Engineering Commons^™

Ptfe-Based Microreactor System For The Continuous Synthesis Of Full-Visible-Spectrum Emitting Cesium Lead Halide Perovskite Nanocrystals, Chengxi Zhang, Weiling Luan, Yuhang Yin, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX₃, X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19–35 nm, high fluorescence quantum yield of 47.8–90.55%, and photoluminescence emission in the range of 450–700 nm. For the same precursor concentrations, the photoluminescence emission peak generally increases with increasing reaction temperature, …

Design And Simulation Of An 8-Bit Successive Approximation Register Charge-Redistribution Analog-To-Digital Converter, Sumit K. Verma

Electrical Engineering Theses

The thesis initially investigates the history of the monolithic ADCs. The next chapter explores the different types of ADCs available in the market today. Next, the operation of a 4-bit SAR ADC has been studied. Based on this analysis, an 8-bit charge-redistribution SAR ADC has been designed and simulated with Multisim (National Instruments, Austin, TX). The design is divided into different blocks which are individually implemented and tested. Level-1 SPICE MOSFET models representative of 5μm devices were used wherever individual MOSFETs were used in the design. Finally, the power dissipation during the conversion period was also estimated. The supply voltage …

Ensemble Machine Learning And Forecasting Can Achieve 99% Uptime For Rural Handpumps, Daniel L. Wilson, Jeremy R. Coyle, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Broken water pumps continue to impede efforts to deliver clean and economically-viable water to the global poor. The literature has demonstrated that customers’ health benefits and willingness to pay for clean water are best realized when clean water infrastructure performs extremely well (>99% uptime). In this paper, we used sensor data from 42 Afridev-brand handpumps observed for 14 months in western Kenya to demonstrate how sensors and supervised ensemble machine learning could be used to increase total fleet uptime from a best-practices baseline of about 70% to >99%. We accomplish this increase in uptime by forecasting pump failures and …

Classification Of Daily Activities For The Elderly Using Wearable Sensors, Jian Liu, Jeehoon Sohn, Sukwon Kim

Computer Sciences and Electrical Engineering Faculty Research

Monitoring of activities of daily living (ADL) using wearable sensors can provide an objective indication of the activity levels or restrictions experienced by patients or elderly. The current study presented a two-sensor ADL classification method designed and tested specifically with elderly subjects. Ten healthy elderly were involved in a laboratory testing with 6 types of daily activities. Two inertial measurement units were attached to the thigh and the trunk of each subject. The results indicated an overall rate of misdetection being 2.8%. The findings of the current study can be used as the first step towards a more comprehensive activity …

How We Compute N Matters To Estimates Of Mixing In Stratified Flows, Robert S. Arthur, Subhas K. Venayagamoorthy, Jeffrey R. Koseff, Oliver B. Fringer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Most commonly used models for turbulent mixing in the ocean rely on a background stratification against which turbulence must work to stir the fluid. While this background stratification is typically well defined in idealized numerical models, it is more difficult to capture in observations. Here, a potential discrepancy in ocean mixing estimates due to the chosen calculation of the background stratification is explored using direct numerical simulation data of breaking internal waves on slopes. Two different methods for computing the buoyancy frequency, one based on a three-dimensionally sorted density field (often used in numerical models) and the other based on …

On The Propagation Of Gravity Currents Over And Through A Submerged Array Of Circular Cylinders, Jian Zhou, Claudia Cenedese, Tim Williams, Megan Ball, Subhas K. Venayagamoorthy, Roger I. Nokes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The propagation of full-depth lock-exchange bottom gravity currents past a submerged array of circular cylinders is investigated using laboratory experiments and large eddy simulations. Firstly, to investigate the front velocity of gravity currents across the whole range of array density (i.e. the volume fraction of solids), the array is densified from a flatbed towards a solid slab under a particular submergence ratio, where is the flow depth and is the array height. The time-averaged front velocity in the slumping phase of the gravity current is found to first decrease and then increase with increasing. Next, a new geometrical framework consisting …

