synthesis and properties of graft copolymers of cotton cellulose with fluoroethylenes in presence of ce**4u $plus$

chemical graft polymerization of some fluoromonomers on cotton cellulose has been investigated in presence of a redox system containing tetravalent cerium. physical chemical methods have been used to study structural features of graft copolymers of cotton cellulose with fluorine-containing polymers. it is assumed that the grafting process..

economic optimization of furrow irrigation with uniform and nonuniform soil

a furrow irrigation system is economically optimized for maximum profit on both uniform and nonuniform soil. flow rate and cutoff time are design (decision) variables and a volume balance hydraulic model simulates irrigation on both soils. optimum flow rate is higher, cutoff time is shorter and profit is less under nonuniform soil conditi..

influence of depth and spacing of tile drains on crop productivity in nile delta

an agricultural drainage experiment with the tile drains installed at lateral spacings of 12. 5, 25 and 50 m and drain depth of 1. 2 and 1. 5 m was initiated in egypt in 1976 to examine long-term effects of drainage on crop production. the experimental fields were planted to cotton, clover, rice and wheat in rotation data from the three c..

polymer communications: uniform star polymers of daoud and cotton: an appraisal

the principal geometrical properties of uniform self-avoiding star polymers are determined in the iterative convolution (ic) approximation. the predictions are found to be in good agreement with monte carlo (mc) simulations. neither the ic nor the mc analysis appears to support the scaling predictions of m. daoud and j. p. cotton. instead..

shrinkage curve indices to quantify cultivation effects on soil structure of a vertisol

differences in selected parameters and derived variables of models fitted to soil shrinkage curves were used to investigate soil structural degradation of an irrigated pellustert in northern new south wales, australia. significant differences between clods taken from the same depths in land prepared for cotton (gossypium hirsutum l. ) whe..

crop-water production functions for sweet corn and cotton irrigated with saline waters

the effect of irrigation water quality (salinity) and quantity on the yields of sweet corn (zea mays cv. jubilee) and cotton (gossypium hirsutum l. cv. acala sj-2) was studied in a sandy loam (typic torrifluvent) soil. for each of the irrigation water salinities of c//o $equals$ 1. 8, 3. 6 and 6. 7 ds/m (for corn) and c//o $equals$ 3. 6, ..

new equation for seal users

the development of newer and more efficient techniques for sealing mechanical equipment against a variety of liquid, gaseous and granular media, has been rapid and continuous. for many years the standard materials available to users of packed glands were asbestos and various types of common organic fibers, such as ramie, flax, jute and co..

structural modification of various forms of cellulose by nitric acid solutions

an attempt is made to characterize more completely the different forms of cellulose modified by hno//3 solutions. it is shown that washing the hno//3-swollen cellulose with glacial ch//3cooh removes the excess hno//3 which does not take part in the formation of knecht's compound. these results confirm the hypothesis put forth by k. hess a..

investigation of the ignition and combustion of loosely compacted commercial steel wool

the ignition and combustion characteristics of loosely compacted commercial steel wool samples when introduced promptly into low velocity heated air streams and the morphology of the quenched residues were invetigated. the effects of the important factors of sample compactness, stream temperature and velocity, and exposure time were estab..

rigged for silent running

whenever a streamer of hydrophones is towed in the sea, acoustic noise is generated. in recent years, the noise levels on seismic streamers have been an issue of growing concern for both the manufacturers and users. this article discusses a new fiber optic seismic streamer which meets the need for better data quality, shorter hydrophone g..