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2016

Portland State University

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Articles 1 - 30 of 156

Full-Text Articles in Engineering

A Validated Tropical-Extratropical Flood Hazard Assessment For New York Harbor, Philip M. Orton, T. M. Hall, Stefan A. Talke, Alan F. Blumberg, Nickitas Georgas, S. Vinogradov Dec 2016

A Validated Tropical-Extratropical Flood Hazard Assessment For New York Harbor, Philip M. Orton, T. M. Hall, Stefan A. Talke, Alan F. Blumberg, Nickitas Georgas, S. Vinogradov

Civil and Environmental Engineering Faculty Publications and Presentations

Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment …


Webinar: State-Wide Pedestrian And Bicycle Miles Traveled: Can We Estimate It?, Krista Nordback Dec 2016

Webinar: State-Wide Pedestrian And Bicycle Miles Traveled: Can We Estimate It?, Krista Nordback

TREC Webinar Series

Heard of Vehicle Miles Traveled (VMT)? Wouldn’t it be great to know the corresponding value for walking and cycling?

This webinar discusses options for estimating the miles people walk and bicycle on the state-wide level, by investigating the practical considerations of trying to compute these values for one study state.

What strategies can be used, and what data sources do these require?

How do these strategies compare?

How do PMT/BMT estimates vary based on data?

Find out what researchers found and what obstacles they encountered when they tried to estimate bicycle and pedestrian miles traveled in the State of Washington.


A Multi-Agent System For Adaptive Control Of A Flapping-Wing Micro Air Vehicle, Michal Podhradský Dec 2016

A Multi-Agent System For Adaptive Control Of A Flapping-Wing Micro Air Vehicle, Michal Podhradský

Dissertations and Theses

Biomimetic flapping-wing vehicles have attracted recent interest because of their numerous potential military and civilian applications. In this dissertation is described the design of a multi-agent adaptive controller for such a vehicle. This controller is responsible for estimating the vehicle pose (position and orientation) and then generating four parameters needed for split-cycle control of wing movements to correct pose errors. These parameters are produced via a subsumption architecture rule base. The control strategy is fault tolerant. Using an online learning process, an agent continuously monitors the vehicle's behavior and initiates diagnostics if the behavior has degraded. This agent can then …


Algorithm For Premature Ventricular Contraction Detection From A Subcutaneous Electrocardiogram Signal, Iris Lynn Shelly Dec 2016

Algorithm For Premature Ventricular Contraction Detection From A Subcutaneous Electrocardiogram Signal, Iris Lynn Shelly

Dissertations and Theses

Cardiac arrhythmias occur when the normal pattern of electrical signals in the heart breaks down. A premature ventricular contraction (PVC) is a common type of arrhythmia that occurs when a heartbeat originates from an ectopic focus within the ventricles rather than from the sinus node in the right atrium. This and other arrhythmias are often diagnosed with the help of an electrocardiogram, or ECG, which records the electrical activity of the heart using electrodes placed on the skin. In an ECG signal, a PVC is characterized by both timing and morphological differences from a normal sinus beat.

An implantable cardiac …


Pricing And Reliability Enhancements In The San Diego Activity-Based Travel Model, Joel Freedman Dec 2016

Pricing And Reliability Enhancements In The San Diego Activity-Based Travel Model, Joel Freedman

PSU Transportation Seminars

The estimation of demand for priced highway lanes is becoming increasingly important to agencies seeking to improve mobility and find alternative revenue sources for the provision of transportation infrastructure.

However, many modeling tools fall short of what is required for robust estimates of demand with respect to toll and managed lanes in two key areas:

  • The value-of-time is often aggregate and not consistently defined throughout the model system, and
  • The reliability of transport infrastructure is rarely taken into account.

