Engineering Commons^™

Spatial Positioning And Operating Parameters Of A Rotary Bell Sprayer: 3d Mapping Of Droplet Size Distributions, Adnan Darwish Ahmad, Binit B. Singh, Mark Doerre, Ahmad M. Abubaker, Masoud Arabghahestani, Ahmad A. Salaimeh, Nelson K. Akafuah

Institute of Research for Technology Development Faculty Publications

In this study, we evaluated the fundamental physical behavior during droplet formation and flow from a rotary bell spray in the absence of an electrostatic field. The impact of a wide range of operating parameters of the rotary bell sprayer, such as flow rates, rotational speeds, and spatial positioning, on droplet sizes and size distributions using a three-dimensional (3-D) mapping was studied. The results showed that increasing the rotational speed caused the Sauter mean diameter of the droplets to decrease while increasing flow rate increased the droplet sizes. The rotational speed effect, however, was dominant compared to the effect of …

Why Reinventing The Wheels? An Empirical Study On Library Reuse And Re-Implementation, Bowen Xu, Le An, Ferdian Thung, Foutse Khomh, David Lo

Research Collection School Of Computing and Information Systems

Nowadays, with the rapid growth of open source software (OSS), library reuse becomes more and more popular since a large amount of third- party libraries are available to download and reuse. A deeper understanding on why developers reuse a library (i.e., replacing self-implemented code with an external library) or re-implement a library (i.e., replacing an imported external library with self-implemented code) could help researchers better understand the factors that developers are concerned with when reusing code. This understanding can then be used to improve existing libraries and API recommendation tools for researchers and practitioners by using the developers concerns identified …

Materials Selection Of 3d Printing Filament And Utilization Of Recycled Polyethylene Terephthalate (Pet) In A Redesigned Breadboard, Mark Keanu James E. Exconde, Julie Anne A. Co, Jill Z. Manapat, Eduardo R. Magdaluyo Jr.

Goal 12: Responsible Consumption and Production

The demand for a novel and sustainable alternative materials for 3D printer filaments has been knowingly increasing. One alternative source for the filament is to reuse and recycle post-consumer plastic products, which is also a compelling approach to conserve energy and sustain the environment. Thus, this study is focused on the materials selection of virgin polymer resins and recycled post-consumer plastics for use in 3D printer filaments. A multi-criteria decision method of Elimination and Choice Expressing the Reality (ELECTRE) was utilized to determine the best materials for 3D printer filaments. The study has shown that the virgin low-density polyethylene (LDPE) …

Segmentation Of Severe Occupational Incidents In Agribusiness Industries Using Latent Class Clustering, Fatemeh Davoudi Kakhki, Steven Freeman, Gretchen Mosher

Faculty Publications

One of the principle objectives in occupational safety analysis is to identify the key factors that affect the severity of an incident. To identify risk groups of occupational incidents and the factors associated with them, statistical analysis of workers’ compensation claims data is performed using latent class clustering, for the segmentation of 1031 severe occupational incidents in agribusiness industries in the Midwest region of the United States between 2008–2016. In this study, severe incidents are those with workers’ compensation costs equal to or greater than $100,000 (USD). Based on the latent class clustering results, three risk groups are identified with …

Trends In Drought Over The Northeast United States, Nir Y. Krakauer, Tarendra Lakhankar, Damien Hudson

Publications and Research

The Northeast United States is a generally wet region that has had substantial increases in mean precipitation over the past decades, but also experiences damaging droughts. We evaluated drought frequency, intensity, and duration trends in the region over the period 1901–2015. We used a dataset of Standardized Precipitation Evapotranspiration Index (SPEI), a measure of water balance based on meteorology that is computed at multiple timescales. It was found that the frequency of droughts decreased over this period, but their average intensity and duration did not show consistent changes. There was an increase in mean SPEI, indicating mostly wetter conditions, but …

