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2005

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Iterative Methods For The Reconstruction Of Tomographic Images With Unconventional Source-Detector Configurations, Abey Mukkananchery Jan 2005

Iterative Methods For The Reconstruction Of Tomographic Images With Unconventional Source-Detector Configurations, Abey Mukkananchery

Theses and Dissertations

X-ray computed tomography (CT) holds a critical role in current medical practice for the evaluation of patients, particularly in the emergency department and intensive care units. Expensive high resolution stationary scanners are available in radiology departments of most hospitals. In many situations however, a small, inexpensive, portable CT unit would be of significant value. Several mobile or miniature CT scanners are available, but none of these systems have the range, flexibility or overall physical characteristics of a truly portable device. The main challenge is the design of a geometry that optimally trades image quality for system size. The goal of …

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Afm And C-Afm Studies Of Gan Films, Katherine Cooper Jan 2005

Afm And C-Afm Studies Of Gan Films, Katherine Cooper

Theses and Dissertations

This thesis uses the techniques of atomic force microscope (AFM) and conductive AFM (C-AFM) to study the conduction properties of n-type GaN films. A total of 16 samples were examined and grouped according to their surface morphologies and conduction behaviors. The most common type of surface morpliology was that of Ga-rich samples having undulating "hillocks" with interspersed holes. Although most of the samples had this common morphology, their local conduction behaviors were not all similar. Local I-V spectra of the tip-sample Schottky contact could be grouped according to three major types: low leakage, high leakage, and "p-type". The highest quality …

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Parental Memory Predictors Of Children's Daily Diabetes Management And Metabolic Control, Sheryl J. Kent Jan 2005

Parental Memory Predictors Of Children's Daily Diabetes Management And Metabolic Control, Sheryl J. Kent

Theses and Dissertations

This study examined, for the first time, specific links between parents' memory and children's diabetes behaviors and metabolic control. Data revealed that parental memory and responsibility predicted children's percentage of calories from fat and carbohydrates, and metabolic control, accounting for 7.3% of the variance in calories from fat and 18.5% of the variance in metabolic control for the total sample. These effects were stronger when limited to dietary behaviors of younger youth; parental memory accounted for 30.3% and 33.6% of the variance in percentage of calories from fat and carbohydrates, respectively, for younger children. Level of parent responsibility, with memory, …

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Characterization Of The Mechanisms By Which The Organophosphorus Compound Malathion Induces Apoptosis In L929 Murine Fibroblasts, Laila Masoud Ali Al-Alawi Jan 2005

Characterization Of The Mechanisms By Which The Organophosphorus Compound Malathion Induces Apoptosis In L929 Murine Fibroblasts, Laila Masoud Ali Al-Alawi

Theses

While acute organophosphorous compound poisoning due to inhibition of acetylcholinesterase is a well-established clinical entity, the existence of chronic poisoning due to exposure to low levels of organophosphorous compounds (below the threshold required for cholinergic clinical symptoms) is a hotly debated issue. In this study, we have evaluated the effects of noncholinergic doses of malathion (0.01-20 µM) on apoptosis of murine L929 fibroblasts. Employing flow cytometric and caspase activation analyses, we demonstrate that malathion induces apoptosis in L929 cells in a dose- and time-dependent manner. The initiator caspases (caspase-8 and caspase-9) as well as the effector caspase (caspase-3) were activated …

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Microwave Processing Of Fiber Reinforced Composites (Optimization Of Glass Reinforced Epoxy Curing Process), Mohamed Osama Ali Jan 2005

Microwave Processing Of Fiber Reinforced Composites (Optimization Of Glass Reinforced Epoxy Curing Process), Mohamed Osama Ali

Theses

Microwave curing of polymer matrix composites has proven to be an attractive substitute for conventional thermal curing. Industrial applications are currently developed including telecommunications, aerospace, food industry, enhancement concrete setting, composites manufacturing, and many others. Many universities and research centers around the globe are endeavoring to make use of this technology to the most. Common research objectives include homogeneity of the cure, the acceleration of cure kinetics, cure reaction mechanism, and enhancement of mechanical properties. In order to efficiently utilize this form of energy, precise control over power, temperature, and time were applied to achieve set goals: reduce cure time …

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Ductile Crack Growth Emanating From Sharp Notes In A Low Alloy Steel, Aladdin I. Abu-Assi Jan 2005