This presentation describes an effort which implemented recommendations of the Strategic Highway Research Program C04 and L03\L04 tracks on pricing and …


Development Of 3d Accelerometer Testing System, Mohammed Abbas Soudai Alsaedi Dec 2016

Development Of 3d Accelerometer Testing System, Mohammed Abbas Soudai Alsaedi

Dissertations and Theses

Accelerometers are used in numerous industries including aircrafts and missile navigations systems, rotary machines, and electronic devices such as tablets, cell phones, and cameras. Accelerometers of different purposes and specifications are being produced in large quantities. The large demand for accelerometers forces the need for accelerometer testing methodology that is more convenient and accurate. Inertial Micro-Electromechanical Systems Accelerometer (MEMS) require a series of tests that include physical stimuli. One of the key challenges is the cost associated with testing. Therefore, the accurate prediction of the sensor functions not only reduces the testing time but also more importantly contributes to reducing …


Evaluation Of A Supervisor Training Program For Odot’S Ecodrive Program, Donald M. Truxillo, John Macarthur, Leslie B. Hammer, Talya N. Bauer Dec 2016

Evaluation Of A Supervisor Training Program For Odot’S Ecodrive Program, Donald M. Truxillo, John Macarthur, Leslie B. Hammer, Talya N. Bauer

TREC Final Reports

Eco-driving consists of using energy-efficient approaches to driving aimed at reducing fuel consumption and, ultimately, CO2 emissions. A previous study found that an EcoDrive informational campaign was effective at increasing the use of eco-driving behaviors, but only when employees perceived that their supervisor supported the program and when they were personally motivated to perform the eco-driving behaviors. In order to build upon the findings of our previous study, the present study focused on increasing the use of eco-driving behaviors through an informational eco-driving campaign combined with supervisor training to support the use of eco-driving practices.

In this study we collected …


Safety Effectiveness Of Pedestrian Crossing Enhancements, Christopher M. Monsere, Miguel Figliozzi, Sirisha Kothuri, Ali Razmpa, Daniel R. Hazel Dec 2016

Safety Effectiveness Of Pedestrian Crossing Enhancements, Christopher M. Monsere, Miguel Figliozzi, Sirisha Kothuri, Ali Razmpa, Daniel R. Hazel

Civil and Environmental Engineering Faculty Publications and Presentations

Over the last decade, the Oregon DOT and other agencies have systematically implemented many pedestrian crossing enhancements (PCEs) across the state. This study explored the safety performance of these enhanced crossing in Oregon. Detailed data were collected on 191 crossings. Supplemental data items included crossing location information, route characteristics, surrounding land use and crossing enhancement descriptions. Pedestrian volume at the crossing locations was a highly desirable but unavailable data element. To characterize pedestrian activity, a method was developed to estimate ranges for pedestrian crosswalk activity levels based on the land use classification at the census block level and the presence …


Investigating Co2 Removal By Ca- And Mg-Based Sorbents With Application To Indoor Air Treatment, Elliott T. Gall, Cem Sonat, William W. Nazaroff, Cise Unluer Dec 2016

Investigating Co2 Removal By Ca- And Mg-Based Sorbents With Application To Indoor Air Treatment, Elliott T. Gall, Cem Sonat, William W. Nazaroff, Cise Unluer

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor carbon dioxide (CO 2 ) levels serve as an indicator of ventilation sufficiency in relation to metabolic effluents. Recent evidence suggests that elevated CO 2 exposure (with or without other bioeffluents) may cause adverse cognitive effects. In shelter-in-place (SIP) facilities, indoor CO 2 levels may become particularly elevated. This study evaluates four low-cost alkaline earth metal oxides and hydroxides as CO 2 sorbents for potential use in indoor air cleaning applications. Sorbents studied were MgO, Mg(OH) 2 , Ca(OH) 2 and commercially available soda lime. Uncarbonated sorbents characterized with nitrogen adsorption porosimetry showed BET surface areas in the 5.6–27 …


Task And Participant Scheduling Of Trading Platforms In Vehicular Participatory Sensing Networks, Heyuan Shi, Xiaoyu Song, Ming Gu, Jiaguang Sun Dec 2016

Task And Participant Scheduling Of Trading Platforms In Vehicular Participatory Sensing Networks, Heyuan Shi, Xiaoyu Song, Ming Gu, Jiaguang Sun

Electrical and Computer Engineering Faculty Publications and Presentations

The vehicular participatory sensing network (VPSN) is now becoming more and more prevalent, and additionally has shown its great potential in various applications. A general VPSN consists of many tasks from task, publishers, trading platforms and a crowd of participants. Some literature treats publishers and the trading platform as a whole, which is impractical since they are two independent economic entities with respective purposes. For a trading platform in markets, its purpose is to maximize the profit by selecting tasks and recruiting participants who satisfy the requirements of accepted tasks, rather than to improve the quality of each task. This …


