137 Matching Results

Search Results

Advanced search parameters have been applied.

METAL-MATRIX COMPOSITES AND THERMAL SPRAY COATINGS FOR EARTH MOVING MACHINES

Description: First quarter activities were limited to initial project discussions, laboratory preparation, and some initial coupon preparation. Technical discussion were held with the subcontractors to clearly define their roll in the project. Detailed preparation of the pressure casting lab were started. Initial test coupons were sprayed and provided to Oak Ridge National Lab for infrared lamp fusion trials.
Date: July 1, 2001
Creator: Kiser, Matthew T.
Partner: UNT Libraries Government Documents Department

Compact light source performance in recessed type luminaires

Description: Photometric comparisons were made with an indoor, recessed, type luminaire using incandescent, high intensity discharge and compact fluorescent lamps. The test results show substantial performance advantages, as expected, for the discharge light sources where the efficacy gains can be in the order for 400% even when including the ballast losses associated with the discharge lamps. The candlepower distribution patterns emerging from these luminaries are also different from those associated with the baseline incandescent lamps, and which are in some ways, even more desirable from a uniformity of illuminance perspective. A section on fluorescent lamp starting is also included which describes a system having excellent starting characteristics in terms of electrode starting temperature (RH/RC technique), proper operating frequency to minimize unwanted IR interactions, and satisfactory current crest factor values to help insure life performance.
Date: November 1, 1998
Creator: Hammer, E.E.
Partner: UNT Libraries Government Documents Department

Basic Research Needs for Solid-State Lighting. Report of the Basic Energy Sciences Workshop on Solid-State Lighting, May 22-24, 2006

Description: The workshop participants enthusiastically concluded that the time is ripe for new fundamental science to beget a revolution in lighting technology. SSL sources based on organic and inorganic materials have reached a level of efficiency where it is possible to envision their use for general illumination. The research areas articulated in this report are targeted to enable disruptive advances in SSL performance and realization of this dream. Broad penetration of SSL technology into the mass lighting market, accompanied by vast savings in energy usage, requires nothing less. These new ?good ideas? will be represented not by light bulbs, but by an entirely new lighting technology for the 21st century and a bright, energy-efficient future indeed.
Date: May 24, 2006
Creator: Phillips, J. M.; Burrows, P. E.; Davis, R. F.; Simmons, J. A.; Malliaras, G. G.; So, F. et al.
Partner: UNT Libraries Government Documents Department

Achieving Energy Savings with Highly-Controlled Lighting in an Open-Plan Office

Description: An installation in a Federal building tested the effectiveness of a highly-controlled, workstation-specific lighting retrofit. The study took place in an open-office area with 86 cubicles and low levels of daylight. Each cubicle was illuminated by a direct/indirectpendant luminaire with three 32 watt lamps, two dimmable DALI ballasts, and an occupancy sensor. A centralized control system programmed all three lamps to turn on and off according to occupancy on a workstation-by-workstation basis. Field measurements taken over the course of several monthsdemonstrated 40% lighting energy savings compared to a baseline without advanced controls that conforms to GSA's current retrofit standard. A photometric analysis found that the installation provided higher desktop light levels than the baseline, while an occupant survey found that occupants in general preferred the lighting system to thebaseline.Simple payback is fairly high; projects that can achieve lower installation costs and/or higher energy savings and those in which greenhouse gas reduction and occupant satisfaction are significant priorities provide the ideal setting for workstation-specific lighting retrofits.
Date: April 19, 2010
Creator: Rubinstein, Francis & Enscoe, Abby
Partner: UNT Libraries Government Documents Department

