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

Engineering Commons

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

City University of New York (CUNY)

Dissertations and Theses

Articles 1 - 30 of 98

Full-Text Articles in Engineering

The Influence Of Size And Progression Of Intra-Cerebral Hematoma On The Lateral Ventricles, Muhammad J. Ashraf Jan 2019

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 ...


Designing An On-Demand Dynamic Crowdshipping Model And Evaluating Its Ability To Serve Local Retail Delivery In New York City, Shirin Najaf Abadi Jan 2019

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 ...


Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan Jan 2019

Modification Of Lipid Microenvironments On Solid Support Structures For Use In Transmembrane Protein Assays, William J. Houlihan

Dissertations and Theses

Gamma-Secretase (γ-secretase) is a transmembrane protease of increasing interest, which has been shown to have significant connections to both cancer and Alzheimer’s disease. γ-secretase cleaves both Notch-1, a transmembrane signaling protein, and Amyloid precursor protein (APP), a transmembrane protein whose cleavage may result in the formation of β-amyloid plaques in the brain. Notch-1 and APP are widely studied proteins that have substantial impacts on the development and proliferation of cancer and Alzheimer’s disease, respectively. Notch-1 partakes in the signaling of apoptosis in damaged and mutated cells, thus its cleavage by γ-secretase within the plasma membrane has ramifications on ...


Neuron-Glial (Ng) Interactions: A Microfluidic Examination Of Ng Emergent Responses For Repair, Tanya Singh Jan 2019

Neuron-Glial (Ng) Interactions: A Microfluidic Examination Of Ng Emergent Responses For Repair, Tanya Singh

Dissertations and Theses

Neuron-glia communication is crucial to the development, plasticity, and repair of the nervous system (NS). While neurons are well known to conduct electrical impulses that transfer biological information and stimuli throughout the NS, our understanding of the roles of glia continues to evolve from when the cells were largely believed to act solely for neuronal support. Recent decades of research has shown that glia can alter metabolism, conduct impulses and change phenotype for NS repair. NG interactions have, thereby, become heavily researched in varied areas of biomedical engineering, including embryogenesis, neural regeneration, growth, and intracellular synaptic activity. However, while NG ...


Controlled Migration Of Retinal Progenitor Cells Within Electro-Chemotactic Fields, Shawn Mishra Jan 2019

Controlled Migration Of Retinal Progenitor Cells Within Electro-Chemotactic Fields, Shawn Mishra

Dissertations and Theses

Vision loss in retinal degenerative diseases is overwhelmingly attributed to damage and death of retinal photoreceptor cells. Studies in mouse retina have suggested that transplantation of isolated post-natal or stem cell-derived retinal progenitor cells (RPCs) to replace apoptotic or damaged photoreceptors may be a novel approach to restore vision. Thus far, outcomes project that the amount of restored visual response depends upon the migration of transplanted cells from insertion in the sub-retinal space to the outer nuclear layer (ONL). However, transplantation efficiency is exceedingly low – ~5% cells transplanted enter the retina – directly limiting the efficacy of the treatments. Additionally, the ...


Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong Jan 2019

Translational Modeling Of Non-Invasive Electrical Stimulation, Dennis Quangvinh Truong

Dissertations and Theses

Seminal work in the early 2000’s demonstrated the effect of low amplitude non-invasive electrical stimulation in people using neurophysiological measures (motor evoked potentials, MEPs). Clinical applications of transcranial Direct Current Stimulation (tDCS) have since proliferated, though the mechanisms are not fully understood. Efforts to refine the technique to improve results are on-going as are mechanistic studies both in vivo and in vitro. Volume conduction models are being applied to these areas of research, especially in the design and analysis of clinical montages. However, additional research on the parameterization of models remains.

In this dissertation, Finite Element Method (FEM) models ...


Ict-Enabled Control And Energy Management Of Community Microgrids For Resilient Smart Grid Operation, Mahmoud Saleh Jan 2019

Ict-Enabled Control And Energy Management Of Community Microgrids For Resilient Smart Grid Operation, Mahmoud Saleh

Dissertations and Theses

Our research has focused on developing novel controllers and algorithms to enhance the resilience of the power grid and increase its readiness level against major disturbances.

