2,697 research outputs found

    RISK ANALYSIS OF ADOPTING ZERO RUNOFF SUBIRRIGATION SYSTEMS IN GREENHOUSE OPERATIONS: A MONTE CARLO SIMULATION APPROACH

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    Zero runoff subirrigation (ZRS) technology can effectively manage fertilizer input while improving greenhouse production efficiency. However, high capital investment costs and inadequate technical information to growers are impediments for adoption. A Monte Carlo simulation was used to compare the profitability and risks of alternative ZRS system investments for greenhouse operations in the northeastern and north central United States. Results showed that the Dutch movable tray system and the flood floor system were most profitable and least risky for small potted plant and bedding crop flat production, respectively. The trough bench system was least favorable because its profitability was low and highly volatile.Risk and Uncertainty,

    Transmission Planning Process and Opportunities for Utility-Scale Solar Engagement within the Western Electricity Coordinating Council (WECC)

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    This report is a primer for solar developers who wish to engage directly in expediting the regulatory process and removing market barriers related to policy and planning. Market barriers unrelated to technology often limit the expansion of utility-scale solar power, even in areas with exceptional resource potential. Many of these non-technical barriers have to do with policy, regulation, and planning, and hardly ever do they resolve themselves in a timely fashion. In most cases, pre-emptive intervention by interested stakeholders is the easiest way to remove/address such barriers, but it requires knowing how to navigate the institutional waters of the relevant agencies and boards. This report is a primer for solar developers who wish to engage directly in expediting the regulatory process and removing market barriers related to policy and planning. It focuses on the Western Interconnection (WI), primarily because the quality of solar resources in the Southwest makes utility-scale concentrating solar power (CSP) and photovoltaics (PV) economically feasible, and because the relevant institutions have evolved in a way that has opened up opportunities for removing non-technical market barriers. Developers will find in this report a high-level field manual to identify the venues for mitigating and possibly eliminating systemic market obstacles and ensuring that the economic playing field is reasonably level. Project-specific issues such as siting for transmission and generation resources are beyond the scope of this report. Instead, the aim is to examine issues that pervasively affect all utility-scale PV and CSP in the region regardless of where the project may be. While the focus is on the WI, many of the institutions described here also have their counterparts in the Eastern and the Texas interconnections. Specifically, this report suggests a number of critical engagement points relating to generation and transmission planning

    Linking routinely collected social work, education and health data to enable monitoring of the health and health care of school-aged children in state care (‘looked after children’) in Scotland: a national demonstration project

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    Background and objectives: Children in state care (‘looked after children’) have poorer health than children who are not looked after. Recent developments in Scotland and elsewhere have aimed to improve services and outcomes for looked after children. Routine monitoring of the health outcomes of looked after children compared to those of their non-looked after peers is currently lacking. Developing capacity for comparative monitoring of population based outcomes based on linkage of routinely collected administrative data has been identified as a priority. To our knowledge there are no existing population based data linkage studies providing data on the health of looked after and non-looked after children at national level. Smaller scale studies that are available generally provide very limited information on linkage methods and hence do not allow scrutiny of bias that may be introduced through the linkage process. Study design and methods: National demonstration project testing the feasibility of linking routinely collected looked after children, education, and health data. Participants: All children in publicly funded school in Scotland in 2011/12. Results: Linkage between looked after children data and the national pupil census classified 10,009 (1.5%) and 1,757 (0.3%) of 670,952 children as, respectively, currently and previously looked after. Recording of the unique pupil identifier (Scottish Candidate Number, SCN) on looked after children returns is incomplete, with 66% of looked after records for 2011/12 for children of possible school age containing a valid SCN. This will have resulted in some under-ascertainment of currently and, particularly, previously looked after children within the general pupil population. Further linkage of the pupil census to the NHS Scotland master patient index demonstrated that a safe link to the child’s unique health service (Community Health Index, CHI) number could be obtained for a very high proportion of children in each group (94%, 95%, and 95% of children classified as currently, previously, and non-looked after respectively). In general linkage rates were higher for older children and those living in more affluent areas. Within the looked after group, linkage rates were highest for children with the fewest placements and for those in permanent fostering. Conclusions: This novel data linkage demonstrates the feasibility of monitoring population based health outcomes of school aged looked after and non-looked after children using linked routine administrative data. Improved recording of the unique pupil identifier number on looked after data returns would be beneficial. Extending the range of personal identifiers on looked after children returns would enable linkage to health data for looked after children who are not in publicly funded schooling (i.e. those who are pre- or post-school, home schooled, or in independent schooling)

    Macrostate Data Clustering

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    We develop an effective nonhierarchical data clustering method using an analogy to the dynamic coarse graining of a stochastic system. Analyzing the eigensystem of an interitem transition matrix identifies fuzzy clusters corresponding to the metastable macroscopic states (macrostates) of a diffusive system. A "minimum uncertainty criterion" determines the linear transformation from eigenvectors to cluster-defining window functions. Eigenspectrum gap and cluster certainty conditions identify the proper number of clusters. The physically motivated fuzzy representation and associated uncertainty analysis distinguishes macrostate clustering from spectral partitioning methods. Macrostate data clustering solves a variety of test cases that challenge other methods.Comment: keywords: cluster analysis, clustering, pattern recognition, spectral graph theory, dynamic eigenvectors, machine learning, macrostates, classificatio

    Integrating Variable Renewable Energy: Challenges and Solutions

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    In the U.S., a number of utilities are adopting higher penetrations of renewables, driven in part by state policies. While power systems have been designed to handle the variable nature of loads, the additional supply-side variability and uncertainty can pose new challenges for utilities and system operators. However, a variety of operational and technical solutions exist to help integrate higher penetrations of wind and solar generation. This paper explores renewable energy integration challenges and mitigation strategies that have been implemented in the U.S. and internationally, including forecasting, demand response, flexible generation, larger balancing areas or balancing area cooperation, and operational practices such as fast scheduling and dispatch

