Digital Commons Network^™

Less Is More: Long-Term In Vitro Exposure To Low Levels Of Silver Nanoparticles Provides New Insights For Nanomaterial Evaluation, Kristen K. Comfort, Laura K. Braydich-Stolle, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios.

In this study, we developed and implemented a chronic in vitromodel coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated …

Remote Beehive Monitoring Using Acoustic Signals, Amro Qandour, Iftekhar Ahmad, Daryoush Habibi, Mark Leppard

Research outputs 2014 to 2021

Recent developments in Wireless Sensor Networks (WSNs) have led to their use in remote data acquisition and automatic data analysis applications, which have proven to be an invaluable tool in a diverse range of fields including biosecurity. Further indications have been found that honeybee health can be monitored and determined through the use of acoustic analysis. In this paper, we present a system that has the ability to remotely detect the presence of pest infestation on a colony of honeybees by comparing the acoustic fingerprint of a hive to a fingerprint of known status. This will aid the goals of …

Biogeochemical Controls On Biodegradation Of Mc252 Crude Oil In Coastal Wetland Systems, Matthew Paul Rodrigue

LSU Master's Theses

Weathering of MC252 oil from the Deepwater Horizon oil spill is taking place in coastal Louisiana marsh and mangrove wetland systems. Alkylated phenanthrenes and dibenzothiophenes, which are the most prominent PAHs found at MC252 contaminated sites, are weathering at rates up to 5% per year relative to alkylated chrysenes 3 years after initial oiling. Flux chambers at marsh locations trapped CO2 that exhibited δ13C signatures lower than indigenous organic matter signifying hydrocarbon mineralization to CO2. Weathering rates at each of these locations are heavily influenced by the biogeochemistry of the surrounding environment. High-resolution nutrient profiles were obtained at different locations …

Chronic Toxicity Of Nano Metallics On Red Swamp Crayfish (Procambarus Clarkii) In Laboratory And Mesocosm Studies, Jake Andrew Farlow

LSU Master's Theses

Nanotechnology has become integrated in commercial, industrial and medical products, and its use has grown exponentially in the past several years. Although potential applications of nanoparticles (NPs) are numerous, concerns about their water quality, environmental, and human health impacts remain unclear. Crayfish are ubiquitous to streams and wetland habitats, are used as a food source, and inhabit areas that could be impacted by water quality issues. Numerous studies have been conducted on the toxicity of various classes of agricultural pesticides and oils to crayfish (Procambarus clarkii) as a non-target organism. However, there is little evidence published on chronic toxicity of …

Pah Degradation In Wetland Soils As Influenced By Redox Potential, Haoxuan Zhang

LSU Master's Theses

Polycyclic aromatic hydrocarbons (PAHs) are a common contaminant in wetland soils. They are a group of compounds widely distributed in the environment and tend to accumulate in soils. Major contribution to removal of PAHs is biological degradation. For investigating the biodegradation potential of PAHs influenced by tidal actions, equipment was built for simulating the tidal actions, and concentrations of phenanthrene, pyrene, and benzo[e]pyrene were added to the soils samples which were collected from wetland. Experiments were then conducted over 120 days. Redox potentials and PAHs concentrations were measured and analyzed. Results are concluded: 1) influenced by tidal action, phenanthrene, pyrene, …

Bioavailability Of Alpha-Tocopherol Entrapped In Poly (Lactide-Co-Glycolide) (Plga) And Plga-Chitosan Nanoparticles, Lacey Caroline Simon

LSU Master's Theses

Alpha-tocopherol (áT) is a hydrophobic, antioxidant molecule shown to prevent or retard the effects of free radicals associated with diseases. It is hypothesized that the bioavailability of áT can be improved when entrapped in PLGA (Poly lactide-co-glycolide) and PLGA-Chi (PLGA-Chitosan) nanoparticles and that the mucoadhesive properties of chitosan may enhance absorption more than PLGA alone. PLGA and PLGA-Chi NPs synthesized with PVA as surfactant were characterized by measuring entrapment efficiency, size, PDI, and zeta potential when suspended in DI water. Nanoparticle physical stability was evaluated via NP exposure to environmental pH ranging from 2.5-9. Chemical stability of entrapped áT was …

Comparison Of Land Building By Mississippi River Diversion Using One And Two Dimensional Numerical Models, Gyan Prasad Basyal

LSU Master's Theses

River sediment diversions have been identified as one strategy for creating new land and offsetting Mississippi River delta plain land loss. Numerical modeling is one tool for estimating the amount of land, geomorphic features and ecological benefits from diversions. There are a number of models proposed to estimate sediment diversion land building, ranging from simplistic approaches that provide bulk characteristics and use little computational resources to process-based models that require a large amount of input parameters and computing power. This thesis aims to compare and contrast two approaches to simulating the land building processes in a simplified receiving basin: a …

