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2020

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Full-Text Articles in Engineering

Application Of Far And Near Trace Attributes For Avo Analysis In Deep Water Area In Qiongdongnan Basin, Liu Shiyou, Zhang Yingzhao, Li Yangsen, Yan Anju, Zhang Haiyang Feb 2020

Application Of Far And Near Trace Attributes For Avo Analysis In Deep Water Area In Qiongdongnan Basin, Liu Shiyou, Zhang Yingzhao, Li Yangsen, Yan Anju, Zhang Haiyang

Coal Geology & Exploration

For prestack seismic data with low signal-to-noise ratio(SNR), the effect of traditional AVO rendezvous analysis and intercept gradient product attribute(P×G attribute) may not be ideal. In order to extract the information of AVO attribute effectively, this paper starts from the prestack partial superposition body, according to the relative relation of the far and near track part superposition body, the far and near attribute factor similar to the P×G attribute was constructed, in which the near track stack reflects the intercept attribute, and the near-far stack difference reflects the intercept attribute, which is similar to the …


Application Of Small Scale Curvature In Small And Micro-Structure Interpretation Of Coal Field, Cheng Yan Feb 2020

Application Of Small Scale Curvature In Small And Micro-Structure Interpretation Of Coal Field, Cheng Yan

Coal Geology & Exploration

The interpretation and delineation of small and micro-structure which acts as one of the main disaster sources in coal mine is an important guarantee for safe and efficient production of coal mines. However, it can't satisfy the geological guarantee for precise mining by only using the traditional seismic exploration methods to solve this problem. Therefore, in this paper, we reconstruct the seismic data by extracting the components above 60 Hz from the 3D seismic data, and then extract minimum negative curvature to interpret and analyze the small and micro-structures in study areas. By comparing the revealed micro-structures and explained results …


Application Of Mine-Hole Joint Microseismic Technology In Monitoring The Damage Depth Of Working Face Floor, Duan Jianhua, Yan Wenchao, Nan Hanchen, Zhang Qingqing, Fan Xin Feb 2020

Application Of Mine-Hole Joint Microseismic Technology In Monitoring The Damage Depth Of Working Face Floor, Duan Jianhua, Yan Wenchao, Nan Hanchen, Zhang Qingqing, Fan Xin

Coal Geology & Exploration

Accurate prediction of the mining damage depth of floor is a key problem in the prevention and control of mining floor water hazard especially in the case with confined water. It is very important for developing the strategy of water control. According to the geological characteristics and working face layout of Baode coal mine, Shaanxi Province, a high-precision microseismic monitoring system consisting of well and hole arrays was deployed to detect the floor damage depth in working face 81307 in real time. The velocity model was calibrated and the location accuracy was verified by hammering method. It is proved that …


Forward Response Analysis Of Shield Advanced Detection With Moving Array Electrode, Zhao Shuanfeng, Bai Yunrui, Huang Tao, Wei Mingle Feb 2020

Forward Response Analysis Of Shield Advanced Detection With Moving Array Electrode, Zhao Shuanfeng, Bai Yunrui, Huang Tao, Wei Mingle

Coal Geology & Exploration

Aiming at problems of serious electromagnetic interference, difficult application in TBM(Tunnel Boring Machine) tunnel construction and so on, a method of shield advanced detection based on moving array electrodes is adopted. Using Comsol Multiphysics finite element simulation software to establish geoelectric model, forward response analysis is carried out for various geological conditions. The results show that adding the protective electrodes can obviously enlarge the voltage distribution range, which means the detection range increases. In order to improve the detection effect, it is necessary to add protective electrodes. Changes in the size, shape and position of the anomalous body will exhibit …


Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng Feb 2020

Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng

Coal Geology & Exploration

In order to study the physical mechanism of frequency dispersion of complex resistivity of coal at 0-200 kHz, the amplitude-frequency and phase-frequency of complex resistivity of coal are measured under variable frequency of constant current. Using the Fourier inverse transform to convert the frequency domain data of complex resistivity of coal into time domain data; Using the Cole-Cole model, the complex resistivity dispersion data are fitted; Drawing on the electric double layer deformation hypothesis theory, the dispersion mechanism of complex resistivity of coal is studied by comparing the frequency dispersion of sandstone. The results show that in the current frequency …