Ductile Crack Growth Emanating From Sharp Notes In A Low Alloy Steel, Aladdin I. Abu-Assi

Theses

Stable crack growth behavior emanating from a sharp notch is investigated. Material chosen for tests was EN 34 NiCrMo6 low alloy steel (akin to 4340/4330). Tests were carried out on CT specimens for various angles and ratios to obtain load vs, load-line displacement, Ρ-ΔLL, curves. Experimental results were analyzed. A normalization approach of Ρ-ΔLL curves has been attempted and all experimental curves were represented as a single characteristic curve. Such approach has been also applied on experimental data available from other experimental investigations and results were encouraging, as it may address transferability issue. Fracture surfaces were …

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Investigation Of Epoxy Resin Spreading On Glass Surfaces, Haneen Nemer Al-Dahdooh Jan 2005

Investigation Of Epoxy Resin Spreading On Glass Surfaces, Haneen Nemer Al-Dahdooh

Theses

The spreading of a small epoxy resin droplet (l.5tL) on a glass surface was examined with the objective of developing a new type of hydrophobic polymer coated glass which has the ability to reduce heat gain inside a building. The study covered three main aspects; the spreading kinetics of epoxy resin on a glass surface, the hydophopicity of the developed polymer-coated glass surface, and the reduction of solar radiation of this surface, As wettability and spreading phenomena arc a fundamental prerequisite for coating, the spreading kinetics of different curing agent concentrations (15:200, 18:200, 21:200) of epoxy resin on the glass …

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A Web Services Architecture For Umls Knowledge Sources, Parsa Mirhaji, Narendra Kunapareddy, Yanko Michea, Arunkumar Srinivasan Jan 2005

A Web Services Architecture For Umls Knowledge Sources, Parsa Mirhaji, Narendra Kunapareddy, Yanko Michea, Arunkumar Srinivasan

Faculty, Staff and Student Publications

A web service is a collection of industry standards to enable reusability of services and interoperability of heterogeneous applications. The UMLS Knowledge Source (UMLSKS) Server provides remote access to the UMLSKS and related resources. We propose a Web Services Architecture that encapsulates UMLSKS-API and makes it available in distributed and heterogeneous environments. This is the first step towards intelligent and automatic UMLS services discovery and invocation by computer systems in distributed environments such as web.

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Using Incomplete Citation Data For Medline Results Ranking, Jorge R Herskovic, Elmer V Bernstam Jan 2005

Using Incomplete Citation Data For Medline Results Ranking, Jorge R Herskovic, Elmer V Bernstam

Faculty, Staff and Student Publications

Information overload is a significant problem for modern medicine. Searching MEDLINE for common topics often retrieves more relevant documents than users can review. Therefore, we must identify documents that are not only relevant, but also important. Our system ranks articles using citation counts and the PageRank algorithm, incorporating data from the Science Citation Index. However, citation data is usually incomplete. Therefore, we explore the relationship between the quantity of citation information available to the system and the quality of the result ranking. Specifically, we test the ability of citation count and PageRank to identify "important articles" as defined by experts …

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Mercury Contamination Of Channel And Floodplain Sediments In Wilson Creek Watershed, Southwest Missouri, Willard E. Rodgers Ii Jan 2005

Mercury Contamination Of Channel And Floodplain Sediments In Wilson Creek Watershed, Southwest Missouri, Willard E. Rodgers Ii

Graduate Theses/Dissertations

Mercury (Hg) is a pollutant affecting aquatic environments and human health world wide. Sediments in urban streams can store Hg from historical industrial waste releases in channel and floodplain deposits. Subsequent erosion of these deposits can remobilize sediment-bound Hg impacting downstream receiving waters. This study describes the distribution of Hg in floodplain and channel sediments of Wilson Creek and its tributaries using geochemical sediment analysis and cesium-137 dating. The upper Wilson Creek watershed drains the southern two-thirds of Springfield, Missouri. Results indicate that Hg concentrations in overbank and active channel sediments along the entire stream length are elevated above the …

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Correlation Between Sol Scores And Personal Computer Ownership With Internet Access, Christy Yaple Jan 2005

Correlation Between Sol Scores And Personal Computer Ownership With Internet Access, Christy Yaple

OTS Master's Level Projects & Papers

This study was used to gain information about the success of underrepresented high school students with regard to SOL scores and having a personal computer with internet access. The following hypothesis was developed to guide this study: Magna Vista High School Educational Talent Search students having a personal computer with internet access will have a higher pass rate on Virginia Standards of Learning mathematics tests.