Using Blind Source Separation And A Compact Microphone Array To Improve The Error Rate Of Speech Recognition, Jeffrey Dean Hoffman Dec 2016

Using Blind Source Separation And A Compact Microphone Array To Improve The Error Rate Of Speech Recognition, Jeffrey Dean Hoffman

Dissertations and Theses

Automatic speech recognition has become a standard feature on many consumer electronics and automotive products, and the accuracy of the decoded speech has improved dramatically over time. Often, designers of these products achieve accuracy by employing microphone arrays and beamforming algorithms to reduce interference. However, beamforming microphone arrays are too large for small form factor products such as smart watches. Yet these small form factor products, which have precious little space for tactile user input (i.e. knobs, buttons and touch screens), would benefit immensely from a user interface based on reliably accurate automatic speech recognition.

This thesis proposes a solution …


Focused-Based Multifractal Analysis Of The Wake In A Wind Turbine Array Utilizing Proper Orthogonal Decomposition, Naseem Ali, Hawwa Falih Kadum, Raúl Bayoán Cal Nov 2016

Focused-Based Multifractal Analysis Of The Wake In A Wind Turbine Array Utilizing Proper Orthogonal Decomposition, Naseem Ali, Hawwa Falih Kadum, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Hot-wire anemometry measurements have been performed in a 3×3 wind turbine array to study the multifractality of the turbulent kinetic energy dissipation. A multifractal spectrum and Hurst exponents are determined at nine locations downstream of the hub height, bottom and top tips. Higher multifractality is found at 0.5D and 1D downstream of the bottom tip and hub height. The second order of the Hurst exponent and combination factor shows the ability to predict the flow state in terms of its development. Snapshot proper orthogonal decomposition (POD) is used to identify the coherent and incoherent structures and to reconstruct the stochastic …


Experimental Investigation Of Cfrp Wrapped Square Non-Ductile Reinforced Concrete Columns, Hayder Lateef Al-Khafaji Nov 2016

Experimental Investigation Of Cfrp Wrapped Square Non-Ductile Reinforced Concrete Columns, Hayder Lateef Al-Khafaji

Dissertations and Theses

The use of fiber-reinforced polymers (FRP) for retrofitting or strengthening deficient concrete columns noticeably increased in the past few decades. Plenty of research has been conducted on the behavior of FRP-strengthened circular concrete columns, but far less research has dealt with non-circular columns. In the current study, the focus was to investigate the behavior of square columns with low to medium grade concrete and low steel reinforcement that were strengthened using carbon fiber reinforced polymer (CFRP) wrap. In the experimental portion of this investigation, twelve short square reinforced concrete columns (5" x 5" in cross section and 12" high) were …


An Assessment Of Post-Encroachment Times For Bicycle-Vehicle Interactions Observed In The Field, A Driving Simulator, And In Traffic Simulation Models, Ali Razmpa Nov 2016

An Assessment Of Post-Encroachment Times For Bicycle-Vehicle Interactions Observed In The Field, A Driving Simulator, And In Traffic Simulation Models, Ali Razmpa

Dissertations and Theses

Most safety analysis is conducted using crash data. Surrogate safety measures, such as various time-based measures of time-to-collision can be related to crash potential and used to gain insight into the frequency and severity of crashes at a specific location. One of the most common and acknowledged measures is post-encroachment time (PET) which defines the time between vehicles occupying a conflicting space. While commonly used in studies of motor vehicle interactions, studies of PET for bicycle-vehicle interactions are few. In this research, the PET of bicycle-vehicle interactions measured in the field, a driving simulator, and in a micro-simulation are compared. …


Investigation Of Jet Dynamics In Cross-Flow: Quantifying Volcanic Plume Behavior, Graham Freedland Nov 2016

Investigation Of Jet Dynamics In Cross-Flow: Quantifying Volcanic Plume Behavior, Graham Freedland

Dissertations and Theses

Volcanic eruption columns inject high concentrations of ash into the atmosphere. Some of this ash is carried downwind forming ash clouds in the atmosphere that are hazardous for private and commercial aviation. Current models rely on inputs such as plume height, duration, eruption rate, and meteorological wind fields. Eruption rate is estimated from plume height using relations that depend on the rate of air entrainment into the plume, which is not well quantified. A wind tunnel experiment has been designed to investigate these models by injecting a vertical air jet into a cross-flow. The ratio of the cross-flow and jet …


Designing A Continuously Variable Magnetic Gear, J. Pritchard, Pavithra Padmanathan, Jonathan Z. Bird Nov 2016

Designing A Continuously Variable Magnetic Gear, J. Pritchard, Pavithra Padmanathan, Jonathan Z. Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper investigates the performance capabilities of a continuously variable magnetic gearbox that utilizes a flux focusing rotor structure. A fractional slot stator winding is designed to couple to the outer rotor of an existing magnetic gearbox in order to enable the magnetic gearbox to operate with a variable gear ratio.


