Digital Commons Network^™

Peacekeeping Operations In West Africa: Mechanisms Of Cooperation Between The United Nations And Ecowas With The Case Studies Concerning The Crises In Liberia And The Gambia, Serigne Cheikh Modou Kara Cisse

Dissertations and Theses

The African continent has significantly suffered from a great number of civil wars and armed conflicts since the beginning of the independence era in late 1960s. On May 28, 1975, the creation of a regional The African continent has significantly suffered from a great number of civil wars and armed conflicts since organization in West Africa called the Economic Community of West Africa States (ECOWAS) took place. The intent was to achieve "collective self-sufficiency" for its member states by building a full economic and trading union. In the late 1990s, the maintenance of peace and security in the region was …

Foreign Intervention And The Process Of State Failure Case Study On Libya, Islam Mohamed Goher Mohamed

Dissertations and Theses

This thesis investigates the relationship between foreign intervention and state failure. I argue that even an ideal international multilateral humanitarian intervention in a weak state will lead to deepening state failure if the intervention was biased and driven by material rather than ethical interests, focusing on achieving military victory of one party of the internal conflict rather than a negotiated settlement between all conflict parties and ignores the responsibility to rebuild in the aftermath of the intervention.

In making this argument, I developed a conceptual framework to analyse the impact of intervention motives, patterns, forms and instruments on strengthening or …

The Influence Of Size And Progression Of Intra-Cerebral Hematoma On The Lateral Ventricles, Muhammad J. Ashraf

Dissertations and Theses

Cerebrovascular diseases like intra cerebral hemorrhage are quite deadly and may disturb functioning of the brain, expanding and resulting in formation of an intra cerebral hematoma(ICH). It is imperative to comprehend how hematoma and its expansion inside the brain endangers human life. One of the influences of an ICH inside brain tissue is on the Lateral Ventricles(LV). When the hemorrhage occurs close enough to the lateral ventricles, filled with cerebrospinal fluid(CSF), it disrupts the balance of fluid in LV. A minor pressure change in LV can negatively influence the production of CSF as well as an increase in intracranial pressure. …

Diversification And Biogeography Of Pantropical Grass Yellow Butterflies (Pieridae: Coliadinae), Jing V. Leong

Dissertations and Theses

No abstract provided.

Global Food Security Under Climate-Water-Energy Nexus, Ehsan Najafi

Dissertations and Theses

During the last few decades, the global agricultural production has risen and technology enhancement is still contributing to yield growth. However, population growth, water and energy crisis, and extreme weather, climate change, etc. threaten the global food security. The focus of this study is to advance the understanding of the associations between crops productivity and large scale and local scale climatic variables, climate change, technology enhancement and assessing food-water-energy nexus to enhance global food security in a sustainable manner considering current available resources. As decision-makers try to improve food security, it is important to identify the impact of technology enhancement …

Air Ingress And Heat-Driven Flow Relaminarization In A Very High Temperature Reactor (Vhtr), Apoorva Rudra

Dissertations and Theses

Very High Temperature Reactors (VHTRs) are one of six Generation IV reactors that have been proposed for DOE’s Next Generation Nuclear Plant. In addition to using gaseous coolants, VHTRs also display benefits of passive safety systems including intra-core natural circulation for heat removal in accident scenarios. However, a number of substantial engineering challenges are expected in VHTRs, and due to the high temperatures of the coolant involved, material behavior in various components needs to be better understood. Our work focuses mainly on two key phenomena that could lead to localized hot spots in the VHTR reactor core if not addressed …

Literature Survey Of Wet-Waste And Hydrothermal Carbonization System: A Comparative Evaluation, Ramat Olaide Yusuf

Dissertations and Theses

This thesis describes the process of Hydrothermal carbonization and a comparative assessment on recent work done on the process using different feedstocks such as Raw Apple (RA), Apple chip pomace (ACP), apple juice pomace (AJP), grape pomace (GP), macadamia nut-shell (MNS), Sewage Sludge (SS), Poultry Litter (PL) and Grape Marc (GM). The data obtained from the literature survey was compared with the data obtained by the CCL team on the SWPS gasifier (HTC of poultry litter) to obtain how carbon conversion efficiency, syngas composition, thermal efficiency, char production rate, gas production rate and energy utilization vary with carbonization process conditions, …

Investigation Of The Synthesis And Optoelectronic Properties Of Ultrasmall Cdse Quantum Dots, Megan Webster

