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Physical Sciences and Mathematics Commons

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Selected Works

2013

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Articles 1 - 30 of 1920

Full-Text Articles in Physical Sciences and Mathematics

Workshop | Body Worn Video Recorders: The Socio-Technical Implications Of Gathering Direct Evidence, Katina Michael, Alexander Hayes Jun 2015

Workshop | Body Worn Video Recorders: The Socio-Technical Implications Of Gathering Direct Evidence, Katina Michael, Alexander Hayes

Alexander Hayes Mr.

- From in-car video recording to body-worn video recording

- Exploring available technologies: how do they work, pros and cons

- Storing direct evidence in secure storage: factors to consider

- Citizens “shooting” back with POV tech – what are their rights?

- Crowdsourced sousveillance- harnessing public data for forensic profiling

- Police force policies and practices on the application of new media


Optimal Allocation Of Distributed Reactive Power Resources Under Network Constraints For System Loss Minimization, L Meegahapola, S Abbott, D Morrow, T Littler, D Flynn Dec 2013

Optimal Allocation Of Distributed Reactive Power Resources Under Network Constraints For System Loss Minimization, L Meegahapola, S Abbott, D Morrow, T Littler, D Flynn

Dr Lasantha G Meegahapola

Abstract-Reactive power control is an important control issue for distribution system operators due to increased penetration of distributed generation. The work presented in this paper utilizes the inherent reactive power capability of the doubly-fed induction generator (DFIG) based wind farms to optimize the system losses while considering the network constraints in the system. The IEEE-30 bus system was modified by installing DFIG based wind farms in the medium voltage (MV) region creating three wind clusters in the network. The steady-state analysis was conducted to illustrate the loss minimization capability of the DFIG based wind farms under different reactive power configurations. …


Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn Dec 2013

Frequency Dynamics During High Ccgt And Wind Penetrations, Lasantha Meegahapola, Damian Flynn

Dr Lasantha G Meegahapola

Frequency stability is the paramount concern for secure and reliable operation of a power system. High wind penetration levels are reported in power systems with high thermal generation, and hence its likely to result high wind and combined-cycle gas turbine (CCGT) penetrations during system operation since CCGTs are the most preferable choice for the thermal generation. The doubly-fed induction generators (DFIGs) do not provide any inertial response while the CCGTs have unique frequency response during the system frequency disturbances. Therefore, CCGT turbine response characteristics and the zero inertial response may influence on frequency dynamics of a power network. The main …


Coordinated Utilisation Of Wind Farm Reactive Power Capability For System Loss Optimisation, Lasantha Meegahapola, S Durairaj, D Flynn, B Fox Dec 2013

Coordinated Utilisation Of Wind Farm Reactive Power Capability For System Loss Optimisation, Lasantha Meegahapola, S Durairaj, D Flynn, B Fox

Dr Lasantha G Meegahapola

Most wind farms currently being installed are based upon doubly fed induction generator (DFIG) or direct-drive synchronous generator (DDSG) technology. Given that one of the impacts of introducing distributed generation is an alteration of steady-state power flows and voltages, both technologies are capable of providing local voltage support. Wind farms may, therefore, be included in optimal power flow (OPF) calculations to minimise fuel cost and/or network losses. The IEEE 30-bus system is considered as a case study, comparing fixed-speed induction generator (FSIG) requirements with DFIG capability. Results are presented for a range of DFIG capability modes, at varying system load …


Rfid-Based Anti-Theft Auto Security System With An Immobilizer, Geeth Jayendra, Sisil Kumarawadu, Lasantha Meegahapola Dec 2013

Rfid-Based Anti-Theft Auto Security System With An Immobilizer, Geeth Jayendra, Sisil Kumarawadu, Lasantha Meegahapola

Dr Lasantha G Meegahapola

This paper presents a novel radio frequency identification (RFID) based vehicle immobilizer system, which features low hacking probability while preserving the safety of the passengers of the hijacked vehicle. The immobilizer uses the active RFID technology where the tag is generated with comparatively large character sets. The receiving unit is intelligently integrated into three control circuits in the vehicle, namely, ignition circuit, power control unit, and automatic gear changing system, enabling it to bring the vehicle speed down to zero in a safe step by step manner. The anti-theft auto security system proposed here was tested under different weather conditions …


A Genetic Algorithm Based Approach To Lv Radial Distribution Feeders Load Reconfiguration, Geeth Jayendra, Sisil Kumarawadu, Lasantha Meegahapola Dec 2013

A Genetic Algorithm Based Approach To Lv Radial Distribution Feeders Load Reconfiguration, Geeth Jayendra, Sisil Kumarawadu, Lasantha Meegahapola

Dr Lasantha G Meegahapola

No abstract provided.


