Digital Eprints Services at Vignan's Foundation for Science, Technology & Research
Not a member yet
721 research outputs found
Sort by
Effect of grain refinement on corrosion rate, mechanical and machining behaviorof friction stir processed ZE41 Mg alloy,
No full textt The aim of the present work is to modify the microstructure of ZE41 Mg alloy by friction stir processing (FSP) and to study the influence of microstructure on the corrosion, mechanical and machining behavior. Microstructural observations revealed the prevalence of grain refinement from & 100 to 3.5 lm. The compound present at the grain boundary was observed to have
decreased to a great extent after FSP suggesting the formation of supersaturated grains. Hardness measurements indicated increased hardness after FSP which was attributed to grain refinement effect. Tensile tests showed increased yield strength after FSP without altering the percentage of elongation which was due to the grain boundary strengthening. Corrosion performance of FSPed ZE41 was found to be similar compared with ZE41 due to the synergy of grain refinement, decreased amount of secondary phase and development of supersaturated grains. Grain size was observed as significant factor on machinin
Surface modified LiCoO2 as cathode for Li Ion battery application
No full textSamarium oxide (Sm2O3) coated LiCoO2 particles were synthesized using resin coating process. The prepared samples were subjected to characterization using thermogravimetry analysis (TGA)/differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. The formation of phase pure LiCoO2 was confirmed from XRD studies. No diffraction peak was observed for Sm2O3 phase. SEM images confirmed the spherical particle morphology of bare and Sm2O3 coated LiCoO2 samples. The presence of oxidation and reduction peaks in the CV curve confirmed the de-insertion/insertion of Li ions out/into LiCoO2 structure
Preparation and quality evaluation of nutritionally enriched jam made from blends of Indian blackberry and other fruits.
Get PDFJamun (Syzygium cumini) is a tropical, underutilized fruit which is highly perishable in nature. It is a good source of vitamin C, tannins, gallic acid and anthocyanins and its beneficial effects are mostly due to the presence of bioactive compounds (pigments and phenolic compounds) in it. Due to astringent and fibrous nature, preparation of jam from jamun pulp is quite difficult, but other fruits (apple and kiwifruit) can be incorporated in it to improve its quality. This study aims to develop jam from blends of jamun with other fruits and analyse various physico-chemical, nutritional, textural and sensory properties. It was found that physico-chemical properties of jams were not found to vary greatly, but the jamun–kiwifruit jam was found to have fairly high amount of antioxidants(46.75 ± 0.67%), tartaric acid (26.24 ± 0.02 mg/100g sample), ascorbic acid (0.08 ± 0.01 mg/100 g sample) and lactic acid (23.95 ± 0.01 mg/100g sample) and lowest amount of 5-hydroxymethyl-2-furaldehyde (0.38 ± 0.04 mg/100 g sample). Jamun jam and jamun–kiwifruit jam possessed the texture required for jam while jamun–apple jam was found to be a relatively harder gel. Jam made with jamun and kiwifruit pulp was found to have highest acceptability on the basis of sensory evaluation
Kinetics of Reactive Dyed Pretreated Cotton Fabrics With and without using Salt
Get PDFMost of the cotton fabrics at present are dyeing using reactive dyes which requires large quantities of salt, further produce large amount of effluent load to the environment in the form of more salinity in the effluent water along with other pollutants. In order to reduce the salinity in the waste water lot of investigations were carried out. Cotton fabrics pretreated with chitosan were dyed with reactive dyes. Pretreated samples were dyed without using salt as an electrpolyte. The influence of pretreatment on kinetics in dye bath i.e rate of dye particle movement towards the fabric, wash fastness, rubbing fastness was determined. The results of this study shows that the pretreatment of cotton with chitosan increases dye uptake and shows good fastness to washing and rubbing same as that of conventional way of dyed samples. It was determined that chitosan was effective cross linking agent in salt-free dyeing of cotton fabrics
Relationship between Dopamine and Serotonin on the Effect of Ginkgo biloba Extract in the Treatment of Obsessive-compulsive Disorder in Rodents
Get PDFIn this study, the effect of EGb-761, the standardized extract of Ginkgo biloba at dose levels of 50, 100 and 200 mg/kg was investigated on experimental models of obsessive-compulsive disorder such as quinpiroleinduced compulsive checking in rats and marble burying behaviour in mice. Water maze test was used to evaluate the effect on spatial memory and the underlying mechanisms were predicted based on rat brain dopamine and serotonin levels. EGb-761 at 100 and 200 mg/kg showed signifi cant improvement against quinpirole-induced compulsions. A protective effect on memory task was observed in EGb-761-treated rats. This could be attributed to the increase in serotonin and decrease in the dopamine levels. The protective effect of EGb-761 in the treatment of obsessive-compulsive disorder is apparent through the performance in the open fi eld and marble burying behaviour
Design and Development of Environmentally Friendly Polybenzoxazine–Silica Hybrid from Renewable Bio-resource
No full textAbstract
In the present work, an attempt has been made to develop polybenzoxazine- silica hybrid through in-situ sol–gel method
