Heat Pump-Based Novel Energy System for High-Power LED Lamp Cooling and Waste Heat Recovery

Unlike incandescent light bulb, which radiates heat into the surroundings by infrared rays, light emitting diode (LED) traps heat inside the lamp. This fact increases the difficulty of cooling LED lamps, while it facilitates the recovery of the generated heat. We propose a novel energy system that merges high-power LED lamp cooling with the heat pump use; the heat pump can cool the LED lamp and at the same time recover the waste heat. In this way, a high percentage of the energy consumed by the LED lamp can be utilized. In this work, we developed a prototype of this energy system and conducted a series of experimental studies to determine the effect of several parameters, such as cooling water flow rate and LED power, on the LED leadframe temperature, compressor power consumption, and system performance. The experimental results clearly indicate that the energy system can lead to substantial energy savings

Complex population genetic and demographic history of the Salangid, Neosalanx taihuensis, based on cytochrome b sequences

<p>Abstract</p> <p>Background</p> <p>The Salangid icefish <it>Neosalanx taihuensis </it>(Salangidae) is an economically important fish, which is endemic to China, restricted to large freshwater systems (e.g. lakes, large rivers and estuaries) and typically exhibit low vagility. The continuous distribution ranges from the temperate region of the Huai and Yellow River basins to the subtropical region of the Pearl River basin. This wide ranging distribution makes the species an ideal model for the study of palaeoclimatic effects on population genetic structure and phylogeography. Here, we aim to analyze population genetic differentiation within and between river basins and demographic history in order to understand how this species responded to severe climatic oscillations, decline of the sea levels during the Pleistocene ice ages and tectonic activity.</p> <p>Results</p> <p>We obtained the complete mtDNA cytochrome <it>b </it>sequences (1141 bp) of 354 individuals from 13 populations in the Pearl River, the Yangze River and the Huai River basin. Thirty-six haplotypes were detected. Haplotype frequency distributions were strongly skewed, with most haplotypes (n = 24) represented only in single samples each and thus restricted to a single population. The most common haplotype (H36) was found in 49.15% of all individuals. Analysis of molecular variance (AMOVA) revealed a random pattern in the distribution of genetic diversity, which is inconsistent with contemporary hydrological structure. Significant levels of genetic subdivision were detected among populations within basins rather than between the three basins. Demographic analysis revealed that the population size in the Pearl River basin has remained relatively constant whereas the populations in the Yangze River and the Huai River basins expanded about 221 and 190 kyr ago, respectively, with the majority of mutations occurring after the last glacial maximum (LGM).</p> <p>Conclusion</p> <p>The observed complex genetic pattern of <it>N. taihuensis </it>is coherent with a scenario of multiple unrelated founding events by long-distance colonization and dispersal combined with contiguous population expansion and locally restricted gene flow. We also found that this species was likely severely impacted by past glaciations. More favourable climate and the formation of large suitable habitations together facilitated population expansion after the late Quaternary (especially the LGM). We proposed that all populations should be managed and conserved separately, especially for habitat protection.</p

Baiji genomes reveal low genetic variability and new insights into secondary aquatic adaptations

The baiji, or Yangtze River dolphin (Lipotes vexillifer), is a flagship species for the conservation of aquatic animals and ecosystems in the Yangtze River of China; however, this species has now been recognized as functionally extinct. Here we report a high-quality draft genome and three re-sequenced genomes of L. vexillifer using Illumina short-read sequencing technology. Comparative genomic analyses reveal that cetaceans have a slow molecular clock and molecular adaptations to their aquatic lifestyle. We also find a significantly lower number of heterozygous single nucleotide polymorphisms in the baiji compared to all other mammalian genomes reported thus far. A reconstruction of the demographic history of the baiji indicates that a bottleneck occurred near the end of the last deglaciation, a time coinciding with a rapid decrease in temperature and the rise of eustatic sea level

Power Generation on a Bare Electrodynamic Tether during Debris Mitigation in Space

Power generation can be realized in space when current is induced on a bare electrodynamic tether system. The performance of power generation is discussed based on a debris mitigation mission by numerical simulation in the paper. A Li-ion battery subsystem is used to complete the energy conversion—harvest and supply the energy. The battery can provide 10–300 W average electric power continuously during several hundred hour mission time. The energy conversion efficiency ranges from 1% to a maximum value 30%. With constant power consumption on board, the battery operation generally experiences a discharging phase, a charging phase, and a stable phase. The first two phases determine the mission risk coefficient. The heating problem in the stable phase cannot be ignored. The optimization of battery design and tether design should be considered for each debris mitigation mission. An extra control circuit or small battery voltage with large capacity for battery design is suggested to eliminate the stable phase. Wide or long tether designs are more appropriate for mission with high or low power demands on board, respectively. The power generation is affected by the system mass and the mission orbit parameters

Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences-4

TMRCA (kyr) in generations using a mutation rate of 1% × 10per year. The tree shows the ancestral distribution of mutations and events (TMRCA, recent rapid expansion) in the population history.<p><b>Copyright information:</b></p><p>Taken from "Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences"</p><p>http://www.biomedcentral.com/1471-2148/8/201</p><p>BMC Evolutionary Biology 2008;8():201-201.</p><p>Published online 14 Jul 2008</p><p>PMCID:PMC2483725.</p><p></p

Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences-0

Ch node based on maximum likelihood inference.<p><b>Copyright information:</b></p><p>Taken from "Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences"</p><p>http://www.biomedcentral.com/1471-2148/8/201</p><p>BMC Evolutionary Biology 2008;8():201-201.</p><p>Published online 14 Jul 2008</p><p>PMCID:PMC2483725.</p><p></p

Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences-2

to . Classic skyline was shown as thin line, generalized skyline as thick line, and dot line as the expected demographic history.<p><b>Copyright information:</b></p><p>Taken from "Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences"</p><p>http://www.biomedcentral.com/1471-2148/8/201</p><p>BMC Evolutionary Biology 2008;8():201-201.</p><p>Published online 14 Jul 2008</p><p>PMCID:PMC2483725.</p><p></p

Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences-1

Te undetected intermediate haplotype states separated by one mutational step. Boxes indicate one-step to two-step nesting levels for the nested clade analysis in NCA.<p><b>Copyright information:</b></p><p>Taken from "Complex population genetic and demographic history of the Salangid, , based on cytochrome b sequences"</p><p>http://www.biomedcentral.com/1471-2148/8/201</p><p>BMC Evolutionary Biology 2008;8():201-201.</p><p>Published online 14 Jul 2008</p><p>PMCID:PMC2483725.</p><p></p