This study is devoted to characterize the microstructural and mechanical state of polycrystalline 304 L stain-less steel (SS), deposited on Si substrate by the ion beam sputtering technique using the ion beam assisted deposition (IBAD) processes, by using X-ray diffraction method. The conventional Sin(2) Psi method shows that both stress and stress-free lattice parameters are found to be decrease under the IBAD processes. The size of coherently diffracting domains D and microdistortions (1/2) in thick films are obtained using the integral width (IW) methods. The measurements show that D increases and (1/2) decreases. The texture analysis confirm the < 110 > texture that increases with assistance rate.
In this paper, CuInS2 thin films were prepared by spray pyrolysis method at different substrate temperatures (T-s). The obtained films were characterized by Raman spectroscopy, UV-Vis spectrophotometer and 4-point probe technique. The results showed that all of the spray pyrolyzed thin films have chalcopyrite structures. The CuInS2 thin films elaborated at 375 degrees C for 30 min possessing 1.47 eV direct band gap. The observed band gap value for HK-R2 (1.47 eV) is very close to the theoretical band gap value of CuInS2. The value of the direct band gap would increase with increasing the substrate temperature. The resistivity of films increases from 5.47 x 10(-2) to 6.33 x 10(+1) Omega.cm with the increase in the substrate temperature from 350 degrees C to 400 degrees C. For CuInS2 thin films, properties like structural, optical and electrical showed progressive behavior with substrate temperature.
In this paper, a thermo-mechanical model of vibration of nano beam induced by a thermal shock is improved in the context of two-temperature generalized thermoelasticity without energy dissipation. In the Laplace transform domain, the analytic solution has been derived while the inversion of the Laplace transforms has been calculated numerically. The numerical results have been represented in figures with some comparisons to stand on the effects of the two-temperature parameter on all the studying fields.
Recent years saw a growing number of research papers on electrospun nanofibers for bone regeneration. Our hypothesis is that the electrospun nanofibers need further tailoring at sub-micron length scales to mimic the natural bone for enhanced biocompatibility and bone regeneration. We nano-engineered electrospun fibers via nanocomposite of Polycaprolactone (PCL) and nano-Hydroxyappatite (nHAP). The nHAP is synthesized via a hybrid method, hydrothermal process followed by microwave irradiation. The fiber morphology was characterized by scanning electron microscopy (SEM) while its composition by energy dispersive X-ray analysis (EDX), ATR-Fourier transform infrared spectroscopy (ATR-FTIR), powder X-ray diffraction (XRD) and Contact angle (CA) measurement. The scaffolds showed a nano- porous architecture and incorporation of nHAP in the nanofibers. There was uniformity in the size of the fibres and were randomly aligned. Cell culture studies with MG63 cells shows increased proliferation on the composite scaffold. The study reveals that the PCL-nHAP composite fiber mat showed a nano- porous environment for better cell adhesion and containing nHAP is osteogenic and can serve as a potential bone graft material.
Carbon quantum dots (CQDs) serve as a new class of 'zero dimensional' nanomaterials in the carbon class with sizes below 10 nm. As light emitting nanocrystals, QDs are assembled from semiconductor materials, from the elements in the periodic groups of II-VI, III-V or IV-VI, mainly thanks to impacts of quantum confinement QDs have unique optical properties such as brighter, highly photo and chemical stable, with broad absorption, narrow and symmetric emission spectrum. A substantial QDs feature is that their emission wavelength can be fine-tuned by adjusting their size and chemical composition. Nowadays carbon nanoparticles are applied on the island of single electron transistor and Nano-transistors, and fluorine because of its sustainability is one of the best materials inter alia. The basis of Single electron devices (SEDs) is controllable single electron transfer between small conducting "islands." In this paper transmission coefficient as a main transport factor need to be explored in this work the transmission coefficient for multi potential barriers is investigated. All theoretical expressions such as height, width of potential barriers, distance between them and carrier property are included to have exact value of transmission coefficient. Then quantum current of double barrier single electron transistor (SET) is modelled and models current-voltage characteristic based on quantum transport and the electronic properties due to the dependence on structural parameter are analysed.
In nanoscale administration, Tunnel field effect transistor (TFET) has demonstrated the most encouraging device as it gives higher Ion/Ioff ratio and steeper Subthreshold swing (SS) than traditional MOSFET. In any case, doped devices experience the ill effects of unexpected intersection and irregular dopant variance (RDF) issues. Along these lines, out of the blue we have propose a 2-D expository model for a surface potential and electric field for a single material gate dual electrode doping less tunnel field effect transistor (SMG-DEDLTFET). Since the proposed show accomplish the coveted focus with the assistance of charge plasma method, we don't have to complete a physical doping which will bring about the concealment of above issues. The model articulation for surface potential and electric field are produced by settling 2-D Poisson's condition under reasonable limit conditions and the outcomes are approved with reenactment aftereffect of SILVACO TCAD device.