Silica Formation With Nanofiber Morphology Via Helical Display Of The Silaffin R5 Peptide On A Filamentous Bacteriophage, In-Wong Song, Hyojung Park, Jung Han Park, Hyunook Kim, Seong Hun Kim, Justyn Jaworski, Byoung-In Sang, Sung Yi

Bioengineering Faculty Publications - Archive

Biological systems often generate unique and useful structures, which can have industrial relevance either as direct components or as an inspiration for biomimetic materials. For fabrication of nanoscale silica structures, we explored the use of the silaffin R5 peptide from Cylindrotheca fusiformis expressed on the surface of the fd bacteriophage. By utilizing the biomineralizing peptide component displayed on the bacteriophage surface, we found that low concentrations (0.09 mg/mL of the R5 bacteriophage, below the concentration range used in other studies) could be used to create silica nanofibers. An additional benefit of this approach is the ability of our R5-displaying phage …

Suspension-Driven Gravity Surges On Horizontal Surfaces: Effect Of The Initial Shape, ‪Nadim Zgheib, T. Bonometti, S. Balachandar

Mechanical Engineering Faculty Publications

We present results from highly resolved direct numerical simulations of canonical (axisymmetric and planar) and non-canonical (rectangular) configurations of horizontal suspension-driven gravity surges. We show that the dynamics along the initial minor and major axis of a rectangular release are roughly similar to that of a planar and axisymmetric current, respectively. However, contrary to expectation, we observe under certain conditions the final extent of the deposit from finite releases to surpass that from an equivalent planar current. This is attributed to a converging flow of the particle-laden mixture toward the initial minor axis, a behaviour that was previously reported for …

Non-Additive Impacts Of Covalent Cross-Linking On The Viscoelastic Nanomechanics Of Ionic Polyelectrolyte Complexes, B. Han, T. Ma, J. H. Vergara, Giuseppe R. Palmese, J. Yin, D. Le

Henry M. Rowan College of Engineering Departmental Research

This study elucidates the influences of adding covalent cross-linking on the nanomechanical viscoelasticity of ionically cross-linked polyelectrolyte networks. Using layer-by-layer (LbL) assembled PAH/PAA networks, we report how adding covalent amide cross-links changes the degree of swelling, indentation modulus, and force relaxation behaviors with varying solution conditions such as pH and ionic strength, which modulate the ionic cross-link density and fixed charge density. The addition of covalent cross-linking increases both the modulus and degree of elasticity through providing permanent anchorage to the ionically linked networks. Such addition also strongly increases the relaxation times at net neutral, less swollen states. These results …

Stewardship Of International Bim Programmes: Lessons For Ireland, Barry Mcauley, Alan Hore, Roger West, Shiyao Kuang

Conference papers

The support by central government of national Building Information Modelling (BIM) programmes is common throughout the developed world today. To further understand how the different international governments have supported their BIM programmes the BIM Innovation Capability Programme (BICP) research team in Ireland recently completed a comprehensive Global BIM Study to help inform the National BIM Council (NBC) of Ireland in developing a Roadmap to Digital Transition for Ireland’s Construction Sector. This paper details the findings of a more concentrated investigation on a selection of jurisdictions on how particular international BIM programmes are orgainsed, managed and the level of governmental support …

Level 1 Before Level 2 – The Irish Bim Mandate, Robert Moore

Conference papers

Government Contracts Committee for Construction (GCCC) has prepared a position paper titled ‘A Public Sector BIM Adoption Strategy’, which outlines the context and rationale for the adoption of BIM and puts forward a proposed timeline for adoption, the purpose of this position paper is to invite a response from industry [1]. This paper analyses the position paper on the subject of the implementation of the proposed mandate. The author defines what is implied by UK BIM Levels 0, 1, 2 and 3, and collates the responses from industry to the position paper regarding the implementation plan. This position paper is …

Ireland’S Bim Macro Adoption Study: Establishing Ireland’S Bim Maturity, Barry Mcauley, Alan Hore, Roger West, Mohamad Kassem, Shiyao Kuang

