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In this work, the popular metal oxide; Copper oxide (CuO) were prepared by well-known method; sol gel technique. The structural and morphological examination was carried out on the fabricated metal oxide and the XRD evaluation results validated the strong amalgamation of monoclinic bravais lattice system. The nano level of the Cu particles was tested and the size determined to be 52–36 nm which was found to be varied with respect to annealing temperatures. The structural modification of nanoparticle ensemble crystal by the application of temperatures was studied. The Photocatalytic ability was tested and it was evaluated by applying Tri-(chloroisopropyl) phosphate with CuO material. The optical property inducement was recognized in the material by observing UV–Visible characteristics curves. The electric operated optical response between lower and higher wavelength zones in visible region was tested by hyper polarization.

The increase in demand and introduction of stringent emission regulations resulted in the need to develop and implement innovative technologies towards improving the emission and performance characteristics of compression ignition engines. A hybrid metal matrix composite piston (HMMC) of Al7075 reinforced with 6% of 100 μm Silicon Carbide (SiC) and 4% of 100 μm Aluminium oxide (Al2O3) was fabricated. The HMMC piston was mounted on a compression ignition (CI) four stroke single-cylinder constant speed engine and the test was carried out with eddy current dynamometer attached with computerized data acquisition system. This paper is focused on the study of performance of Al7075-SiC-Alumina composite piston for compression ignition engine application. Experimental investigations were performed at injection pressure of 200 and 220 bar on both standard piston and HMMC piston and analysed the performance, combustion and emission behaviour of CI engine. From the results it was found that the HMMC piston exhibits an improved efficiency and thereby improving the lifetime of the engine. Though a little compromise in performance and emissions has been accepted, the implementation of HMMC pistons will reduce the carbon foot print of running an internal combustion engine.

Self-Compacting Concrete (SCC) is an emerging building material as it has unique benefits over conventional concrete. SCC is a High-Performance Concrete (HPC) having the filling ability, passing ability and segregation resistance. In addition, SCC does not require vibration. However, to develop SCC, an appropriate mix design has to be carried out following EFNARC guidelines. This paper attempts to develop a design mix proportion for grades of SCC such as M25, M30, M35, and M40. The requirements of fresh SCC are validated with appropriate experiments such as the V-funnel test, J-ring test, and slump flow test. Cube compressive strength of different grades of hardened SCC was validated at 28 and 56 days. The other mechanical properties, such as tensile strength, flexural strength, and modulus of elasticity, were also examined for different grades of SCC, and the test results are reported. Fire-resistance of building materials has to be assessed to ensure the fire safety of humans and infrastructure during the event of fire accidents. Stress–strain curves were developed to characterize the behaviour of different grades of SCC under elevated temperatures. Three stages of elevated temperatures, such as 300, 600, and 900 °C with two methods of heating, were considered in this experimental investigation. It was observed that the maximum stress capacity of SCC linearly decreases with respect to the elevated temperature. Also, the peak strain of different grades of SCC increased as the exposure temperature increases. The changes in the ductile property of different grades of SCC are found to be quantitatively evaluated in terms of Energy Absorption Capacity (EAC). The EAC values are found to be decreased when the exposure temperature increases.

Recent developments in the infrastructure urged the requirement of developing concrete with high performance. This research work presents the development of sustainable High Strength Fiber Reinforced Concrete (HSFRC), and its mechanical properties such as compressive strength, tensile strength and flexural strength compared to conventional High Strength Concrete (HSC). Ordinary Portland Cement (OPC) was replaced with optimum amount of Micro-Silica (MS) and Pumice Powder (PP) by 15% and 10%. Hybrid Fibers (HF) are added in the mix of 1.5% by volume of concrete. The fibers used are Steel Fiber (SF), Poly-Propylene Fiber (PPF), Basalt Fiber (BF) and Carbon Fiber (CF). Effect of fiber and its performance are compared with conventional HSC. A concrete mix with optimum content of ingredients is desired to satisfy the strength and workability. Compressive strength of mix with HF combination of SF and PPF is found to be higher than other mixes. Mix with SF and BF exhibited higher tensile strength. Contribution of fibers was confirmed by SEM analysis.

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.

As per Code of Indian Standards, a concrete having a compressive strength greater than or equal to 65 N/mm2 is referred to as a high strength concrete. High strength concrete has many favorable properties, but it is a brittle material and has a low rate of increase of tensile strength due to which it is not of great use in earthquake-prone areas. The best method to improve the flexural shear behavior is to incorporate fibers in concrete at the required proportions. This paper investigates the flexural shear behavior of high strength concrete beams by replacing traditional shear reinforcements with steel fibers only in the shear span. The effect of varying volume fractions of fibers (0%, 0.5%, and 0.75%) is also studied. It was found that the brittle failure was converted to ductile failure by fiber addition only in shear span. The load carrying capacity, compressive strength and split tensile of high strength concrete increased with increase in fiber volume.

