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Measurement and Analysis of Indoor Air Quality Conditions

Description: More than 80% of the people in urban regions and about 98% of cities in low and middle income countries have poor air quality according to the World Health Organization. People living in such environment suffer from many disorders like a headache, shortness of breath or even the worst diseases like lung cancer, asthma etc. The main objective of the thesis is to create awareness about the air quality and the factors that are causing air pollution to the people which is really important and provide tools at their convenience to measure and analyze the air quality. Taking real time air quality scenarios, various experiments were made using efficient sensors to study both the indoor and outdoor air quality. These experimental results will eventually help people to understand air quality better. An outdoor air quality data measurement system is developed in this research using Python programming to provide people an opportunity to retrieve and manage the air quality data and get the concentrations of the leading pollutants. The entire designing of the program is made to run with the help of a graphical user interface tool for the user, as user convenience is considered as one of the objectives of the thesis. A graphical user interface is made for the user convenience to visualize graphically the data from the database. The designed system is tested and used for the measurement and analysis of the outdoor air quality. This data will be available in the database so it can be used for analyzing the air quality data for several days or months or years. Using the GrayWolf system and the designed outdoor air quality data measurement system, both the indoor and outdoor air quality was measured to analyze and correlate.
Date: August 2016
Creator: Chidurala, Veena
Partner: UNT Libraries

ASME Material Challenges for Advanced Reactor Concepts

Description: This study presents the material Challenges associated with Advanced Reactor Concept (ARC) such as the Advanced High Temperature Reactor (AHTR). ACR are the next generation concepts focusing on power production and providing thermal energy for industrial applications. The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The heat exchanger required for AHTR is subjected to a unique set of conditions that bring with them several design challenges not encountered in standard heat exchangers. The corrosive molten salts, especially at higher temperatures, require materials throughout the system to avoid corrosion, and adverse high-temperature effects such as creep. Given the very high steam generator pressure of the supercritical steam cycle, it is anticipated that water tube and molten salt shell steam generators heat exchanger will be used. In this paper, the ASME Section III and the American Society of Mechanical Engineers (ASME) Section VIII requirements (acceptance criteria) are discussed. Also, the ASME material acceptance criteria (ASME Section II, Part D) for high temperature environment are presented. Finally, lack of ASME acceptance criteria for thermal design and analysis are discussed.
Date: July 1, 2013
Creator: Sabharwall, Piyush & Siahpush, Ali
Partner: UNT Libraries Government Documents Department

AC 2007-1844: An Innovative Mechanical and Energy Engineering Curriculum

Description: This paper discusses the addition of a new Department of Mechanical and Energy Engineering at the University of North Texas (UNT). Those involved see the curriculum for this new program as a new model of engineering education that parallels the innovations of UNTs current Learning to Learn (L2L) project-oriented concept course with the addition of innovative approaches for mechanical engineering and emphasis on energy engineering education.
Date: 2007
Creator: Michaelides, Efstathios & Mirshams, Reza
Partner: UNT College of Engineering

AN EXPERIMENTAL STUDY OF THE FLOW FIELD OF A TWO DIMENSIONAL PREMIXED TURBULENT FLAME

Description: A turbulent reacting shear layer in a premixed propane/air flow has been studied in a two dimensional combustor, with the flame stabilized behind a rearward facing streamlined step. Spark shadowgraphs show that in the range of velocities (7.5 to 22.5 m/sec corresponding to Reynolds numbers of .5 x 10{sup 4} cm{sup -1} to 1. 5 x 10{sup 4} cm{sup -1} ) and equivalence ratios (0.4 to 0.7) studied, the mixing layer is dominated by Brown~ Roshko type large coherent structures in both reacting and nonreacting flows. High speed schlieren movies show that these eddies are convected downstream and increase their size and spacing by combustion and coalescence with neighboring eddies. Tracing individual eddies shows, in the reacting shear layer, that, on the average, eddies accelerate as they move downstream with the highest acceleration close to the origin of the shear layer. Combustion is confined to these large structures which develop as a result of vortical action of the shear flow. On the average, the reacting eddies have a lower growth rate than nonreacting eddies. A turbulent boundary layer created by means of a tripping wire upstream of the edge of the step virtually eliminates the large coherent structures in the shear layer, while for the case in which the wire could not trigger the transition to turbulence, the large coherent structures dominated the reacting and nonreacting flows.
Date: April 1, 1980
Creator: Ganji, A.R. & Sawyer, R.F.
Partner: UNT Libraries Government Documents Department

THERMOPHORETIC VELOCITY OF LARGE AEROSOL PARTICLES

Description: The velocity of thermal repulsion of large aerosol particles has been calculated by others by equating the thermal force on a stationary partlcle to the Stokes-Cunningham viscous force. This procedure is theoretically unsound because the boundary conditions employed in the viscous force equation are erroneous when the particle moves in a thermal gradient. In the current study these difficulties have been circumvented by rederiving the thermal force equation, allowing for a relative velocity between the particle and the gas stream. The velocity of motion is then calculated by setting the net force on the particle equal to zero. The velocity obtained by this more realistic approach agrees with that calculated by the former method, which is surprising in view of the incorrect boundary conditions employed in the former method. Investigation of the drag force equation shows that the thermal force and the viscous force are exerted independently of each other, which explains this unexpected agreement, The range of applicability of the analysis is explored by comparison with available experimental data,
Date: November 1, 1965
Creator: Postma, A. K.
Partner: UNT Libraries Government Documents Department