An In-Situ Photometric and Energy Analysis of a Sulfur LampLighting System

Description: This paper describes the results of a photometric and energy analysis that was conducted on a new light guide and sulfur lamp system recently installed at the U.S. Department of Energy's Forrestal Building. This novel system couples two high lumen output, high efficiency sulfur lamps to a single 73 m (240 ft.) hollow light guide lined with a reflective prismatic film. The system lights a large roadway and plaza area that lies beneath a section of the building. It has been designed to completely replace the grid of 280 mercury vapor lamps formerly used to light the space. This paper details the results of a field study that characterizes the significant energy savings and increased illumination levels that have been achieved. Comparisons to modeled HID lighting scenarios are also included.
Date: June 1, 1995
Creator: Crawford, Doug; Gould, Carl; Packer, Michael; Rubinstein,Francis & Siminovitch, Michael
Partner: UNT Libraries Government Documents Department

Analyzing occupancy profiles from a lighting controls field study

Description: Despite a number of published studies on the effectiveness of lighting controls in buildings, only one US study examines the occupancy patterns of building occupants. Occupancy profiles allow one to determine, for example, the probability that an office is occupied for each hour of the workday. Occupancy profiles are useful for many purposes including: (1) predicting the effectiveness of occupancy sensors for reducing peak demand, (2) evaluating the impact of human activity on building lighting and other electric loads and (3) providing lighting equipment manufacturers with detailed lighting operation data to help evaluate the impact of advanced lighting controls on equipment life. In this paper, we examine the occupancy profiles for 35 single person offices at a large office building in San Francisco and analyze the data to obtain average occupancy as a function of time of day. In addition, we analyzed the data to identify how the use of occupancy sensors may affect switching cycles and lamp life.
Date: April 30, 2003
Creator: Rubinstein, Francis; Colak, Nesrin; Jennings, Judith & Neils, Danielle
Partner: UNT Libraries Government Documents Department

Gelcasting Polycrystalline Alumina

Description: OSRAM SYLVANIA INC. is a major U.S. manufacturer of high-intensity lighting. Among its products is the Lumalux TM line of high-pressure sodium vapor arc lamps, which are used for industrial, highway, and street lighting. The key to the performance of these lamps is the polycrystalline alumina (PCA) tube that is used to contain the plasma that is formed in the electric arc. That plasma consists of ionized sodium, mercury, and xenon vapors. The key attributes of the PCA tubes are their transparency ({approximately}97% total transmittance in the visible), their refractoriness (inner wall temperature can reach l2OOC), and their chemical resistance (sodium and mercury vapor are extremely corrosive). The current efficiency of the lamps is very high, up to 100 initial lumens per watt. (Compare incandescent lamps 10-20 lumens per watt, fluorescent lamps 25-90 lumens per watt.)
Date: January 1, 2000
Creator: Janney, M.A.; Zuk, K.J. & Wei, G.C.
Partner: UNT Libraries Government Documents Department

An Assessment of the U.S. Residential Lighting Market

Description: This report provides background data upon which residential lighting fixture energy conservation programs can be built. The current stock of residential lighting is described by usage level, lamp wattage, fixture type, and location within the house. Data are discussed that indicate that 25% of residential fixtures are responsible for 80% of residential lighting energy use, and that justify targeting these fixtures as candidates for retrofit with energy-efficient fixtures. Fixtures determined to have the highest energy use are hardwired ceiling fixtures in kitchens, living/family rooms, dining rooms, and outdoors. An assessment of the market for residential fixtures shows that nearly half of new residential fixtures are imported, 61% of new fixtures sold are hardwired, and about half of all new fixtures sold are for ceiling installation.
Date: October 1, 1995
Creator: Jennings, Judy; Brown, Rich; Moezzi, Mithra; Mills, Evan & Sardinsky, Robert
Partner: UNT Libraries Government Documents Department

IC-BASED CONTROLS FOR ENERGY-EFFICIENT LIGHTING

Description: A new approach for driving high frequency energy saving ballasts is developed and documented in this report. The developed approach utilizes an IC-based platform that provides the benefits of reduced system cost, reduced ballast size, and universal application to a wide range of lamp technologies, such as linear fluorescent lamps (LFL), compact fluorescent lamps (CFL) and high intensity discharge lamps (HID). The control IC chip set developed for the platform includes dual low voltage (LV) IC gate drive that provides gate drive for high and low side power switches in typical ballast circuits, and ballast controller IC that provides control functionalities optimal for different lamps and digital interface for future extension to more sophisticated control and communication.
Date: March 1, 2005
Creator: Zhang, Richard
Partner: UNT Libraries Government Documents Department

