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Activation Energy for Ion Movement in Thin Water Films on Montmorillonite 全文
1963
Oster, James D. | Low, Philip F.
Desorption isotherms were determined for Li-, Na- and K- montmorillonite at several temperatures. Relative partial molar entropies of the adsorbed water were calculated from these isotherms. The specific conductance of each clay was determined as a function of temperature at water contents corresponding to one layer, two layers and several layers of adsorbed water. Also, the d₀₀₁ spacings were determined at the two lower water contents by X-ray analysis. For the determination of specific conductance, the clays were packed into porous glass conductance cells which allowed them to equilibrate with an atmosphere of controlled relative humidity. The relative humidity was changed with the temperature in order to maintain the desired water content. Then the specific conductance of each clay was plotted against the reciprocal of the absolute temperature to obtain the activation energy for the movement of the adsorbed ion. The resulting activation energies were interpreted in terms of ion-oxygen interaction at the mineral surfaces and in terms of the orderliness of the adsorbed water as indicated by the entropy data.
显示更多 [+] 显示较少 [-]Occurrence of 2-hydroxy fatty acids in animal tissues* 全文
1963
Yasuo Kishimoto | Norman S. Radin
The contents of 2-hydroxy fatty acids in rat spleen, kidney, lung, sciatic nerve, and skin, and in bovine plasma, were determined by a copper precipitation method, and the proportions of the various hydroxy acids were determined by gas-liquid chromatography. It was observed that there are two groups of hydroxy acids, short chain (16h:0 as major component) and long chain (24h:0 as major component). The relative proportions of the two groups varied with the tissue. No 2-hydroxy acids could be found in liver and epididymal fat. The 2-hydroxy acids of brain are not liberated by mild alkali and therefore occur only in amide linkage. The amide-bound fatty acids of brain gangliosides and sphingomyelin account for none, or only a very small fraction, of the total brain hydrosy acids.
显示更多 [+] 显示较少 [-]Ovine ketosis. IV. The effect of alloxan on the ketone body and blood sugar levels of Merino wethers 全文
1963
It has been previously shown that the administration of alloxan leads to the destruction of the islets of Langerhans in the pancreas (Dunn, Sheehan & McLetchie, 1943) with a subsequent development of a true diabetic condition which results in a simultaneous increase of both blood sugar and ketone body levels. A small number of workers have previously studied this condition in ruminants. Jarrett (1946) administered alloxan intravenously to sheep in doses varying from 90 to 200 mg per Kg body weight. Only blood sugar values were determined and these rose to levels of 230, 250 and 310 mg per cent in three of the animals which survived for a long period (14, 47 and 53 days respectively). McCandless, Woodward & Dye (1948) also administered alloxan to sheep in doses varying from 75 to 125 mg per Kg. The blood sugar and ketone body values, obtained sporadically during a ten day period, ranged from 146 to 218 mg per cent for the former and 11 to 51 mg per cent for the latter. Survival times varied, ranging from only 85 hours to 157 days. Schultz & Smith (1951) dosed one goat with 90 mg of alloxan per Kg. As a result the ketone body and blood sugar levels rose to 60 and 200 mg per cent respectively and the animal survived for 14 days. Finally Goetsch (1957) administered 100 mg of alloxan per Kg to non-pregnant ewes. In this instance blood sugar and ketone body levels were determined only at 24 and 48 hours after the dosing of the drug. During this period the former were found to rise on an average to a maximum of 260 mg per cent and the latter to one of 4 • 9 mg per cent. In the present experiment the animals were dosed with approximately 50 mg of alloxan per Kg and both blood sugar and ketone body levels determined. In addition the latter were partitioned into their individual fractions.
显示更多 [+] 显示较少 [-]Chemical Composition of Kentucky Bluegrass (Poa pratensis) as a Function of Applied Nitrogen, Phosphorus, and Potassium 全文
1963
Walker, William M. | Pesek, John
SynopsisThe mean percentages of N, P, and K in clippings were determined and expressed as functions of the applied fertilizer by multiple regression methods. The coefficients of determination for the 3 functions were all above 0.97, indicating that quadratic functions with linear ✕ linear interactions served to express the relationships well.
显示更多 [+] 显示较少 [-]Phosphorus Uptake and Soil Tests as Related to Forms of Phosphorus in Some Michigan Soils 全文
1963
Susuki, A. | Lawton, K. | Doll, E. C.
Truog P, Bray P, Olsen P, resin P, and surface P were all determined on samples of 17 surface soils from Michigan (from 5 great soil groups), and each soil was cropped in the greenhouse with barley for 4 weeks to determine P uptake and A values. Ca-P, Al-P, Fe-P (by the Chang and Jackson procedure), and organic P were determined on 10 of these soils. Correlation analyses indicate that short-term uptake of P by barley in the greenhouse was highly correlated with Truog P, while A values, which may be more indicative of seasonal availability, were most highly correlated with Olsen, resin, and Bray P. Organic P and Fe-P did not contribute to the P removed by any of the measurements. Truog P apparently removed portions of both the Ca-P and Al-P fractions, and P removed by cropping was also derived from these two fractions. All the other measurements were highly correlated with only Al-P.