The Key Technology For Drilling Horizontal Well In Coal Seam Roof In Qianbei Mining Area, Hu Xinpeng, Zhao Yongzhe, Xu Kanshe, Wang Linjie, Li Peng, Duan Huijun Feb 2020

The Key Technology For Drilling Horizontal Well In Coal Seam Roof In Qianbei Mining Area, Hu Xinpeng, Zhao Yongzhe, Xu Kanshe, Wang Linjie, Li Peng, Duan Huijun

Coal Geology & Exploration

primary ways to develop the soft coal seam CBM. Aiming at the complex geological conditions and reservoir conditions in Qianbei mining area of Guizhou Province, in order to solve the problems of horizontal well leakage, well trajectory control and solid completion in the horizontal well drilling of coal seam roof, the key technology of horizontal well drilling of coal seam roof in Qianbei mining area, with the accurate control of trajectory as the core, and the technology of preventing leakage, eccentricity and solid completion are combined. Combined with on-site drilling practice, the problems of difficulties in horizontal well drilling were …


Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo Feb 2020

Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo

Coal Geology & Exploration

In order to explore the performance of PDC cutters at different temperatures to adapt to different brazing temperatures, and to reasonably select the shape to improve efficiency. Based on the several main parameters affecting the quality of polycrystalline diamond compacts (PDC), such as wear resistance, grinding time, stationarity and impact toughness, the performance of PDC sheets from different manufacturers and different shapes was tested. The performance of PDC before or after heating and at different temperatures was obtained. At the same time, the performance of flat sheets, micro-arcs sheets and arcs sheets was compared. The results show that with the …


Thoroughbred Racehorse Welfare Through The Lens Of ‘Social License To Operate—With An Emphasis On A U.S. Perspective, Camie Heleski, C. Jill Stowe, Julie Fiedler, Michael L. Peterson, Colleen Brady, Carissa Wickens, James N. Macleod Feb 2020

Thoroughbred Racehorse Welfare Through The Lens Of ‘Social License To Operate—With An Emphasis On A U.S. Perspective, Camie Heleski, C. Jill Stowe, Julie Fiedler, Michael L. Peterson, Colleen Brady, Carissa Wickens, James N. Macleod

Agricultural Economics Faculty Publications

This review addresses the question of whether Thoroughbred horse racing is sustainable in the context of current social values. A recently acknowledged framework, known as ‘Social License to Operate’ (SLO), provides us with a lens through which to view and assess racehorse welfare. In multiple surveys of the general public, the horse owning public, and university students, the primary topics of concern regarding Thoroughbred racing show considerable concordance: concern about catastrophic injuries—particularly as related to track surfaces, concern over the racing of two-year-olds, whip use by jockeys, drug/medication policies, and aftercare opportunities for retired Thoroughbred racehorses. Legitimacy of an industry, …


Numerical Simulation Of Rupture Process Of Shale Under Action Of Fluid-Solid Coupling, Lou Yili, Wu Zhonghu, Wang Anli, Zuo Yujun, Liu Hao, Sun Wenjibin Feb 2020

Numerical Simulation Of Rupture Process Of Shale Under Action Of Fluid-Solid Coupling, Lou Yili, Wu Zhonghu, Wang Anli, Zuo Yujun, Liu Hao, Sun Wenjibin

Coal Geology & Exploration

In order to investigate the rupture process and acoustic emission characteristics of shale under fluid-solid coupling, the numerical simulation of fluid-solid coupling of the Niutitang Formation shale in different bedding angle in the northern part of the Qianbei area was carried out by RFPA2D-Flow numerical software. Studies have shown that due to the influence of the bedding structure, the compressive strength and elastic modulus of shale show obvious anisotropy. The rupture process of shale can be divided into three stages: elasticity, yielding and destruction. With the change of the bedding angle, the shale finally showed three failure modes, namely oblique …


The Control Of Mineralization And Occurrence Of Coal-Based Graphite By Tectonic-Heat In Zhangping-Datian Area, Fujian, Ding Zhengyun, Wang Lu, Zeng Huan, Li Yang, Chen Quanlin, Deng Ruijin, Cheng Qiao, Lin Xiaoyan, Cao Daiyong Feb 2020

The Control Of Mineralization And Occurrence Of Coal-Based Graphite By Tectonic-Heat In Zhangping-Datian Area, Fujian, Ding Zhengyun, Wang Lu, Zeng Huan, Li Yang, Chen Quanlin, Deng Ruijin, Cheng Qiao, Lin Xiaoyan, Cao Daiyong

