1,304 research outputs found

    Solar microclimatology

    Get PDF
    It has become apparent in recent years that solar energy can be used for electric power production by several methods. Because of the diffuse nature of the solar insolation, the area involved in any central power plant design can encompass several square miles. A detailed design of these large area collection systems will require precise knowledge of the local solar insolation. Detailed information will also be needed concerning the temporal nature of the insolation and the local spatial distribution. Therefore, insolation data was collected and analyzed for a network of sensors distributed over an area of several square kilometers in Arizona. The analyses of this data yielded probability distributions of cloud size, velocity, and direction of motion which were compared with data obtained from the National Weather Service. Microclimatological analyses were also performed for suitable modeling parameters pertinent to large scale electric power plant design. Instrumentation used to collect the data is described

    1998 EASTERN ONTARIO ICE STORM MAPLE PRODUCERS' SURVEY: SUMMARY AND RESULTS

    Get PDF
    In August, 1999, a telephone survey of maple producers in eastern Ontario was conducted in order to gather information on the changes in their operations since the 1998 ice storm. This paper presents the findings of the survey. The results will be used in a larger study to examine the economic impact of the ice storm on maple producers in this region.Crop Production/Industries, Resource /Energy Economics and Policy,

    An Evolutionary Algorithm to Generate Real Urban Traffic Flows

    Get PDF
    In this article we present a strategy based on an evolutionary algorithm to calculate the real vehicle ows in cities according to data from sensors placed in the streets. We have worked with a map imported from OpenStreetMap into the SUMO traffic simulator so that the resulting scenarios can be used to perform different optimizations with the confidence of being able to work with a traffic distribution close to reality. We have compared the results of our algorithm to other competitors and achieved results that replicate the real traffic distribution with a precision higher than 90%.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by project number 8.06/5.47.4142 in collaboration with the VSB-Technical University of Ostrava and Universidad de Málaga UMA/FEDER FC14-TIC36, programa de fortalecimiento de las capacidades de I+D+i en las universidades 2014-2015, de la Consejería de Economía, Innovación, Ciencia y Empleo, cofinanciado por el fondo europeo de desarrollo regional (FEDER). Also, partially funded by the Spanish MINECO project TIN2014-57341-R (http://moveon.lcc.uma.es). The authors would like to thank the FEDER of European Union for financial support via project Movilidad Inteligente: Wi-Fi, Rutas y Contaminación (maxCT) of the "Programa Operativo FEDER de Andalucía 2014-2020. We also thank all Agency of Public Works of Andalusia Regional Government staff and researchers for their dedication and professionalism. Daniel H. Stolfi is supported by a FPU grant (FPU13/00954) from the Spanish Ministry of Education, Culture and Sports

    Prevalence and correlates of cryptococcal antigen positivity among AIDS patients--United States, 1986-2012.

    Get PDF
    Cryptococcal meningitis (CM) is one of the leading opportunistic infections associated with human immunodeficiency virus (HIV) infection. The worldwide burden of CM among persons living with HIV/acquired immunodeficiency syndrome (AIDS) was estimated in 2009 to be 957,900 cases, with approximately 624,700 deaths annually. The high burden of CM globally comes despite the fact that cryptococcal antigen (CrAg) is detectable weeks before the onset of symptoms, allowing screening for cryptococcal infection and early treatment to prevent CM and CM-related mortality (2). However, few studies have been conducted in the United States to assess the prevalence of cryptococcal infection. To quantify the prevalence of undiagnosed cryptococcal infection in HIV-infected persons in the United States during 1986-2012, stored sera from 1,872 participants in the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study with CD4 T-cell counts <100 cells/µL were screened for CrAg, using the CrAg Lateral Flow Assay (LFA) (Immy, Inc.). This report describes the results of that analysis, which indicated the overall prevalence of CrAg positivity in this population to be 2.9% (95% confidence interval [CI] = 2.2%-3.7%)