New energy efficient torchieres ready for hot torchiere market

Description: The extraordinary market growth of the high power halogen torchiere (halogen uplighter) presents significant global energy savings opportunities for energy efficient alternatives. Extensive developed of prototype designs of energy efficient torchiere systems using compact fluorescent lamps (CFLs) has lead directly to the production and commercialization of CFL torchieres. This paper analyzes the current global market for torchieres and compares the electrical and photometric characteristics of one of the new CFL torchieres to standard tungsten halogen torchieres. Power assessments and photometric data indicate that the new CFL torchiere provides significant energy savings over the standard tungsten halogen torchiere while producing more luminous flux. The energy savings is jointly due to the high source efficacy of the CFLs and the poor performance of many cheaply made halogen lamps. Laboratory and in-situ experiments indicate that the CFL torchieres use 65 Watts to produce 25% more light than the 300 W tungsten halogen torchieres they are designed to replace. Additionally, the CFL torchieres have the benefit of a cooler lamp operating temperature, making them safer luminaires (Brooks, 1997; New York Times, 1997). This safety benefit, coupled with the potential for significant reductions in global greenhouse gas emissions, has prompted the insurance industry to form a unique alliance with energy conservation groups to promote energy efficient torchieres.
Date: November 1, 1997
Creator: Page, E.; Mills, E. & Siminovitch, M.
Partner: UNT Libraries Government Documents Department

Metal-Matrix Composites and Thermal Spray Coatings for Earth Moving Machines

Description: In the eighth quarter, investigations in both thrusts focused on abrasive wear characterization. For the steel matrix composites, various systems were tested at DOE Albany Research Center using wear tests which produced low stress scratching, high stress gouging, and gouging and impact wear. Based on the wear results, it is uncertain as to whether the composites created have sufficient wear resistance to provide a 2x life increase in a selectively reinforced component in all applications. High stress component abrasive wear tests were conducted at Caterpillar on arc lamp processed, thermal sprayed components. Testing showed that in many cases, arc lamp processing parameters and resulting fusion were insufficient to prevent coating spallation. Of those coatings which experienced only limited spallation, wear life improvements approached 2x and it is expected that project goals can be met with additional process modifications. An overview of the progress during the 8th quarter of this project is given below. Additional research details are provided in the limited rights appendix to this report.
Date: January 1, 2003
Creator: Weaver, D. Trent; Kiser, Matthew T. & Hawk, Jeffrey
Partner: UNT Libraries Government Documents Department

Thermoluminescence dating apparatus efficiency measurement using a standard light source

Description: The thermoluminescence (TL) apparatus used for the MMA-BNL dating project has been especially designed to improve upon light collection and transmission properties, when compared to most currently used dating systems. Two methods of light collection have been developed: one employing aspheric reflectors and the other using a reflector and lens system. In order to compare the relative effectiveness of these two systems, and to compare their performance against theoretical predictions or future improvements, a standard lamp and housing has been developed and calibrated. Two types of miniature lamps were evaluated for this purpose and their characteristics are shown in tables.
Date: January 1, 1978
Creator: Carriveau, G W
Partner: UNT Libraries Government Documents Department

