The 1993 Shuttle Small Payloads Symposium

The 1993 Shuttle Small Payloads Symposium is a combined symposia of the Get Away Special (GAS), Hitchhiker, and Complex Autonomous Payloads (CAP) programs, and is proposed to continue as an annual conference. The focus of this conference is to educate potential Space Shuttle Payload Bay users as to the types of carrier systems provided and for current users to share experiment concepts

The 1992 Shuttle Small Payloads Symposium

The 1992 Shuttle Small Payloads Symposium is a continuation of the Get Away Special Symposium convened from 1984 through 1988, and is proposed to continue as an annual conference. The focus of this conference is to educate potential Space Shuttle Payload Bay users as to the types of carrier systems provided and for current users to share experiment concepts

The 1986 Get Away Special Experimenter's Symposium

The 1986 Get Away Special (GAS) Experimenter's Symposium will provide a formal opportunity for GAS Experimenter's to share the results of their projects. The focus of this symposium is on payloads that will be flown in the future

Impact of Hybrid Energy Storage System Topology on Performance: Exploration for Hydropower Hybrids

We investigate the technical performance of six HESS topologies integrated with run-of-river (ROR) hydropower to provide frequency support. We choose ROR hydropower because there are 23 GW of installed ROR hydropower in the U.S. and integrating these plants with energy storage could boost their contribution to grid services. We focus on HESSs composed of batteries and ultra-capacitors because batteries are cost effective for storing energy but degrade more quickly as a function of cycling. In contrast, ultra-capacitors can be cycled millions of times and are cost effective for quick injections of power. We find that active HESS topologies demonstrate the best overall improvement to grid frequency during a contingency while adhering to the power ramping limits of the HESS devices. Future work will investigate other services to identify if one HESS topology performs best for all services of interest or, more likely, different HESS topologies are best suited for specific services

A Study of the Impact of Reduced Inertia in Power Systems

Inertia in power systems plays an important role in maintaining the stability and reliability of the system by counteracting changes in frequency. However, the traditional sources of synchronous generation are being displaced by renewable resources, which often have no inherent inertia. This paper investigates the impact of reduced system inertia on several aspects of the dynamic stability of power systems, such as angular stability, primary frequency response, and oscillatory modes. This study is performed on a large-scale 2000 bus synthetic Texas model by selectively replacing synchronous generators with inverter-based generation resources. This paper also compares the analysis results obtained by the above-mentioned inertia-reduction approach of renewable integration with another approach in which the inertia constant of all synchronous generators is decreased. This paper demonstrates that only reducing the inertia of all synchronous generators in a system does not provide an accurate analysis of the challenges associated with the reduced system inertia caused by renewable integration

30-Arcsecond monthly climate surfaces with global land coverage

Monthly total precipitation and mean temperature climate surfaces, gridded to 30-arcseconds (≈1 km at the equator) and available for all global land areas, are presented. These datasets are generated with a Delta downscaling method, using the 30-arcsecond WorldClim climatologies to scale monthly anomaly grids. For monthly mean temperature, the anomalies are constructed from both the Climate Research Unit (CRU) and Willmott & Matsuura (W&M) 0.5 degree time-series datasets, whereas for monthly precipitation Global Precipitation Climatology Centre (GPCC) data are also used. The 0.5 degree anomalies are then interpolated to the 30-arcsecond resolution. Use of piecewise cubic Hermite interpolating polynomials (PCHIP) to interpolate the anomaly grids results in more physically representative Delta downscaled surfaces, compared to bilinear and cubic spline interpolation. The Delta downscaled products are compared to Global Historical Climatology Network (GHCN) station records for six test regions distributed globally. In this analysis, the Delta grids produced using the W&M time-series dataset perform better than grids produced using GPCC or CRU. Using Oregon, USA as a test region, the Delta downscaled datasets are compared to the Parameter-elevation Regressions on Independent Slopes Model (PRISM) datasets. For monthly precipitation, PRISM performs better than each of the three Delta downscaled datasets, but for mean temperature both Delta downscaled datasets outperform PRISM. Through computing the Pearson product–moment correlation coefficient between GHCN station delineated errors in the WorldClim climatologies and the Delta downscaled W&M data, it is shown that performance of the Delta grids corresponds strongly to performance of the reference climatologies. Therefore, future improvement of the 30-arcsecond Delta grids described in this article is strongly tied to advances in the high-resolution climatological data for all global land surfaces. The Delta downscaled datasets discussed herein are open-source and freely distributed at http://www.globalclimatedata.org.This is the publisher’s final pdf. The article is copyrighted by the Royal Meteorological Society and published by John Wiley & Sons Ltd. It can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291097-0088.Keywords: high resolution, precipitation, monthly time-series, mean temperature, downscaling, global climate dat

