Engineering Commons^™

Replication Data For: Evaporation From Undulating Soil Surfaces Under Turbulent Airflow Through Numerical And Experimental Approaches, Bo Gao, Kathleen Smits, John Farnsworth

Earth & Environmental Sciences Datasets - Archive

Evaporation from undulating soil surfaces is rarely studied due to limited modeling theory and inadequate experimental data linking dynamic soil and atmospheric interactions. The goal of this paper is to provide exploratory insights into evaporation behavior from undulating soil surfaces under turbulent conditions through numerical and experimental approaches. A previously developed and verified coupled free flow and porous media flow model was extended by incorporating turbulent airflow through Reynolds-averaged Navier–Stokes equations. The model explicitly describes the relevant physical processes and the key properties in the free flow, porous media, and at the interface, allowing for the analysis of coupled exchange …

Replication Data For: Effect Of Varying Atmospheric Conditions On Methane Boundary-Layer Development In A Free Flow Domain Interfaced With A Porous Media Domain, C. T.K.K. Deepagoda, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

Mitigation of atmospheric emission of methane from leaky underground infrastructure is important for controlling the global anthropogenic greenhouse gas burden. Overexposure to methane may also cause occupational health problems in indoor/outdoor environments at the local scale. Subsurface soil conditions (e.g. soil heterogeneity) affect methane migration in soils while near-surface atmospheric boundary conditions (e.g. wind and temperature) affect off-site emissions across the soil-atmosphere interface. This study investigated the above-surface methane concentration boundary-layer development under different soil conditions (homogenous and layered) and atmospheric boundary controls (wind and temperature). A series of controlled bench-scale experiments was conducted using an open-loop boundary-layer wind tunnel …

Replication Data For: Thermal Conductivity Of Binary Sand Mixtures Evaluated Through Full Water Content Range, Benjamin Wallen, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

A soil's grain-size distribution affects its physical and hydraulic properties; however, little is known about its effect on soil thermal properties. To better understand how grain-size distribution affects soil thermal properties, specifically the effective thermal conductivity, a set of laboratory experiments was performed using binary mixtures of two uniform sands tightly packed with seven different mixing fractions over the full range of saturation. For each binary mixture, the effective thermal conductivity, λ, capillary pressure, hc, and volumetric water content, θ, were measured. Results demonstrated that the λ–θ relationship exhibited distinct characteristics based on the percentage of fine- and coarse-grained sands. …

Effects Of Tendon Viscoelasticity On The Distribution Of Forces Across Sutures In A Model Tendon-To-Bone Repair, Yuxuan Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tears to the rotator cuff often require surgical repair. These repairs often culminate in re-tearing when sutures break through the tendon in the weeks following repair. Numerous studies have been performed to identify suturing strategies that reduce this risk by balancing forces across sutures. However, the structural engineering basis for these approaches is still emerging, and the effects of tendon mechanics on load balancing is still unclear. Specifically, the effects of the viscoelastic nature of tendon on load sharing have not been established. With the aim of providing insight into this problem, this thesis studies how tendon viscoelasticity, tendon stiffness, …

Replication Data For: Characterization Of Grain-Size Distribution, Thermal Conductivity, And Gas Diffusivity In Variably Saturated Binary Sand Mixtures, C. T.K.K. Deepagoda, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

Characterization of differently textured porous materials, as well as different volumetric porous media mixtures, in relation to mass and heat transport is vital for many engineering and research applications. Functional relations describing physical (e.g., grain-size distribution, total porosity), thermal, and gas diffusion properties of porous media and mixtures are necessary to optimize the design of porous systems that involve heat and gas transport processes. However, only a limited number of studies provide characterization of soil physical, thermal, and gas diffusion properties and the functional relationships of these properties under varying soil water contents, especially for soil mixtures, complicating optimization efforts. …

Single-Rail Adiabatic Logic For Energy-Efficient And Cpa-Resistant Cryptographic Circuit In Low-Frequency Medical Devices, Amit Degada, Himanshu Thapliyal