The U.S. power grid currently encounters two main challenges: (1) the massive and extended blackouts caused by natural disasters, such as hurricane Sandy. These blackouts have raised a national call to explore innovative approaches for enhanced grid resiliency. Scrutinizing how previous blackouts initiated and propagated throughout the power grid, the major reasons are lack of situational awareness, lack of real-time monitoring and control, underdeveloped controllers at both the transmission and distribution levels, and ...


Multi-Scale Assessment Of Bone Mechanics And The Mineral Phase Of Intramuscular Bone Of Atlantic Herring Fish, Svetlana Zeveleva Jan 2017

Multi-Scale Assessment Of Bone Mechanics And The Mineral Phase Of Intramuscular Bone Of Atlantic Herring Fish, Svetlana Zeveleva

Dissertations and Theses

Bone tissue is a complex composite structure made up of a soft organic phase consisting of collagen I and non-collagenous proteins, and a hard inorganic phase consisting of mineral nanoplatelets. Given it’s compositional properties, bone is a unique stiff, tough, and strong biomaterial, making it exceptionally difficult to synthesize ex vivo. While the complete hierarchical structure may change with age and population, the basic building block components of mineralized collagen fibrils, are preserved. This study uses a model of intramuscular bone of the Atlantic herring fish, which present a simple structure, and no process of remodeling.

A multi-scale approach ...


Understanding Adversarial Training: Improve Image Recognition Accuracy Of Convolution Neural Network, Naoki Ishibashi Jan 2017

Understanding Adversarial Training: Improve Image Recognition Accuracy Of Convolution Neural Network, Naoki Ishibashi

Dissertations and Theses

Traditional methods of computer vision and machine learning cannot match human performance on tasks such as the recognition of handwritten digits. Recently many researchers work on Convolution Neural Network for image recognition, and get results as good as human being. Additionally, Image recognition task is getting more popular and high demand to apply to other fields, but also there are still many problems to utilize in everyday life. One of these problems is that several machine learning models, including neural networks, consistently misclassify adversarial examples—inputs formed by applying small but intentionally worst-case perturbations to examples from the dataset, such ...


2d Vector Map And Database Design For Indoor Assisted Navigation, Luciano Caraciolo Albuquerque Jan 2017

2d Vector Map And Database Design For Indoor Assisted Navigation, Luciano Caraciolo Albuquerque

Dissertations and Theses

In this paper we implemented a 2D Vector Map, map editor and Database design intended to provide an efficient way to convert cad files from indoor environments to a set of vectors representing hallways, doors, exits, elevators, and other entities embedded in a floor plan, and save them in a database for use by other applications, such as assisted navigation for blind people.

A graphical application as developed in C++ to allow the user to input a CAD DXF file, process the file to automatically obtain nodes and edges, and save the nodes and edges to a database for posterior ...


Influence Of Fibroblasts On Metastatic Cancer Cell Drug Resistance In A 3d Microfluidic Cell Array, Elizabeth C. Benoy Jan 2017

Influence Of Fibroblasts On Metastatic Cancer Cell Drug Resistance In A 3d Microfluidic Cell Array, Elizabeth C. Benoy

Dissertations and Theses

Modeling an accurate depiction of the tumor microenvironment, (TME), is essential to observe the effect external factors might have on the tumor in vivo. In cancer therapy specifically, the outcomes of clinical treatments are heavily dependent on drug testing methods despite the cytotoxic effects these methods might have on the patient. Our lab has previously developed a three layered microfluidic cell array (3D μFCA) to reconstruct the relevantly spatial configuration of tumor and microvasculature found in vivo in order to develop a more efficient tool of high throughput drug discovery and screening. In this study, we optimized this device to ...


Design Development And Performance Study Of A Novel Assistive Device For Mobility Of Toddlers And Children With Visual Impairments, Joowon Jun Jan 2017

Design Development And Performance Study Of A Novel Assistive Device For Mobility Of Toddlers And Children With Visual Impairments, Joowon Jun

Dissertations and Theses

Being able to see allows mankind tremendous access to learn about the world, and because so much learning comes visually, children with visual impairments are delayed in developing range of skills: learning own languages, doing activities, socializing with peers, and etc. While children with vision can do virtually all the activities and tasks for granted, children with visual impairment require different types of tools or materials to do same tasks most of time. Amongst all the disadvantages that children with visual impairment have, one of the most critical disadvantageous area that visual impairment brings to toddler is learning to walk ...


