Ground and flight test results for standard VOR and double parasitic loop counterpoise antennas

Results of ground and flight tests carried out at 109 MHz to study the vertical plane radiation patterns of standard VOR and double parasitic loop counterpoise antennas above ground are discussed. The ground tests consist of the measurement of the fields produced in the quasi-radiation zone of the test antenna The flight tests consist of measuring the far field with the help of an aircraft flying at a constant altitude along chosen radial paths to and from the test antenna. The reduced test results are compared with available theoretical values.     

High Accuracy Compact Schemes and Gibbs' Phenomenon

Compact difference schemes have been investigated for their ability to capture discontinuities. A new proposed scheme (Sengupta, Ganerwal and De (2003). J. Comp. Phys. 192(2), 677.) is compared with another from the literature Zhong (1998). J. Comp. Phys. 144, 622 that was developed for hypersonic transitional flows for their property related to spectral resolution and numerical stability. Solution of the linear convection equation is obtained that requires capturing discontinuities. We have also studied the performance of the new scheme in capturing discontinuous solution for the Burgers equation. A very simple but an effective method is proposed here in early diagnosis for evanescent discontinuities. At the discontinuity, we switch to a third order one-sided stencil, thereby retaining the high accuracy of solution. This produces solution with vastly reduced Gibbs' phenomenon of the solution. The essential causes behind Gibbs' phenomenon is also explained.     

The triglyceride composition of Hibiscus esculentus seed oil

The fatty acid composition of Hibiscus esculentus seed oil was determined by spectrophotometry and gas-liquid chromatography. The percentages of individual acids were found to be: myristic, 0.2; palmitic, 30.2; stearic, 4.0; palmitoleic, 0.4; oleic, 24.4 and linoleic, 40.8. Triglyceride composition was calculated from the fatty acid compositions of the native oil and of the monoglycerides produced from it by pancreatic lipase hydrolysis. The oil is composed of 1.8, 27.7, 48.1 and 22.4% GS₃, GS₂U, GSU₂ and GU₃, respectively.     

First fifteen amino acid residues in buffalo alpha S 1-casein from the N-terminal end

Conventional Edman degradation techniques with phenyl isothiocyanate and p-phenylazophenyl isothiocyanate were used to determine the first 15 amino-terminal amino acid residues in buffalo alpha S 1-casein. The results were compared to those of bovine alpha S 1-casein.     

Computation of leading-edge contamination

The leading-edge contamination (LEC) problem of an infinite-swept wing is computed by solving the full two-dimensional Navier-Stokes equation using a very high spectral accuracy compact scheme. The initial condition is given by the steady attachment-line boundary layer forming over the leading-edge of an infinite swept wing or a yawed cylinder. The contamination is shown as due to either a convecting or a stationary vortex far outside the attachment-line boundary layer at the leading edge. This mechanism is proposed to account for the sub-critical instability onset observed for attachment-line boundary layer. (The criticality is for Reynolds number (based on momentum thickness) exceeding 100--an empirically suggested value based on earlier experiments.) The presented results show the problem to be essentially two-dimensional. Inflow and outflow of computational domain are chosen so that we consider cases of both sub- and super-critical instabilities. The receptivity mechanism of leading-edge contamination for both cases is investigated with respect to different parameters. Finally, we have also analyzed the computed solutions by proper orthogonal decomposition (POD) to highlight the low-dimensional nature and to provide a quantitative measure of leading-edge contamination events.     

Magneto-visco-elastic surface waves in stressed conducting media

The present paper is concerned with magneto-visco-elastic surface waves in conducting media involving time rate of strain and stress of first order, the media being under an initial stress of hydrostatic tension or compression. The theory of magneto-visco-elastic surface waves in a conducting medium involving time rate of strain and stress of first order is derived under an initial stress. The above general theory is then employed to characterise Rayleigh, Love and Stoneley waves. Results obtained in the above cases reduce to well-known classical results when viscosity and magnetic field are absent.     

Possible role of glutathione in resistance to heavy metals and hydrogen peroxide in a radioresistant Chinese hamster V79 cell strain

To understand the cellular and biochemical nature of radioresistance in the strain M5 derived from Chinese hamster V79 cells, the sensitivity of the resistant cells towards CdCl2, Zn(Ac)2, and H2O2 by the colony forming ability has been tested. D0 values for these compounds in Chinese hamster V79 cells were 5.4 microM, 27.8 microM and 4.3 micrograms/ml respectively while for M5 cells these were 8.3 microM, 142.9 microM and 11.9 micrograms/ml respectively. The resistance to heavy metals as well as the oxidative damage could be reversed by the inhibition of glutathione synthesis by the drug buthionine sulfoximine (BSO). These set of data indicate that the cellular antioxidant glutathione plays an important role in the observed oxidant-resistant phenotype as well as heavy metal resistance in M5 cells.     

Chemical Investigations of the Sapindus mukorossi Seed Oil

Two lipid fractions ‘A’ and ‘B’ were isolated from Sapindus mukorossi seed oil by preparative TLC. Fraction ‘A’ (70.4%, R_f value 0.76) is a normal triglyceride and its fatty acid compositions was determined by GLC. Fraction ‘B’ (29.6%, R_f value 0.51) shows the presence of nitrogenous constituents. It develops a reddish brown colour in contact with alkali or alkoxide solution. Percentages of individual acids present in fraction ‘A’ were found to be: palmitic, 5.5; stearic, 3.2; oleic, 64.6; linoleic, 2.9; arachidic, 3.1; eicosenoic, 20.1; minor acids, 0.6. Fraction ‘A’ is composed of 0.1,3.6,29.9 and 66.4 percent trisaturated, monounsaturated-disaturated, diunsaturated-monosaturated and triunsaturated glycerides respectively. On GLC analysis, the percentages of individual acids constituting fraction ‘B’ were found to be:palmitic, 3.8; stearic, 1.5; oleic, 33.6; linoleic, 2.9; arachidic, 11.1; eicosenoic, 30.2; behenic, 2.8; docosenoic, 1.4 and two unidentified acids 7.3 and 5.4. Fraction ‘B’ responded to hydrolysis by pancreatic lipase and the product with polarity equivalent to that of 2-mono-glyceride was isolated by TLC and converted to methyl ester. Percentages of individual acids constituting that methyl esters were found to be:palmitic, 11.8; stearic, 4.1; oleic, 12.8; linoleic, 3.7; arachidic, 8.3; eicosenoic, 10.2; behenic, 6.5; docosenoic, 4.2; and two unidentified acids 22.2 and 16.2. This non-glyceridic component of the S. mukorossi seed oil is a cyanolipid, 1-cyano-2-hydroxymethyl prop-1-ene-3-ol. The structure was confirmed by I. R., N.M.R. and Mass spectral-analysis.     

Sunrise and sunset effects as observed on microwave propagation over a line-of-sight path

Microwave signal propagation provides an effective measure of studying the variable nature of the atmosphere. Sunrise and sunset periods are characterized by the dissolution and formation of nighttime temperature inversions. Signal amplitude recordings at 6.7 GHz over DumDum-Andul line-of-sight (LOS) communication link during post-sunrise period are characterized by the appearance of an enhancement in signal strength (as high as 20 dB). The sunset effect or the evening transition is observed as an enhancement in signal amplitude of about 10- 12 dB over the link. The signal characteristics observed during transition periods over the 6.7 GHz DumDum-Andul link are studied herein.