Engineering Commons^™

Enabling Method To Design Versatile Biomaterial Systems From Colloidal Building Blocks, Shalini Saxena, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Development of materials with fine spatial control over topographical, mechanical, or chemical features has been investigated for a variety of applications. Here we present a method to fabricate an array of polyelectrolyte constructs including two-dimensionally and three-dimensionally patterned assemblies using both compressible and incompressible colloidal building blocks. This method eliminates prior constraints associated with specific chemistries, and can be used to develop modular, multi-component, patterned assemblies. In particular, development of constructs were investigated using microgels, which are colloidally stable hydrogel microparticles, polystyrene (PS) beads, and PS-microgel core-shell building blocks in conjunction with the polycation poly(ethyleneimine) (PEI). The topography, mechanical properties, …

Spectrum Of Intracerebral Hemorrhage In Children: A Report From Picu Of A Resource Limited Country, Qalab Abbas, Qurat Ul Ain Merchant, Bushra Nasir, Anwar Ul Haque, Basit Salam, Gohar Javed

Department of Paediatrics and Child Health

Intracerebral hemorrhage (ICH) in children is a rare but disabling disease that accounts for almost half cases of stroke. We report our experience of ICH in children. Retrospective review of medical records of children (1 month-16 years) admitted in Pediatric Intensive Care Unit between January 2007 and December 2014 was done. Data collected included age, gender, presentation, examination findings, neuroimaging done (CT, MRI, and angiography) management (conservative/intervention), and outcome. Results are presented as frequency and percentages. Of the total 50 patients, 58% were male and 26% were <1 year. On presentation 44% had vomiting, 42% had seizures, and GCS < 8 while 40% had altered level of consciousness. Single bleed was present in 88%, 94% had supratentorial bleed, and 32% had intraventricular extension. 72% had bleed volume of <30 mL and 8% had >60 mL. CT scan was done in 98% patients and MRI in 34%, …

Geometric Deformations Of Sodalite Frameworks, Ciprian Borcea, Ileana Streinu

Computer Science: Faculty Publications

In mathematical crystallography and computational materials science, it is important to infer flexibility properties of framework materials from their geometric representation. We study combinatorial, geometric and kinematic properties for frameworks modeled on sodalite.

Exploring Maintenance And Facility Operations Strategies For California Community Colleges, Virginia Parras Grande

Walden Dissertations and Doctoral Studies

California community college leaders are looking for strategies to sustain facilities and maintenance operations because the governor only approved the allocation of $87.5 million in the 2014-2015 Budget Act for facilities maintenance operations. Guided by the change and strategy theories, the purpose of this multicase study was to explore the strategies that a select group of college leaders have used to sustain or improve their facilities maintenance operations. The data collection process included a review of college planning documents and semistructured interviews with 10 senior administrators from 3 large California community colleges who have used strategies to address sustaining or …

Decision Making Of Environmental Engineers On Project Selection, Millicent Amanda Davis

Walden Dissertations and Doctoral Studies

Some environmental engineers do not understand how to perceive profitable opportunities in redeveloping the large number of contaminated brownfield sites in New Jersey. The purpose of this qualitative exploratory case study was to find effective decision-making strategies that help environmental engineers acquire profitable environmental redevelopment projects. The target population consisted of 4 environmental engineers in an environmental organization in Camden County, New Jersey who possessed proven decision-making strategies that helped them acquire profitable environmental redevelopment projects in the past 5 years. The conceptual framework for this study was the multiple criteria decision method (MCDM). Semistructured interviews were conducted with the …

An Analysis Of The Technological, Organizational, And Environmental Factors Influencing Cloud Adoption, Joe Malak