Ionic Liquids Tethered To Activated Carbon For Capture Of Airborne Toxins, Devin Peck Jan 2017

Ionic Liquids Tethered To Activated Carbon For Capture Of Airborne Toxins, Devin Peck

Dissertations and Theses

Ionic liquids (ILs) were investigated for functionalization of activated carbon (AC) adsorbents for the filtration of warfare toxins. Preliminary steps were taken by testing absorption capacity of neat ILs and tethering ionic liquids to the surface of AC. AC is known to have good adsorption ability for warfare agents. Functionalizing the AC with ILs could enhance the capture ability significantly. ILs have been found to be good absorbents for a variety of gaseous species. The absorption selectivity and capacity can be tuned by changing the anion-cation pair. By tethering ILs to AC, the beneficial properties of gas absorption from ILs ...


Automatic Optimum Atlas Selection For Multi-Atlas Image Segmentation Using Joint Label Fusion, Kofi Agyeman Jan 2017

Automatic Optimum Atlas Selection For Multi-Atlas Image Segmentation Using Joint Label Fusion, Kofi Agyeman

Dissertations and Theses

Multi-atlas image segmentation using label fusion is one of the most accurate state of the art image segmentation techniques available for biomedical imaging applications. Motivated to achieve higher image segmentation accuracy, reduce computational costs and a continuously increasing atlas data size, a robust framework for optimum selection of atlases for label fusion is vital. Although believed not to be critical for weighted label fusion techniques by some works (Sabuncu, M. R. et al., 2010, [1]), others have shown that appropriate atlas selection has several merits and can improve multi-atlas image segmentation accuracy (Aljabar et al., 2009, [2], Van de Velde ...


Data Driven Approach For Increasing Power Grid Situational Awareness And Mitigating Cascaded Failures, Yassine Mhandi Jan 2017

Data Driven Approach For Increasing Power Grid Situational Awareness And Mitigating Cascaded Failures, Yassine Mhandi

Dissertations and Theses

The main purpose of this thesis is to use Artificial Neural network as a tool to monitor system health and performance. In other word Using ANN can increase the system awareness and can be used as a tool to mitigate cascade failure in power grid due to loss of communication in a critical power node and as a result avoid catastrophic phenomena like electric blackout. In this thesis, a modified IEEE 30 bus system is used as a system under study. Modified IEE 30 bus system is IEEE 30 bus system in which 2 sets of its synchronous condensers changed ...


A Hybrid State/Event Driven Communication-Based Control For Dc Microgrids, Yusef Esa Jan 2017

A Hybrid State/Event Driven Communication-Based Control For Dc Microgrids, Yusef Esa

Dissertations and Theses

The U.S. electric power industry is undergoing unprecedented changes triggered by the growing electricity demand, and the national efforts to reduce greenhouse gas emissions. Moreover, there is a call for increased power grid resiliency, survivability and self-healing capabilities. As a result of these challenges, the smart grid concept emerged. One of the main pillars of the smart grid is microgrids. In this thesis, the technical merits of clustering multiple microgrids during blackouts on the overall stability and supply availability have been investigated.

We propose to use the existing underground distribution grid infrastructure, if applicable, during blackouts to form microgrid ...


A New Thin Layered Structural Coating On A Metal Substrate For Enhanced Hydrogen Production From Steam Methane Reforming, Michael A. Lugo-Pimentel Jan 2017

A New Thin Layered Structural Coating On A Metal Substrate For Enhanced Hydrogen Production From Steam Methane Reforming, Michael A. Lugo-Pimentel

Dissertations and Theses

In the past decade the use of hydrogen has become more ubiquitous. Its applications range from the upgrading of fossil fuels, to the production of ammonia, to the hydrogenation of fats, to the production of muriatic acid and methanol, all without including the efforts being taken to move towards a hydrogen economy. Its widespread use and its increasing demand lays pressure to find more efficient techniques of hydrogen production. Because the overwhelming majority of hydrogen produced nowadays comes from the steam reforming of natural gas (SMR), it appears that the most adept way to improve yields is by improving the ...


