Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

2019

Discipline
Institution
Keyword
Publication
Publication Type

Articles 11161 - 11190 of 11211

Full-Text Articles in Engineering

Computational Fluid Dynamics Modeling And Comparison Of Advanced Techniques For Heat Transfer Augmentation For Nuclear Applications, Salman Mohammed Alzahrani Jan 2019

Computational Fluid Dynamics Modeling And Comparison Of Advanced Techniques For Heat Transfer Augmentation For Nuclear Applications, Salman Mohammed Alzahrani

Doctoral Dissertations

“Passive safety is the most important feature of NuScale’s reactor designs. Twist tape is one passive heat enhance heat technique. The present research investigated thermo-hydraulic characteristics of natural and forced convection of water under different configurations of twisted tape inserted in tube as well as NuScale rod bundles for uniform wall heat flux using computational fluid dynamics (CFD) using ANSYS Fluent 18.1. Results for twist tape inserted in tube under natural circulation showed that heat transfer enhanced and pressure drop increased to 28% and 102.8% over the plain tube respectively. Regularly spaced tapes, and different widths of the twisted tapes …


On Developing A Graphitic White Iron For Metal-To-Metal Wear Systems, Jie Wan Jan 2019

On Developing A Graphitic White Iron For Metal-To-Metal Wear Systems, Jie Wan

Doctoral Dissertations

"This research addressed heat dissipation issues related to the adhesive wear observed in metal-to-metal wear systems, by developing a graphitic white iron to increase thermal diffusivity of the wear components. One of the premium materials commonly used in current metal-to-metal wear systems is Fe15Mo18Cr and field returned parts were characterized as part of this study. Failure analysis showed that white layers were formed on the wearing surface due to frictional heating and surface deformation. These white layers were extremely brittle and could be fractured easily during use, which in turn led to micro-galling defects that caused parts leakage. Increasing thermal …


Microwave Detection Of Surface Breaking Cracks In Metallic Structures Under Heavy Corrosion And Paint, John Robert Gallion Jan 2019

Microwave Detection Of Surface Breaking Cracks In Metallic Structures Under Heavy Corrosion And Paint, John Robert Gallion

Masters Theses

"We live in the world of "aging infrastructures". In this environment, critical and heavily utilized infrastructure, i.e. ships, planes, bridges, etc., are operating at or beyond their designed age. Replacement is no longer an option and "retirement for cause" is the current approach to maintenance and replacement. Consequently, there is an ever-increasing demand for efficient and robust nondestructive evaluation (NDE) methods that can determine the physical health of these structures. Large structures, which are primarily made of metals, either steel or aluminum, are susceptible to high-stress cracking and corrosion. Stress-induced cracks in heavily corroded steel, used in bridges, railroads, storage …


Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles Jan 2019

Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles

Masters Theses

"This reports the results of experimental studies aimed at characterizing the transport properties of promising adsorbents for various gas capture processes by the "zero length column" (ZLC) technique. ZLC was used to measure the intracrystalline diffusivities of single and binary components of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted)0.5 (Ni-BT) and ZIF-7 for the purpose of olefin/paraffin separation. Results show that binary gaseous systems result in intracrystalline diffusion time constants slightly lower than those in single component gaseous streams due to coadsorption effects. It was also found that ethylene diffusion was affected by surface …


Radiation Immunity In Cable Harnesses And Differential P/N Skew In Pcb, David Nozadze Jan 2019

Radiation Immunity In Cable Harnesses And Differential P/N Skew In Pcb, David Nozadze

Masters Theses

"We develop an efficient method to model RF immunity of multiwire cable harnesses and study differential P/N skew effects on channels, channel performance and specifically on the eye diagrams at the SerDes receiver.

External radiation can induce unwanted signals in transmission lines. For example, external radiation from an antenna induces common-mode currents on the outer surface of cable shields. This common-mode signal makes its way through the shied due to its imperfections, inducing the inner common mode. When twisted pairs inside the cable are not balanced, inner common mode is in turn converted to the differential mode, which might compromise …


Practical Methods For Source Separation In Emc Measurements, Yuanzhuo Liu Jan 2019

Practical Methods For Source Separation In Emc Measurements, Yuanzhuo Liu

Masters Theses

"Electromagnetic emission is critical in the electronic industry with the rapid growth of the development of the electronic device. To identify the emission from the multipule sources, two methods are proposed in the near field scan and total radiated power measurement respectively.