Efficient Dense 3d Reconstruction Using Image Pairs, Padmapriya Ravi

LSU Master's Theses

The 3D reconstruction of a scene from 2D images is an important topic in the _x000C_eld of Computer Vision due to the high demand in various applications such as gaming, animations, face recognition, parts inspections, etc. The accuracy of a 3D reconstruction is highly dependent on the accuracy of the correspondence matching between the images. For the purpose of high accuracy of 3D reconstruction system using just two images of the scene, it is important to _x000C_nd accurate correspondence between the image pairs. In this thesis, we implement an accurate 3D reconstruction system from two images of the scene at …

Numerical Investigation Of Cryopreserved Zebrafish Sperm Cell Activation In Microchannels, Thomas Foster Scherr

LSU Doctoral Dissertations

This aim of this research project is to probe the activation process of zebrafish spermatozoa. Zebrafish are a model species for biological engineering applications, and the cryopreservation of their reproductive cells allows for inexpensive cataloging and maintenance of valuable biological material. Evaluation of cryopreservation protocols for aquatic sperm cells is typically accomplished by motility analysis after subjecting cells to a cryopreservation treatment. In zebrafish sperm cells, motility is initiated when cells come into contact with a hypo-osmotic environment. Subsequent activation analysis is currently done manually and brings with it an inherent difficulty and error. This process is slow and not …

Optimizing Bioengineered Coastal Materials, Matthew Byrum

LSU Master's Theses

Developing materials that are environmentally friendly and capable of high performance is important to maximize the efficiency and success of coastal restoration projects. Louisiana is losing large amounts of coastal land each year, while suffering 90% of the United States’ coastal wetland loss. Some areas have begun to implement physical structures to dissipate wave energy and accrete sediment. Recent technological advances have allowed the transformation of these structures into engineered ecosystems, with a focus on oyster accumulation. These ecosystems support the growth of oysters, Crassostrea virginica, which serve to improve water quality and protect shorelines through filtration and wave energy …

Development Of Remote Sensing Assisted Water Quality Nowcasting And Forecasting Models For Coastal Beaches, Zaihong Zhang

LSU Doctoral Dissertations

A remote sensing assisted water quality modeling framework is developed in this dissertation for nowcasting and forecasting recreational water quality of Holly Beach in Louisiana, USA. The modeling framework is composed of four models/systems: (1) an Artificial Neural Network (ANN) model (Model 1) and an US EPA Virtual Beach (VB) Program-based model for predicting early morning enterococci (ENT) levels in beach waters; (2) an ANN model (Model 2) and an VB model for predicting early morning Fecal Coliform (FC) levels in beach waters; (3) a remote sensing assisted modeling system (Model 3) for predicting near real time ENT levels during …

Physico-Chemical Properties Of Green Leaf Volatiles, Harsha Satyanarayana Vempati

LSU Master's Theses

Green Leaf Volatiles (GLVs) is a class of vegetation emissions whose release is greatly enhanced in the event of thermal or mechanical stress. These oxygenated hydrocarbons that have been identified as a potential source of Secondary Organic Aerosols (SOA) via aqueous oxidation. The physico-chemical properties of GLVs are vital to understanding their fate and transport in the atmosphere, but few experimental data are available. We studied the aqueous solubility, 1-Octanol/Water Partition Coefficient, and Henry’s Constant (KH) of five GLVs at 25&176;C: methyl jasmonate, methyl salicylate, 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, and cis-3-hexenyl acetate. Henry’s constant was additionally measured at 30&176;C & 35&176;C, and …

Cost And Benefit Analysis Of Shore Side Electricity In The Port Of Tanjung Perak, Indonesia, Oscar Yogi Yustiano

World Maritime University Dissertations

No abstract provided.

Microfluidic Generated Egf-Gradients Induce Chemokinesis Of Transplantable Retinal Progenitor Cells Via The Jak/Stat And Pi3kinase Signaling Pathways., Uchenna J. Unachukwu, Moira Sauane, Maribel Vazquez, Stephen Redenti

Publications and Research

A growing number of studies are evaluating retinal progenitor cell (RPC) transplantation as an approach to repair retinal degeneration and restore visual function. To advance cell-replacement strategies for a practical retinal therapy, it is important to define the molecular and biochemical mechanisms guiding RPC motility. We have analyzed RPC expression of the epidermal growth factor receptor (EGFR) and evaluated whether exposure to epidermal growth factor (EGF) can coordinate motogenic activity in vitro. Using Boyden chamber analysis as an initial high-throughput screen, we determined that RPC motility was optimally stimulated by EGF concentrations in the range of 20-400 ng/ml, with decreased …