Coal Geology & Exploration

Datian-Zhangping area, Fujian Province, is located in the east coast Pacific tectonic belt, magmatic hydrothermal processes and complex tectonic deformation patterns in different periods provide favorable conditions for the formation of abundant graphite deposits in this area. In order to find out the metallogenic control factors and distribution law of coal-based graphite in Datian-Zhangping area, through proximate analysis, elemental analysis, X-ray diffraction and Raman spectroscopy, the graphitization characteristics of coal and coal-based graphite with different metamorphic degree in different mining areas were studied. The samples with different deformation characteristics were divided into three types: coal-based graphite, coal-based semi-graphite and graph-itized …


Gas Content Modeling Of No.3 Coal Seam In District 3 Of Southern Shizhuang Block, Zhou You, Zhang Songhang, Tang Shuheng, Yu Tiancheng, Feng Zhao Feb 2020

Gas Content Modeling Of No.3 Coal Seam In District 3 Of Southern Shizhuang Block, Zhou You, Zhang Songhang, Tang Shuheng, Yu Tiancheng, Feng Zhao

Coal Geology & Exploration

The gas content of coal seam has a direct impact on the development of coalbed methane. The gas content of coal seam in southern Shizhuang block is high, but there are many inefficient wells in the development process, and the 3D geological modeling of gas content can help determine the influence of gas content on the production of CBM wells. In this paper, the research object is the No.3 coal seam in southern Shizhuang block. Calculated gas content from linear multivariate regression by using parameters of ash content, volatile matter content and fixed carbon content and simple burial depth matches …


Thermal Short-Circuiting And Heat Transfer Performance Of Coaxial Borehole Heat Exchanger, Li Yongqiang, Xu Shuanhai, Zhang Weidong, Sun Yuliang, Han Yongliang, Zhang Hao, Huang Jianfeng Feb 2020

Thermal Short-Circuiting And Heat Transfer Performance Of Coaxial Borehole Heat Exchanger, Li Yongqiang, Xu Shuanhai, Zhang Weidong, Sun Yuliang, Han Yongliang, Zhang Hao, Huang Jianfeng

Coal Geology & Exploration

The coaxial heat exchanger is a commonly used device for deep ground source heat pump systems. Based on the fluid flow heat transfer equation, the coupled heat transfer model of the coaxial heat exchanger and the surrounding rock mass is established. Taking the first heating period as an example, the influence of the inner tube thermal conductivity and circulating water flow on the heat transfer performance was analyzed, and the heat exchanger efficiency was introduced to evaluate the thermal short-circuiting phenomenon. The following conclusions were obtained: The phenomenon of thermal short circuit becomes obvious with the increase of the thermal …


Table Of Contents, The Editors Feb 2020

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Geosteering Technology And Cbm Horizontal Well Drilling Without Pilot Hole, Liu Mingjun, Li Bing, Huang Wei Feb 2020

Geosteering Technology And Cbm Horizontal Well Drilling Without Pilot Hole, Liu Mingjun, Li Bing, Huang Wei

Coal Geology & Exploration

Aiming at the difficulties of hole-forming of the horizontal interval in a soft coal seam, low drilling ratio of coal seam and need of pilot hole during deflecting drilling, the key technologies such as drilling parameter optimization, anti-collapse drilling were put forward in the paper. Geosteering technology with multi-markers was used to realize timely layer identification, to search suitable targeting angle, to be adaptive to the stratum dip so as to realize one time direct landing at the target. Geosteering and geometric steering were combined to control finely the wellbore trajectory of the horizontal interval, to make the wellbore trajectory …


Status And Development Prospect Of The Coal-Based Graphite Resources In Fujian Province, Chen Quanlin, Cheng Qiao, Deng Ruijin, Lin Xiaoyan, Wang Lu, Ding Zhengyun, Li Yang, Cheng Qiao, Lin Xiaoyan, Cao Daiyong Feb 2020

Status And Development Prospect Of The Coal-Based Graphite Resources In Fujian Province, Chen Quanlin, Cheng Qiao, Deng Ruijin, Lin Xiaoyan, Wang Lu, Ding Zhengyun, Li Yang, Cheng Qiao, Lin Xiaoyan, Cao Daiyong

