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2022

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Full-Text Articles in Engineering

Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany Nov 2022

Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany

Future Engineering Journal

Expanding the usage of renewable energy in islanded microgrids leads to a reduction in its total inertia. Low inertia microgrids have difficulties in voltage and frequency control. That affected saving its stability and preventing a blackout. To improve low inertia islanded microgrids' dynamic response and save their stability, this paper presented relative rate observer self-tuning fuzzy PID (RROSTF-PID) based on virtual inertia control (VIC) for an islanded microgrid with a high renewable energy sources (RESs) contribution. RROSTF-PID based on VIC's success in showing remarkable improvement in the microgrid's dynamic response and enhancement of its stability. Moreover, it handles different contingency …


Studying Changes And Addressing The Effects Of The Covid-19 Pandemic On Restaurants, Nael Mohamed Nabil Alsarrag Nov 2022

Studying Changes And Addressing The Effects Of The Covid-19 Pandemic On Restaurants, Nael Mohamed Nabil Alsarrag

BAU Journal - Creative Sustainable Development

Several everyday activities were majorly affected by the COVID-19 pandemic, adapting these activities to become safe for people to perform and become "covid-friendly" required many studies. Dining out in restaurants was one of the major activities that were affected by this pandemic. Permanently or partially closed, restaurants adapted quickly to sidewalk pickups, and excessive delivery demand, and accordingly, their menus and even the staffing were shortened. Several months later, the foodservice industry was one of the first to move a step forward against coronavirus and positively adapt by coming up with creative and innovative ways to be able to re-open …


Architectural Representations Of Human Rights, El-Bastawissi Y. Ibtihal, Youssef Maged Nov 2022

Architectural Representations Of Human Rights, El-Bastawissi Y. Ibtihal, Youssef Maged

BAU Journal - Creative Sustainable Development

The United Nations defines the Human Rights as the rights of all human beings, regardless of race, gender, language, religion, nationality, or any other status. These rights include all claims to live freely, to educate and work in equality, and to inhabit humanistic urban and architectural spaces. Throughout the history of architecture, civilisations have generated different perspectives towards respecting the human rights. Temples of Ancient Egyptian Architecture crushed the human scale to introduce religious experiences to their visitors. Tibetan temples over mountains enforced people to make anti-humanistic journeys to reach them. After thousands of years, the mega-scale palaces and cathedrals …


Designing Vr Games To Improve Engagement With At-Home Physical Therapy, Andrada Pantelimon Nov 2022

Designing Vr Games To Improve Engagement With At-Home Physical Therapy, Andrada Pantelimon

ENGS 88 Honors Thesis (AB Students)

Musculoskeletal (MSK) conditions are the leading cause of disability worldwide. Every year, 50% of American adults over 18 years-old develop an MSK condition that requires physical therapy (PT). However, only about 35% of patients fully adhere to their plans of treatment. As the population ages and telehealth permeates the PT industry, there is a growing need as well as an opportunity to use new and emerging technologies to create immersive interfaces that increase motivation. This thesis explores the potential VR-based gameful experiences to improve engagement and follow-through with at-home physical therapy for ACL injury, a common acute MSK condition that …


2022 Fall Engr333 Seminar Presentation, Jordan Tuter, Aidan Bakker, Samuel Hoover, Jessica Camp Nov 2022

2022 Fall Engr333 Seminar Presentation, Jordan Tuter, Aidan Bakker, Samuel Hoover, Jessica Camp

ENGR 333

File for student presentation on Carbon Neutrality for Calvin University, given by students in the Fall 2022 class of ENGR333.


Research On Stability And Resilience Of Modern Power Systems, Yi Zhou Nov 2022

Research On Stability And Resilience Of Modern Power Systems, Yi Zhou

USF Tampa Graduate Theses and Dissertations

With more and more renewable energy generation integrated into the utility grid, the modern power system circumstance and its operating characteristics have changed significantly. Since most renewable energy resources are inverter-based resources (IBR), the prominent characteristics of the power electronics and the cyber distribution in the renewable energy generation system make the power grid stability more diverse and complex.

