Science.gov

Sample records for recirculating facility built

  1. Recirculating Linear Accelerators for Future Muon Facilities

    SciTech Connect

    S.A. Bogacz, K.B.Beard, R.P. Johnson

    2010-05-01

    Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness.

  2. Recirculating Linac Accelerators For Future Muon Facilities

    SciTech Connect

    Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

    2012-04-01

    Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  3. Performance of the prototype gas recirculation system with built-in RGA for INO RPC system

    NASA Astrophysics Data System (ADS)

    Bhuyan, M.; Datar, V. M.; Joshi, A.; Kalmani, S. D.; Mondal, N. K.; Rahman, M. A.; Satyanarayana, B.; Verma, P.

    2012-01-01

    An open loop gas recovery and recirculation system has been developed for the INO RPC system. The gas mixture coming from RPC exhaust is first desiccated by passing through molecular sieve (3 Å+4 Å). Subsequent scrubbing over basic active alumina removes toxic and acidic contaminants. The Isobutane and Freon are then separated by diffusion and liquefied by fractional condensation by cooling up to -26C. A Residual Gas Analyser (RGA) is being used in the loop to study the performance of the recirculation system. The results of the RGA analysis will be discussed.

  4. 28. MAP SHOWING LOCATION OF ARVFS FACILITY AS BUILT. SHOWS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. MAP SHOWING LOCATION OF ARVFS FACILITY AS BUILT. SHOWS LINCOLN BOULEVARD, BIG LOST RIVER, AND NAVAL REACTORS FACILITY. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-101-2. DATED OCTOBER 12, 1965. INEL INDEX CODE NUMBER: 075 0101 851 151969. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  5. Feasibility study for a recirculating linac-based facility for femtosecond dynamics

    SciTech Connect

    Corlett, J.N.; Barry, W.; Barletta, W.A.; Byrd, J.M.; DeSantis, S.; Doolittle, L.; Fawley, W.; Green, M.A.; Hartman, N.; Heimann, P.; Kairan, D.; Kujawski, E.; Li, D.; Lidia, S.; Luft, P.; McClure, R.; Parmigiani, F.; Petroff, Y.; Pirkl, W.; Placidi, M.; Reavill, D.; Reichel, I.; Rimmer, R.A.; Ratti, A.; Robinson, K.E.; Sannibale, F.; Schoenlein, R.; Staples, J.; Tanabe, J.; Truchlikova, D.; Wan, W.; Wang, S.; Wells, R.; Wolski, A.; Zholents, A.

    2002-12-21

    LBNL is pursuing design studies and the scientific program for a facility dedicated to the production of x-ray pulses with ultra-short time duration, for application in dynamical studies of processes in physics, biology, and chemistry. The proposed x-ray facility has the short x-ray pulse length ({approx}60 fs FWHM) necessary to study very fast dynamics, high flux (up to approximately 10E11 photons/sec/0.1 percentBW) to study weakly scattering systems, and tuneability over 1-12 keV photon energy. The hard x-ray photon production section of the machine accommodates seven 2-m long undulators. Design studies for longer wavelength sources, using high-gain harmonic generation, are in progress. The x-ray pulse repetition rate of 10 kHz is matched to studies of dynamical processes (initiated by ultra-short laser pulses) that typically have a long recovery time or are not generally cyclic or reversible and need time to allow relaxation, replacement, or flow of the sample. The technique for producing ultra-short x-ray pulses uses relatively long electron bunches to minimize high-peak-current collective effects, and the ultimate x-ray duration is achieved by a combination of bunch manipulation and optical compression. Synchronization of x-ray pulses to sample excitation signals is expected to be of order 50 - 100 fs. Techniques for making use of the recirculating geometry to provide beam-based signals from early passes through the machine are being studied.

  6. Design, loading, and water quality in recirculating systems for low salinity finfish species at the USDA /ARS Sustainable Marine Aquaculture Systems facility (Fort Pierce, FL)

    USDA-ARS?s Scientific Manuscript database

    The USDA ARS Sustainable Marine Aquaculture System Facility was established by the USDA ARS in collaboration with Harbor Branch Oceanographic Institute / Florida Atlantic University to improve the efficiency and sustainability of inland warmwater marine fish culture in recirculating aquaculture syst...

  7. LUX - a recirculating linac-based facility for ultrafast X-ray science

    SciTech Connect

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Heimann, P.; Leone, S.; Lidia, S.; Li, D.; Penn, G.; Ratti, A.; Reinsch, M.; Schoenlein, R.; Staples, J.; Stover, G.; Virostek, S.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Wurtele, J.; Zholents, A.

    2004-06-29

    We present recent developments in design concepts for LUX - a source of ultra-short synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science [1]. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1-10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, independently tunable harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and resistive wall wakefields. Timing jitter between pump lasers and x-ray pulses is minimized by use of a stable optical master oscillator, distributing timing signals over actively stabilized fiber-optic, phase-locking all lasers to the master oscillator, and generating all rf signals from the master oscillator. We describe technical developments including techniques for minimizing power dissipation in a high repetition rate rf photocathode gun, beam dynamics in two injector configurations, independently tunable beamlines for VUV and soft x-ray production by cascaded harmonic generation, a fast kicker design, timing systems for providing synchronization between experimental pump lasers and the x-ray pulse, and beamline design for maintaining nm-scale density modulation.

