Engineering Commons^™

Method And System For Optimal Coordination Control And Soft Repair Of Multiple Rooftop Heating And Cooling Units, Haorong Li

Durham School of Architectural Engineering and Construction: Faculty Publications

Techniques are described that may be implemented in an adaptive control device to regulate multiple zone environmental units based upon multiple temperature values and multiple airflow values, where each temperature value and each airflow value is related to the temperature and the airflow in a specific zone. In an implementation, the input interface of the adaptive control device is configured to receive multiple temperature values and multiple air flow values from multiple zone sensors. The adaptive control device may calculate multiple operational values based on the multiple temperature values and the multiple air flow values. An operational value indicates a …

Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu

School of Natural Resources: Faculty Publications

Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared. Landsat 8 extends the remarkable 40 year Landsat record and has enhanced capabilities including new spectral bands in the blue and cirrus cloud-detection portion of the spectrum, two thermal bands, improved sensor signal-to-noise performance and associated improvements in radiometric resolution, and an improved duty cycle that allows collection of a significantly greater number of images per day. This paper introduces the current (2012–2017) Landsat Science Team's efforts to establish an initial understanding of …

Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton

School of Natural Resources: Faculty Publications

Photosynthesis (PSN) is a pigment level process in which antenna pigments (predominately chlorophylls) in chloroplasts absorb photosynthetically active radiation (PAR) for the photochemical process. PAR absorbed by foliar non-photosynthetic components is not used for PSN. The fraction of PAR absorbed (fAPAR) by a canopy/vegetation (i.e., fAPAR_canopy) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) images, referred to as MOD15A2 FPAR, has been used to compute absorbed PAR (APAR) for PSN (APAR_PSN) which is utilized to produce the standard MODIS gross primary production (GPP) product, referred to as MOD17A2 GPP. In this study, the fraction of PAR …

Water Metrics, Lisa-Maria Rebelo, Jean-Marc Faurès, Poolad Karimi, Wim Bastiaanssen, Meredith Giordano, Vladimir Smakhtin, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

Society has a universal need for water that crosses all sectors of activity. We need to be able to measure progress towards sustainable water for all by working towards targets that consider the different dimensions of water resources and use, including water quantity and quality. A suite of indicators that reflect water use by different sectors is needed to measure progress towards the forthcoming SDGs’ [sustainable development goals] water-related targets. Such indicators will need to rely on national data, must consider the variation in data availability, and can be complemented with new cost-effective ways for data collection.

Remote sensing measurements, …

Water-Food-Energy Nexus, Jeremy Bird, Felix Dodds, Peter G. Mccornick, Tushaar Shah

Daugherty Water for Food Global Institute: Faculty Publications

The proposed SDGs on water, food and energy security all include targets on increasing efficiencies. Yet the water–food–energy nexus has multiple dimensions that, if managed in isolation, will compromise a nation’s ability to achieve the full portfolio of SDGs.

Climate change introduces additional uncertainties, further increasing tensions between sectors for access to water. Conventional energy and food production are emitters of greenhouse gases, but measures to reduce emissions—including renewable energy interventions, such as subsidies for biofuel production—can have adverse consequences on food prices.

To achieve desirable and sustainable outcomes for water, food, and energy requires investigating these elements as an …

Afrontar El Cambio: Cuidar Del Agua, De La Agricultura Y De La Seguridad Alimentaria En Una Era De Incertidumbre Climática, Peter G. Mccornick, Vladimir Smakhtin, Luna Bharati, Robyn Johnston, Matthew Mccartney, Fraser Sugden, Floriane Clement, Beverly Mcintyre

Daugherty Water for Food Global Institute: Faculty Publications

En 1950, la población mundial era apenas superior a los 2500 millones de habitantes. En 2013, ronda los 7 mil millones. Aunque el crecimiento de la población se está ralentizando, se estima que en 2050 se alcanzarán los 9600 millones de habitantes. El aumento de la población será mayor en los países en desarrollo, donde los alimentos a menudo escasean, y la tierra y el agua están sometidas a presión. Para alimentar a la población mundial en 2050, tendrán que producirse más alimentos sin que haya un aumento significativo del terreno de cultivo y contando con un caudal menor de …