Study of doped nanoparticles attracts more attention by many researchers due to its significant properties. In the present work different percentage of cadmium (Cd) doped copper oxide (CuO) nanoparticles were prepared using cost effective and simple Sol gel method. The structure, optical, morphology and I-V (current–voltage) properties of the synthesized nanoparticles were investigated. X-ray diffraction (XRD) studies of the synthesized sample reveal the monoclinic structure of CuO nanoparticles. UV–vis spectroscopy revealed that after doping, the absorption increased and the band gap energy decreased in the range 3.85–3.80 eV. The FTIR spectra show the presence of chemical bonding and functional groups at the CuO nanoparticles interface. I-V characterization revealed that the maximum conductivity value of the Cd (3%) doped CuO nanoparticles was 7.4x10-9 S/cm. Using J-V, the diode parameters of different weight percentage of the Cd doped CuO nano particles were measured in dark and under illumination. In the dark, the ideality factor (n) and barrier height () of Cd (3%) doped CuO nanoparticles are 17.52 and 0.90 eV, respectively and in the light, they are 8.6 and 0.92 eV.

Organic semiconducting polymers exhibited promising photocatalytic behavior for hydrogen (H2) evolution, especially when prepared in the form of polymer dots (Pdots). However, the Pdot structures were formed using common nonconjugated amphiphilic polymers, which have a negative effect on charge transfer between photocatalysts and reactants and are unable to participate in the photocatalytic reaction. This study presents a new strategy for constructing binary Pdot photocatalysts by replacing the nonconjugated amphiphilic polymer typically employed in the preparation of polymer nanoparticles (Pdots) with a low-molecular-weight conjugated polyelectrolyte. The as-prepared polyelectrolyte/hydrophobic polymer-based binary Pdots truly enhance the electron transfer between the Pt cocatalyst and the polymer photocatalyst with good water dispersibility. Moreover, unlike the nonconjugated amphiphilic polymer, the photophysics and mechanism of this photocatalytic system through time-correlated single-photon counting (TCSPC) and transient absorption (TA) measurements confirmed the Forster resonance energy transfer (FRET) between the polyelectrolyte as a donor and the hydrophobic polymer as an acceptor. As a result, the designated binary Pdot photocatalysts significantly enhanced the hydrogen evolution rate (HER) of 43 900 μmol g-1 h-1 (63.5 μmol h-1, at 420 nm) for PTTPA/PFTBTA Pdots under visible-light irradiation.

The authors report the preparation of the nanocomposite comprising of vanadium pentoxide (V2O5) and selenium (Se) nanoparticles and functionalized multiwalled carbon nanotubes (MWCNTs) (V2O5@Se NPs/MWCNTs). Since Se NPs possesses extraordinary physicochemical properties including larger surface area with higher adsorption capacity, V2O5 NPs were adsorbed onto Se NPs surface through physisorption process (designated as V2O5@Se NPs). The nanocomposite synthesized hydrothermally was evaluated for its antimicrobial activity. The morphology and microstructure of the nanocomposite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively. Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis) were employed to analyze the spectral properties of nanocomposite. The microbicidal efficacy of nanocomposite was tested against Gram-negative (G-)ZGram-positive (G+) bacteria and fungus. This is the first report on the synthesis of V2O5@Se NPs/MWCNTs nanocomposites by chemical method that showed microbicidal effect on micro-organisms. The thiol (-SH) units facilitates the enrichment of V2O5@Se NPs onto MWCNTs surface. Ultimately, it reflects on the significant antimicrobial activity of V2O5@Se NPs/MWCNTs.

Monel K-500 is a Nickel based super alloy which have superlative properties such as high strength, resistance to corrosion, retention of mechanical properties at service temperature and structural stability. It finds wide application in aerospace application, nuclear reactor, gas turbines, submarines, combustion engine exhaust valve, petro chemical components, heat exchanger, etc. However, during machining of super alloys, difficulties are there due to its low thermal conductivity and work hardening effect. Challenges in conventional machining can be minimized by using suitable machining as well as process parameters. Among the different machining processes, not much work has been initiated on drilling of above super alloys. Normally, drilled holes are used in screws, bolts, shafts, steam pipes, fitting of furniture and other equipments. By considering the applications and difficulties in machining of super alloys, drilling experiment is selected on Monel K-500. Experiments were conducted as per Taguchi’s L9 orthogonal array using process parameters such as different drill tool material, drilling speed, feed and cutting fluids and Surface roughness and MRR values were measured as output responses. Effect of selected process parameters on the above machinability responses were analyzed. Optimum process parameters were identified to improve the machinability of Monel K-500.

