• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 59
  • 24
  • 9
  • 9
  • 6
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 140
  • 22
  • 14
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Employment, economic fluctuations and job security

Diaz-Vasquez, Maria Del Pilar January 1997 (has links)
No description available.
2

In constant flux

Kuharik, Christian Bernard. January 2003 (has links)
Thesis (M.F.A.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains iv, 29 p. : col. ill. + video clip. Includes an injection system video clip. Vita. Includes abstract. Includes bibliographical references (p. 17).
3

The bloating of clays

Sharp, Everett Walter. January 1940 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1940. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed March 23, 2010) Includes bibliographical references (p. 31) and index (p. 32).
4

Simulating the Affects of Glutamatergic Afferents on the Firing Pattern of Midbrain Dopamine Neurons

Landry, Richard Spencer, Jr. 20 January 2006 (has links)
A computational model of a midbrain dopamine neuron was extended in this study to include a response to random excitatory afferent input by incorporating the receptor components AMPA and NMDA. In a diagonal band where average glutamatergic and tonic gabaergic input is roughly balanced, both single spike firing and bursting can be observed. Simulated SK channel block strengthens the correlation between pattern and rate and increases the number of spikes fired in bursts by increasing the spikes per burst. A simulated doubling of the AMPA/NMDA ratio leads to a frequency increase that becomes more prominent at high firing rates, and an increase in the percent spikes fired in bursts. Changes in pattern and rate are poorly correlated in the model. Manipulations of the neuron greatly depend on the background level of synaptic inputs, suggesting that interpretation of population data from dopamine neurons requires taking variability into account rather than averages.
5

Chip Firing and Fractional Chromatic Number of the Kneser Graph

Liao, Shih-kai 29 June 2004 (has links)
In this thesis we focus on the investigation of the relation between the the chip-firing and fractional coloring. Since chi_{f}(G)=inf {n/k : G is homomorphic to K(n,k)}, we find that G has an (n,k)-periodic sequence for some configuration if and only if G is homomorphic to K(n,k). Then we study the periodic configurations for the Kneser graphs. Finally, we try to evaluate the number of chips of the periodic configurations for K(n,k).
6

The evolution of a range of salt glaze teapots

Meanley, Peter January 1998 (has links)
No description available.
7

Energy ans exergy analysis of biomass co-firing in pulverized coal power generation

Mehmood, Shoaib 01 April 2011 (has links)
Biomass co-firing with coal exhibits great potential for large scale utilization of biomass energy in the near future. In the present work, energy and exergy analyses are carried out for a co-firing based power generation system to investigate the impacts of biomass cofiring on system performance and gaseous emissions of CO2, NOx, and SOx. The power generation system considered is a typical pulverized coal-fired steam cycle system, while four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel) and two coals (bituminous coal and lignite) are chosen for the analysis. System performance is evaluated in terms of important performance parameters for different combinations of fuel at different co-firing conditions and for the two cases considered. The results indicate that plant energy and exergy efficiencies decrease with increase of biomass proportion in the fuel mixture. The extent of decrease in energy and exergy efficiencies depends on specific properties of the chosen biomass types. The results also show that the increased fraction of biomass significantly reduces the net CO2 emissions for all types of selected biomass. However, gross CO2 emissions increase for all blends except bituminous coal/refuse derived fuel blend, lignite/chicken litter blend and lignite/refuse derived fuel blend. The reduction in NOx emissions depends on the nitrogen content of the biomass fuel. Likewise, the decrease in SOx emissions depends on the sulphur content of the biomass fuel. The most appropriate biomass in terms of NOx and SOx reduction is sawdust because of its negligible nitrogen and sulphur contents. / UOIT
8

Pseudonáhodné procházky a chip-firing games / Pseudorandom walks and chip firing games

Mittal, Parth January 2021 (has links)
We study two deterministic analogues of random walks. The first is the chip-firing game, a single player game played by moving chips around a directed graph, popularised by Björner and Lovász. We find an efficient simulation of boolean circuits and Turing machines using instances of the chip-firing game - after assigning a fixed strategy to the player. The second is the Propp machine, or the rotor router model, a quasirandom model intro- duced by Priezzhev. We improve results of Kijima et al. and show a bound of O(m) on the discrepancy of this process from a random walk on d-regular graphs with m edges. 1
9