Coal Geology & Exploration

The coal-based graphite of Fujian Province occurs in the coal-bearing strata of the Middle Permian Tong ziyan Formation, is formed by the further metamorphism of the anthracite of the Tongziyan Formation under high temperature and pressure, and belongs to the aphanitic graphite. By investigating the distribution characteristics of coal-based graphite in Fujian Province, it was found that most of the coal-based graphite mines and exploration areas are in an unmined or stopped state, and production and sale in most mining areas are in the form of coal mining, causing resources waste. In order to rationally develop and use coal-based graphite …


Raman Spectrum Characteristic And Structural Evolution Of High Rank Coalscryptocrystalline Graphite, Li Huantong, Wang Nan, Zhu Zhirong, Fan Jingjing, Zhang Weiguo Feb 2020

Raman Spectrum Characteristic And Structural Evolution Of High Rank Coalscryptocrystalline Graphite, Li Huantong, Wang Nan, Zhu Zhirong, Fan Jingjing, Zhang Weiguo

Coal Geology & Exploration

Raman spectroscopy can reflect the order degree and structural defects of carbon materials, and can be used to characterize the structural changes during the evolution of high rank coal-cryptocrystalline graphite, and analyze the relationship between Raman parameters of coal with different deformation and metamorphic degrees and the spacing of surface network(d002). The results showed that: (1) there was stepped variation between the G peak position and d002, but the graphite and high rank coal could be distinguished well. The S2 peak, the full width at half maximum of D1 and G had a good linear relationship with d002; (2) the …


Occurrence And Origin Of Graphite Microcrystal In Meta-Anthracite, Li Jiuqing, Qin Yong, Chen Yilin Feb 2020

Occurrence And Origin Of Graphite Microcrystal In Meta-Anthracite, Li Jiuqing, Qin Yong, Chen Yilin

Coal Geology & Exploration

Microcrystalline graphite occurs widely in meta-anthracite,to analyse the occurrence characteristics and genesis of graphite microcrystal, by methods of optical microscope, scanning electron microscope and transmission electron microscope, the optical properties, material composition and crystal structure of graphite microcrystal in Yong’an coal field of Fujian Province were characterized, and their genesis was preliminarily discussed. The results show that the graphite microcrystal in coal occurs mainly in micro cracks and cavities, and most of them have fibrous microstructure similar to petroleum coke, with bubble membrane structure. The maximum reflectivity of the microcrystal ranges from 9.29% to 10.83% and significantly stronger than the …


Molecular Structure Characteristics And Model Construction Of Anthracite In Jarud, Zhang Shuai, Ma Rujia, Liu Lu, Zhang Hao, Liu Qinfu Feb 2020

Molecular Structure Characteristics And Model Construction Of Anthracite In Jarud, Zhang Shuai, Ma Rujia, Liu Lu, Zhang Hao, Liu Qinfu

Coal Geology & Exploration

To construct the macromolecular structure model of anthracite in Jarud of Inner Mongolia, the macromolecule structure of anthracite in this area was investigated using the methods of proximate analysis, ultimate analysis, carbon nuclear magnetic resonance(13C-NMR), high resolution transmission electron microscope(HRTEM), and X-ray photoelectric spectrometry(XPS). The results showed that aromatic carbon was the main component of macromolecule structure. Aliphatic carbon existed mainly in the form of short aliphatic chains and naphthenic hydrocarbons. The oxygen-containing functional groups in macromolecule structure of anthracite existed in the form of phenolic hydroxyl group and ether oxygen group. The nitrogen atoms were mainly in the form …


“Scenario-Response”-Based Emergency Decision-Making Mechanism Of Mine Water Inrush Disaster, Lian Huiqing, Yang Junwen, Han Ruigang, Meng Lu, Han Yong Feb 2020

“Scenario-Response”-Based Emergency Decision-Making Mechanism Of Mine Water Inrush Disaster, Lian Huiqing, Yang Junwen, Han Ruigang, Meng Lu, Han Yong

Coal Geology & Exploration

The urgency, complexity and uncertainty of mine flood accidents determine that traditional emergency decision-making models are difficult to meet the requirements of efficient emergency rescue. Using the “scenario-response” model for emergency decision-making of mine flood accidents can effectively solve the timely real-time decision-making of specific disaster scenario after disasters occur. Using a multi-case analysis method to analyze 11 typical mine flood accidents in recent years, based on the general structural description of the accident, six elements of the mine flood scenario were summarized(inrush water source, water inrush channel, water inrush position, water output, submerged range, living space) as the scenario …