The first method can be applied in the measurement of the field generated by multiple non-correlated sources. The contribution of each source is determined using a blind source separation (BSS) technique. The measurements are performed using one scanning probe and stationary reference probes, avoiding the need to measure the spatial correlations of the random field. The resolving result …


Molecular Dynamics Study Of Creep Deformation In Nickel-Based Superalloy, Sabila Kader Pinky Jan 2019

Molecular Dynamics Study Of Creep Deformation In Nickel-Based Superalloy, Sabila Kader Pinky

MSU Graduate Theses

The present study employs molecular dynamics simulations of Ni-based superalloy to investigate the creep behavior under uniaxial compression test. Dislocation dynamics is analyzed for the nickel-based single crystal superalloy with the presence of void and with varying the distribution of gamma-prime phase The results show that multiple-void systems are more prone to yield than single-void systems and single-void systems are more prone to yield than the system without void. From the simulations, it has been determined that the creep mechanism in Ni/Ni3Al is subject to change on the applied stress depending on the distribution of gamma-prime phases change. Dislocation behavior …


Development Of Multicomponent Eam Potential For Ni-Based Superalloy, Muztoba Rabbani Jan 2019

Development Of Multicomponent Eam Potential For Ni-Based Superalloy, Muztoba Rabbani

MSU Graduate Theses

We initiated the development of multi-component EAM potentials for Aluminides and Carbides, key phases in Ni-based Superalloys. The goal is to utilize the MD simulation to understand the deformation dynamics that contribute to the formation of voids and creep initiation. For this purpose, we constructed the raw data from ab-initio (molecular dynamics) MD simulations fed into the potential development code and used Nickel as the base metal with the addition of a number of various elements including Aluminum, Chromium, Tungsten. We then developed the EAM potentials for the aluminide and carbide phases using the force-fitting code MEAMfit. Our generated potential …


Using Homing, Synchronizing And Distinguishing Input Sequences For The Analysis Of Reversible Finite State Machines, Martin Lukac, Michitaka Kameyama, Marek A. Perkowski, Pawel Kerntopf Jan 2019

Using Homing, Synchronizing And Distinguishing Input Sequences For The Analysis Of Reversible Finite State Machines, Martin Lukac, Michitaka Kameyama, Marek A. Perkowski, Pawel Kerntopf

Electrical and Computer Engineering Faculty Publications and Presentations

A digital device is called reversible if it realizes a reversible mapping, i.e., the one for which there exist a unique inverse. The field of reversible computing is devoted to studying all aspects of using and designing reversible devices. During last 15 years this field has been developing very intensively due to its applications in quantum computing, nanotechnology and reducing power consumption of digital devices. We present an analysis of the Reversible Finite State Machines (RFSM) with respect to three well known sequences used in the testability analysis of the classical Finite State Machines (FSM). The homing, distinguishing and synchronizing …


Machine-Learning Based Three-Qubit Gate For Realization Of A Toffoli Gate With Cqed-Based Transmon Systems, Sahar Daraeizadeh, Shavindra Premaratne, Xiaoyu Song, Marek A. Perkowski, Anne Y. Matsuura Jan 2019

Machine-Learning Based Three-Qubit Gate For Realization Of A Toffoli Gate With Cqed-Based Transmon Systems, Sahar Daraeizadeh, Shavindra Premaratne, Xiaoyu Song, Marek A. Perkowski, Anne Y. Matsuura

Electrical and Computer Engineering Faculty Publications and Presentations

We use machine learning techniques to design a 50 ns three-qubit flux-tunable controlled-controlled-phase gate with fidelity of >99.99% for nearest-neighbor coupled transmons in circuit quantum electrodynamics architectures. We explain our gate design procedure where we enforce realistic constraints, and analyze the new gate’s robustness under decoherence, distortion, and random noise. Our controlled-controlled phase gate in combination with two single-qubit gates realizes a Toffoli gate which is widely used in quantum circuits, logic synthesis, quantum error correction, and quantum games.