The Political Water Web Of The United States, Omar Hammad Jan 2017

The Political Water Web Of The United States, Omar Hammad

Dissertations and Theses

The United States’ water systems are interstate in their nature; these systems are governed by Congressional compact agreements. Water compacts have been influenced by common factors that have reverberated throughout the water-web of the country. These impacts varied in their scale, national level federal regulations, such as the Endangered Species Act of 1973, and recent concerns about climate change are macro-scale influences. Localized drivers such as regional economics and population change are localized impacts. While these concepts and issues influence water compacts as a whole, their impacts occur at different periods, albeit for the same reason. As such, we see ...


Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park Jan 2017

Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park

Dissertations and Theses

Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose ...


Property Analysis Of Silylamine Type Reversible Ionic Liquids For Use As A Thermal Safety Switch In Batteries, Showmik Podder Jan 2017

Property Analysis Of Silylamine Type Reversible Ionic Liquids For Use As A Thermal Safety Switch In Batteries, Showmik Podder

Dissertations and Theses

The increased capacity of the modern battery system has also brought about safety apprehensions. Uncontrollable runaway reactions are a big concern in these systems; these reactions are the result of in situ heat generation and very much increase the risk of explosions and device failures. The concept of this work is to provide a preliminary understanding into the use of a type of switchable solvent known as reversible ionic liquids (RevILs) and their feasibility in being used in electrolytes as a thermally-controlled reversible safety switch. In their pure forms these switchable solvents experience a dramatic change in their properties upon ...


Brief Study Of Classification Algorithms In Machine Learning, Ramesh Sankara Subbu Jan 2017

Brief Study Of Classification Algorithms In Machine Learning, Ramesh Sankara Subbu

Dissertations and Theses

The purpose of this study is to briefly learn the theory and implementation of three most commonly used Machine Learning algorithms: k-Nearest Neighbors (kNN), Decision Trees and Naïve Bayes. All these algorithms fall under the Classification algorithm category of Unsupervised Machine Learning. This paper is constructed structurally in explaining the working theory behind each algorithm and an implementation of a Machine Learning problem solved by each algorithm. KNN algorithm is designed using Euclidean distance measurement and Decision Trees make use of ID3 algorithm as a basis. We conclude the study by providing an overall picture of its strengths and weaknesses ...


Innovative System For Seismic Control Strategies, Seyed Ali Razavi Jan 2016

Innovative System For Seismic Control Strategies, Seyed Ali Razavi

Dissertations and Theses

Among various alternative approaches, installing auxiliary damping devices such as tuned mass dampers (TMDs) is a very reliable solution to mitigate wind-induced vibration of tall buildings. However, regardless of the different distribution strategies, installing TMD systems means adding additional masses to tall buildings. A valuable space on top of tall buildings is sacrificed to contain a large bulky mass, which is not aesthetically pleasing. Furthermore, increasing the mass of tall buildings by installing extra mass systems is not time and cost effective process. In order to address the issues, this paper investigates the utilization of feasible alternative for the purpose ...


Mechanistic-Empirical Pavement Design Guide (Mepdg) Method Implemented To Estimate Damage In Flexible And Rigid Pavements, Tenzin Gusto Jan 2016

Mechanistic-Empirical Pavement Design Guide (Mepdg) Method Implemented To Estimate Damage In Flexible And Rigid Pavements, Tenzin Gusto

Dissertations and Theses

The implementation of the Empirical-Mechanistic Pavement Design Guide (MEPDG) method for flexible and rigid pavements requires numerous input parameters. Most of these parameters can be easily determined while some require best estimates that are usually extracted from available literature. This thesis identifies the most critical input parameters in terms of their effects on the damage of pavements and their influence on the determination of the number of corrective maintenance cycles to be performed during the design life of pavements. It was found that for flexible pavement, change in the average monthly temperature by as little as results in large differences ...


Discrete Model For Cancer Tumor Growth And Effect Of Chemotherapy, Karim Virani Jan 2016

Discrete Model For Cancer Tumor Growth And Effect Of Chemotherapy, Karim Virani

Dissertations and Theses

Many mathematical models have focused on growth of a single tumor with their spreading rate with some have included its metastasis. Some of the earlier models focus on exponential growth and its shift with time on to a linear model. The Gompertzian model involves a quadratic terms and that limit growth. We looked into Iwata et al paper it discusses a different model and takes into account the growth and metastasis of a tumor population but does not look into tumor shrinking or chemotherapy. Our new model focuses on the extending Iwata et al model to take into account tumor ...