显示更多 [+] 显示较少 [-]Investigation of the Relation between the Tensile Properties of Cotton Fiber Bundles and Yarns in the Dry and Wet States 全文
1963
Pillay, K. P. R.
Relationships existing between the tensile properties of cotton fiber bundles and yarns under two ambient conditions,(i) in standard atmosphere and (ii) in the wet state have been studied on 27 cottons varying widely in fiber properties. The cottons have been processed into 24s (24.6 tex) yarn with twist multipliers ranging from 3.75 to 6.0 Correlations between the elastic properties of fibers on the one hand and corresponding yarn properties on the other have been determined for different twist multipliers The combined influence of six fiber properties on yarn strength, elongation, stiffness, and toughness at twists for maximum strength and the order of importance of fiber properties have also been determined by multiple correlation analysis. It is shown that cottons vary widely in their response to wetting, and the elastic properties of single yarns are significantly correlated with the corresponding yarn properties, the degree of association varying, however, with the twist in yarn and conditions of test. Multiple correlation coefficients in the wet state are lower than those in the dry state, indicating that wetting increases the importance of some fiber properties not included in the six investigated.
显示更多 [+] 显示较少 [-]Structural Properties of Cotton Fibers: Part II: Birefringence and Structural Reversals in Relation to Mechanical Properties 全文
1963
Betrabet, S. M. | Pillay, K. P. R. | Iyengar, R. L. N.
Birefringence and structural reversals have been determined on 20 Indian cottons and correlated with their mechanical properties. The variation in spiral angles among cottons is influenced by the variation in convolution angle, and Meredith's observation that average spiral angle in the original unconvoluted fibers may be the same for all the varieties is supported by the results obtained. Specieswise distribution of structural reversals was determined by a simple, quick method. Deshi² cottons have very few reversals as against cottons belonging to the G. hirsutum and G. barbadense species. Hence, the distribution of reversals appears to be a genetic characteristic and it would be worth investigating whether Wakeham and Spicer's observation of preferential breakage at points of reversals holds good for deshi cottons. The average distance between reversals is found to be highly correlated with the cotangent of the spiral angle at constant cell width just as in the case of wood tracheids and bamboo fibers, observed by Meredith; the peculiar behavior of G. arboreum indicum cottons in this regard has been pointed out. The manner in which the varieties of cottons selected for investigation influence the trend of the results is indicated.
显示更多 [+] 显示较少 [-]Brackish Water Irrigation of Several Vegetable Crops in Humid Regions 全文
1963
Gallatin, M. H. | Lunin, J. | Batchelder, A. R.
SynopsisThe use of brackish water over a 5-year period indicates that salinity effects are determined by variations in the saline status of the soil throughout the growing season and by the sensitivity of the specific crop, especially with respect to the growth stage at which salinized. Rainfall distribution is an important factor influencing salt accumulation in the soil.
显示更多 [+] 显示较少 [-]Assessing the Utility of Pan Evaporstion for Controlling Irrigation of Sugar Cane in Hawaii 全文
1963
Robinson, F. E. | Campbell, R. B. | Chang, Jen-hu
SynopsisThe timing of irrigation applications was determined with reference to the net evaporation from a U.S. Weather Bureau pan. Maximum sugar yields were obtained when 2.5 inches of irrigation water were applied after 2.9 inches had evaporated from the pan. When adjusted to a constant population, the differences in yields of 6 irrigation-interval treatments reflected differences in stalk length. Decrease in stalk length resulted from soil moisture tensions which exceeded 2 bars.
显示更多 [+] 显示较少 [-]Contribution to the Study of the B–L Curve of Cotton Yarns 全文
1963
Balasubramanian, N.
For the worsted system of processing Grosberg [9] has developed an equation which makes possible the derivation of the variance–length curve of a yarn from the total variance of each of the slivers made during the manufacture of the yarn. The present study is an attempt to evaluate the suitability of this equation for cotton processing. For this purpose, two cottons were spun to 40s and one to 30s using the orthodox system of processing consisting of 3 speed frame passages. The irregularity of the material at different stages of processing was determined with the Uster evenness tester, and the B–L curve of the yarn was deduced using Grosberg's equation. The actual B–L curve of the yarn was also determined with the evenness tester by the “inert test” method. On plotting the results it is found that there is considerable discrepancy between theory and experiment—the predicted curve is seen to be too high in every case. The reasons for this discrepancy are discussed. A preliminary study on two yarn samples showed that there is good agreement between the B–L curves obtained by the Uster evenness tester and the cut-and-weigh method. The log B (L)–log L plot is found to be fairly linear, except for short lengths, for cotton yarns.
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