 1), 47.1%, 16.7nm, 72.7%, 11.7nm and 41.48°was achieved respectively that was found to be higher than that of all the other fabricated membranes. Further, the rejection efficiency rate of textile effluent characteristics such as pH, turbidity, TDS, alkalinity, total hardness, BOD and COD were also achieved with maximum deduction in the T1-TA TFC-NF membrane compared to the M0-Virgin PES membrane. From the results, it can be confirmed that the T1-TA membrane significantly reduced the alkalinity, total hardness, BOD and COD rejections of 78%, 77.3%, 58.5% and 67.5% respectively, present in the effluent. Water flux recovery ratio (FRR) was improved from 74.6% for M0-Virgin PES membrane to 94.8% for T1-TA membrane. The modified TFC-NF membranes especially T1-TA, had better anti-fouling property and excellent hydrophilicity than the unmodified M0-Virgin PES membrane. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00624-x.

Chemical looping combustion (CLC) is a promising technology paving the way for the inherent CO2 capture. As Indian coals are enriched in ash content, their utilization in the CLC technology under direct fueled condition is challenging due to the ash layer resistance in the reactivity of metal oxides. Alternatively, the blending of biomass with high ash coal (HAC) can enhance fuel reactivity with metal oxides. In this context, the present study is focused on the co-utilization of high ash Indian coal (ash 33 wt %) and rice straw (RS) in the CLC process using Fe2O3 particles as metal oxides in a fixed bed reactor under CO2 based in-situ gasification mode of operation. The intrinsic reactivity of ash, char, and volatile matter of the solid fuels with Fe2O3 is assessed individually. The obtained CLC based experimental results showed that the CO2 capture efficiency and gas conversion are found to be increased by 9.7% and 6%, respectively, during the co-utilization of HAC and RS. The reactivity of H2, CO, and CH4 with Fe2O3 is also assessed under the co-combustion mode of the CLC process. The XRD results showed that the formation of calcium ferrite (CaFe2O4) had enhanced the conversion of char during the CLC process. A higher reactivity between char and Fe2O3 (solid-solid interaction) is observed at high operating temperatures with 13% increase in the weight loss under the co-combustion mode of the CLC process. Further, the kinetic parameters are evaluated for the CLC and non-CLC based reactions under various operating temperature regimes. Among the kinetic models considered, the shrinking core model is found to be the best fit, compared to the homogenous progression model. The chemical reaction is the slowest step at the operating temperatures in the range of 200–500 °C; ash layer diffusion is found as the rate controlling step at high operating temperatures (800–1000 °C); whereas film diffusion controlled mechanism is dominant at 700–800 °C.

The present work focuses on the laser turning of Alumina (Al2O3) ceramic materials and to analyze the effect of various machining input parameters. The design of experimental trials based on the Taguchi technique and the experimental process input values are considered such as pulse frequency, workpiece rotational speed, laser beam average power, and constant feed rate. The optimum process parametric settings are identified for the output parameters of surface roughness (Ra) and Material removal rate (MRR). The output responses are analyzed based on the signal-to-noise ratio. Based on the experimental study, the better surface roughness (Ra) is achieved as 2.37 µm for the input response combination of A1B1C1. Similarly, the Material removal rate is achieved as 0.79 mm3/min for the combination of A1B1C3.

Aluminum 7075 has proved its dominance in numerous applications because of its strength and light weight. Recent research in AA7075 has brought high potential in improving wear resistance, corrosion and machinability. This paper is highly concentrated to improve the wear resistance of AA7075 used in automotive applications. This work includes fabrication of AA7075 with predetermined compositions of SiC by using friction stir processing. First, SEM analysis has been carried out to ensure the defect free zone of surface hybrid composites. Secondly, L9 Taguchi array design was used to obtain wear behavior analysis. Based on the experimental results, influencing factor on wear rate and coefficient of friction (COF) was examined. Based on grey relational analysis (GRG) analysis, Load places a major contribution of 54.22% compare to wt. % of Sic and Sliding velocity on wear and COF and improvement in GRG is achieved by 17%.

This investigation reveals the paradigm of EDM in this experiment to expel the metal from Al7075 with a performed Copper electrode. Aluminium7075 has the most elevated quality, higher firmness, and diminished thickness. Aluminium7075 is utilized prevalently in exceedingly focused on applications, for example, brackets, milk churns, mineral skips, cranes, external tank and scaffolds. Though EDM offers simple machinability joined with an excellent surface finish. Machine parameters of foremost noteworthiness, such as current (amp), pulse off time, pulse on time (µ sec), fluid pressure (kg/cm2) and spark gap (mm) are contemplated utilizing Taguchi L18 orthogonal array. With the help of mean effective plots, tool wear rate (TWR), metal removal rate (MRR), cylindricity, circularity, and perpendicularity are examined. Information on such output levels and their impact on performance was investigated. The aftereffect of the investigation, the metal removal rate (MRR) increases when the current (10 amp) and pulse on time (29 µs) is increased. The tool wear rate (TWR) improves when the current (10 amp) and pulse on time (27 µs) is improved at the same time spark gap (0.4 mm) is reduced. And finally, the geometrical tolerance is also improved.

