183 research outputs found
A Review on Characterization of Hybrid Fibre Reinforced Polymer Composite
Fibre reinforced polymer composite are well recognized materials for automobile, aerospace, packaging and construction industries due to its properties such as light weight, low cost and high specific strength. Hybridization of fibres has become very popular technique to increase the properties of single fibre reinforced polymer composite. This paper presents review  on mechanical properties, thermal properties, water absorption properties, dynamic mechanical analysis and tribological behaviour of hybrid fibre reinforced polymer composite. Finding of this study shows that hybridization can improved mechanical, thermal and dynamic mechanical property, and decrease water absorption property and wear rate
Effect of Sisal Fibre Loading on Wear and Friction Properties of Jute Fibre Reinforced Epoxy Composite
This paper presents an experimental study on wear and frictional properties of developed hybrid sisal/jute fibre reinforced epoxy composite. Composite are fabricated by hand lay-up technique keeping constant 30 wt. % of fibre content. Wear and frictional properties of hybrid composite is carried out at different operating parameters such as applied load (10-30 N), sliding speed (1-3m/s) and constant sliding distance 1000 m. Alkali treatment of fibres is used to increase the percentage reduction of wear rate and friction coefficient. The experimental results show that increase in specific wear rate and coefficient of friction is found on increasing the applied load and sliding speed.
Aerosol Characteristics at a high-altitude station Nainital during the ISRO-GBP Land Campaign-II
During the second land campaign (LC-II) organised by ISRO-GBP, extensive
ground-based measurements of aerosol characteristics were carried out over
Manora Peak (29.4oN; 79.5oE; 1951 metres above mean sea level), Nainital (a
high altitude station located in the Shivalik ranges of Central Himalayas)
during the dry, winter season (December) of 2004. These measurements included
the spectral aerosol optical depths (AOD), columnar water vapour content (W),
Total Columnar Ozone (TCO), total number concentration (NT) of near surface
aerosols, mass concentration of black carbon (MB), aerosol mass loading (MT),
and Global Solar Radiation. Based on these measured parameters, we present the
results on the near-surface and columnar properties of atmospheric aerosols at
Nainital.Comment: Published in the Proceedings of the ISRO-GBP Land-Campaign-II
meeting, Physical Research Laboratory, Ahmadabad (Inida), March 200
Comparative study of magnetic and magnetotransport properties of Sm0.55Sr0.45MnO3 thin films grown on different substrates
Highly oriented polycrystalline SSMO thin films deposited on single crystal
substrates by ultrasonic nebulized spray pyrolysis have been studied. The film
on LAO is under compressive strain while LSAT and STO are under tensile strain.
The presence of a metamagnetic state akin to cluster glass formed due to
coexisting FM and antiferromagnetic/charge order (AFM/CO) clusters. All the
films show colossal magnetoresistance but its temperature and magnetic field
dependence are drastically different. In the lower temperature region the
magnetic field dependent isothermal resistivity also shows signature of
metamagnetic transitions. The observed results have been explained in terms of
the variation of the relative fractions of the coexisting FM and AFM/CO phases
as a function of the substrate induced strain and oxygen vacancy induced
quenched disorder.Comment: 21 page
Research Notes : India : Induced parthenogenesis in soybean
A field of research currently gaining much interest is the irradiated-pollen-induced ovule transformation in plants. The interest lies mainly in the possibility of modifying the plant genome in a quicker and more economical way. The successful demonstration of such gene transfers have been achieved in Nicotiana (Pandey, 1975; Jinks et al., 1981), Brassica (Banga et al., 1983) and Lycopersicum (Zamir, 1983) for both qualitative and metric traits
Mechanical and Water Absorption Properties of Hybrid Sisal/Glass Fibre Reinforced Epoxy Composite
Our environment is being pullulated due to the great use of synthetic fibre as reinforcement for polymer composites. Natural fibres may be better choice for replacement of synthetic fibre for polymer composite to reduced environment burden. Hybrid sisal/glass fibre reinforced epoxy composites are prepared by hand lay-up technique using different weight fractions (10, 20, 30 and 40 %) with 10 mm length of fibres. Mechanical and water absorption properties of prepared composites are investigated. This study shows that the addition of glass fibre into sisal fibre reinforced composite has increased its mechanical properties. Statistical analysis is also carried out using T-test and ANOVA and found significant variation among composites
An intervention to improve the knowledge of anganwadi workers pertaining to growth monitoring in rural areas of Varanasi district, India
Background: Growth monitoring is one of the important functions of anganwadi workers (AWWs), for which they should have sufficient knowledge and training. With this background it was hypothesized that educational intervention can make a difference in the level of knowledge of AWWs in regard to growth monitoring. The main objective of the study was to evaluate the changes in knowledge of Anganwadi workers regarding growth monitoring through knowledge up-gradation training.Methodology: It was a field based interventional study, which was conducted on 66 AWWs each from Chiraigaon (intervention) and Cholapur (control) blocks of Varanasi district. The primary tool in this study was a pre-designed and pretested interview schedule for collecting information’s pertaining to study objective.Results: The mean score of knowledge was around 19.7 (max. Score was 30) in both the blocks during baseline survey and almost all the AWWs were having either average or good knowledge of growth monitoring. Post intervention a significant (p<0.01) difference has been observed between the mean knowledge scores of AWWs in intervention (25.32±2.44) and control (20.35±2.70) blocks and as much as 48.5% of AWWs were having excellent knowledge about growth monitoring in Chiraigaon block (p<0.01), while the situation was unchanged in Cholapur block.Conclusion: The knowledge up-gradation was found effective in improving the knowledge status of AWWs with regard to growth monitoring.