This dissertation addresses the power system resilience problems from two points of view. The first one is from the inverter level, which deals with the problems of short circuit ratio (SCR) drop. With low SCR, the IBR system operation point may …


A Pipeline To Generate Deep Learning Surrogates Of Genome-Scale Metabolic Models, Achilles Rasquinha Nov 2022

A Pipeline To Generate Deep Learning Surrogates Of Genome-Scale Metabolic Models, Achilles Rasquinha

School of Computing: Dissertations, Theses, and Student Research

Genome-Scale Metabolic Models (GEMMs) are powerful reconstructions of biological systems that help metabolic engineers understand and predict growth conditions subjected to various environmental factors around the cellular metabolism of an organism in observation, purely in silico. Applications of metabolic engineering range from perturbation analysis and drug-target discovery to predicting growth rates of biotechnologically important metabolites and reaction objectives within dierent single-cell and multi-cellular organism types. GEMMs use mathematical frameworks for quantitative estimations of flux distributions within metabolic networks. The reasons behind why an organism activates, stuns, or fluctuates between alternative pathways for growth and survival, however, remain relatively unknown. GEMMs …


Characterization Of Materials Properties In Additively Manufactured Aisi-420 Martensitic Steel Deposited By Laser Engineered Net Shaping, Md Mehadi Hassan Nov 2022

Characterization Of Materials Properties In Additively Manufactured Aisi-420 Martensitic Steel Deposited By Laser Engineered Net Shaping, Md Mehadi Hassan

Nanoscience and Microsystems ETDs

Metal additive manufacturing (AM) is a disruptive technology enabling the fabrication of complex and near-net-shaped parts by adding material layer-wise. It offers reduced lead production time. AM processes are finding applications in many industrial sectors such as aerospace, automotive, biomedical, and mold tooling. Despite the tremendous advantages of AM, some challenges still prevent this technology's adoption in high-standard applications. Anisotropy and inhomogeneity in the mechanical properties of the as-built parts and the existence of pores and lack-of-fusion defects are considered the main issues in directed energy deposition (L-DED) parts. Laser-engineered net shaping LENS® offers excellent possibilities to fabricate metal tools …


Backpack Effects On Two-Dimensional Gait Spatiotemporal And Kinematic Parameters, Nardo Rizaldy, Alvin Alvin, Wirawan Lingga, Ethan B.W. Goeij, F. Ferryanto Nov 2022

Backpack Effects On Two-Dimensional Gait Spatiotemporal And Kinematic Parameters, Nardo Rizaldy, Alvin Alvin, Wirawan Lingga, Ethan B.W. Goeij, F. Ferryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Loads could affect the body gait in various ways. Backpacks, sling bags, suitcases, and even trolleys could hugely affect human gait without us realizing it. The effects of these loads have been scientifically researched in biomechanics and sports science for the past few years. For instance, the comparison of walking with and without a backpack could easily reveal significant differences in body segments, which could be utilized for therapy and medicine development. The aim of this research is to determine the differences of the spatiotemporal kinematic parameters between a conventional human gait and a backpackloaded gait. Some parameters to be …


Investigate The Potential Renewable Energy Of Microalgae Spirulina Sp Using Proximate Analyzer, Sem-Edx, And Thermogravimetry, Yahya Zakaria, Sukarni Sukarni, Poppy Puspitasari, Nandang Mufti, Samsudin Anis, Anwar Johari Nov 2022

Investigate The Potential Renewable Energy Of Microalgae Spirulina Sp Using Proximate Analyzer, Sem-Edx, And Thermogravimetry, Yahya Zakaria, Sukarni Sukarni, Poppy Puspitasari, Nandang Mufti, Samsudin Anis, Anwar Johari

Journal of Mechanical Engineering Science and Technology (JMEST)

