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Articles 331 - 360 of 3930

Full-Text Articles in Physical Sciences and Mathematics

Monte Carlo Simulation Of Thallium-Bromide Semiconductor Detector For Range Verification Of A Carbon Ion Radiotherapy Beam Through Prompt Gamma-Ray Detection, Peter Dimpfl Aug 2022

Monte Carlo Simulation Of Thallium-Bromide Semiconductor Detector For Range Verification Of A Carbon Ion Radiotherapy Beam Through Prompt Gamma-Ray Detection, Peter Dimpfl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thallium-Bromide is a semiconductor material which is well suited for photon detection. Composed of high atomic number elements and a high mass density of 7.56 g/cm3, TlBr has superb photon stopping power. External beam radiation therapy is an ever-changing environment with technology rapidly improving. With proton therapy facilities becoming more widely available, and carbon ion facilities showcasing the benefits of carbon ion radiation therapy, there is an industry need toprovide accurate dosimetric treatment plans to verify patients are receiving proper care. Current clinical practices apply safety margins to clinical target volumes to safe treatment. Through research to improve detection techniques, …

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Antler Foreland Basin Evolution Recorded In Detrital Zircon U-Pb Geochronology, James Duncan Aug 2022

Antler Foreland Basin Evolution Recorded In Detrital Zircon U-Pb Geochronology, James Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Antler orogeny was a Devonian-Mississippian (375-320 Ma) mountain building event that occurred along the western Laurentian margin. The initiation of the Antler orogeny is marked by the emplacement of the Roberts Mountain Allochthon (RMA) that thrust Cambrian-Devonian deep water marine siliciclastic rocks 100 km eastward onto the western Laurentian margin. Shortening related to the Antler orogeny deformed RMA strata and caused a flexural response in the continental crust that resulted in the formation of the adjacent Antler Foreland basin. The paleogeographic history of the RMA strata and tectonic drivers for the Antler orogeny are still debated. Proposed models suggest …

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Dissolution And Electrochemical Recovery Of Uo2, Uo3, And U3o8 In Ionic Liquids, Katherine Iolani Thornock Luebke Aug 2022

Dissolution And Electrochemical Recovery Of Uo2, Uo3, And U3o8 In Ionic Liquids, Katherine Iolani Thornock Luebke

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research explores a novel method of increasing the solubility of uranium oxides and other actinide oxides in room temperature ionic liquids (IL) using direct dissolution. The goal is to further expand our knowledge of actinide dissolution and possible nuclear fuel cycle material applications using ionic liquids. The novelty of the methods is focused on the use of oxidizing gas generated using air passed through an ozone generator. While examples of dissolution exist in IL using acidic functionalized ionic liquids, the solubility of all possible oxide species was not demonstrated. Also, the addition of aqueous acid to IL containing actinide …

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Hyperspectral Image Analysis Of Food For Nutritional Intake, Shirin Nasr Esfahani Aug 2022

Hyperspectral Image Analysis Of Food For Nutritional Intake, Shirin Nasr Esfahani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary object of this dissertation is to investigate the application of hyperspectral technology to accommodate for the growing demand in the automatic dietary assessment applications. Food intake is one of the main factors that contribute to human health. In other words, it is necessary to get information about the amount of nutrition and vitamins that a human body requires through a daily diet. Manual dietary assessments are time-consuming and are also not precise enough, especially when the information is used for the care and treatment of hospitalized patients. Moreover, the data must be analyzed by nutritional experts. Therefore, researchers …

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Source And Parental Melts Of Poikilitic Shergottites: Implications For Martian Magmatism, Evan W. O'Neal Aug 2022

Source And Parental Melts Of Poikilitic Shergottites: Implications For Martian Magmatism, Evan W. O'Neal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Martian poikilitic shergottite meteorites are cumulate rocks that can be used to understand melt evolution on Mars from the bottom of the crust (~10 kbar) all the way up to near-surface shallow depths (~1 kbar). There is a general lack of knowledge regarding shergottites including, parental magma compositions, crystallization ages, and the location of the enriched geochemical source of the shergottites in the martian mantle. Through a comprehensive petrographic and geochemical study, we have attempted to better understand poikilitic shergottite formation and the evolution of the martian interior during the Amazonian period (~3 Ga – present day). We studied a …

