Digital Commons Network^™

A Convenient Miniature Test Platform For Polyelectrolyte Membrane Fuel-Cell Research, Jamie A. Shetzline, Saheed Bukola, Stephen E. Creager

Publications

A simple and convenient small-scale fuel-cell test platform was created from a commercial compression fitting and graphite rod current collectors and used to conduct diagnostic tests on disk-shaped membrane-electrode assemblies (MEAs) fabricated from Nafion membranes and Nafion-impregnated platinum-on-carbon-cloth anodes and cathodes. A key advantage of this test platform is that it requires very little material, perhaps just a few milligrams, to conduct a fuel-cell test on a supported catalyst. Electrochemically-active surface area (ECSA) values for supported platinum on carbon-cloth electrodes were obtained by in-situ(in the fuel cell) and ex-situ (in liquid electrolyte) cyclic voltammetry on similarly-prepared electrodes, and values …

A Revision Of Prespelea Park (Staphylinidae, Pselaphinae), Michael S. Caterino, Laura M. Vásquez-Vélez

Publications

We revise the genus Prespelea Park, redefining and redescribing the two previously known species, P.copelandi Park and P. quirsfeldi Park, and adding ten new species: P. parki Caterino & Vásquez-Vélez, sp. n., P.minima Caterino & Vásquez-Vélez, sp. n., P. morsei Caterino & Vásquez-Vélez, sp. n., P. divergens Caterino & Vásquez-Vélez, sp. n., P. carltoni Caterino & Vásquez-Vélez, sp. n., P. myersae Caterino & Vásquez-Vélez, sp. n., P. georgiensis Caterino & Vásquez-Vélez, sp. n., P. enigma Caterino & Vásquez-Vélez, sp. n., P. wagneriCaterino & Vásquez-Vélez, sp. n., and P. basalis Caterino …

Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears

Publications

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel …

Real-Time Traffic State Estimation With Connected Vehicles, Sakib Mahmud Khan, Kaken Dey, Mashrur Chowdhury

Publications

A novel framework is developed in this paper, to increase the real-time roadway traffic condition assessment accuracy, which integrates connected vehicle technology (CVT) with artificial intelligence (AI) paradigm forming a CVT-AI method. Traffic density is a major indicator of traffic conditions. In this paper, the traffic operational condition is assessed based on traffic density. A simulated network of Interstate 26 in South Carolina is developed to investigate the effectiveness of the method. The assumption is that the vehicle onboard units will forward the CV generated data to the edge devices (e.g., roadside units) for further processing. CV generated distance headway …

Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears

Publications

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel …

Is It Engineering Or Not?, Brooke A. Whitworth, Lindsay B. Wheeler

Publications

With the widespread adoption of the Next Generation Science Standards (NGSS Lead States 2013), science teachers now aspire to integrate engineering into science instruction, as the standards suggest, yet many don’t know how. The first steps are to define engineering and identify tasks that incorporate engineering, which can be difficult and confusing. This article presents a simple explanation of engineering and offers a framework to help teachers determine whether a task is based on engineering. We also offer examples of how to integrate engineering in Earth science, chemistry, biology, and physics.

Quality Function Deployment And Proactive Quality Techniques Applied To University Lectures To Improve Student Feedback, Kenneth Witcher, Elena Navarro, Beverly Wood, Ian Mcandrew

Publications

Lecturing and instruction to students at university has traditionally been based on qualifications, experience and position of academics within ones department or college. The higher the level and more advanced the subject then the most experienced lecturers are traditionally selected for that task. Visiting lecturers are never asked to teach basic mathematics or science, they are to share their experience and enlighten the students from a vast knowledge and history. This paper reviews and discusses Kano’s model with Quality Function Deployment related to customer satisfaction and compares if the traditional approach is in keeping with university practice. Furthermore, it argues …

Creating An Experimental Learning And Research Driven Spacesuit Lab For Erau, Ryan L. Kobrick, Erik Seedhouse

