Papers by Author: Siddaramaiah

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Authors: D.V. Gowda, N. Rajesh, H.G. Shiva Kumar, Siddaramaiah
Abstract: The purpose of the present study was to compare the in vitro release and to findout the bioavailability of a 75 mg indomethacin capsule (Microcid®SR - reference - product A) was equivalent to optimized formulation (indomethacin loaded microspheres – test – product B). Indomethacin (IM) loaded carnauba wax fat microspheres were prepared by using meltable emulsified dispersion cooling induced solidification technique utilizing a wetting agent. Solid, discrete, reproducible free flowing microspheres were prepared. The yield of the microspheres was up to 92%, having smooth surfaces, with free flowing and good packing properties, angle of repose, % Carr’s index and tapped density values were within the limit. More than 98.0% of the isolated spherical microspheres were in the particle size range of 1135 - 1360 mm were confirmed by scanning electron microscopy (SEM). The drug loaded in microspheres was stable and compatible, as confirmed by DSC and FTIR studies. A single dose, randomized, complete cross over study of IM (75 mg) microspheres was carried out on 10 healthy male and female Albino sheep’s under fasting conditions. The plasma was separated and the concentrations of IM were determined by HPLC-UV method. Plasma IM concentrations and other pharmacokinetic parameters obtained were statistically analyzed. Based on this study, is it possible to conclude that drug loaded microspheres and Microcid®SR capsule are bioequivalent in terms of the rate and extent of absorption.
Authors: T. Jeevananda, O.G. Palanna, Joong Hee Lee, Siddaramaiah, C. Ranganathaiah
Abstract: The present study investigates the effect of the carboxylated multi-walled carbon nanotube (0~3 wt %) content on the electrical and thermal properties of high density polyethylene/carbon black/carboxylated multi-walled carbon nanotube (HDPE/CB/c-MWNT) hybrid nanocomposites. The room temperature electrical resistivity and positive temperature coefficient (PTC) intensity of the nanocomposites significantly improved with the addition of c-MWNT. However, the heat of fusion decreases as the amount of c-MWNT increases. Further, the microstructural parameters such as the fractional free volume (Fv) and free volume hole size (Vf) of the nanocomposites shows appreciable changes around the percolation threshold. Secondly, the PALS results seem to correlate well with the electrical and thermal properties of the composites.
Authors: R. Indu Shekar, P.M. Damodhara Rao, Siddaramaiah, V.C. Padaki, Nam Hoon Kim, Joong Hee Lee
Abstract: The extruded poly ether ether ketone (PEEK) and glass fibre were used to obtain the co-woven hybrid fibre fabrics and converted into composites using compression moulding technique. The effect of shear stress and shear rate on the shear viscosity of PEEK was investigated to optimise the process conditions for converting hybrid fabrics into composites. The mechanical properties such as flexural strength and inter laminar shear strength (ILSS) as a function of number of layers of fabric have been evaluated. Low velocity (2.1 m/s) repeated drop weight impact tests were carried out on the fabricated composites at 5 and 10 J incident energy. Dielectric properties as a function of temperature and frequency have been carried out. Flammability behaviour of composites has been carried out using cone calorimeter. The data generated shows that glass-PEEK based composites are excellent potential materials for advanced structural composites.
Authors: S.P. Kumaresh Babu, Anand Chairman, N. Mohan, Siddaramaiah
Abstract: The effect of tungsten carbide (WC) particulate fillers incorporation on two-body abrasive wear behaviour of glass fabric reinforced-epoxy (GE) composites was investigated and findings are interpreted. The wear behaviour of the composites were performed using pin-on-disc tester at varying abrasive distances viz., 25,50,75 and 100 m at a constant load of 20 N. The experiment was conducted using two different water proof silicon carbide (SiC) abrasive papers and at two different velocity under multi-pass condition. The wear loss of the composites found increasing with increase in abrading distances. A significant reduction in wear loss and specific wear rates were noticed after incorporation of WC filler into GE composite. This result indicates a significant improvement in wear resistance after incorporation of WC filler. The WC loaded systems exhibit less wear of matrix during abrasion which in turn facilitates lower fiber damage, due to the presence of WC particles on the counter surface which act as a transfer layer and effective barrier to prevent large-scale fragmentation. The worn out surface features were examined through scanning electron microscopy (SEM) in order to probe the wear mechanism.
