The effective application of international safeguards to research reactors requires verification of spent fuel as well as fresh fuel. To accomplish this goal various nondestructive and destructive assay techniques have been developed in the US and around the world. The Advanced Experimental Fuel Counter (AEFC) is a nondestructive assay (NDA) system developed at Los Alamos National Laboratory (LANL) combining both neutron and gamma measurement capabilities. Since spent fuel assemblies are stored in water, the system was designed to be watertight to facilitate underwater measurements by inspectors. The AEFC is comprised of six He detectors as well as a shielded and collimated ion chamber. The He detectors are used for active and passive neutron coincidence counting while the ion chamber is used for gross gamma counting. In the past, most of the active interrogation systems along with the AEFC were calibrated by AmLi neutron source. In this study, experiments were performed to calibrate the AEFC instrument and compare use of the Cf spontaneous fission source and the AmLi (α,n) neutron emission source. MCNP simulations were carried out to benchmark experiments. This thesis analyzes time correlated induced fission (TCIF) from fresh MTR fuel assemblies due to Cf and AmLi active interrogation sources. Benchmarking showed MCNP singles and doubles count rates agree with experimental singles and doubles within 5% and 4% respectively in the case of full assembly. After normalizing Cf to the AmLi source strength, AmLi resulted 1.228 times more IF singles rate, while Cf resulted 1.176 times more IF doubles rate. This indicates the boost in the doubles rate with Cf source is due to the TCIF effect.
{"title":"Comparison Of 252Cf Time Correlated Induced Fisssion With AmLi Induced Fission On Fresh MTR Research Reactor Fuel","authors":"J. Joshi","doi":"10.2172/1351252","DOIUrl":"https://doi.org/10.2172/1351252","url":null,"abstract":"The effective application of international safeguards to research reactors requires verification of spent fuel as well as fresh fuel. To accomplish this goal various nondestructive and destructive assay techniques have been developed in the US and around the world. The Advanced Experimental Fuel Counter (AEFC) is a nondestructive assay (NDA) system developed at Los Alamos National Laboratory (LANL) combining both neutron and gamma measurement capabilities. Since spent fuel assemblies are stored in water, the system was designed to be watertight to facilitate underwater measurements by inspectors. The AEFC is comprised of six He detectors as well as a shielded and collimated ion chamber. The He detectors are used for active and passive neutron coincidence counting while the ion chamber is used for gross gamma counting. In the past, most of the active interrogation systems along with the AEFC were calibrated by AmLi neutron source. In this study, experiments were performed to calibrate the AEFC instrument and compare use of the Cf spontaneous fission source and the AmLi (α,n) neutron emission source. MCNP simulations were carried out to benchmark experiments. This thesis analyzes time correlated induced fission (TCIF) from fresh MTR fuel assemblies due to Cf and AmLi active interrogation sources. Benchmarking showed MCNP singles and doubles count rates agree with experimental singles and doubles within 5% and 4% respectively in the case of full assembly. After normalizing Cf to the AmLi source strength, AmLi resulted 1.228 times more IF singles rate, while Cf resulted 1.176 times more IF doubles rate. This indicates the boost in the doubles rate with Cf source is due to the TCIF effect.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"55 1","pages":"24"},"PeriodicalIF":0.0,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80448631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce high-quality and large-quantities of nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and sizefocusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (< 7% relative standard deviation for Cu2-xS, CdS, and PbS), and demonstrate 10-1000 fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and lab-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot-injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a ten-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nano-manufacturing of NPs by relaxing synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties, and growth rates reveals that this high concentration regime has an order of magnitude increase in solution viscosity, reducing mass diffusion, a ~67% increase in heat capacity, stabilizing the reaction to perturbations, and the decreasing influence of Ostwald ripening.