Publications

This paper evaluates key functional data parameters that must be considered for suborbital spaceflight participants wearing pressurized suits for intravehicular activity (IVA). Data parameters of an analog spacesuit worn in an analog flight environment were obtained from 40 civilian participants using the Suborbital Space Flight Simulator (SSFS) at Embry-Riddle Aeronautical University (ERAU) while donning Final Frontier Design’s (FFD) fully pressurized third-generation spacesuit as part of their training for Project PoSSUM (the Polar Suborbital Science in the Upper Mesosphere Project). The physiological data collected included: blood pressure, electrocardiograms, heart rate, grip strength, and skin temperature. These parameters were measured using a …

Osh Certifications: Behind The Exams, Cheryl (Cheri) L. Marcham, Treasa M. Turnbeaugh, Nicola J. Wright

Publications

• The process for developing and scoring a certification exam is complicated and uses a scientific and mathematical psychometric process to achieve defendable outcomes.

• However, how much of the process is well understood by either the general public, employers or even safety and health professionals?

• The information presented is intended to help the safety and health professional understand why and how a properly developed and administered certification exam shows the mark of excellence in the field of safety and health.

Multi-Choice Questions And Their Problems When Used For Assessment Of Aircraft Engineers Education, Ian R. Mcandrew, Ken L. Witcher, Elena Navarro, Peter Foreman

Publications

Licensed aircraft engineers under the European Aviation Safety Agency, EASA, undertake academic training to complement their practical and type specific studies. These exams are mainly Multi-Choice Questions, MCQ, and four 20-minute essays. The MCQ exams are as few as 16 questions to a maximum of 140 questions. A score of 75% is needed to pass each exam, and each question has three possible answers. This authors of this paper reviews the theory and design of the MCQ and asks if the assumptions are valid and that it achieves the academic level assumed for engineers who will be maintaining some of …

Local Time Asymmetry Of Saturn's Magnetosheath Flows, B. Burkholder, P. A. Delamere, X. Ma, M. F. Thomsen, R. J. Wilson, F. Bagenal

Publications

Using gross averages of the azimuthal component of flow in Saturn's magnetosheath, we find that flows in the prenoon sector reach a maximum value of roughly half that of the postnoon side. Corotational magnetodisc plasma creates a much larger flow shear with solar wind plasma prenoon than postnoon. Maxwell stress tensor analysis shows that momentum can be transferred out of the magnetosphere along tangential field lines if a normal component to the boundary is present, i.e., field lines which pierce the magnetopause. A Kelvin‐Helmholtz unstable flow gives rise to precisely this situation, as intermittent reconnection allows the magnetic field to …

Sedentary Behavior Research Network (Sbrn) - Terminology Consensus Project Process And Outcome, Mark S. Tremblay, Salomé Aubert, Joel D. Barnes, Travis J. Saunders, Valerie Carson, Amy E. Latimer-Cheung, Sebastien F.M. Chastin, Teatske M. Altenburg, Mai J.M. Chinapaw, Saeideh Aminian, Lauren Arundell, Trina Hinkley, Jill Hnatiuk, Andrew J. Atkin, Kevin Belanger, Jean Philippe Chaput, Katie Gunnell, Richard Larouche, Taru Manyanga, Bethany Barone Gibbs, Rebecca Bassett-Gunter, Stuart Biddle, Aviroop Biswas, Josephine Chau, Rachel Colley, Tara Coppinger, Catharine Craven, Carlos Cristi-Montero, Douglas De Assis Teles Santos, Borja Del Pozo Cruz, Jesus Del Pozo-Cruz, Paddy Dempsey

Publications

Background: The prominence of sedentary behavior research in health science has grown rapidly. With this growth there is increasing urgency for clear, common and accepted terminology and definitions. Such standardization is difficult to achieve, especially across multi-disciplinary researchers, practitioners, and industries. The Sedentary Behavior Research Network (SBRN) undertook a Terminology Consensus Project to address this need. Method: First, a literature review was completed to identify key terms in sedentary behavior research. These key terms were then reviewed and modified by a Steering Committee formed by SBRN. Next, SBRN members were invited to contribute to this project and interested participants reviewed …