Authors: E. Basavaraj, Siddaramaiah, Joong Hee Lee
Abstract: The sliding tensile and dry sliding wear behaviours of nylon 66/1 wt % carbon black composites with varying amounts viz., 0.5, 1, 2 and 3 wt % of molybdenum disulphide (MoS2) have been studied. The wear behaviour of nylon 66/carbon black/MoS2 composites has been investigated using pin-on-disc tester under dry condition. Wear characteristics have been measured at different sliding velocity, loads and sliding distances. The coefficient of friction of the composites increases with increase in normal load due to changes in the area of contact. Wear mechanisms were established using SEM.
Authors: S. Roopa, Siddaramaiah
Abstract: Castor oil based polyurethane (PU) interpenetrating polymer network (IPN) has been prepared by using castor oil, toluene diisocyanate and styrene monomer. The coconut shell powder (CSP) particulate filler with different weight ratios viz., 0, 5, 10, 20 and 30 wt % were incorporated into polyurethane/polystyrene (PU/PS, 90/10) IPN. The effects of CSP particulate filler loading on the physico - mechanical and thermal properties of PU/PS IPN biocomposites have been studied. From the tensile behavior, it was noticed that a significant improvement in tensile strength and tensile modulus with increase in CSP filler content. It was found that the degradation of all composites takes place in two steps. Degradation kinetic parameters were obtained for the composites using Broido (BR), Coats–Redfern (CR) and Horowitz-Metzger methods (HM). The damping property reduced after the incorporation of CSP filler. Morphology of the cryo-fractured composites was studied using scanning electron microscopic technique (SEM).
Authors: T.M. Mruthyunjaya Swamy, Siddaramaiah, Joong Hee Lee
Abstract: A series of aqueous solutions of blends based on polyethylene oxide (PEO) and hydroxypropyl methyl celloulose (HPMC) were prepared. The solution of the blends thus obtained was analyzed for miscibility. The effects of compositions of blends and temperature (30 and 500C) on miscibility have been reported. The Huggin plots deviate from linearity according to the degree of compatibility of PEO/HPMC blends at entire concentration range. Interaction parameters have been evaluated for all blends to probe the miscibility. The blends were also characterized by sophisticated techniques such as FTIR, DSC, TGA and SEM.
Authors: N. Mohan, S. Natarajan, S.P. Kumaresh Babu, Siddaramaiah, Joong Hee Lee
Abstract: The effect of ultrahigh molecular weight polyethylene (UHMWPE) on solid particle erosion behaviour of aramid fabric reinforced-epoxy (A-E) hybrid composites was investigated. The aramid fabric reinforced-epoxy hybrid composites have been fabricated with and with out UHMWPE filler. The solid particle erosive wear was evaluated at different impingement angles from 300 to 90 0 at constant velocity and at constant standoff distance .The silica sand of size 30 -50 and 60 -80 μm was used as erodent. The results show erosive rate of UHMWPE filled aramid- epoxy composite shows lowest value. The presence of UHMWPE in epoxy matrix gives good bonding between filler and matrix. The morphologies of eroded surface were examined by the SEM in order to establish the erosion mechanism of the composites.
Authors: Siddaramaiah, Manjula Koregala Sidde Gowda, Joong Hee Lee
Abstract: Polyurethane (PU)/starch biocomposites have been prepared with different weight fractions of starch (viz., from 0 to 40 wt %). The fabricated PU/starch composites were characterized by mechanical properties and thermal (DSC and TGA) behaviors. Microcrystalline parameters were calculated using X-ray profile. Water uptake and its effect on mechanical properties have been evaluated.
Authors: Peng Li, Siddaramaiah, Ok Kyung Park, Nam Hoon Kim, Seok Bong Heo, Joong Hee Lee
Abstract: A series of nanocomposite (NC) hydrogels were synthesized by in-situ polymerization of acrylamide (AAm) monomer using laponite XLS clay as a crosslinker. This paper focused on water absorbency of the NC hydrogels with various clay contents, at various pH values and ionic strengths. The influence of pH value on swelling behaviors showed that a maximum swelling ratio was observed at pH 11. The swelling abilities of the NC composites decreased in saline solution strength. Heat treatment of NC hydrogels improved the swelling capacity of the hydrogels.
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