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The Application Of Detrital Zircon Geochronology, Pressure-Temperature Modeling, Monazite Petrochronology, And Quartz-In-Garnet Elastic Geobarometry To The Tectonic Evolution Of The Funeral Mountains And Related Metamorphic Core Complexes, Suzanne Renae Mulligan Aug 2022

The Application Of Detrital Zircon Geochronology, Pressure-Temperature Modeling, Monazite Petrochronology, And Quartz-In-Garnet Elastic Geobarometry To The Tectonic Evolution Of The Funeral Mountains And Related Metamorphic Core Complexes, Suzanne Renae Mulligan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigates and applies different techniques for studying mid-crustal metamorphic rocks including detrital zircon geochronology, monazite petrochronology, thermodynamic pressure-temperature modeling, and elastic geobarometry. The first chapter reconstructs stratigraphy in deformed metamorphic rocks from the Funeral Mountains metamorphic core complex in Death Valley, California, and the Bullfrog Hills, Nevada, using U-Pb detrital zircon (DZ) geochronology. This study documents another successful application of stratigraphic techniques applied to metamorphic rocks and migmatites. DZ geochronology identified Pahrump Group metasediments in rocks that were previously interpreted to be Paleoproterozoic basement gneisses, providing insights into the distribution of Rodinia rift basins. This analysis has shown …

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Reachability And Turn Constraint Paths, Sabrina Wallace Aug 2022

Reachability And Turn Constraint Paths, Sabrina Wallace

UNLV Theses, Dissertations, Professional Papers, and Capstones

Problems dealing with the development of efficient algorithms for constructing collision-free paths have been explored extensively. We review existing algorithms for constructing collision-free paths under turn-angle constraints. We examine the problem of computing collision-free paths in the presence of polygonal obstacles. We present an algorithm for identifying the placement of a source vertex so that the maximum number of obstacle vertices can be reached via the shortest path tree under turn-angle requirements. We also present some experimental results on the construction of collision-free paths in the presence of polygonal obstacles.

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The Disk Of Fu Orionis Viewed With Matisse/Vlti: First Interferometric Observations In L And M Bands, Foteini Lykou, P. Ábrahám, L. Chen, J. Varga, Á. Kóspál, A. Matter, M. Siwak, Zs. M. Szabo, Z. Zhu, H. B. Liu, B. Lopez, F. Allouche, J.-C. Augereau, P. Berio, P. Cruzalebes, C. Dominik, Th Henning, K.-H. Hofmann, M. Hogerheijde, W. J. Jaffe, E. Kokulina, S. Lagarde, A. Meilland, F. Millour, E. Pantin, R. Petrov, S. Robbe-Dubois, D. Schertl, M. Scheuck, R. Van Boekel, L. B. F. M. Waters, G. Weigelt, S. Wolf Jul 2022

The Disk Of Fu Orionis Viewed With Matisse/Vlti: First Interferometric Observations In L And M Bands, Foteini Lykou, P. Ábrahám, L. Chen, J. Varga, Á. Kóspál, A. Matter, M. Siwak, Zs. M. Szabo, Z. Zhu, H. B. Liu, B. Lopez, F. Allouche, J.-C. Augereau, P. Berio, P. Cruzalebes, C. Dominik, Th Henning, K.-H. Hofmann, M. Hogerheijde, W. J. Jaffe, E. Kokulina, S. Lagarde, A. Meilland, F. Millour, E. Pantin, R. Petrov, S. Robbe-Dubois, D. Schertl, M. Scheuck, R. Van Boekel, L. B. F. M. Waters, G. Weigelt, S. Wolf

Physics & Astronomy Faculty Research

Aims. We studied the accretion disk of the archetypal eruptive young star FU Orionis with the use of mid-infrared interferometry, which enabled us to resolve the innermost regions of the disk down to a spatial resolution of 3 milliarcseconds (mas) in the L band, that is, within 1 au of the protostar. Methods. We used the interferometric instrument MATISSE/VLTI to obtain observations of FU Ori’s disk in the L, M, and N bands with multiple baseline configurations. We also obtained contemporaneous photometry in the optical (UBVRIri ; SAAO and Konkoly Observatory) and near-infrared (JHKs; NOT). Our results were compared with …

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Wildfire Risk In Mountain West States, 2017-2021, Olivia K. Cheche, Corryn Richardson, Zachary Billot, Miguel Soriano Ralston, Vanessa Booth, Caitlin J. Saladino, William E. Brown Jr. Jul 2022

Wildfire Risk In Mountain West States, 2017-2021, Olivia K. Cheche, Corryn Richardson, Zachary Billot, Miguel Soriano Ralston, Vanessa Booth, Caitlin J. Saladino, William E. Brown Jr.