Conference papers

Since 2016 the BIM Innovation Capability Programme (BICP) has captured the capability of the Irish Construction Industry’s and the Higher Education Institutes’ (HEIs) response to the increased requirement for BIM on Irish construction and engineering projects. One of the primary responsibilities of the BICP research team is to collate data to assist the National BIM Council of Ireland in the formulation of a National BIM Roadmap. To assist the Council with this task the BICP research team applied five macro BIM maturity conceptual models to assess Ireland’s BIM maturity. The results from the models were further utilised to develop a …

Effect Of Oxide On Surface Tension Of Molten Metal, Chunkai Li, Yu Shi, Yufen Gu, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Oxides as one of the commonly activating fluxes used in active tungsten inert gas welding (A-TIG welding) can dramatically increase the penetration depth to 2–4 times that of conventional welding. Using the oscillation principle of inviscid fluid, a robust method is developed to measure the average surface tension of molten metal during A-TIG welding for four different oxide activating fluxes of B₂O₃, TiO₂, SiO₂, and MgO. The experimental results suggest that the oxygen released from the decomposition of oxides is the dominant factor contributing to the change of the surface tension, which …

Transient Analysis Of Fracture Initiation In A Coupled Thermoelastic Solid, Louis Milton Brock

Mechanical Engineering Faculty Publications

An isotropic, thermoelastic solid is initially at rest at uniform (absolute) temperature, and contains a semi-infinite, plane crack. Application of in-plane and normal point forces to each face of the crack causes transient 3D growth. The related problem of discontinuities in temperature and displacement that exist on regions that exhibit dynamic similarity is first considered. Asymptotic expressions, whose inverses are valid near the crack edges for short times, are obtained in integral transform space. These lead to equations of the Wiener–Hopf type for the fracture problem. Analytical solutions are obtained and, upon inversion, subjected to a dynamic energy release rate …

Load Model Verification, Validation And Calibration Framework By Statistical Analysis On Field Data, Xiangqing Jiao, Yuan Liao, Thai Nguyen

Electrical and Computer Engineering Faculty Publications

Accurate load models are critical for power system analysis and operation. A large amount of research work has been done on load modeling. Most of the existing research focuses on developing load models, while little has been done on developing formal load model verification and validation (V&V) methodologies or procedures. Most of the existing load model validation is based on qualitative rather than quantitative analysis. In addition, not all aspects of model V&V problem have been addressed by the existing approaches. To complement the existing methods, this paper proposes a novel load model verification and validation framework that can systematically …

Evolution Of The Pore Size Distribution In Sheared Binary Glasses, Nikolai V. Priezjev, Maxim A. Makeev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are carried out to investigate mechanical properties and porous structure of binary glasses subjected to steady shear. The model vitreous systems were prepared via thermal quench at constant volume to a temperature well below the glass transition. The quiescent samples are characterized by a relatively narrow pore size distribution whose mean size is larger at lower glass densities. We find that in the linear regime of deformation, the shear modulus is a strong function of porosity, and the individual pores become slightly stretched while their structural topology remains unaffected. By contrast, with further increasing strain, the shear …

Tracking You Through Dns Traffic: Linking User Sessions By Clustering With Dirichlet Mixture Model, Mingxuan Sun, Junjie Zhang, Guangyue Xu, Dae Wook Kim

Computer Science and Engineering Faculty Publications

The Domain Name System (DNS), which does not encrypt domain names such as "bank.us" and "dentalcare.com", commonly accurately reflects the specific network services. Therefore, DNS-based behavioral analysis is extremely attractive for many applications such as forensics investigation and online advertisement. Traditionally, a user can be trivially and uniquely identified by the device’s IP address if it is static (i.e., a desktop or a laptop). As more and more wireless and mobile devices are deeply ingrained in our lives and the dynamic IP address such as DHCP has been widely applied, it becomes almost impossible to use one IP address to …

Characterizing The Electromechanical Response Of Flexible Foam For Multifunctional Impact-Sensing Applications, Evan Troy Bird

