Genetic control of differential baseline breathing pattern

The purpose of the present study was to determine the genetic control of baseline breathing pattern by examining the mode of inheritance between two inbred murine strains with differential breathing characteristics. Specifically, the rapid, shallow phenotype of the C57BL/6J (B6) strain is consistently distinct from the slow, deep phenotype of the C3H/HeJ (C3) strain. The response distributions of segregant and nonsegregant progeny were compared with the two progenitor strains to determine the mode of inheritance for each ventilatory characteristic. The BXH recombinant inbred (RI) strains derived from the B6 and C3 progenitors were examined to establish strain distribution patterns for each ventilatory trait. To establish the mode of inheritance, baseline breathing frequency (f), tidal volume, and inspiratory time (TI) were measured five times in each of 178 mature male animals from the two progenitor strains and their progeny by using whole body plethysmography. With respect to f and TI, the two progenitor strains were consistently distinct, and segregation analyses of the inheritance pattern suggest that the most parsimonious genetic model for response distributions of f and TI is a two-loci model. In similar experiments conducted on 82 mature male animals from 12 BXH RI strains, each parental phenotype was represented by one or more of the RI strains. Intermediate phenotypes emerged to confirm the likelihood that parental strain differences in f and TI were determined by more than one locus. Taken together, these studies suggest that the phenotypic difference in baseline respiratory timing between male B6 and C3 mice is best explained by a genetic model that considers at least two loci as major determinants.     

Heat exchange between strands and guide rollers in the secondary cooling zone of a slab continuous casting machine

Measuring of temperatures at different distances from the surface of the guide rollers without inside cooling in the secondary cooling zone of slab caster. Computation of the temperature field of the rollers and the flows of heat into and out of the rollers by using mathematical models. Discussion about the influence of the length of the strand and the cooling conditions. Comparison with the heat transfer by spray cooling.     

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Resource pool management: Reactive versus proactive or let’s be friends

The consolidation of multiple workloads and servers enables the efficient use of server and power resources in shared resource pools. We employ a trace-based workload placement controller that uses historical information to periodically and proactively reassign workloads to servers subject to their quality of service objectives. A reactive migration controller is introduced that detects server overload and underload conditions. It initiates the migration of workloads when the demand for resources exceeds supply. Furthermore, it dynamically adds and removes servers to maintain a balance of supply and demand for capacity while minimizing power usage. A host load simulation environment is used to evaluate several different management policies for the controllers in a time effective manner. A case study involving three months of data for 138 SAP applications compares three integrated controller approaches with the use of each controller separately. The study considers trade-offs between: (i) required capacity and power usage, (ii) resource access quality of service for CPU and memory resources, and (iii) the number of migrations. Our study sheds light on the question of whether a reactive controller or proactive workload placement controller alone is adequate for resource pool management. The results show that the most tightly integrated controller approach offers the best results in terms of capacity and quality but requires more migrations per hour than the other strategies.     

Calculation of the temperature distribution in dieless drawing

Dieless drawing is an example of flexible metal forming processes. The investigation of the main process parameters and their interdependence is the prerequisite for the deliberate choice of input parameters to get the desired quality of the workpiece. Drawing force, drawing velocity, and temperature are the main control parameters. But only the temperature can be influenced locally whereas the force and the velocity can be adjusted only globally. Because of this special importance of the temperature analytical and numerical models for the temperature distribution along the deformation zone have been developed.     

Fluiddynamische Untersuchung eines konischen Turbinenrührers

Zusammenfassung In der vorliegenden Arbeit werden die Ergebnisse einer experimentellen Untersuchung mit Laser-Doppler-Anemometrie an einem konischen Dispergierrührer mitgeteilt. Ziel der Untersuchung war es, den konischen Rührer, der zum Dispergieren eingesetzt werden soll, hinsichtlich seiner fluiddynamischen Eigenschaften zu charakterisieren und mit dem 6-Blatt-Schreibenrührer zu vergleichen. Es hat sich gezeigt, da? der untersuchte Rührer neben einer recht guten Umw?lzleistung, die durch den Pumpbeiwert ausgedrückt wird, auch noch über Vorraussetzungen verfügt, die gute Dispergierf?higkeiten erwarten lassen. Dies wird durch Vergleich mit bekannten Ergebnissen für den 6-Blatt-Scheibenrührer belegt. Das Feld der lokalen spezifischen Energiedissipationsraten wurde aus den gemessenen lokalen Schwankungsgeschwindigkeiten u′ (RMS-Wert) berechnet. Die maximalen Energiedissipationsraten sind etwa 12 mal so gro? wie der mittlere Leistungseintrag.     

Attrition and secondary nucleation in crystallizers

The mean crystal size of coarse crystalline products is determined by secondary nucleation and crystal growth. Secondary unclei are mainly produced by contacts of crystals with parts of the crystallizer or with other crystals. As a consequence, attrition effects are very important. In this paper, a model is proposed in order to calculate the attrition rate of crystals, depending on the physical properties of the crystalline product, the geometry of the crystallizer and on the operating conditions such as the stirrer speed or the suspension density. The effective rate of secondary nucleation can be expressed in terms of the attrition rate by introducing effective values for number and size of attrition particles. Finally, a scale-up criterion based on this model is derived. This criterion allows to predict effective rates of secondary nucleation and mean crystal sizes if data obtained in a laboratory crystallizer are available.