Direct Current Stimulation Modulates Ltp And Ltd: Activity-Dependence And Dendritic Effects, Gregory Kronberg Jan 2016

Direct Current Stimulation Modulates Ltp And Ltd: Activity-Dependence And Dendritic Effects, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) has been reported to improve various forms of learning in humans. Stimulation is often applied during training, producing lasting enhancements that are specific to the learned task. These learning effects are thought be mediated by altered synaptic plasticity. However, the effects of DCS during the induction of endogenous synaptic plasticity remain largely unexplored. To model endogenous plasticity I induced long-term potentiation (LTP) and depression (LTD) at Schaffer collateral synapses in CA1 of rat hippocampal slices. When induction was paired with concurrent DCS, the resulting plasticity was biased towards potentiation, such that LTP was enhanced and ...


Ultrahigh Field Magnetic Resonance Imaging – Technical Development And Translational Applications, Judy Alper Jan 2016

Ultrahigh Field Magnetic Resonance Imaging – Technical Development And Translational Applications, Judy Alper

Dissertations and Theses

Magnetic resonance imaging (MRI) may be used to provide detailed images of the human body with excellent soft tissue contrast. Alongside its current widespread clinical applications for diagnosis and treatment, MRI allows researchers to measure structure and function of different tissue types in order to advance our understanding of human biology and enable new medical applications of MRI. In particular, diseases affecting nerves and vessels, such as trigeminal neuralgia, with uncertain etiology can be studied using multiple MRI modalities so that treatment planning can we more effective and patient outcomes can be improved. Ultrahigh field MRI scanners, such as those ...


Chemotaxis Of Central Nervous System-Derived Tumor Cells Within Controlled Microenvironments, Jennifer Rico Varela Jan 2015

Chemotaxis Of Central Nervous System-Derived Tumor Cells Within Controlled Microenvironments, Jennifer Rico Varela

Dissertations and Theses

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cell-derived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient- dependence of motile cells. Data ...


Development Of Super Hydrophobic Surfaces Using Silica Nanoparticles, Muhammad Salman Saleem Jan 2015

Development Of Super Hydrophobic Surfaces Using Silica Nanoparticles, Muhammad Salman Saleem

Dissertations and Theses

The development of surfaces that have high water contact angles and hysteresis has always been of great importance in industrial applications. Various methods and techniques have been introduced to fabricate surfaces at nano-scale to support super hydrophobicity. Some of these techniques are expensive, some are very complex, most can be used for selective materials and substrate and some form surfaces with very poor wear resistance. This document represents a systematic study on fabrication of super hydrophobic surfaces on glass substrate (SiO2) using the functionalized silica (SiO2) nano particles. SU8, Polydimethylsiloxane (PDMS) and Methyphenyl Resin SR355 polymer are being used as ...


Exploration Of The Mechanical Properties Of Both Ridged And Inflated Drop Stitch Fabric Material, Roberto Felicissimo Jan 2015

Exploration Of The Mechanical Properties Of Both Ridged And Inflated Drop Stitch Fabric Material, Roberto Felicissimo

Dissertations and Theses

The mechanical properties of drop stitch fabric materials in tension and shear has been investigated for use in designing structural applications such as ship construction, modular buildings, inflatable structures, aquatic vehicles, sporting goods and temporary field equipment installations. The goal of testing is to improve the understanding of the mechanical properties, which can aid in application development for structural deployments using these unique materials. The benefits of using rigid drop stitch fabric panels in ship and building construction are their light weight and rigidity. The epoxy resin infused fabric is corrosion and degradation resistant while providing a more robust resistance ...


An Experimental Study Of Subcooled Flow Boiling At Elevated Pressure In An Annular Flow Channel, Pervej Rahman Jan 2015

An Experimental Study Of Subcooled Flow Boiling At Elevated Pressure In An Annular Flow Channel, Pervej Rahman

Dissertations and Theses

An experimental setup was developed to study the region of subcooled flow boiling. Multiple studies were carried out to investigate the effects of liquid velocity, pressure, and temperature on the boiling heat transfer of subcooled fluid flowing through a heated annular channel. Water was used as the working fluid and principle of Ohmic heating was used to raise water temperature. The system pressure, heat flux, & mass flux ranged from 101 to 912 kPa, 19 to 155 kW/m2, and 83 to 332 kg/m2-s, respectively. This report contains boiling curves, heat transfer coefficients of various studies and a description of ...