Theses and Dissertations

Flexible foams have unique properties that make them well-suited to several engineering systems. They are often used in impact-related applications because of their superior energy absorption performance. Many multifunctional materials are also derived from flexible foams due to their high customizability, which allows them to satisfy a wide range of performance requirements. Though flexible foams have high potential in these and other classes of material applications, their success relies on the proper characterization of their complex behavior. This thesis promotes the application of flexible foams by characterizing their electromechanical response through both experimental and theoretical approaches. One study in this …

A Gal-Ms Device To Evaluate Cell Migratory Response To Combined Galvano-Chemotactic Fields, Shawn Mishra, Maribel Vazquez

Publications and Research

Electric fields have been studied extensively in biomedical engineering (BME) for numerous regenerative therapies. Recent studies have begun to examine the biological effects of electric fields in combination with other environmental cues, such as tissue-engineered extracellular matrices (ECM), chemical gradient profiles, and time-dependent temperature gradients. In the nervous system, cell migration driven by electrical fields, or galvanotaxis, has been most recently studied in transcranial direct stimulation (TCDS), spinal cord repair and tumor treating fields (TTF). The cell migratory response to galvano-combinatory fields, such as magnetic fields, chemical gradients, or heat shock, has only recently been explored. In the visual system, …

Direct Digital Manufacturing Of Multi-Layer Wideband Ku-Band Patch Antennas, Merve Kacar

USF Tampa Graduate Theses and Dissertations

Design and performance of fully-printed Ku-band aperture coupled patch antennas fabricated by a direct digital manufacturing (DDM) approach that integrates fused deposition modeling (FDM) of acrylonitrile butadiene styrene (ABS) thermoplastic with in-situ micro-dispensing of conductive silver paste (CB028) are reported. Microstrip line characterizations are performed and demonstrate that misalignment of ABS substrate deposition direction with microstrip line micro-dispensing direction can degrade the effective conductivity up to 60% within the Ku-band, and must be taken into consideration in antenna array feed network designs. Specically, over 125 µm thick ABS substrate, RF loss of 0.052 dB/mm is obtained at 18 GHz, demonstrating …

Measuring Walls In Accordance With Arm4 - An Introductory Demonstration, Tony Cunningham

Other Resources

This demonstration involves the measurement of 'traditional' external brick and block cavity walls and internal block partitions. The demonstration is addressed to students taking (Irish) measurement or quantities modules at first year / entry level of quantity surveying related programmes. The worked example has been carried out using traditional handwritten quantity surveying processes on traditional dimension paper. It is acknowledged that this would be carried out using measurement software or on-screen measurement technology in actual practice. The traditional handwritten approach has been retained in order to enable novice students to develop the necessary measurement skills and build confidence through direct …

Solar System Battery Backups For Reactor Coolant Pumps During Electricity Outages Resulting From Natural Disasters, Md. Shamsul Huda Sohel

International Journal of Nuclear Security

In a nuclear power plant, its coolant system is major safety equipment. Coolant system failure causes several accidents in nuclear history. There are so many causes for coolant system failure. One of them is lack of electric power for coolant pumps. In typically NPP there is backup system for power redundancy. In this article, focus on reactor coolant system and its backup power when main grid lines failure. Here discuss about solar backup power for batteries and increases a safety lines for reactor coolant pumps. So, our main goal is providing a battery backup from reliable natural source and ensuring …

Development Of Biomimetic Membrane Assemblies On Microspheres For High-Throughput And Multiplexable Studies, Nadiezda P. Fernandez Oropeza

Biomedical Engineering ETDs

Membranes and membrane-associated components are the target of approximately 60% of the current drugs, of synthetic materials, such as polymers, which are used for drug delivery purposes and of other biomolecules, such as endotoxins, which gain entry into the cell by disrupting the membrane. Therefore, the development of biomimetic membrane assemblies allows the study of different biological processes in which cell membranes play an important role, and the characterization and screening of drug delivery tools and other membrane-bound components.