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Alternative High Schools On The Virginia Peninsula, Oliver Robertson Jan 2005

Alternative High Schools On The Virginia Peninsula, Oliver Robertson

OTS Master's Level Projects & Papers

To guide this study the following research goals were used: 1. Identify the number of seats in Peninsula alternative schools; 2. Identify the academic resources of those schools; 3. Identify the admittance criteria to those schools; 4. Identify the credit and degree the student receives at completion of those alternative schools; 5. Determine the future capacity of alternative high schools on the Virginia Peninsula.

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Old Dominion University Department Of Human Resources Customer Satisfaction Study, September C. Sanderlin Jan 2005

Old Dominion University Department Of Human Resources Customer Satisfaction Study, September C. Sanderlin

OTS Master's Level Projects & Papers

The problem of this study was to evaluate the level of customer satisfaction with the services provided by the Old Dominion University Department of Human Resources. The following goals provided direction to this study: 1) What are the Department of Human Resources' baseline service levels? 2)How effectively does the Department of Human Resources meet its customer's human needs? 3) What products and services can the Department of Human Resources improve to better meet its customers' needs? 4) What is the overall level of customer satisfaction with the Department of Human Resources?

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Attitudes Of Potential Employers In Southwestern Virginia Toward Hiring Newly Licensed Physical Therapist Assistants Who Are Graduates Of The Wytheville Community College Physical Therapist Assistant Program, Julia S. Jackson King Jan 2005

Attitudes Of Potential Employers In Southwestern Virginia Toward Hiring Newly Licensed Physical Therapist Assistants Who Are Graduates Of The Wytheville Community College Physical Therapist Assistant Program, Julia S. Jackson King

OTS Master's Level Projects & Papers

The research goals included: 1. Did employers of physical therapist assistants feel positively toward graduates of the Wytheville Community College Physical Therapist Assistant program? 2. Would an employer prioritize a new graduate from Wytheville over a new graduate from any other program if all other applicable experience was equal? 3. What did employers identify as the strengths and weaknesses of the Wytheville program?

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Human Resources Managers And The Family Medical Leave Act, Rhonda Taylor Jan 2005

Human Resources Managers And The Family Medical Leave Act, Rhonda Taylor

OTS Master's Level Projects & Papers

The following objectives were established to answer the problem: 1. Determine the opinions of Human Resources Managers regarding employees' use of Family Medical Leave; 2. Determine whether employees are excessively using Family Medical Leave benefits; 3. Determine Human Resources Managers topics for training on Family Medical Leave practices.

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Gender And Programming Language Preferences Of Computer Programming Students At Moraine Valley Community College, Dawn Patitucci Jan 2005

Gender And Programming Language Preferences Of Computer Programming Students At Moraine Valley Community College, Dawn Patitucci

OTS Master's Level Projects & Papers

The objectives of this study were to answer the following questions: 1. Are female programming students more likely to pursue study in certain programming languages than in other languages? 2. Are females more or less likely to pursue study in multiple programming languages than males? 3. As compared with the percentage of females working as computer programmers nationwide, are females over- or under-represented in certain language tracks at Moraine Valley Community College? 4. Which language(s) might be useful in attracting more females to computer programming and software development?

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Determining The Benefits Of Seeking Phlebotomy Program Approval From The National Accrediting Agency For Clinical Laboratory Sciences, Frankie Harris-Lyne Jan 2005

Determining The Benefits Of Seeking Phlebotomy Program Approval From The National Accrediting Agency For Clinical Laboratory Sciences, Frankie Harris-Lyne

OTS Master's Level Projects & Papers

The goals of this study were to answer the following questions: Do approved programs provide access to data not available for non-approved programs? Does a change from a non-approved program to an approved program change the curriculum model? Is it financially feasible for the college to seek program approval status? Does an approved program increase credibility in recruitment? Does graduation from an approved program allow students to enter the workforce more efficiently than graduates of non-approved programs?