Spectroscopic And Physico-Chemical Characterization Of Ir(I) And Ru(Iii) Complexes Of 32-Membered Unsymmetrical Dinucleating Macrocyclic Ligand, Mohammad Mansoob Khan Dr Dec 2013

Spectroscopic And Physico-Chemical Characterization Of Ir(I) And Ru(Iii) Complexes Of 32-Membered Unsymmetrical Dinucleating Macrocyclic Ligand, Mohammad Mansoob Khan Dr

Dr. Mohammad Mansoob Khan

No abstract provided.


Mineralization Of Ancient Carbon In The Subsurface Of Riparian Forests, Noel P. Gurwick, Daniel M. Mccorkle, Peter M. Groffman, Arthur J. Gold, D. Q. Kellogg, Peter Seitz-Rundlett Dec 2013

Mineralization Of Ancient Carbon In The Subsurface Of Riparian Forests, Noel P. Gurwick, Daniel M. Mccorkle, Peter M. Groffman, Arthur J. Gold, D. Q. Kellogg, Peter Seitz-Rundlett

Arthur Gold

Microbial activity in saturated, subsurface sediments in riparian forests may be supported by recent photosynthate or ancient (>500 ybp) soil organic carbon (SOC) in buried horizons. Metabolism of ancient SOC may be particularly important in riparian zones, considered denitrification hot spots, because denitrification in the riparian subsurface is often C-limited, because buried horizons intersect deep flow paths, and because low C mineralization rates can support ecosystem-relevant rates of denitrification. Buried horizons are common where alluvial processes (stream migration, overbank flow) have dominated riparian evolution. Our objectives were to determine: (1) the extent to which ancient SOC directly supports subsurface …


Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho Dec 2013

Biogenic Synthesis, Photocatalytic, And Photoelectrochemical Performance Of Ag–Zno Nanocomposite, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho

Dr. Mohammad Mansoob Khan

The development of coupled photoactive materials (metal/semiconductor) has resulted in significant advancements in heterogeneous visible light photocatalysis. This work reports the novel biogenic synthesis of visible light active Ag–ZnO nanocomposite for photocatalysis and photoelectrode using an electrochemically active biofilm (EAB). The results showed that the EAB functioned as a biogenic reducing tool for the reduction of Ag+, thereby eliminating the need for conventional reducing agents. The as-prepared Ag–ZnO nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, diffuse reflectance spectroscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic experiments showed that the Ag–ZnO nanocomposite possessed excellent visible light photocatalytic activity …


Vaporization Enthalpies And Vapor Pressures Of Two Insecticide Components, Muscalure And Empenthrin, By Correlation Gas Chromatography, Jessica Spencer, James Chickos Dec 2013

Vaporization Enthalpies And Vapor Pressures Of Two Insecticide Components, Muscalure And Empenthrin, By Correlation Gas Chromatography, Jessica Spencer, James Chickos

James Chickos

No abstract provided.


Building Sustainable Societies: Exploring Sustainability Policy And Practice In The Age Of High Consumption, Cindy Isenhour Dec 2013

Building Sustainable Societies: Exploring Sustainability Policy And Practice In The Age Of High Consumption, Cindy Isenhour

Cindy Isenhour

This dissertation is an attempt to examine how humans in wealthy, post-industrial urban contexts understand sustainability and respond to their concerns given their sphere of influence. I focus specifically on sustainable consumption policy and practice in Sweden, where concerns for sustainability and consumer-based responses are strong. This case raises interesting questions about the relative strength of sustainability movements in different cultural and geo-political contexts as well as the specific factors that have motivated the movement toward sustainable living in Sweden.