{"title":"The Effects of Concentration Intensification on Nanoparticle Synthesis","authors":"C. Williamson","doi":"10.7298/X4F18WQV","DOIUrl":"https://doi.org/10.7298/X4F18WQV","url":null,"abstract":"Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce high-quality and large-quantities of nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and sizefocusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (< 7% relative standard deviation for Cu2-xS, CdS, and PbS), and demonstrate 10-1000 fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and lab-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot-injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a ten-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nano-manufacturing of NPs by relaxing synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties, and growth rates reveals that this high concentration regime has an order of magnitude increase in solution viscosity, reducing mass diffusion, a ~67% increase in heat capacity, stabilizing the reaction to perturbations, and the decreasing influence of Ostwald ripening.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"30 1","pages":"28"},"PeriodicalIF":0.0,"publicationDate":"2017-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78847648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Title of document: INVESTIGATION OF NOVEL MEMBRANE TECHNOLOGIES FOR HYDROGEN SEPARATION William M. Van Cleave, Master of Science, 2017 Thesis directed by: Professor Ashwani K. Gupta Department of Mechanical Engineering The production of hydrogen gas via its separation from multicomponent syngas derived from biomass is an important process in the burgeoning carbon-neutral hydrogen economy. Current methods utilize membranes made from expensive materials such as palladium or bulky pressure vessels that use adsorption properties. Holey graphene and doped perovskite ceramics are alternative membrane materials that are relatively inexpensive and easily produced. A range of holey graphene membranes was produced using dry pressing and other techniques, including high temperature reduction, to examine the efficiency of this material. Experimental results using these holey graphene membranes are presented from a lab-scale facility designed to test various membrane types. These results showed decreasing flux and increasing selectivity as membrane thickness increased. Comparison with results from literature indicate these membranes exhibit higher overall flux but lower selectivity when compared to palladium-based membrane technologies. INVESTIGATION OF NOVEL MEMBRANE TECHNOLOGIES FOR HYDROGEN SEPARATION
William M. Van Cleave，科学硕士，2017论文指导:Ashwani K. Gupta教授机械工程系通过分离来自生物质的多组分合成气来生产氢气是新兴的碳中性氢经济中的一个重要过程。目前的方法使用昂贵材料制成的膜，如钯或使用吸附特性的笨重压力容器。多孔石墨烯和掺杂钙钛矿陶瓷是相对便宜且易于生产的替代膜材料。使用干压和其他技术(包括高温还原)生产了一系列有孔的石墨烯膜，以检验这种材料的效率。使用这些多孔石墨烯膜的实验结果来自实验室规模的设备，旨在测试各种膜类型。结果表明，随着膜厚度的增加，通量降低，选择性增加。与文献结果的比较表明，与钯基膜技术相比，这些膜具有更高的总通量，但选择性较低。新型膜分离氢技术的研究
{"title":"Investigation of Novel Membrane Technologies for Hydrogen Separation","authors":"W. V. Cleave","doi":"10.13016/M29G5GD9P","DOIUrl":"https://doi.org/10.13016/M29G5GD9P","url":null,"abstract":"Title of document: INVESTIGATION OF NOVEL MEMBRANE TECHNOLOGIES FOR HYDROGEN SEPARATION William M. Van Cleave, Master of Science, 2017 Thesis directed by: Professor Ashwani K. Gupta Department of Mechanical Engineering The production of hydrogen gas via its separation from multicomponent syngas derived from biomass is an important process in the burgeoning carbon-neutral hydrogen economy. Current methods utilize membranes made from expensive materials such as palladium or bulky pressure vessels that use adsorption properties. Holey graphene and doped perovskite ceramics are alternative membrane materials that are relatively inexpensive and easily produced. A range of holey graphene membranes was produced using dry pressing and other techniques, including high temperature reduction, to examine the efficiency of this material. Experimental results using these holey graphene membranes are presented from a lab-scale facility designed to test various membrane types. These results showed decreasing flux and increasing selectivity as membrane thickness increased. Comparison with results from literature indicate these membranes exhibit higher overall flux but lower selectivity when compared to palladium-based membrane technologies. INVESTIGATION OF NOVEL MEMBRANE TECHNOLOGIES FOR HYDROGEN SEPARATION","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"53 76 1","pages":"12"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78605760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.31274/ETD-180810-4966
D. Kis
ix CHAPTER
第九章
{"title":"A Coupling Analysis Approach to Capture Unexpected Behaviors in Ares 1","authors":"D. Kis","doi":"10.31274/ETD-180810-4966","DOIUrl":"https://doi.org/10.31274/ETD-180810-4966","url":null,"abstract":"ix CHAPTER","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"66 1","pages":"19"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75928069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Wave Chaotic Study of Quantum Graphs with Microwave Networks","authors":"Ziyuan Fu","doi":"10.13016/M2Z60C28Q","DOIUrl":"https://doi.org/10.13016/M2Z60C28Q","url":null,"abstract":"","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"92 1","pages":"18"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78366349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Impact of Shale Gas on Gas Storage Performance
页岩气对储气性能的影响
{"title":"The Impact of Shale Gas on Gas Storage Performance","authors":"A. Sattari","doi":"10.33915/etd.6571","DOIUrl":"https://doi.org/10.33915/etd.6571","url":null,"abstract":"The Impact of Shale Gas on Gas Storage Performance","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"212 1","pages":"20"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73572619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"COMPARATIVE ANALYSIS OF MINIATURE INTERNAL COMBUSTION ENGINE AND ELECTRIC MOTOR FOR UAV PROPULSION","authors":"Branden Chiclana","doi":"10.13016/M2CF9J81N","DOIUrl":"https://doi.org/10.13016/M2CF9J81N","url":null,"abstract":"","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"42 1","pages":"58"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79914421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
..........................................................................................i ACKNOWLEDGEMENTS.........................................................................iv LIST OF TABLES.................................................................................viii LIST OF FIGURES..................................................................................ix CHAPTER
{"title":"The Social Acceptance of Community Solar: A Portland Case Study","authors":"A. Weaver","doi":"10.15760/ETD.3488","DOIUrl":"https://doi.org/10.15760/ETD.3488","url":null,"abstract":"..........................................................................................i ACKNOWLEDGEMENTS.........................................................................iv LIST OF TABLES.................................................................................viii LIST OF FIGURES..................................................................................ix CHAPTER","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"40 1","pages":"16"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79056651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As the performance of computers has improved dramatically since the 1990s, many interesting photonic crystal properties have been theoretically and experimentally discovered. For example, the strong coupling between photonic crystal cavities was revealed in the 2000s; many groups have successfully fabricated these cavities and verified strong coupling experimentally using silicon. In this thesis, instead of using silicon, we present new results on photonic crystals made by thin indium tin oxide (ITO) layers. Compared to silicon, ITO is not an ideal material to make a photonic crystal because of its comparatively low refractive index and limited transparency. However, it is an interesting model material for experiments in photoemission electron microscopy (PEEM). ITO has a high conductivity that mitigates surface charge-up in an electron microscope and allows electron emission after 2-photon absorption with visible light. We are interested in PEEM because it enables the visualization of the propagation of light with nanometer resolution, i.e., below the optical diffraction limit. In this thesis, we theoretically study ITO photonic crystals in one or two-dimensions with the help of the finite-difference time-domain (FDTD) software. We analyze the electromagnetic field distribution in a manner that the field distributions can directly be compared to experimental PEEM results. We also simulate the strong coupling effect between neighboring cavities and illustrate it in terms of the classical oscillator model.