Dissertations and Theses

Traditional, or 1^st generation, solar cells have a theoretical upper limit of 33% power conversion efficiency based on the thermodynamic limitation of the single p-n junction cell design. This limitation is known as the Shockley-Queisser limit and methods to design solar cells to circumvent it have been creative, with a significant part of the field focused on quantum dot (QD) based systems. With theoretical efficiencies ranging between 44 and 67% for one sun concentration, QD solar cell designs are clearly superior to the limits of 1^st generation solar cells. However, maximum achieved efficiencies for QD-based designs are far …

Sniffing, Decoding And Decryption Of Gsm Signals Using Low Cost Hardware And Open-Source Software, Muhammad Talha Choudhry

Dissertations and Theses

We have participated in the creation of almost two terabytes of tables aimed at cracking A5/1, the most common ciphering algorithm used in GSM. Given 114-bit of known plaintext, we are able to recover the session key with a hit rate of 19%. The tables are expected to be unique as they provide the best coverage yet known to the authors and research workers and they are the first step in a real-world passive attack against GSM. An initial investigation and analysis into the air interface of GSM were performed, from both a theoretical and practical point of view. These …

Electrochemical Properties Of Crystalline Polymorphs Of Mno2 In Aluminum And Zinc Metal Batteries, Subhadip Pal

Dissertations and Theses

The widespread use of non-renewable fossil fuels has led to societal problems like global warming and climate change. Electrochemical energy storage can enable the integration of renewable energy sources that are inherently intermittent (solar, wind, etc.) into the electric grid, though major advances in cost, cycle life, and safety are necessary to have a global impact on the energy landscape. Both aluminium (Al) and zinc (Zn) metals are earth abundant, low-cost, safe, and exhibit high coulombic capacities, which make them promising electrode materials for “beyond lithium-ion” battery chemistries. However, the electrochemical feasibility and charge storage mechanisms of alternative Al and …

Heavy Truck Collision With Bridge Piers, Ran Cao

Dissertations and Theses

Based on bridge failure data compiled by the New York State Department of Transportation, collision, both caused by vessels and vehicles, is the second leading cause of bridge failures after hydraulic. The current AASHTO-LRFD (2017) specification recommends designing a bridge pier vulnerable to vehicular impacts for an equivalent static force of 2,670-kN (600 kips) applied in a horizontal plane at a distance of 1.5 m (5.0 feet) above the ground level. The vast majority of research studies on vehicular collision with bridge piers have been carried out with single-unit trucks, which are typically classified as medium-duty vehicles weighing about 89 …

Microfluidic Study Of Gravity-Driven Drainage And Coalescence Of Aqueous Two Dimensional Foams, Justin D. Heftel

Dissertations and Theses

Foams, a two-phase dispersion, are staples of the cosmetic, personal care, petroleum, pharmaceutical, and other industries. Central to these applications is the stability of the dispersion against separation. Foams break down by two mechanisms: the first is bubble coalescence, which is driven by the gravity drainage of the continuous phase. The drainage acts to push the bubbles against each other, and leads to the formation of thin lamellae, which break and cause the coalescence. The second is the mass transfer of the dispersed phase through the continuous phase, which is caused by the difference in pressures between the bubbles and …

Void Fraction Measurements In A Large (0.3 M) Diameter Bubble Column Using Wire Mesh Sensors And Pressure Transducers: Effect Of Spargers, Afolabi G. Ojo

Dissertations and Theses

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 …

Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari

Dissertations and Theses

Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH₄, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m² m^-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …

Effect Of Hypoxia On Spontaneous Neural Activity In The Cortex Of Neonate Mouse Pups, Krithikka Ravi Ms

Dissertations and Theses

Hypoxia caused by inadequate oxygenation has profound effects on the normal functioning of the brain in mammals. Acute or chronic hypoxic insults occur in the brain depending on the duration of hypoxic exposure. Hypoxia is known to occur in the human womb and exerts adverse effects on the developing fetus. Most of the ongoing research on hypoxia is performed on rodent brain slice taken from various brain regions using intracellular recording. Extensive work has been carried out to understand the effects of chronic hypoxia on the developing nervous system, specifically during intrauterine development. However, effects of acute hypoxia occurring perinatally, …

Unsupervised Feature Learning For Point Cloud By Contrasting And Clustering With Graph Convolutional Neural Network, Ling Zhang