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg

Theses and Dissertations

Acute Myocardial Infarction (AMI) is the leading cause of worldwide death and disability, and approximately 720,000 Americans will experience an AMI in 2018. Studies have shown that rapid hypothermia therapy (<35°C) before reperfusion in patients with AMI can reduce infarct size by 37%. Localized therapeutic hypothermia has proven the potential to cool heart tissue rapidly following AMI, 3°C in 5 minutes. Using Materialise Mimics digital imaging software and the finite volume method we analyzed temperature distributions in six patient-specific left main coronary artery (LMCA) models. A mock circulatory loop was used to determine the exiting temperatures of a standard 7 Fr catheter to feed into our model with flow rates ranging from 29.2 ml/min to 68.85 ml/min. Our work showed that therapeutic hypothermia (TH) temperatures were evident at the outlets of three out of all six heart models, which varied in each left anterior descending (LAD) and left circumflex (LCX) artery depending on flowrate. Results of this study indicate that biovariability in patient-specific vascular structures significantly impacts therapeutic hypothermia (TH) treatment methods. These results indicate that further research is needed to examine more accurate physiological effects, such as pulsatile flow and vessel wall thickness. Future models will be used to provide insight to guide more efficient TH device designs and operation parameters to optimize patient outcomes following AMI.

Competence Of A Spray Passive Down-Draft Evaporative Cooling (Pdec) System For Space Cooling, Daeho Kang, Richard K. Strand

Publications and Research

A spray PDEC system has been relatively less considered than other passive cooling strategies as one of the viable low-energy solutions in the cooling of buildings while having a great potential in energy savings. This study is intended to evaluate the capability of a spray PDEC system for space cooling. It comprises four simulation scenarios to see the system response and influence of indoor thermal environment when a spray PDEC system is adopted as a primary cooling system in two different climates. The simulation results show that a spray PDEC system causes a substantial variation in the indoor thermal environment …

Model Based Analysis Of The Accuracy And Precision Of Auscultatory Blood Pressure Measurements In Patients With Atrial Fibrillation, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

Accurate measurement of blood pressure in the presence of atrial fibrillation remains an open problem. The present study combines the techniques of stochastic mathematical modeling with physiological models of the systemic circulation, cuff, and arm (1) to explore mechanisms underlying both the lack of accuracy and the lack of precision in cuff-based arterial pressure measurements during atrial fibrillation and (2) to develop strategies to correct for errors. Both the cardiovascular system and the measurement technique are described using mathematics, including both numerical techniques and analytical probability theory. Preliminary results with numerical models suggested that, despite variability, average systolic pressures tend …

Force Oscillations Distort Avalanche Shapes, Louis W. Mcfaul, Wendelin J. Wright, Jordan Sickle, Karin A. Dahmen

Faculty Journal Articles

Contradictory scaling behavior in experiments testing the principle of universality may be due to external oscillations. Thus, the effect of damped oscillatory external forces on slip avalanches in slowly deformed solids is simulated using a mean-field model. Akin to a resonance effect, oscillatory driving forces change the dynamics of avalanches with durations close to the oscillation period. This problem can be avoided by tuning mechanical resonance frequencies away from the range of the inverse avalanche durations. The results provide critical guidance for experimental tests for universality and a quantitative understanding of avalanche dynamics under a wide range of driving conditions.

Quantification Of Heat Flows Through Building Entrance Doors On A Winter Day, Daeho Kang

Publications and Research

The current methods for the prediction of the heat flow through building entrance doors have been used for years while involved with a certain degree of uncertainty. This paper describes an experimental method that accurately quantified such heat flow. The experiment monitored local environmental parameters in a college building on a cold winter day. The results of the experiment demonstrated that the experimental method is viable to accurately estimate the heat flow throughout the entrance doors and the presence of a vestibule moderated heat losses from the conditioned area. The results will be used for validating the existing methods.

Effect Of Surfactant, Oil:Water Ratio And Temperature On The Rheology Of Emulsion-Suspension Complex Fluids: Implications For Oil-Based Drilling Fluids, Gilles Landry Numkam

LSU Doctoral Dissertations

Drilling fluids are non-Newtonian mixtures that play a critical role in the timely and successful completion of oil and gas wells. In the particular case of offshore operations, proper design of drilling fluids is of paramount importance in the constant quest to lower break-even prices. Most downhole problems are directly or in-directly related to the rheological and physical properties of drilling fluids, thereby calling for a better understanding of the underlying changes of these properties with respect to drilling fluid composition and external conditions.