Contrast Enhanced-Magnetic Resonance Imaging As A Surrogate To Map Verteporfin Delivery In Photodynamic Therapy, Kimberley S. Samkoe, Amber Bryant, Jason R. Gunn, Stephen P. Pereira, Tayyaba Hasan, Brian W. Pogue

Dartmouth Scholarship

The use of in vivo contrast-enhanced magnetic resonance (MR) imaging as a surrogate for photosensitizer (verteporfin) dosimetry in photodynamic therapy of pancreas cancer is demonstrated by correlating MR contrast uptake to ex vivo fluorescence images on excised tissue. An orthotopic pancreatic xenograft mouse model was used for the study. A strong correlation ([i]r=0.57 ) was found for bulk intensity measurements of T1-weighted gadolinium enhancement and verteporfin fluorescence in the tumor region of interest. The use of contrast-enhanced MR imaging shows promise as a method for treatment planning and photosensitizer dosimetry in human photodynamic therapy (PDT) of pancreas …

Beluga Whale Vocalizations, Michael T. Johnson

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

Sound files:

A Chirp; A Whistle ; B Chirp; B Whistle: Buzz; C Whistle; CH6 A Chirp; D Whistle; Down Warble; Down Whistle; E Whistle; Voca

Water Vapor Movement In Freezing Aggregate Base Materials, Maile Anne Rogers

Theses and Dissertations

The objectives of this research were to 1) measure the extent to which water vapor movement results in water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement in freezing base materials; 3) determine if the corresponding changes in water content are sufficient to cause frost heave during winter; 4) determine if the corresponding changes in water content are sufficient to cause reductions in stiffness during spring; 5) evaluate relationships between selected material properties, freezing conditions, and the occurrence and impact of water vapor movement; and 6) numerically simulate heat and water movement …

Physical Models For Simulating Ship Stability And Hydrostatic Motions, Shyh-Kuang Ueng

Journal of Marine Science and Technology–Taiwan

In this paper, efficient physics models are presented for simulating ship hydrostatic motions caused by sea waves, cargoes and flooding water. Based on the stability theory of ship, a ship is regarded as a floating body whose stability is indicated by its gravity, buoyancy and meta centers. These stability centers are influenced by cargoes, sea waves, flooding water and the ship mass. Variations of these stability centers create torques and forces which cause the ship to heave, pitch and roll. Because of the irregularity of the ship shape, analytical solutions of these stability centers do not exist. In this work, …

Integrating Information Into The Engineering Design Process, Michael Fosmire, David Radcliffe

Purdue University Press Books

Engineering design is a fundamental problem-solving model used by the discipline. Effective problem-solving requires the ability to find and incorporate quality information sources. To teach courses in this area effectively, educators need to understand the information needs of engineers and engineering students and their information gathering habits. This book provides essential guidance for engineering faculty and librarians wishing to better integrate information competencies into their curricular offerings. The treatment of the subject matter is pragmatic, accessible, and engaging. Rather than focusing on specific resources or interfaces, the book adopts a process-driven approach that outlasts changing information technologies.

After several chapters …

Computational And Experimental Study Of Degeneration, Damage And Failure In Biological Soft Tissues, Gregory Allen Von Forell

Theses and Dissertations

The purpose of this work was to analyze the biomechanics of degeneration, damage, and failure in biological soft tissues both experimentally and computationally to provide insight into tendon or ligament tearing, tendo-achilles lengthening and lumbar spine dysfunction. For soft tissue tearing, experimental studies for calculating fracture toughness were performed and determined that tendons and ligaments are able to completely resist tear propagation. For tendo-achilles lengthening, a damage model was developed to mimic the behavior of the lengthening that occurs as a result of the percutaneous triple hemisection technique. The model provided insight for predicting the amount of lengthening that occurs …

African Elephant Vocalizations, Michael T. Johnson

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

Sound files:

Croak ; Rumble ; Rev ; Snort ; Trumpet

Narrow Grass Hedge Effects On The Transport Of Antimicrobials And Antimicrobial Resistance Genes Following Land Application Of Swine Slurry, Bhavneet Soni

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The objective of this study was to determine the effects of manure amendment and narrow grass hedges on the fate and transport of antimicrobials and ARGs in runoff and in soil following the land application of swine manure slurry. Swine manure slurry was land applied to 0.75m wide by 4.0m long plots established on an Aksarben silty clay loam soil located in southeast Nebraska. The treatment factor manure amendment consisted of two levels: no manure application and manure application to meet the 3 year nitrogen (N) requirements for corn. The treatment factor of grass hedge was established for half of …

Mechanical Properties Of Hydrated Acoustically Sensitive Alginate-Based Microcapsules Confined In A Microfluidic Device As A Function Of Size And Composition, Maryam Mobed-Miremadi, Mallika Keralapura, Tiffany Fong, Rogel Camba

