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Measurement of Visibility From the Pilot's Cockpit on Different Airplane Types

Description: A process for the measurement of the visibility of airplanes from the pilot's cockpit is developed. The apparatus necessary for the measurements was suitably constructed and measurements of the fields of vision were made with it. The visibilities of six airplanes of different types of construction and use were measured, as well as the visibility of an automobile for comparison. An attempt was made to establish minimum visibility requirements and to express the excellence of visibility by means of a numerical coefficient.
Date: November 1931
Creator: Kurz, Gerhard
Partner: UNT Libraries Government Documents Department

The AWM-SIAM Sonia Kovalesvky Lecture - 3 part Lecture Series

Description: The Association for Women in Mathematics (AWM) in cooperation with the Society for Industrial and Applied Mathematics (SIAM) and with funding from the Department of Energy initiated a new lecture series. The purpose of the lecture series is to increase the visibility of women who have made significant contributions in applied or computational mathematics. The AWM-SIAM Sonia Kovalevsky Lecture is presented at the SIAM Annual Meeting which is a national conference. The lecturer is a woman who has made distinguished contributions in applied or computational mathematics. The lecturer is determined by the Selection Committee which consists of two members of AWM and two members of SIAM, appointed by the presidents of these organizations. The committee may solicit nominations from other members of the scientific and engineering community. The lectureship may be awarded to any woman in the scientific or engineering community.
Date: June 3, 2003
Creator: Lenhart, Suzanne & Lewis, Jennifer
Partner: UNT Libraries Government Documents Department

On the Importance of Organic Oxygen for Understanding OrganicAerosol Particles

Description: This study shows how aerosol organic oxygen data could provide new information about organic aerosol mass, aqueous solubility of organic aerosols, formation of secondary organic aerosol (SOA) and the relative contributions of anthropogenic and biogenic sources. For more than two decades atmospheric aerosol organic mass (OM) concentration has been estimated by multiplying the measured carbon content by an assumed (OM)-to-organic carbon (OC) factor, usually 1.4. However, this factor can vary from 1.0 to 2.5 depending on location. This large uncertainty about aerosol organic mass limits our understanding of the influence of organic aerosol on climate, visibility and health. New examination of organic aerosol speciation data shows that the oxygen content is responsible for the observed range in the OM-to-OC factor. When organic oxygen content is excluded, the ratio of non-oxygen organic mass to carbon mass varies very little across different environments (1.12 to 1.14). The non-oxygen-OM-to-OC factor for all studied sites (urban and non-urban) averaged 1.13. The uncertainty becomes an order of magnitude smaller than the uncertainty in the best current estimates of organic mass to organic carbon ratios (1.6 {+-} 0.2 for urban and 2.1 {+-} 0.2 for non-urban areas). This analysis suggests that, when aerosol organic oxygen data become available, organic aerosol mass can be quite accurately estimated using just OC and organic oxygen (OO) without the need to know whether the aerosol is fresh or aged. In addition, aerosol organic oxygen data will aid prediction of water solubility since compounds with OO-to-OC higher than 0.4 have water solubilities higher than 1 g per 100 g water.
Date: April 1, 2005
Creator: Pang, Y.; Turpin, B.J. & Gundel, L.A.
Partner: UNT Libraries Government Documents Department

Analyzing Tradeoffs between Privacy Concerns and Active Social Media Presence of 18- to 30-Year-Old College Students

Description: This study applied the impression management theory in the context of social networking to investigate the generalized research question of this dissertation which is "Do active social media presence and various privacy concerns influence online behaviors of students on social media?" The results and conclusions are presented via the conduct of three different studies and the summary provides insights and explain the overall contribution of the research. For each study we developed a research model for which data was collected separately for each of these models. Hypotheses of each model were tested by partial least squares- structural equation modeling techniques using SmartPLS 2.0. Our findings confirm the hypotheses and showed that all the predictors positively influence online social networking behaviors. Active social media presence is operationalized as predictors such as SNS stalking awareness, Selective disclosure, desired differential persona, impression motivation, and information trustworthiness. Privacy concerns have been operationalized as SNS privacy awareness, technology awareness. Online behaviors have been operationalized as responsible image and reckless image.
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Date: August 2018
Creator: Gadgil, Guruprasad Yashwant
Partner: UNT Libraries