Fluoride Exposure From Groundwater As Reflected By Urinary Fluoride And Children’S Dental Fluorosis In The Main Ethiopian Rift Valley, Tewodros Rango, Avner Vengosh, Marc Jeuland, Redda Tekle-Haimanot, Erika Weinthal, Julia Kravchenko, Christopher Paul, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are lifelong residents of 33 rural communities in which groundwater concentrations of F⁻ cover a wide range. A subset of 156 children was selected for urinary F⁻ measurements. Our results showed that the mean F⁻ concentrations in groundwater were 8.5 ± 4.1 mg/L (range: 1.1–18 mg/L), while those in urine …

The Effect Of Non-Fluoride Factors On Risk Of Dental Fluorosis: Evidence From Rural Populations Of The Main Ethiopian Rift, Julia Kravchenko, Tewodros Rango, Igor Akushevich, Behailu Atlaw, Peter G. Mccornick, R. Brittany Merola, Christopher Paul, Erika Weinthal, Courtney Harrison, Avner Vengosh, Marc Jeuland

Daugherty Water for Food Global Institute: Faculty Publications

Elevated level of fluoride (F⁻) in drinking water is a well-recognized risk factor of dental fluorosis (DF). While considering optimization of region-specific standards for F⁻, it is reasonable, however, to consider how local diet, water sourcing practices, and non-F⁻ elements in water may be related to health outcomes. In this study, we hypothesized that non-F⁻ elements in groundwater and lifestyle and demographic characteristics may be independent predictors or modifiers of the effects of F⁻ on teeth. Dental examinations were conducted among 1094 inhabitants from 399 randomly selected households of 20 rural communities of …

Fluoride Exposure From Groundwater As Reflected By Urinary Fluoride And Children’S Dental Fluorosis In The Main Ethiopian Rift Valley, Tewodros Rango, Avner Vengosh, Marc Jeuland, Redda Tekle-Haimanot, Erika Weinthal, Julia Kravchenko, Christopher Paul, Paul Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 This cross-sectional study explores the relationships between children’s F⁻ exposure from drinking groundwater and urinary F⁻ concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are lifelong residents of 33 rural communities in which …

Variedades De Sorgos Bmr: Una Alternativa Para Producir Forraje, Instituto Nacional De Innovación Y Transferencia En Tecnología Agropecuaria (Inta-Costa Rica), Roberto Tinoco Mora

INTSORMIL Scientific Publications

Nervadura de color café en variedad de sorgo BMR.

Durante el año 2010, el Instituto Nacional de Innovación y Transferencia en Tecnología Agropecuaria (INTA-Costa Rica), conjuntamente con el Programa Colaborativo y de Apoyo a la Investigación del Sorgo, el Mijo y otros Granos (INTSORMIL, CRSP) ubicado en El Salvador. elaboraron un proyecto de investigación para evaluar la adaptación, producción y valor nutritivo de una colección de 15 variedades de sorgo (Sorghum bicolor) para alimentación animal. Las variedades disponían del gen recesivo denominado BMR, siglas en inglés de "Brown mid rib" que significan "vena café" (Figura 1).

Este gen tiene la …

Acuta Enews January 2014 Vol 43, No. 1

ACUTA Newsletters

In this Issue...

1. Living in a 3D World

3. Your invitation to the Strategic Leadership Forum

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5. Board Report

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8. Check lt Out

Bike Braking Vibration Modelling And Measurement, Rob Redfield

United States Air Force: Publications

Modern bicycle disk-brake systems often induce vibration and noise in bike components such as brake rotors, wheels, and even bike frames. When the vibration or noise are excessive, brake performance can be perceived as unsatisfactory. Previous research incorporating bike frame structural dynamics and brake friction modeling has shown that stick-slip friction is likely the cause of much of this vibration and noise. Bicycle design parameters such as brake friction behavior and bike component structural properties are central in producing and/or sustaining these vibrations. The predicted dynamics of these models has correlated reasonably well with the testing of braking systems. This …

State-Space Representation Of The Unsteady Aerodynamics Of Flapping Flight, Haithem E. Taha, Muhammad R. Hajj, Philip S. Beran

United States Air Force: Publications

A state-space formulation for the aerodynamics of flapping flight is presented. The Duhamel's principle, applied in linear unsteady flows, is extended to non-conventional lift curves to capture the LEV contribution. The aspect ratio effects on the empirical formulae used to predict the static lift due to a stabilized Leading Edge Vortex (LEV) are provided. The unsteady lift due to arbitrary wing motion is generated using the static lift curve. Then, state-space representation for the unsteady lift is derived. The proposed model is validated through a comparison with direct numerical simulations of Navier-Stokes on hovering insects. A comparison with quasi-steady models …