Bioengineering

Understanding the mechanical properties of alginate-based microcapsules according to size and chemical composition allows researchers to zero in on the treatment and methods required to engineer optimized implantable alginate-based artificial cells for chemotherapy. Cross-linked medium viscosity alginate capsules ranging from 1.1% (w/v)-1.8% (w/v) in composition and 200 μm-1200 μm in size, encapsulating ultrasound contrast agents and blue dextran were compressed within a 40 μm high polydimethylsiloxane microfluidic device and subsequently examined using 2D microscopy for strain deformation aimed at the calculation of poisson ratios and volume loss postcompression. Results indicate a decrease in Poisson ratio as a function of alginate …

On Relay Node Placement Problem For Survivable Wireless Sensor Networks, Changyong Jung

Theses and Dissertations

Wireless sensor networks are widely applied to many fields such as animal habitat monitoring, air traffic control, and health monitoring. One of the current problems with wireless sensor networks is the ability to overcome communication failures due to hardware failure, distributing sensors in an uneven geographic area, or unexpected obstacles between sensors. One common solution to overcome this problem is to place a minimum number of relay nodes among sensors so that the communication among sensors is guaranteed. This is called Relay Node Placement Problem (RNP). This problem has been proved as NP-hard for a simple connected graph. Therefore, many …

Fabrication And In Vivo Thrombogenecity Testing Of Nitric Oxide Generating Artificial Lungs, Kagya Amoako, Patrick Montoya, Terry C. Major, Ahmed B. Suhaib, Hitesh Handa, David O. Brant, Mark E. Meyerhoff, Robert H. Bartlett, Keith E. Cook

Mechanical and Industrial Engineering Faculty Publications

Hollow fiber artificial lungs are increasingly being used for long-term applications. However, clot formation limits their use to 1–2 weeks. This study investigated the effect of nitric oxide generating (NOgen) hollow fibers on artificial lung thrombogenicity. Silicone hollow fibers were fabricated to incorporate 50 nm copper particles as a catalyst for NO generation from the blood. Fibers with and without (control) these particles were incorporated into artificial lungs with a 0.1 m2 surface area and inserted in circuits coated tip-to-tip with the NOgen material. Circuits (N = 5/each) were attached to rabbits in a pumpless, arterio-venous configuration and run for …

Layered Long Term Co-Culture Of Hepatocytes And Endothelial Cells On A Transwell Membrane: Toward Engineering The Liver Sinusoid, Young Bok (Abraham) Kang, Siddhartha Rawat, Joseph Cirillo, Michael Bouchard, Hongseok (Moses) Noh

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin matrigel layer placed between hepatocytes and endothelial cells to mimic the Space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs …

Ole Miss Engineer 2013-2014

Ole Miss Engineer

No abstract provided.

Improvement Of Pedagogical Laboratory Based Learning: Multimedia Enhanced Instructional Methods, Sumbul Khan

Masters Theses & Specialist Projects

In engineering technology and other scientific-based education, lab-based courses play a crucial role (Ma & Nickerson, 2006). Even though laboratory experience in student learning is crucial, it faces some problems. Due to insufficient laboratory conditions that lead to overcrowding and inability to view demonstrations, the effectiveness of hands on experience declines (Tiwari & Singh, 2011; Tuysuz, 2010). Considering the limitations that constrain lab experience, investigating and implementing alternatives to enhance pedagogical laboratory based learning becomes inevitable. This study investigates multimedia enhanced pedagogical teaching methods for delivering laboratory instruction to students. The purpose of this study was to improve pedagogical laboratory …

Friction And Wear Of Polytetrafluoroethylene/Graphene Oxide Composite Thin Films, Justin Kyle Carter

Graduate Theses and Dissertations

Polytetrafluoroethylene (PTFE) is a commonly used solid lubricant due to its low coefficient of friction and chemical inertness. As a polymer, PTFE suffers from high wear and low adhesion to substrates limiting its use as a thin film. Thin PTFE films are ideal candidates for solid lubrication in micro-machines and bearing applications. The main goal of this work is to enhance the durability of thin PTFE films through the addition of few layered graphene oxide (GO) as filler. In order to address adhesion issues, the addition of an adhesive layer of polydopamine (PDA) between stainless steel substrates and thin PTFE …

Face Recognition Using Statistical Adapted Local Binary Patterns., Abdallah Abd-Elghafar Mohamed

Electronic Theses and Dissertations

Biometrics is the study of methods of recognizing humans based on their behavioral and physical characteristics or traits. Face recognition is one of the biometric modalities that received a great amount of attention from many researchers during the past few decades because of its potential applications in a variety of security domains. Face recognition however is not only concerned with recognizing human faces, but also with recognizing faces of non-biological entities or avatars. Fortunately, the need for secure and affordable virtual worlds is attracting the attention of many researchers who seek to find fast, automatic and reliable ways to identify …