607 research outputs found
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WindPACT Turbine Design Scaling Studies Technical Area 3 -- Self-Erecting Tower and Nacelle Feasibility: March 2000--March 2001
The United States Department of Energy (DOE), through the National Renewable Energy Laboratory (NREL), has implemented the Wind Partnerships for Advanced Component Technologies (WindPACT) program to explore advanced technologies for improving the reliability and cost-effectiveness of wind energy technology. Global Energy Concepts (GEC) prepared this report on self-erecting towers as part of the WindPACT program. The objectives of the work were to identify potential methods for erecting wind turbine towers without the use of large conventional cranes, establish the most promising methods, and compare the costs of the most promising methods to the costs of conventional cranes
National Security Risks? Uncertainty, Austerity and Other Logics of Risk in the UK government’s National Security Strategy
Risk scholars within Security studies have argued that the concept of security has gone through a fundamental transformation away from a threat-based conceptualisation of defence, urgency and exceptionality to one of preparedness, precautions and prevention of future risks, some of which are calculable, others of which are not. This article explores whether and how the concept of security is changing due to this ‘rise of risk’, through a hermeneutically grounded conceptual and discourse analysis of the United Kingdom government’s national security strategy (NSS) from 1998 to 2011. We ask how risk-security language is employed in the NSS; what factors motivate such discursive shifts; and what, if any, consequences of these shifts can be discerned in UK national security practices. Our aim is twofold: to better understand shifts in the security understandings and policies of UK authorities; and to contribute to the conceptual debate on the significance of the rise of risk as a component of the concept of security
Using Wind To Power a Groundwater Circulation Well—Preliminary Results
In areas of the country where the U.S. Department of Energy has classified the available wind resources as Class 3 or greater, the use of wind turbines to provide power to relatively small remediation systems such as groundwater circulation wells may be technically and economically feasible. Groundwater circulation wells are a good candidate technology to couple with renewable energy, because the remediation system removes contamination from the subject aquifer with no net loss of the groundwater resource, while the wind turbine does not create potentially harmful air emissions. Wind data collected in the vicinity of the former Nebraska Ordnance Plant Superfund site were used to select a wind turbine system to provide a portion of the energy necessary to power a groundwater circulation well located in an area of high trichloroethylene groundwater contamination. Because utility power was already installed at the remediation system, a 10 kW grid inter-tie wind turbine system supplements the utility system without requiring batteries for energy storage. The historical data from the site indicate that the quantity of energy purchased correlates poorly with the quantity of groundwater treated. Preliminary data from the wind turbine system indicate that the wind turbine provides more energy than the remediation system treatment components and the well submersible pump require on a monthly average. The preliminary results indicate that the coupling of wind turbines and groundwater circulation wells may be an attractive alternative in terms of the system operation time, cost savings, and contaminant mass removal
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Wind turbine reliability :understanding and minimizing wind turbine operation and maintenance costs.
Wind turbine system reliability is a critical factor in the success of a wind energy project. Poor reliability directly affects both the project's revenue stream through increased operation and maintenance (O&M) costs and reduced availability to generate power due to turbine downtime. Indirectly, the acceptance of wind-generated power by the financial and developer communities as a viable enterprise is influenced by the risk associated with the capital equipment reliability; increased risk, or at least the perception of increased risk, is generally accompanied by increased financing fees or interest rates. This paper outlines the issues relevant to wind turbine reliability for wind turbine power generation projects. The first sections describe the current state of the industry, identify the cost elements associated with wind farm O&M and availability and discuss the causes of uncertainty in estimating wind turbine component reliability. The latter sections discuss the means for reducing O&M costs and propose O&M related research and development efforts that could be pursued by the wind energy research community to reduce cost of energy
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Blade system design studies volume II : preliminary blade designs and recommended test matrix.
As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) program, Global Energy Concepts, LLC is performing a Blade System Design Study (BSDS) concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. The BSDS Volume I project report addresses issues and constraints identified to scaling conventional blade designs to the megawatt size range, and evaluated candidate materials, manufacturing and design innovations for overcoming and improving large blade economics. The current report (Volume II), presents additional discussion of materials and manufacturing issues for large blades, including a summary of current trends in commercial blade manufacturing. Specifications are then developed to guide the preliminary design of MW-scale blades. Using preliminary design calculations for a 3.0 MW blade, parametric analyses are performed to quantify the potential benefits in stiffness and decreased gravity loading by replacement of a baseline fiberglass spar with carbon-fiberglass hybrid material. Complete preliminary designs are then presented for 3.0 MW and 5.0 MW blades that incorporate fiberglass-to-carbon transitions at mid-span. Based on analysis of these designs, technical issues are identified and discussed. Finally, recommendations are made for composites testing under Part I1 of the BSDS, and the initial planned test matrix for that program is presented
Running Past the Trees: Facing Childhood and Adolescence in Iowa\u27s Cedar Valley
This anthology is the result of a service-learning project supported by The Facing Project. Students enrolled in Two-Dimensional Concepts, a foundations art course at the University of Northern Iowa, and K-12 authors at the Waterloo Writing Project collaborated over the course of a semester through shared stories, conversations, and illustrations. The authors provided stories of their experiences and memories growing up in the Cedar Valley and were partnered with first year UNI art students who took inspiration from the authors\u27 writings to create accompanying illustrations.https://scholarworks.uni.edu/sli_trees/1000/thumbnail.jp
Validation of a microsimulation of the port of Dover
Modelling and simulating the traffic of heavily used but secure environments such as seaports and airports is of increasing importance. Errors made when simulating these environments can have long standing economic, social and environmental implications. This paper discusses issues and problems that may arise when designing a simulation strategy. Data for the Port is presented, methods for lightweight vehicle assessment that can be used to calibrate and validate simulations are also discussed along with a diagnosis of overcalibration issues. We show that decisions about where the intelligence lies in a system has important repercussions for the reliability of system statistics. Finally, conclusions are drawn about how microsimulations can be moved forward as a robust planning tool for the 21st century
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Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery
An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated
Bures and Statistical Distance for Squeezed Thermal States
We compute the Bures distance between two thermal squeezed states and deduce
the Statistical Distance metric. By computing the curvature of this metric we
can identify regions of parameter space most sensitive to changes in these
parameters and thus lead to optimum detection statistics.Comment: 15 pages, 1 figure (not included - obtain from Author) To appear in
Journal of Physics
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