خيارات البحث
النتائج 1 - 10 من 63
The Determination of Available Sulfur in Soils النص الكامل
1960
Kilmer, Victor J. | Nearpass, D. C.
A laboratory procedure was sought which would determine available sulfur in soils. As finally evolved, the method consists of extracting the sulfur with 0.5M NaHCO₃ at pH 8.5 and determining sulfur in the extract by the Johnson-Nishita procedure. Sulfur determined in this manner correlated very well with sulfur “A” values, an “r” value of 0.89 being obtained for 30 surface soils. Soils having < 10 ppm. S as determined by the proposed procedure generally responded to applications of sulfur.
اظهر المزيد [+] اقل [-]Technical notes. Mites associated with honeybees in Queensland النص الكامل
1960
Brimblecombe, A.R. | Roff, C.
In Queensland, casual infestations of honeybees, Apis mellifera L., by mites, Pediculoides ventricosus Newp. (now known as Pyemotes ventricosus (Newp.)) and Hypoaspis sp. (now determined as belonging to the genus Neocypholaelaps), have been recorded (Veitch 1936, p. 93; Simmonds 1949, p. 42). Recently during routine quarantine examinations mites determined as Acarapis woodi (Rennie) were found externally on a worker honeybee in a queen bee consignment, from California, U.S.A. (Roff 1959). Following this, similar mites, stated to be Acarapis dorsalis or Acarapis woodi externus in the United States of America, have been located in various parts of North America. In Queensland, a quick survey has been made and Acarapis mites have been found on the thorax of worker honeybees from several Brisbane apiaries, and in several country areas extending from Warwick to Atherton. These widely spaced localities indicate that the mite must be of general distribution in the State.
اظهر المزيد [+] اقل [-]Yield and Mineral Composition of Eight Forage Species Grown at Four Levels of Soil Moisture النص الكامل
1960
Kilmer, Victor J. | Bennett, Orus L. | Stahly, Virginia F. | Timmons, Donald R.
SynopsisThe effect of soil moisture levels on the concentration of 12 elements was determined in fieldgrown Atlantic and African alfalfa; red, intermediate white, and Ladino clover; fescue, reed canarygrass, and orchardgrass. The phosphorus content in all forage species increased as soil moisture supply increased but other elements were not consistently affected.
اظهر المزيد [+] اقل [-]The analysis of tissue phospholipids: hydrolysis procedure and results with pig liver النص الكامل
1960
G. Hübscher | J.N. Hawthorne | P. Kemp
A procedure for the hydrolysis of phospholipids is described. The effect of alkali concentration, organic solvents, and length of hydrolysis have been studied. The initial reaction in the preferred solvent system appears to be a methanolysis. The phospholipids are converted quantitatively into water-soluble phosphates, which are separated and estimated by ion-exchange chromatography. In this way phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol may be determined in liver tissue.
اظهر المزيد [+] اقل [-]Determination of Reserve Sulfur and Soluble Sulfates in Soils النص الكامل
1960
Bardsley, C. E. | Lancaster, J. D.
Organic and reduced inorganic sulfur (reserve sulfur) are converted to sulfates by ignition of a soil-sodium bicarbonate mixture at 500° C. Converted and soluble sulfates (soil sulfur) are then extracted with a solution that is 2N to HAc and 0.1N to NaH₂PO₄·H₂O and determined turbidimetrically as BaSO₄ after acidifying a portion of the filtrate with 1:1 HCl. Acceptable recovery of sulfur has been obtained from elemental sulfur, plant material, methionine, cystine, and cysteine. Soluble sulfates are extracted from a separate sample with 0.5N NH₄OAc + 0.25N HAc. Activated charcoal is added to decolorize the extract. A portion of the filtrate is acidified with 1:1 HCl containing a “seed” solution of sulfate, and sulfur is determined turbidimetrically as BaSO₄. Reserve sulfur is the difference between soil sulfur and soluble sulfates. The multiple correlation of reserve and sulfate-sulfur with total nitrogen in soils was highly significant (R = 0.971). Reserve sulfur was highly correlated with yield of sulfur from three harvests of white clover grown in the greenhouse (R = 0.790). The relation of reserve sulfur and sulfates to the sulfur status of soils is discussed.
اظهر المزيد [+] اقل [-]The Physiological Nature of Gene-Controlled Growth Form in Trifolium Fragiferum L. I. Inheritance of Growth Form النص الكامل
1960
Bendixen, Leo E. | Stanford, E. H. | Peterson, M. L.
SynopsisErect versus stoloniferous growth form in Salina strawberry clover is determined by a single gene, with stoloniferous being dominant over erect. Somatic reversion to the stoloniferous form is common in erect plants. Apparent instability patterns among six erect parents and their progenies at the erect locus suggest genetic control of this instability.
اظهر المزيد [+] اقل [-]Sterility in Sudangrass: I. Barren- and Chimeral Partial-Sterility النص الكامل
1960
Townsend, C. E.
SynopsisA barren-sterile character, manifested by the absence of floral parts and sexual organs, was inherited as a monogenic recessive. A few seeds were observed on barren-sterile plants in one progeny. The chimeral partial-sterile character was believed to be controlled by recessive genes which were quite mutable. The mode of inheritance was not determined.
اظهر المزيد [+] اقل [-]Behavior of Sample Pleated Strips of Wool Fabric in an Extensometer النص الكامل
1960
Holdaway, H.W.
The simple theoretical model previously considered [1] was inadequate in some respects to provide a complete account of the observed elasto-mechanical behavior of a pleat when extended. Factors now included are the radius of curvature at the pleat and the variation in fabric stiffness as a function of tension. The use of additional parameters to take account of these effects permits a very good description of the ob served behavior. Values of "initial pleat angle" and "initial fabric stiffness" can be determined from experimental results of longitudinal extension and lateral deflection as a function of load.
اظهر المزيد [+] اقل [-]Der Einfluß von Gammastrahlen und Ultraschall auf Stärke النص الكامل
1960
Samec, M.
Changes are depicted that potato, wheat, and corn starch undergo under the influence of gamma rays and supersonic waves. The following characteristics were gauged: — viscosity, reducing power, PH value, iodine compound, molecular weight, ultrafiltrable portion, conduct on electrodialysis. The same characteristics were found in the fractions obtained by electrodialysis, and their phosphorus content determined. Both process make the extraction of suluble starches possible, the aqueous solution of which have good keeping qualities. The effect of gamma rays opens the possibility of using the waste energy arising in reactors.
اظهر المزيد [+] اقل [-]The Direct Nitration of Flax and Jute النص الكامل
1960
Lewin, Menachem | Epstein, Joseph A.
Three samples of flax and one sample of jute were nitrated with a mixture of HNO₃/H ₃PO₄/P₂O₅ for several lengths of time, ranging from to 72 hr. The crude nitrate, Fraction A, was extracted with acetone and the acetone extract precipitated with water, giving three fractions: A1, the acetone-soluble fraction precipitated by water, A2, the acetone-insoluble fraction, and A3, the acetone- and water-soluble fractions. The DP's of Fraction A1 were determined. The mode of variation of the amount of Fraction A2 with time of nitration suggests the existence of intercarhohycirate links in jute but not in flax.
اظهر المزيد [+] اقل [-]