Performance of Personal Workspace Controls Final Report

Description: One of the key deliverables for the DOE-funded controls research at LBNL for FY04 was the development of a prototype Personal Workspace Control system. The successful development of this system is a critical milestone for the LBNL Lighting Controls Research effort because this system demonstrates how IBECS can add value to today's Task Ambient lighting systems. LBNL has argued that by providing both the occupant and the facilities manager with the ability to precisely control the operation of overhead lighting and all task lighting in a coordinated manner, that task ambient lighting can optimize energy performance and occupant comfort simultaneously [Reference Task Ambient Foundation Document]. The Personal Workspace Control system is the application of IBECS to this important lighting problem. This report discusses the development of the Personal Workspace Control to date including descriptions of the different fixture types that have been converted to IBECS operation and a detailed description of the operation of PWC Scene Controller, which provides the end user with precise control of his task ambient lighting system. The objective, from the Annual Plan, is to demonstrate improvements in efficiency, lighting quality and occupant comfort realized using Personal Workspace Controls (PWC) designed to optimize the delivery of lighting to the individual's workstation regardless of which task-ambient lighting solution is chosen. The PWC will be capable of controlling floor-mounted, desk lamps, furniture-mounted and overhead lighting fixtures from a personal computer and handheld remote. The PWC will use an environmental sensor to automatically monitor illuminance, temperature and occupancy and to appropriately modulate ambient lighting according to daylight availability and to switch off task lighting according to local occupancy. [Adding occupancy control to the system would blunt the historical criticism of occupant-controlled lighting - the tendency of the occupant to leave lights on]. The PWC will be an entirely open ...
Date: December 1, 2004
Creator: Rubinstein, Francis; Kiliccote, Sila; Loffeld, John; Pettler,Pete & Snook, Joel
Partner: UNT Libraries Government Documents Department

ELECTROLUMINESCENT MATERIAL FOR FLAT PANEL DISPLAY

Description: The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop a new-generation electroluminescent (EL) material for flat panel displays and related applications by using unique and complementary research capabilities at Oak Ridge National Laboratory and OSRAM Sylvania, Inc. The goal was to produce an EL material with a luminance 10 times greater than conventional EL phosphors. An EL material with this increased luminance would have immediate applications for flat panel display devices (e.g., backlighting for liquid-crystal diodes) and for EL lamp technology. OSRAM Sylvania proposed that increased EL phosphor luminance could be obtained by creating composite EL materials capable of alignment under an applied electric field and capable of concentrating the applied electric field. Oak Ridge National Laboratory used pulsed laser deposition as a method for making these composite EL materials. The materials were evaluated for electroluminescence at laboratory facilities at OSRAM Sylvania, Inc. Many composite structures were thus made and evaluated, and it was observed that a composite structure based on alternating layers of a ferroelectric and a phosphor yielded electroluminescence. An enabling step that was not initially proposed but was conceived during the cooperative effort was found to be crucial to the success of the composite structure. The CRADA period expired before we were able to make quantitative measurements of the luminance and efficiency of the composite EL material. Future cooperative work, outside the scope of the CRADA, will focus on making these measurements and will result in the production of a prototype composite EL device.
Date: November 13, 2000
Creator: Smith, D.B.
Partner: UNT Libraries Government Documents Department

An Integrated Solid-State LED Luminaire for General Lighting

Description: A strong systems approach to designing and building practical LED-based replacement lamps is lacking. The general method of taking high-performance LEDs and marrying them to standard printed circuit boards, drivers and a heat sink has fallen short of the promise of LED lighting. In this program, a top-down assessment of requirements and a bottom-up reinvention of LED sources, electronics, optics and mechanics have resulted in the highest performance lamp possible. The team, comprised of Color Kinetics, the leaders in LED lighting and Cree, the leaders in LED devices took an approach to reinvent the package, the driver and the overall form and aesthetic of a replacement source. The challenge was to create a new benchmark in LED lighting - the resultant lamp, a PAR38 equivalent, met the light output, color, color quality and efficacy marks set out in the program as well as being dimmable, which is important for market acceptance. The approach combined the use of multiple source die, a chip-on-board approach, a very efficient driver topology, the use of both direct emission and phosphor conversion, and a unique faceted optic to avoid the losses, artifacts and hotspots of lensed approaches. The integral heat sink provided a mechanical base and airflow using a chimney-effect for use in a wide variety of locations and orientations. These research results led to a much better understanding of the system effects of component level technologies. It was clear that best-of-breed sub-system results do not necessarily result in the best end result for the complete system. In doing this work, we did not neglect the practical aspects of these systems. These were not rarified results and commercially impractical but lent themselves to eventual commercial products in the marketplace. The end result - a high performance replacement lamp - will save significant energy while providing ...
Date: March 31, 2009
Creator: Dowling, Kevin; Lys, Fritz Morgan Ihor; Datta, Mike; Keller, Bernd & Yuan, Thomas
Partner: UNT Libraries Government Documents Department