using renewable bio-resource raw materials such as cardanol and furfurylamine for high thermal and flame retardant appli�cations. In this context, a new approach has been adopted to incorporate an inorganic component (MPTMS) in to cardanol benzoxazine (BZ–C–F) via chemical interaction between the unsaturated group of cardanol and mercapto group (–SH) of MPTMS by thermally initiated thiol-ene click reaction. The developed PBZ–C–F–silica hybrids were characterized for their molecular structure, thermal and flame resistant properties using modern analytical techniques. Data obtained from thermal and flame retardant studies, it is suggested that the developed PBZ–C–F–silica hybrid can be used in the form of coatings, sealants, encapsulants and matrices for thermally stable and flame retardant applications
An escalation of anticorrosion and microelectrical properties of polyurethane nanocomposites from green Brassica nigra oil
No full textAbstract Brassica nigra oil-based polyurethane composites have been synthesized and characterized by various analytical techniques such as Fourier transform infrared, NMR, X-ray diffraction, scanning electron microscope, atomic force
microscopy, DSC and TGA. Broadband dielectric spectroscopy confirms the improvement in the dielectric properties of the prepared composites (AGO/BNP/ PH) with respect to increasing AGO content. The analytical results conclude that graphene oxide-reinforced Brassica nigra oil-based polyurethane nanocomposites show improved thermal, Tg, dielectric constant and decreased dielectric loss with respect to different ratios of amine-functionalized graphene oxide. Further, the
corrosion resistance behavior analysis results conclude that the prepared bio-com�posites have excellent corrosion-resistant property (96.93%) compared to neat Brassica nigra oil-based polyurethane polymer, which can be used as coating
material for marine and also in microelectronic application
Particle Swarm Optimization approach for waterjet cavitation peening
No full textAn attempt has been made to solve water jet machining associated with cavitation peening problem through Particle Swarm Optimization (PSO) technique. The swarm initialization is started with Water pressure, stand off-distance and traverse speed. The fitness estimation of PSO is Residual stress,
Hardness and Surface profile roughness. These dependent and independent parameters are used in water jet machining to induce beneficial residual stress into the surface layer. These parameters would adversely affect and greatly influenced hardness and surface finish of the machine samples. The position of each particle and conversion of the particle position to velocity are carried out on the PSO algorithm to
find the appropriate optimum position of the particle. By following the above procedure, through the PSO algorithm, single order iteration equations are calculated for the independent parameter and it is found to have a correlation of 98% satisfactory limit with the experimental observations. With the developed PSO model, a minimum number of experimental runs will be sufficient to resolve any machining problems
that are associated with optimization
A Novel Approach for Minimization of Tool Vibration and Surface Roughness in Orthogonal Turn Milling of Silicon Bronze Alloy
No full textThe advanced manufacturing system is aimed to produce components at right quantity, quality and cost. Turnmilling is one of the advanced machining techniques that combines turning and milling processes for high metal removal rate. In orthogonal turn milling, bottom surface of the end mill cutter removes material from the surface of a rotating workpiece. Optimization of process parameters plays an important role in machining to improve quality and productivity and reduce production cost. In the present work, an advanced teaching learning based optimization (TLBO) technique was introduced to optimize process parameters in orthogonal turn milling of Silicon Bronze. Experiments were conducted at five levels of cutting speed, feed and depth of cuts. Experimental results of surface roughness and amplitude of cutter vibration were analysed using analysis of variance. The experimental results were also used to optimize process parameters through TLBO. Experiments were also conducted using TLBO optimized process parameters and the results were compared with TLBO results. The TLBO results were found to be in good agreement with target values of the responses. Artificial neural networks were developed for the surface roughness and amplitude of cutter vibration to verify optimizatio
Industrial potential of carotenoid pigments from microalgae: Current trends and future prospects
No full textMicroalgae are rich source of various bioactive molecules such as carotenoids, lipids, fatty acids, hydrocarbons, proteins, carbohydrates, amino acids, etc. and in recent year‟s carotenoids from algae gained commercial recognition in the global market for food and cosmeceutical applications. However, the production of carotenoids from algae is not yet fully cost effective to compete with synthetic ones. In this context the present review examines the technologies/methods in relation to mass production of algae, cell harvesting for extraction of carotenoids, optimizing extraction methods etc. Research studies from different microalgal species such as Spirulina platensis, Haematococcus pluvialis, Dunaliella salina, Chlorella sps., Nannochloropsis sps., Scenedesmus sps., Chlorococcum sps., Botryococcus braunii and Diatoms
in relation to carotenoid content, chemical structure, extraction and processing of carotenoids are discussed. Further these carotenoid pigments, are useful in various health applications and their use in food, feed, nutraceutical, pharmaceutical and cosmeceutical industries was briefly tocuhced upon. The commercial value of algal carotenoids has also been discussed in this review. Possible recommendations for future research studies are proposed