Distribution Of Mean Kinetic Energy Around An Isolated Wind Turbine And A Characteristic Wind Turbine Of A Very Large Wind Farm, Gerard Cortina, Marc Calaf, Raul Bayoan Cal Nov 2016

Distribution Of Mean Kinetic Energy Around An Isolated Wind Turbine And A Characteristic Wind Turbine Of A Very Large Wind Farm, Gerard Cortina, Marc Calaf, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

An isolated wind turbine and a very large wind farm are introduced into large-eddy simulations of an atmospheric boundary layer. The atmospheric flow is forced with a constant geostrophic wind and a time-varying surface temperature extracted from a selected period of the CASES-99 field experiment. A control volume approach is used to directly compare the transfer of mean kinetic energy around a characteristic wind turbine throughout a diurnal cycle considering both scenarios. For the very large wind farm case, results illustrate that the recovery of mean kinetic energy around a wind turbine is dominated by the vertical flux, regardless of …


Bioaerosol Deposition On An Air-Conditioning Cooling Coil, Yan Wu, Ailu Chen, Irvan Luhung, Elliott T. Gall, Qingliang Cao, Victor Wei-Chung Chang, William W. Nazaroff Nov 2016

Bioaerosol Deposition On An Air-Conditioning Cooling Coil, Yan Wu, Ailu Chen, Irvan Luhung, Elliott T. Gall, Qingliang Cao, Victor Wei-Chung Chang, William W. Nazaroff

Mechanical and Materials Engineering Faculty Publications and Presentations

This study is concerned with the role of a fin-and-tube heat exchanger in modifying microbial indoor air quality. Specifically, depositional losses of ambient bioaerosols and particles onto dry (not cooled) and wet (cool) coil surfaces were measured for different airspeeds passing through the test coil. Total, bacterial and fungal DNA concentrations in condensate water produced by a wet coil were also quantified by means of fluorescent dsDNA-binding dye and qPCR assays. Results revealed that the deposition of bioaerosols and total particles is substantial on coil surfaces, especially when wet and cool. The average deposition fraction was 0.14 for total DNA, …


Technology Trajectory Mapping Using Data Envelopment Analysis: The Ex-Ante Use Of Disruptive Innovation Theory On Flat Panel Technologies, Dong-Joon Lim, Timothy R. Anderson Nov 2016

Technology Trajectory Mapping Using Data Envelopment Analysis: The Ex-Ante Use Of Disruptive Innovation Theory On Flat Panel Technologies, Dong-Joon Lim, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

In this paper, we propose a technology trajectory mapping approach using Data Envelopment Analysis (DEA) that scrutinizes technology progress patterns from multidimensional perspectives. Literature reviews on technology trajectory mappings have revealed that it is imperative to identify key performance measures that can represent different value propositions and then apply them to the investigation of technology systems in order to capture indications of the future disruption. The proposed approach provides a flexibility not only to take multiple characteristics of technology systems into account but also to deal with various tradeoffs among technology attributes by imposing weight restrictions in the DEA model. …


Webinar: Transit Signal Priority Evaluation And Performance Measures, Miguel Figliozzi Oct 2016

Webinar: Transit Signal Priority Evaluation And Performance Measures, Miguel Figliozzi

TREC Webinar Series

Transit signal priority (TSP) can reduce transit delay at signalized intersections by making phasing adjustments. TSP is a relatively inexpensive tool to provide faster and more reliable transit service. This webinar addresses TSP real-word performance measures as well as data integration and evaluation challenges. Results of the TSP evaluation in an arterial corridor in Portland, Oregon indicate that a timely and effective TSP system requires a high degree of sophistication, monitoring, and maintenance. TSP timing is crucial to reduce transit delay.