Microalgae Spirulina sp which has been cultivated by the Brackishwater Aquaculture Development Center, Situbondo Indonesia were tested for their potential energy performance using proximate analyzer, SEMEDX, and thermogravimetry. The proximate analyzer showed volatile matter (VM), fixed carbon (FC), moisture, ash content (AC), total sulfur of microalgae Spirulina sp 68.15, 12.57, 11.22, 8.06, and 0.67 (wt%, ar), respectively, and the gross calorific value (GCV) is 4971 kcal/kg (dry basis). SEM-EDX test showed the morphology and chemical content of Spirulina sp. The content of microalgae Spirulina sp is dominated by carbon (C) and oxygen (O), then followed by chlorine (Cl), sodium (Na), …


The Effect Of Nozzle Temperature, Infill Geometry, Layer Height And Fan Speed On Roughness Surface In Petg Filament, Doohan Taqdissillah, Aris Zainul Mutaqqin, Mahros Darsin, Dedi Dwilaksana, Nasrul Ilminnafik Nov 2022

The Effect Of Nozzle Temperature, Infill Geometry, Layer Height And Fan Speed On Roughness Surface In Petg Filament, Doohan Taqdissillah, Aris Zainul Mutaqqin, Mahros Darsin, Dedi Dwilaksana, Nasrul Ilminnafik

Journal of Mechanical Engineering Science and Technology (JMEST)

3D printing is a process of making three-dimensional solid objects from a digital file process created by laying down successive layers of material until the object is created. Many filaments can be used in 3D printing, one of which is PETG (PolyEthylene Terephthalate Glycol). PETG is a modification of PET (PolyEthylene Terephthalate) with added glycol at a molecular level to offer different chemical properties that provide significant chemical resistance, durability, and excellent formability for manufacturing. This study aims to find the most optimal parameter of surface roughness of PETG with different parameters of nozzle temperature, infill geometry, layer height and …


Study On Predictive Maintenance Of V-Belt In Milling Machines Using Machine Learning, Reza Aulia Rahman, Mohammad Faishol Erikyatna, Achmad Fauzan Hery Soegiharto Nov 2022

Study On Predictive Maintenance Of V-Belt In Milling Machines Using Machine Learning, Reza Aulia Rahman, Mohammad Faishol Erikyatna, Achmad Fauzan Hery Soegiharto

Journal of Mechanical Engineering Science and Technology (JMEST)

Towards industry 4.0, monitoring the degradation of machine tools’ components becomes a key feature so that smooth productivity is achieved. To preserve the functionality and performance of the machine tools, proper maintenance activities must be planned and carried out. V-belt is important component in machine tools that transmits power from the electric motor spindle in order to machine to work and cut desired material properly. The purpose of this research is to develop a predictive maintenance system for v-belt milling machine Krisbow 31N2F using machine learning. The machine learning algorithm models using multiple and simple linear regression algorithm was developed …


True Stress-Strain Behavior Of Al-Based Cast Automotive Alloy Under Different Ageing Conditions And The Effect Of Trace Zr, Mashiur Rahman Shoummo, Akib Abdullah Khan, Mohammad Salim Kaiser Nov 2022

True Stress-Strain Behavior Of Al-Based Cast Automotive Alloy Under Different Ageing Conditions And The Effect Of Trace Zr, Mashiur Rahman Shoummo, Akib Abdullah Khan, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

A thorough investigation has been carried out on the Al-12Si-1Mg-1Cu-1Ni automotive alloy considering different properties, specially mechanical properties associated with true stress and true strain with Zr addition of trace amount. A commercially available piston is melted to produce the alloy, and trace amount of Zr is added to make another. The base alloy along with the Zr added alloy had been applied to homogenization, solution treatment, quenching, and ageing in order to get the age-hardening response. The alloys have been heat-treated at 25 ºC, 200 ºC, and 300 ºC, respectively, for four hours for attaining the under, peak and …


Effect Of Graphene Addition On Bacterial Cellulose-Based Nanocomposite, Jibril Maulana, Heru Suryanto, Aminnudin Aminnudin Nov 2022