Design And Evaluation Of A Non-Contact Bed-Mounted Sensing Device For Automated In-Home Detection Of Obstructive Sleep Apnea: A Pilot Study, Clara Mosquera-Lopez, Joseph Leitschuh, John Condon, Chad C. Hagen, Uma Rajhbeharrysingh, Cody Hanks, Peter Jacobs Jan 2019

Design And Evaluation Of A Non-Contact Bed-Mounted Sensing Device For Automated In-Home Detection Of Obstructive Sleep Apnea: A Pilot Study, Clara Mosquera-Lopez, Joseph Leitschuh, John Condon, Chad C. Hagen, Uma Rajhbeharrysingh, Cody Hanks, Peter Jacobs

Electrical and Computer Engineering Faculty Publications and Presentations

We conducted a pilot study to evaluate the accuracy of a custom built non-contact pressure-sensitive device in diagnosing obstructive sleep apnea (OSA) severity as an alternative to in-laboratory polysomnography (PSG) and a Type 3 in-home sleep apnea test (HSAT). Fourteen patients completed PSG sleep studies for one night with simultaneous recording from our load-cell-based sensing device in the bed. Subjects subsequently installed pressure sensors in their bed at home and recorded signals for up to four nights. Machine learning models were optimized to classify sleep apnea severity using a standardized American Academy of Sleep Medicine (AASM) scoring of the gold …


Aggregation Of Residential Water Heaters For Peak Shifting And Frequency Response Services, Thomas Leighton Clarke, Tylor Slay, Robert B. Bass, Conrad Eustis Jan 2019

Aggregation Of Residential Water Heaters For Peak Shifting And Frequency Response Services, Thomas Leighton Clarke, Tylor Slay, Robert B. Bass, Conrad Eustis

Electrical and Computer Engineering Faculty Publications and Presentations

The increased penetration of renewable energy resources poses challenges for grid stability. The stochastic generation of solar and wind power cannot be controlled to follow load. And, the transition away from synchronous generators is reducing the capacity to arrest and recover from frequency disturbances. Smart electric water heaters provide utilities with an appliance that can be remotely controlled and serve as a form of energy storage. They have very fast response times and make up a large amount of residential energy consumption, making them useful for load peak shifting as well as other ancillary grid services. As smart appliances become …


News - Screven-Jenkins Regional Library, Sharon Blank Jan 2019

News - Screven-Jenkins Regional Library, Sharon Blank

Georgia Library Quarterly

No abstract provided.


Applied Deep Learning In Orthopaedics, William Stewart Burton Ii Jan 2019

Applied Deep Learning In Orthopaedics, William Stewart Burton Ii

Electronic Theses and Dissertations

The reemergence of deep learning in recent years has led to its successful application in a wide variety of fields. As a subfield of machine learning, deep learning offers an array of powerful algorithms for data-driven applications. Orthopaedics stands to benefit from the potential of deep learning for advancements in the field. This thesis investigated applications of deep learning for the field of orthopaedics through the development of three distinct projects.

First, algorithms were developed for the automatic segmentation of the structures in the knee from MRI. The resulting algorithms can be used to accurately segment full MRI scans in …


Pawnee Dam Inflow Design Flood (Idf) Update And Stage-Frequency Curve Development Using Rmcrfa, Jennifer P. Christensen, Joshua J. Melliger Jan 2019

Pawnee Dam Inflow Design Flood (Idf) Update And Stage-Frequency Curve Development Using Rmcrfa, Jennifer P. Christensen, Joshua J. Melliger

United States Geological Survey: Water Reports and Publications

Pawnee Dam is one of the ten Salt Creek Dams designed and built in the 1960s to mitigate flooding in Lincoln, Nebraska. This short paper illustrates the update of the Pawnee Dam inflow design flood (IDF) through calibration to recent high flow events and the development of its stage-frequency or hydrologic loading curve with the U.S. Army Corps of Engineers’ Risk Management Center Reservoir Frequency Analysis (RMC-RFA) model. The IDF update follows Engineering Regulation 1110-8-2, Inflow Design Flood for Dams and Reservoirs, including unit hydrograph peaking and two antecedent pool elevations. Background information on the original design of the dam …


Accessibility And Decay Of Web Citations In Computer Science Journals, Mohsen Jalali Jan 2019

Accessibility And Decay Of Web Citations In Computer Science Journals, Mohsen Jalali

Library Philosophy and Practice (e-journal)

