2,830 research outputs found

    Josh's Battery - a more even relationship with the grid

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    Josh's House is a “living laboratory” research and demonstration project in the Perth suburb of Hilton, Western Australia. The scope of Josh's House included the design and construction of two energy efficient family homes that achieved the highest level, 10-stars (estimated thermal load: 4 MJ/m2/year) [Australian Government Department of Environment, Star rating scale overview, 2015 (Online), http://www.nathers.gov.au/owners-and-builders/star-rating-scale-overview, accessed on: 2017/17/07], under the Nationwide House Energy Rating Scheme. The project partners include the Co-operative Research Centre for Low Carbon Living and Curtin University. In mid-2015, a further research component was added to Josh's House involving the installation and ongoing monitoring of a battery storage system. This system is a domestic example of a distributed energy storage system (DESS) and is here referred to “Josh's Battery” or “the DESS”. The aim of the project is, in the first instance, to make domestic DESS data publicly available. Broader project objectives are to trial the technology, test assumptions on performance, document and communicate lessons and outcomes, and to inform further research and development. This paper provides an analysis of the monitoring data produced during the energy storage system's first year of operation. Particular areas of interest include: interaction with the electricity grid before and after installation of the storage system; correlation of system performance to specifications and modelled predictions; anomalies and unexpected results; and lessons learned from the installation and operation of the system. Implications and influences. The significance of this research is that it is built around the first monitored, grid connected domestic energy storage system in the Perth metropolitan area. It provides unprecedented data on how these systems can be expected to operate when embedded into a large-scale electricity network. The project also gives the opportunity to test some fundamental assumptions about these systems and feed into policy and business case development for the distributed energy storage sector, more broadly

    Discovery of a Galaxy Cluster in the Foreground of the Wide-Separation Quasar Pair UM425

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    We report the discovery of a cluster of galaxies in the field of UM425, a pair of quasars separated by 6.5arcsec. Based on this finding, we revisit the long-standing question of whether this quasar pair is a binary quasar or a wide-separation lens. Previous work has shown that both quasars are at z=1.465 and show broad absorption lines. No evidence for a lensing galaxy has been found between the quasars, but there were two hints of a foreground cluster: diffuse X-ray emission observed with Chandra, and an excess of faint galaxies observed with the Hubble Space Telescope. Here we show, via VLT spectroscopy, that there is a spike in the redshift histogram of galaxies at z=0.77. We estimate the chance of finding a random velocity structure of such significance to be about 5%, and thereby interpret the diffuse X-ray emission as originating from z=0.77, rather than the quasar redshift. The mass of the cluster, as estimated from either the velocity dispersion of the z=0.77 galaxies or the X-ray luminosity of the diffuse emission, would be consistent with the theoretical mass required for gravitational lensing. The positional offset between the X-ray centroid and the expected location of the mass centroid is about 40kpc, which is not too different from offsets observed in lower redshift clusters. However, UM425 would be an unusual gravitational lens, by virtue of the absence of a bright primary lensing galaxy. Unless the mass-to-light ratio of the galaxy is at least 80 times larger than usual, the lensing hypothesis requires that the galaxy group or cluster plays a uniquely important role in producing the observed deflections. Based on observations performed with the Very Large Telescope at the European Southern Observatory, Paranal, Chile.Comment: 12 pages, accepted by ApJ 2005, May 1

    Epidural Analgesia Decreases Narcotic Requirements in Low Level Spina Bifida Patients Undergoing Urologic Laparotomy for Neurogenic Bladder and Bowel

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    Purpose Concern of anatomical anomalies and worsening neurologic symptoms has prevented widespread use of epidural catheters in patients with low level spina bifida (LLSB). We hypothesize that thoracic epidural placement in the T9-T10 interspace is safe and decreases narcotic requirements in LLSB patients following major open lower urinary tract reconstruction (LUTR). Materials and Methods We reviewed consecutive LLSB patients who had LUTR and epidurals for post-operative pain control. Controls were LLSB patients who received single shot transversus abdominis plane (TAP) blocks with similar procedures. Complications from epidural placement, including changes in motor and sensory status were recorded. Opioid consumption was calculated utilizing equivalent IV morphine doses. Mean and maximum pain scores on post-operative day (POD) 0-3 were calculated. Results 10 LLSB patients who had lower urinary tract reconstruction and epidurals were matched to 10 LLSB patients who had lower urinary tract reconstruction and transverse abdominis plane blocks. Groups were demographically similar. All had full abdominal sensation and functional levels at or below L3. No epidural complications or changes in neurological status were noted. The epidural group had decreased opioid consumption on POD 0-3 (0.75 mg/kg vs. 1.29 mg/kg, p=0.04). Pain scores were similar or improved in the epidural group. Conclusions Thoracic epidural analgesia appears to be a safe and effective opioid sparing option to assist with post-operative pain management following lower urinary tract reconstruction in LLSB patients

    Global marine bacterial diversity peaks at high latitudes in winter.

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    Genomic approaches to characterizing bacterial communities are revealing significant differences in diversity and composition between environments. But bacterial distributions have not been mapped at a global scale. Although current community surveys are way too sparse to map global diversity patterns directly, there is now sufficient data to fit accurate models of how bacterial distributions vary across different environments and to make global scale maps from these models. We apply this approach to map the global distributions of bacteria in marine surface waters. Our spatially and temporally explicit predictions suggest that bacterial diversity peaks in temperate latitudes across the world's oceans. These global peaks are seasonal, occurring 6 months apart in the two hemispheres, in the boreal and austral winters. This pattern is quite different from the tropical, seasonally consistent diversity patterns observed for most macroorganisms. However, like other marine organisms, surface water bacteria are particularly diverse in regions of high human environmental impacts on the oceans. Our maps provide the first picture of bacterial distributions at a global scale and suggest important differences between the diversity patterns of bacteria compared with other organisms
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