Walden Dissertations and Doctoral Studies

Cloud computing provides an answer to the increasing costs of managing information technology (IT), and has become a model that aligns IT services with an organization's business strategies. However, concerns and uncertainties associated with cloud computing are deterring IT decision makers from making sound decisions regarding the adoption of the technology. The purpose of this online survey study was to examine the relationship between relative advantage, compatibility, organizational size, top management support, organizational readiness, mimetic pressure, normative pressures, coercive pressure, and the IT decision makers' intent to adopt cloud computing. The theoretical framework incorporated the diffusion of innovations theory, a …

Investing In Least Developed Countries: The Aynak Copper Mine Project, Roosevelt Barfield

Walden Dissertations and Doctoral Studies

The rise of market globalization creates challenges for business executives seeking to pursue foreign direct investment (FDI) in least developed countries (LDC), such as Afghanistan. Multinational corporate (MNC) executives need strategies that will improve the timely delivery of minerals for mining projects in LDCs. Guided by the force field analysis theory, the purpose of this holistic, single-case study was to explore the strategy that 5 MNC executives in Beijing, China, used to improve the timely delivery of minerals associated with the Aynak copper mine project in Afghanistan. Semistructured interviews were used to elicit detailed narratives from MNC executives about their …

Strategies To Improve Data Quality For Forecasting Repairable Spare Parts, Uyi Harrison Eguasa

Walden Dissertations and Doctoral Studies

Poor input data quality used in repairable spare parts forecasting by aerospace small and midsize enterprises (SME) suppliers results in poor inventory practices that manifest into higher costs and critical supply shortage risks. Guided by the data quality management (DQM) theory as the conceptual framework, the purpose of this exploratory multiple case study was to identify the key strategies that the aerospace SME repairable spares suppliers use to maximize their input data quality used in forecasting repairable spare parts. The multiple case study comprised of a census sample of 6 forecasting business leaders from aerospace SME repairable spares suppliers located …

Building Designers' Perception And The Effect On Sustainability In Malawi, Lloyd Ndau

Walden Dissertations and Doctoral Studies

Environmental sustainability in buildings is an important part of preserving the environment and reducing climate change. The increasing amount of physical infrastructure systems in Malawi has not been accompanied by policy-makers clearly understanding perceptions and attitudinal behaviors of building designers to promote environmental sustainability. Some building designers in Malawi might not be practicing sustainability innovations adequately, requiring more research to understand their perceptions and behaviors. The purpose of this mixed methods sequential and explanatory study was to explore how building designers' behaviors relate to the implementation of sustainability innovations in Malawi. Ajzen's theory of planned behavior explaining how attitudinal behaviors …

An Evaluation Of Robotics In Nursing Homes To Reduce Adverse Drug Events, Ozell Ueal Jr.

Walden Dissertations and Doctoral Studies

Adverse drug events (ADE) cause many deaths annually in addition to affecting the quality of life of many others. The descriptive mixed methods approach, specifically exploratory case study and experimental design that guided this research utilized the survey and focus group methods to evaluate perceptions about robotic technology (RT) to reduce the rate of ADEs in U.S. nursing homes (NH). There is a lack of scholarly research into whether a conceptual approach rooted in RT can be implemented to assist with drug administrations in NHs. The purpose of this study was twofold. The first purpose was to evaluate the causes …

The Next Billion: Lessons In Off-Grid Electricity Development From The Global South, Peter Mcdonough

Graduate Student Theses, Dissertations, & Professional Papers

Today about a third of the world’s population has no access to electricity, and another third has only limited access. Driven by the push for development on one hand and the reality of climate change on the other, a combination of for-profit companies, NGOs, missions, and aid organizations is looking for the silver bullet to sustainable electricity development. In order to understand the challenges facing off-grid electricity projects I used recent literature in the form of peer-reviewed journals, agency reports, news articles, and technical documents; stakeholder interviews; and on-site observations in selected case studies in Nepal, India, and Tanzania. In …

Applying Dijkstra Algorithm For Solving Neutrosophic Shortest Path Problem, Florentin Smarandache, Luige Vladareanu, Said Broumi, Assia Bakali, Muhammad Akram

Branch Mathematics and Statistics Faculty and Staff Publications

The selection of shortest path problem is one the classic problems in graph theory. In literature, many algorithms have been developed to provide a solution for shortest path problem in a network. One of common algorithms in solving shortest path problem is Dijkstra’s algorithm. In this paper, Dijkstra’s algorithm has been redesigned to handle the case in which most of parameters of a network are uncertain and given in terms of neutrosophic numbers. Finally, a numerical example is given to explain the proposed algorithm.