Environment

This fact sheet examines data on wildfire destruction in the Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah. The original report from the Insurance Information Institute presents findings on percent of properties at risk of wildfire destruction, the number of wildfires by state, and numbers of acres burned per state.

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Coexistence Of Vitreous And Crystalline Phases Of H2o At Ambient Temperature, Ali K. Shargh, Aude Picard, Rostislav Hrubiak, Dongzhou Zhang, Russell J. Hemley, Shanti Deemyad, Niaz Abdolrahim, Saveez Saffarian Jul 2022

Coexistence Of Vitreous And Crystalline Phases Of H2o At Ambient Temperature, Ali K. Shargh, Aude Picard, Rostislav Hrubiak, Dongzhou Zhang, Russell J. Hemley, Shanti Deemyad, Niaz Abdolrahim, Saveez Saffarian

Life Sciences Faculty Research

Formation of vitreous ice during rapid compression of water at room temperature is important for biology and the study of biological systems. Here, we show that Raman spectra of rapidly compressed water at greater than 1 GPa at room temperature exhibits the signature of high-density amorphous ice, whereas the X-ray diffraction (XRD) pattern is dominated by crystalline ice VI. To resolve this apparent contradiction, we used molecular dynamics simulations to calculate full vibrational spectra and diffraction patterns of mixtures of vitreous ice and ice VI, including embedded interfaces between the two phases. We show quantitatively that Raman spectra, which probe …

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Steel Module-To-Concrete Core Connection Methods In High Rise Modular Buildings: A Critical Review, Bishal Poudel, Seungtaek Lee, Jin Ouk Choi Jun 2022

Steel Module-To-Concrete Core Connection Methods In High Rise Modular Buildings: A Critical Review, Bishal Poudel, Seungtaek Lee, Jin Ouk Choi

Civil and Environmental Engineering and Construction Faculty Research

Modularization in a high-rise building is different from a small building, as it is exposed to more lateral forces like wind and earthquakes. The integrity, robustness, and overall stability of the modules and their performance is based on the joining techniques and strong structural systems. High lateral stiff construction structures like concrete shear walls and frames, braced steel frames, and steel moment frames are used for the stability of high-rise modular buildings. Similarly, high-rise stick-built buildings have concrete cores and perimeter frames for lateral load strength and stiffness. Methods for general steel-concrete connections are available in many works of literature. …

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A Repeating Fast Radio Burst Associated With A Persistent Radio Source, C.-H. Niu, K. Aggarwal, D. Li, X. Zhang, S. Chatterjee, C.-W. Tsai, W. Yu, C. J. Law, S. Burke-Spolaor, J. M. Cordes, Y.-K. Zhang, S. K. Ocker, J.-M. Yao, P. Wang, Y. Feng, Y. Niino, C. Bochenek, M. Cruces, L. Connor, J.-A. Jiang, S. Dai, R. Luo, G.-D. Li, C.-C. Miao, J.-R. Niu, R. Anna-Thomas, J. Sydnor, D. Stern, W.-Y. Wang, M Yuan, Y.-L. Yue, D.-J. Zhou, Z Yan, W.-W. Zhu, B. Zhang Jun 2022

A Repeating Fast Radio Burst Associated With A Persistent Radio Source, C.-H. Niu, K. Aggarwal, D. Li, X. Zhang, S. Chatterjee, C.-W. Tsai, W. Yu, C. J. Law, S. Burke-Spolaor, J. M. Cordes, Y.-K. Zhang, S. K. Ocker, J.-M. Yao, P. Wang, Y. Feng, Y. Niino, C. Bochenek, M. Cruces, L. Connor, J.-A. Jiang, S. Dai, R. Luo, G.-D. Li, C.-C. Miao, J.-R. Niu, R. Anna-Thomas, J. Sydnor, D. Stern, W.-Y. Wang, M Yuan, Y.-L. Yue, D.-J. Zhou, Z Yan, W.-W. Zhu, B. Zhang