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Student Reaction To The Use Of Classroom Performance And Personal Response Systems In College Level Courses, Edmund A. Donato Jan 2005

Student Reaction To The Use Of Classroom Performance And Personal Response Systems In College Level Courses, Edmund A. Donato

OTS Master's Level Projects & Papers

The goals of this study were established to determine: 1. How do students perceive the effectiveness of the Classroom Performance System and Personal Response Systems in engaging them in the learning process? 2. How do students perceive the effectiveness of the Classroom Performance System and Personal Response Systems in aiding educators with evaluating their learning?

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Effects Of Technology Education On Middle School Language Arts (Reading) Achievement, Mark A. Bolt Jan 2005

Effects Of Technology Education On Middle School Language Arts (Reading) Achievement, Mark A. Bolt

OTS Master's Level Projects & Papers

The purpose of this study was to compare eighth grade students at Rachel Carson Middle School who took eighth grade Technology Education and the effect it had on student achievement on the reading section of the Virginia English Standards of Learning test.

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Upper Limits On Gravitational Wave Bursts In Ligo’S Second Science Run, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres Jan 2005

Upper Limits On Gravitational Wave Bursts In Ligo’S Second Science Run, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics & Astronomy Faculty Publications

We perform a search for gravitational wave bursts using data from the second science run of the LIGO detectors, using a method based on a wavelet time-frequency decomposition. This search is sensitive to bursts of duration much less than a second and with frequency content in the 100–1100 Hz range. It features significant improvements in the instrument sensitivity and in the analysis pipeline with respect to the burst search previously reported by LIGO. Improvements in the search method allow exploring weaker signals, relative to the detector noise floor, while maintaining a low false alarm rate, O ( 0.1 ) μ …

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Search For Gravitational Waves From Primordial Black Hole Binary Coalescences In The Galactic Halo, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres Jan 2005

Search For Gravitational Waves From Primordial Black Hole Binary Coalescences In The Galactic Halo, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole binary coalescence with component masses in the range 0.2–1.0M⊙. The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing nonspinning black holes with masses in the range 0.2–1.0M⊙, we place an observational upper limit on the rate of primordial black hole coalescence of 63 per year …

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Upper Limits On A Stochastic Background Of Gravitational Waves, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres Jan 2005

Upper Limits On A Stochastic Background Of Gravitational Waves, B. P. Abbott, R. Abbott, Mario C. Diaz, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of Ω0

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Upper Limits From The Ligo And Tama Detectors On The Rate Of Gravitational-Wave Bursts, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Cristina V. Torres Jan 2005

Upper Limits From The Ligo And Tama Detectors On The Rate Of Gravitational-Wave Bursts, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

We report on the first joint search for gravitational waves by the TAMA and LIGO collaborations. We looked for millisecond-duration unmodeled gravitational-wave bursts in 473 hr of coincident data collected during early 2003. No candidate signals were found. We set an upper limit of 0.12 events per day on the rate of detectable gravitational-wave bursts, at 90% confidence level. From software simulations, we estimate that our detector network was sensitive to bursts with root-sum-square strain amplitude above approximately 1–3×10−19  Hz−1/2 in the frequency band 700-2000 Hz. We describe the details of this collaborative search, with particular emphasis on its advantages …

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Limits On Gravitational-Wave Emission From Selected Pulsars Using Ligo Data, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres Jan 2005

Limits On Gravitational-Wave Emission From Selected Pulsars Using Ligo Data, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics & Astronomy Faculty Publications

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10−24. These strain limits translate into limits on the equatorial ellipticities of the pulsars, …

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Electric-Field Generated By The Combustion Of Titanium In Nitrogen, Karen S. Martirosyan, Mona Setoodeh, Dan Luss Jan 2005

Electric-Field Generated By The Combustion Of Titanium In Nitrogen, Karen S. Martirosyan, Mona Setoodeh, Dan Luss

Physics & Astronomy Faculty Publications

A short temporal electrical impulse (duration of 30–150ms) was generated during the nitridation of mixtures of titanium and titanium nitride by a high temperature moving reaction front. The maximum voltage and current were generated in the combustion front region, in which the conversion of Ti to TiN was incomplete. The electric field (voltage up to 2V and current up to 60mA) decayed and vanished before the maximum combustion temperature was attained. The generation of an electric field during a rapid high-temperature nitridation is most probably due to the different diffusion velocities of charge carriers through the growing titanium nitride shell …

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Search For Gravitational Waves Associated With The Gamma Ray Burst Grb030329 Using The Ligo Detectors, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres Jan 2005