Salient Pairwise Spatio-Temporal Interest Points For Real-Time Activity Recognition, Mengyuan Liu, Hong Liu, Qianru Sun, Tianwei Zhang, Runwei Ding

Research Collection School Of Computing and Information Systems

Real-time Human action classification in complex scenes has applications in various domains such as visual surveillance, video retrieval and human robot interaction. While, the task is challenging due to computation efficiency, cluttered backgrounds and intro-variability among same type of actions. Spatio-temporal interest point (STIP) based methods have shown promising results to tackle human action classification in complex scenes efficiently. However, the state-of-the-art works typically utilize bag-of-visual words (BoVW) model which only focuses on the word distribution of STIPs and ignore the distinctive character of word structure. In this paper, the distribution of STIPs is organized into a salient directed graph, …

We Can Hear You With Wi-Fi!, Guanhua Wang, Yongpan Zou, Zimu Zhou, Kaishun Wu, Lionel M. Ni

Research Collection School Of Computing and Information Systems

Recent literature advances Wi-Fi signals to “see” people’s motions and locations. This paper asks the following question: Can Wi-Fi “hear” our talks? We present WiHear, which enables Wi-Fi signals to “hear” our talks without deploying any devices. To achieve this, WiHear needs to detect and analyze fine-grained radio reflections from mouth movements. WiHear solves this micro-movement detection problem by introducing Mouth Motion Profile that leverages partial multipath effects and wavelet packet transformation. Since Wi-Fi signals do not require line-of-sight, WiHear can “hear” people talks within the radio range. Further, WiHear can simultaneously “hear” multiple people’s talks leveraging MIMO technology. We …

Proactive Strategies In Personal Dose Monitoring, Prevention And Mitigation, Manish Kumar Sharma

Doctoral Dissertations

"At certain threshold, nuclear radiation (like x-rays and gamma-rays) may adversely impact the health of living tissues. The exposure to these radiations in nuclear facilities is measured by devices called dosimeters. The devices are generally worn on the torso and are monitored by health physics division to report the radiation dose received by the personnel. However, this approach is not proactive--since the dosimeters reflect the dose that has already been absorbed in the body of the wearer.

This work presents a scheme to proactively avoid large dose acquisition at radiation-prone facilities. The work was divided into three major segments: (i) …

Cable Analysis For Electromagnetic Compatibility Issues, Guanghua Li

Doctoral Dissertations

"This dissertation consists of three papers. In the first paper, a high-sensitivity resonant electric field probe was designed, consisting of an LC resonator loaded by quarter-wave transformers. At the resonant frequency of 1.577 GHz, the measured |S₂₁| from a matched trace to the resonant probe was approximately 6.6 dB higher than that of an equivalently sized broadband probe.

In the second paper, a method for creating a simple SPICE model is proposed such that the SPICE model allows prediction of radiated emissions in component level tests. The radiation from the ground connections between the cables and return plane …

Synthesis Of Radioactive Nanostructures In A Research Nuclear Reactor, Maria Camila Garcia Toro

Masters Theses

In this work, the synthesis of radioactive nanostructures by water radiolysis was studied. The irradiation processes were done in the Missouri University of Science and Technology research nuclear reactor (MSTR).