At present, industries require tremendous new technologies to solve the challenges faced in the production process. In the existing researches, Al7075 is frequently used but Al7050 is rare hence, in this study the effort has been made on the development of Al7050 and Al7075 alloys reinforced with Granite and Silicon carbide particles using stir casting technique. The nine different reinforcing mix ratios are fixed by using the Taguchi method performed in Minitab. Morphology of the reinforced particle is examined under optical microscopy and the mechanical properties such as hardness, impact, and wear of both Al7050 and Al7075 composites are studied. The Brinell hardness test is carried out to assess the hardness of both composites. Besides, Hybrid Deep Neural Network-based Salp Swarm Optimization (DNN-SSO) is performed to forecast and validate the experimented mechanical properties and compared with related neural networks. In which, the proposed DNN-SSO shows better outcomes by providing closer results to the experimented characteristics than the predicted DNN and ANN. From the overall study, in both Al7050 and Al7075 composites, hardness and wear rates are optimal when using 12% of granite and 6% of SiC particles. The optimal impact strength is achieved from 8% of granite and 4% of SiC particles. Besides, the reinforced composite of Al7050 possesses favorable impact energy and Al7075 possesses better hardness and wear rate. The superior mechanical characteristics observed for hardness is 141.22 BHN, wear rate is 0.00125 mm3/m and impact energy is 13.35 J. The predicted characteristics obtained using the proposed hybrid DNN-SSO achieve closer values to the experimented outcomes.

The use of aluminum alloys has become far greater than ever with increasing needs for lighter and stronger structures leading to new aluminum alloys with rare earth admixtures. Scandium (Sc) is one...

Solutions to nonlinear free vibration analysis of an arbitrarily laminated thin rectangular plate subjected to thermo-piezoelectric load is investigated. The governing equation of motion is based on von Karman’s deflection of thin plates to capture the effects of moderate geometric nonlinearity. Induced strain actuation assumption is confined to a linear model for applied low electric fields and varying temperature distribution along the thickness direction. The solution for lateral displacement field for simply supported and clamped condition edges are determined by displacement-stress; mixed formulation. The applied Galerkin’s projection reduces the governing nonlinear partial differential equation to a time dependent ordinary differential equation. Solutions are obtained using a predictor-corrector numerical integration scheme. The effects of randomly applied actuation potential and thermal loading on nonlinear frequency ratio are examined. The marginal values provided using various probabilistic methods are found to be in good agreement with each other.

The complexity in the shear behaviour of reinforced concrete (RC) beams increases with a decrease in the shear span to effective depth ratio (av/d) because of the increase in the contribution of concrete to the shear resistance of beams. Various models (e.g. numerical models and strut and tie models) for estimating the shear capacity of non-slender RC beams are proposed in the literature, with each having advantages and limitations. In this work, two simpler mechanics-based shear capacity models were considered, one for beams with 1 ≤ av/d v/d v/d range. Knowing the probability density function of the shear capacity and the mean and standard deviation of the shear capacity obtained using a first-order approximation, a characteristic shear capacity equation (Equation 5) is proposed for the design of beams with 1 ≤ av/d v/d

An automotive bumper system consists of an energy absorber, fascia and bumper beam. Among them, the bumper beam is the main component contributing to the overall weight of the vehicle. The bumper beam absorbs the kinetic energy during an accidental collision by deflection in low speed impact and by deformation in high speed impact. Carbon Fibre Reinforced Plastic (CFRP), being an extremely strong and lightweight composite, is a good candidate for bumper beam material. Earlier used in high performance cars CFRP is nowadays being promoted to be used in passenger cars also. The reinforcement beam is the vital part which ensures safety and needs to be validated through Finite Element Analysis (FEA). Therefore, the double hat bumper beam is impacted with a cylindrical impactor and analyzed in Abaqus. In this paper the bumper beam is analyzed after weight reduction by putting circular holes for material saving. Further the effect on cost of production is calculated. Above all, material saving reduces carbon footprint.

The present work investigates the effects of selected welding process parameters on the output responses for the tungsten inert gas welding of two aluminum alloys: 5083-H111 and 5754-H111. The tung...

Development of efficient solid catalysts for catalytic conversion of dilute CO2 is of extreme importance for carbon capture and utilization. We report the synthesis of bifunctional polymers co-incorporated with porphyrin-Zn as Lewis acid sites and Br- as nucleophiles for the cycloaddition of dilute CO2 with epoxides in this work. It was found that the Br-/Zn ratio has a volcano relation with the activity of bifunctional polymers in a cycloaddition reaction, indicating the synergy effect between Lewis acid sites and nucleophiles. The turnover frequency (TOF) of the bifunctional polymer is more than four-fold that of the physical mixture of tetrabutylammonium bromide and porphyrin-Zn-incorporated polymer, implying the enhanced cooperation between Br- and porphyrin-Zn in the polymer network. The bifunctional polymer with optimized Br-/Zn afforded 99% conversion, 99% selectivity, and a TOF as high as 12,000 h-1 for the cycloaddition of CO2 and propylene oxide, which is among the most active solid catalysts ever reported. Furthermore, the bifunctional polymer could efficiently catalyze the cycloaddition of epichlorohydrin with dilute CO2 (7.5% CO2 balanced by N2) even under ambient conditions, demonstrating its potential application in industrial-scale production.

