structural control of jurassic sedimentation in alabama and florida

the extent and thickness of jurassic strata in alabama and florida were mapped as part of a u. s. geological survey regional geohydrologic study. rocks equivalent to the werner, louann, norphlet, smackover, haynesville, and cotton valley sequences of mississippi and arkansas have been recognized and, except for the werner equivalent, are ..

influence of homovalent impurities on the residual resistivity of metals

experimental values of $delta$ p/c, where c $yields$ 0, were obtained for 71 matrix-homovalent impurity pairs. if both metals have a cubic lattice there is little or no change when impurity and matrix exchange places. lattice strain is not the decisive factor, but it may be differences in the ion screening of matrix and impurity. 45 refs

decontamination of cotton tissues from some radioactive elements

cotton consists of cellulose fibers which have an effective adsorrption surface. decontamination, of short-lived radioactive isotopes from cotton tissues and clothes is usually done by storage till the activity has fallen to a safe level. in cases of contamination by long-lived radioisotopes, washing and rinsing different times with water..

tight gas sands - permeability, pore structure, and clay

gas permeability has been measured on a suite of cores from the spirit river tight gas sand of western alberta and on two samples from the cotton valley formation of east texas. using nitrogen as the mobile fluid, the author has measured permeability as a function of partial water saturation at in-situ levels of pore pressure and confinin..

auswirkung der zinn-blei-plattierung beim nachschmelzen $left bracket$ effect of tin-lead plating in the remelting process $right bracket$

problems associated with flow melting of tin-lead coatings involved in the manufacture of printed-circuit boards are considered in particular, the remelting process in conjunction with plating is discussed. the importance of careful purification and preparation prior to putting the p/c boards into a (chemical) both is pointed out. instrum..

das heissluftverzinnen im horizontalen durchlauf. $left bracket$ hot-air soldering in horizontal passage $right bracket$

the method of hot-air soldering, which is widely used in the production of printed-circuit boards is described. it deviates from conventional technology, where p/c boards are dipped vertically, by passing the boards horizontally. a considerable number of such $left double quote$ solder coater levelers $right double quote$ are already in u..

fluoroaromatic ethers of cotton

the reactions of cotton with pentafluorobenzoic acid and pentafluorobenzamide under basic conditions to yield 4-substituted terafluorophenyl ethers of cellulose are described. decarboxylation of the carboxy tetrafluorophenyl cellulose to give 2,3,5, 6-tetrafluorophenyl cellulose also has been accomplished. properties of these cellulose de..

technologia metalizacji plytek drukowanych. $left bracket$ metallization technology of printed circuit boards $right bracket$

electroless plating and electroplating used in poland in the manufacture of printed boards are described. research, development and implementation works is reported. in polish

studies on poly(ethylene terephthalate)/cotton blends by differential scanning calorimetry

differential scanning calorimeter curves of polyester/cotton blends indicate that the glass transition temperature, t//g, of cotton varies with the blend composition. standard curves for quality control purposes are presented and are based on either the cotton or poly(ethylene terephthalate) transition peak areas factors that contribute t..

sichtpruefungen bei der fertigung bestueckter leiterplatten $left bracket$ visual tests for the production of mounted printed circuit boards $right bracket$

the use of visual test methods during the manufacturing process of p/c boards is discussed, particularly from the economic and operational points of view. a failure limiting factor is derived, below which visual inspection is not permissible. 13 refs. in german