Aerosol Chemistry over a High Altitude Station at Northeastern Himalayas, India
BACKGROUND: There is an urgent need for an improved understanding of the sources, distributions and properties of atmospheric aerosol in order to control the atmospheric pollution over northeastern Himalayas where rising anthropogenic interferences from rapid urbanization and development is becoming an increasing concern. METHODOLOGY/PRINCIPAL FINDINGS: An extensive aerosol sampling program was conducted in Darjeeling (altitude approximately 2200 meter above sea level (masl), latitude 27 degrees 01'N and longitude 88 degrees 15'E), a high altitude station in northeastern Himalayas, during January-December 2005. Samples were collected using a respirable dust sampler and a fine dust sampler simultaneously. Ion chromatograph was used to analyze the water soluble ionic species of aerosol. The average concentrations of fine and coarse mode aerosol were found to be 29.5+/-20.8 microg m(-3) and 19.6+/-11.1 microg m(-3) respectively. Fine mode aerosol dominated during dry seasons and coarse mode aerosol dominated during monsoon. Nitrate existed as NH(4)NO(3) in fine mode aerosol during winter and as NaNO(3) in coarse mode aerosol during monsoon. Gas phase photochemical oxidation of SO(2) during premonsoon and aqueous phase oxidation during winter and postmonsoon were the major pathways for the formation of SO(4)(2-) in the atmosphere. Long range transport of dust aerosol from arid regions of western India was observed during premonsoon. The acidity of fine mode aerosol was higher in dry seasons compared to monsoon whereas the coarse mode acidity was higher in monsoon compared to dry seasons. Biomass burning, vehicular emissions and dust particles were the major types of aerosol from local and continental regions whereas sea salt particles were the major types of aerosol from marine source regions. CONCLUSIONS/SIGNIFICANCE: The year-long data presented in this paper provide substantial improvements to the heretofore poor knowledge regarding aerosol chemistry over northeastern Himalayas, and should be useful to policy makers in making control strategies
Identification of RAPD and SCAR markers associated with yield traits in the Indian tropical tasar silkworm Antheraea mylitta drury
Abstract The tropical tasar silkworm, Antheraea mylitta, is a semi-domesticated vanya silk-producing insect of high economic importance. To date, no molecular marker associated with cocoon and shell weights has been identified in this species. In this report, we identified a randomly amplified polymorphic DNA (RAPD) marker and examined its inheritance, and also developed a stable diagnostic sequence-characterized amplified region (SCAR) marker. Silkworms were divided into groups with high (HCSW) and low (LCSW) cocoon and shell weights, and the F 2 progeny of a cross between these two groups were obtained. DNA from these silkworms was screened by PCR using 34 random primers and the resulting RAPD fragments were used for cluster analysis and discriminant function analysis (DFA). The clustering pattern in a UPGMA-based dendogram and DFA clearly distinguished the HCSW and LCSW groups. Multiple regression analysis identified five markers associated with cocoon and shell weights. The marker OPW16 905 bp showed the most significant association with cocoon and shell weights, and its inheritance was confirmed in F 2 progeny. Cloning and sequencing of this 905 bp fragment showed 88% identity between its 134 nucleotides and the Bmc-1/Yamato-like retroposon of A. mylitta. This marker was further converted into a diagnostic SCAR marker (SCOPW 16 826 bp ). The SCAR marker developed here may be useful in identifying the right parental stock of tasar silkworms for high cocoon and shell weights in breeding programs designed to enhance the productivity of tasar silk
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