Trade-offs among traits are important for maintaining biodiversity, but the role of natural selection in their construction is not often known. It is possible that trade-offs reflect fundamental constraints, negative correlational selection, or directional selection operating on costly, redundant traits. In a Sonoran Desert community of winter annual plants, we have identified a trade-off betwe...

In the present paper , dynamic characteristics of the pressure pulsation and heat exchange have been analyzed in cooler of reciprocating compressor. Through the analysis of energy balance for an heat exchange element , the differential equations are established for the heat exchange element. Effect of the pressure pulsation on heat exchange has been considered in the cooler of the compressor by...

Several optimal discharge pressure correlations for transcritical CO2 heat pump in literature have been discussed in this paper. Most of them are related to the ambient temperature, the evaporation temperature and the gas cooler outlet temperature. A revised optimal discharge pressure model as the function of ambient temperature and water outlet temperature is developed based on earlier experim...

The Texas Carbon Management Program is preparing a Front-End Engineering Design (FEED) of the PZASTM (Piperazine with Advanced StripperTM) for CO2 capture at natural gas combined cycle power plant in West Texas. This paper develops absorber design system and studies operational strategies response to ambient temperature swing. uses 2 trains, each train integrates absorption water-wash section o...

The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through trade-off analysis energy cost capital resulting from different temperature approaches cross-exchanger solvent-based CO2 capture process, was evaluated. aim to examine reduction emission potentials exchangers. Each specific type assumed for cross-exchanger, lean amine cooler cool d...

Trees are essential to urban habitats because they provide services that benefit the environment and improve human health. Unfortunately, urban trees often have more herbivorous insect pests than rural trees but the mechanisms and consequences of these infestations are not well documented. Here, we examine how temperature affects the abundance of a scale insect, Melanaspis tenebricosa (Comstock...

Traditional thermoelectric cooling relies on the Peltier effect which produces a temperature drop limited by the figure of merit, zT. This cooling limit is not required from classical thermodynamics but can be traced to problems of thermoelectric compatibility. Alternatively, if a thermoelectric cooler can be designed to achieve full thermoelectric compatibility, lower temperature can be achiev...

The gas-phase chemistry of water in protoplanetary disks is analyzed with a model based on X-ray heating and ionization of the disk atmosphere. Several uncertain processes appear to play critical roles in generating the column densities of warm water that are detected from disks at infrared wavelengths. The dominant factors are the reactions that form molecular hydrogen, including formation on ...

In this paper, a new R744 heat pump system is studied. The gas cooler, evaporator, indoor core, and cooler are all micro-channel exchangers. high pressure adopts combination of an accumulator internal exchanger (ACCU/IHX). addition, electronic reversible regulating valve added before the outdoor making able to be used as or evaporator. water-cooled condenser can improve performance in cooling h...

Internet routers conduct router-table lookup based on the destination IP address of the incoming packet to decide where to forward the packet. TCAM, which uses parallelism to achieve lookup in a single cycle, is a simple and efficient solution for router-table lookup. The major drawback of TCAM is its high power consumption. Trie based architecture proposed in. [1] can be used to reduce TCAM po...