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Full-Text Articles in Physical Sciences and Mathematics

A Gis Approach For Estimating Optimal Sites For Grid-Connected Photovoltaic (Pv) Cells In Nebraska, Tomotoshi Funabashi Dec 2011

A Gis Approach For Estimating Optimal Sites For Grid-Connected Photovoltaic (Pv) Cells In Nebraska, Tomotoshi Funabashi

Department of Environmental Studies: Undergraduate Student Theses

In the context of rising energy concerns and increased spotlight on solar energy, this study examines and draws attention to the state of mid potential sunlight. The purpose of this study is to estimate the optimal sites for grid-connected photovoltaic cells in Nebraska, which is ranked 13th nationally in terms of insolation potential. Five factors – insolation potential, adjacency to roads, accessibility to grid, topography, and acreage – are examined with the use of Geographic Information System (GIS). Insolation potential was quantitatively analyzed by averaging, plotting, and interpolating the 20 years of datasets recoded at 28 weather stations of High …


Guiding The Experimental Discovery Of Magnesium Alloys, Richard H. Taylor, Gus L. W. Hart, Stefano Curtarolo Aug 2011

Guiding The Experimental Discovery Of Magnesium Alloys, Richard H. Taylor, Gus L. W. Hart, Stefano Curtarolo

Faculty Publications

Magnesium alloys are among the lightest structural materials known and are of considerable technological interest. To develop superior magnesium alloys, experimentalists must have a thorough understanding of the concentration-dependent precipitates that form in a given system, and hence, the thermodynamic stability of crystal phases must be determined. This information is often lacking but can be supplied by first-principles methods. Within the high-throughput framework, AFLOW, T = 0 K ground-state predictions are made by scanning a large set of known candidate structures for thermodynamic (formation energy) minima. The following 34 systems are investigated: AlMg, AuMg, CaMg, CdMg, CuMg, FeMg , GeMg, …


Trends Of Wind And Wind Power Over The Coterminous United States, Eric M. Holt Mar 2011

Trends Of Wind And Wind Power Over The Coterminous United States, Eric M. Holt

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The trends of wind and wind power at a typical wind turbine hub height (80 m) are analyzed using the North American Regional Reanalysis (NARR) dataset for 1979-2009. Based upon the wind speeds at NARR’s vertical layers right above and below the 80 m level, the wind speeds at 80 m are estimated using two methods assuming the wind profile respectively as linear and power-law distribution with respect to the altitude in the lower boundary layer. Furthermore, we calculate the following variables at 80 m that are needed for the estimation and interpretation of wind power: the air density, zonal …


Reduction Of Benzylidene Dibenzo[ A, D ]Cycloheptenes: Over-Reduction Of Antiaromatic Dianions To Aromatic Tetraanions, Blakely Tresca, Macdonald Higbee, Nancy S. Mills Jan 2011

Reduction Of Benzylidene Dibenzo[ A, D ]Cycloheptenes: Over-Reduction Of Antiaromatic Dianions To Aromatic Tetraanions, Blakely Tresca, Macdonald Higbee, Nancy S. Mills

Chemistry Faculty Research

The antiaromaticity of a series of dianions of p-substituted benzylidene dibenzo[a,d]cycloheptenes was examined through calculated measures of antiaromaticity. The nucleus-independent chemical shifts (NICS) and magnetic susceptibility exaltation both showed substantial antiaromatic character in the benzannulated tropylium anion. When the antiaromaticity was normalized for the area of the ring, these tropylium anions were shown to be among the most antiaromatic anions in the chemical literature. Attempts to make the dianion through reduction with lithium or potassium gave the tetraanion as the only species observable in the (1)H NMR spectrum. Quench of the reaction mixture with trimethylsilyl chloride or D(2)O confirmed the …


Potential Reduction In Energy Use From A High Speed Rail Network In Australia, Philip Laird Jan 2011

Potential Reduction In Energy Use From A High Speed Rail Network In Australia, Philip Laird

Faculty of Informatics - Papers (Archive)

High Speed Rail or HSR with electric passenger trains using steel wheels on steel rails with maximum operating speeds of 250km/h or more is now operational in 12 countries. It is now under review in Australia. The paper considers energy use on the 10 top routes of the Melbourne-Sydney and Sydney-Brisbane corridors and finds that HSR was in place by 2020, HSR could reduce the use of aviation fuel by over 450 million litres each year. External costs and Sydney airport issues are also noted.


The Carbon Footprint Associated With Water Management Policy Options In The Las Vegas Valley, Nevada, Eleeja Shrestha, Sajjad Ahmad, Walter Johnson, Jacimaria R. Batista Jan 2011

The Carbon Footprint Associated With Water Management Policy Options In The Las Vegas Valley, Nevada, Eleeja Shrestha, Sajjad Ahmad, Walter Johnson, Jacimaria R. Batista

Civil and Environmental Engineering and Construction Faculty Research

A system dynamics model was developed to estimate the carbon dioxide (CO2) emissions associated with conveyance of water from the water source to the distribution laterals of the Las Vegas Valley. In addition, the impact of several water management policies, including water conservation, reuse, and population growth rate change was evaluated. The results show that, at present, nearly 0.53 million metric tons of CO2 emissions per year are released due to energy use for water conveyance in distribution laterals of the Valley from Lake Mead, located 32.2 km (20 miles) southeast of the Las Vegas at an …


A Primer Of Swarm Equilibria, Andrew J. Bernoff, Chad M. Topaz Jan 2011

A Primer Of Swarm Equilibria, Andrew J. Bernoff, Chad M. Topaz

All HMC Faculty Publications and Research

We study equilibrium configurations of swarming biological organisms subject to exogenous and pairwise endogenous forces. Beginning with a discrete dynamical model, we derive a variational description of the corresponding continuum population density. Equilibrium solutions are extrema of an energy functional and satisfy a Fredholm integral equation. We find conditions for the extrema to be local minimizers, global minimizers, and minimizers with respect to infinitesimal Lagrangian displacements of mass. In one spatial dimension, for a variety of exogenous forces, endogenous forces, and domain configurations, we find exact analytical expressions for the equilibria. These agree closely with numerical simulations of the underlying …


Chemically Activated Reactions On The C7h5 Energy Surface: Propargyl + Diacetylene, I-C5h3 + Acetylene, And N-C5h3 + Acetylene, Gabriel Da Silva, Adam J. Trevitt Jan 2011

Chemically Activated Reactions On The C7h5 Energy Surface: Propargyl + Diacetylene, I-C5h3 + Acetylene, And N-C5h3 + Acetylene, Gabriel Da Silva, Adam J. Trevitt

Faculty of Science - Papers (Archive)

This study uses computational chemistry and statistical reaction rate theory to investigate the chemically activated reaction of diacetylene (butadiyne, C4H2) with the propargyl radical (C •H2CCH) and the reaction of acetylene (C 2H2) with the i-C5H3 (CH 2CCCC•H) and n-C5H3 (CHCC •HCCH) radicals. A detailed G3SX-level C7H 5 energy surface demonstrates that the C3H3 + C4H2 and C5H3 + C2H 2 addition reactions proceed with moderate barriers, on the order of 10 to 15 kcal mol-1, and form activated open-chain C 7H5 species that can isomerize to the fulvenallenyl radical with the highest barrier still significantly below the entrance channel …