Key takeaways include: performance measures, methodology, analysis of early green and red extension pros and cons, novel real-world results.


Exploring Length-Based Vehicle Count Data, Byad Ahmed Oct 2016

Exploring Length-Based Vehicle Count Data, Byad Ahmed

Civil and Environmental Engineering Master's Project Reports

The development of Intelligent Transportation Systems (ITS) requires high-quality traffic information within most urban areas worldwide, and under growing pressure for improving traffic management, there has been an increasing urge to collecting and monitoring of traffic data. One of the most reliable and recommended technology for drive thru or traffic control is the loop vehicle detection system. On the Portland freeway system, new software has been installed that allows the reporting of vehicle length in bins. This research investigates the use of this data (length based) by exploring time series analyses of the vehicle counts as freight and non-freight movement.


Inverse Structure Functions In The Canonical Wind Turbine Array Boundary Layer, Bianca Viggiano, Moira Gion, Naseem Ali, Murat Tutkun, Raúl Bayoán Cal Oct 2016

Inverse Structure Functions In The Canonical Wind Turbine Array Boundary Layer, Bianca Viggiano, Moira Gion, Naseem Ali, Murat Tutkun, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind tunnel measurements for a 3×3 canonical wind turbine array boundary layer are obtained using hot-wire anemometer velocity signals. Two downstream locations are considered, referring to the near- and far-wake, and 21 vertical points are acquired per profile. Velocity increments and exit distances are used to quantify inverse structure functions at both downstream locations. Inverse structure functions in the near-wake show a similar profile for the main vertical locations, but diverge as the moment is increased. In the far-wake, inverse structure functions converge toward a single function for all vertical location and moments. The scaling exponents for inverse structure functions …


Laser Doppler Velocimetry Using A Modified Computer Mouse, Edward D. Zaron Oct 2016

Laser Doppler Velocimetry Using A Modified Computer Mouse, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

A computer mouse has been modified for use as a low-cost laser Doppler interferometer and used to measure the two-component fluid velocity of a flowing soap film. The mouse sensor contains two vertical cavity surface emitting lasers, photodiodes, and signal processing hardware integrated into a single package, approximately 1 cm2 in size, and interfaces to a host computer via a standard USB port. Using the principle of self-mixing interferometry, whereby laser light re-enters the laser cavity after being scattered from a moving target, the Doppler shift and velocity of scatterers dispersed in the flow are measured. Observations of the boundary …


Puddle Jumping: Spontaneous Ejection Of Large Liquid Droplets From Hydrophobic Surfaces During Drop Tower Tests, Babek Attari, Mark M. Weislogel, Andrew Paul Wollman, Yongkang Chen, Trevor Snyder Oct 2016

Puddle Jumping: Spontaneous Ejection Of Large Liquid Droplets From Hydrophobic Surfaces During Drop Tower Tests, Babek Attari, Mark M. Weislogel, Andrew Paul Wollman, Yongkang Chen, Trevor Snyder

Mechanical and Materials Engineering Faculty Publications and Presentations

Large droplets and puddles jump spontaneously from sufficiently hydrophobicsurfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 104 times larger than their normal terrestrial counterparts. We provide and/or confirm quick and qualitative design guides for such “drop shooters” as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, and fluid properties including contact angle. The latter is determined via profile image comparisons with numerical …


Effect Of Fiber Material On Ozone Removal And Carbonyl Production From Carpets, Omed A. Abbass, David J. Sailor, Elliott T. Gall Oct 2016

Effect Of Fiber Material On Ozone Removal And Carbonyl Production From Carpets, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor air quality is affected by indoor materials such as carpets that may act as sources and/or sinks of gas-phase air pollutants. Heterogeneous reactions of ozone with carpets may result in potentially harmful products. In this study, indoor residential carpets of varying fiber types were tested to evaluate their ability to remove ozone, and to assess their role in the production of carbonyls when exposed to elevated levels of ozone. Tests were conducted with six types of new unused carpets. Two sets of experiments were conducted, the first measured ozone removal and ozone deposition velocities, and the second measured primary …


Memristor-Based Volistor Gates Compute Logic With Low Power Consumption, Muayad Aljafar, Marek Perkowski Oct 2016