Since its development, membrane assemblies on planar silica surfaces have been the method of choice to study membrane-associated and membrane-bound components. …

Analysis Of The Acid-Base Balance Of Mainstream Tobacco Smoke And Its Effect On The Gas/Particle Partitioning Of Nicotine, Amy Kathleen Devita-Mcbride

Dissertations and Theses

Tobacco smoke particulate matter (PM) is a complex mixture of condensed organic compounds, with about 5 to 10% water. Its general properties are similar in some respects to that of atmospheric organic aerosol PM and thus provides a useful surrogate when studying atmospheric PM. Due to its ability to undergo acid-base chemistry, nicotine is of particular interest in the tobacco smoke system. The gas/particle partitioning of nicotine depends on the protonation state of nicotine in the particles, so the distribution of nicotine between these phases provides a means of understanding the acid-base balance in the tobacco smoke system. The goal …

Synthesis Of Graphene And Graphene-Based Composite Membrane, Yuanjun Fan

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Vibration membrane equipped for earphone requires high performance in both mechanical properties and electronic properties. With extraordinary properties on both, graphene and graphene-based composite materials appear as a promising candidate for this application. Chemical vapor deposition (CVD) is believed to be the most convenient way to synthesize a large area (on scale of square centimeters) as well as a homogeneous thickness for the membrane. The thesis focuses on applying control variable experiment method to analyze different effects on mechanical property of the two CVD setting parameters: cooling rate, and hydrocarbon precursor. For isolating the specimens efficiently, a modified electrochemical method …

Development Of Some Scalable Pattern Recognition Algorithms For Real Life Data Analysis, Partha Garai

Doctoral Theses

A huge amount of data is being generated continuously as a result of recent advancement and wide use of high-throughput technologies. With the rapid increase in size of data distributed worldwide, understanding the data has become critical. In this regard, dimensionality reduction and clustering have become the necessary preprocessing steps of multiple research areas and applications. One of the important problems of real life large data sets is uncertainty. Some of the sources of this uncertainty include imprecision in computation and vagueness in class denitions. The uncertainty may also be present in the denition of class membership function. In this …

Reengineering A 2-Tier Database Application With Software Architecture, Hong G. Jung

ASA Multidisciplinary Research Symposium

The purpose of this research is to demonstrate how to reengineer a legacy Database Application using to a target system with MVC and 3-layered architecture. A Coffee Inventory Management database application is used for legacy application. The benefits of the reengineering are discussed.

A Case Study Of Applying Node.Js In Basic Drone Programming And Web Development, Jeremy Kim, Alireza Khamesipour, Charith Atapattu, Mahdi Moradi, Abdallah Jameel Al-Khayri

ASA Multidisciplinary Research Symposium

In this research, we first seek to determine if basic drone programming can give insight to learning Node.js and be applied to web development through using Node.js and the Drone. Second, we seek how drone programming can help student recruitment by using a showcase.

2017 Robinson Engine Design, Christian Klem, Alli Giblin, James Gross

ASA Multidisciplinary Research Symposium

The Robinson-Malibu patent is an engine design theory that will reduce emissions, increase MPGs and performance.

Morphological, Thermal And Oxygen Barrier Properties Plasticized Film Polylactic Acid, Kurniawan Yuniarto, Bruce A. Welt, Foliatini -, Hanafi -, Candra Irawan

Journal of Applied Packaging Research

Introducing plasticizer poly(ethylene glycol) (PEG400) was applied into poly(lactic acid) (PLA) to produce film matrix packaging by direct casting. Non mechanical properties were carried out plasticized PLA including morphology, crystallinity structure and degree, thermal properties and oxygen barrier properties. Plasticized PLA revealed improving surface structure of PLA film matrix form fractures and homogenous film were achieved at 5% PEG 400. Chromatogram PLA and plasticized PLA were categorized crystal structure an α-form crystal. Intercalated and exfoliated structure did not occur significantly due to dispersion PEG 400 in the matrix but indicated dispersion structure. Thermal properties did not improve plasticized PLA significantly …