The aim of this research is to scrutiny the accessibility and decay of web citations (URLs) used in refereed articles published by 27 Computer Science open access journals as indexed by Scopus. To do this, at first, we downloaded 1000 articles of Computer Science open access journals from 2009 to 2018. After acquiring articles, their web citations are extracted and analyzed from the accessibility and decay point of view. Moreover, for initially missed web citations complementary pathways such as using Google search engine are employed. Then, data collected are analyzed using descriptive statistical methods. Research findings indicated that 80.7% of …


Experimentally Linking Head Kinematics To Brain Deformation, Imouline Algharbi Jan 2019

Experimentally Linking Head Kinematics To Brain Deformation, Imouline Algharbi

Theses

Traumatic brain injury (TBI) research is used to study the effects of brain injuries and the rehabilitations for them. TBI contributes to major cause of disability and deaths quantifying up to 30% of all the head injuries. To mimic real world impact to understand the mechanism of injury head-surrogate models are used. This thesis describes a method to record head kinematics from acceleration and angular rate sensors of head-brain surrogate model for blast and blunt injury. This methodology is validated through experimental testing. To get a better insight of the head kinematics experienced by a real skull a drop tower …


Assignment Of E-Commerce Orders To Fulfillment Warehouses, Ahmad Basem Zamka Jan 2019

Assignment Of E-Commerce Orders To Fulfillment Warehouses, Ahmad Basem Zamka

Theses

For large e-commerce companies such as Amazon, when an order comes, this order might be available at more than one fulfillment centers. Therefore, the question of which fulfillment center this order should be fulfilled from would arise.

In a typical situation, customer demand is fulfilled from the closest fulfillment center. However, this approach does not always provide the optimal solution since there are so many factors that could be involved in making such a decision. These factors might include inventory balance, product correlations, and future demand.

Our decision model focuses on putting future orders in consideration while assigning orders to …


Mechanical Design Automation: A Case Study On Plastic Extrusion Die Tooling, Allen Prasad Varghese Jan 2019

Mechanical Design Automation: A Case Study On Plastic Extrusion Die Tooling, Allen Prasad Varghese

Theses

The Skills Gap in Mechanical Engineering (ME) Design has been widening with the increasing number of baby boomers retiring (Silver Tsunami) and the lack of a new generation to acquire, practice and perfect their knowledge base. This growing problem has been addressed with several initiatives focused on attracting and retaining young talent; however, these types of initiatives may not be timely for this new group to be trained by an established Subject Matter Expert (SME) group. Automated Engineering Design provides a potential pathway to address not only the Skills Gap but also the transfer of information from SMEs to a …


Recent Results From Nb₃Sn Single Cell Cavities Coated At Jefferson Lab, U. Pudasaini, M. J. Kelley, Gianluigi Ciovati, G.V. Eremeev, M. J. Kelley, C. E. Reece, Ishwari Prasad Parajuli, Md. Nizam Sayeed Jan 2019

Recent Results From Nb₃Sn Single Cell Cavities Coated At Jefferson Lab, U. Pudasaini, M. J. Kelley, Gianluigi Ciovati, G.V. Eremeev, M. J. Kelley, C. E. Reece, Ishwari Prasad Parajuli, Md. Nizam Sayeed

Physics Faculty Publications

Because of superior superconducting properties (Tc ~ 18.3K, Hs h~ 425 mT and Δ ~ 3.1 meV) compared to niobium, Nb₃Sn promise better RF performance (Q₀ and Eacc) and/or higher operating temperature (2 K Vs 4.2 K) for SRF cavities. Nb₃Sn-coated SRF cavities are produced routinely by depositing a few micron-thick Nb₃Sn films on the interior surface of Nb cavities via tin vapor diffusion technique. Early results from Nb₃Sn cavities coated with this technique exhibited precipitous low field Q-slope, also known as Wuppertal slope. Several Nb₃Sn single cell cavities coated at JLab appeared to exhibit …


Grain Yield, Crop And Basal Evapotranspiration, Production Functions And Water Productivity Response Of Drought-Tolerant And Non-Drought-Tolerant Maize Hybrids Under Different Irrigation Levels, Population Densities And Environments: Part Ii. In South-Central And Northeast Nebraska's Transition Zone And Sub-Humid Environments, Suat Irmak, Ali T. Mohammed, William Kranz Jan 2019