Electrical and Computer Engineering Graduate Research

Designing energy-efficient and secure cryptographic circuits in low-frequency medical devices are challenging due to low-energy requirements. Also, the conventional CMOS logic-based cryptographic circuits solutions in medical devices can be vulnerable to side-channel attacks (e.g. correlation power analysis (CPA)). In this article, we explored single-rail Clocked CMOS Adiabatic Logic (CCAL) to design an energy-efficient and secure cryptographic circuit for low-frequency medical devices. The performance of the CCAL logic-based circuits was checked with a power clock generator (2N2P-PCG) integrated into the design for the frequency range of 50 kHz to 250 kHz. The CCAL logic gates show an average of approximately 48% …

Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal, John M. Dickens, Lance Champaign, Aaron V. Glassburner, Jason R. Anderson, Timothy W. Breitbach

Faculty Publications

Purpose — Forecasting techniques improve supply chain resilience by ensuring that the correct parts are available when required. In addition, accurate forecasts conserve precious resources and money by avoiding new start contracts to produce unforeseen part requests, reducing labor intensive cannibalization actions and ensuring consistent transportation modality streams where changes incur cost. This study explores the effectiveness of the United States Air Force’s current flying hour-based demand forecast by comparing it with a sortie-based demand forecast to predict future spare part needs. Design/methodology/approach — This study employs a correlation analysis to show that demand for reparable parts on certain aircraft …

Tooth Position Determination By Automatic Cutting And Marking Of Dental Panoramic X-Ray Film In Medical Image Processing, Yen-Cheng Huang, Chiung-An Chen, Tsung-Yi Chen, He-Sheng Chou, Wei-Chi Lin, Tzu-Chien Li, Jia-Jun Yuan, Szu-Yin Lin, Chun-Wei Li, Shih-Lun Chen, Yi-Cheng Mao, Patricia Angela R. Abu, Wei-Yuan Chiang, Wen-Shen Lo

Department of Information Systems & Computer Science Faculty Publications

This paper presents a novel method for automatic segmentation of dental X-ray images into single tooth sections and for placing every segmented tooth onto a precise corresponding position table. Moreover, the proposed method automatically determines the tooth’s position in a panoramic X-ray film. The image-processing step incorporates a variety of image-enhancement techniques, including sharpening, histogram equalization, and flat-field correction. Moreover, image processing was implemented iteratively to achieve higher pixel value contrast between the teeth and cavity. The next image-enhancement step is aimed at detecting the teeth cavity and involves determining the segment and points separating the upper and lower jaw, …

Revised Semiempirical Approach To Predict The Occurrence Of Twinning In Titanium Alloys, Chirag Dhirajlal Rabadia, Syed Faraz Jawed, Jincheng Wang, Milind Siddhpura, Arti Siddhpura

Research outputs 2014 to 2021

A revised semiempirical approach, considering the average values of the valence electron to atom ratio (e/a̅) and a difference in atomic radii of alloying element/s and the base element (Δr¯), is proposed to predict the twin formation in titanium alloys. The revised e/ā versus Δr¯ diagram is plotted, considering the reported results of 90 titanium alloys fabricated using various processing methods. A new twin/slip boundary has been plotted and recommended based on the revised e/ā versus Δr¯ diagram. The conventional maximum limit reported for the twinning in titanium alloys is e/ā = 4.20; however, it has been found that twinning …

A Geometric Approach To Multiple Target Tracking Using Lie Groups, Mark E. Petersen

Theses and Dissertations

Multiple target tracking (MTT) is the process of localizing targets in an environment using sensors that perceive the environment. MTT has many applications such as wildlife monitoring, air traffic monitoring, and surveillance. These applications motivate further research in the different challenging aspects of MTT. One of these challenges that we will focus on in this dissertation is constructing a high fidelity target model. A common approach to target modeling is to use linear models or other simplified models that do not properly describe the target's pose (position and orientation), motion, and uncertainty. These simplified models are typically used because they …

Modeling The Effects Of Parameter Changes On Heating And Pressure At The Weld Interface And Joint Strength In Friction Bit Joining, Adam Hartly Wagner