Dissertations and Theses

Recently, deep graph neural networks (GNNs) have attracted significant attention for point cloud understanding tasks, including classification, segmentation, and detection. However, the training of such deep networks still requires a large amount of annotated data, which is both expensive and time-consuming. To alleviate the cost of collecting and annotating large-scale point cloud datasets, we propose an unsupervised learning approach to learn features from unlabeled point cloud ”3D object” dataset by using part contrasting and object clustering with GNNs. In the contrast learning step, all the samples in the 3D object dataset are cut into two parts and put into a …

Understanding And Modeling Taxi Demand Using Time Series Models, Sabiheh Faghih

Dissertations and Theses

The spatio-temporal variations in demand for transportation, particularly taxis, are impacted by various factors such as commuting, weather, road work and closures, disruption in transit services, etc. Identifying the factors that influence taxi demand and understanding its dynamic provide planners with the information necessary to improve the transportation systems and also help drivers to reduce their vacant time.

This dissertation focuses on important factors affecting the demand. In the beginning, the impact of price changes on the demand is studied. Chapter One discusses how the seasonal effects and trends are removed from the demand, and then price elasticity for demand …

Using Fundamental Properties Of Light To Investigate Photonic Effects In Condensed Matter And Biological Tissues, Laura A. Sordillo

Dissertations and Theses

Light possesses characteristics such as polarization, wavelength and coherence. The interaction of light and matter, whether in a semiconductor or in a biological sample, can reveal important information about the internal properties of a system. My thesis focuses on two areas: photocarriers in gallium arsenide and biomedical optics. Varying the excitation wavelength can be used to study both biological tissue and condensed matter. I altered the excitation wavelengths to be in the longer near-infrared (NIR) optical windows, in the shortwave infrared (SWIR) range, a wavelength region previously thought to be unusable for medical imaging. With this method, I acquired high …

Improving Retrievals Of Crop Vegetation Parameters From Remote Sensing Data, Nathaniel Levitan

Dissertations and Theses

Agricultural systems are difficult to model because crop growth is driven by the strongly nonlinear interaction of Genotype x Environment x Management (G x E x M) factors. Due to the nonlinearity in the interaction of these factors, the amount of data necessary to develop and utilize models to accurately predict the performance of agricultural systems at an operational scale is large. Satellite remote sensing provides the potential to vastly increase the amount of data available for modelling agricultural systems as a result of its high revisit time and spatial coverage. Unfortunately, there have been significant difficulties in deploying remote …

Effect Of Hypoxia On Spontaneous Neural Activity In The Cortex Of Neonate Mouse Pups, Krithikka Ravi Ms

Dissertations and Theses

Hypoxia caused by inadequate oxygenation has profound effects on the normal functioning of the brain in mammals. Acute or chronic hypoxic insults occur in the brain depending on the duration of hypoxic exposure. Hypoxia is known to occur in the human womb and exerts adverse effects on the developing fetus. Most of the ongoing research on hypoxia is performed on rodent brain slice taken from various brain regions using intracellular recording. Extensive work has been carried out to understand the effects of chronic hypoxia on the developing nervous system, specifically during intrauterine development. However, effects of acute hypoxia occurring perinatally, …

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …

Collective Behavior Of Drosophila Melanogaster Neural Progenitor And Imaginal Disc Cells Within Controlled Microenvironments, Caroline D. Pena

Dissertations and Theses

Regenerative therapies for the damaged visual system have introduced stem-derived cells to recapitulate developmental processes and initiate functional regeneration in different components of the eye. The developing visual system in Drosophila Melanogaster offers a model in which to analyze the associated processes in retinogenesis. The optic nerve is critical to vision and is developmentally preceded in Drosophila by a structure called the Optic Stalk (OS). Collective migration of neural and retinal progenitor cells (RPCs) from the developing brain lobes (DBL) to the Imaginal Disc (ID), through the OS, is a fundamental part of regenerative strategies in retina. Developmental signals governing …

Integrating Multi-Source Weather Data For Deep Learning, Haidar A. Alanbari Mr

Dissertations and Theses

Big Data has been playing a major role in the domain of Deep Learning applications as many companies and institutions continue to find solutions and extract certain trends in fields of climate change, weather forecasting and meteorology. This project extracts weather events data from multiple data sources that are supported by National Centers for Environmental information (NCEI) [1] and Amazon Web Services (AWS) [2]. Data sources include Next-Generation NEXRAD [3] Doppler radar reflectivity, GOES-16 [4] multi-channel satellite imagery and NCEI [1] storm events. Then, it integrates and refines data in proper formats to be fed to the open-source Detectron [5] …