Grain Yield, Crop And Basal Evapotranspiration, Production Functions And Water Productivity Response Of Drought-Tolerant And Non-Drought-Tolerant Maize Hybrids Under Different Irrigation Levels, Population Densities And Environments: Part Ii. In South-Central And Northeast Nebraska's Transition Zone And Sub-Humid Environments, Suat Irmak, Ali T. Mohammed, William Kranz

Biological Systems Engineering: Papers and Publications

Information and data on newer drought-tolerant maize hybrid response to water in different climates are extremely scarce. This research quantified the performance of non-drought-tolerant (NDT) (H1) and drought-tolerant (DT) (H2, H3, and H4) maize (Zea mays L.) hybrids response to grain yield, crop evapotranspiration (ETc), basal evapotranspiration (ETb), ETc-yield production functions (ETYPF), and crop water use efficiency (CWUE) at three irrigation levels and two plant population densities (PPDs) at two locations (transition zone between sub-humid and semiarid climates at Clay Center (SCAL), Nebraska, in 2010 and 2012; and in a sub-humid climate at Concord (HAL), Nebraska, in 2010, 2011, and …


Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun Jan 2019

Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun

Biological Systems Engineering: Papers and Publications

Transplanting and fertilizer application for rice production in Bangladesh are tedious, time consuming and laborious task, and mostly done manually. Mechanical transplanting of rice becoming popular in the country in recent years and few machines have been developed for granular urea deep placement, however, having some limitations. Placing granular urea precisely along with rice transplanting, an attempt was under taken to design and fabricate an electronic control granular urea applicator to be attach with a 4-row walk behind type rice transplanter. Fabrication of the electronic granular urea applicator was done in the workshop of the Department of Farm Power and …


System And Method For Monitoring Pleural Fluid, Dimitrios Miserlis, Kim Cluff, Abby M. Kelly, Suzanne J. Higgins, Max H. Twedt Jan 2019

System And Method For Monitoring Pleural Fluid, Dimitrios Miserlis, Kim Cluff, Abby M. Kelly, Suzanne J. Higgins, Max H. Twedt

Biological Systems Engineering: Papers and Publications

The disclosure is directed to intrapleural air leak detection and monitoring. According to various embodiments of the disclosure, an air leak may be detected utilizing at least one sensor to determine whether fluid extracted from a pleural cavity of a patient includes carbon dioxide and/or a second substance. The second substance may be a foreign substance inhaled by the patient to confirm presence of the air leak. The air leak may be further monitored over a period of time by collecting temporally successive measurements associated with detected concentrations of carbon dioxide. Therefore, tissue damage and recovery may be assessed according …


Genetic Diversity And Population Structure Of A Camelina Sativa Spring Panel, Zinan Luo, Jordan Brock, John M. Dyer, Toni Kutchan, Daniel P. Schachtman, Megan Augustin, Yufeng Ge, Noah Fahlgren, Hussein Abdel-Haleem Jan 2019

Genetic Diversity And Population Structure Of A Camelina Sativa Spring Panel, Zinan Luo, Jordan Brock, John M. Dyer, Toni Kutchan, Daniel P. Schachtman, Megan Augustin, Yufeng Ge, Noah Fahlgren, Hussein Abdel-Haleem

Biological Systems Engineering: Papers and Publications

There is a need to explore renewable alternatives (e.g., biofuels) that can produce energy sources to help reduce the reliance on fossil oils. In addition, the consumption of fossil oils adversely affects the environment and human health via the generation of waste water, greenhouse gases, and waste solids. Camelina sativa, originated from southeastern Europe and southwestern Asia, is being re-embraced as an industrial oilseed crop due to its high seed oil content (36–47%) and high unsaturated fatty acid composition (>90%), which are suitable for jet fuel, biodiesel, high-value lubricants and animal feed. C. sativa’s agronomic advantages include …


Actual Evapotranspiration And Crop Coefficients Of Irrigated Lowland Rice (Oryza Sativa L.) Under Semiarid Climate, Koffi Djaman, Daran R. Rudnick, Yonnelle D. Moukoumbi, Abdoulaye Sow, Suat Irmak Jan 2019