Search For Gravitational Waves Associated With The Gamma Ray Burst Grb030329 Using The Ligo Detectors, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Soumya Mohanty, Soma Mukherjee, Cristina V. Torres

Physics & Astronomy Faculty Publications

We have performed a search for bursts of gravitational waves associated with the very bright gamma ray burst GRB030329, using the two detectors at the LIGO Hanford Observatory. Our search covered the most sensitive frequency range of the LIGO detectors (approximately 80–−2048   Hz), and we specifically targeted signals shorter than ≃150  ms. Our search algorithm looks for excess correlated power between the two interferometers and thus makes minimal assumptions about the gravitational waveform. We observed no candidates with gravitational-wave signal strength larger than a predetermined threshold. We report frequency-dependent upper limits on the strength of the gravitational waves associated with …

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Phase Effects In The Diffraction Of Light: Beyond The Grating Equation, Stacy Wise, V. Quetschke, A. J. Deshpande, G. Mueller, D. H. Reitze, D. B. Tanner, B. F. Whiting, Y. Chen Jan 2005

Phase Effects In The Diffraction Of Light: Beyond The Grating Equation, Stacy Wise, V. Quetschke, A. J. Deshpande, G. Mueller, D. H. Reitze, D. B. Tanner, B. F. Whiting, Y. Chen

Physics & Astronomy Faculty Publications

Diffraction gratings affect the absolute phase of light in a way that is not obvious from the usual derivation of optical paths using the grating equation. For example, consider light which encounters first one and then the second of two parallel gratings. If one grating is moved parallel to its surface, the phase of the light diffracted from the grating pair is shifted by 2π each time the grating is moved by one grating constant, even though the geometric path length is not altered by the motion. This additional phase shift must be included when incorporating diffraction gratings in interferometers.

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Response Of Test Masses To Gravitational Waves In The Local Lorentz Gauge, Malik Rakhmanov Jan 2005

Response Of Test Masses To Gravitational Waves In The Local Lorentz Gauge, Malik Rakhmanov

Physics & Astronomy Faculty Publications

The local Lorentz gauge represents a natural coordinate frame for an observer to analyze the effect of gravitational waves on detectors, and has been widely used to describe the response of resonant bars. Its application to laser interferometers has thus far been restricted to the long-wavelength regime, in which the separation between the test masses is much less than the wavelength of the gravitational waves. In this paper we show that the local Lorentz gauge can be used for calculations of geodesic deviations of the masses even when their separation is comparable to or greater than the wavelength of the …

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First All-Sky Upper Limits From Ligo On The Strength Of Periodic Gravitational Waves Using The Hough Transform, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres Jan 2005

First All-Sky Upper Limits From Ligo On The Strength Of Periodic Gravitational Waves Using The Hough Transform, B. P. Abbott, R. Abbott, W. G. Anderson, Mario C. Diaz, Wm. R. Johnston, Soma Mukherjee, Soumya Mohanty, Cristina V. Torres

Physics & Astronomy Faculty Publications

We perform a wide parameter-space search for continuous gravitational waves over the whole sky and over a large range of values of the frequency and the first spin-down parameter. Our search method is based on the Hough transform, which is a semicoherent, computationally efficient, and robust pattern recognition technique. We apply this technique to data from the second science run of the LIGO detectors and our final results are all-sky upper limits on the strength of gravitational waves emitted by unknown isolated spinning neutron stars on a set of narrow frequency bands in the range 200–400   Hz. The best upper …

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Spatial Relationships Of Grassland Net Ecosystem Carbon Dioxide Exchange In A First-Order Agricultural Basin In Southern Ontario, Patrick S. Chahil Jan 2005

Spatial Relationships Of Grassland Net Ecosystem Carbon Dioxide Exchange In A First-Order Agricultural Basin In Southern Ontario, Patrick S. Chahil

Theses and Dissertations (Comprehensive)

This study quantified the midday (10:00 – 16:00) summer source/sink CO2 relationships of various land-use types, particularly grass-dominated riparian areas, using dynamic chamber techniques, while evaluating the relative contribution of root and microbial components towards the overall soil respiration. The influence of nearby agriculture and was related to elevated N and P, which were 40 and 1000% larger, respectively. A site adjacent to cropped fields showed similar (within 8%) study averaged soil respiration as an open grassland site, but 22% lower soil respiration than a riparian site 250-300 m downstream, which is adjacent to an open grassland fallow. A maple …

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