    GPR35 as a Novel Therapeutic Target

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    G protein-coupled receptors (GPCRs) remain the best studied class of cell surface receptors and the most tractable family of proteins for novel small molecule drug discovery. Despite this, a considerable number of GPCRs remain poorly characterized and in a significant number of cases, endogenous ligand(s) that activate them remain undefined or are of questionable physiological relevance. GPR35 was initially discovered over a decade ago but has remained an “orphan” receptor. Recent publications have highlighted novel ligands, both endogenously produced and synthetic, which demonstrate significant potency at this receptor. Furthermore, evidence is accumulating which highlights potential roles for GPR35 in disease and therefore, efforts to characterize GPR35 more fully and develop it as a novel therapeutic target in conditions that range from diabetes and hypertension to asthma are increasing. Recently identified ligands have shown marked species selective properties, indicating major challenges for future drug development. As we begin to understand these issues, the continuing efforts to identify novel agonist and antagonist ligands for GPR35 will help to decipher its true physiological relevance; translating multiple assay systems in vitro, to animal disease systems in vivo and finally to man

    Fe XI emission lines in a high resolution extreme ultraviolet spectrum obtained by SERTS

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    New calculations of radiative rates and electron impact excitation cross sections for Fe XI are used to derive emission line intensity ratios involving 3s^23p^4 - 3s^23p^33d transitions in the 180-223 A wavelength range. These ratios are subsequently compared with observations of a solar active region, obtained during the 1995 flight Solar EUV Research Telescope and Spectrograph (SERTS). The version of SERTS flown in 1995 incorporated a multilayer grating that enhanced the instrumental sensitivity for features in the 170 - 225 A wavelength range, observed in second-order between 340 and 450 A. This enhancement led to the detection of many emission lines not seen on previous SERTS flights, which were measured with the highest spectral resolution (0.03 A) ever achieved for spatially resolved active region spectra in this wavelength range. However, even at this high spectral resolution, several of the Fe XI lines are found to be blended, although the sources of the blends are identified in the majority of cases. The most useful Fe XI electron density diagnostic line intensity ratio is I(184.80 A)/I(188.21 A). This ratio involves lines close in wavelength and free from blends, and which varies by a factor of 11.7 between N_e = 10^9 and 10^11 cm^-3, yet shows little temperature sensitivity. An unknown line in the SERTS spectrum at 189.00 A is found to be due to Fe XI, the first time (to our knowledge) this feature has been identified in the solar spectrum. Similarly, there are new identifications of the Fe XI 192.88, 198.56 and 202.42 A features, although the latter two are blended with S VIII/Fe XII and Fe XIII, respectively.Comment: 21 pages, 9 gigures, accepted for publication in the Astrophysical Journa

    Proposed Metering and Instrumentation Monitoring and Analysis Plan and Budget: Alamo Community College District

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    The purpose of this overview is to outline the metering points that will be monitored by the Energy Systems Laboratory (ESL). At three of the campuses, Alamo Community College District (ACCD) has a central energy management system (EMS) installed that has the capability to record energy data. It is ESL's intent to utilize this system to collect data for energy monitoring and commissioning purposes. Since ACCD does not monitor gas consumption, ESL would like to incorporate gas metering into the current EMS. ESL may recommend upgrading some or all of the existing Energy Management System's software and client PC workstations (these hardware/software upgrades are not included in this budget), hi order for ESL to link into the existing EMS, it will be necessary to install additional software (PCAnywhere) or equipment (mainly another PC workstation) near the existing EMS computer terminals. ESL would also like Ethernet lines connected to the PC workstation so the system could be accessed via Internet. Software development will be needed to extract and format the existing EMS data sequence, push the data to ESL's network and load it into ESL's databases

    Reducing soil fertility to enable ecological restoration: A new method to test the efficacy of Full-Inversion Tillage

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    Ecological restoration of high-quality, semi-natural communities of conservation value on ex-arable soils with raised fertility has been a major problem in northern Europe. One suggested way of tackling this problem is to use Full-Inversion Tillage (FIT) where the fertile top-soil is moved below infertile sub-surface layers. This should provide infertile conditions at least in the short- to medium-term for the establishment of communities that require these conditions. Here, we pioneer a rigorous test of the efficacy of this approach. Our new method, using Principal Response Curves (PRCs), overcomes the difficulty in testing for change in soil physico-chemical properties down soil profiles with the inherent problem of autocorrelations between soil layers. Principal Response Curves (PRCs) is a multivariate technique, usually used to test for effects of treatment effects through time on a community matrix. We propose an extension of their use for the multivariate analysis of properties down a soil-depth profile. We tested the effects of FIT in two contrasting soils, before and after treatment. In a clay loam soil, FIT was effective in reducing the soil fertility in the surface 12 cm. Indeed the soil available P concentration, a key variable, was more than halved in the surface layers, and was below the lowest literature target threshold for the establishment of semi-natural grassland. In contrast, in the sandy soil, soil properties increased throughout the profile after FIT, primarily because of the pre-treatment nutrient distribution within the soil. Before FIT treatment, the maximum concentrations of most measured variables were at mid-depth and FIT redistributed these to the surface and bottom layers. Our results demonstrate the potential for FIT in ecological restoration, but indicate that its efficacy depends on soil type and the site history. We recommend that in future a pre-treatment assessment of soil properties with depth is undertaken before FIT is implemented, and that afterwards our PRC approach can be used to test efficacy immediately after treatment, and has the potential for measuring soil resilience to perturbation through time
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