Actual Evapotranspiration And Crop Coefficients Of Irrigated Lowland Rice (Oryza Sativa L.) Under Semiarid Climate, Koffi Djaman, Daran R. Rudnick, Yonnelle D. Moukoumbi, Abdoulaye Sow, Suat Irmak

Biological Systems Engineering: Papers and Publications

Lowland irrigated rice is the predominant crop produced in the Senegal River Valley characterized by very low annual rainfall, high temperatures, and low relative humidity. The Senegal River is shared by Senegal, Mali, Mauritania, and Guinea, and serves as the main source of irrigation water for the adopted double rice cropping system. Developing appropriate resource management strategies might be the key factor for the sustainability of rice production in the region. This study aims to estimate rice seasonal evapotranspiration (ETa), irrigation water requirement, and to develop rice growth stage specific crop coefficients (Kc) to improve rice water productivity. Field experiments …


Identifying Advantages And Disadvantages Of Variable Rate Irrigation – An Updated Review, S. A. O’Shaughnessy, Steve R. Evett, Paul D. Colaizzi, Manuel A. Andrade, Thomas H. Marek, Derek M. Heeren, Freddie R. Lamm, Jacob L. Larue Jan 2019

Identifying Advantages And Disadvantages Of Variable Rate Irrigation – An Updated Review, S. A. O’Shaughnessy, Steve R. Evett, Paul D. Colaizzi, Manuel A. Andrade, Thomas H. Marek, Derek M. Heeren, Freddie R. Lamm, Jacob L. Larue

Biological Systems Engineering: Papers and Publications

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology …


Optimization Of Process Parameters And Fermentation Strategy For Xylanase Production In A Stirred Tank Reactor Using A Mutant Aspergillus Nidulans Strain, Asmaa Abdella, Fernando Segato, Mark R. Wilkins Jan 2019

Optimization Of Process Parameters And Fermentation Strategy For Xylanase Production In A Stirred Tank Reactor Using A Mutant Aspergillus Nidulans Strain, Asmaa Abdella, Fernando Segato, Mark R. Wilkins

Biological Systems Engineering: Papers and Publications

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (kLa) for efficient xylanase production was found to be 38.6 h1. Fed batch mode and repeated batch fermentation was also performed with kLa was 38.6 h1. …


Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan Meyers, Lisa Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Millmier Schmidt Jan 2019

Antibiotic Resistance Gene Profile Changes In Cropland Soil After Manure Application And Rainfall, Morgan Meyers, Lisa Durso, John E. Gilley, Heidi Waldrip, Lana Castleberry, Amy Millmier Schmidt

Biological Systems Engineering: Papers and Publications

Land application of manure introduces gastrointestinal microbes into the environment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agricultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff. All samples were negative for the 10 b-lactamase genes assayed. For tetracycline resistance, only source …


Optimization Of Process Parameters And Fermentation Strategy For Xylanase Production In A Stirred Tank Reactor Using A Mutant Aspergillus Nidulans Strain, Asmaa Abdella, Fernando Segato, Mark R. Wilkins Jan 2019

Optimization Of Process Parameters And Fermentation Strategy For Xylanase Production In A Stirred Tank Reactor Using A Mutant Aspergillus Nidulans Strain, Asmaa Abdella, Fernando Segato, Mark R. Wilkins

Biological Systems Engineering: Papers and Publications

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (kLa) for efficient xylanase production was found to be 38.6 h-1. Fed batch mode and repeated batch fermentation was also performed with kLa was 38.6 h …


Correlations Of The Elemental Compositions Of Primary Coal Tar And Char, Andrew P. Richards, Colson Johnson, Thomas H. Fletcher Jan 2019

Correlations Of The Elemental Compositions Of Primary Coal Tar And Char, Andrew P. Richards, Colson Johnson, Thomas H. Fletcher

Faculty Publications

Simulations of large-scale coal combustors rely on accurate submodels to describe the chemical and physical changes in coal during reaction. Typically, simplified empirical submodels are tuned to experimental data to reduce the computational complexity. When data are not readily available, simplifying assumptions are used, which can create inaccuracies and biases in a large simulation. One such simplifying assumption in coal research is how to describe the elemental composition of primary pyrolysis products. This paper explores several different empirical model forms to predict the dry, ash-free fractions of C, H, O, N, and S in both the char and tar, using …