SynopsisGene number affecting milling quality in a wheat cross (Norin 10 × Brevor-14) × Burt could not be determined using the partitioning method of genetic analysis. The components of variance were partitioned and a heritability of 35.50% was determined for this character. Estimates of expected genetic gain indicated good progress could be made in a recurrent selection program for milling quality as measured by the separation of bran and endosperm.

The moisture regain of viscose rayon in a saturated atmosphere has been estimated from measurements of the longitudinal swelling of the fiber at relative humidities ranging from dryness to saturation (water immersion). The density of viscose as a function of the regain has also been determined. From these data, the volume swelling and the swelling of the cross-sectional area of the fiber have been calculated. The latter values, at the saturation regain deduced from the axial swelling measurements, are in substantial agreement with values which other investigators have determined by quite different methods of measurement.

The vibroscope method of determining linear density of fibers is based on the prin ciple of the vibrating string, wherein the linear density is directly determined by tension and length of a fiber vibrating at resonance. In establishing a standard ASTM method for use of an instrument operating on this principle, the effect of three factors inherent in fibers had to be determined. These are (a) shape of fiber cross section. (b) area of cross section, and (c) Young's modulus. This paper is a report of the cooperative test program under ASTM auspices. Results indicated that equipment and procedure used without corrections for the effect of the various factors involved furnish reliable linear density measurements within about 5% of the denier value obtained.

The cation-exchange capacity of several soil minerals and fertilizer compounds has been determined. The exchange capacity of iron and aluminum phosphates was found to be approximately the same as or somewhat greater than that of Wyoming bentonite. Phosphate treatment of several horizons of 4 different soils was found to increase the cation-exchange capacity of these soils but not in proportion to the amount of phosphate fixed, except in the case of the 6 horizons of the Summit soil. Eight soil clay minerals or minerals closely related to soil clays were decomposed by grinding and the effect of phosphate treatment on their exchange capacity was determined. In most cases a major increase in cation-exchange capacity resulted from phosphate treatment, but in several cases a lesser numerical but significant decrease occurred. It is concluded that phosphate fertilization can noticeably effect an increase in the cation-exchange capacity of soils.

The availability of the phosphorus in two samples of an aluminium-iron rock phosphate has been determined in the rat. In evaluating these products live weight gains, the ash content of the femurs and total phosphorus retention have been used as criteria. The rock phosphate was found to be a poor source of phosphorus.

Plainfield sand was dry-sieved into the following five size fractions: 104 to 125, 125 to 149, 149 to 177, 177 to 210, and 210 to 250µ. The bulk densities of the sand fractions, when packed in a standard manner, averaged 1.65 ± 0.01 g. per cc. The particle densities of the fractions averaged 2.61 ± 0.01 g. per cc. The size distribution of each fraction was determined microscopically. The bulk density, particle density, and the reduced size-distribution curves indicated that the sand fractions could be considered similar media. Capillary conductivity as a function of the moisture tension was determined. When the reduced conductivity was plotted against the reduced tension, the data coalesced into one curve within the limits of experimental error. Moisture characteristic curves of the sand fractions also coalesced into one curve when the reduced tension was plotted against the volume moisture content. The results of this study seem to support the similar media concept.

Neste trabalho é apresentado, em detalhes, o projeto para à construção de uma barragem de terra, na qual foi empregada, com bons resultados, a impermeabilização do núcleo central por meio do hidróxido de sódio em solução a 3%. A impermeabilidade foi determinada durante a fase da construção, em amostras de solo de estrutura não deformada. Após a conclusão da reprêsa êsse efeito foi avaliado determinando-se a posição assumida pela linha de saturação, no interior do atêrro. Acham-se descritas, também, as técnicas usadas para a impermeabilização do núcleo e para a determinação da linha de saturação. | The purpose of this paper is to present a detailed project that may be helpful to others undertaking the building of an earth dam. Results obtained in an impermeable earth dam are presented; the impermeability was attained by sodium hydroxide treatment of its central core; the effect on the impermeability of the dam was determined from undisturbed samples collected during and after the construction period. The position reached by the saturation line in the external slope was determined in order to evaluate the effect of the treatment on the impermeability of the dam.

The suitability of lignin as a tracer substance, i.e. the apparent indigestibility of lignin, is dependent on the method used for the determination of lignin. Further, a method suitable for one food is not necessarily suitable for all kinds of food. By the method used in this investigation (method A) the mean digestibility of lignin from mature hay or from hay cured after blooming was found to be +1.8 ± 0.6 %. However, the mean digestibility of lignin from hay cut at an early stage of growth was +17.6 ± 1.0 %. When a pepsin pretreatment was included in the method (method B) the digestibility of crude lignin was found to be somewhat lower than the digestibility of lignin. The lignin determined by method A is more suitable for the lignin ratio technique (digestibility coefficient +1.8 ± 0.7. than the crude lignin determined by method B (digestibility coefficient +3.1 ± 0.9). The lignin preparations isolated from hay and from corresponding faeces have not a uniform composition. Appreciable differences appear in the methoxyl and in the nitrogen contents.

A method is described whereby soils may be calibrated with fiberglass soil moisture units at 15-atm. tension using the pressure membrane apparatus. Moisture units to be installed in the field were first calibrated in a shallow pan with a bulk soil sample taken from the site of the proposed field installation. Ten units were selected for further laboratory calibration and the remaining ones installed in the field. Soil samples were spooned into rubber rings, the moisture units imbedded in the soil, and the assemblies soaked overnight in distilled water. The soils and units were subjected to 15-atm. tension for 8 days, after which resistances were determined. Moisture content of the soils was determined in order to validate the run. This procedure was repeated with moisture units rearranged and placed in different soils. Statistical analysis indicate whether or not separate means are required for all soils. Field moisture curves indicate that under the conditions studied, resistance readings in the surface soil (2-inch depth) may rapidly pass through the wilting range (mean 15 atm., ± 1 standard deviation). Deeper installations in vegetated areas indicate leveling-off in the wilting range.

Sunflowers (Helianthus annuus, L.) were grown in 20 compacted soil separates, ranging in diameters from 4,760 to 2.31µ, which contained pores of diameters between 529 to 2.23µ. Two moisture levels, 20-cm. water tension and moisture content at “flex point,” were imposed on the 20 separates. Nutrient solution was applied to the separates. Noticeably different growth rates of sunflowers were measured at the two moisture levels. Maximum rate of stem elongation at 20-cm. water tension was nearly three-fold greater than was that at “flex point” moisture percentage. Maximum growth of sunflowers at 20-cm. water tension was obtained from separates between 52.3 and 210µ in diameter or pores with mean diameters of 17.7 to 43.5µ. Optimum growth of sunflowers at “flex point” moisture was on separates 13.1 to 9.25µ in diameter whose pores were about 4µ in diameter. Aeration appeared to limit the rate of stem elongation when air occupied less than 4% of the pore space. Maximum growth rate of sunflowers at both moisture levels apparently was determined by the influence of pore size upon aeration and area of root-solution contact. The greater the area of root-solution contact, as determined by pore size and moisture tension, the more favorable was the growth of roots and shoots, provided aeration was not limiting.