In the present work, NBR/PVC conventional composite containing 70phr carbon black (CB) is taken for study. In order to reduce the utilization of CB, new hybrid nanocomposites containing a fixed content of 55phr (Parts by weight per hundred of rubber) CB and varied content of COOH functionalized graphene nanoplatelets (GNP) (3phr–9phr) were developed by melt-blending on a twin roll mill and their morphology and mechanical properties were tested and compared with conventional composite. The prepared composites were examined for their morphology and various physico-mechanical properties. Studies revealed that incorporation of GNP in NBR/PVC matrix resulted in superior mechanical properties and swelling resistance in comparison to NBR/PVC composites containing CB alone. Further NBR/PVC hybrid nanocomposites containing 55phr of CB and 6phr of GNP exhibited an improvement of 7%, 42%, 29% and 20% in stress at break, modulus at 100% elongation, tear strength and resistance to swelling in comparison to the conventional composite containing 70phr CB. The same composite also exhibits superior hardness and compression The better performance of NBR/PVC hybrid nanocomposites can be mainly ascribed attributed to immense surface area of functionalized GNP and its enhanced interactions with the NBR/PVC matrix, enhanced CB-GNP interactions, improved dispersion of graphene in the NBR/PVC matrix due the existence of carboxyl (COOH) group on the surface of graphene layers and formation of more cross-links between rubber and fillers with increase in nanofiller content. FESEM studies reveal the formation of exfoliated structures of GNP and local CB-GNP hybrid filler network. These studies prove that partial replacement of CB with GNP is a promising approach to produce NBR/PVC composites with superior mechanical properties and swelling resistance.

Electrical and electronic scrap (E-waste) was hazardous to the environment as well as difficult to dispose of and recycle. The framework was developed to reuse the E-waste in the form of value-added material. In this research work, four different combinations of hemp/epoxy composite (C1, C2, C3, and C4) were fabricated with E-waste particles (3 wt%) in the size of 300µ, 425µ, and 600µ. The influence of E-waste on different composites was assessed through mechanical and machining characterization such as tensile, flexural, impact, hardness, and drilling was done as per ASTM standards. E-waste (600µ) added composite C4 specimen shows the improvement in tensile (47.8%) and impact strength (46.6%) whereas C2 specimen shows higher flexural strength (14.8%) than C1 specimen. Drilling analysis was conducted for the entire four fabricated composites and found out the spalling defect occurs while drilling for the prepared DOE. The result proves that reusing the e-waste in the form of composite material improves mechanical properties, reduces pollution, and global warming. The SEM analysis has proved the bonding between E-waste and matrix and the distribution of particles.

Li-ion batteries play a vital role in electromechanical devices. The heat load on such batteries varies with time and application which falls as high temperature rise and it causes severe damages on a device and reduces the life cycle. It will be a big challenge in future decades of electronic devices and the electric car revolution. To overcome such difficulties, this work is considered for thermal management of small Li-ion batteries to check the possibilities through the micro heat pipe. Due to the high impact of nanotechnology in heat transfer science, acetone, deionized water, and tetrahydrofuran fluids are blended with graphene oxide nanoparticles to prepare the nanofluids by ultrasonic method. Here, tetrahydrofuran is a new combination of nanoworking fluid and not addressed by pre-researchers. Tet-rahydrofuran-graphene nanofluid provides 61% of improved thermal conductivity than the other two fluids which accelerates the heat transfer rate with reduced thermal resistance in the range of 0.09-0.64?C/W. To validate the experimental results, a real-time study has been done on Li-ion batteries for a day and ensured the reduction of overheat issues. Hence, the present work will support the Li-ion battery to work in an optimal temperature range in a new way of micro heat pipe with nanofluid.

The development of cheap and efficient oxygen reduction and evolution reaction catalysts are important, which not only push the electrochemical energy systems including water electrolyzers, metal-air batteries, and fuel cells nearer to their theoretical limits but also become the substitute for the expensive noble metal catalysts (Pt/C, IrO2 or RuO2 and Pt-Ru/C). In this review, the recently reported potential graphene-based air catalysts such as graphene with non-metals, non-noble metals, metal oxides, nitrides, sulfides, carbides, and other carbon composites are identified in-light-of-their high oxygen reduction reaction/oxygen evolution reaction activity and zinc-air battery performance for the development of high energy density metal-air batteries. Further, the recent progress on the zinc-air batteries including the strategies used to improve the high cycling-performance (stable even up-to 394 cycles), capacity (even up-to 873 mAh g−1), power density (even up-to 350 mW cm−2), and energy density (even up-to 904 W h kg−1) are reviewed. The scientific and engineering knowledge acquired on zinc-air batteries provide conceivable development for practical application in near future.