Physics & Astronomy Faculty Research

The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift …

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Preliminary Planning For Mars Sample Return (Msr) Curation Activities In A Sample Receiving Facility (Srf), Kimberly T. Tait, Francis M. Mccubbin, Caroline L. Smith, Carl B. Agee, Henner Busemann, Barbara Cavalazzi, Viciane Debaille, Aurore Hutzler, Tomohiro Usui, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Charles S. Cockell, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Bernard Marty, Lisa M. Pratt, Aaron B. Regberg, Alvin L. Smith, Roger E. Summons, Timothy D. Swindle, Nicholas J, Tosca, Arya Urdry, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano Jun 2022

Preliminary Planning For Mars Sample Return (Msr) Curation Activities In A Sample Receiving Facility (Srf), Kimberly T. Tait, Francis M. Mccubbin, Caroline L. Smith, Carl B. Agee, Henner Busemann, Barbara Cavalazzi, Viciane Debaille, Aurore Hutzler, Tomohiro Usui, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Charles S. Cockell, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Bernard Marty, Lisa M. Pratt, Aaron B. Regberg, Alvin L. Smith, Roger E. Summons, Timothy D. Swindle, Nicholas J, Tosca, Arya Urdry, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano

Geoscience Faculty Research

The Mars Sample Return Planning Group 2 (MSPG2) was tasked with identifying the steps that encompass all the curation activities that would happen within the MSR Sample Receiving Facility (SRF) and any anticipated curation-related requirements. An area of specific interest is the necessary analytical instrumentation. The SRF would be a Biosafety Level-4 facility where the returned MSR flight hardware would be opened, the sample tubes accessed, and the martian sample material extracted from the tubes. Characterization of the essential attributes of each sample would be required to provide enough information to prepare a sample catalog used in guiding the preparation …

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Science And Curation Considerations For The Design Of A Mars Sample Return (Msr) Sample Receiving Facility (Srf), Brandi L. Carrier, David W. Beaty, Aurore Hutzler, Alvin L. Smith, Gerhard Kminek, Michael A. Meyer, Timothy Haltigin, Lindsey E. Hays, Carl B. Agee, Henner Busemann, Barabara Cavalazzi, Charles S. Cocksell, Vinciane Debaille, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Bernard Marty, Francis M., Lisa M. Pratt, Aaron B. Regberg, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Taiit, Nocholas J. Tosca, Arya Urdry, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano Jun 2022

Science And Curation Considerations For The Design Of A Mars Sample Return (Msr) Sample Receiving Facility (Srf), Brandi L. Carrier, David W. Beaty, Aurore Hutzler, Alvin L. Smith, Gerhard Kminek, Michael A. Meyer, Timothy Haltigin, Lindsey E. Hays, Carl B. Agee, Henner Busemann, Barabara Cavalazzi, Charles S. Cocksell, Vinciane Debaille, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Bernard Marty, Francis M., Lisa M. Pratt, Aaron B. Regberg, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Taiit, Nocholas J. Tosca, Arya Urdry, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano

Geoscience Faculty Research

The most important single element of the “ground system” portion of a Mars Sample Return (MSR) Campaign is a facility referred to as the Sample Receiving Facility (SRF), which would need to be designed and equipped to receive the returned spacecraft, extract and open the sealed sample container, extract the samples from the sample tubes, and implement a set of evaluations and analyses of the samples. One of the main findings of the first MSR Sample Planning Group (MSPG, 2019a) states that “The scientific community, for reasons of scientific quality, cost, and timeliness, strongly prefers that as many sample-related investigations …

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The Scientific Importance Of Returning Airfall Dust As A Part Of Mars Sample Return (Msr), Monica M. Grady, Roger E. Summons, Timothy D. Swindle, Frances Westall, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agee, Henner Busemann, Barabara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Daniel P. Galvin, Ernst Hauber, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Lisa M. Pratt, Aaron B, Regberg, Alvin L. Smith, Caroline L. Smith, Kimberly T. Tait, Nicholas J. Tosca, Arya Udry, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Maria-Paz Zorzano Jun 2022

The Scientific Importance Of Returning Airfall Dust As A Part Of Mars Sample Return (Msr), Monica M. Grady, Roger E. Summons, Timothy D. Swindle, Frances Westall, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agee, Henner Busemann, Barabara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Daniel P. Galvin, Ernst Hauber, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Lisa M. Pratt, Aaron B, Regberg, Alvin L. Smith, Caroline L. Smith, Kimberly T. Tait, Nicholas J. Tosca, Arya Udry, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Maria-Paz Zorzano