    Intercomparison of ground-based and space solar flux measurements

    Get PDF
    Detailed temporal measurements of the solar flux at one location are performed. These data are then analyzed and compared to the potential of space measurements which allow one to consider the flux falling on areas of the earth. An important result of the research is that the temporal characteristics of the flux in the presence of a real atmosphere would be difficult to obtain from space and that the variations in the flux can be highly significant in regard to most solar conversion schemes. The detailed results of the research are presented. The instruments developed to separate the direct and scattered solar flux, the computer analysis methods developed, and the results of the research, presented as both graphical and tabular data, are discussed

    Analyzing Math-to-Mastery through Brief Experimental Analysis

    Get PDF
    The current study evaluated the effectiveness of individualized math-to-mastery (MTM) interventions, selected though brief experimental analysis (BEA), at increasing math fluency skills for 3 elementary-aged females. As MTM has only been investigated as a multicomponent intervention, the present study utilized BEA to identify those specific components which led to math skills gains in the most efficient manner possible. BEA results indicated that for 2 of 3 participants only a partial MTM intervention was necessary to prompt fluency gains, while the entire intervention was the most effective for the third. During extended analysis all 3 participants displayed math skills gains above those seen during repeated baseline assessments. Results are discussed in terms of further refining MTM through BEA procedures so as to individually target math skill deficits by considering both intervention effectiveness and efficiency

    Swim Speed, Behavior, and Movement of North Atlantic Right Whales (\u3cem\u3eEubalaena glacialis\u3c/em\u3e) in Coastal Waters of Northeastern Florida, USA

    Get PDF
    In a portion of the coastal waters of northeastern Florida, North Atlantic right whales (Eubalaena glacialis) occur close to shore from December through March. These waters are included within the designated critical habitat for right whales. Data on swim speed, behavior, and direction of movement – with photo-identification of individual whales – were gathered by a volunteer sighting network working alongside experienced scientists and supplemented by aerial observations. In seven years (2001–2007), 109 tracking periods or “follows” were conducted on right whales during 600 hours of observation from shore-based observers. The whales were categorized as mother-calf pairs, singles and non-mother-calf pairs, and groups of 3 or more individuals. Sample size and amount of information obtained was largest for mother-calf pairs. Swim speeds varied within and across observation periods, individuals, and categories. One category, singles and non mother-calf pairs, was significantly different from the other two – and had the largest variability and the fastest swim speeds. Median swim speed for all categories was 1.3 km/h (0.7 kn), with examples that suggest swim speeds differ between within-habitat movement and migration-mode travel. Within-habitat right whales often travel back-and-forth in a north-south, along-coast, direction, which may cause an individual to pass by a given point on several occasions, potentially increasing anthropogenic risk exposure (e.g., vessel collision, fishing gear entanglement, harassment). At times, mothers and calves engaged in lengthy stationary periods (up to 7.5 h) that included rest, nursing, and play. These mother-calf interactions have implications for communication, learning, and survival. Overall, these behaviors are relevant to population status, distribution, calving success, correlation to environmental parameters, survey efficacy, and human-impacts mitigation. These observations contribute important parameters to conservation biology, predictive modeling, and management. However, while we often search for predictions, patterns, and means, the message here is also about variability and the behavioral characteristics of individual whales

    Microwave Dielectric Loss at Single Photon Energies and milliKelvin Temperatures

    Full text link
    The microwave performance of amorphous dielectric materials at very low temperatures and very low excitation strengths displays significant excess loss. Here, we present the loss tangents of some common amorphous and crystalline dielectrics, measured at low temperatures (T < 100 mK) with near single-photon excitation energies, using both coplanar waveguide (CPW) and lumped LC resonators. The loss can be understood using a two-level state (TLS) defect model. A circuit analysis of the half-wavelength resonators we used is outlined, and the energy dissipation of such a resonator on a multilayered dielectric substrate is considered theoretically.Comment: 4 pages, 3 figures, submitted to Applied Physics Letter
    • …
    corecore