{"title":"Strong Coupling Between Photonic Cavities","authors":"Xiang Wei","doi":"10.15760/ETD.6040","DOIUrl":"https://doi.org/10.15760/ETD.6040","url":null,"abstract":"As the performance of computers has improved dramatically since the 1990s, many interesting photonic crystal properties have been theoretically and experimentally discovered. For example, the strong coupling between photonic crystal cavities was revealed in the 2000s; many groups have successfully fabricated these cavities and verified strong coupling experimentally using silicon. In this thesis, instead of using silicon, we present new results on photonic crystals made by thin indium tin oxide (ITO) layers. Compared to silicon, ITO is not an ideal material to make a photonic crystal because of its comparatively low refractive index and limited transparency. However, it is an interesting model material for experiments in photoemission electron microscopy (PEEM). ITO has a high conductivity that mitigates surface charge-up in an electron microscope and allows electron emission after 2-photon absorption with visible light. We are interested in PEEM because it enables the visualization of the propagation of light with nanometer resolution, i.e., below the optical diffraction limit. In this thesis, we theoretically study ITO photonic crystals in one or two-dimensions with the help of the finite-difference time-domain (FDTD) software. We analyze the electromagnetic field distribution in a manner that the field distributions can directly be compared to experimental PEEM results. We also simulate the strong coupling effect between neighboring cavities and illustrate it in terms of the classical oscillator model.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"262 1","pages":"31"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73556985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fenestration systems are widely used across the world. There is expansive research on window configurations, frames, and glazing technology, but not enough research has been published on reducing window heat loss through heat application to a pane. The presented study attempted to evaluate the performance of heated windows by developing an experimental setup to test a window at various temperatures by varying the power input to the window. Heated double pane window was installed in an insulated box. A temperature gradient was developed across the window by cooling one side of the window using gel-based ice packs. The other face of the window was heated by enabling power at different wattages through the window. The temperature of the inside and outside panes, current and voltage input, and temperature of the room and box were recorded. The data was used to calculate the apparent effective resistance of the window when not being heated vs . when being heated. The study concluded that, when window temperature was maintained close to the room temperature, the heated double pane window is effective in reducing heat loss by as much as 50% as compared to a non-heated double pane window. When temperature of the window was much higher than the room temperature, the heat loss through the window increased beyond that of a non-heated window. The issues encountered during the current stages of experiments are noted, and recommendations are provided for future studies.
{"title":"Evaluation of Energy Efficiency Performance of Heated Windows","authors":"H. Jammulamadaka","doi":"10.33915/etd.5879","DOIUrl":"https://doi.org/10.33915/etd.5879","url":null,"abstract":"Fenestration systems are widely used across the world. There is expansive research on window configurations, frames, and glazing technology, but not enough research has been published on reducing window heat loss through heat application to a pane. The presented study attempted to evaluate the performance of heated windows by developing an experimental setup to test a window at various temperatures by varying the power input to the window. Heated double pane window was installed in an insulated box. A temperature gradient was developed across the window by cooling one side of the window using gel-based ice packs. The other face of the window was heated by enabling power at different wattages through the window. The temperature of the inside and outside panes, current and voltage input, and temperature of the room and box were recorded. The data was used to calculate the apparent effective resistance of the window when not being heated vs . when being heated. The study concluded that, when window temperature was maintained close to the room temperature, the heated double pane window is effective in reducing heat loss by as much as 50% as compared to a non-heated double pane window. When temperature of the window was much higher than the room temperature, the heat loss through the window increased beyond that of a non-heated window. The issues encountered during the current stages of experiments are noted, and recommendations are provided for future studies.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"6 1","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86468436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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