Geoscience Faculty Research

Dust transported in the martian atmosphere is of intrinsic scientific interest and has relevance for the planning of human missions in the future. The MSR Campaign, as currently designed, presents an important opportunity to return serendipitous, airfall dust. The tubes containing samples collected by the Perseverance rover would be placed in cache depots on the martian surface perhaps as early as 2023–24 for recovery by a subsequent mission no earlier than 2028–29, and possibly as late as 2030–31. Thus, the sample tube surfaces could passively collect dust for multiple years. This dust is deemed to be exceptionally valuable as it …

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Time-Sensitive Aspects Of Mars Sample Return (Msr) Science, Nicholas J. Tosca, Carl B. Agee, Charles S. Cockell, Daniel P. Glavin, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Aaron B. Regberg, Michael A. Velbel, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Henner Baumann, Barbara Cavalazzi, Vinviane Debaille, Monica M. Grady, Ernst Hauber, Lisa M. Pratt, Alvin L. Smith, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Arya Udry, Tomohiro Usui, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano Jun 2022

Time-Sensitive Aspects Of Mars Sample Return (Msr) Science, Nicholas J. Tosca, Carl B. Agee, Charles S. Cockell, Daniel P. Glavin, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Aaron B. Regberg, Michael A. Velbel, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Henner Baumann, Barbara Cavalazzi, Vinviane Debaille, Monica M. Grady, Ernst Hauber, Lisa M. Pratt, Alvin L. Smith, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Arya Udry, Tomohiro Usui, Meenakshi Wadhwa, Frances Westall, Maria-Paz Zorzano

Geoscience Faculty Research

Samples returned from Mars would be placed under quarantine at a Sample Receiving Facility (SRF) until they are considered safe to release to other laboratories for further study. The process of determining whether samples are safe for release, which may involve detailed analysis and/or sterilization, is expected to take several months. However, the process of breaking the sample tube seal and extracting the headspace gas will perturb local equilibrium conditions between gas and rock and set in motion irreversible processes that proceed as a function of time. Unless these time-sensitive processes are understood, planned for, and/or monitored during the quarantine …

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Planning Implications Related To Sterilization-Sensitive Science Investigations Associated With Mars Sample Return (Msr), Michael A. Velbel, Charles S. Cockell, Daniel P. Glavin, Bernard Marty, Aaron B. Regberg, Alvin L. Smith, Nicholas J. Tosca, Meenakshi Wadhwa, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi Lee Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agee, Henner Busemann, Barbara Cavalazzi, Vinciane Debaille, Monica M. Grady, Ernst Hauber, Aurore Hutzler, Francis M. Mccubbin, Lisa M. Pratt, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Arya Udry, Tomohiro Usui, Frances Westall, Maria-Paz Zorzano Jun 2022

Planning Implications Related To Sterilization-Sensitive Science Investigations Associated With Mars Sample Return (Msr), Michael A. Velbel, Charles S. Cockell, Daniel P. Glavin, Bernard Marty, Aaron B. Regberg, Alvin L. Smith, Nicholas J. Tosca, Meenakshi Wadhwa, Gerhard Kminek, Michael A. Meyer, David W. Beaty, Brandi Lee Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agee, Henner Busemann, Barbara Cavalazzi, Vinciane Debaille, Monica M. Grady, Ernst Hauber, Aurore Hutzler, Francis M. Mccubbin, Lisa M. Pratt, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Arya Udry, Tomohiro Usui, Frances Westall, Maria-Paz Zorzano

Geoscience Faculty Research

The NASA/ESA Mars Sample Return (MSR) Campaign seeks to establish whether life on Mars existed where and when environmental conditions allowed. Laboratory measurements on the returned samples are useful if what is measured is evidence of phenomena on Mars rather than of the effects of sterilization conditions. This report establishes that there are categories of measurements that can be fruitful despite sample sterilization and other categories that cannot. Sterilization kills living microorganisms and inactivates complex biological structures by breaking chemical bonds. Sterilization has similar effects on chemical bonds in non-biological compounds, including abiotic or pre-biotic reduced carbon compounds, hydrous minerals, …