Traveling Wave Solutions To Kawahara And Related Equations, S.C. Mancas

Publications

Traveling wave solutions to Kawahara equation (KE), transmission line (TL), and Korteweg-de Vries (KdV) equation are found by using an elliptic function method which is more general than the tanh-method. The method works by assuming that a polynomial ansatz satisfies a Weierstrass equation, and has two advantages: first, it reduces the number of terms in the ansatz by an order of two, and second, it uses Weierstrass functions which satisfy an elliptic equation for the dependent variable instead of the hyperbolic tangent functions which only satisfy the Riccati equation with constant coefficients. When the polynomial ansatz in the traveling wave …

First Na Lidar Measurements Of Turbulence Heat Flux, Thermal Diffusivity, And Energy Dissipation Rate In The Mesopause Region, Yafang Guo, Alan Z. Liu, Chester S. Gardner

Publications

Turbulence is ubiquitous in the mesopause region, where the atmospheric stability is low and wave breaking is frequent. Measuring turbulence is challenging in this region and is traditionally done by rocket soundings and radars. In this work, we show for the first time that the modern Na wind/temperature lidar located at Andes Lidar Observatory in Cerro Pachón, Chile, is able to directly measure the turbulence perturbations in temperature and vertical wind between 85 and 100 km. Using 150 h of lidar observations, we derived the frequency (ω) and vertical wave number (m) spectra for both gravity …

Gw170104: Observation Of A 50-Solar-Mass Binary Black Hole Coalescence At Redshift 0.2, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, B. Hughey, J. W. W. Pratt, E. Schmidt, G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.

Publications

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2 þ8.4 −6.0M⊙ and 19.4 þ5.3 −5.9M⊙ (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, …

A Grounded Qualitative Analysis Of The Effect Of A Focus Group On Design Process In A Virtual Internship, Matthew R. Markovetz, Sean Sullivan, Renee M. Clark, Zachari Swiecki, Golnaz Arastoopour Irgens, David W. Shaffer, Naomi C. Chesler, Cheryl A. Bodnar

Publications

A key component associated with the development of an entrepreneurial mindset is the ability to understand customerneeds and consider this when developing a product. This study sought to understand whether the inclusion of a customerfocus group as part of a virtual internship created any differences in the design processes of sophomore engineeringstudents (114 students). The Nephrotex virtual internship requires that students design a dialysis membrane by optimizinga selection of four components: membrane polymer, polymerization process, processing surfactant, and carbon nanotubepercentage. We found that sophomores who engaged in a focus group during the virtual internship Nephrotex showed(statistically) equal focus on cost …

Data‐Enabled Cognitive Modeling: Validating Student Engineers’ Fuzzy Design‐Based Decision‐Making In A Virtual Design Problem, Golnaz Arastoopour Irgens, Naomi C. Chesler, Jeffrey Linderoth, David Williamson Shaffer

Publications

The ability of future engineering professionals to solve complex real‐world problems depends on their design education and training. Because engineers engage with open‐ended problems in which there are unknown parameters and multiple competing objectives, they engage in fuzzy decision‐making, a method of making decisions that takes into account inherent imprecisions and uncertainties in the real world. In the design‐based decision‐making field, few studies have applied fuzzy decision‐making models to actual decision‐making process data. Thus, in this study, we use datasets on student decision‐making processes to validate approximate fuzzy models of student decision‐making, which we call data‐enabled cognitive modeling. The results …

Electromagnetic Radio Frequency Heating In The Pulsed Electric Current Sintering (Pecs) Process, Yufei Liu, D. H. Liebenberg

Publications

Pulsed electric current sintering offers rapid sintering of many materials compared with hot press sintering. Earlier studies had demonstrated that neither sparks nor plasma formation occur in a typical apparatus such as Dr. Sinter™. Hitchcock et al. showed that electromagnetic radio frequency (rf) emission occurred during the pulsing current and suggested this emission was a relevant augmentation to the hot press sintering in addition to the current flow in the specimen. In this report the importance of rf emission in the sintering process is demonstrated and opportunities to further exploit this approach to improve the sintering process are suggested.