Theses and Dissertations

Joining of dissimilar metals is a process that is of interest in many fields, especially the automotive industry where lightweighting of the body structure is important. However, creating strong joints between dissimilar metals can be challenging. Friction bit joining (FBJ) is a solid-state method that uses a consumable bit to create a strong joint between dissimilar metals such as aluminum and steel. The purpose of this research is to gain understanding of how adjusting FBJ parameters affects the heating and pressure at the weld interface using a modeling approach, in order to better understand the bonding process. The questions guiding …

Cross-Checking Automated Passenger Counts For Ridership Analysis, Simon Berrebi, Sanskruti Joshi, Kari Watkins

Journal of Public Transportation

Due to concerns about data quality, Automated Passenger Counting technology has rarely been used to analyze local ridership trends. This paper presents a novel framework to test the consistency and completeness of passenger count data in four cities. The data are aggregated at the system level and compared with the National Transit Database between 2012 and 2018. In all four agencies, passenger counts closely follow the fluctuations observed in the national transit database. There is, however, a slight drift in two of the four agencies. At the stop-level, missing and duplicate vehicle-trips are identified using schedule data from the General …

The Impact Of Inkjet Parameters And Environmental Conditions In Binder Jetting Additive Manufacturing, Trenton Miles Colton

Theses and Dissertations

Binder jetting is an additive manufacturing process in which a part is fabricated layer-by-layer using inkjet technology to selectively dispense binder into powder layers in a designated area. The approach gives this process significant advantages over other additive manufacturing processes such as lower cost, capability to print in a wide range of materials, and little to no heat applied. Although binder jetting has many advantages and has been successful implemented in various industries its overall rate of adoption is slow compared to other processes. This is largely due to poor mechanical properties and consistency in printing which stems from a …

Undersea Cables: The Ultimate Geopolitical Chokepoint, Bert Chapman

FORCES Initiative: Strategy, Security, and Social Systems

This work provides historical and contemporary overviews of this critical geopolitical problem, describes the policy actors addressing this in the U.S. and selected other countries, and provides maps and information on many undersea cable work routes. These cables are chokepoints with one dictionary defining chokepoints as “a strategic narrow route providing passage through or to another region."

Continental Magmatism And Uplift As The Primary Driver For First-Order Oceanic 87sr/86sr Variability With Implications For Global Climate And Atmospheric Oxygenation, Timothy Paulsen, Chad Deering, Jakub Sliwinski, Snehamoy Chatterjee, Olivier Bachman

Michigan Tech Publications, Part 1

Oceans cover 70% of Earth's surface, setting it apart from the other terrestrial planets in the solar system, but the mechanisms driving oceanic chemical evolution through time remain an important unresolved problem. Imbalance in the strontium cycle, introduced, for example, by increases in continental weathering associated with mountain building, has been inferred from shifts in marine carbonate 87Sr/86Sr ratios. There are, however, uncertainties about the spatial and temporal patterns of crustal evolution in Earth's past, particularly for the period leading up to the Cambrian explosion of life. Here we show that U-Pb age and trace element data from a global …

Reduced-Order Dynamic Modeling And Robust Nonlinear Control Of Fluid Flow Velocity Fields, Anu Kossery Jayaprakash, William Mackunis, Vladimir Golubev, Oksana Stalnov

Publications

A robust nonlinear control method is developed for fluid flow velocity tracking, which formally addresses the inherent challenges in practical implementation of closed-loop active flow control systems. A key challenge being addressed here is flow control design to compensate for model parameter variations that can arise from actuator perturbations. The control design is based on a detailed reduced-order model of the actuated flow dynamics, which is rigorously derived to incorporate the inherent time-varying uncertainty in the both the model parameters and the actuator dynamics. To the best of the authors’ knowledge, this is the first robust nonlinear closed-loop active flow …

Spline-Based Contact: Algorithms And Applications, Pulama Bhattacharya

Theses and Dissertations

Contact is one of the most challenging nonlinearities to solve in solid mechanics. In traditional linear finite element analysis, the contact surface is only C^0 continuous, as a result, the normal to the contact surface is not continuous. The normal contact force is directed along the normal in the direction of the contact surface, and therefore, the contact force is discontinuous. This issue is tackled in linear finite element analysis using various surface smoothing techniques, however, a better solution is to use isogeometric analysis where the solution space is spanned by smooth spline basis functions. Unfortunately, spline-based isogeometric contact analysis …