15 KJ FLASH LAMP, POWER CONDITIONING UNIT DESIGNED FOR SAFTY, RELIABILITY & MANUFACTURABILITY*

Description: A 15kJoule, Flash Lamp Power Conditioning Unit has been successfully designed, developed, and deployed in the National Ignition Facility (NIF) Preamplifier Modules (PAM). The primary design philosophy of this power conditioning unit (PCU) is safety, reliability, and manufacturability. Cost reduction over commercially equivalent systems was also achieved through an easily manufactured packaging design optimized to meet NIF requirements. While still maintaining low cost, the PCU design includes a robust control system, fault diagnostic system, and safety features. The pulsed power design includes 6 PFN modules, each including a dual series injection trigger transformer, that drive a total of 12 flash lamp loads. The lamps are individually triggered via a 20kV pulse produced by a 1kV, MCT switched capacitive discharge unit on the primary side of the trigger transformer. The remote control interface includes an embedded controller that captures flash lamp current wave forms and fault status for each shot. The embedded controller provides the flexibility of remotely adjusting both the main drive voltage from 1.6 to 2.5 kV and the trigger voltage from 0 to 20 kV.
Date: August 7, 2007
Creator: James, G; Merritt, B; Dreifuerst, G & Strickland, S
Partner: UNT Libraries Government Documents Department

Efficient White SSL Component for General Illumination

Description: Cree has developed a new, high-efficiency, low-cost, light emitting diode (LED) module that should be capable of replacing standard, halogen, fluorescent and metal halide lamps based on the total cost of ownership. White LEDs are produced by combining one or more saturated color LEDs with a phosphor or other light down-converting media to achieve white broad-band illumination. This two year project addressed LED chip, package and phosphor efficiency improvements to establish a technology platform suitable for low-cost, high-efficiency commercial luminaires. New phosphor materials with improved quantum efficiency at 'real-life' operating conditions were developed along with new package technology to improve the efficiency of warm white LED modules compared to the baseline technology. Specifically, Cree has successfully demonstrated warm white LED modules providing 540 lumens at a correlated color temperature (CCT) of 3000 K. The LED module had an efficacy of 102.8 lumens per watt (LPW) using 1 mm2 chips biased at 350 mA - a 27% improvement over the technology at project start (81 LPW at 3000K). The white modules also delivered an efficacy of 88 LPW at elevated junction temperatures of 125 C. In addition, a proof-of-concept 4-inch downlight luminaire produced a flux of 1183 lumens at a CCT of 2827 K and a color rendering index (CRI) of 80 using this project's phosphor developments.
Date: January 31, 2011
Creator: Evans, Sean
Partner: UNT Libraries Government Documents Department

Novel Nanophosphors for High Efficiency Fluorescent Lamps

Description: This is the Yearly Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. Our chief achievement, during the current contract period, pertains to the successful synthesis and characterization of coated phosphors. We demonstrated several synthesis techniques for the coating of micron sized commercial phosphors with quantum-splitting and UV emitting nanophosphors. We have also continued our fundamental investigations into the physical processes that determine the quantum efficiency of the nanophosphors and this has further helped codify a set of rules for the host lattice that support efficient quantum splitting and UV emission at room temperature. In this report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.
Date: September 30, 2005
Creator: Srivastava, Alok M.
Partner: UNT Libraries Government Documents Department