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Final Report Of The Mars Sample Return Science Planning Group 2 (Mspg2), Michael A. Meyer, Gerhard Kminek, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agree, Henner Busemann, Barbara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Lisa M. Pratt, Aaron B. Regberg, Alvin L. Smith, Carolina L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Nicholas J. Tosca, Arya Udry, Tomohiro Usui, Michael A. Velbel, Meensakshi Wadhwa, Frances Westall, Maria-Paz Zorzano Jun 2022

Final Report Of The Mars Sample Return Science Planning Group 2 (Mspg2), Michael A. Meyer, Gerhard Kminek, David W. Beaty, Brandi L. Carrier, Timothy Haltigin, Lindsay E. Hays, Carl B. Agree, Henner Busemann, Barbara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Daniel P. Glavin, Monica M. Grady, Ernst Hauber, Aurore Hutzler, Bernard Marty, Francis M. Mccubbin, Lisa M. Pratt, Aaron B. Regberg, Alvin L. Smith, Carolina L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Nicholas J. Tosca, Arya Udry, Tomohiro Usui, Michael A. Velbel, Meensakshi Wadhwa, Frances Westall, Maria-Paz Zorzano

Geoscience Faculty Research

The Mars Sample Return (MSR) Campaign must meet a series of scientific and technical achievements to be successful. While the respective engineering responsibilities to retrieve the samples have been formalized through a Memorandum of Understanding between ESA and NASA, the roles and responsibilities of the scientific elements have yet to be fully defined. In April 2020, ESA and NASA jointly chartered the MSR Science Planning Group 2 (MSPG2) to build upon previous planning efforts in defining 1) an end-to-end MSR Science Program and 2) needed functionalities and design requirements for an MSR Sample Receiving Facility (SRF). The challenges for the …

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Rationale And Proposed Design For A Mars Sample Return (Msr) Science Program, Timothy Haltigin, Ernst Hauber, Gerhard Kminek, Michael A. Meyer, Carl B. Agee, Henner Busemann, Brandi L. Carrier, Daniel P. Glavin, Lindsay E. Hays, Bernard Marty, Lisa M. Pratt, Arya Udry, Maria-Paz Zorzano, David W. Beaty, Barbara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Monica M. Grady, Aurore Hutzler, Francis M. Mccubbin, Aaron B. Regberg, Alvin L. Smith, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Nicholas J. Tosca, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall Jun 2022

Rationale And Proposed Design For A Mars Sample Return (Msr) Science Program, Timothy Haltigin, Ernst Hauber, Gerhard Kminek, Michael A. Meyer, Carl B. Agee, Henner Busemann, Brandi L. Carrier, Daniel P. Glavin, Lindsay E. Hays, Bernard Marty, Lisa M. Pratt, Arya Udry, Maria-Paz Zorzano, David W. Beaty, Barbara Cavalazzi, Charles S. Cockell, Vinciane Debaille, Monica M. Grady, Aurore Hutzler, Francis M. Mccubbin, Aaron B. Regberg, Alvin L. Smith, Caroline L. Smith, Roger E. Summons, Timothy D. Swindle, Kimberly T. Tait, Nicholas J. Tosca, Tomohiro Usui, Michael A. Velbel, Meenakshi Wadhwa, Frances Westall

Geoscience Faculty Research

The Mars Sample Return (MSR) Campaign represents one of the most ambitious scientific endeavors ever undertaken. Analyses of the martian samples would offer unique science benefits that cannot be attained through orbital or landed missions that rely only on remote sensing and in situ measurements, respectively. As currently designed, the MSR Campaign comprises a number of scientific, technical, and programmatic bodies and relationships, captured in a series of existing and anticipated documents. Ensuring that all required scientific activities are properly designed, managed, and executed would require significant planning and coordination. Because there are multiple scientific elements that would need to …

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A Generalized Family Of Exponentiated Composite Distributions, Bowen Liu, Malwane Ananda Jun 2022

A Generalized Family Of Exponentiated Composite Distributions, Bowen Liu, Malwane Ananda

Mathematical Sciences Faculty Research

In this paper, we propose a new family of distributions, by exponentiating the random variables associated with the probability density functions of composite distributions. We also derive some mathematical properties of this new family of distributions, including the moments and the limited moments. Specifically, two special models in this family are discussed. Three real datasets were chosen, to assess the performance of these two special exponentiated-composite models. When fitting to these three datasets, these three special exponentiated-composite distributions demonstrate significantly better performance, compared to the original composite distributions.