Head Impact Exposure In Male And Female Collegiate Ice Hockey Players, Bethany J. Wilcox, Jonathan G. Beckwith, Richard M. Greenwald, Jeffrey J. Chu, Thomas W. Mcallister, Laura A. Flashman, Arthur C. Maerlender, Ann-Christine Duhaime, Joseph J. Crisco

Department of Psychology: Faculty Publications

The purpose of this study was to quantify head impact exposure (frequency, location and magnitude of head impacts) for individual male and female collegiate ice hockey players and to investigate differences in exposure by sex, player position, session type, and team. Ninety-nine (41 male, 58 female) players were enrolled and 37,411 impacts were recorded over three seasons. Frequency of impacts varied significantly by sex (males: 287 per season, females: 170, p < 0.001) and helmet impact location (p < 0.001) but not by player position (p = 0.088). Head impact frequency also varied by session type; both male and female players sustained more impacts in games than in practices (p < 0.001), however the magnitude of impacts did not differ between session types. There was no difference in 95th percentile peak linear acceleration between sexes (males: 41.6 g, females: 40.8 g), but 95th percentile peak rotational acceleration and HITsp (a composite severity measure) were greater for males than females (4424, 3409 rad/s2, and 25.6, 22.3, respectively). Impacts to the back of the helmet resulted in the greatest 95th percentile peak linear accelerations for males (45.2 g) and females (50.4 g), while impacts to the side and back of the head were associated with the greatest 95th percentile peak rotational accelerations (males: 4719, 4256 rad/sec², females: 3567, 3784 rad/sec², respectively). It has been proposed that reducing an individual’s head impact exposure is a practical approach for reducing the risk of …

Experimental Tools To Study Molecular Recognition Within The Nanoparticle Corona, Markita P. Landry, Sebastian Kruss, Justin T. Nelson, Gili Bisker, Nicole M. Iverson, Nigel F. Reuel, Michael S. Strano

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Advancements in optical nanosensor development have enabled the design of sensors using synthetic molecular recognition elements through a recently developed method called Corona Phase Molecular Recognition (CoPhMoRe). The synthetic sensors resulting from these design principles are highly selective for specific analytes, and demonstrate remarkable stability for use under a variety of conditions. An essential element of nanosensor development hinges on the ability to understand the interface between nanoparticles and the associated corona phase surrounding the nanosensor, an environment outside of the range of traditional characterization tools, such as NMR. This review discusses the need for new strategies and instrumentation to …

Airmen With Mild Traumatic Brain Injury (Mtbi) At Increased Risk For Subsequent Mishaps, Casserly R. Whitehead, Timothy S. Webb, Timothy S. Wells, Kari L. Hunter

United States Air Force: Publications

Background: Little is known regarding long-term performance decrements associated with mild Traumatic Brain Injury (mTBI). The goal of this study was to determine if individuals with an mTBI may be at increased risk for subsequent mishaps. Methods: Cox proportional hazards modeling was utilized to calculate hazard ratios for 518,958 active duty U.S. Air Force service members (Airmen) while controlling for varying lengths of followup and potentially confounding variables. Two non-mTBI comparison groups were used; the second being a subset of the original, both without head injuries two years prior to study entrance. Results: Hazard ratios indicate that the causes of …

Quality And Safety Of Minimally Invasive Surgery: Past, Present, And Future, Bernadette Mccrory, Chad A. Lagrange, M. S. Hallbeck

Department of Mechanical and Materials Engineering: Faculty Publications

Adverse events because of medical errors are a leading cause of death in the United States (US) exceeding the mortality rates of motor vehicle accidents, breast cancer, and AIDS. Improvements can and should be made to reduce the rates of preventable surgical errors because they account for nearly half of all adverse events within hospitals. Although minimally invasive surgery (MIS) has proven patient benefits such as reduced postoperative pain and hospital stay, its operative environment imposes substantial physical and cognitive strain on the surgeon increasing the risk of error. To mitigate errors and protect patients, a multidisciplinary approach is needed …

Measurement Of Hydrodynamic Force Generation By Swimming Dolphins Using Bubble Dpiv, Frank E. Fish, Paul Legac, Terrie M. Williams, Timothy Wei