Software Defined Radio For Hybrid Beamforming Applications, Jianyet Lee

Dissertations and Theses

Beamforming techniques have been deployed in both licensed networks such as LTE network and unlicensed network such as IEEE802.11ac WiFi. The scope of work for this thesis is to leverage the benefits of beamforming techniques and software defined radio platform in developing a fully functioning LTE testbed. The testbed can be further developed to specific application for drone-to-drone or D2D communication independent of intervention from base stations. Applying beamforming techniques to devices such as drones can solve poor quality signal detection at the receivers due to the interference signals generated by other devices in the attempt to communicate with the …

Internet Of Things: Architecture And Services For Healthcare, Ankita Suvagia Ms.

Dissertations and Theses

Internet of Things (IoT) is a recent prominent collaboration of various technologies that enables spatially distributed devices (“things”) to sense, communicate and share information, thus generating a variety of applications and services in Healthcare. IoT is implemented in multiple domains like Smart city, energy and smart grid, Smart home, weather forecasting, Agriculture, Market and Transportation, Manufacturing and testing industries, Healthcare and many more. IoT serves the purpose of making tasks more efficient and productive and at the same time ensuring quality and reliability. IoT technologies provide an enabling framework for inter-connecting devices, systems, and services that go beyond Machine-to-Machine scenarios …

Gas Hold-Up Measurements In 0.3 M Diameter Bubble Column: Effect Of Electrolytes, Heber Blanco De Brand

Dissertations and Theses

The present work reports the axial, radial and temporal gas hold-up profiles in a 0.3 m diameter batch bubble column using a pair of Wire Mesh Sensors and six pressure transducers.

A Microfluidic Tissue Array (Μfta) For Personalized Medicine Using Tumor Biopsies, A.H. R. Ahmed

Dissertations and Theses

Cancer is recognized as a complex disease with both genetic and epigenetic drivers that can vary from one individual to another. While very early research into cancer treated it as a clonal malfunction that could originate from as small as a single deregulated cell, the disease itself manifests itself with several more complexities beyond tumorigenic cells only. The tumor microenvironment itself – from the extracellular matrix to stromal cells - cooperate with tumor cells in a symbiotic manner towards metastatic progression. Clinical studies have provided more information regarding the degree of individualization possible, such that patients with similar genetic makeup …

Competition Between Veridical And Perceived Location For Visuomotor Control, Fatemeh Alhabib

Dissertations and Theses

An influential proposal holds that our visual systems use different information for perception and action. Though numerous studies utilized visual illusions, in which veridical and perceptual properties of objects differ, the evidence was inconclusive and no consensus was reached. In response priming, some evidence suggests that only physical attributes of the prime stimuli control motor responses. Across two experiments, we examined the contributions of physical and consciously perceived location to response priming, using a well-known flash-lag illusion, in which a briefly flashed disk and the moving bars appearing at the same location are perceived as displaced. In all experiments, participants …

Exploring Obesity, Adhd Severity, And Disordered Eating Behavior Among College Students, Carolina Rozario

Dissertations and Theses

Obesity is a global epidemic because of the potential health risks. There is evidence that many obese individuals manifest persistent ADHD symptoms, and that both disorders increase risk for binge eating. Nevertheless, how obesity and ADHD may increase risk for binge eating work is unclear. Neuropsychological deficits are common to all disorders and may help to explain the relations observed. The aim of this study was to explore whether neuropsychological dysfunction, especially inhibitory control weaknesses, moderate the association between greater BMI and more severe ADHD and disordered eating behaviors. Thirty-nine undergraduate college students (27 females; Mean age = 20.77, SD …

Designing An On-Demand Dynamic Crowdshipping Model And Evaluating Its Ability To Serve Local Retail Delivery In New York City, Shirin Najaf Abadi

Dissertations and Theses

Nowadays city mobility is challenging, mainly in populated metropolitan areas. Growing commute demands, increase in the number of for-hire vehicles, enormous escalation in several intra-city deliveries and limited infrastructure (road capacities), all contribute to mobility challenges. These challenges typically have significant impacts on residents’ quality-of-life particularly from an economic and environmental perspective. Decision-makers have to optimize transportation resources to minimize the system externalities (especially in large-scale metropolitan areas). This thesis focus on the intra-city mobility problems experienced by travelers (in the form of congestion and imbalance taxi resources) and businesses (in the form of last-mile delivery), while taking into consideration …