Effect Of Graphene Addition On Bacterial Cellulose-Based Nanocomposite, Jibril Maulana, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Bacterial cellulose (BC) is a widespread, low-cost biopolymer that has generally been produced from plants and biomass waste. A method for improving the range of applications for bacterial cellulose is adding graphene material. It has an outstanding feature that can increase the performance of nanocomposite materials. The research aims to observe the effect of graphene on the surface morphology, crystallinity, chemical bonding, and tensile strength of BC/CuO nanocomposite. For this study's synthesis, BC was synthesized by fermenting pineapple peel extract for 10 to 14 days. The produced BC was crushed, homogenized with a nano homogenizer machine, and filtered. Filtered BC, …


Active Attestation Of Embedded Systems, Mark M. Stephenson, Patrick A. Reber, Patrick J. Sweeney, Scott R. Graham Nov 2022

Active Attestation Of Embedded Systems, Mark M. Stephenson, Patrick A. Reber, Patrick J. Sweeney, Scott R. Graham

AFIT Patents

An active attestation apparatus verifies at runtime the integrity of untrusted machine code of an embedded system residing in a memory device while it is being run/used with while slowing the processing time less than other methods. The apparatus uses an integrated circuit chip containing a microcontroller and a reprogrammable logic device, such as a field programmable gate array (FPGA), to implement software attestation at runtime and in less time than is typically possible with comparable attestation approaches, while not requiring any halt of the processor in the microcontroller. The reprogrammable logic device includes functionality to load an encrypted version …


Data-Driven Analysis For Facility Management In Higher Education Institution, Ashish Kumar Pampana, Jungho Jeon, Soojin Yoon, Theodore J. Weidner, Makarand Hastak Nov 2022

Data-Driven Analysis For Facility Management In Higher Education Institution, Ashish Kumar Pampana, Jungho Jeon, Soojin Yoon, Theodore J. Weidner, Makarand Hastak

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Planned Preventive Maintenance (PPM) and Unplanned Maintenance (UPM) are the most common types of facility maintenance. This paper analyzes current trends and status of Facility Management (FM) practice at higher education institutions by proposing a systematic data-driven methodology using Natural Language Process (NLP) approaches, statistical analysis, risk-profile analysis, and outlier analysis. This study utilizes a descriptive database entitled "Facility Management Unified Classification Database (FMUCD)" to conduct the systematic data-driven analyses. The 5-year data from 2015 to 2019 was collected from eight universities in North America. A preprocessing step included but was not limited to identifying common data attributes, cleaning noisy …


Machine Learning-Based Classification Of Combustion Events In An Rcci Engine Using Heat Release Rate Shapes, Radhika Sitaraman, Sadaf Batool, Hoseinali Borhan, Javad Mohammadpour Velni, Jeffrey Naber, Mahdi Shahbakhti Nov 2022

Machine Learning-Based Classification Of Combustion Events In An Rcci Engine Using Heat Release Rate Shapes, Radhika Sitaraman, Sadaf Batool, Hoseinali Borhan, Javad Mohammadpour Velni, Jeffrey Naber, Mahdi Shahbakhti

Michigan Tech Publications, Part 1

Reactivity controlled compression ignition (RCCI) mode offers high thermal efficiency and low nitrogen oxides (NOx) and soot emissions. However, high cyclic variability at low engine load and high pressure rise rates at high loads limit RCCI operation. Therefore, it is important to control the combustion event in an RCCI engines to prevent abnormal engine combustion. To this end, combustion in RCCI mode was studied by analyzing the heat release rates calculated from the in-cylinder pressure data at 798 different operating conditions. Five distinct heat release shapes are identified. These different heat release traces were characterized based on start of combustion, …


Application Of Uas‑Based Remote Sensing In Estimating Winter Wheat Phenotypic Traits And Yield During The Growing Season, Kianoosh Hassani, Hamed Gholizadeh, Saleh Taghvaeian, Victoria Natalie, Jonathan Carpenter, Jamey Jacob Nov 2022