In this present study, two dissimilar aluminum alloys of AA5052-H32 and AA6061-T6 were joined in butt joint configuration to examine the influence of process parameter on tensile strength and microstructural examination. Tool profiles such as square, cylinder, triangle with welding speeds like 30, 60, 80 mm/min and tool rotational speeds such as 800, 950, 1100 rpm were selected as process parameters for friction stir welding. Among the various tool profiles, square pin profile produced good pulsating action of 60 pulses and having max SV/DV ratio of 2.3 which helped to produce higher tensile strength. Microstructural examination on the nugget zone revealed that higher welding speed causes some cracks in the nugget zone due to insufficient stirring of the materials. Microhardness examination reveals that HAZ of both zones exhibited lower hardness on both sides. Nugget zone at centre was measured with increased hardness than BM of AA5052 and lower than AA6061. SEM fractography revealed that the specimens were failed in ductile mode and specimens failed at higher tensile strength observed with high ductility. Taguchi optimization technique has been implemented and the process parameters combination was optimized for higher tensile strength. The dissimilar joints fabricated at optimized process parameters produced maximum tensile strength of 181 MPa are as follows: Tool Profile—Square, Tool-Rotational Speed—1100 rpm and Welding speed—60 mm/min.

In the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDAX) and N2 adsorption–desorption isotherm (BET). XRD and FT-IR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30 ℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption–desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.

Vibration isolation techniques with the use of quasi-zero Stiffness characteristics are a trending and impressive approach to attenuate undesirable vibration. The use of helical coil spring in quasi-zero stiffness vibration isolator with fluidic actuators (QZSFAs) plays a vital role to diminishing vibrational frequencies with less amplitude and adopting the system to various static loading conditions by adjustable damping factors. Equipping the helical coil spring in the QZSFA system is a novel scheme to suspense both excitations, although an active frequency range stands with limited reduction in amplitude owing to its axial deflection. It can be enhanced by transferring axial deflection into transverse by employing a slab, which has a significant damping character and high strength as cross-buckled type in between where the applied and excitation frequencies clash, such a novel slab is studied, developed to match the acquired performance by basalt fiber-reinforced polymer matrix composite containing graphene nanopellets (BFPMC-GnPs), and equipped with this present study to response both applied and excitation forces with less amplitude. This research work is concerned with theoretical analysis and experimental investigations of the QZSFA with the proposed composite material (QZSFA-CM). The concatenation of experimental study results that the reduced vibrational amplitude and force transmissibility of the developed system are much shorter than the existing models and provide the stability to perform under extensive frequency limits.

A series of new functional pyridine-appended pyrene derivatives, viz., 2,6-diphenyl-4-(pyren-1-yl)pyridine (Py-03), 2,6-bis(4-methoxyphenyl)-4-(pyren-1-yl)pyridine (Py-MeO), 4-(pyren-1-yl)-2,6-di-p-tolylpyridine (Py-Me), and 2,6-bis(4-bromophenyl)-4-(pyren-1-yl)pyridine (Py-Br) were designed, developed, and studied as the hole-transporting materials (HTMs) for organic light-emitting diode (OLED) application. The crystal structures of two molecules revealed to have a large dihedral angle between the pyrene and pyridine units, indicating poor π-electronic communication between them due to ineffective orbital overlap across the pyrene–pyridine systems as the two p-orbitals of pivotal atoms are twisted at 66.80° and 68.75° angles to each other in Py-03 and Py-Me, respectively. The influence of variedly functionalized pyridine units on the electro-optical properties and device performance of the present integrated system for OLED application was investigated. All of the materials have suitable HOMO values (5.6 eV) for hole injection by closely matching the HOMOs of indium tin oxide (ITO) and the light-emitting layer. All of the synthesized molecules have suitable triplet energies, glass transition temperatures, and melting temperatures, which are highly desirable for good HTMs. The pyrene–pyridine-based devices demonstrated stable performance with low-efficiency roll-off. The device with Py-Br as HTM showed a maximum luminance of 17300 cd/m2 with a maximum current efficiency of 22.4 cd/A and an EQE of 9% at 3500 cd/m2 with 7% roll-off from 1000 to 10 000 cd/m2. Also, the devices with Py-Me and Py-03 showed performance roll-up while moving from 1000 to 10 000 cd/m2.