High Efficancy Integrated Under-Cabinet Phosphorescent OLED

Description: In this two year program Universal Display Corporation (UDC) together with the University of Michigan, Teknokon, developed and delivered an energy efficient phosphorescent OLED under cabinet illumination system. Specifically the UDC team goal was in 2011 to deliver five (5) Beta level OLED under cabinet lighting fixtures each consisting of five 6-inch x 6-inch OLED lighting panels, delivering over 420 lumens, at an overall system efficacy of >60 lm/W, a CRI of >85, and a projected lifetime to 70% of initial luminance to exceed 20,000 hours. During the course of this program, the Team pursued the commercialization of these OLED based under cabinet lighting fixtures, to enable the launch of commercial OLED lighting products. The UDC team was ideally suited to develop these novel and efficient solid state lighting fixtures, having both the technical experience and commercial distribution mechanisms to leverage work performed under this contract. UDC's business strategy is to non-exclusively license its PHOLED technology to lighting manufacturers, and also supply them with our proprietary PHOLED materials. UDC is currently working with several licensees who are manufacturing OLED lighting panels using our technology. During this 2 year program, we further developed our high efficiency white Phosphorescent OLEDs from the first milestone, achieving a 80 lm/W single pixel to the final milestone, achieving an under-cabinet PHOLED lighting system that operates at 56 lm/W at 420 lumens. Each luminaire was comprised of ten 15cm x 7.5cm lighting modules mounted in outcoupling enhancement lenses and a control module. The lamps modules are connected together using either plugs or wires with plugs on each end, allowing for unlimited configurations. The lamps are driven by an OLED driver mounted in an enclosure which includes the AC plug. As a result of advancements gained under this program, the path to move OLED lighting panels from ...
Date: October 31, 2001
Creator: Hack, Michael
Partner: UNT Libraries Government Documents Department

Qualification and Demonstration Program for SSCL Lighting Systems In Park and Highway Applications

Description: Meadow River Enterprises, Inc. (MRE) received a DOE cooperative agreement award in March of 2002 to develop Qualification and Demonstration Program for SSCL Lighting Systems in Parks and Highway Applications. (The SSCL lighting technology is the same technology that was developed under a DOE cooperative agreement DE-FC26-99FT40631.) This project spanned a period of 39 months and ended in June of 2005. Participates in the funding of this project included the US Department of Energy, Rahall Transportation Institute, West Virginia State Parks System, and Meadow River Enterprises, Inc. The total program costs totaled $850,000. The federal contribution to the program totaled $150,000 which represented 17.6% of the total costs. The SSCL is a rugged electroluminescent lamp and was designed for outdoor applications. However, since this is a new technology, there have never been any housing or solar packages assemble for its use in these outdoor applications. The purpose of this program was to develop several types of encasements and solar packages, then evaluate their performances over time. At the end of observations, a conclusion would be reached as to the methodology of encasement and solar package requirements. In addition this project was to evaluate the viability of this application for the SSCL product. In addition this project was to evaluate the feasibility of etching the top conductive layer of the SSCL panel to permit only the needed area to be illuminated; this would reduce the power requirements of a sign. All primary development objectives have been achieved.
Date: June 30, 2005
Creator: Osborne, Don
Partner: UNT Libraries Government Documents Department

