400 research outputs found

    Biological assessment of water pollution: A study of the river Kapila

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    An attempt has been made to assess the feasibility of application of biological data to evaluate and monitor water pollution of the river Kapila, near Nanjangud, Karnataka. Two pollution index factors, one at the generic level and another at species level of the Algae, have been computed. Significant correlation between biological and some physico-chemical factors has been established. The theme that algae serve as tools of pollution and that their index scores at the species level is a more reliable parameter for the evaluation of water quality has been established. © 1984, Taylor & Francis Group, LLC. All rights reserved

    Study on Airborne Pollen in the Atmosphere of Bangalore City

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    The atmospheric pollen of Jnana Bharathi campus, Bangalore University was surveyed during one year period from January 2011 to December 2011 using a vertical cylinder trap. A total of 28 pollen types were identified, among which 7 were present throughout the year. These belonged to Poaceae, Tridax sp., Eucalyptus sp., Parthenium hysterophorus, Cocus nucifera, Croton sparsiflorus and Mimosa pudica. The most predominant Pollen was Parthenium hysterophorus (23.87%) followed by Poaceae (16.19%), Mimosa Pudica (11.31%), Delonix regia (8.77%) and Eucalyptus spp. (7.58%) were found in the atmosphere of Bangalore city. Maximum pollen concentration was observed in the month of May (880/m3) followed by April (552/m3) and minimum in June (163/m3). The total pollens as well as individual pollen types displayed distinct seasonal periodicity in their incidence. The present study will provide preliminary but useful data to the allergologists for effective diagnosis and treatment of local population suffering from pollen hypersensitivity

    SARAS 2: A Spectral Radiometer for probing Cosmic Dawn and the Epoch of Reionization through detection of the global 21 cm signal

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    The global 21 cm signal from Cosmic Dawn (CD) and the Epoch of Reionization (EoR), at redshifts z630z \sim 6-30, probes the nature of first sources of radiation as well as physics of the Inter-Galactic Medium (IGM). Given that the signal is predicted to be extremely weak, of wide fractional bandwidth, and lies in a frequency range that is dominated by Galactic and Extragalactic foregrounds as well as Radio Frequency Interference, detection of the signal is a daunting task. Critical to the experiment is the manner in which the sky signal is represented through the instrument. It is of utmost importance to design a system whose spectral bandpass and additive spurious can be well calibrated and any calibration residual does not mimic the signal. SARAS is an ongoing experiment that aims to detect the global 21 cm signal. Here we present the design philosophy of the SARAS 2 system and discuss its performance and limitations based on laboratory and field measurements. Laboratory tests with the antenna replaced with a variety of terminations, including a network model for the antenna impedance, show that the gain calibration and modeling of internal additives leave no residuals with Fourier amplitudes exceeding 2~mK, or residual Gaussians of 25 MHz width with amplitudes exceeding 2~mK. Thus, even accounting for reflection and radiation efficiency losses in the antenna, the SARAS~2 system is capable of detection of complex 21-cm profiles at the level predicted by currently favoured models for thermal baryon evolution.Comment: 44 pages, 17 figures; comments and suggestions are welcom

    Differential scanning calorimetry and wide-angle X-ray scattering studies of bread staling

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    Wide angle X-ray scattering (WAXS) was used to follow the development of crystal size and strain during the staling of bread containing different additives. In this it was observed that one can classify the good anti-staling additives as gelatin, propylene glycol, maltodextrin and anti-staling enzyme corresponding to the order of increasing crystal size for a particular Bragg reflection in all the samples and correlate using DSC (differential scanning calorimetry) studies of all the bread compositions containing different additives. (C) 1998 John Wiley & Sons, Inc

    The study of antiepileptic activity of clove oil in chemical induced convulsions in mice

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    Background: The objective was to evaluate and compare the effect of an extract of essential oil of clove with the standard sodium valproate on pentylenetetrazole (PTZ) induced seizures in animal models.Methods: A total of 30 mice were taken, they were given a chemo shock at the concentration of 60 mg/kg using PTZ. 30 mice were divided into 5 groups of 6 animals each the control group received distilled water 5 ml/kg i.p., standard received injection sodium valproate 200 mg/kg i.p. another group received sesame oil – 10 ml/kg i.p. (control), test groups received Clove oil - 0.075 ml/kg i.p., clove oil - 0.1 ml/kg i.p., respectively. All the injections were given 30 mins before the administration of PTZ.Results: Clove oil produced a significant antiepileptic effect at all the doses.Conclusion: Clove oil has shown significant antiepileptic activity in mice

    Anisotropy of Lorentz Field Factors in Two Symmetric Homologous Series

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    Generation of High Voltage DC using Diodes & Capacitors in Ladder Network

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    The project is designed& constructed to develop a high voltage DC of around 2KV from a input AC supply source of 230V using the capacitors and diodes that are constructed in the form of ladder network based on voltage multiplier concept. Generally transformers are used for stepping up of voltage in which the output of the secondary of the step up transformer increases the voltage and decreases the current. The other method for stepping up the voltage without the use of transformers is by using voltage multiplier circuit which converts AC to DC. These Voltage multipliers are primarily used to develop high voltages where low current is required. The concept of developing high voltage DC from single Phase AC is described in this project which can be enhanced up to 10KV. For safety purpose this project is restricted with a multiplication factor of 8 so that the output would be within 2KV.This concept of generation of high voltage using multiplier circuit is used in Electronic appliances such as CRT?s, oscilloscopes and in industrial applications. The principle of voltage multiplier circuit is that the voltage keeps on doubling at each stage. Thus, the output of an 8 stage voltage multiplier circuit is 2KV DC which cannot be measured by using a standard multimeter. Hence a potential divider of 10:1 is used at the output such that 200V reading means 2KV

    Response Spectrum Analysis of Printed Circuit Boards Subjected to Shock Loads

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    AbstractA spacecraft consists of a number of electronic packages to meet the functional requirements. An electronic package is generally an assembly of printed circuit boards placed in a mechanical housing. A number of electronic components are mounted on the printed circuit board (PCB). A spacecraft experiences various types of loads during its launch such as vibration, acoustic and shock loads. Prediction of response for printed circuit boards due to shock loads is important for mechanical design and reliability of electronic packages. The modeling and analysis of printed circuit boards is required for accurate prediction of response due to shock loads. The validated finite element model of the PCB can be adopted to perform response spectrum analysis. Shock response spectrum analysis of printed circuit boards subjected to a half-sine pulse excitation is carried out using finite element method. The objective of this paper is to predict the shock response spectrum of a printed circuit board due to launch environment. The analysis results are validated by conducting experimental tests of PCB

    Crystallite shape, dielectric constant and functional data analysis of various cotton fibres using WAXS data

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    Four different varieties of cotton fibres have been used for X-ray diffraction study using in-house programs. X-ray datahave been corrected for instrumental broadening and Lorentz polarization factors before using them for further analysis.Using Peakfit® program, 13-15 Bragg reflections are identified and cell parameters are determined by CHECKCELL®. Fullwidth at half maxima (FWHM) of these reflections are used to estimate the crystallite size and strain along [hkl] directions.Using these results and employing a novel method, a 3-dimensional image of the crystallite shapes in these cotton fibres arecomputed. Employing Lorenz-Mie theory of scattering of electromagnetic radiation by molecules embedded in dielectricspheres, the dielectric constant of cellulose along amorphous region has been computed. This technique can be extended toany material of interest. Correlation among varieties of fibres and each physical parameter like crystallite size, strain,tenacity and staple length have been investigated using functional analysis, which shows the correlation between physicalparameters with varieties of cotton fibres
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