The data presented here supports the need for multigenic theories of sustainable consumerism. Rather than relying on dominant theories of …


Titanium Oxide Nanotubes: Synthesis, Properties And Applications For Solar Energy Harvesting, Eugen Panaitescu Dec 2013

Titanium Oxide Nanotubes: Synthesis, Properties And Applications For Solar Energy Harvesting, Eugen Panaitescu

Eugen Panaitescu

Titanium oxide (titania) nanotubes, although relatively recently discovered (less than 15 years ago), have already shown great promise regarding solar energy harvesting applications, exhibiting very good photocatalytic and photovoltaic properties. An alternative anodization route for production of titania nanotubes at the surface of a titanium foil using chloride ions as catalyst instead of the routinely used highly toxic fluorides, is presented in this work. Moreover, the fabrication parameters are extensively studied, thus providing both an insight into the synthesis mechanism and hints towards possible process optimization routes. Although not forming uniformly over the sample surface and lacking long range ordering, …


Environmental And Socio-Economic Considerations For Aquaculture In Jervis Bay, Nsw, Alyssa Joyce, Ana M. Rubio, Pia C. Winberg Dec 2013

Environmental And Socio-Economic Considerations For Aquaculture In Jervis Bay, Nsw, Alyssa Joyce, Ana M. Rubio, Pia C. Winberg

Dr Pia C Winberg

No abstract provided.


Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S Dou Dec 2013

Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S Dou

Zengji Yue

Anisotropic interlayer magneto-transport properties have been studied over a broad range of temperatures and magnetic fields in p-type Sb2Te3 single crystals. Giant interlayer magnetoresistance (MR) of up to 400% was observed, which exhibits quadratic field dependences in low fields and becomes linear at high fields without any trend towards saturation. The interlayer MR displays strong anisotropy and is attributable to the anisotropy of the Fermi surface. The observed giant anisotropic interlayer MR could find applications in p-type Sb2Te3 based magneto-electronic devices.


Causal Mediation In A Survival Setting With Time-Dependent Mediators, Wenjing Zheng, Mark J. Van Der Laan Dec 2013

Causal Mediation In A Survival Setting With Time-Dependent Mediators, Wenjing Zheng, Mark J. Van Der Laan

Wenjing Zheng

The effect of an expsore on an outcome of interest is often mediated by intermediate variables. The goal of causal mediation analysis is to evaluate the role of these intermediate variables (mediators) in the causal effect of the exposure on the outcome. In this paper, we consider causal mediation of a baseline exposure on a survival (or time-to-event) outcome, when the mediator is time-dependent. The challenge in this setting lies in that the event process takes places jointly with the mediator process; in particular, the length of the mediator history depends on the survival time. As a result, we argue …


Targeted Maximum Likelihood Estimation Of Natural Direct Effect, Wenjing Zheng, Mark Van Der Laan Dec 2013

Targeted Maximum Likelihood Estimation Of Natural Direct Effect, Wenjing Zheng, Mark Van Der Laan

Wenjing Zheng

In many causal inference problems, one is interested in the direct causal effect of an exposure on an outcome of interest that is not mediated by certain intermediate variables. Robins and Greenland (1992) and Pearl (2000) formalized the definition of two types of direct effects (natural and controlled) under the counterfactual framework. Since then, identifiability conditions for these effects have been studied extensively. By contrast, considerably fewer efforts have been invested in the estimation problem of the natural direct effect. In this article, we propose a semiparametric efficient, multiply robust estimator for the natural direct effect of a binary treatment …


The Unexpectedly Bright Comet C/2012 F6 (Lemmon) Unveiled At Near-Infrared Wavelengths, Lucas Paganini, Michael A. Disanti, Michael J. Mumma, Geronimo L. Villanueva, Boncho P. Bonev, Jacqueline V. Keane, Erika L. Gibb, Hermann Boehnhardt, Karen J. Meech Dec 2013

The Unexpectedly Bright Comet C/2012 F6 (Lemmon) Unveiled At Near-Infrared Wavelengths, Lucas Paganini, Michael A. Disanti, Michael J. Mumma, Geronimo L. Villanueva, Boncho P. Bonev, Jacqueline V. Keane, Erika L. Gibb, Hermann Boehnhardt, Karen J. Meech