Application Of Uas‑Based Remote Sensing In Estimating Winter Wheat Phenotypic Traits And Yield During The Growing Season, Kianoosh Hassani, Hamed Gholizadeh, Saleh Taghvaeian, Victoria Natalie, Jonathan Carpenter, Jamey Jacob

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Phenotyping approaches have been considered as a vital component in crop breeding programs to improve crops and develop new high-yielding cultivars. However, traditional field-based monitoring methods are expensive, invasive, and time-intensive. Moreover, data collected using satellite and airborne platforms are either costly or limited by their spatial and temporal resolution. Here, we investigated whether low-cost unmanned/unoccupied aerial systems (UASs) data can be used to estimate winter wheat (Triticum aestivum L.) nitrogen (N) content, structural traits including plant height, fresh and dry biomass, and leaf area index (LAI) as well as yield during different winter wheat growing stages. To achieve …


Efects Of Non‑Newtonian Viscosity On Arterial And Venous Fow And Transport, Sabrina Lynch, Nitesh Nama, C Alberto Figueroa Nov 2022

Efects Of Non‑Newtonian Viscosity On Arterial And Venous Fow And Transport, Sabrina Lynch, Nitesh Nama, C Alberto Figueroa

Department of Mechanical and Materials Engineering: Faculty Publications

It is well known that blood exhibits non-Newtonian viscosity, but it is generally modeled as a Newtonian fluid. However, in situations of low shear rate, the validity of the Newtonian assumption is questionable. In this study, we investigated differences between Newtonian and non-Newtonian hemodynamic metrics such as velocity, vorticity, and wall shear stress. In addition, we investigated cardiovascular transport using two different approaches, Eulerian mass transport and Lagrangian particle tracking. Non-Newtonian solutions revealed important differences in both hemodynamic and transport metrics relative to the Newtonian model. Most notably for the hemodynamic metrics, in-plane velocity and vorticity were consistently larger in …


Cybersecurity And Dynamic Operation In Practice: Equipment Impacts And Safety Guarantees, Kip Nieman, Dominic Messina, Matthew Wegener, Helen Durand Nov 2022

Cybersecurity And Dynamic Operation In Practice: Equipment Impacts And Safety Guarantees, Kip Nieman, Dominic Messina, Matthew Wegener, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Though dynamic operation of chemical processes has been extensively explored theoretically in contexts such as economic model predictive control or even considering the potential for cyberattacks on control systems creating non-standard operating policies, important practical questions remain regarding dynamic operation. In this work, we look at two of these with particular relevance to process safety: (1) evaluating dynamic operating policies with respect to process equipment fidelity and (2) evaluating procedures for determining the parameters of an advanced control law that can promote both dynamic operation as well as safety if appropriately designed. Regarding the first topic, we utilize computational fluid …


Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo Nov 2022

Theory And Experiment Of The Dual-Bit Torque Self-Balancing Drilling System For Rescue Drilling, Gao Ke, Zhang Cong, Zhao Yan, Li Xu, Wen Yumin, Lyu Xiaoshu, Xie Xiaobo

Coal Geology & Exploration

The rapid and safe construction of rescue channel is an effective method to save the trapped person underground after mine accidents. The conventional rescue hole drilling technologies mainly include the downhole hammer percussion drilling technology and the composite drilling technology, which have the disadvantages of large rig structure, complex drilling process, great disturbance to the formation and low target hit rate. In particular, it is easy to have secondary accidents in the fractured strata, and the rescue requirements could not be effectively met. In order to ensure the formation adaptability and wall stability of rescue boreholes, the dual-bit torque self-balancing …


Occurrence Characteristics And Ecological Risk Assessment Of Heavy Metals In Fly Ash Of Ningdong Energy Chemical Industry Base, Zhang Zhiguo, Tan Yuning, Hu Youbiao, Zheng Yonghong, Chen Denghong, Cai Weiqing, Li Yating, Lu Jiangwei Nov 2022

Occurrence Characteristics And Ecological Risk Assessment Of Heavy Metals In Fly Ash Of Ningdong Energy Chemical Industry Base, Zhang Zhiguo, Tan Yuning, Hu Youbiao, Zheng Yonghong, Chen Denghong, Cai Weiqing, Li Yating, Lu Jiangwei