Fast polyhedral cell sorting for interactive rendering of unstructured grids

Description: Direct volume rendering based on projective methods works by projecting, in visibility order, the polyhedral cells of a mesh onto the image plane, and incrementally compositing the cell's color and opacity into the final image. Crucial to this method is the computation of a visibility ordering of the cells. If the mesh is ''well-behaved'' (acyclic and convex), then the MPVO method of Williams provides a very fast sorting algorithm; however, this method only computes an approximate ordering in general datasets, resulting in visual artifacts when rendered. A recent method of Silva et al. removed the assumption that the mesh is convex, by means of a sweep algorithm used in conjunction with the MPVO method; their algorithm is substantially faster than previous exact methods for general meshes. In this paper we propose a new technique, which we call BSP-XMPVO, which is based on a fast and simple way of using binary space partitions on the boundary elements of the mesh to augment the ordering produced by MPVO. Our results are shown to be orders of magnitude better than previous exact methods of sorting cells.
Date: October 30, 1998
Creator: Combra, J; Klosowski, J T; Max, N; Silva, C T & Williams, P L
Partner: UNT Libraries Government Documents Department

The Simplest Double Slit: Interference and Entanglement in Double Photoionization of H2

Description: The wave nature of particles is rarely seen in nature. One reason is their very short de Broglie wavelengths in most situations. However, even with wavelengths close to the size of their surroundings, they couple to their environment, e.g. by gravity, Coulomb interaction, or thermal radiation. These couplings shift the phase of the waves, often in an uncontrolled way, hence yielding varying amounts of decoherence i.e. loss of phase integrity. Decoherence is thought to be a main cause of the transition from quantum to classical behavior. How much interaction is necessary and how big an environment is needed to induce the onset of classical behavior? Here we show that a photoelectron and two protons form a minimum particle/slit system, and that a minimum environment can be no more than a single additional electron. We observe interference 'fringes' in the angular distribution of a single electron and the loss of fringe visibility caused by its Coulomb interaction with a second electron. While, at the same time, the correlated momenta of the entangled electron pair continue to exhibit quantum interference.
Date: September 18, 2007
Creator: Akoury , D.; Kreidi, K.; Jahnke , T.; Weber, Th.; Staudte , A.; Schoffler, M. et al.
Partner: UNT Libraries Government Documents Department

Hydrogen Technical Analysis -- Dissemination of Information

Description: SENTECH is a small energy and environmental consulting firm providing technical, analytical, and communications solutions to technology management issues. The activities proposed by SENTECH focused on gathering and developing communications materials and information, and various dissemination activities to present the benefits of hydrogen energy to a broad audience while at the same time establishing permanent communications channels to enable continued two-way dialog with these audiences in future years. Effective communications and information dissemination is critical to the acceptance of new technology. Hydrogen technologies face the additional challenge of safety preconceptions formed primarily as a result of the crash of the Hindenburg. Effective communications play a key role in all aspects of human interaction, and will help to overcome the perceptual barriers, whether of safety, economics, or benefits. As originally proposed SENTECH identified three distinct information dissemination activities to address three distinct but important audiences; these formed the basis for the task structure used in phases 1 and 2. The tasks were: (1) Print information--Brochures that target the certain segment of the population and will be distributed via relevant technical conferences and traditional distribution channels. (2) Face-to-face meetings--With industries identified to have a stake in hydrogen energy. The three industry audiences are architect/engineering firms, renewable energy firms, and energy companies that have not made a commitment to hydrogen (3) Educational Forums--The final audience is students--the future engineers, technicians, and energy consumers. SENTECH will expand on its previous educational work in this area. The communications activities proposed by SENTECH and completed as a result of this cooperative agreement was designed to compliment the research and development work funded by the DOE by presenting the technical achievements and validations of hydrogen energy technologies to non-traditional audiences. These activities were also designed to raise the visibility of the DOE Hydrogen Program to new audiences ...
Date: March 20, 2006
Creator: George Kervitsky, Jr.
Partner: UNT Libraries Government Documents Department