Radioactive gold nanoparticles (AuNPs) were synthesized from aqueous solutions containing the metal salt precursors by radiolysis of water. Seven different samples were irradiated at 200kW of thermal power for 0.5, 1, 3, 5, 10, 30, and 60 minutes. The average sizes of the obtained nanoparticles ranged from 3 nm to 400 nm, it was found that the particle size decreased with the irradiation time. Some agglomerations of particles were found …

Single Phase Gas Flow Response Of Fractured Horizontal And Vertical Wells To Repeated Production, Divya Kandlakunta

Masters Theses

"Historically, the conventional approach to well production has been to produce continuously, minimizing interruptions to flow insofar as possible. Yet some operators have observed improved well flow rates and ultimate recovery after a significant well shut-in periods. These production increases have not been documented. This study investigates the production impact of cyclic production/shut-in on fractured vertical and horizontal gas well performance.

A numerical reservoir model in Stimplan software was used to model production in fracture stimulated vertical and horizontal gas wells. Reservoir permeability is varied over a range of 0.0001 md to 1 md, and the shut-in period was varied …

Studies On Flocculation Of Fine Mineral Tailings Using Novel Polyacrylamide Based Polymer, Simin Khatibi

Masters Theses

"One of the important features in managing or treating sulfide fine tailings is separating solids from liquid by settling test. This thesis presents results of studied conducted on flocculation of Kaolin suspensions (a model tailings) and sulfide mineral tailings. Two polymers (PAM and Al-PAM) were tested as flocculants. The zeta potential value of slurries was measured by Nano Zetasizer device.

Al-PAM was found to be more effective for flocculation of kaolinite samples and also sulfide samples while PAM with used concentration was not. This study represents the power of flocculation as a possible solution to deal with industrial tailings"--Abstract, page …

Computational Fluid Dynamic Analysis In High Permeability Hydraulic Fractured Horizontal Gas Wells, Hrithu Vasudevan

Masters Theses

"Hydraulic fracturing of horizontal wells in unconventional reservoirs has become the dominant type of well completion performed in the United States. In very low permeability reservoirs (~.00001-.0001 mD), the wellbore is aligned with the minimum horizontal stress, and the completion includes multiple transverse fractures. These fractures may be placed with either open hole sleeve type completion systems (OHMS), or cased hole plug and perf systems (P-n-P). In slightly higher permeability reservoirs (1 to 10 mD) multiple longitudinal fractures have been found to be preferred to completions with transverse fractures.