In the present work, we modified ZSM-5 zeolite using a bio polymer poly (diallyl dimethyl ammonium chloride) and employed it for the removal of cationic dye, methylene blue from aqueous solution. The chemical and physical properties of the modified ZSM-5 zeolite were investigated using XRD, FTIR, SEM, TEM, nitrogen adsorption, TGA and 27Al NMR. Modified ZSM-5 zeolite possesses high surface area and pore diameter which was confirmed from SEM, TEM and nitrogen adsorption analysis. Adsorption of methylene blue on zeolite was investigated by batch adsorption technique. The effect of different parameters such as zeolite dosage, initial methylene blue concentration, temperature, pH and contact time on the adsorption process was discussed. Maximum adsorption capacity (4.31 mg/g) was achieved using 0.1 g of modified ZSM-5 zeolite at the optimum conditions (initial dye concentration: 10 mg/L, pH 10, temperature: 30 °C and contact time: 300 min). The experimental data were fitted into Langmuir and Freundlich models and the results indicate that the adsorption process followed Freundlich isotherm. Kinetic data were investigated using pseudo-first-order and pseudo-second-order models. Kinetic analysis indicates that pseudo-second-order model is more suitable to describe adsorption of MB on modified ZSM-5 zeolite. The reusability test suggests that the adsorbent could be reused at least six times without significant loss in removal efficiency.

During draining of liquid propellants from propellant tanks of spacecraft rocket engines, air core vortex can be formed and this can result in blockage of drain port. Supply of required amount of f...

Low-concentration hydrogen (H2) gas detection is of paramount importance in space applications as well as in medical applications. It is also critically important for safe handling of hydrogen belo...

Solid electrolyte interphase (SEI) formation in Li-ion batteries is essential for good long-term performance of the cell. However, for electrodes exhibiting high volume expansion (like Si and Sn), ...

In this work, we examined ZSM-5 zeolite loaded polyvinyl alcohol-carboxymethyl cellulose-sodium alginate (PVA/CMC/SA) membrane for cationic dye (malachite green, MG) removal from aqueous environment. The crystallinity, chemical composition, surface morphology, hydrophilicity and thermal property of PVA/CMC/SA/ZSM-5 membrane was evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), optical microscopy (OM), contact angle and thermogravimetric analysis (TGA) respectively. The successful incorporation of zeolite into PVA/CMC/SA membrane was confirmed by XRD, FT IR and SEM. TGA and contact angle measurement indicates that zeolite loaded PVA/CMC/SA membrane showed superior thermal stability and hydrophobicity than plain PVA/CMC/SA membrane. A series of adsorption studies was conducted to evaluate the influence of operational parameters such as initial dye concentration, zeolite dosage, contact time, temperature and pH on the dye (MG) adsorption behaviour of the prepared membrane. A maximum dye removal percentage (99.12%) was achieved at an initial dye concentration of 10 ppm, zeolite dosage-5 wt%, pH = 10 and temperature-25 °C. The kinetic studies revealed that adsorption of MG on PVA/CMC/SA/ZSM-5 membrane follows pseudo-second-order model while Freundlich isotherm model was founded to be the best isotherm model to describe the adsorption process. The results thus indicate a multilayer adsorption of MG on PVA/CMC/SA/ZSM-5 membrane. Finally, the recyclability test revealed that the membrane exhibits good recycle efficiency and is stable after 5 recycle.

The design and realization of a wideband substrate-integrated waveguide (SIW) cavity-backed slot antenna operating at 2.45 GHz for WLAN applications are presented. Dual dumbbell-shaped slots with rectangular slots are used to achieve increased bandwidth. The bandwidth observed is 160 MHz with the dumbbell-shaped slots. Further, it has been improved up to 9.2% by adding a rectangular slot. The wideband antenna is analyzed using ANSYS HFSS and fabricated on FR-4 substrate. The measured results of the proposed design are in good agreement with the simulation results and comparable with the reported results.

BiFeO3 (BFO), a multiferroic perovskite in nano form, is used as a photoanode for dye sensitized solar cell along with an electron transporting layer/phosphor, which is rarely reported in literature. Here Al and Cu doped ZnO (AZO & CZO) nanoparticles are composited with bismuth ferrite as this can reduce the density of electron traps and increase the conductivity of the electron transport layer (ETL) of PSCs. The power conversion efficiency (PCE) here is 0.13% but still there are other methods to enhance the PCE, as AZO, CZO is a phosphor as well as an ETL.

Friction stir welding is a promising solid state metal joining technique. It can be used to join AA2024-T3 metal plates which cannot be welded using normal fusion welding. Post weld joint efficiency depends completely on the proper selection of process variables as the required heat input for this process is not supplied by an external source but an internal function of the variables. Apart from the process variables tool pin shape also plays a vital role on the delivery of better weld strength. A comparative experimental analysis was done to understand the improvement in the post weld properties on the usage of non-cylindrical tool pin. In order to optimise major process variable for cylindrical as well as non-cylindrical tool pin geometries thermal study had been carried out and optimum heat input conditions were analysed for AA2024-T3 plates. Comparative analyses on friction stir weld joints were made qualitatively and quantitatively to understand the improvement on the introduction of noncylindrical flat faced pin in the tool.