Memristor-Based Volistor Gates Compute Logic With Low Power Consumption, Muayad Aljafar, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We introduce a novel volistor logic gate which uses voltage as input and resistance as output. Volistors rely on the diode-like behavior of rectifying memristors. We show how to realize the first logic level, counted from the input, of any Boolean function with volistor gates in a memristive crossbar network. Unlike stateful logic, there is no need to store the inputs as resistances, and computation is performed directly. The fan-in and fan-out of volistor gates are large and different from traditional memristor circuits. Compared to solely memristive stateful logic, a combination of volistors and stateful inhibition gates can significantly reduce …


Configuring The Urban Smart Grid: Transitions, Experimentation, And Governance, Anthony Michael Levenda Sep 2016

Configuring The Urban Smart Grid: Transitions, Experimentation, And Governance, Anthony Michael Levenda

Dissertations and Theses

In the face of challenges of energy security, decarbonization, resilience, and the replacement of aging infrastructure systems, federal, state, and local actors are facilitating the development of smart electricity networks to transition towards a more sustainable electricity system. In the United States, development of "smart grids" is being pursued as a national policy mandate and goal, promising that the deployment of smart grid technologies -- referring in general to digital information and communication technologies that sense, monitor, control and manage the electric grid -- will make electricity systems more environmentally sustainable and reliable, and at the same time, provide opportunities …


Assessing Latrine Use In Rural India: A Cross-Sectional Study Comparing Reported Use And Passive Latrine Use Monitors, Antara Sinha, Corey L. Nagel, Evan A. Thomas, Wolf P. Schmidt, Belen Torondel, Sophie Boisson, Thomas Clasen Sep 2016

Assessing Latrine Use In Rural India: A Cross-Sectional Study Comparing Reported Use And Passive Latrine Use Monitors, Antara Sinha, Corey L. Nagel, Evan A. Thomas, Wolf P. Schmidt, Belen Torondel, Sophie Boisson, Thomas Clasen

Mechanical and Materials Engineering Faculty Publications and Presentations

Although large-scale programs, like India's Total Sanitation Campaign (TSC), have improved latrine coverage in rural settings, evidence suggests that actual use is suboptimal. However, the reliability of methods to assess latrine use is uncertain. We assessed the reliability of reported use, the standard method, by comparing survey-based responses against passive latrine use monitors (PLUMs) through a cross-sectional study among 292 households in 25 villages in rural Odisha, India, which recently received individual household latrines under the TSC. PLUMs were installed for 2 weeks and householders responded to surveys about their latrine use behavior. Reported use was compared with PLUM results …


High-Performance Self-Powered Photodetectors Based On Zno/Zns Core-Shell Nanorod Arrays, Hailing Lin, Lin Wei, Cuncun Wu, Yanxue Chen, Shishen Yan, Liangmo Mei, Jun Jiao Sep 2016

High-Performance Self-Powered Photodetectors Based On Zno/Zns Core-Shell Nanorod Arrays, Hailing Lin, Lin Wei, Cuncun Wu, Yanxue Chen, Shishen Yan, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

In recent years, there is an urgent demand for high-performance ultraviolet photodetectors with high photosensitivity, fast responsivity, and excellent spectral selectivity. In this letter, we report a self-powered photoelectrochemical cell-type UV detector using the ZnO/ZnS core-shell nanorod array as the active photoanode and deionized water as the electrolyte. This photodetector demonstrates an excellent spectral selectivity and a rapid photoresponse time of about 0.04 s. And the maximum responsivity is more than 0.056 (A/W) at 340 nm, which shows an improvement of 180 % compared to detectors based on the bare ZnO nanorods. This improved photoresponsivity can be understood from the …


A Framework For Technology Transfer Potential Assessment, Judith Estep, Tugrul U. Daim Sep 2016

A Framework For Technology Transfer Potential Assessment, Judith Estep, Tugrul U. Daim

Engineering and Technology Management Faculty Publications and Presentations

This paper is motivated by a need to move research into application, specifically in the utility industry. There are many challenges facing the industry: an aging infrastructure, a growing population, and aggressive energy efficiency targets are just a few examples. Many technologies exist or are in development but the rate at which they are being adopted is slow. Despite a clear need to apply research results to the utility industry, a cursory review of how research proposals are evaluated within the utility industry confirms that technology transfer is only peripherally addressed. In addition, there is no mechanism to quantitatively assess …