822 research outputs found

    Performance evaluation of Mg-AgCI batteries for underwater propulsion

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    Magnesium-silver chloride seawater activated reserve pile-type battery was exclusively used in all underwater vehicles as a source of power due to its high energy density and power density. Various tests have been conducted on fully assembled battery to test its performance, suitability and compatibility. However, it is also essential that the battery is subjected to failure mode studies to understand the limitations of the battery and to analyse the vehicles performance under such situations. Various possible failure modes that the battery might experience during its usage as propulsion source in the underwater vehicle are identified, and the performance evaluation of scale9 down model (I O-cell module) of the battery has been carried out in the laboratory. The results are discussed to understand the electrochemical system and its effect on the overall performance of the vehicle. It has been observed that while some failure modes were found to affect the vehicles' performance adversely, only some failure modes are detrimental to the vehicle's performance

    Temperature Profiles in a Disc Brake

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    The Science of heat transfer allows us to determine the time rate of energy transfer caused by non equilibrium of temperatures. The importance of heat transfer in proper design of Automobiles has long been recognized. In this paper we determined the transient temperature distributions in a disc brake during a single brake application using Finite difference numerical technique. Hyperbolic heat conduction which includes the effect of the finite heat propagation is gaining importance. It is necessary to consider hyperbolic heat conduction in problems involving short time intervals and for very high heat fluxes. Here we considered both parabolic and hyperbolic heat conduction and the results are evaluated numerically, represented graphically and analyzed by comparing the temperature profiles corresponding to parabolic and hyperbolic heat conduction

    X-Ray Peak Broadening Analysis and Optical Studies of ZnO Nanoparticles Derived by Surfactant Assisted Combustion Synthesis

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    In this paper, synthesis of ZnO nanoparticles is done by a simple and facile surfactant assisted combustion synthesis. The synthesis of ZnO nanoparticles has been prepared using Zinc nitrate as a precursor material, glycine as a fuel with the support of non-ionic surfactant TWEEN 80. The obtained ZnO nanoparticles have been studied using characterization techniques like X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and UV-Vis Spectroscopy. XRD results reveal that the sample is crystalline with a hexagonal wurtzite phase. X-ray peak broadening analysis was used to evaluate the crystallite sizes and lattice strain by the Williamson-Hall (W-H) analysis. Further appropriate physical parameters such as strain, stress, and energy density values were also calculated using W-H analysis with different models, viz, uniform deformation model, uniform deformation stress model and uniform deformation energy density model. Transmission electron microscopy (TEM) result reveals that the ZnO nanoparticles sample is spherical in shape showing particle sizes less than 40 nm. The optical properties of ZnO nanoparticles were studied by UV-Vis spectroscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3102

    Preparation and Characterization of CuO Nanoparticles by Novel Sol-Gel Technique

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    Recent developments of nanosize materials of metal and metal oxide particles are intensively pursued because of their prominence in different fields of applications. Among all the transition metal oxides, CuO is a potential candidate for the application of magnetic storage devices, solar energy transfer, sensors, and super capacitors etc. Moreover CuO nanoparticles act as a good catalyst in some of the chemical reactions. CuO nanoparticles were prepared by novel sol-gel method. In this technique CuCl2.6H2O is added with acetic acid and heated to 100 Β°C with continuous stirring. To control the ph of the above solution, NaOH is added to the solution till ph reached desired value. The color of the solution changed from blue to black with precipitation. The black precipitation was washed 3 – 4 times with distilled water. Finally the solution was centrifuged and dried in air for one day. The CuO nanoparticles were characterized by studying their structure with X-ray diffraction and composition by energy dispersive X-ray analysis. The size of the nanoparticles is estimated by particle size analyzer and transmission electron microscopy. The optical studies were carried out with Uv-Vis spectrophotometer. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2960

    Effect of Co Doping on Structural and Magnetic Properties of ZnO Nanoparticles Synthesized by Novel Combustion Synthesis