This study presents an evaluation of gas well productivity for both …

การลดของเสียในกระบวนการผลิตอุปกรณ์ส่งและรับสัญญาณ, กนกวรรณ บุญฤทธิ์ศักดิ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อลดปริมาณของเสียอุปกรณ์ส่งและรับสัญญาณทางแสงที่เกิดจากค่าแรงเฉือนของการยึดติดระหว่างชิ้นส่วนเลนส์บนแผ่นประกอบวงจรไฟฟ้าชนิดยืดหยุ่น (FPCBA: Flexible Printed Circuit Board Assembly) ซึ่งมีกระบวนการผลิตเริ่มจาก (1) นำแผ่นประกอบวงจรไฟฟ้าชนิดยืดหยุ่น (FPCBA) ที่ผ่านการประกอบวงจรอิเล็กทรอนิกส์แล้วมาทำความสะอาด (2) หยอดกาวชนิด Urethane Acrylate (UA) จำนวน 8 ตำแหน่งบนแผ่น FPCBA (3) ยิงและอบด้วยแสงยูวี (4) หยอดกาวชนิดEpoxyสีดำ (5) อบด้วยความร้อน ดำเนินการวิเคราะห์หาสาเหตุโดย (1) ศึกษาความสัมพันธ์ระหว่างค่าแรงเฉือนที่ได้กับจำนวนการเกิดสีขาวขุ่นของกาวUA บนแผ่น FPCBA (2) ตรวจสอบลักษณะข้อบกพร่องของการยึดติดกาวด้วยกล้องจุลทรรศน์เล็กตรอนแบบส่องกราด (3) วิเคราะห์องค์ประกอบของชนิดคราบกาวและตรวจหาหมู่ฟังก์ชันด้วยเครื่อง FTIR (Fourier Transform Infrared Spectrometer) (4) วิเคราะห์หาขั้นตอนที่ทำให้เกิดของเสีย โดยพิจารณาจากขั้นตอนท้ายไปหน้า (5) ดำเนินการปรับปรุง ผลการศึกษาพบว่า 1) ค่าแรงเฉือนมีค่าลดลงเมื่อมีจำนวนตำแหน่งของกาวUA เปลี่ยนสีจากใสเป็นขาวขุ่นมากขึ้น 2) ลักษณะของเสียกาวUAขาวขุ่นเกิดขึ้นที่ขั้นตอนการทำความสะอาด โดยวิธีทำความสะอาดของพนักงานมีอิทธิพลมากที่สุด ซึ่งลักษณะของเสียกาวUA ขาวขุ่นเกิดจากกาวUA ที่ไม่ยึดติดบน FPCBA ซึ่งเกิดจากการทำความสะอาดที่ไม่เพียงพอ 3) ระยะทางในการทำความสะอาดต่อก้านสำลีและการทำซ้ำที่ใช้เช็ดทำความสะอาด ส่งผลต่อการเกิดกาวUAขาวขุ่น 4) การใช้สารระเหยทำความสะอาดชิ้นงานชนิด IPA (Isopropyl Alcohol) ที่มีจุดเดือด 82.6°C ซึ่งใกล้เคียงกับอุณหภูมิที่ใช้ในขั้นตอนการอบชิ้นงานเท่ากับ90±5°C ซึ่งเป็นขั้นตอนสุดท้าย เป็นสาเหตุให้กาวUA เปลี่ยนสีจากใสเป็นขาวขุ่น เนื่องจากไอระเหยที่ไล่ออกไม่หมด 5) การใช้สารระเหยชนิดเมธนอล (Methanol) ที่มีจุดเดือด 64.7°C ทดแทน IPA พบว่าของเสียจากกาวUA ขาวขุ่นลดลงจากเดิมก่อนศึกษา 33% เป็น 7% และไม่เกิดกาวขาวขุ่นอีกเลย ตามลำดับ

Real-Time Monitoring Of Personal Exposures To Carbon Dioxide, Elliott T. Gall, Toby Cheung, Irvan Luhung, Stefano Schiavon, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

Elevated indoor CO₂ levels are indicative of insufficient ventilation in occupied spaces and correlate with elevated concentrations of pollutants of indoor origin. Adverse health and well-being outcomes associated with elevated indoor CO₂ levels are based on CO₂ as a proxy, although some emerging evidence suggests CO₂ itself may impact human cognition. Using portable monitors, we conducted an exposure study with 16 subjects in Singapore to understand the levels, dynamics and influencing factors of personal exposure to CO₂. Participants carried a CO₂ monitor continuously for 7-day periods recording their exposure levels at 1-min intervals. …

Elasto-Plastic Transient Dynamic Response Of Tubular Section Steel Cantilever Beam Under Impact Loading, Alial Aloosi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

This paper presents the outcome of an experimental and theoretical investigation into the loadcarrying capacity of Fiber Reinforced Polymer (FRP) I-section beams subjected to four-point loading. The overall lateral-torsional buckling, web and flange local buckling as well as material rupture load estimates are also made using the American Society of Civil Engineers#x2019; Load and Resistance Factor Design (ASCELRFD) Pre-Standard for FRP Structures. Lateral-torsional buckling failure mode is found to govern for each of the beams studied. The study also revealed that the height of applied loads relative to the shear center has a very significant influence on lateral-torsional buckling load …

Physical Modeling Of The Atmospheric Boundary Layer In The University Of New Hampshire’S Flow Physics Facility, Stephanie Gilooly, Gregory Taylor-Power