Barrow Meteoroloigcal Station (BMET) Handbook

Description: The Barrow meteorology station (BMET) uses mainly conventional in situ sensors mounted at four different heights on a 40 m tower to obtain profiles of wind speed, wind direction, air temperature, and humidity. It also obtains barometric pressure, visibility, and precipitation data.
Date: November 1, 2004
Creator: Ritsche, MT
Partner: UNT Libraries Government Documents Department

Surface and Tower Meteorological Instrumentation at Atqasuk (METTWR2H) Handbook

Description: The Atqasuk meteorology station (AMET) uses mainly conventional in situ sensors to measure wind speed, wind direction, air temperature, dew point, and humidity mounted on a 10-m tower. It also obtains barometric pressure, visibility and precipitation data from sensors at or near the base of the tower. In addition, a chilled mirror hygrometer (CMH) is located at 1 m for comparison purposes. Temperature and relative humidity (RH) probes are mounted at 2 m and 5 m on the tower.
Date: January 1, 2006
Creator: Ritsche, MT
Partner: UNT Libraries Government Documents Department

Surface and Tower Meteorological Instrumentation at Barrow (METTWR4H) Handbook

Description: The Barrow meteorology station (BMET) uses mainly conventional in situ sensors mounted at four different heights (2m, 10m, 20m and 40m) on a 40 m tower to obtain profiles of wind speed, wind direction, air temperature, dew point and humidity. It also obtains barometric pressure, visibility and precipitation data from sensors at the base of the tower. Additionally, a Chilled Mirror Hygrometer and an Ultrasonic wind speed sensor are located near the 2m level for comparison purposes.
Date: April 1, 2008
Creator: Ritsche, MT
Partner: UNT Libraries Government Documents Department

Numerical analysis of decoy state quantum key distribution protocols

Description: Decoy state protocols are a useful tool for many quantum key distribution systems implemented with weak coherent pulses, allowing significantly better secret bit rates and longer maximum distances. In this paper we present a method to numerically find optimal three-level protocols, and we examine how the secret bit rate and the optimized parameters are dependent on various system properties, such as session length, transmission loss, and visibility. Additionally, we show how to modify the decoy state analysis to handle partially distinguishable decoy states as well as uncertainty in the prepared intensities.
Date: January 1, 2008
Creator: Harrington, Jim W & Rice, Patrick R
Partner: UNT Libraries Government Documents Department

Update on DOE’s Nuclear Energy University Program

Description: The Center for Advanced Energy Studies (CAES) Nuclear Energy University Program Office assists the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) by administering its University Program. To promote accountable relationships between universities and the TIOs/TDOs, a process was designed and administered which includes two competitive Requests for Proposals (RFP’s) and two FOAs in the following areas: (1)Research and Development Grants, (2)Infrastructure improvement, and (3)Scholarships and Fellowships. NEUP will also host periodic reviews of university mission-specific R&D that document progress, reinforce accountability, and assess return on investment; sponsor workshops that inform universities of the Department’s research needs to facilitate continued alignment of university R&D with NE missions; and conduct communications activities that foster stakeholder trust, serve as a catalyst for accomplishing NEUP objectives, and provide national visibility of NEUP activities and accomplishments. Year to date efforts to achieve these goals will be discussed.
Date: April 1, 2009
Creator: Lambregts, M. J.
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume III P-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.

Description: In this volume (III), all P-wave measurements are presented that were performed in Borehole C4997 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 390 to 1220 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 40 ft (later relocated to 27.5 ft due to visibility in borehole after rain) in Borehole C4997, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4997, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.
Date: June 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Component evaluation testing and analysis algorithms.