In this paper we study the screening length (SL) in opto-electronic materials in the presence of intense electric field by formulating the new dispersion relation. It has been found taking n-InAs, n-InSb, n-Hg1-xCdxTe, n-In1-xGaxAsyP1-y lattice matched to InP, as examples that the SL decrease with increase in electron concentration for all types of materials. The results for the two band model of Kane are greater than the same of the three band model of Kane. The influence of spin orbit splitting constant for perturbed three band model of Kane enhances the numerical values of the SL as compared with the perturbed two band model of Kane and the variations are totally band structure dependent. The Screening Length for all the materials becomes more or less constant with the electric fields up to a certain values of the external electric field (depending on the values of the constants of the energy band structure of a particular material) and then decreases smoothly with increasing electric field, which reflects the variation of the density state function (DOS), since the Screening Length in any material under any physical condition is directly influenced by the corresponding (DOS) function for the whole range of the electric field. The variation for with respect to electric field is in conformity with the corresponding variation of the DOS versus electric field. We observe that the Screening Length decreases with increasing alloy composition for In1-xGaxAsyP1-y lattice matched to InP and Hg1-xCdxTe in accordance with both perturbed three and two band models of Kane. Under strong magnetic quantization the SL oscillates with inverse quantizing magnetic field.
The objective of the present study is to prepare AgCl nanoparticles (AgCl NPs) of different morphologies by using various quantities of low-cost Ocimum sanctum (OS) leaf extract under microwave-assisted route. Likewise, the current study is focused to compare the particle size, morphology, antibacterial, and photocatalytic activity of AgCl NPs synthesized in different amounts of OS leaf extract. The crystalline structure, morphology and optical absorption of synthesized products were studied using powdered X-ray diffraction (PXRD), scanning electron microscopy (SEM) and UV-Visible (UV-Vis) spectrophotometer. Sequentially, the synthesized products were further investigated by using Fourier transform infrared spectrometry (FTIR), and Energy dispersive X-ray diffraction analysis. The PXRD and SEM results indicate that the AgCl NPs with different particle sizes and morphologies are obtained when different quantities of the extract are used in the synthesis process. When the different AgCl NPs samples were used as a photocatalyst, the MB degradation is achieved about 73.7%, 79.2%, and 98.7% respectively. It is found that the among various AgCl samples highest amount of OS leaf extract used AgCl sample was showing better performance than other samples due to the less particle size. Thus, the current study elucidates green microwave approach to synthesize AgCl NPs is reliable, cost-effective and efficient and the OS leaf extract acts as eco-friendly reducing and capping agent on the surface of AgCl NPs. Though, antibacterial activity and photocatalytic degradation of methylene blue [MB] dye were studied for different AgCl samples synthesized using various quantities of OS leaf extract.
This study is studied and established characterization of the efficient thermal insulating layer of a composite tow-plaster. The characterization of thermal insulating material is proposed from the study of the thermal impedance in dynamic two-dimensional frequencial dynamics conditions. Thermal exchange phenomena between a wall kapok-plaster and its environment are presented. Study electrical equivalent model was used to show different wall behaviors: for lows pulsation, wall behaves's as inductor the variation of the heat stream density. For evolution of temperature and density of heat stream under the influence of the excitator pulsation on the front panel. The thermal inertia of the wall is also dependent on the heat exchange coefficient on the surface of the material, its thermo physical properties and initial temperature of the material.
The aim of this study was to prepare PVP/TiO2 nanofibers containing Cerium and investigate antibacterial properties of prepared nanofibers. In order to see the influence Ce doped at different ratios on the properties of TiO2 nanofibers, we prepared one pure TiO2 and Ce doped TiO2 nanofiber samples successfully by electrospinning method. 1, 2, 3, 4, and 5 wt% Ce doped TiO2 nanofibers produced at constant voltage 20 kV, constant height 8 cm and with a constant rate 0.1 mL/h. The antibacterial activities of the nanofibers were tested by using Staphylococcus aureus. The results showed that the antibacterial activity of TiO2 improves with doping of Ce. Characterization of the prepared samples was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the differential thermal analysis/the thermal gravimetric analysis (DTA/TGA) methods.
The Poly(Vinylidene Fluoride)/carbon nanotubes (PVDF/CNTs) piezoelectric composite films for electrical rotors have been fabricated using a modified electrospinning device with a rotating collector. beta phase dominant ferroelectric PVDF thin films with a remnant polarization of 3.2 mu C/m(2) were achieved by optimizing the concentration of 0.5 wt% of CNTs. The effect of concentration of CNTs in modifying PVDF crystalline phase structure has been enhancing beta phase transformation in PVDF. This aspect has been confirmed throuhgt X-ray diffraction and infrared spectroscopy data. These structures were morphologically analyzed by scanning electron microscopy (SEM) with 600 divided by 800 nm diameter of CNTs-PVDF. Overall, our results highlight the potential of the conductivity of the solution and the morphology of the mat obtained by electrospinning are related by the influence of the CNTs concentration.