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    ZnO is a wide band gap semiconductor (3.37 eV) with a high exciton binding energy (60 meV), which has wide applications in advanced optoelectronic devices. The theoretical prediction of room temperature ferromagnetism will be possible through the investigation of diluted magnetic semiconductors such as transition metal doped ZnO, especially Cobalt doped ZnO. The aim of the work is to synthesize Zn1 – xCoxO (x = 0 and x = 0.20) nanostructures through a novel urea based auto combustion method and its characterization. The Structural and Magnetic studies of the synthesized Zn1 – xCoxO Nano powders were carried out by X-Ray diffraction (XRD) technique and Vibrating Sample Magnetometer (VSM), respectively. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3097

    Synthesis, Characterization and Density Functional Study of LiMn1.5Ni 0.5O4 Electrode for Lithium ion Battery

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    This paper analyses material issues of development of Li-ion batteries to store electrical energy. The performance of the battery is improved by developing the high energy density cathode materials at Nano level. This paper explains the synthesis of most interesting cathode material Lithium Manganese Spinel and its derivatives like transition metal oxide (LiNi0.5Mn1.5O4) using Co-Precipitation chemical method; it is one of the eco-friendly ,effective, economic and easy preparation method. The structural features of LiNi0.5Mn1.5O4 was characterized by XRD – analysis indicated that prepared sample mainly belong to cubic crystal form with Fd3m space group ,with lattice parameter a 8.265 and average crystal size of 31.59 nm and compared the experimental results with computation details from first principle computation methods with Quantum wise Atomistix Tool Kit (ATK),Virtual Nano Lab. First principle computation methods provide important role in emerging and optimizing this electrode material. In this study we present an overview of the computation approach aimed at building LiNi0.5Mn1.5O4 crystal as cathode for Lithium ion battery. We show each significant property can be related to the structural component in the material and can be computed from first principle. By direct comparison with experimental results, we assume to interpret that first principle computation can help to accelerate the design & development of LiNi0.5Mn1.5O4 as cathode material of lithium ion battery for energy storage. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3581

    A new analytical method for determination of ledipasvir and sofosbuvir in pharmaceutical formulations by HPLC method

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    A simple, Accurate, precise method was developed for the simultaneous estimation of the Sofosbuvir and Ledipasvir in Tablet dosage form. Chromatogram was run through Std Discovery C8 150 x 4.6 mm, 5m. Mobile phase containing Buffer 0.1% OPA: Acetonitrile taken in the ratio 60:40 was pumped through column at a flow rate of 1 ml/min. Buffer used in this method was 0.1% OPA buffer. Temperature was maintained at 30Β°C. Optimized wavelength selected was 260 nm. Retention time of Sofosbuvir and Ledipasvir were found to be 2.367 min and 3.436 min. %RSD of the Sofosbuvir and Ledipasvir were and found to be 0.6 and 0.5 respectively. %Recovery was obtained as 99.61% and 99.80% for Sofosbuvir and Ledipasvir respectively. LOD, LOQ values obtained from regression equations of Sofosbuvir and Ledipasvir were 0.67, 2.02 and 0.70, 2.12 respectively. Regression equation of Sofosbuvir is y = 4266.x + 7700, and y = 4861.x + 2656.of Ledipasvir. Retention times were decreased and run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control test in Industries

    Ultrafine aluminium: Quench collection of agglomerates

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    Combustion of aluminized solid propellants exhibits phenomena associated with accumulation, agglomeration, ignition, and combustion of ultra-fine aluminium particles. In this study, agglomeration phenomenon of ultra-fine aluminium in solid propellant combustion is investigated using quench collection experimental technique over the pressure ranges from 2MPa to 8MPa. The ultra-fine aluminium powder synthesized by Radio Frequency Induction Plasma technique having harmonic mean size of 438nm is used for agglomeration study. The quenching distance is varied from 5mm to 71mm from the propellant burning surface to estimate the effect on agglomerate size. The morphology and chemical compositions of the collected products were then studied by using scanning electron microscopy coupled with energy dispersive (SEM-EDS) method. Under the explored experimental conditions, the results confirm that ultra-fine aluminium propellant show aggregation/agglomeration with the size ranging from 11 – 21 ΞΌm in combustion products. Smaller diameter condensed phase products will likely decrease two-phase flow loss and reduce slag accumulation
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