Defining And Detecting Toxicity On Social Media: Context And Knowledge Are Key, Amit Sheth, Valerie Shalin, Ugur Kursuncu

Publications

As the role of online platforms has become increasingly prominent for communication, toxic behaviors, such as cyberbullying and harassment, have been rampant in the last decade. On the other hand, online toxicity is multi-dimensional and sensitive in nature, which makes its detection challenging. As the impact of exposure to online toxicity can lead to serious implications for individuals and communities, reliable models and algorithms are required for detecting and understanding such communications. In this paper We define toxicity to provide a foundation drawing social theories. Then, we provide an approach that identifies multiple dimensions of toxicity and incorporates explicit knowledge …

Pertumbuhan Dan Hasil Dua Kultivar Bayam Pada Sistem Budidaya Hidroponik Untuk Lahan Sempit, Syariful Mubarok, Asyifa Mardatillah, Anne Nuraini

Jurnal Kultivasi

Hidroponik merupakan salah satu teknik sistem budidaya yang biasa digunakan di lahan sempit seperti di perkotaan. Tujuan dari penelitian ini adalah untuk menentukan sistem budidaya bayam yang paling baik untuk diterapkan pada sistem urban farming pada lahan sempit, misalnya di kawasan pemukiman padat penduduk di bagian timur Jakarta. Rancangan Acak Kelompok Lengkap yang digunakan dalam penelitian ini terdiri dari dua kultivar bayam dan tiga sistem budidaya yaitu budidaya konvensional, sistem hidroponik Wick dan NFT. Hasil penelitian menunjukkan bahwa sistem NFT menghasilkan pertumbuhan dan hasil terbaik yang ditunjukkan oleh jumlah daun, diameter batang, luas daun, panjang akar, volume akar dan berat …

A Systematic Review On Blockchain In Education: Opportunities And Challenges, Navin Duwadi, Navin Duwadi

School of Information Systems and Technology Publications

This study focuses on bloackchain as an emerging technology regarding its use to restructure the systems and advance education upon quality outcomes. What are the benefits of integrating blockchain in education concerning system reformation and advancement in developing better educational process for all encompassing learning outcomes? With the recent developments of blockchain applications across multiple domains, the education industry seems to be benefited from this technology in considerable degree. Transcripts and certificates play a vital role in individual’s life so it needs to be stored in tamper-proof and long term available ledger. In pursuant to addressing afore stated question, this …

A Systematic Review On Blockchain In Education: Opportunities And Challenges, Navin Duwadi

Walden Faculty and Staff Publications

This study focuses on bloackchain as an emerging technology regarding its use to restructure the systems and advance education upon quality outcomes. What are the benefits of integrating blockchain in education concerning system reformation and advancement in developing better educational process for all encompassing learning outcomes? With the recent developments of blockchain applications across multiple domains, the education industry seems to be benefited from this technology in considerable degree. Transcripts and certificates play a vital role in individual’s life so it needs to be stored in tamper-proof and long term available ledger. In pursuant to addressing afore stated question, this …

Managing And Utilizing Big Data In Atmospheric Monitoring Systems For Underground Coal Mines, Juan Diaz, Zach Agioutantis, Dionissios T. Hristopulos, Steven Schafrik

Mining Engineering Faculty Publications

Underground coal mining Atmospheric Monitoring Systems (AMS) have been implemented for real-time or near real-time monitoring and evaluation of the mine atmosphere and related parameters such as gas concentration (e.g., CH₄, CO, O₂), fan performance (e.g., power, speed), barometric pressure, ambient temperature, humidity, etc. Depending on the sampling frequency, AMS can collect and manage a tremendous amount of data, which mine operators typically consult for everyday operations as well as long-term planning and more effective management of ventilation systems. The raw data collected by AMS need considerable pre-processing and filtering before they can be used for …