This paper is designed to examine the problematic case of a thin slim strip being positioned in a magnetic field while it was subjected to a source of moving heat. This will be applied by considering the governing equations with a new viscous parameter and the theory of fractional order. This research used the generalized thermos viscoelasticity theory assuming thermal relaxation constructed by the Lord and Shulman (L-S) theory to deal with the problem raised in the study. A testing of the governing equations was conducted and Laplace transform was used. Manipulation has been driven in the physical domain through MATLAP Program numerical method. Some figures had been displayed to be able to compare estimates for the impact of fractional viscous parameter, speed and time of a moving heat source on temperature, stress and displacement.
In this paper alternate low cost, easy to fabricate hole transport layer (HTL) and electron transport layer was proposed for efficiency enhancement of lead halide perovskite solar cell (LHPSC). SnS and Zn doped CdS thin film was prepared by successive ionic layer absorption and reaction (SILAR) method at room temperature. X-ray diffraction (XRD) confirms herzenbegrite orthorhombic crystal structure for SnS thin film and hexagonal wurtzite structure of CdS. To validate the concept of efficiency enhancement for experimentally designed SnS thin film as HTL and Zn doped CdS as ETL, solar cell capacitance simulation (SCAPS) was used. In SCAPS first result for experimental J-V of LHPSC with power conversion efficiency (PCE) 19.7%, V-oc of 1.08 V, J(sc) of 23.8 mA/cm(2) and FF of 76% were produced. Next SnS was applied as HTL and Zn doped CdS as ETL in SCAPS to analyze the effect. After optimization LHPSC solar cell in SCAPS reached up to a value of PCE 23.62% with V-oc of 1.10 V, J(sc) 25.53 mA/cm(2) and FF 84.32%.
Surface mechanical attrition treatment (SMAT) is measured to be a current approach for obtaining a nanostructured layer on the treated metal. In this paper, a nanostructured surface layer up to 450 +/- 20 mu m thick was induced on commercially used spring steel by SMAT. The effect of SMAT on microstructural features has been systematically characterized by optical microscope (OM) for cross-sectional observation, transmission electron microscopy (TEM) and X-ray diffractometry (XRD) analysis. The result shows an increase in strain in the surface layer due to grain refinement process. This involves an increase in dislocation density, formation of thin martensitic layers and twinned martensite. The SMAT also induce craters which is approximately circular depression in the surface prompt an increase in roughness value from 0.572 mu m to 1.978 mu m and decreases slightly upto 1.871 mu m when SMAT goes upto 75 min. These changes resulted in an increase of mechanical properties which were characterized as hardness increment, yield strength, tensile strength and also increases the % elongation after certain time of SMAT.
Increased static and dynamic power dissipation in the integrated circuits (ICs) are the main obstacle for growing demands of smart phones and laptops, which require semiconductor devices having low power operation. As the conventional MOSFET has a thermodynamic limit of 60 mV/decade at 300 K on subthreshold slope (SS), so the device based on the mechanism other than diffusion over a thermal barrier came into existence. In this regard, Tunnel-FET (TFET) has emerged as a promising replacement. Due to its lower subthreshold slope (<60 mV/decade at 300 K), reduced OFF-current (I-OFF), reduced power consumption, and negligible short channel effects, TFETs have achieved a lot of attention in the recent years. In the present research work, double-gate TFET (DG-TFET) device has been investigated. The simulation result shows a very good I-ON/I-OFF ratio (10(12)) and low SS (similar to 41.54 mV/dec). The DG-TFET has very low off current, I-OFF (similar to 10(-17) A/mu m) and ON-current of (I-ON) similar to 10(-5) (A/mu m) using gate bias in the vicinity of 0.5 V. In addition, we have optimized the device parameters, thus improving the I-ON current and the I-ON/I-OFF ratio yield for two kinds of technologies (using HfO2 or SiO2 as gate dielectric). A comparison between the two technologies was made. Gate to drain (C-gd) capacitance as function of gate to source voltage V-GS as well as drain to source voltage V-DS at frequency f = 1 MHz, C-gd is weaker using SiO2 as gate dielectric compared to HfO2.
