Bivariate Hermite Interpolation and Numerical Curves

AbstractIn this paper, Hermite interpolation by bivariate algebraic polynomials of total degree ⩽nis considered. The interpolation parameters are the values of a function and its partial derivatives up to some ordernν−1 at the nodeszν=(xν, yν),ν=1, …, s, wherenνis the multiplicity ofzν. The sequence N={n1, …, ns; n} of multiplicities associated with the degree of interpolating polynomials is investigated. Some results of the paper were announced in [GHS93]

Neutron capture-induced silicon nuclear recoils for dark matter and CEν\nuNS

Following neutron capture in a material there will be prompt nuclear recoils in addition to the gamma cascade. The nuclear recoils that are left behind in materials are generally below 1\,keV and therefore in the range of interest for dark matter experiments and CE$\nu$NS studies--both as backgrounds and calibration opportunities. Here we obtain the spectrum of prompt nuclear recoils following neutron capture for silicon.Comment: 8 pages, 9 figures, 1 tabl

Wind Power Opportunities in St. Thomas, USVI: A Site-Specific Evaluation and Analysis

This NREL technical report utilizes a development framework originated by NREL and known by the acronym SROPTTC to assist the U.S. Virgin Islands in identifying and understanding concrete opportunities for wind power development in the territory. The report covers each of the seven components of the SROPTTC framework: Site, Resource, Off-take, Permitting, Technology, Team, and Capital as they apply to wind power in the USVI and specifically to a site in Bovoni, St. Thomas. The report concludes that Bovoni peninsula is a strong candidate for utility-scale wind generation in the territory. It represents a reasonable compromise in terms of wind resource, distance from residences, and developable terrain. Hurricane risk and variable terrain on the peninsula and on potential equipment transport routes add technical and logistical challenges but do not appear to represent insurmountable barriers. In addition, integration of wind power into the St. Thomas power system will present operational challenges, but based on experience in other islanded power systems, there are reasonable solutions for addressing these challenges

Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling

We investigate the electromagnetic field generated by a point charge moving along a helical trajectory inside a circular waveguide with conducting walls filled by homogeneous dielectric. The parts corresponding to the radiation field are separated and the formulae for the radiation intensity are derived for both TE and TM waves. It is shown that the main part of the radiated quanta is emitted in the form of the TE waves. Various limiting cases are considered. The results of the numerical calculations show that the insertion of the waveguide provides an additional mechanism for tuning the characteristics of the emitted radiation by choosing the parameters of the waveguide and filling medium.Comment: 17 pages, 9 figures, discussion, graphs, and references adde

Active Power Controls from Wind Power: Bridging the Gaps

This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design

First International Workshop on Grid Simulator Testing of Wind Turbine Drivetrains: Workshop Proceedings

This report summarizes the proceedings of the First International Workshop on Grid Simulator Testing of Wind Turbine Drivetrains, held from June 13 to 14, 2013, at the National Renewable Energy Laboratory's National Wind Technology Center, located south of Boulder, Colorado. The workshop was sponsored by the U.S. Department of Energy and cohosted by the National Renewable Energy Laboratory and Clemson University under ongoing collaboration via a cooperative research and development agreement. The purpose of the workshop was to provide a forum to discuss the research, testing needs, and state-of-the-art apparatuses involved in grid compliance testing of utility-scale wind turbine generators. This includes both dynamometer testing of wind turbine drivetrains ('ground testing') and field testing grid-connected wind turbines. Four sessions followed by discussions in which all attendees of the workshop were encouraged to participate comprised the workshop

Wind Resource Development Project for Armenia

Armenia has few proven reserves of natural energy and is dependent on long, unreliable transport lines for oil and gas. Preliminary studies indicate that the wind energy potential in Armenia is more than 500 megawatts (MW), assuming a reasonable fraction of 10% of the land area in the high-wind zones. Over the long term, the Armenian government intends to meet 8%--10% of its electric consumption needs by grid-connected wind turbines. The goals of this project are to enhance Armenia's energy security, mitigate the environmental damage of conventional sources of energy, reduce future carbon dioxide emissions, build an environmentally sound and sustainable model for economic development, and promote trade between the U.S. and Armenia. The project is being funded by the Cafesjian Family Foundation, a private foundation based in the United States in Naples, Florida, with the participation of Ecotrade, Inc. of Glendale, California. The National Renewable Energy Laboratory (NREL) is providing technical assistance. As part of the wind energy development project, the authors conducted a preliminary wind-energy resource assessment for some regions in Armenia. This activity provided valuable information needed to facilitate the commercialization of wind farms in Armenia and to lay the groundwork for subsequent wind resource activities. This paper presents the wind resource monitoring results (1999--2000) for the candidate site. Preliminary assessment identified areas with good-to-excellent wind resource potential