backfire helical feed

a novel backfire helical feed for a paraboloidal reflector is described. the antenna requirements were a 20 percent bandwidth at l-band, right-hand circular polarization, a maximum voltage standing-wave ratio (vswr) of 2. 0, and a peak power capability of 200 kw unpressurized. the feed consists basically of a 3. 5-turn helix wound around ..

investigation of integral parameter $gamma$ for media containing large particles

to solve inverse scattering problems on the bais of the theory of g. r. rozenberg, it is necessary to know the connection between the constant $gamma$ and the structure parameters of the medium an experimental study of the integral parameter is presented here the objects investigated were textile materials $left bracket$ e. g , cloth of n..

parathion effects on reproductive characteristics and vital organ weights of female cottontail rabbits (sylvilagus floridanus)

because some wildlife species rely on high net reproductive rates to maintain populations, decreases in any aspect of reproduction may more adversely affect population levels than losses of individual adults. the studies reported in this paper were initiated to determine the effects of parathion on a prolific wildlife species, the cottont..

radiation pre-treatments of cellulose materials for the enhancement of enzymatic hydrolysis - i: pure cotton

the effect of $gamma$ -ray pre-irradiation of cotton cellulose on glucose production on enzymatic hydrolysis by cellulase has been investigated. pure cotton has been irradiated in air, in water and in acetate buffer solution over the dose range 10**3-10**6 gy pre-irradiation in water or in acetate buffer solution is more effective than in..

electron diffraction study of $alpha$ -chitin

chitin is a naturally occurring polysaccharide, the monomeric unit of which is n-acetyl d-glucosamine. this polysaccharide exists in three crystalline polymorphic forms, viz. , $alpha$ -, $beta$ -, and $gamma$ -chitins. the structure of chitin has been determined by various investigators using the x-ray diffraction technique recently, bla..

immobilised cellulolytic and hemicellulolytic enzymes from macrophomina phaseolina

cellulolytic enzymes from macrophomina phaseolina were immobilized in acrylamide polymer. the immobilized enzyme preparation showed activity towards filter paper and cotton however, the degree of hydrolysis of highly organized cellulose, particularly cotton, appears to be low in comparison with that of soluble substrate. the kinetic studi..

adsorption of anionic surfactants on cotton

in the reported experiment, the authors investigated the adsorption mechanism of anionic surfactants and their mixtures on cotton fabric, especially with regard to the effect of temperature the observed phenomena are found to be due to changes in the micellization process of the surfactants and can be accounted for by the effect of water ..

cotton textile effluent waste as a possible source for chemical treatment of straws and stovers

the usefulness of the effluent wastes was studied in place of sodium hydroxide treatment for improving the nutritive value of wheat and paddy straws or maize stovers in ruminant feeding. kier boiling waste (kbw) and mercerization washing (mww) had 0. 85 and 0. 29 titrable alkalinity, whereas bleaching washing waste (bww) was neutral in re..

comparative energy costs of stem cuttings, seedlings and seeds as propagules in woody biomass plantations

estimation of the energy required to produce stem cuttings of eastern cottonwood (populus deltoides bartr. ) was made. these costs ranged from 0. 592mj to 0. 803mj per cutting. the energy required for production of seeds was found to be 0. 18 and 0. 79 of the energy required to produce stem cuttings and 1-0 seedlings, respectively. also, ..

crystal and molecular structure of neodymium(iii) trinitratotris $left bracket$ tris(dimethylamino)phosphine oxide $right bracket$

the crystal structure was determined of the neodymium compound with the composition. two crystallographically different neodymium complexes with the identical composition were detected in the independent portion of the elementary cell. coordination number of neodymium atoms in both molecules is equal to 9. coordination polyhedron (cp) was..