Prompt fission-neutron spectra in the reactions of 1.5-MeV neutrons with235U

Translated from Atomnaya énergiya, Vol. 69, No. 1, pp. 28–31, July, 1990.     

Modified Atmosphere-packed Marinated Chicken Breast and Rainbow Trout Quality as Affected by Package Leakage

Marinated chicken breast pieces and sliced rainbow trout were packed in modified atmosphere and stored to measure effects of package leakage. The sensory shelf life of products decreased slowly but linearly as leakage rate increased, with exception of the appearance of sliced rainbow trout, which was not affected by leakage rate. The concentration of ethanol in head space was a potential indicator of spoilage and package leakage for both products. The presence of dimethylsulfide indicated spoilage of chicken fillet and acetone indicated leakage in sliced trout packages. A redox leakage color-indicator functioned properly in package lids.     

Colloidal particle aggregation in three dimensions

Colloidal systems are of importance not only for everyday products, but also for the development of new advanced materials. In many applications, it is crucial to understand and control colloidal interaction. In this paper, we study colloidal particle aggregation of silica nanoparticles, where the data are given in a three-dimensional micrograph obtained by high-angle annular dark field scanning transmission electron microscopy tomography. We investigate whether dynamic models for particle aggregation, namely the diffusion limited cluster aggregation and the reaction limited cluster aggregation models, can be used to construct structures present in the scanning transmission electron microscopy data. We compare the experimentally obtained silica aggregate to the simulated postaggregated structures obtained by the dynamic models. In addition, we fit static Gibbs point process models, which are commonly used models for point patterns with interactions, to the silica data. We were able to simulate structures similar to the silica structures by using Gibbs point process models. By fitting Gibbs models to the simulated cluster aggregation patterns, we saw that a smaller probability of aggregation would be needed to construct structures similar to the observed silica particle structure.     

Hot and cold rolling of high nitrogen Cr-Ni and Cr-Mn austenitic stainless steels

Behavior of austenitic Cr-Ni-(0.14-0.50)N and Cr-Mn-(0.78-1.00)N steels in hot and cold rolling was investigated by rolling experiments and mechanical testing. Structure of the steels in the as-cast condition and fracture surfaces after the rolling experiments were investigated using optical and scanning electron microscopy (SEM). Resistance to deformation was calculated using rolling forces in hot rolling. Increase in strength in the rolling experiments was related to the nitrogen content of the steels. Resistance to deformation during hot rolling increased with decreasing rolling temperature and with increasing nitrogen content. In some steels, hot rolling led to edge cracking, which was more a function of impurity than nitrogen content. Microscopy revealed that the edge cracking occurred along grain boundaries and second phase particles. For the cold-rolled steels, the highest achievable reductions were limited due to a “crocodiling” phenomenon, that is, opening of the strip end. Fracture type at the opened strip end was a brittle-like fracture.     

Fracture toughness and growth of short and long fatigue cracks in ductile cast iron EN‐GJS‐400‐18‐LT

Heavy components of ductile cast iron frequently exhibit metallurgical defects that behave like cracks under cyclic loading. Thus, in order to decide whether a given defect is permissible, it is important to establish the fatigue crack growth properties of the material. In this paper, results from a comprehensive study of ductile cast iron EN‐GJS‐400‐18‐LT have been reported. Growth rates of fatigue cracks ranging from a few tenths of a millimetre (‘short’ cracks) to several millimetres (‘long’ cracks) have been measured for load ratios R=?1, R= 0 and R= 0.5 using a highly sensitive potential‐drop technique. Short cracks were observed to grow faster than long cracks. The threshold stress intensity range, ΔK_th, as a function of the load ratio was fitted to a simple crack closure model. Fatigue crack growth data were compared with data from other laboratories. Single plain fatigue tests at R=?1 and R= 0 were also carried out. Fracture toughness was measured at temperatures ranging from ?40 °C to room temperature.     

Short communication: Teat-end shape and udder-level milking characteristics and their associations with machine milking-induced changes in teat tissue condition

Machine milking-induced changes in teat tissue condition, such as congestion and edema, have been associated with teat canal openness, penetrability, and thus susceptibility to new intramammary infections and diminished animal well-being. The primary objective of this study was to investigate the association of teat-end shape and machine milking-induced short-term changes in teat tissue condition. Our secondary objective was to study the association of udder-level milking characteristics and short-term changes. Data from 125 Holstein cows were analyzed in a longitudinal prospective cohort study. Cows were housed in freestall pens with sand bedding, fed a total mixed ration, and milked 3 times per day. Teat-end shape was classified into 3 categories: pointed, flat, and round. Udder-level milking characteristics were obtained from electronic on-farm milk meters. Short-term changes in teat tissue condition after machine milking were assessed visually. Multivariable generalized mixed model analysis showed an association between teat-end shape and short-term changes. Compared with teats with round teat-end shape, the odds ratio (95% confidence interval) for short-term changes was 1.68 (0.53–5.31) and 0.03 (0.004–0.19) in teats with pointed and flat teat-end shape, respectively. There was an association between milking characteristics and short-term changes such that higher milk flow rate during the first 15 s of milking decreased the likelihood of short-term changes. The adjusted probability of short-term changes for a milking observation of a mid-lactation cow and an average first 15-s milk flow rate of 0.5 and 1.5 kg/min was 53.0% (42.8–63.8) and 32.9% (15.2–57.3), respectively. Our results suggest that teat-end shape may be one of the risk factors that contribute to machine milking-induced short-term changes. Milking characteristics (e.g., first 15-s milk flow rate) may have the potential as a measure to indirectly monitor teat tissue changes associated with machine milking on a daily basis, though further research is needed to validate this hypothesis and to establish thresholds that could serve as on-farm guidelines.     

Die elektrische Festigkeit verdichteter Gase

Zusammenfassung Eine Anordnung für Durchschlagsversuche in verdichteter Luft und Stickstoff bis zu 40 atü wird beschrieben. Die Messungen im ebenen Feld ergänzen frühere Untersuchungen anderer Verfasser. Die Messungen im ungleichförmigen Feld mit Kugeln verschiedenen Durchmessers gegen Platte, mit Spitze gegen Platte sowie Spitze gegen Spitze dienen der systematischen Durchforschung dieses bis jetzt kaum beachteten Gebietes und erbringen interessante Züge über die Druckabhängigkeit der Durchschlagspannung für beide Polaritäten. Für den Fall Spitze gegen Platte werden die Untersuchungen auch auf Kohlensäure ausgedehnt.Von der T. H. Karlsruhe genehmigte Dissertation.