Coal Geology & Exploration

In order to expand the resource utilization of fly ash, research was conducted based on the fly ash of Yuanyang Lake Power Plant in the Ningdong Energy Chemical Industry Base. Specifically, the physical and chemical properties of fly ash were characterized and analyzed by means of scanning electron microscope, energy spectrum analysis and X-ray diffraction. Besides, the total amount, effective state and content in different forms of Pb, Cr, Ni, Cu, Cd and As in fly ash were determined through acid digestion, DTPA extraction and 5-step Tessier sequential extraction. In addition, the ecological risk of heavy metals in fly ash …


Investigation Of Mechanical Properties Of Recycled Fiber-Reinforced Polymer Composites Reinforcing Cement, Caleb Mull, Fnu Archie, Harry Lee, Guyuan Zhang Nov 2022

Investigation Of Mechanical Properties Of Recycled Fiber-Reinforced Polymer Composites Reinforcing Cement, Caleb Mull, Fnu Archie, Harry Lee, Guyuan Zhang

Discovery Undergraduate Interdisciplinary Research Internship

The usage of fiber-reinforced polymer composites in various fields has increased significantly due to their advantageous physical and mechanical properties. However, the sustainability of composite parts has not been fully solved for a long time. Most end-of-life (EOL) composite parts have been landfilled without recycling due to the recycling cost and lack of application of recycled composites. Mechanical composite recycling that shred the EOL composite part and reuse it for downgraded applications is one of the most commonly used recycling processes for the EOL composite part. In this research, mechanical composite recycling process was demonstrated for the construction application. The …


Efficient Interface Enabled By Nano-Hydroxyapatite@Porous Carbon For Lithium-Sulfur Batteries, Jia-Yu Wang, Xue-Feng Tong, Qi-Fan Peng, Yue-Peng Guan, Wei-Kun Wang, An-Bang Wang, Nai-Qiang Liu, Ya-Qin Huang Nov 2022

Efficient Interface Enabled By Nano-Hydroxyapatite@Porous Carbon For Lithium-Sulfur Batteries, Jia-Yu Wang, Xue-Feng Tong, Qi-Fan Peng, Yue-Peng Guan, Wei-Kun Wang, An-Bang Wang, Nai-Qiang Liu, Ya-Qin Huang

Journal of Electrochemistry

The dissolution and “shuttle effect” of lithium polysulfides (LiPSs) hinder the application of lithium-sulfur (Li-S) batteries. To solve those problems, inspired by natural materials, a nano-hydroxyapatite@porous carbon derived from chicken cartilage (nano-HA@CCPC) was fabricated by employing a simple pre-carbonization and carbonization method, and applied in Li-S batteries. The nano-HA@CCPC would provide a reactive interface that allows efficient LiPSs reduction. With a strong affinity for LiPSs and an excellent electronic conductive path for converting LiPSs, the shuttle effect of LiPSs was confined and the redox kinetics of LiPSs was substantially enhanced. Li-S batteries employing nano-HA@CCPC-modified separators exhibited long cycle life and …


Load And Resistance Factor Design (Lrfd) Resistance Factors For Tip Grouted Drilled Shafts, Anhar Sarsour Nov 2022

Load And Resistance Factor Design (Lrfd) Resistance Factors For Tip Grouted Drilled Shafts, Anhar Sarsour

USF Tampa Graduate Theses and Dissertations

Pressure grouting beneath the tip of drilled shafts, also known as postgrouting, has been used for more than fifty years throughout the world and has shown to be an effective means to enhance both the usable and ultimate end bearing resistance. In short, postgrouting is a form of compaction grouting beneath the shaft tip (performed after concrete has cured) that can improve the soil strength and increase the axial shaft stiffness. Until 2006, there was no published design methodology and hence the anticipated performance was speculated to be a function of injected grout volume, shaft uplift and/or the achieved grout …


Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min Nov 2022

Quantitative Experimental Study On Time-Varying Characteristics Of Bleeding Of Cement-Based Grouting Materials, Zhang Runqi, Xu Bin, Yin Shangxian, Li Shuxia, Chang Yongwang, Lian Huiqing, Cao Min

Coal Geology & Exploration

Cement-based cementitious materials are the most common grouting materials for grouting engineering. This type of material has obvious water separation effect, and obtaining the quantitative formula of water separation thickness will be helpful to improve the calculation accuracy of slurry diffusion radius. By observing the water separation process of three admixtures, namely pyrophyllite powder (0%-35%), polyvinyl alcohol (0%-8%) and fly ash (0%-90%) in cement-based slurry, the water separating rate, stone formation rate, final water separation time and water separation thickness of the three admixtures were obtained. It is found that the water separation thickness of the slurry varies regularly with …


Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang Nov 2022

Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang

Coal Geology & Exploration

The ground source heat pump of buried pipeline is a major form of shallow thermal energy utilization, and the thermophysical properties of backfill materials, especially the thermal conductivity, are the key factors affecting the heat transfer efficiency of the heat pump system. In this paper, the variation law of thermal conductivity of the sand-barite powder samples at different barite powder mixing ratio (volume fraction) and saturation was studied. The mechanism of improving the thermal conductivity of backfill materials with barite powder was revealed based on the macroscopic and microscopic experiments such as stereoscope and nuclear magnetic resonance analysis. In addition, …


Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan Nov 2022

Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan

Coal Geology & Exploration

In-Seam Seismic is one of the main detection methods for small geological structures in the coal mining working face. In this method, the energy attenuation feature of in-seam waves is mainly utilized. In case of any significant geological anomaly or receivers coupling difference in coal working face, the energy distribution of the in-seam wave at different frequency bands will be significantly affected, and the stability and accuracy of in-seam wave detection results will be decreased. Using the centroid frequency change features of the in-seam wave signals for inversion imaging is an innovative, effective method. However, for this method, there are …


Recognition Of Modern Modulated Waveforms With Applications To Abms And Vdats Test Program Set Development, Sylwester Sobolewski Nov 2022

Recognition Of Modern Modulated Waveforms With Applications To Abms And Vdats Test Program Set Development, Sylwester Sobolewski

USF Tampa Graduate Theses and Dissertations

A newly developed, near real-time, well-performing and potentially universally applicable Automatic Modulation Recognition (AMR) technique for discrimination of numerous modern modulated waveforms found in commercial as well as military communication systems applicable to the new Air Force’s Advanced Battle Management & Surveillance (ABMS) framework as well as Versatile Depot Automatic Test Station (VDATS) Test Program Set (TPS) development is presented. It involves generating complex feature vectors composed of High-Order Direct Cumulant, Cyclostationary and Fourier of Wavelet Transform features created with the help of Principal Component Analysis and Variance Data Compression.

Twelve modulated waveforms are used to evaluate the performance of …


Frequency Domain Diffuse Optics Spectroscopies For Quantitative Measurement Of Tissue Optical Properties, Sadhu Moka Nov 2022

Frequency Domain Diffuse Optics Spectroscopies For Quantitative Measurement Of Tissue Optical Properties, Sadhu Moka

USF Tampa Graduate Theses and Dissertations

Tissue oxygen saturation, blood flow and blood volume are physiological bio-markers of tissue health. Diffuse Optical Spectroscopy(DOS) and Diffuse Correlation Spectroscopy (DCS) are two complementary approaches to measure tissue oxygen saturation and blood flow respectively. Quantitative Diffuse Optical Spectroscopy (DOS) uses multi-spectral intensities of near-infrared light that have been modulated at RF frequencies to estimate static tissue optical properties and hence concentrations of oxygenated and de-oxygenated hemoglobin. Diffuse Correlation Spectroscopy estimates tissue dynamics - i.e., blood flow, by measuring temporal intensity auto-correlation function of backscattered light diffusing through the tissue. Conventionally, DCS instruments use coherent light sources with constant intensity. …