Description: The Ground-Based Monitoring R&E Component Evaluation project performs testing on the hardware components that make up Seismic and Infrasound monitoring systems. The majority of the testing is focused on the Digital Waveform Recorder (DWR), Seismic Sensor, and Infrasound Sensor. In order to guarantee consistency, traceability, and visibility into the results of the testing process, it is necessary to document the test and analysis procedures that are in place. Other reports document the testing procedures that are in place (Kromer, 2007). This document serves to provide a comprehensive overview of the analysis and the algorithms that are applied to the Component Evaluation testing. A brief summary of each test is included to provide the context for the analysis that is to be performed.
Date: October 1, 2011
Creator: Hart, Darren M. & Merchant, Bion John
Partner: UNT Libraries Government Documents Department

Energy Efficiency Services Sector: Workforce Size and Expectations for Growth

Description: The energy efficiency services sector (EESS) is poised to become an increasingly important part of the U.S. economy. Climate change and energy supply concerns, volatile and increasing energy prices, and a desire for greater energy independence have led many state and national leaders to support an increasingly prominent role for energy efficiency in U.S. energy policy. The national economic recession has also helped to boost the visibility of energy efficiency, as part of a strategy to support economic recovery. We expect investment in energy efficiency to increase dramatically both in the near-term and through 2020 and beyond. This increase will come both from public support, such as the American Recovery and Reinvestment Act (ARRA) and significant increases in utility ratepayer funds directed toward efficiency, and also from increased private spending due to codes and standards, increasing energy prices, and voluntary standards for industry. Given the growing attention on energy efficiency, there is a concern among policy makers, program administrators, and others that there is an insufficiently trained workforce in place to meet the energy efficiency goals being put in place by local, state, and federal policy. To understand the likelihood of a potential workforce gap and appropriate response strategies, one needs to understand the size, composition, and potential for growth of the EESS. We use a bottom-up approach based upon almost 300 interviews with program administrators, education and training providers, and a variety of EESS employers and trade associations; communications with over 50 sector experts; as well as an extensive literature review. We attempt to provide insight into key aspects of the EESS by describing the current job composition, the current workforce size, our projections for sector growth through 2020, and key issues that may limit this growth.
Date: March 22, 2010
Creator: Goldman, Charles; Fuller, Merrian C.; Stuart, Elizabeth; Peters, Jane S.; McRae, Marjorie; Albers, Nathaniel et al.
Partner: UNT Libraries Government Documents Department

Atmospheric Visibility Assessment for Urban Areas Using Photographic Slides and Optical Densitometry

Description: The factors involved in calculating Standard Visual Range (SVR) are discussed, and a comparison is made between the visibility reported by airport observers and the photographic slide/ optical densitometer method of calculating SVR. Using slides of Houston, Texas, from the fall and winter of 1988-89, it was found that the altitude at which the contrast measurements are made significantly affects the SVR. Also an index for predicting high and low humidity was developed using the blue/red ratio of the log exposure of the sky, and sun/shade target condition.
Date: May 1992
Creator: Jacob, Mary Katherine
Partner: UNT Libraries

Characterization of a MEMS Accelerometer for Inertial Navigating Applications

Description: Inertial MEMS sensors such as accelerometers and angular rotation sensing devices continue to improve in performance as advances in design and processing are made. Present state-of-the-art accelerometers have achieved performance levels in the laboratory that are consistent with requirements for successful application in tactical weapon navigation systems. However, sensor performance parameters that are of interest to the designer of inertial navigation systems are frequently not adequately addressed by the MEMS manufacturer. This paper addresses the testing and characterization of a MEMS accelerometer from an inertial navigation perspective. The paper discusses test objectives, data reduction techniques and presents results from the test of a three-axis MEMS accelerometer conducted at Sandia National Laboratories during 1997. The test was structured to achieve visibility and characterization of the accelerometer bias and scale factor stability overtime and temperature. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energy under contract DE-AC04-94AL85000.
Date: February 12, 1999
Creator: Kinney, R.D.
Partner: UNT Libraries Government Documents Department