PHYSICAL EFFECTS OF THE HANFORD WINDSTORMS OF JANUARY 11, 1972 AND JANUARY 21, 1972

Description: The windstorm of January 11 caused a minor amount of damage to the Hanford Reservation and Hanford vicinity. Damage sustained to Hanford Reservation structures (roofing, flashing, fences, windows) was approximately $20,000. One building did receive structural damage to roof members. Evidence that wind pressures did not reach 30 lb/ft{sup 2} during the January 11 windstorm was provided in the fact that specially designed exterior wall panels did not fail. These panels were designed and carefully proof-tested to insure that they would fail at a loading of 30 lb/ft{sup 2} as a requirement of structural safety in the original design-construction program in 1952-1954. There was one power outage on the Hanford Reservation due to the January 11 windstorm (Rattlesnake Mountain Observatory). Damage to power lines and electrical facilities amounted to about $1600. Damage to structures in the Hanford vicinity (excluding the Hanford Reservation) from the January 11 windstorm was estimated to cost $13,000. This does not include damage to private residences, etc., which has been estimated by others to be near $250,000. Power line damage in the Hanford vicinity amounted to about $80,000, of which $60,000 was accounted for in the loss of four transmission towers in the tie-line between Priest Rapids and Wanapum Dams. The January 21 windstorm, which struck Toppenish, Washington, was a straight-wind of the catabatic foehn type and not a tornado-type wind as described in newspaper accounts. No funnel cloud was associated with this windstorm. The maximum gust was about 85 mph at 30 ft above the ground. Cost estimates of damage in Toppenish were not available. There were no power outages or structural damage on the Hanford Reservation from the January 21 windstorm. Total damage to the Hanford Reservation from the two windstorms was estimated to be about $22,500.
Date: June 1, 1972
Creator: Henager, C. H. & Fuquay, J. J.
Partner: UNT Libraries Government Documents Department

Computational fluid dynamic modeling of fluidized-bed polymerization reactors

Description: Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.
Date: November 2, 2012
Creator: Rokkam, Ram
Partner: UNT Libraries Government Documents Department

LESSONS LEARNED - STARTUP AND TRANSITION TO OPERATIONS AT THE 200 WEST PUMP AND TREAT FACILITY

Description: This document lists key Lessons Learned from the Startup Team for the 200 West Pump and Treat Facility Project. The Startup Team on this Project was an integrated, multi-discipline team whose scope was Construction Acceptance Testing (CAT), functional Acceptance Testing Procedures (ATP), and procedure development and implementation. Both maintenance and operations procedures were developed. Included in the operations procedures were the process unit operations. In addition, a training and qualification program was also part of the scope.
Date: October 3, 2012
Creator: DE, FINK; GG, BERGQUIST & SP, BURKE
Partner: UNT Libraries Government Documents Department

Laser Fusion: The First Ten Years 1962-1972

Description: This account of the beginning of the program on laser fusion at Livermore in 1962, and its subsequent development during the decade ending in 1972, was originally prepared as a contribution to the January 1991 symposium 'Achievements in Physics' honoring Professor Keith Brueckner upon his retirement from the University of San Diego at La Jolla. It is a personal recollection of work at Livermore from my vantage point as its scientific leader, and of events elsewhere that I thought significant. This period was one of rapid growth in which the technology of high-power short-pulse lasers needed to drive the implosion of thermonuclear fuel to the temperature and density needed for ignition was developed, and in which the physics of the interaction of intense light with plasmas was explored both theoretically and experimentally.
Date: June 25, 2004
Creator: Kidder, R. E.
Partner: UNT Libraries Government Documents Department

Effective Specific Impulse of a Pulsed Rocket Engine

Description: The specific impulse achieved in a pulsed rocket engine augmented with a fissioning nuclear bomb could be greater than that of any continuous flow engine. To a certain extent, this increase in specific impulse would be obtained at the expense of motor weight and average thrust. This paper considers the first of these limitations, motor weight, and estimates the highest effective specific impulse to be expected from a nuclear-pulsed rocket motor with respect to the weight of the motor.
Date: May 5, 1965
Creator: Platt, E. A. & Hanner, D. W.
Partner: UNT Libraries Government Documents Department

TIME-WALK CHARACTERISTICS OF AN IMPROVED CONSTANT FRACTION DISCRIMINATOR

Description: A modification to a constant fraction discriminator design published earlier makes the observed time walk less than 30 ps over an input voltage range of 0.15 to 2.5 V. This performance makes time-walk corrections unnecessary in many situations.
Date: September 1, 1980
Creator: Wozniak, G. J.; Richardson, L. W. & Maier, M. R.
Partner: UNT Libraries Government Documents Department