The Soil Moisture Velocity Equation, Fred L. Ogden, Myron B. Allen, Wencong Lai, Jianting Zhu, Mookwon Seo, Craig C. Douglas, Cary A. Talbot

Publications

Numerical solution of the one-dimensional Richards' equation is the recommended method for coupling groundwater to the atmosphere through the vadose zone in hyperresolution Earth system models, but requires fine spatial discretization, is computationally expensive, and may not converge due to mathematical degeneracy or when sharp wetting fronts occur. We transformed the one-dimensional Richards' equation into a new equation that describes the velocity of moisture content values in an unsaturated soil under the actions of capillarity and gravity. We call this new equation the Soil Moisture Velocity Equation (SMVE). The SMVE consists of two terms: an advection-like term that accounts for …

The Influence Of Exurban Landscapes And Local Site Characteristics On Riparian Vegetation, Nathan Weaver, Kyle Barrett, Don L. Hagan

Publications

The southern Appalachian Mountains have experienced large population growth and a change in land use in the past 30 years. The majority of development has been low density, suburban land, known as exurban development. The long-term effects of exurbanization on riparian vegetative communities in the southeastern Appalachian Mountains are not well known. We sought to determine if vegetative community composition and structure change as a function of watershed–level variables such as time since neighborhood development or percent impervious surface within the watershed. We also assessed local–scale measures of disturbance such as canopy cover and basal area. Over two years we …

Influence Of Activated Carbon Surface Oxygen Functionality On Elemental Mercury Adsorption From Aqueous Solution, Emily K. Faulconer, David W. Mazyck

Publications

Mercury (Hg), though naturally occurring, is a toxic element. Exposure to various forms of mercury can be harmful for humans and ecosystems. Mercury-contaminated wastewater can be treated using activated carbon to adsorb the mercury, allowing for safe discharge. Wet chemical oxidation of activated carbon was performed to enhanced surface oxygen functionality, with the objective of enhancing aqueous ionic (Hg(II)) and elemental (Hg(0)) mercury adsorption. Characterization of the modified carbons included nitrogen adsorption-desorption, elemental analysis, point of zero charge, and total acidity titration. The concentration and identity of the modifying reagent influenced the characteristics of the carbons, including the surface oxygen …

Book Review: Shoot The Moon: A Complete Guide To Lunar Imaging, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Shoot the Moon: a Complete Guide to Lunar Imaging by Dupont-Bloch, Nicolas. Cambridge, 2016, 323 p index, 9781107548442 $39.95, 9781316657867 $32.00.

Search For Gravitational Waves Associated With Gamma-Ray Bursts During The First Advanced Ligo Observing Run And Implications For The Origin Of Grb 150906b, B. P. Abbott, K. Gill, B. Hughey, J. W. W. Pratt, E. Rhoades, E. Schmidt, S. G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.

Publications

We present the results of the search for gravitational waves (GWs) associated with γ-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 γ-ray bursts for which LIGO data are available with sufficient duration. For all γ-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of ${10}^{-2}{M}_{\odot }{c}^{2}$ were emitted within the $16$–$500$ Hz band, and we find a median 90% confidence limit of 71 Mpc at 150 Hz. …

Temperature Variations In The Dayside Magnetosheath And Their Dependence On Ion-Scale Magnetic Structures: Themis Statistics And Measurements By Mms, A. P. Dimmock, A. Osmane, T. I. Pulkkinen, K. Nykyri, E. Kilpua

Publications

The magnetosheath contains an array of waves, instabilities, and nonlinear magnetic structures which modify global plasma properties by means of various wave-particle interactions. The present work demonstrates that ion-scale magnetic field structures (∼0.2–0.5 Hz) observed in the dayside magnetosheath are statistically correlated to ion temperature changes on orders 10–20% of the background value. In addition, our statistical analysis implies that larger temperature changes are in equipartition to larger amplitude magnetic structures. This effect was more pronounced behind the quasi-parallel bow shock and during faster solar wind speeds. The study of two separate intervals suggests that this effect can result from …

Exchange Of Polar Lipids From Adults To Neonates In Daphnia Magna: Perturbations In Sphingomyelin Allocation By Dietary Lipids And Environmental Toxicants, Namrata Sengupta, Delaney C. Reardon, Patrick D. Gerard, William S. Baldwin