The DOE/NREL Environmental Science Program

Description: This paper summarizes the several of the studies in the Environmental Science Program being sponsored by DOE's Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The goal of the Environmental Science Program is to understand atmospheric impacts and potential health effects that may be caused by the use of petroleum-based fuels and alternative transportation fuels from mobile sources. The Program is regulatory-driven, and focuses on ozone, airborne particles, visibility and regional haze, air toxics, and health effects of air pollutants. Each project in the Program is designed to address policy-relevant objectives. Current projects in the Environmental Science Program have four areas of focus: improving technology for emissions measurements; vehicle emissions measurements; emission inventory development/improvement; ambient impacts, including health effects.
Date: May 14, 2001
Creator: Lawson, Douglas R. & Gurevich, Michael
Partner: UNT Libraries Government Documents Department

The DOE/NREL Environmental Science and Health Effects Program - An Overview

Description: This paper summarizes current work in the Environmental Science and Health Effects (ES and HE) Program being sponsored by DOE's Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The program is regulatory-driven, and focuses on ozone, airborne particles, visibility and regional haze, air toxics, and health effects of air pollutants. The goal of the ES and HE Program is to understand atmospheric impacts and potential health effects that may be caused by the use of petroleum-based and alternative transportation fuels. Each project in the program is designed to address policy-relevant objectives. Studies in the ES and HE Program have four areas of focus: improving technology for emissions measurements; vehicle emissions measurements, emission inventory development/improvement; and ambient impacts, including health effects.
Date: April 26, 1999
Creator: Lawson, Douglas R. & Gurevich, Michael
Partner: UNT Libraries Government Documents Department

Assessing the potential visibility benefits of Clean Air Act Title IV emission reductions

Description: Assessments are made of the benefits of the 1990 Clean Air Act Title IV (COVE), Phase 2, SO2 and NOX reduction provisions, to the visibility in typical eastern and western Class 1 areas. Probable bands of visibility impairment distribution curves are developed for Shenandoah National Park, Smoky Mountain National Park and the Grand Canyon National Park, based on the existing emissions, ``Base Case``, and for the COVE emission reductions, ``CAAA Case``. Emission projections for 2010 are developed with improved versions of the National Acid Precipitation Assessment Program emission projection models. Source-receptor transfer matrices created with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model are used with existing emission inventories and with the emission projections to calculate atmospheric concentrations of sulfate and nitrate at the receptors of interest for existing and projected emission scenarios. The Visibility Assessment Scoping Model (VASM) is then used to develop distributions of visibility impairment. VASM combines statistics of observed concentrations of particulate species and relative humidity with ASTRAP calculations of the relative changes in atmospheric sulfate and nitrate particulate concentrations in a Monte Carlo approach to produce expected distributions of hourly particulate concentrations and RH. Light extinction relationships developed in theoretical and field studies are then used to calculate the resulting distribution of visibility impairment. Successive Monte Carlo studies are carried out to develop sets of visibility impairment distributions with and without the COVE emission reductions to gain insight into the detectability of expected visibility improvements.
Date: June 1, 1995
Creator: Trexler, E.C. Jr. & Shannon, J.D.
Partner: UNT Libraries Government Documents Department

Effects of Fresnel fringes on TEM images of interfaces in X-ray multilayers

Description: Fresnel fringe effects make assessment of interfacial structures from high-resolution TEM images of cross-sectional specimens difficult, producing different apparent structures in the images. Fresnel fringes have been observed in many TEM images of W/C, WC/C, Ru/C, and Mo/Si, multilayers. Visibility of these fringes depends on the thickness of the specimen and the defocus value. Contrast of the fringes becomes higher with increasing defocus. The effects of these fringes have been commonly over-looked in efforts of making quantitative interpretation of interfacial profiles. In this report, we present the observations of the Fresnel fringes in nanometer period Mo/Si, W/C, and WC/C multilayers in through-focus-series TEM images. Calculation of the Fresnel fringes of a Mo/Si multilayer using charge density approximation is used to illustrate the characteristics of the fringes from different interfacial structures. We find that the potential difference and the abruptness of the interfacial composition change are a strong function of the fringe contrast, while the fringes spacing depends more strongly on the thickness of the transition or interfacial layer.
Date: March 2, 1992
Creator: Nguyen, Tai D.; O'Keefe, Michael A.; Kilaas, Roar; Gronsky, Ronald & Kortright, Jeffrey B.
Partner: UNT Libraries Government Documents Department