Erika Gibb

We acquired near-infrared spectra of the Oort cloud comet C/2012 F6 (Lemmon) at three different heliocentric distances (R h) during the comet's 2013 perihelion passage, providing a comprehensive measure of the outgassing behavior of parent volatiles and cosmogonic indicators. Our observations were performed pre-perihelion at R h = 1.2 AU with CRIRES (on 2013 February 2 and 4), and post-perihelion at R h = 0.75 AU with CSHELL (on March 31 and April 1) and R h = 1.74 AU with NIRSPEC (on June 20). We detected 10 volatile species (H2O, OH* prompt emission, C2H6, CH3OH, H2CO, HCN, CO, CH4, …


The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck Dec 2013

The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

It is generally accepted that the main cause of ultracold neutron (UCN) losses in storage traps is upscattering to the thermal energy range by hydrogen adsorbed on the surface of the trap walls. However, the data on which this conclusion is based are poor and contradictory. Here we report a measurement, performed at the Los Alamos National Laboratory UCN source, of the average energy of the flux of upscattered neutrons after the interaction of UCN with hydrogen bound in the semicrystalline polymer PMP (trade name TPX), [C6H12]n. Our analysis, performed with the mcnp code which applies …


Waste Management And Water Quality Issues In Coastal States Of Nigeria: The Ogun State Experience, Solomon Isiorho Dec 2013

Waste Management And Water Quality Issues In Coastal States Of Nigeria: The Ogun State Experience, Solomon Isiorho

S Isiorho

Waste dumping and inadequate waste management efforts are having adverse impact on the environment and humans in Nigerian coastal cities. Nine of the 36 states in Nigeria border the Atlantic Ocean. Twenty-five percent of the Nigerian population is found in the coastal states. These states, with the exception of Lagos, Ogun and Ondo, are more prone to petrochemical waste arising from petroleum exploration. Filed investigations, surveys and literature searches were conducted in order to accomplish the task of this research. Field studies included testing for dissolved oxygen, biological oxygen demand, nitrates, phosphates, total solids and pH.


Undergrduates Conference Attendance, A Win-Win Situation For Students And Their Home Institution, Solomon Isiorho Dec 2013

Undergrduates Conference Attendance, A Win-Win Situation For Students And Their Home Institution, Solomon Isiorho

S Isiorho

No abstract provided.


Upward Bound Program And Inquiry-Based Activities In Wetland Settings., Solomon Isiorho Dec 2013

Upward Bound Program And Inquiry-Based Activities In Wetland Settings., Solomon Isiorho

S Isiorho

No abstract provided.


Wetlands, Solomon Isiorho Dec 2013

Wetlands, Solomon Isiorho

S Isiorho

No abstract provided.


Water Quality Assessment Of A Mid-West City Water Distribution System, Solomon Isiorho, A Morse, N Flores Dec 2013

Water Quality Assessment Of A Mid-West City Water Distribution System, Solomon Isiorho, A Morse, N Flores

S Isiorho

No abstract provided.


When A Professor Becomes A Student Again!", Solomon Isiorho Dec 2013

When A Professor Becomes A Student Again!", Solomon Isiorho

S Isiorho

No abstract provided.


The Chair As A Leader Based On: "Managing People: A Guide For Department Chairs And Deans.", Solomon Isiorho Dec 2013

The Chair As A Leader Based On: "Managing People: A Guide For Department Chairs And Deans.", Solomon Isiorho

S Isiorho

No abstract provided.


Groundwater, Solomon Isiorho Dec 2013

Groundwater, Solomon Isiorho

S Isiorho

No abstract provided.


Sahel Drought, Solomon Isiorho Dec 2013

Sahel Drought, Solomon Isiorho

S Isiorho

No abstract provided.


Application Of Hydrogeologic Settings In Groundwater Vulnerability Mapping In Lagrange County, Indiana, Solomon Isiorho Dec 2013

Application Of Hydrogeologic Settings In Groundwater Vulnerability Mapping In Lagrange County, Indiana, Solomon Isiorho

S Isiorho

No abstract provided.


A Five-Year Well Data, What Can It Tell Us?, Solomon Isiorho, A Morse Dec 2013

A Five-Year Well Data, What Can It Tell Us?, Solomon Isiorho, A Morse

S Isiorho

No abstract provided.


Flood Plains, Solomon Isiorho Dec 2013

Flood Plains, Solomon Isiorho

S Isiorho

No abstract provided.