Reinforced concrete beam is a widely used composite material for structural element. The aim of the project is to study the flexural behavior of Reinforced concrete beam with replacement of vermiculite material. The percentage of replacement of vermiculite replacement for fine aggregate is decided based on the test results of compression and split tensile strength. The replacement is done in two proportions 5 %, 10 % for fine aggregate. From this compression strength test and split tensile strength test values. I conclude that 5 % of vermiculite is the optimum percentage that be replaced with fine aggregate. Then singly reinforced beam and doubly reinforced beam are casted with and without replacement of vermiculite and tested. The comparison of the conventional beam and 5% of vermiculite replaced beam has been done and concluded that it is possible to use reinforced concrete beam with 5% replacement of vermiculite. Experimental results indicate that the two-point loading on reinforced concrete beam with 5% replacement of vermiculite for fine aggregate gives high strength then the conventional reinforced concrete beam and self-weight of reinforced concrete beam can also be reduced considerably up to 10% then the conventional reinforced concrete beam.

This work focuses on the preparation of CdSe nanostructures as they have attracted more interest in recent years due to their size and morphology dependent properties. CdSe nanoparticles have been prepared through solvothermal method using Cadmium nitrate and sodium biselenite as precursors and ethylenediamine as solvent. The effect of reaction time on the properties of CdSe especially on the morphology and size have been investigated and reported. With increase in the reaction time, the sizes of the particles are found to increase considerably. The XRD pattern also confirms the improvement in the crystallinity of the prepared samples with increase in reaction temperature. The TEM results show the formation of nanorods like structures in the sample prepared at higher temperature for longer hours.

The emergence of green biomolecules in the field of nanomaterial (NM) synthesis effectively supports the development of various size- and shape-controlled NMs for numerous applications. Accordingly, deoxyribonucleic acid (DNA) is a polymeric biomolecule that can act as a stabilizer for the fabrication of NMs due to its unique self-assembling quality. However, the use of DNA-based NMs for electrocatalytic water splitting has not been explored much although it can reduce the metal loading significantly, by as much as 20 times the commercial loading (0.205 mg cm−2). In this work, we developed palladium nano-spheres (Pd NSs) loaded on DNA as an alternative for the state-of-catalyst Pt for the electrocatalytic hydrogen evolution reaction (HER) in acidic condition. Here, the DNA plays multiple roles including stabilizing Pd NSs in aqueous medium, as a structure-directing agent and binder in electrochemical studies, avoiding the use of external binders. In the electrochemical studies, Pd/DNA (0.06 M) showed excellent activity and low resistivity towards HER in 0.5 M H2SO4. To reach a current density of 10 mA cm−2, it required the overpotential of just 79 mV with good kinetics observed with its low Tafel value of 31 mV dec−1 (0.06 M). Also, the stability of Pd/DNA was verified in a chronoamperometric study carried out for 12 h, which results no loss in intrinsic activity of the catalyst. In the electrochemical impedance spectroscopic (EIS) analysis, Pd/DNA (0.06 M) showed very low resistivity of 1.7 Ω. Additionally, the turnover frequency (TOF) was calculated at 200 mV to be 0.055 s−1 and the high mass activity of 4814 A g−1 was observed at the overpotential of 150 mV for Pd/DNA (0.06 M) with the ultralow loading of 0.01 mg cm−2. Hence, DNA-based NMs can be developed as efficient electrocatalysts towards H2 fuel production technology in the near future.

Chitosan is a biodegradable and nontoxic polymer and it exhibits piezoelectricity, which is a useful property for an electrolyte where the phototronic effect can be activated to enhance the power conversion efficiency (PCE) in solar cells. This is used here as an electrolyte in ZnO/ZnS based dye-sensitized solar cells (DSSCs). Also, to reduce the recombination of electrons, enhanced ionic conductivity and the stability of the redox this electrolyte is used. Here, ZnO/ZnS nanocomposite photo-anode is used in the fabrication of DSSCs and tested with LED lamp for the chitosan-based polymer electrolyte. The maximum PCE of 1.6% is achieved.

Magnesium alloys measure up to date category of decomposable biomaterials with identical stiffness to the bone, diminishing the harmful repercussions of stress shielding. However, Mg alloys measure troublesome to 3D printing because of the zenith chemical responsiveness that leads to a combustion risk. Moreover, Mg customary biocompatible alloying parts and low vaporization temperature will increase the problem of print absolute thick structures that balance corrosion and strength necessities. However, wire arc additive manufacturing (WAAM) has proved its proficiency in attaining the production of middling-to-enormous-scale parts. Because of the practicability of economically manufacturing enormous-scale metal parts with comparatively giant deposition rates, important advancement was created within the WAAM method's understanding, similarly because of the mechanical properties and microstructure of the imaginary parts. As WAAM has enlarged, a large variety of materials became related to the method and its applications. This text discusses the rising analysis of WAAM procedures and a summary of fabric properties. Common defects made in WAAM parts exploitation completely different alloys square measure delineate, together with deformation, porosity, and cracking. This paper concludes that the broad applications, techniques of WAAM and gives out several challenges and future scope.