This work investigated the effect of various concentrations of Eosin Y dye on the performance of the Dye-sensitized solar cell (DSSC). Distinct concentrations like 10 mg, 20 mg and 30 mg of Eosin Y Dye were prepared for the construction of DSSC. For preparation of photoanode, Titanium dioxide nanoparticles were used to prepare paste, which was deposited on fluorine doped tin oxide (FTO) glass substrate by Doctor blade technique. Absorption spectra of the dyes were taken, and the photovoltaic performance was measured for the fabricated cells. The highest efficiency is obtained by the cell with 10 mg of Eosin Y which is 0.39%. The conversion efficiency of the cells with 20 mg and 30 mg of Eosin Y are 0.007% and 0.0015% respectively.

In this work the effect of halloysite nanotubes (HNT) on the mechanical properties and thermo-oxidative ageing behaviour of Nitrile-Polyvinyl chloride rubber (NBR/PVC) nano-composites is investigated. NBR/PVC nano-composites containing 2, 4, and 6 phr of HNT were prepared by melt-blending on a twin roll mill. X-ray diffraction and Field emission scanning electron microscopy studies revealed formation of limited intercalated structures in NBR/PVC matrix. Fourier transform infrared spectroscopy studies confirmed the formation of hydrogen bonding between NBR/PVC and HNT. Improved interaction between NBR/PVC and HNT increased the tensile strength, elongation at break and tensile modulus by 34%, 22%, and 23% respectively and improved the hardness and compression set. Hot air ageing tests revealed that all the NBR/PVC nano composites demonstrated excellent retention of properties compared with that of conventional composites.

In the present work, the investigation of mechanical properties and specific wear rate of Al 6061 reinforced with silicon carbide (SiC) with different wt. % is carried out. The stir casting method was used for the fabrication of metal matrix composite and the SiC particle size of 25 µm was reinforced with two (C1-2.5% SiC C2-5% SiC) different weight percentages in Al6061. The SiC particles were preheated at 450 °C for 15 min and mixed with matrix at 850 °C. The mechanical properties such as tensile test, hardness, and dry sliding wear were conducted and the test specimen was prepared as per ASTM standard. The hardness value of 84 BHN was obtained for the C2 composite than the C1 composite (76 BHN). The tensile strength of the C1 composite was obtained in the order of 157 Mpa compare to the C2 composite (77 MPa). The C2 composite has shown a higher wear resistance than the C1 composite. The microstructure image of the composites was taken for ensuring the distribution of the reinforcement through SEM. The test results ensured that the reinforcement has a strong impact on the base materials, by using SiC in Al6061 can be tailored for a specific wear application.

This paper discusses with the synthesis of nanoparticles of ZnO and ZnO-SiO2 nanocomposite by sol–gel method. Characterisation studies are taken for each sample and compared with previous literatures. Therefore, the synthesized particles were characterized by FTIR, SEM, XRD & BET analysis to obtain chemical bonding, surface morphology, crystallinity and surface area of the particles respectively micrographs of ZnO nanoparticles show hexagonal shaped ZnO and ZnO-SiO2 nanocomposite revealed an increase in particle agglomeration. In order to understand the crystallite size of ZnO and ZnO-SiO2 nanocomposite were found to be 44.37 nm and 34.09 nm respectively. Practically, both synthesized ZnO and ZnO-SiO2 nanocomposite applied for the preparation of biodiesel applications. Biodiesel is an alternative to petroleum-based diesel that is biodegradable, non-toxic and being less polluting. Based on the literatures, they produced biodiesel from waste cooking oil using transesterification process with ZnO and ZnO-SiO2 nanocomposite as heterogeneous catalysts. The fame conversion was confirmed by FTIR and GCMS analysis. The prepared biodiesel was characterized by its physical and fuel properties like density, kinematic viscosity, flashpoint and calorific value.

Biofuel is renewable, environmentally friendly and non-toxic in nature. The present work focuses on the preparation of biofuel from waste cooking mustard oil. Biofuel was synthesized from waste cooking mustard oil using CuO nanoparticles as a heterogeneous catalyst for converting waste cooking mustard oil into biofuel in the presence of methanol. XRD peaks confirm that the formation of CuO from each precursor was in a monoclinic phase and the average grain size of CuO crystallite was found to be 13 nm. The FTIR results confirmed the presence of methyl and ester groups in the synthesised biofuel. FESEM images indicate the morphology as facets broken flower. The EDAX result shows that there are no other elemental impurities present in the prepared CuO nanoparticles. The product was analysed by GC–MS to verify the Fatty Acid Methyl Esters (FAMEs). Transesterification was used to reduce the viscosity of the oil. These results reveal that the synthesized biofuel can be considered as a prospective alternative fuel over the conventional diesel fuel.