Publications

Because xenosensing nuclear receptors are also lipid sensors that regulate lipid allocation, we hypothesized that toxicant-induced modulation of HR96 activity would alter lipid profiles and the balance between adult survival and neonate production following exposure in Daphnia magna. Adult daphnids were exposed to unsaturated fatty acid- and toxicant- activators or inhibitors of HR96 and later starved to test whether chemical exposure altered allocation toward survival or reproduction. The HR96 activators, linoleic acid and atrazine, decreased reproduction as expected with concomitant changes in the expression of HR96 regulated genes such as magro. The HR96 inhibitors, docosahexaenoic acid (DHA) and triclosan, …

Moliere: Automatic Biomedical Hypothesis Generation System, Justin Sybrandt, Michael Shtutman, Ilya Safro

Publications

Hypothesis generation is becoming a crucial time-saving technique which allows biomedical researchers to quickly discover implicit connections between important concepts. Typically, these systems operate on domain-specific fractions of public medical data. MOLIERE, in contrast, utilizes information from over 24.5 million documents. At the heart of our approach lies a multi-modal and multi-relational network of biomedical objects extracted from several heterogeneous datasets from the National Center for Biotechnology Information (NCBI). These objects include but are not limited to scientific papers, keywords, genes, proteins, diseases, and diagnoses. We model hypotheses using Latent Dirichlet Allocation applied on abstracts found near shortest paths discovered …

Random Access In Nondelimited Variable-Length Record Collections For Parallel Reading With Hadoop, Jason Anderson, Christopher Gropp, Linh Ngo, Amy W. Apon

Publications

The industry standard Packet CAPture (PCAP) format for storing network packet traces is normally only readable in serial due to its lack of delimiters, indexing, or blocking. This presents a challenge for parallel analysis of large networks, where packet traces can be many gigabytes in size. In this work we present RAPCAP, a novel method for random access into variable-length record collections like PCAP by identifying a record boundary within a small number of bytes of the access point. Unlike related heuristic methods that can limit scalability with a nonzero probability of error, the new method offers a correctness guarantee …

Effects Of Protein Corona On Iapp Amyloid Aggregation, Fibril Remodelling, And Cytotoxicity, Emily H. Pilkington, Yanting Xing, Bo Wang, Aleksandr Kakinen, Miaoyi Wang, Thomas P. Davis, Feng Ding, Pu Chen Ke

Publications

Aggregation of islet amyloid polypeptide (IAPP), a peptide hormone co-synthesized and co-stored with insulin in pancreatic cells and also co-secreted to the circulation, is associated with beta-cell death in type-2 diabetes (T2D). In T2D patients IAPP is found aggregating in the extracellular space of the islets of Langerhans. Although the physiological environments of these intra- and extra-cellular compartments and vascular systems significantly differ, the presence of proteins is ubiquitous but the effects of protein binding on IAPP aggregation are largely unknown. Here we examined the binding of freshly-dissolved IAPP as well as pre-formed fibrils with two homologous proteins, namely cationic …

A Spreadsheet For Estimating Soil Water Characteristic Curves (Swcc), Ghada Ellithy

Publications

SWCC can be measured in the lab; however, due to the cost, time, and high variability in the results, empirical equations were developed using multiple regression approaches on databases consisting of a large number of measured SWCCs. The spreadsheet presented herein utilizes different methods that use basic soil properties, such as grain size distribution and Atterberg limits, to calculate the input parameters for van Genuchten and Fredlund and Xing equations. These parameters are required by numerical models, such as SEEP/W, to perform transient seepage analysis. The spreadsheet allows copying the generated curve data points as well as an input into …

Imf Dependence Of Energetic Oxygen And Hydrogen Ion Distributions In The Near-Earth Magnetosphere, H. Luo, E. A. Kronberg, K. Nykyri, K. J. Trattner, P. W. Daly, G. X. Chen, A. M. Du, Y. S. Ge

Publications

Energetic ion distributions in the near-Earth plasma sheet can provide important information for understanding the entry of ions into the magnetosphere and their transportation, acceleration, and losses in the near-Earth region. In this study, 11 years of energetic proton and oxygen observations (> ~274 keV) from Cluster/Research with Adaptive Particle Imaging Detectors were used to statistically study the energetic ion distributions in the near-Earth region. The dawn-dusk asymmetries of the distributions in three different regions (dayside magnetosphere, near-Earth nightside plasma sheet, and tail plasma sheet) are examined in Northern and Southern Hemispheres. The results show that the energetic ion distributions …