The current stance in the design of drilling fluids involves the selection of components and their …

Application Of Active And Edible Films Of Sodium Caseinate To Extend The Shelf-Life Of Argentine Pategrás Cheese, Brenda S. Álvarez, Natalia Damiani, Marina Czerner, Josefa F. Martucci, Liesel B. Gende

Journal of Applied Packaging Research

Argentine Pategrás cheese is one of the most popular types of cheese in Argentina. The main spoilage causes in these products are microbiological contamination and lipid rancidity. Semi-hard cheeses are usually covered with a paraffin wax that favors its preservation. When pieces are stored, cutting faces must be protected to prevent desiccation and contamination. Active biodegradable films are an alternative to the traditional materials, in particular, casein-based edible films are attractive for food applications. In the present work, active films of sodium caseinate with oregano (Origanum vulgare) and laurel (Laurus nobilis) essential oils were produced for …

2019 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

The Fall 2019 ENGR333 project focused on the energy rebound effect.

I asked the students “How much energy does energy efficiency save?”

This project resulted in a working paper and two journal articles submitted to The Energy Journal. The journal articles remain under review as of October 2023.

Customer

The customer for this project was Dr. Paul E. Brockway, University of Leeds, UK.

A Test-Bed For Measuring Uas Servo Reliability, Abdelrahman Elsaid, Daniel Kwasi Adjekum, John Nordlie, Fatima El Jamiy

Aviation Faculty Publications

Extant literature suggests minimal research on the reliability of Commercial off-the-shelf (COTS) components used in fabricating non-military Unmanned Aerial System (UAS). Stochastic failures of components during operational cycles over time poses a safety hazard to flight operations. The purpose of the study was to critically assess the operational performance standards (reliability) of a laboratory designed UAS component test-bed operated using real-world data collected from a Boeing Scan Eagle^® UAS aileron servo unit via a flight data recorder. The study hypothesized that the test-bed’s reliability, in terms of a measured encoder output of commanded servo positions, will not be significantly …

Competitive Strategies In Small And Medium Sized Enterprises (Sme's): A Cross- Case Analysis Of Irish Construction Professional Service Firms, Oluwasegun O. Seriki, Roisin Murphy

Conference papers

Strategy formulation aims to attain strategic fit between an organisation and its business environment in pursuit of competitive advantage. Although competitive strategy research is long established within industries such as manufacturing, financial services and IT, strategy within construction is still under-investigated by comparison. For construction professional service firms (CPSFs), the dearth of academic inquiry is even more apparent, partly due to the intangible nature of their service offerings, highly customised nature of their services and reliance on intellectual capital. The Irish construction sector is experiencing stable growth since following a prolonged recession, thus understanding the strategy process within professional service …

Design And Analysis Of Tunable Non-Touching Lattices With Optical Bandgap Control, Tamal Sarkar

Student Theses and Dissertations

Interaction between the electromagnetic field and binary charged particles in altered dielectric systems has received interest in recent research endeavors in the field of optical and electromagnetic manipulation. Micro-level interactive forces among charged particles create electrostatic stability in the particle assembly in the altered dielectric system, which leads to a lattice structure that constitutes spacing. Under external field excitation, multiple particle configurations tend to show a considerable change in particle position at microscale that features the electromagnetic tunability of non-touching lattices. In addition to the tunable features, the multiple charged dielectric particle configurations in the inverted dielectric system offer optical …

A Study Of Onboarding And Turnover Mediating Variables In U.S. Air Force Officers, Brett S. Bowers

Theses and Dissertations

Employee retention, while always a concern in the workplace, has become a greater challenge for organizations in recent years. Today’s working class has displayed a propensity to change jobs more rapidly than previous generations, exacerbating not only turnover rates but also the costs associated with them (Frankel, 2016). This challenge is especially relevant to the United States Air Force, which has experienced difficulty retaining young officers in recent years. The problems resulting from this voluntary turnover are exceedingly impactful to the military command structure, as senior leaders must work their way up from the lowest ranks. As such, the Air …