Multiplexed detection and quantification of structurally similar drug molecules, methylxanthine MeX, incl. theobromine TBR, theophylline TPH and caffeine CAF, have been demonstrated via solution-based surface-enhanced Raman spectroscopy (SERS), achieving highly reproducible SERS signals with detection limits down to ∼50 nM for TBR and TPH, and ∼1 μM for CAF. Our SERS substrates are formed by aqueous self-assembly of gold nanoparticles (Au NPs) and supramolecular host molecules, cucurbit[n]urils (CBn, n = 7, 8). We demonstrate that the binding constants can be significantly increased using a host–guest size matching approach, which enables effective enrichment of analyte molecules in close proximity to the plasmonic hotspots. The dynamic range and the robustness of the sensing scheme can be extended using machine learning algorithms, which shows promise for potential applications in therapeutic drug monitoring, food processing, forensics and veterinary science.

In the present exploratory work, Calotropis Gigantea Stem (CGS) fiber-Flax Reinforced Natural Fiber Composites were fabricated by Compression Molding Method. The CGS composites were developed by using epoxy resin LY556 as the matrix material and the hardener-HY951 the organic fiber as the Support material. Then, the developed CGS composites were tested to evaluate the mechanical properties such as Tensile Strength, Flexural Strength, and Impact Strength. Additionally, a Pin-on-Disc Wear tester was used for evaluating the wear properties of CGS composite materials. It was found that normal load played an important role in wear as well as friction. In the current investigation, at 30 N load, wear testing pairs exhibit the highest wear loss and high friction.

Dental implants have a triumph pace of 90–98%, which in clinical terms is essentially high. Implant failure may occur at earlier or later stage. In assessment of the drawn-out accomplishment of a dental implant, the reliability and the stability of the implant–abutment play a vital role. In general, the achievement of the treatment relies upon numerous factors influencing the implant, implant–abutment and abutment–prosthesis interfaces. Early implant failure occurs due to the improper mechanical stability. This study researches the stress distribution in an implant with different implant abutments with different height and angle in different loading criteria. The abutment heights are 5.50 mm, 3.50 mm and 3.60 mm respectively. The loading conditions are applied in vertical and 30˚ angle with the value of 36 N & 100 N. Cobalt chromium alloy is used which has the superior properties like high stiffness, tightly polished, wear resistant and also it is used to avoid crevice corrosion. Computational models of abutment types with different heights were modeled using CAD software and Analyzed with FEA software for finding out the total deformation, Maximum principle stress, and Maximum shear stress. Based on the structure of a dental implant system, it gives significant performance. The minimum and maximum total deformation, Maximum principle stress, and Maximum shear stress were noted in the Type 3 under 36 N vertical condition and Type 1 under 100 N under 30˚ respectively.

In friction stir welding, lesser tool life restricts the usage of non-circular pin in friction stir welding tool eventhough it delivers comparatively better weld joints than circular pin. Process peak temperature during the process affects the shear strength of the flowing material around the tool pin. Maintaining the process peak temperature as low as possible improves the properties in heat affected zone but on the other hand it increases the stress on the tool pin.Especially on the usage of non-circular pin, the pin surface experiences uneven stress distribution and causes premature tool failure. In this paper, optimum thermal environment through proper selection of process parameters and dwell period with respect to the pin geometry are analysed. A comparative analysis is also made to understand the impact of increase in flat surfaces in the pin surface on weld quality in the view of developing a suitable thermal environment that can improve tool life without compromising joint strength. Apart from this, optimum dwell period for the chosen tool pin geometry is analysed based on the empirical softening temperature of the material.

Nowadays, Organic fiber composites are utilized in different designing applications to expand the quality, upgrade the carrying load, and reduce the product cost. Untreated banana and jute fiber are taken to develop a hybrid natural composite for the current investigation. The specimen was produced using epoxy resin-LY556 as the matrix content and HY951 as hardener in compliance with the ASTM D-3039 / D-256 specification. The fibers are randomly chocked fiber using the hand-layup manufacturing technique. The wear tests were performed using an ASTM-G99 standard Pin-on - Disk wear tester. Wear test performed on prepared standard specimen with different percentages. It utilized to locate the most significant parameter that impacts the reactions. The outcomes showed that the applied load fundamentally impacts the reactions contrasted with sliding velocity and sliding distance.