A comparative study was made for the weldability of 4-mm-thick 5083 aluminum-alloy sheets using friction-stir welding (FSW), metal inert gas (MIG) welding and braze welding. FSW joint characteristics were obtained using the high-speed steel tool having conical pin with rotation speed of 1000 rpm and transverse feed rate of 28 mm/min with the tool tilt angle held constant at 2 degrees. MIG welding was carried out using Al5183 filler metal and UNIMIG-400 MIG welding machine with Ar as shielding gas. Braze welding was carried out using the acetylene flame with the AA4047 filler wire and Alu powder as a flux. Samples obtained in all the three cases were subjected to microstructural analysis, Vickers micro-hardness measurements and tensile-testing. Results indicated that of all the samples, FSW samples showed maximum tensile strength, approaching that of base metal. This could be attributed to wrought microstructure observed in the weld zone of FSW samples. Similarly, lower tensile strength of MIG and braze welded sample could be attributed to coarse grain microstructure and porosity observed in the respective samples. Variation of micro-hardness across the weld zone and base metal also gave insight into the relation between tensile strength properties and microstructural properties of these samples.
Nanotechnology with respect to green synthesis is the most interested area in material science today. Synthesis of metal oxide nanoparticles (MO NPs) by using plant-mediated materials is an economical and eco-friendly and is more affirmative in modern materials technology. In this study green synthesis of Co3O4 spinel, NPs is achieved from its metal salts by microwave assisted solvothermal method using pomegranate fruit peel extract as fuel. The UV-Vis spectroscopy analysis of pomegranate (Punica granatum) peel extract revealed the presence of polyphenolic compounds such as gallic acid, punicalagin A, punicalagin B and ellagic acid. The synthesized Co3O4 spinel NPs have been characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) UV-Vis spectroscopy (UV-Vis) and photoluminescence (PL) spectroscopy. The crystallographic studies from PXRD indicate, the crystalline nature of Co3O4 spinel NPs owing 40 +/- 2.5 nm particle size, and the same particle size is also been observed from the transition electron microscopy (TEM). FT-IR spectroscopic analysis confirms that, the existence of only cobalt and oxygen which indicates the purity of the Co3O4 spinel NPs. In addition, the antibacterial properties of Co3O4 spinel NPs were investigated against gram +ve and gram -ve bacteria such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumonia, and Morganella morganii.
Because of the chemical and thermal stabilities at high-temperature and oxidation resistance, the thermal barrier coatings (TBCs) possess significant importance in the protection of alloys at elevated temperature. It was researched that the layers of thermally grown oxides (TGO) restricts the applications because of the spallation, compositionally graded thermal barrier coatings by formation of near uniform non-clustered distribution of TGO enhances the thermal cyclic performance by delayed spallation. In this review, the simulation of failures of thermal barrier coated components during diverse applications by solid particles erosion testing at elevated temperature and high temperature corrosion attack in presence of sulfate and vanadate salts has been reviewed and disserted in detail. Also, this article gives contemplation on significance of composition gradient over the performance of thermal barrier coating while exposed to elevated temperatures of around 1200 degrees C.
In the present study, spent tea leaves ash (TLA) reinforced in varied weight ratios (0, 1, 2, 3 wt.%) with aluminium were utilized to fabricate aluminium matrix composites (AMCs) using the powder metallurgy (P\M) process. Scanning electron microscopy and X-ray diffraction technique was utilized for micro-structural characterization. Density along porosity measurement, hardness and dry sliding wear performance were evalauated to characterize the developed composites. Wear measurement were carried out on Pin-on-Disk wear testing machine at different reinforcement ratios of 1, 2, 3 wt.%, sliding distance of 300 m, 600 m, 900 m, loads of 10 N, 20 N, 30 N and sliding speed of 1.5 m/s, 2.0 m/s, 2.5 m/s to analyze the effect of these parameters. Taguchi's technique was used for planning of experiments to conduct experiments. Worn out surfaces of Al and Al-2% TLA composite were studied using SEM for predicting the contributions of TLA reinforcement on the wear mechanism.
Tin sulfide (SnS) is a non-toxic and earth abundant material belonging to group IV-VI, and due to its optimum band gap has been considered as a suitable material for absorber layer in photovoltaic solar cell applications. However, despite its optimum band gap for photovoltaic conversion the maximum power conversion efficiency achieved up to now in experimental devices for SnS-based solar cell is only 4.6%, which is far below its related Shockley-Queisser limit. In this paper, the main photovoltaic parameters of a SnS/CdS/ZnO solar cell are analysed with the aid of MATLAB and Solar Cell Capacitance Simulator software (SCAPS). The expected efficiency for a SnS/CdS/ZnO solar cell structure composed by layers without defects is about 28%. However, the performance of SnS-based solar cell is highly dependent upon material properties like band tailing, temperature, thickness of the absorber material and defects in the absorber layer and in the interface buffer/absorber. The effect of the defects on the overall performance of SnS-based solar cells is calculated and discussed and the results are compared with reported experimental SnS/CdS solar cells.