Characteristics And Sedimental Control Of Mine Water Outflow In Hujirt Mining Area, Liang Xiangyang, Yang Jian, Cao Zhiguo Feb 2020

Characteristics And Sedimental Control Of Mine Water Outflow In Hujirt Mining Area, Liang Xiangyang, Yang Jian, Cao Zhiguo

Coal Geology & Exploration

Hujirt mining area in Ordos basin is a deep-buried Jurassic coalfield with high water pressure, large water volume and uneven water abundance. Each mine is facing serious pressure of mine water hazard prevention and control. In order to clarify the water outflow conditions and main controlling factors of the coal seam roof of the mine in this area, the research on geological deposit and water-producing horizon of roof boreholes, water-inrush from boreholes and water-inrush from working face was carried out. The results showed that within the water conducting fractured zone of Hujirt mining area, there are mainly meandering river sedimentary …


Development And Application Of Macroscopic And Mesoscopic Analytical Testing Instrument For Reinforcement-Soil Interface Characteristics, Yi Fu, Du Changbo, Wang Zhengyun, Yu Ben Feb 2020

Development And Application Of Macroscopic And Mesoscopic Analytical Testing Instrument For Reinforcement-Soil Interface Characteristics, Yi Fu, Du Changbo, Wang Zhengyun, Yu Ben

Coal Geology & Exploration

To analyze the interaction characteristics of soil-reinforcement interface more comprehensively, an experimental instrument for macro-and micro-analysis of interface characteristics of visible reinforced soils was developed and can be used for direct shear and pull-out tests with different geosynthetics and fillers. The instrument improves the size of test box, facilitates the comparative analysis of the two tests, and has an image recording system which enables the microscopic analysis of test process. The direct shear and pull-out tests of geosynthe­tics(geogrid and geotextile) reinforced tailings sand were carried out with the newly developed apparatus. The results show that the interface parameters(pseudo-cohesion and pseudo …


Scalable Universal Space Vector Pulse Width Modulation Scheme For Multilevel Inverters, Wei Qiao, Fa Chen, Liyan Qu Feb 2020

Scalable Universal Space Vector Pulse Width Modulation Scheme For Multilevel Inverters, Wei Qiao, Fa Chen, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

A scalable universal space vector pulse-width modulation (SVPWM) scheme for multilevel inverters is disclosed. In the disclosed SVPWM scheme, the modulation triable is quickly identified based on a coordinate transformation from an α-β coordinate system to a 120o oblique coordinate system. Then, the duty cycles and switching states of the three vertices of the modulation triangle are determined by simple algebraic computations. In a switching period, any vertex of the modulation triangle can be flexibly selected as the start point to optimize the switching sequence with flexibly adjustable duty cycle(s) for the redundant switching state(s) according to specific applications.


Millimetre-Wave Planar Bruce Array Antenna, Zeeshan Ahmed, Manh Ha Hoang, Patrick Mcevoy, Max Ammann Feb 2020

Millimetre-Wave Planar Bruce Array Antenna, Zeeshan Ahmed, Manh Ha Hoang, Patrick Mcevoy, Max Ammann

Conference papers

A tri-band mm-wave planar Bruce array antenna for fifth generation communications (5G) is presented. The 16-element planar Bruce array antenna is simulated and fabricated on Rogers RT/Duroid 5880 substrate with thickness of 0.254 mm. For a compact and simple structure, the antenna has a highly directional fan-beam radiation pattern at broadside and peak realized gain of 14.0 dBi.


Aviation Maintenance Safety Management Challenges : Thematic Analysis, Tori Kobayashi, Brent D. Bowen Feb 2020

Aviation Maintenance Safety Management Challenges : Thematic Analysis, Tori Kobayashi, Brent D. Bowen

Student Works

Aircraft maintenance is a fundamental and necessary element in any aviation operation. In order to be considered safe and airworthy, operators must be diligent in the way aircraft are maintained and how employees are performing. A safety management system (SMS) is an organized approach by management to include every employee of a company that standardizes the procedures a company will follow to improve safety. The structure of SMS was designed by the International Civil Aviation Organization in order to be standardized across different countries and types of operations. Currently, only part 121 U.S. commercial airlines are mandated by the Federal …


Living Cell Imaging Technique Sheds Light On Molecular View Of Obesity, Usu College Of Engineering Feb 2020

Living Cell Imaging Technique Sheds Light On Molecular View Of Obesity, Usu College Of Engineering

College of Engineering News

Utah State University researchers develop probes to help improve techniques to test drugs for obesity-related conditions.


Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple Feb 2020

Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple

Faculty Publications

Radio frequency (RF) fingerprinting extracts fingerprint features from RF signals to protect against masquerade attacks by enabling reliable authentication of communication devices at the “serial number” level. Facilitating the reliable authentication of communication devices are machine learning (ML) algorithms which find meaningful statistical differences between measured data. The Generalized Relevance Learning Vector Quantization-Improved (GRLVQI) classifier is one ML algorithm which has shown efficacy for RF fingerprinting device discrimination. GRLVQI extends the Learning Vector Quantization (LVQ) family of “winner take all” classifiers that develop prototype vectors (PVs) which represent data. In LVQ algorithms, distances are computed between exemplars and PVs, and …


A Qualitative Assessment Of Airline Passenger Satisfaction, Kaetlyn Blocker, Brent D. Bowen, Erin Bowen, Andrea Irish Feb 2020

A Qualitative Assessment Of Airline Passenger Satisfaction, Kaetlyn Blocker, Brent D. Bowen, Erin Bowen, Andrea Irish

Student Works

Each year, airline passengers respond to the Airline Passenger Survey providing feedback of their experiences with major domestic (U.S.) airlines. The Airline Passenger Survey analyzes responses to a varied set of questions. This specific study is limited to the single open-ended question within the survey. This question is optional, but allows an opportunity to share any issues, concerns, and/or complaints regarding their own air travel experiences. There is no limitation on the number of words submitted. Through the application of a thematic coding scheme, results show what the highest concerns of airline passengers have been the last two years.


Effects Of Intrinsic Defects And Alloying With Fe On The Half-Metallicity Of Co2Mnsi, G. G. Baez Flores, Ivan A. Zhuravlev, Kirill Belashchenko Feb 2020

Effects Of Intrinsic Defects And Alloying With Fe On The Half-Metallicity Of Co2Mnsi, G. G. Baez Flores, Ivan A. Zhuravlev, Kirill Belashchenko

Kirill Belashchenko Publications

The electronic structure and half-metallic gap of Co2MnSi in the presence of crystallographic defects, partial Fe substitution for Mn, and thermal spin fluctuations are studied using the coherent potential approximation and the disordered local moment method. In the presence of 5% Co or Mn vacancies the Fermi level shifts down to the minority-spin valence-band maximum. In contrast to NiMnSb, both types of Mn antisite defects in Co2MnSi are strongly exchange coupled to the host magnetization, and thermal spin fluctuations do not strongly affect the half-metallic gap. Partial substitution of Mn by Fe results in considerable changes in the Bloch spectral …


Reliability Analysis Of Power Grids And Its Interdependent Infrastructures: An Interaction Graph-Based Approach, Upama Nakarmi Feb 2020

Reliability Analysis Of Power Grids And Its Interdependent Infrastructures: An Interaction Graph-Based Approach, Upama Nakarmi

USF Tampa Graduate Theses and Dissertations

Large blackouts with significant societal and economic impacts result from cascade of failures in the transmission network of power grids. Understanding and mitigating cascading failures in power grids is challenging due to the large number of components and their complex interactions, wherein, in addition to the physical topology of the system, the physics of power flow and functional dependencies among components largely affect the spatial distribution and propagation of failures. In this dissertation, data-driven interaction graphs, which help in capturing the underlying interactions and influences among the components during cascading failures, are used for capturing the non-local nature of propagation …


Novel On-Chip Optical Modulator Designs, Mohamed Mahmoud Ibrahim Ibrahim Elsayed Feb 2020

Novel On-Chip Optical Modulator Designs, Mohamed Mahmoud Ibrahim Ibrahim Elsayed

Theses and Dissertations

The huge increments in data traffic and communication over the past few decades have pushed the conventional electronic communication systems to their physical limits in terms of data rate, bandwidth and capacity. The continuous shrinking of feature sizes, the increase in the microelectronic integrated circuits complexity, and the increasing demand for higher speeds and data rates have all stimulated seeking new technology to replace the currently present microelectronics industry rather than improving it. Photonics is one of the most likely candidates to answer this pursuit for its compatibility with the fiber optic industry, which has shown a great success in …