A torsion test was developed for studying the structural failure of selected raw fruits and vegetables. Apple, melon and raw potato flesh were tested at a shear strain rate of approximately 0.26s‐1 in torsion and uniaxial compression. Low strain modulus values were determined in addition to shear stresses and normal strains at failure. Results corroborated the maximum normal strain failure criterion proposed by Segerlind and Dal Fabbro (1978) for apples and suggested its application to potatoes and melons if true strains are used rather than engineering strains. The maximum shear stress theory also seemed to be a possible failure criterion for potatoes. Results comparing compressible and incompressible materials suggest that bulk strain affects the shear stress at failure. The observed failure planes supported the quantitative results for stresses at failure. Scanning electron micrographs indicated that the cellular failure occurred in the cell wall, regardless of whether it was due to tension, Varying specimen lengths or diameters had negligible effects on the uniaxial compression modulus but did affect the shear stress at failure in a manner yet to be satisfactorily explained.

As our water reserves diminish, recycled water is increasingly being used for irrigation of turfgrasses. This study was conducted to determine the fate of nutrients contained in Type I recycled water used to irrigate turf and its effect on turf quality. Eighteen plots were randomly assigned to three replications of three irrigation treatments and two grasses. Irrigation treatments included Edwards Aquifer water applied at the evapotranspiration (ET) rate (EA), recycled water applied at the evapotranspiration rate (1XRW), and recycled water applied at 1.1 times the evapotranspiration rate to provide a leaching fraction (LFRW). Grasses included ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy) and ‘Jamur’ zoysiagrass (Zoysia japonica Steud.). Rain, runoff, leachate, and soil samples were collected and analyzed for total salts, Ca, Cu, Fe, Mg, Mn, N, K, Na, and Zn. The use of San Antonio Water System (SAWS) Type I recycled water had no adverse effect on turf quality but did result in a significant increase in soil electrical conductivity (EC) from 0.2518 dS m−1 in the EA treatment to 0.3132 and 0.3171 dS m−1 in the 1XRW and LFRW treatments, respectively. The Ca content increased from 134 108 and 135 467 mg L−1 in the EA and 1XRW treatments to 142 835 mg L−1 in the LFRW treatment. Na concentrations in the soil were not affected by the use of recycled water. The use of recycled water resulted in increased total salts (EC), Na and nitrate (NO3) concentrations in leachate passing below 76 cm. The EC increased from 0.425 dS m−1 for the EA treatment to 0.626 and 0.614 dS m−1 for the 1XRW and LFRW treatments, respectively. Na concentrations in leachate increased from 18.33 mg L−1 for the EA treatment to 49.10 and 52.91 mg L−1 for the 1XRW and LFRW treatments, respectively. Runoff water from treatments irrigated with recycled water exhibited a trend of increased EC, Ca, Mn, and Na.

Three fracture test methods: uniaxial compression, uniaxial tension and torsion were examined by interpreting results using theories upon which the methods were based. In each of these tests, the fracture of gels can occur as a result of shear, compression or tension. The fracture properties determined from uniaxial compression and tension were compared with torsion testing, a suitable reference technique. Shear stress and strain in uniaxial compression were comparable with shear stress and strain in torsion. However, the tensile stress in compression is not in agreement with that in torsion. Tensile stress or shear stress values in uniaxial tension were generally comparable with tensile or shear stress values in torsion, while the strain levels in uniaxial tension were typically much lower than those in uniaxial compression or torsion. This result could be related to the fracture strain being a function of elongation necessary to reduce the specimen cross section to an area producing the critical fracture stress. The comparison among different methods revealed shear stress and strain can be the fracture criteria for uniaxial compression, and tensile stress can be the fracture criterion for uniaxial tension, whereas

A device was developed for the nondestructive measure of body volume by air displacement. Two experiments were performed on Coturnix quail to determine the feasibility of using body density and volume of the live bird as criteria of selection for changing whole body lipid content. In Experiment 1,423 birds were used from three selected lines differing in adult weight. Three measurements of volume were taken on each bird. Repeatability of volume was consistently high for all line-sex subclasses, averaging .75. A phenotypic correlation of .55 was derived for body density and lipid content of the whole carcass. Estimates of heritabilities and genetic relationships for body density, volume and weight, and whole body lipid content were derived in Experiment 2 on 739 birds representing 50 sires and 125 dams of a randombred population. Heritability of volume averaged over full and half-sibs and over sexes was high (.66). The average genetic correlation for volume and lipid content was .44. Heritabilities of density averaged .38 and were highly genetically correlated (.69) with lipid content, which had an average heritability of .35. Body weight was very highly heritable in the population (.82) and correlated genetically with body lipid (.60).