Contribution of nitrification and denitrification to N2O emissions from urine patches

Urine deposition by grazing livestock causes an immediate increase in nitrous oxide (N2O) emissions, but the responsible mechanisms are not well understood. A nitrogen-15 (15N) labelling study was conducted in an organic grass-clover sward to examine the initial effect of urine on the rates and N2O loss ratio of nitrification (i.e. moles of N2O-N produced per moles of nitrate produced) and denitrification (i.e. moles of N2O produced per moles of N2O + N2 produced). The effect of artificial urine (52.9 g N m-2) and ammonium solution (52.9 g N m-2) was examined in separate experiments at 45 and 35% water-filled pore space (WFPS), respectively, and in each experiment a water control was included. The N2O loss derived from nitrification or denitrification was determined in the field immediately after application of 15N-labelled solutions. During the next 24 h, gross nitrification rates were measured in the field, whereas the denitrification rates were measured in soil cores in the laboratory. Compared with the water control, urine application increased the N2O emission from 3.9 to 42.3 μg N2O-N m-2 h-1, whereas application of ammonium increased the emission from 0.9 to 6.1 μg N2O-N m-2 h-1. In the urine-affected soil, nitrification and denitrification contributed equally to the N2O emission, and the increased N2O loss resulted from a combination of higher rates and higher N2O loss ratios of the processes. In the present study, an enhanced nitrification rate seemed to be the most important factor explaining the high initial N2O emission from urine patches deposited on well-aerated soils

Transcend: A Thin-Shell Japanese Onsen Experience

This project is an interdisciplinary architectural design of a funicular Japanese onsen utilizing the compressive strength of thin-shell concrete. A section of this project was also built to scale on the Cal Poly campus in the Architectural Engineering department\u27s High Bay facility. This project was designed utilizing Rhinoceros and analyzed using SAP 2000 19

Tacrolimus pretreatment attenuates preexisting xenospecific immunity and abrogates hyperacute rejection in a presensitized hamster to rat liver transplant model

In the hamster to rat liver transplant model, we determined the efficacy of tacrolimus in attenuating natural xenospecific humoral immunity and in abrogating the hyperacute liver rejection that is produced by presensitizing the Lewis rat recipient. Hamster livers, transplanted orthotopically into naive rats (controls), were rejected with animal death after 6.4±0.5 (SD) days. The infusion on (day -6) of 1.5 x 107 hamster hepatocytes, or of 1.5 x 108 nonparenchymal cells (NPC), resulted in hyperacute rejection and death in ≤1.9 days. However, when the rats were pretreated with 1 mg/kg/day tacrolimus from days -6 to -1, survival of non-presensitized animals was prolonged to 25±20 days and that of recipients presensitized with hamster hepatocytes to 36±16 days or with NPC to 32±1.7 days. The tacrolimus pretreatment significantly reduced the hamster-specific complement-dependent cytotoxic antibodies response directed to liver NPC but not to lymph node cell targets. These observations suggest that the prolongation of survival by appropriately timed treatment with this T cell directed drug model is caused by the inhibition of humoral as well as cellular xenograft rejection

Effects of Surgical Correction for the Treatment of Adult Acquired Flatfoot Deformity: A Computational Investigation

Computational models of the foot/ankle complex were developed to predict the biomechanical consequences of surgical procedures that correct for Stage II adult acquired flatfoot deformity. Cadaveric leg and foot bony anatomy was captured by CT imaging in neutral flexion and imported to the modeling software. Ligaments were approximated as tension only springs attached at insertion sites. Muscle contraction of the gastrocnemius/soleus complex was simulated through force vectors and desired external loads applied to the model. Ligament stiffnesses were modified to reflect Stage II flatfoot damage, followed by integration of corrective osteotomies—medializing calcaneal osteotomy (MCO) and Evans and calcaneocuboid distraction arthrodesis (CCDA)—to treat flatfoot. Joint angles, tissue strains, calcaneocuboid contact force, and plantar loads were analyzed. The flatfoot simulation demonstrated clinical signs of disease evidenced by degradation of joint alignment. Repair states corrected these joint misalignments with MCO having greatest impact in the hindfoot, and Evans/CCDA having greatest effect in the mid- and forefoot. The lateral procedures unevenly strained plantar structures, while offloading the medial forefoot, and increased loading on the lateral forefoot, which was amplified by combining with MCO. The Evans procedure raised calcaneocuboid joint contact force to twice intact levels. Computational results are in agreement with clinical and experimental findings. The model demonstrated potential precursors to such complications as lateral tightness and arthritic development and may thus be useful as a predictor of surgical outcomes. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1047–1054, 201