Honors Theses and Capstones

The atmospheric boundary layer is the lowest part of the atmosphere, and is defined by a region from the surface of the earth to approximately 500-1000m altitude in which air velocity changes from zero at the surface to the velocity of the wind at a certain altitude. The type of atmospheric boundary layer is characterized by the terrain it encounters, varying from open sea and mud flats to suburban areas and city centers with high- and low-rise buildings. The goal of this project is to generate different types of atmospheric boundary layers for scale model testing in the UNH Flow …

Electrochemical Detection Of Antioxidants, Garrett Thompson

Honors Theses and Capstones

No abstract provided.

Creating Multi-Functional G-Code For Multi-Process Additive Manufacturing, Efrain Aguilera Jr

Open Access Theses & Dissertations

Additive manufacturing (AM) started over thirty years ago and with it a manufacturing revolution that moves industrial production into the personal home. With recent interest shifting into multi-functional parts fabricated through AM technologies, unified systems are being developed. Merging different manufacturing technologies into one single machine is a challenge but undergoing research has shown promise in the development of multi-functional systems. Concurrent work is being done in the software, automation, and hardware aspect of multi-functional systems. An effort to use industry compatible Computer Aided Design (CAD) software to design multi-functional parts including circuits, micro-machining, and foil embedding then exporting and …

Treatment Of Dissolved Metals For Direct Potable Reuse, Cesar Alberto Alvarez

Open Access Theses & Dissertations

In the process of direct potable reuse (DPR), the bulk of the removal of dissolved metals removal is accomplished by reverse osmosis. This treatment is especially important in wastewater containing contaminants from industrial processes. The goal of this research was to evaluate the performance of DPR with respect to the removal of salinity and dissolved metals to meet drinking standards. Samples were collected from the El Paso Water Utilities Advanced Water Purification pilot system throughout various points in the treatment process. The samples were analyzed for their concentration of ions with Ion Chromatography (IC) and dissolved metals using an Inductively …

A Discretionary Lane Changing Decision Model Based On Fuzzy Inference System, Esmaeil Balal

Open Access Theses & Dissertations

A lane changing event involves up to five vehicles: the subject vehicle, preceding and following vehicles in the original lane, and the preceding and following vehicles in the target lane. Understanding the behavior of the subject vehicle with respect to the surrounding vehicles is fundamental to the study of the safety of a lane change maneuver and for the modeling of lane changing behavior. First, the statistical properties of 10 lane changing parameters were defined and studied using the Next Generation SIMulation (NGSIM) vehicle trajectory data collected at the I-80 Freeway in Emeryville, California, and then tested with data collected …

Materials Characterization Of Deposits On Starboard (Inboard) Elevon Actuator Shaft Recovered From Space Shuttle Columbia, Mayra Contreras

Open Access Theses & Dissertations

With the new era of space exploration upon us and the Orion spacecraft currently being tested, which would replace the Space Shuttle as the orbiter that will transport humans into space once again, safety assurance is the main component for a successful mission. Aerospace materials have always played a big role when it comes to safety assurance. Having the knowledge of what materials are suitable to keep using when designing the future spacecraft that will take humans to Mars is fundamental in order to be confident that the vehicle and all that comprises it will function as envisioned. Expanding the …

A Cracking Methodology To Assess Fracture And Fatigue Properties Of Asphalt Concrete Mixtures Using Overlay Tester, Victor M. Garcia

Open Access Theses & Dissertations

Several highway agencies have either implemented or considered implementing performance tests to predict the cracking potential of asphalt concrete (AC) mixtures in the laboratory setting. One such test, the Overlay Tester (OT) test, measures the number of cycles to failure of the AC specimens by simulating the opening and closing of the cracks induced by daily temperature variations and high tensile strain generated by the traffic load. The variability of the OT test results is expressed as a major concern in reliably characterizing the cracking potential of the AC mixes.

The performance of the OT test, in general, and current …