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Climatic Backdrop For Pueblo Cultural Development In The Southwestern United States, Victor J. Polyak, Yemane Asmerom, Matthew S. Lachniet May 2022

Climatic Backdrop For Pueblo Cultural Development In The Southwestern United States, Victor J. Polyak, Yemane Asmerom, Matthew S. Lachniet

Geoscience Faculty Research

While climatic triggers for collapse and population migrations of ancestral Pueblo communities have been proposed, little is known about the overall climatic backdrop for the entire pre-Hispanic Pueblo period (ca. 1300 to 460 B2K). Here, we report data from stalagmite HC-1, from Hidden Cave, Guadalupe Mountains, New Mexico, covering the past 3400 years, showing an interval of increased frequency of droughts from 1260 to 370 yr B2K that is coeval with the entire pre-Hispanic Pueblo period. Our record suggests that this puebloan Late Holocene climatic interval was the most arid and highly variable climatic period of the last 3400 years. …

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Evaluating The Behaviour Of Centrally Perforated Unreinforced Masonry Walls: Applications Of Numerical Analysis, Machine Learning, And Stochastic Methods, Mohsen Khaleghi, Javid Salimi, Visar Farhangi, Mohammad Javad Moradi, Moses Karakouzian May 2022

Evaluating The Behaviour Of Centrally Perforated Unreinforced Masonry Walls: Applications Of Numerical Analysis, Machine Learning, And Stochastic Methods, Mohsen Khaleghi, Javid Salimi, Visar Farhangi, Mohammad Javad Moradi, Moses Karakouzian

Civil and Environmental Engineering and Construction Faculty Research

The presence of openings greatly affects the response of unreinforced masonry (URM) walls. This topic greatly attracts the attention of many researchers. Perforated unreinforced masonry (PURM) walls under in-plane loads through the truss discretization method (TDM) along with several machine learning approaches such as Multilayer perceptron (MLP), Group of Method Data Handling (GMDH), and Radial basis function (RBF) are described in this paper. A new method named Multi-pier (MP) that is fast and accurate, is used to determine the behavior of PURM walls. The results of the MP method are expressed as a ratio of lateral load-bearing capacity and initial …

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Dust-Gas Dynamics Driven By The Streaming Instability With Various Pressure Gradients, Stanley Antedio Baronett May 2022

Dust-Gas Dynamics Driven By The Streaming Instability With Various Pressure Gradients, Stanley Antedio Baronett

UNLV Theses, Dissertations, Professional Papers, and Capstones

The radial pressure gradient (RPG), along the midplane of gaseous protoplanetary disks (PPD) – planetary nurseries – poses a severe obstacle to planet formation. Micron-sized dust grains, embedded in the disc, must quickly grow to kilometer-sized planetesimals – the building blocks of planets – before fatally drifting inwards, by RPG-induced gas drag, into a central host star. However, the RPG simultaneously powers one of the most robust processes to overcome this radial-drift barrier: the streaming instability (SI). Spontaneously triggered, the SI aerodynamically concentrates drifting dust via drag-induced, coupled interactions and feedback with the surrounding gas. In particular, the non-linear phase …

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Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara May 2022

Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the pioneering achievements in condensed matter physics of the 20th century is the observation of the quantum Hall e↵ect (QHE) in which the Hall resistance in a two-dimensional (2D) sample takes on quantized values in the presence of a strong perpendicular magnetic field. The precise quantization of the hall resistance to one part in a billion has provided a practical, worldwide resistance standard. A long-standing goal has been to realize a similar state of matter but without the need of a strong quantizing magnetic field. The quantum anomalous Hall e↵ect (QAHE) is such a state that is predicted …

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Positive Solutions To Semilinear Elliptic Equations With Logistic-Type Nonlinearities And Harvesting In Exterior Domains, Eric Jameson May 2022

Positive Solutions To Semilinear Elliptic Equations With Logistic-Type Nonlinearities And Harvesting In Exterior Domains, Eric Jameson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Existing results provide the existence of positive solutions to a class of semilinear elliptic PDEs with logistic-type nonlinearities and harvesting terms both in RN and in bounded domains U ⊂ RN with N ≥ 3, when the carrying capacity of the environment is not constant. We consider these same equations in the exterior domain Ω, defined as the complement of the closed unit ball in RN , N ≥ 3, now with a Dirichlet boundary condition. We first show that the existing techniques forsolving these equations in the whole space RN can be applied to the exterior domain with some …

