An experimental study of the condensing characteristics of mercury vapor flowing in single tubes

Condensing characteristics of mercury vapor flowing in single tube

Optimum dry-cooling sub-systems for a solar air conditioner

Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost

Scaling analysis applied to the NORVEX code development and thermal energy flight experiment

A scaling analysis is used to study the dominant flow processes that occur in molten phase change material (PCM) under 1 g and microgravity conditions. Results of the scaling analysis are applied to the development of the NORVEX (NASA Oak Ridge Void Experiment) computer program and the preparation of the Thermal Energy Storage (TES) flight experiment. The NORVEX computer program which is being developed to predict melting and freezing with void formation in a 1 g or microgravity environment of the PCM is described. NORVEX predictions are compared with the scaling and similarity results. The approach to be used to validate NORVEX with TES flight data is also discussed. Similarity and scaling show that the inertial terms must be included as part of the momentum equation in either the 1 g or microgravity environment (a creeping flow assumption is invalid). A 10(exp -4) environment was found to be a suitable microgravity environment for the proposed PCM

Sestrins are evolutionarily conserved mediators of exercise benefits.

Exercise is among the most effective interventions for age-associated mobility decline and metabolic dysregulation. Although long-term endurance exercise promotes insulin sensitivity and expands respiratory capacity, genetic components and pathways mediating the metabolic benefits of exercise have remained elusive. Here, we show that Sestrins, a family of evolutionarily conserved exercise-inducible proteins, are critical mediators of exercise benefits. In both fly and mouse models, genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise and improving their endurance through training. Conversely, Sestrin upregulation mimics both molecular and physiological effects of exercise, suggesting that it could be a major effector of exercise metabolism. Among the various targets modulated by Sestrin in response to exercise, AKT and PGC1α are critical for the Sestrin effects in extending endurance. These results indicate that Sestrin is a key integrating factor that drives the benefits of chronic exercise to metabolism and physical endurance

Sestrins are evolutionarily conserved mediators of exercise benefits

Exercise is among the most effective interventions for age-associated mobility decline and metabolic dysregulation. Although long-term endurance exercise promotes insulin sensitivity and expands respiratory capacity, genetic components and pathways mediating the meta- bolic benefits of exercise have remained elusive. Here, we show that Sestrins, a family of evolutionarily conserved exercise-inducible proteins, are critical mediators of exercise ben- efits. In both fly and mouse models, genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise and improving their endurance through training. Conversely, Sestrin upregulation mimics both molecular and physiological effects of exercise, suggesting that it could be a major effector of exercise metabolism. Among the various targets modulated by Sestrin in response to exercise, AKT and PGC1α are critical for the Sestrin effects in extending endurance. These results indicate that Sestrin is a key integrating factor that drives the benefits of chronic exercise to metabolism and physical endurance

Genetic Heterogeneity in a Cyclical Forest Pest, the Southern Pine Beetle, Dendroctonus frontalis, is Differentiated Into East and West Groups in the Southeastern United States

The southern pine beetle, Dendroctonus frontalis Zimmerman (Coleoptera: Curculionidae) is an economically important pest species throughout the southeastern United States, Arizona, Mexico, and Central America. Previous research identified population structure among widely distant locations, yet failed to detect population structure among national forests in the state of Mississippi. This study uses microsatellite variation throughout the southeastern United States to compare the southern pine beetle's pattern of population structure to phylogeographic patterns in the region, and to provide information about dispersal. Bayesian clustering identified east and west genetic groups spanning multiple states. The east group had lower heterozygosity, possibly indicating greater habitat fragmentation or a more recent colonization. Significant genetic differentiation (θST = 0.01, p < 0.0001) followed an isolation-by-distance pattern (r = 0.39, p < 0.001) among samples, and a hierarchical AMOVA indicated slightly more differentiation occurred between multi-state groups. The observed population structure matches a previously identified phylogeographic pattern, division of groups along the Appalachian Mountain/Apalachicola River axis. Our results indicate that the species likely occurs as a large, stable metapopulation with considerable gene flow among subpopulations. Also, the relatively low magnitude of genetic differentiation among samples suggests that southern pine beetles may respond similarly to management across their range