Department of Mechanical and Materials Engineering: Faculty Publications

Attempts to measure the propulsive forces produced by swimming dolphins have been limited. Previous uses of computational hydrodynamic models and gliding experiments have provided estimates of thrust production by dolphins, but these were indirect tests that relied on various assumptions. The thrust produced by two actively swimming bottlenose dolphins (Tursiops truncatus) was directly measured using digital particle image velocimetry (DPIV). For dolphins swimming in a large outdoor pool, the DPIV method used illuminated microbubbles that were generated in a narrow sheet from a finely porous hose and a compressed air source. The movement of the bubbles was tracked …

Introduction To Special Issue Of Journal Of Defense Modeling And Simulation: Novel Approaches To Defense And Military Modeling And Simulation, Scott D. Snyder, James M. Taylor Jr.

Peter Kiewit Institute: Faculty Publications

Developing solutions to complex problems in government and industry is a daunting task that often requires tremendous investment in time and resources to solve. Modeling and simulation (M&S) has incredible potential to streamline development and cut costs by conducting virtual experiments that give insight into performance under various test conditions. As many program managers in the federal acquisition process can attest, realistic testing of live equipment in an operational environment can be some of the most expensive parts of a development program. M&S can provide insight into mission success of yetto- bedesigned systems without the need to actually build and …

Simple Multi-Attribute Rating Technique For Renewable Energy Deployment Decisions (Smart Redd), James M. Taylor Jr., Betty Love

Peter Kiewit Institute: Faculty Publications

In the effort to provide electrical power service and the sustaining fuel required to run generators at forward-deployed bases in Afghanistan and Iraq over more than 10 years, the United States military spent billions of dollars and a paid a heavy toll in terms of human casualties. The green energy linear program for optimizing deployments (GELPOD) proof-of-concept model showed that a linear program could be used to optimize combat deployment of energy generation systems to minimize cost and casualties. Results indicated that reduction in both cost and casualties for renewable energy sources was highly dependent on fuel cost and deployment …

Phase I Assessment Of Guardrail Length-Of-Need, Francisco Daniel B. Albuquerque, Cody S. Stolle, Dean L. Sicking, Ronald K. Faller, Karla A. Lechtenberg

Mid-America Transportation Center: Final Reports and Technical Briefs

Report No. TRP-03-284-14

Roadside Grading Guidance - Phase Ii, Kevin D. Schrum, Francisco D. B. Albuquerque, Dean L. Sicking, Ronald K. Faller, John D. Reid

Mid-America Transportation Center: Final Reports and Technical Briefs

Phase I of this project relied on assumptions surrounding crash data from the state of Ohio in 2000. The number of fatal and severe crashes in that year was significantly lower than average. As a result, the conclusions were indefinite. Phase II was carried out using crash data from the state of Ohio over seven years. The increased pool of data removed the need for many of the underlying assumptions used in Phase I and provided a solid foundation of conclusions and recommendations.

The number of fatal and severe crashes that occurred on each slope and height for each functional …

Controlled De-Cross-Linking And Disentanglement Of Feather Keratin For Fiber Preparation Via A Novel Process, Helan Xu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Pure protein fibers were fabricated from chicken feathers via a potentially green process. In the last several decades, efforts have been made to produce keratin-based industrial products, especially fibers. However, the methods of producing keratin fibers directly from chicken feathers could not be repeated. In this research, protein fibers from chicken feathers were developed using chemicals that could be either derived from renewable resources or facilely recycled. Backbones of keratin were preserved after cleavage of disulfide bonds using cysteine. Sodium dodecyl sulfate (SDS) was applied to dissolve keratin for spinning. Increasing SDS concentration intensified the ordered conformation of keratin, first …

Fiber-Optic Temperature Sensor Using A Fabry–Pérot Cavity Filled With Gas Of Variable Pressure, Yujie Lu, Ming Han, Jiajun Tian

Department of Electrical and Computer Engineering: Faculty Publications

We report a high-temperature fiber-optic sensor based on measuring the spectral fringes of a Fabry–Pérot (FP) cavity on a microstructure fiber (MF) when the gas pressure in the cavity is varied through the holes in the MF. Theoretical analysis shows that the absolute temperature can be deduced from the slope of the spectral shift versus pressure curve, which requires no calibration and is insensitive to the FP cavity length variations. For demonstration, we fabricated a miniature sensor whose FP cavity is formed by sandwiching a fuse-silica tube between a side-hole MF and a solid-core fiber. Using the holes in the …