Pipelined Parallelism In A Work-Stealing Scheduler, Thomas Kelly

All Computer Science and Engineering Research

A pipeline is a particular type of parallel program structure, often used to represent loops with cross-iteration dependencies. Pipelines cannot be expressed with the typical parallel language constructs offered by most environments. Therefore, in order to run pipelines, it is necessary to write a parallel language and scheduler with specialized support for them. Some such schedulers are written exclusively for pipelines and unable to run any other type of program, which allows for certain optimizations that take advantage of the pipeline structure. Other schedulers implement support for pipelines on top of a general-purpose scheduling algorithm. One example of such an …

Enhanced Crystallinity Of Triple-Cation Perovskite Film Via Doping Nh4Scn, Ziji Liu, Detao Liu, Hao Chen, Long Ji, Hualin Zheng, Yiding Gu, Feng Wang, Zhi Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

The trap-state density in perovskite films largely determines the photovoltaic performance of perovskite solar cells (PSCs). Increasing the crystal grain size in perovskite films is an effective method to reduce the trap-state density. Here, we have added NH₄SCN into perovskite precursor solution to obtain perovskite films with an increased crystal grain size. The perovskite with increased crystal grain size shows a much lower trap-state density compared with reference perovskite films, resulting in an improved photovoltaic performance in PSCs. The champion photovoltaic device has achieved a power conversion efficiency of 19.36%. The proposed method may also impact other optoelectronic …

Assessing The Origin Of Noise In The Precipitation Gauge Geonor T-200b, Jonah B. Basl, Scott Landolt, Justin Lentz

STAR Program Research Presentations

The Geonor T-200B is an all-weather precipitation gauge utilized by the Research Applications Laboratory (RAL) under the University Corporation for Atmospheric Research (UCAR) and the National Center for Atmospheric Research (NCAR). RAL has been dealing with a persistent issue of noise within the Geonor Devices during non-precipitation events. When there is not precipitation occurring, the data reading off the Geonor would be expected to be a constant value, as no precipitation is being collected. However, the device is producing unaccounted variation (noise) causing tremor like lines to appear in the data. The noise in the data is an issue for …

Structures, Properties, And Applications Of Cnt-Graphene Heterostructures, Wei Du, Zubair Ahmed, Qi Wang, Cui Yu, Zhihong Feng, Guoyuan Li, Min Zhang, Changjian Zhou, Richard Senegor, Cary Y. Yang

Electrical and Computer Engineering

Both carbon nanotube (CNT) and graphene exhibit excellent properties and have many potential applications in integrated circuits, composite materials, thermal management, sensors, energy storage, and flexible electronics. However, their superior properties are confined to one or two dimensions, thus limiting their utility in interconnects or thermal interface materials that require a 3D structure for efficient electron and/or phonon transport. It is conceivable that a combined CNT-graphene structure would provide new opportunities for realizable applications in these and other fields. In recent years, numerous results on synthesis, structural analyses, theoretical modeling, and potential applications of various CNT-graphene heterostructures have been reported. …

Long-Term Changes Of Open-Surface Water Bodies In The Yangtze River Basin Based On The Google Earth Engine Cloud Platform, Yue Deng, Wei-Guo Jiang, Zhenghong Tang, Ziyan Ling, Zhifeng Wu

Community and Regional Planning Program: Faculty Scholarly and Creative Activity

The spatiotemporal changes of open-surface water bodies in the Yangtze River Basin (YRB) have profound influences on sustainable economic development, and are also closely relevant to water scarcity in China. However, long-term changes of open-surface water bodies in the YRB have remained poorly characterized. Taking advantage of the Google Earth Engine (GEE) cloud platform, this study processed 75,593 scenes of Landsat images to investigate the long-term changes of open-surface water bodies in the YRB from 1984 to 2018. In this study, we adopted the percentile-based image composite method to collect training samples and proposed a multiple index water detection rule …

Illuminator, Volume 3, Issue 1, Batten College Of Engineering & Technology, Old Dominion University

College of Engineering & Technology Newsletter

September 2019 issue of Illuminator, a monthly publication of ODU's Batten College of Engineering and Technology.