Net-Zero Energy Districts And The Grid: An Energy-Economic Feasibility Case-Study Of The National Western Center In Denver, Co, Usa, Ben Saarloos, Jason C. Quinn

Faculty Work Comprehensive List

Given the enormous impact of buildings on energy consumption, it is important to continue the development of net-zero energy districts. Opportunities exist for energy efficiency and renewable energy on a district level that may not be feasible in individual buildings. Due to the intermittent nature of many renewable energy sources, net-zero energy districts are dependent on the energy grid. The novelty of this work is to quantify and optimize the economic cost and grid independence of a net-zero energy district using the National Western Center (NWC) in Denver, CO, USA as a case study. The NWC is a 100+ ha …

Gis-Based Volunteer Cotton Habitat Prediction And Plant-Level Detection With Uav Remote Sensing, Tianyi Wang, Xiaohan Mei, J. Alex Thomasson, Chenghai Yang, Xiongzhe Han, Pappu Kumar Yadav, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Volunteer cotton plants germinate and grow at unwanted locations like transport routes and can serve as hosts for a harmful cotton pests called cotton boll weevils. The main objective of this study was to develop a geographic information system (GIS) framework to efficiently locate volunteer cotton plants in the cotton production regions in southern Texas, thus reducing time and economic cost for their removal. A GIS network analysis tool was applied to estimate the most likely routes for cotton transportation, and a GIS model was created to identify and visualize potential areas of volunteer cotton growth. The GIS model indicated …

Polymeric Nanofibers Supported Metal Oxides For Electrochemical Energy Storage Devices, Rutul Patel

Electronic Theses & Dissertations

With increasing demand for energy, there is an increased need to find effective ways to store the available energy to sustain current and future generations. Thus, the research investigates whether polymetric nanofibers support metal oxide are a good solution to store energy. The materials used for synthesis includes N-dimethylformamide, nickel nitrate, cobalt nitrate and polyacrylonitrile.

These fibers are developed three phases. First, a homogenous mixture is prepared, followed by electrospinning of the mixture. Next, calcination of the prepared nanofibers was done to generate the 1D nanofibers embedded with metal oxides. The samples are primarily tested for supercapacitor applications, hydrogen evolution …

Machine Learning Approach To Stability Analysis Of Semiconductor Memory Element, Ravindra Thanniru, Gautam Kapila, Nibhrat Lohia

SMU Data Science Review

Memory stability analysis traditionally relied heavily on circuit simulation-based approaches that run Monte Carlo (MC) analysis over various manufacturing and use condition parameters. This paper researches application of Machine Learning approaches for memory element failure analysis which could mimic simulation-like accuracy and minimize the need for engineers to rely heavily on simulators for their validations. Both regressor and classifier algorithms are benchmarked for accuracy and recall scores. A high recall score implies fewer escapes of fails to field and is the metric of choice for comparing algorithm. The paper identifies that recall score in excess of 0.97 can be achieved …

Modeling Electric Energy Generation In Ercot During Extreme Weather Events And The Impact Renewable Energy Has On Grid Reliability, Adam R. Ruthford, Bivin Sadler

SMU Data Science Review

This paper shows the inadequacy of current grid backup supplies, their ongoing threat to grid reliability, and the increased risk of customer blackouts. This paper also examines reliability concerns caused by renewable energy sources under more normal operating conditions. This paper seeks to model the impacts of extreme weather on ERCOTs grid. Unusual weather patterns require that the electrical grid operates in conditions outside normal operating parameters. Electrical system demand can spike well above normal levels. At the same time, weather influences can change the operating envelope of electrical generation equipment. The ERCOT grid has changed from its’ traditional mix …

Design Methodology For Input Shapers Using Genetic Algorithms In Flexible Nonlinear Systems, Mohab Adel Hakim Meshreki

Archived Theses and Dissertations

No abstract provided.

End Milling Process Modeling Using Artificial Neural Networks, Khaled Abdel-Hamid Elsayed

Archived Theses and Dissertations

No abstract provided.

Assessment Of Residential Drinking Water Quality In Maadi, Egypt, Sally Fadel Naguib El Komos

Archived Theses and Dissertations

No abstract provided.