W K B Solutions
Mostrando 1-12 de 13 artigos, teses e dissertações.
-
1. W.K.B. Solutions for the Calculation of Field Intensity in the lower Ionosphere / Soluções W.K.B. para o cálculo da intensidade de campo na baixa ionosfera
Este trabalho apresenta métodos de cálculo aproximado do campo de uma onda se propagando na ionosfera. A ionosfera é um dos meios mais complexos quando se deseja calcular a intensidade de campo de uma onda eletromagnética, porque ela possui uma densidade eletrônica que varia com as estações do ano, e principalmente com a hora do dia. Outra dificuldade
Publicado em: 2007
-
2. Estudo de monocromadores assimetricos de raios-X
Asymmetric X-ray monochromators, firsts introduced by I. Fankuchen ( 1937 ) with the purpose of concentrating an X-ray beam have been the subject of numerous investigations. Evans, Hirsch and Kellar as early as 1948, based ther well known and hitherto unchallenged study on the hypothetic existence of a non-ref1ecting surface layer with an absorption coeffici
Publicado em: 1979
-
3. Potassium Channels in Chara corallina1: CONTROL AND INTERACTION WITH THE ELECTROGENIC H+ PUMP
Plasmalemma electrical properties were used to investigate K+ transport and its control in internodal cells of Chara corallina Klein ex Willd., em R.D.W. Cell exposure to solutions containing 10 mm KCl caused the potential, normally −250 millivolts (average), to depolarize in two steps. The first step was a 21 millivolt depolarization that lasted from 1 to
-
4. Effect of Bacteria and Amoebae on Rhizosphere Phosphatase Activity
The contributions of various components of soil microflora and microfauna to rhizosphere phosphatase activity were determined with hydroponic cultures. Three treatments were employed: (i) plants alone (Bouteloua gracilis (H.B.K.) Lag. ex Steud.) (ii) plants plus bacteria (Pseudomonas sp.), and (iii) plants plus bacteria plus amoebae (Acanthamoeba sp.). No al
-
5. Electrophysiological properties of ependymal cells (radial glia) in dorsal cortex of the turtle, Pseudemys scripta.
1. We have investigated the electrophysiological properties of ependymal cells in the isolated dorsal cortex of the turtle, Pseudemys scripta. The cell bodies of these radial glia form an epithelium at the ventricular surface, and each cell sends one or more branching processes through the cortex to the pial surface. Very few non-ependymal glia exist in the
-
6. X-ray diffraction studies of fibers and crystals of deoxygenated sickle cell hemoglobin.
Paracrystalline fibers of deoxygenated sickle hemoglobin in erythrocytes or concentrated solutions exhibit a phase transformation to a fully crystalline state. X-ray diffraction patterns of the fiber and crystallites are similar except in two respects: the equatorial spacings of the fibers suggest that they pack into a square lattice with a = 220 A, whereas
-
7. Ribosomal Ribonucleic Acid-Adenine (N6-) Methylase of Escherichia coli Strain B: Ionic and Substrate Site Requirements
These investigations are concerned with the ionic and substrate-site requirements of ribosomal ribonucleic acid (rRNA)-adenine (N6-) methylase of Escherichia coli B. The methylase was essentially inactive in solutions of low ionic strength. The addition of MgCl2 (optimal at 5 mM) or; to a lesser degree, KCl (optimal at 45 mM) stimulated the rate of methylati
-
8. Analysis of the high mobility group proteins associated with salt-soluble nucleosomes.
Two methods have recently been described for the isolation of monomer nucleosomes enriched in transcribed sequences which depend on their solubility in 0.1 M NaCl (Levy, W.B. and Dixon (1978), Nucleic Acid Res., 5, 4155-4163) or solutions containing divalent metal ions (Bloom, K.S. and Anderson, J.N. (1978), Cell, 15, 141-150). Using these procedures the pro
-
9. Single-molecule fluorescence detection: autocorrelation criterion and experimental realization with phycoerythrin.
A theory for single-molecule fluorescence detection is developed and then used to analyze data from subpicomolar solutions of B-phycoerythrin (PE). The distribution of detected counts is the convolution of a Poissonian continuous background with bursts arising from the passage of individual fluorophores through the focused laser beam. The autocorrelation fun
-
10. Heat production in chemically skinned smooth muscle of guinea-pig taenia coli.
1. The rate of heat production of chemically skinned guinea-pig taenia coli smooth muscle at 25 degrees C was measured using microcalorimetric techniques. 2. Muscle strips were mounted isometrically and incubated in solutions containing MgATP (3.2 mM) and phosphocreatine (PCr, 12 mM), pH 6.9. Activation was obtained by the injection of Ca2+ into the sample c
-
11. Crystalline cytochrome c oxidase of bovine heart mitochondrial membrane: composition and x-ray diffraction studies.
The integral mitochondrial membrane protein cytochrome c oxidase (ferrocytochrome-c:oxygen oxidoreductase, EC 1.9.3.1) was crystallized from solutions of the protein from bovine heart isolated as described earlier [Yoshikawa, S. & Caughey, W. S. (1982) J. Biol. Chem. 257, 412-420]. Crystallinity was demonstrated by x-ray diffraction. Microcrystals (tetragona
-
12. Slow inward tail currents in rabbit cardiac cells.
1. A whole-cell gigaseal suction microelectrode voltage-clamp technique has been used to study slow inward tail currents in single myocytes obtained by enzymatic dispersion of rabbit ventricle and atrium. A variety of stimulation protocols, Tyrode solutions and pharmacological agents have been used to test three hypotheses: (a) that the slow inward tail curr