Axial-Field Vernier-Type Flux Modulation Machines For Low-Speed Direct-Drive Applications, Vandana Rallabandi, Peng Han, Murat G. Kesgin, Narges Taran, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper proposes different configurations of axial-field machines featuring a very large ratio of the number of rotor poles to stator teeth and coils suitable for low-speed direct-drive traction applications. The machines have a single rotor with spoke-type permanent magnets and the stator teeth include auxiliary slots, the function of which is to enhance the high-polarity component of the stator magnetomotive force interacting with the rotor to produce a net torque. The machines can be constructed with three or two phases, in which case they inherently exhibit high tolerance to faults due to the combined effect of a lack of …

Structure And Reactivity Of Single Site Ti Catalysts For Propylene Epoxidation, Zheng Lu, Xiaoyang Liu, Bin Zhang, Zhuoran Gan, Siwen Tang, Lu Ma, Tianpin Wu, George J. Nelson, Yong Qin, Heath C. Turner, Yu Lei

PRC-Affiliated Research

Propylene epoxidation using molecular oxygen and hydrogen mixture on Au-based catalysts has attracted attention because of high propylene oxide selectivity and the use of an inexpensive and environmental friendly oxidant. Single-site titanium on metal oxide supports plays an important role in achieving high reactivity and selectivity in propylene epoxidation. Here we used TiO2 atomic layer deposition (ALD) to synthesize single-site titanium imbedded in the SiO2 framework for propylene epoxidation. High temperature calcination was used as post-treatment to control the titania structure and Tisingle bondO coordination number. Using UV–vis spectroscopy and X-ray absorption spectroscopy, we successfully established that under similar propylene …

Mnews: A Study Of Multilingual News Search Interfaces, Chenjun Ling

Engineering Ph.D. Theses

With the global expansion of the Internet and the World Wide Web, users are becoming increasingly diverse, particularly in terms of languages. In fact, the number of polyglot Web users across the globe has increased dramatically.

However, even such multilingual users often continue to suffer from unbalanced and fragmented news information, as traditional news access systems seldom allow users to simultaneously search for and/or compare news in different languages, even though prior research results have shown that multilingual users make significant use of each of their languages when searching for information online.

Relatively little human-centered research has been conducted to …

On The Control Of A Solid State Transformer For Multi-Mw Utility-Scale Pv-Battery Systems, Yibin Zhang, Oluwaseun M. Akeyo, Jiangbiao He, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

The utility-scale photovoltaic (PV)-battery systems typically include multiple power converters connected to the grid via traditional line frequency transformers (LFT), which may be considered bulky, and inefficient when compared with the emerging solid state transformers (SST). This paper proposes a SST with power and voltage controls for utility-scale PV-battery systems. The PV system was modeled based on available data from a universal solar facility located in Kentucky, USA. Furthermore, this paper provides detailed controller designs for the proposed utility-scale PV-battery system based on a SST which includes: the PV-side dual-active bridge (DAB) converter tracks the maximum power point, the PV …

Communication Theory, Yi Sun

Open Educational Resources

No abstract provided.

Aircraft Hydraulic Systems - Fundamentals, Nihad E. Daidzic

Aviation Department Publications

Aircraft hydraulic systems are essential non-propulsive power systems. Hydraulic power systems are used to power major functional aircraft systems, such as flight controls (primary and secondary), friction braking, nose gear steering, thrust-reversers, operating heavy cargo doors, etc.

A Hybrid Analytical And Fe-Based Method For Calculating Ac Eddy Current Winding Losses Taking 3d Effects Into Account, Narges Taran, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper proposes a new hybrid analytical and numerical FE-based method for calculating ac eddy current losses in wire windings and demonstrates its applicability for axial flux electric machines. The method takes into account 3D field effects in order to achieve accurate results and yet greatly reduce computational efforts. It is also shown that hybrid methods based on 2D FE models, which require semi-empirical correction factors, may over-estimate the eddy current losses. The new 3D FE-based method is advantageous as it employs minimum simplifications and considers the end turns in the eddy current path, the magnetic flux density variation along …