Feasibility and Co-Benefits of Biomass Co-Firing: Case in Utah

Paudel, Bibek 01 May 2013 (has links)
This research examines the physical and economic feasibility of 5% biomass co-firing in the coal-fired power plants of Utah. Transportation models is used to find out the physical feasibility of 5% biomass co-firing, as well as locate the supply zone for each power plant that would minimize the transportation cost. Additional cost required for 5% biomass co-firing and the economic benefits associated with biomass co-firing are calculated. The additional cost required for 5% biomass co-firing is estimated to be $34.84 million. Previous studies on CO2 emission reduction are used to compute the economic benefit attain from CO2 reduction by selling carbon credits in the carbon trading market. Based on 2010 emission record in Utah, 5% biomass co-firing might reduce 0.71~2.13 million metric tons of CO2 and, in turn, bring the annual economic benefit of $11.37~$34.10 million assuming $16/ton of CO2 in the emission trading market. The regression model is used to find the relationship between PM emission and the human health damage. The regression results show that decreases in 1% of PM25 emission improves the human health in U.S. by 0.65%~0.67% in value. Five percent biomass co-firing generates annual economic benefits of $6.72~$9.93 million in Utah depending on the emission reduction scenarios. Note that these might not be the precise economic benefit from the biomass co-firing in Utah because elasticities estimated in the regression are expected to be lower in Utah. This is because most of power plants in Utah are located in open areas. Altogether, the economic benefit from 5% biomass co-firing is estimated to be $38.55 million assuming the medium emission reduction scenario, moderate carbon price ($16/ton of CO2) which is higher than the additional cost of biomass co-firing to generate electricity ($34.84 million). The benefit cost ratio is calculated as 1.107. Five percent biomass co-firing is economically feasible when benefits from all the positive externalities are included. The findings of the research suggest that in order to make 5% biomass co-firing physically and economically feasible, Utah needs cooperation from Idaho and the price of carbon and biomass would have to be $16 and $20, respectively.
10

Experimental Study on the Influence of Ammonia and Hydrogen addition on Soot Formation in Laminar Coflow Ethylene Diffusion Flames

Aydin, Faruk Yigit 08 1900 (has links)
Ammonia and hydrogen are two alternative fuels that can help decarbonization as they can be produced using renewable energy. Ammonia has transportation, handling, and storage advantages over hydrogen even though its combustion characteristics are worse. One intermediate strategy to use ammonia or hydrogen as a fuel is to co-fire it with hydrocarbons. However, co-firing with hydrocarbons may emit harmful pollutants such as NOx and soot. This study investigates the effects of ammonia and hydrogen addition on soot formation in laminar coflow nitrogen-diluted-ethylene normal diffusion flames using experimental techniques. Ammonia and hydrogen were added separately to the fuel flow. Flame conditions from 0 to 50 vol% of the added species (ammonia or hydrogen) were tested. Laser diagnostics for measuring the distributions of polycyclic aromatic hydrocarbons (PAHs) and soot volume fraction (SVF), and intrusive measurements (using a thermocouple and probe sampling) were performed. Based on the results, ammonia addition suppressed soot formation while hydrogen addition enhanced it. In conditions with ammonia addition, the temperature measurements with a Type S thermocouple and adiabatic flame temperature simulations using CHEMKIN PRO showed similar temperature profiles and negligible adiabatic flame temperature differences respectively. The qualitative PAH measurements using planar laser induced fluorescence (PLIF) showed that the concentration of PAHs of four or larger rings reduced with ammonia addition. Soot volume fraction (SVF) measurements using planar laser induced incandescence (PLII) showed that the peak SVF decreased exponentially with ammonia addition. Particle size distributions showed that the incipient particles were formed, however growth to mature primary particles was limited with 25% or higher ammonia addition in the flame. Based on similar temperature profiles and decreasing trends in the distribution of PAHs and SVF, soot suppression with ammonia addition was linked to chemical effects. PLIF measurements with hydrogen addition could be affected by the temperature difference between the flames, therefore further investigation is needed. PLII measurements, however, showed that the soot volume fraction increased linearly with hydrogen addition.

Page generated in 0.06 seconds