1,721,019 research outputs found
Implementing gridshare technology in rural Bhutan: analyzing effects on electrical brownouts and assessing community acceptance
Get PDFThis thesis evaluates the effectiveness of the pilot installation of GridShares, demand-side management devices designed to reduce the severity of brownouts on isolated, power-limited mini-grids. The low voltages associated with brownouts cause lights to dim and resistance heating appliances, such as rice cookers and water boilers, to function poorly. GridShare devices and the accompanying education program were designed by a team consisting of the author and fellow undergraduate and graduate students from Humboldt State University. In coordination with partner organizations, the team built and installed 90 GridShares in all households and businesses connected to a 40 kW village micro-hydroelectric system in Rukubji, Bhutan in July 2011. Prior to the installation, residents of Rukubji faced routine brownouts due to the use of high-wattage appliances to cook breakfast and dinner. Through a combination of education, indication and enforcement, the GridShare limited this peak demand while still enabling the use of these large appliances when excess energy was available. After the GridShare installation, the village experienced severe brownouts on 92% fewer days than in the prior year. Though the installation did not eliminate the brownout problem entirely, in household surveys, residents stated that the GridShares made the grid more predictable and provided information necessary for residents to make informed decisions regarding their electricity use. Additional data from electricity billing records, individual household data loggers and GridShare serial data provide further insight into the functioning of the system. Following the one-year pilot test agreement, the community of Rukubji decided by consensus to keep the GridShares installed, and the Bhutan Power Corporation continues to support the effort. This pilot project indicates that user-interactive demand-side management strategies, such as the GridShare, are effective at reducing brownouts on mini-grids.Thesis (M.S.)--Humboldt State University, Environmental Systems: Energy, Technology and Policy, 201
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Feasibility analysis of gasification for energy recovery from residual solid waste in Humboldt County
No full textThesis (M.S.)--Humboldt State University, Environmental Systems: Energy Technology and Policy, 2013This analysis investigates the feasibility of implementing a gasification system to process residual solid waste in Humboldt County. The Humboldt Waste Management Authority manages 70,000 tons of municipal solid waste annually, which is transported over 180 miles for landfill disposal. This makes the cost of waste management three times higher than the national average. \ud
Two alternative management scenarios were investigated as a way to reduce the cost and environmental impacts of waste disposal. This first scenario uses a solid waste material recovery facility to divert hazardous, recyclable, and compostable materials from the waste stream, landfilling only residual wastes. The second scenario locally processes separated residual waste for energy recovery using a gasification system. For this analysis, a plasma arc gasification system was selected from an evaluation of five companies offering a range of gasification technologies. \ud
The results of this analysis indicate that implementing these management systems could reduce greenhouse gas emissions by more than 60% (17,400 metric tCO2e/year). A material recovery facility could increase diversion up to 65% and reduce management costs by 5% (360,000/year) to 30% ($1,280,000/year) if electricity is sold at the higher renewable rate. This study demonstrates that developing waste as a resource is an opportunity to progress Humboldt County???s energy, environmental, and economic security
Analysis of low-cost testing methods for LED lumen maintenance of off-grid lighting products
No full textThesis (M.S.)--Humboldt State University, Environmental Resources Engineering, 2011Two low-cost test methods for measuring the lumen maintenance of off-grid lighting products, a box-photometer and a tube-photometer, were compared to a high-accuracy integrating sphere system in order to evaluate the measurement error of the low-cost testing devices. Results from this study indicate that the box- and tube-photometers can be used to accurately measure the relative change in light output of typical off-grid lighting products. The tube and box are simple and inexpensive to construct, and they are quicker and easier to use than an integrating sphere system. The box-photometer and tube-photometer are recommended for use in testing off-grid lighting products according to the Long-Term Lumen Degradation Test specified in Lighting Africa???s Quality Test Method and Initial Screening Method. The box???s strengths lie in its versatility and ease-of-use. The box-photometer can be used for testing product run-time and lumen maintenance, and a single measurement can be conducted in a matter of seconds by a minimally trained technician. The tube- \ud
photometer, while nearly as easy to use as the box, excels in terms of constructability, cost, and physical size. A tube-photometer can be built of basic materials that are widely available at very low cost. No specialized tools or skills are necessary to build the device. The tube-photometer is small, light and portable, allowing for easy storage and minimal space for operation.\ud
Results from this study indicate that a small degree of measurement error can result from improper use of the low-cost devices. Box-photometer measurements are susceptible to error caused by changes in the light source location and orientation, especially for highly directional and adjustable products. The tube-photometer is prone to small errors due to false identification of the maximum illuminance measurement. These errors, however, can be easily minimized by repetition of measurements and training test operators to use the equipment properly
Winter barley can serve as an economically feasible ethanol feedstock
No full textThesis (M.S.)--Humboldt State University, Environmental Systems: Energy, Environment, and Society, 2014Embargoed for one year from date added to Humboldt Digital Scholar (2014-05-29).Released from embargo June 2, 2015.Land resources are becoming progressively more constrained with increasing demands for food, feed, fiber, and now fuel production; developing strategies to intensify crop production without increasing the negative impacts on water, soil, and air resources are critical. Much of our best agricultural lands are dominated by corn-soybean rotations with winter fallow periods. There has been interest in diversifying and intensify production of the farm landscape to improve water quality. Winter cover crops are one strategy to reduce nutrient losses over winter, but they have not been widely adopted. Harvested cover crops, or double crops, of winter small grains are common in some regions. The objective of this thesis was to quantify the value of ecosystem services along with crop residues from winter double crops as a bioenergy feedstock, to assess their potential as incentives for deployment into the landscape. The biogeochemical model DayCent was used to quantify the impact of winter double crops on nitrate leaching, nitrous oxide emissions, and soil carbon. A range of values for these ecosystem services was then evaluated, along with biomass, as potential economic incentives to increase the economic returns for planting these crops. Reduction in nitrate leaching was the highest valued ecosystem service provided by the winter double crops, then soil carbon and N2O emissions. Although rye provided significant yield and ecosystem services, it was never economic and was the most expensive winter double crop. However it was found that in addition to significant value from ecosystem services with planting winter small grains, they also had lower breakeven prices and yields leading to greater potential as a bioenergy feedstock. Considering the sensitivity of double crop rotation economics to soybean yields, and that north of the 40th parallel, barley has less impact on soybean yields than wheat, establishment of a bioenergy market for biomass could provide significant incentive for wide spread planting of winter barley as a double crop in corn soybean rotations, and realize significant environmental benefits
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