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Physics Of Electromagnetic Counterparts Of Binary-Neutron-Star Mergers, Shunke Ai May 2022

Physics Of Electromagnetic Counterparts Of Binary-Neutron-Star Mergers, Shunke Ai

UNLV Theses, Dissertations, Professional Papers, and Capstones

Binary neutron star (BNS) mergers are supposed to be the sources of a variety of astrophysical transients, including both gravitational wave (GW) and electromagnetic (EM) signals. The types and properties of the post-merger central product contain crucial information for many unsolved physical problems. Since the current GW detectors are not sensitive enough in kHz, only GWs from the inspiral phase can be detected, so that one cannot directly study the central products from GWs. EM signals can serve as probes to infer the type and properties of the central product. When a long-lived neutron star (NS) is formed after the …

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Radiomic Features To Predict Overall Survival Time For Patients With Glioblastoma Brain Tumors Based On Machine Learning And Deep Learning Methods, Lina Chato May 2022

Radiomic Features To Predict Overall Survival Time For Patients With Glioblastoma Brain Tumors Based On Machine Learning And Deep Learning Methods, Lina Chato

UNLV Theses, Dissertations, Professional Papers, and Capstones

Machine Learning (ML) methods including Deep Learning (DL) Methods have been employed in the medical field to improve diagnosis process and patient’s prognosis outcomes. Glioblastoma multiforme is an extremely aggressive Glioma brain tumor that has a poor survival rate. Understanding the behavior of the Glioblastoma brain tumor is still uncertain and some factors are still unrecognized. In fact, the tumor behavior is important to decide a proper treatment plan and to improve a patient’s health. The aim of this dissertation is to develop a Computer-Aided-Diagnosis system (CADiag) based on ML/DL methods to automatically estimate the Overall Survival Time (OST) for …

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Terrestrial Planet Formation In M-Dwarf And Binary Star Systems, Anna C. Childs May 2022

Terrestrial Planet Formation In M-Dwarf And Binary Star Systems, Anna C. Childs

UNLV Theses, Dissertations, Professional Papers, and Capstones

I examine circumbinary terrestrial planet formation in a gas free environment around various binary systems and terrestrial planet formation in a gaseous environment around M-dwarfs. While terrestrial cirumbinary planets have yet to be observed, this is likely due to observational bias. Motivated by recent observations of highly misaligned circumbinary gas disks, I perform a suite of n-body studies to understand the properties of terrestrial planets around various binary systems. In a polar alignment, a circumbinary disk is inclined by 90 degrees relative to the binary orbital plane. I find that terrestrial planet formation in a polar configuration may be as …

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Built Environment, Land Use, And Crime: A Las Vegas Study, Stacey Lynn Clouse May 2022

Built Environment, Land Use, And Crime: A Las Vegas Study, Stacey Lynn Clouse

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examined land use and crime against persons and crime against property in Las Vegas, Nevada at varying spatial levels of analysis. Using crime data provided by the Las Vegas Metropolitan Police Department and the Clark County Assessor’s office, results at the macro-level of analysis reveal that property crime rates concentrated on commercial, transportation, communication and utilities, and industrial land use, whereas violent crime concentrated at commercial, multi-residential, and civic, institutional, and recreational land use. Upon examining the subtypes of land use that generate or radiate more crime, property crime concentrated on transportation land use, class 1 resorts, and …

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The Effects Of Winds On Accretion Disks And Spectra Of X-Ray Binaries And Active Galactic Nuclei, Shalini Ganguly May 2022

The Effects Of Winds On Accretion Disks And Spectra Of X-Ray Binaries And Active Galactic Nuclei, Shalini Ganguly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Active galactic nuclei (AGNs) and X-ray binaries (XRBs) contain at their cores supermassive black holes (SMBH), and stellar mass black holes or neutron stars, respectively. These objects bind matter gravitationally, leading to the formation of accretion disks. The accretion of matter leads to efficient conversion of gravitational potential energy into radiation. When the force and/or energy imparted by this radiation on matter exceeds the attractive force due to the local gravitational field, it leads to the launching of matter in the form of outflows or winds. These outflows produce blueshifted (and occasionally redshifted) emission or absorption components in the spectra …

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