Well structured nano-sized Copper oxide has been prepared by simple reflex method for different pH concentrations. The Prepared samples are subjected to various characterization studies such as XRD, SEM, UV–Vis spectroscopy and FTIR spectroscopy inorder to investigate their crystallite structure, morphology, optical properties and functional vibrations. The structural analysis of prepared CuO samples revealed a monoclinic crystalline structure. The morphology of CuO samples reveals spindle shaped with size distribution ranging from 70 nm to 90 nm. The sample prepared at pH 5 seemed to possess the expected qualities to apply for antibacterial activity. The prepared samples consisting of various amounts of CuO nanoparticles are developed to study the antibacterial activity for different strains of bacteria. The results showed that at the optimized pH concentration, CuO samples calcinated at 400 °C exhibited improved antibacterial activity for E. coli bacteria.

Though many reports are available on polymer based piezoelectric sensor devices since the last decade, the novelty of the present work is to study the piezoelectric sensor characteristics of electrospun (a). Neat poly(vinylidene fluoride) (PVDF) and (b). PVDF/aliphatic hyperbranched polyester of 3rd generation (HBP-G3) blend (80/20 w/w) for energy-harvesting applications. Our work is segregated into two parts: In the first part, we synthesized aliphatic HBP-G3 using pentaerythritol (as core), dimethylol propionic acid (as monomer) and p-toluene sulphonic acid (as catalyst) using one-shot melt-polycondensation method, and characterized the final product using spectral and thermal measurements. Further, neat PVDF and PVDF/HBP (80/20 w/w) blend solutions were prepared by mixing with selected solvents and their electrospinning were carried out under controlled conditions. Upon characterizing the nanoweb samples using FTIR and XRD techniques, the blend nanoweb was confirmed to exhibit higher β-crystallinity than that exhibited by neat PVDF nanoweb. This serves as an evidence that it is possible to fabricate a piezoelectric sensor with higher output voltage using PVDF/HBP blend than that achieved using neat PVDF. Finally, dynamic-pressure measurements were carrried out to measure the peak-to-peak output voltage (Vp-p) data, which revealed higher Vp-p (+6.21 V) for blend sample compared to neat PVDF (Vp-p = +0.95 V).

A heat pipe is a two-phase device with a very high effective thermal conductivity and heat transfer rate. It consists of a phase change material, wick structure and an envelope. Usually, the heat pipes are circular in shape. In this paper, we analyze different shapes of the heat pipe and how it affects the performance of the pipe without changing its internal volume and central thickness. Flow property of the phase change material changes with geometry. The fluid velocity is minimum at the pipe surface and maximum at the pipe centre because of the no-slip condition. We have selected one circular and two flat geometries with a different number of edges. The advantage of flat geometry is an increased surface area of contact. ANSYS simulation software is used to simulate the working of the heat pipe. Several performance parameters including pressure, velocity, temperature and effective thermal conductivity were calculated and compared. The effect of an increase in the number of edges on different performance aspects of the heat pipe is studied. From the results of simulation software, it is observed that the change in geometry affects the thermal properties significantly.

Extended Surfaces widely known as “Fins” are the surfaces that are extended from the actual body or system to enhance the heat transfer rate. Generally, the heat transfer from the body dissipates either to the environment or from the environment by increasing the surface area for the convection heat transfer to take place. In this present research work, CAD model of a segment of condenser tube of air conditioner is taken to perform thermal analysis and simulation on the application of constant internal applied temperature. Alongside the change in the materials of the extended surface as well as the tubing of the condenser is also analyzed. The experiment results shows five different iterations based on the change in material of the corresponding thermal body of extended surface and the condenser tube of the air conditioner. The paper majorly focuses on the temperature, heat flux and thermal gradient of the condenser tube segment. From the results of simulation software it is observed that the change in material has made significant effects on the thermal gradient of the condenser tube and concluded that the high strength aluminum fin and copper tube combination is more distinct compared to other material combinations.

The combination of nickel and chromium has provides better substance properties. In addition to that, the Silicon Carbide (SiC) particulates (weight percentage of 1.50) were mixed to the base alloys to enhance the further substance properties. The tensile strength and density of the composite was increased. The chemical composition was validated through Energy Dispersive Spectroscopy (EDS) test. The chrome composite was drilled by ultrasonic vibrations. The voltage, slurry concentration and abrasive grit size was chosen for control factors. The Material Removal Rate (MRR) was determined through the combinations of control factors. Taguchi approach was used to optimize the ultrasonic machining factors. The factors effects have been discussed through variance test and Pareto chart.