An Interconnection And Damping Assignment Passivity-Based Controller For A Dc–Dc Boost Converter With A Constant Power Load, Jianwu Zeng, Zhe Zhang, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an adaptive interconnection and damping assignment (IDA) passivity-based controller (PBC) with a complementary proportional integral (PI) controller for dc–dc boost converters with constant power loads (CPLs). The plant is modeled as a port-controlled Hamiltonian system (PCHS). A virtual circuit that interprets the parameters of the PCHS is then derived to determine the parameters of the IDA-PBC for the system to work in the underdamping, critical-damping, and overdamping modes. Moreover, a complementary PI controller is designed to eliminate the steady-state output voltage error of the IDA-PBC caused by the load variation. Simulation studies are carried out inMATLAB/Simulink to …

An Effective Heat Propagation Path-Based Online Adaptive Thermal Model For Igbt Modules, Ze Wang, Wei Qiao, Bo Tian, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The information of junction temperature is crucial for operation management of IGBT modules. In practice, junction temperature is typically estimated by using an electrothermal model. IGBT modules are subject to various aging processes during operation, some of which, e.g. substrate solder crack, changes the thermal impedance of an IGBT module. However, in the literature little work has included the aging effects into online thermal behavior modeling of IGBT modules. This paper proposes an Effective Heat Propagation Path (EHPP)-based online adaptive thermal model for IGBT modules, where the EHPP is proposed to quantify the impact of substrate solder cracks on the …

An Isolated Multiport Dc–Dc Converter For Simultaneous Power Management Of Multiple Different Renewable Energy Sources, Jianwu Zeng, Wei Qiao, Liyan Qu, Yanping Jiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a new isolated multiport dc–dc converter for simultaneous power management of multiple renewable energy sources, which can be of different types and capacities. The proposed dc–dc converter only uses one controllable switch in each port to which a source is connected. Therefore, it has the advantages of simple topology and minimum number of power switches. A general topology of the proposed converter is first introduced. Its principle and operation are then analyzed. The proposed converter is applied for simultaneous maximum power point tracking (MPPT) control of a wind/solar hybrid generation system consisting of one wind turbine generator …

Evaluation Of Ann Estimation-Based Mppt Control For A Dfig Wind Turbine, Chun Wei, Liyan Qu, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes an artificial neuronal network (ANN) estimation-based wind speed sensolress MPPT algorithm for wind turbines equipped with doubly-fed induction generators (DFIG). The ANN is designed to produce the optimal control signal for the DFIG power or speed controller. The optimal parameters of the ANN are determined by using a particle swarm optimization (PSO) algorithm. A 3.6 MW DFIG wind turbine is simulated in PSCAD to evaluate and compare the proposed MPPT method with the traditional tip speed ratio (TSR) and turbine power profile-based MPPT methods in both the speed control and power control modes in variable wind speed …

A Flux Vector-Based Discrete-Time Direct Torque Control For Salient-Pole Permanent-Magnet Synchronous Generators, Zhe Zhang, Yue Zhao, Jianwu Zeng, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a flux vector-based discretetime direct torque control (DTC) scheme for salient-pole permanent-magnet synchronous generators (PMSGs) used in the variable-speed, direct-drive wind energy conversion systems (WECSs). The discrete-time control law is derived from the perspective of flux space vectors and load angle with the torque and stator flux information only. The saliency of the PMSG is eliminated by the active flux concept. Compared with the existing space vector modulation (SVM)-based DTCs, the proposed scheme removes the use of PI regulators and is less dependent on the machine parameters, e.g., stator inductances and permanent-magnet flux linkage, while maintaining the …

Improved Rotor Position And Speed Estimators For Sensorless Control Of Interior Permanent-Magnet Synchronous Machines, Yue Zhao, Wei Qiao, Long Wu

Department of Electrical and Computer Engineering: Faculty Publications

Model-based rotor position/speed estimators are commonly used for sensorless control of interior permanentmagnet synchronous machines (IPMSMs) operating in the medium- and high-speed regions. A rotor position/speed estimation scheme usually contains three major parts: 1) a state observer; 2) a position estimator; and 3) a speed estimator. This paper proposes a sliding-mode observer (SMO) as the state observer to estimate the position-related system states, which are the extended electromotive force components in this paper. Then, two major contributions are made to achieve improved position and speed estimation. First, the rotor speed is estimated independently using a model reference adaptive system (MRAS)-based …