In the present research, work focus has been given to determine mechanical properties of biodegradable industrial waste tea leaf fiber (WTLF), banana and flax fiber reinforced hybrid polymer composites using experimental approach. Banana fibers and WTLF were alkali treated with 5% NaOH solution. The hybrid composite laminates were manufactured using manually operated compression moulding machine with the volume fraction of 40:60 (Fiber: Matrix). As per ASTM standard, the mechanical characteristics were studied. The experimental results showed excellent mechanical characteristics for 5 wt% WTLF and 25- wt% banana fiber reinforced hybrid composites. The fractography analysis of untreated and alkali treated composites were examined using Scanning Electron Microscopy (SEM) and results revealed that superior mechanical bonding existed between fiber and polymer in case of alkali treated fiber composites.

In this investigation, the dynamic mechanical properties of Indian almond – Kenaf fiber composite were investigated and the effect of stacking sequence was analyzed. Four types of composites viz. k...

Aim: The aim of this study was to assess the influence of Proanthocyanidin (PA) application on bond strength of glass fiber posts to root canal dentin using self-etch adhesive luting system. Materials and Methods: Twenty single rooted mandibular premolars, freshly extracted for orthodontic purpose, were decoronated below the cementoenamel junction, and standardized to 14mm in length. Post space preparation was done upto No 3 Peeso reamer during which canals were irrigated with conventional irrigation protocol. Teeth were randomly divided into two groups (n=20 each) Group 1: Pre-treatment with PA and Group 2 served as the control group. Both Groups were restored with fiber posts bonded with RELYX U200 self-etch adhesive system. Teeth were then stored in distilled water for three months at 37° C. One mm slices were obtained and push-out bond strength testing was performed. Failure patterns were assessed under stereomicroscope at 20x magnification. Results: Individual bond strength values were calculated and statistically analysed with the chi-square test and independent-t-test. A statistically significant difference existed between the two Groups (p

The organic semiconducting polymer dots (Pdot) or nanoparticles exhibited a promising efficiency as photocatalyst for hydrogen production. This study reported a new Pdot-based photocatalyst constructed in the form of Donor-Acceptor-Metal cocatalyst (D-A-Mcat). These D-A-Mcat Pdots systems consisting of fluorene (F) as the donor, thienyl-benzo-dithiophene-dione (TBDD) as the acceptor and [Ir (TPy)2 (acac)] as the metal complex, and their structural, thermal, electrochemical and photophysical properties were systematically demonstrated for the first time. Introducing the cyclometalated iridium (III) complex comonomer into the polymer chain resulting in PFTBDD-IrTPy Pdots showed enhancement of the hydrogen evolution rates, which is over 20-times higher than those of pure polymer (PFTBDD Pdots) under otherwise identical conditions. In addition, the optical and electrical measurements indicated that the cyclometalated iridium (III) part have an important function for inhibiting the charge recombination of the PFTBDD-IrTPy Pdots during the photocatalytic reaction. The result strongly implies that inserted catalytic amount of Ir(III)-complex into the D-A polymers is beneficial for the enhancement of photocatalytic hydrogen evolution, which can inspire further optimization and greater molecular design strategies at a low-cost are highly desirable for the development of high-performance in photocatalysis.

To assess the impact of Diatomaceous Earth (DE) as a source of silicon on soil physical-chemical properties, yield attributes and clean coffee yield of Arabica coffee cv. Chandragiri, field experiments were conducted during the year 2017-18 and 2018-19 at Central Coffee Research Institute, Karnataka, India. Study revealed that, different doses of DE as soil application and as foliar spray (3 times) significantly increased the soil available silicon status from 38.19 to 41.63 mg kg− 1in 2018, 34.16 to 49.28 mg kg− 1 in 2019 and 36.18 to 46.04 mg kg− 1 on pooled basis and leaf available content from 0.40 to 0.79% in 2018, 0.43 to 0.83% in 2019 and 0.42 to 0.81% on pooled basis, respectively as compared to T1 − 100% RDF (Control). In addition, it enhanced the uptake of major nutrients and reduced the incidence of micronutrient during both the years of study and on pooled basis. Among different treatments, T7 -treatment supplemented with 100% RDF + 200 kg DEha− 1 + 0.5% foliar spray @ 3 times recorded significantly highest clean coffee yield (731 kg ha− 1) which was statistically on par (702 kg ha− 1) with T8- 75% RDF + 200 kg DE ha− 1 + 0.5% foliar spray @ 3 times during both the years of study increase in yield 27.63% as compared to T1- 100% RDF (Control) (529 cc kg ha− 1). The same trend was noticed in coffee beans grades, nutrients status in plants and post-harvest nutrient status in the soil. The impact of DE on pest and disease incidence could not be established either of the seasons, in a convincing manner. The net return and B: C ratio was highest in T7 (1.43) and T8 (1.40) compared with T3 (1.02). The study emphasized that use of silicon in Arabica coffee plantation is an alternative material which can be used for improving soil fertility and supplementary input for improving the production in coffee.