Controls for Solid-State Lighting

Description: This study predicts new hybrid lighting applications for LEDs. In hybrid lighting, LEDs provide a low-energy 'standby' light level while another, more powerful, efficient light source provides light for occupied periods. Lighting controls will allow the two light sources to work together through an appropriate control strategy, typically motion-sensing. There are no technical barriers preventing the use of low through high CRI LEDs for standby lighting in many interior and exterior applications today. The total luminous efficacy of LED systems could be raised by increasing the electrical efficiency of LED drivers to the maximum practically achievable level (94%). This would increase system luminous efficacy by 20-25%. The expected market volumes for many types of LEDs should justify the evolution of new LED drivers that use highly efficient ICs and reduce parts count by means of ASICs. Reducing their electronics parts count by offloading discrete components onto integrated circuits (IC) will allow manufacturers to reduce the cost of LED driver electronics. LED luminaire manufacturers will increasingly integrate the LED driver and thermal management directly in the LED fixture. LED luminaires of the future will likely have no need for separable lamp and ballast because the equipment life of all the LED luminaire components will all be about the same (50,000 hours). The controls and communications techniques used for communicating with conventional light sources, such as dimmable fluorescent lighting, are appropriate for LED illumination for energy management purposes. DALI has been used to control LED systems in new applications and the emerging ZigBee protocol could be used for LEDs as well. Major lighting companies are already moving in this direction. The most significant finding is that there is a significant opportunity to use LEDs today for standby lighting purposes. Conventional lighting systems can be made more efficient still by using LEDs to ...
Date: June 22, 2007
Creator: Rubinstein, Francis
Partner: UNT Libraries Government Documents Department

Scintillator Based Energetic Ion Loss Diagnostic for the National Spherical Torus Experiment

Description: A scintillator based energetic ion loss detector has been built and installed on the National Spherical Torus Experiment (NSTX) to measure the loss of neutral beam ions. The detector is able to resolve the pitch angle and gyroradius of the lost energetic ions. It has a wide acceptance range in pitch angle and energy, and is able to resolve the full, one-half, and one-third energy components of the 80 keV D neutral beams up to the maximum toroidal magnetic field of NSTX. Multiple Faraday cups have been embedded behind the scintillator to allow easy absolute calibration of the diagnostic and to measure the energetic ion loss to several ranges of pitch angle with good time resolution. Several small, vacuum compatible lamps allow simple calibration of the scintillator position within the field of view of the diagnostic's video camera.
Date: July 2, 2007
Creator: Darrow, D.S.
Partner: UNT Libraries Government Documents Department

CO2 MONITORING FOR DEMAND CONTROLLED VENTILATION IN COMMERCIAL BUILDINGS

Description: Carbon dioxide (CO{sub 2}) sensors are often deployed in commercial buildings to obtain CO{sub 2} data that are used, in a process called demand-controlled ventilation, to automatically modulate rates of outdoor air ventilation. The objective is to keep ventilation rates at or above design specifications and code requirements and also to save energy by avoiding excessive ventilation rates. Demand controlled ventilation is most often used in spaces with highly variable and sometime dense occupancy. Reasonably accurate CO{sub 2} measurements are needed for successful demand controlled ventilation; however, prior research has suggested substantial measurement errors. Accordingly, this study evaluated: (a) the accuracy of 208 CO{sub 2} single-location sensors located in 34 commercial buildings, (b) the accuracy of four multi-location CO{sub 2} measurement systems that utilize tubing, valves, and pumps to measure at multiple locations with single CO{sub 2} sensors, and (c) the spatial variability of CO{sub 2} concentrations within meeting rooms. The field studies of the accuracy of single-location CO{sub 2} sensors included multi-concentration calibration checks of 90 sensors in which sensor accuracy was checked at multiple CO{sub 2} concentrations using primary standard calibration gases. From these evaluations, average errors were small, -26 ppm and -9 ppm at 760 and 1010 ppm, respectively; however, the averages of the absolute values of error were 118 ppm (16%) and 138 ppm (14%), at concentrations of 760 and 1010 ppm, respectively. The calibration data are generally well fit by a straight line as indicated by high values of R{sup 2}. The Title 24 standard specifies that sensor error must be certified as no greater than 75 ppm for a period of five years after sensor installation. At 1010 ppm, 40% of sensors had errors greater than {+-}75 ppm and 31% of sensors has errors greater than {+-}100 ppm. At 760 ppm, 47% of sensors ...
Date: March 17, 2010
Creator: Fisk, William J.; Sullivan, Douglas P.; Faulkner, David & Eliseeva, Ekaterina
Partner: UNT Libraries Government Documents Department