  8. Deflecting RF cavity design for a recirculating linac based facility for ultrafast X-ray science (LUX)

    SciTech Connect

    Li, Derun; Corlett, J.N.

    2003-05-01

    We report on superconducting deflecting RF cavity designs for a Recirculating Linac Based Facility for Ultrafast X-ray Science (LUX) at Lawrence Berkeley National Laboratory. The deflecting cavities operate in the lowest dipole mode and are required to produce a temporal correlation within flat electron bunches, as needed for x-ray compression in crystal optics. Deflecting voltage of up to 8.5-MV is required at 3.9-GHz. We present a 7-cell cavity design in this paper. Seven such cavities are required to generate the 8.5 MV deflecting voltage. Longitudinal and transverse impedance from LOM (lower order mode) and HOM (higher order mode) are simulated using the MAFIA code. Short-range and long-range wakefield excited through these impedances are calculated. Beam loading effects of the deflecting mode and LOM modes are estimated. Q values of the LOM monopole modes in the cavity may need to be damped to be below 10{sup 4}-10{sup 5} levels in order to maintain the required energy spread.

  9. Use of Produced Water in Recirculating Cooling Systems at Power Generating Facilities

    SciTech Connect

    Kent Zammit; Michael N. DiFilippo

    2005-07-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. This deliverable describes possible test configurations for produced water demonstration projects at SJGS. The ability to host demonstration projects would enable the testing and advancement of promising produced water treatment technologies. Testing is described for two scenarios: Scenario 1--PNM builds a produced water treatment system at SJGS and incorporates planned and future demonstration projects into the design of the system. Scenario 2--PNM forestalls or decides not to install a produced water treatment system and would either conduct limited testing at SJGS (produced water would have to be delivered by tanker trucked) or at a salt water disposal facility (SWD). Each scenario would accommodate demonstration projects differently and these differences are discussed in this deliverable. PNM will host a demonstration test of water-conserving cooling technology--Wet Surface Air Cooling (WSAC) using cooling tower blowdown

  10. USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES

    SciTech Connect

    Michael N. DiFilippo

    2004-08-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Deliverable 2 focuses on transportation--the largest obstacle to produced water reuse in the San Juan Basin (the Basin). Most of the produced water in the Basin is stored in tanks at the well head and must be transported by truck to salt water disposal (SWD) facilities prior to injection. Produced water transportation requirements from the well head to SJGS and the availability of existing infrastructure to transport the water are discussed in this deliverable.

  11. RECIRCULATING ACCELERATION

    SciTech Connect

    BERG,J.S.; GARREN,A.A.; JOHNSTONE,C.

    2000-04-07

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous.

  12. USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES

    SciTech Connect

    Michael N. DiFilippo

    2004-08-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Deliverable 1 presents a general assessment of produced water generation in the San Juan Basin in Four Corners Area of New Mexico. Oil and gas production, produced water handling and disposal, and produced water quantities and chemistry are discussed. Legislative efforts to enable the use of this water at SJGS are also described.

  13. USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES

    SciTech Connect

    Kent Zammit; Michael N. DiFilippo

    2005-01-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Produced water is generated nationally as a byproduct of oil and gas production. Seven states generate 90 percent of the produced water in the continental US. About 37 percent of the sources documented in the US Geological Survey's (USGS) Produced Waters Database have a TDS of less than 30,000 mg/l. This is significant because produced water treatment for reuse in power plants was found to be very costly above 30,000 mg/l TDS. For the purposes of this report, produced water treatment was assessed using the technologies evaluated for the San Juan Generating Station (SJGS) in Deliverable 3, Treatment and Disposal Analysis. Also, a methodology was developed to readily estimate capital and operating costs for produced water treatment. Two examples are presented to show how the cost estimating methodology can be used to evaluate the cost of treatment of produced water at power plants close to oil and gas production.

  14. Demonstration of spray booth recirculation and partitioning -- Phase 2

    SciTech Connect

    Proffitt, D.; Clayton, R.K.; Ayer, J.

    1996-12-31

    Acurex Environmental was contracted by the US EPA to demonstrate an advanced pollution control cost reduction strategy at a US Marine Corps maintenance facility in Barstow, CA. One booth was modified and two new booths were built and manifolded into a single air pollution control device. This SERDP funded project grew out of previous studies by the EPA and DoD to evaluate and develop economic volatile organic compound (VOC) control technologies for painting facilities. This first application of partitioned recirculating booth in a high volume production environment fulfills a stated SERDP goal of transferring promising design concepts into reliable production applications.

  15. Evaluating Alternative Methodologies for Capturing As-Built Building Information Models (BIM) For Existing Facilities

    DTIC Science & Technology

    2010-08-01

    enables users to work with large point clouds, directly using AutoCAD tools and commands to create 2D drawings and 3D models. • Leica Cyclone...COBIE, 2D and 3D Technology Services/Vendors H. Survey Equipment Listing I. 2D Floor Plan Sample Plans 1 Evaluating Alternative Methodologies...overlain onto the point clouds and model, all of which are represented and navigable in 3D . • 2D Drawings. 2D drawings of facility floor plans

  16. Test facilities for investigation of combustion processes built at the Technical University of Lodz

    NASA Astrophysics Data System (ADS)

    Kowalewski, Grzegorz

    2001-04-01

    A number of fundamental research projects devoted to combustion processes have been carried out during the last years in the Department of Heat Technology and Refrigeration of the Technical University of Lodz, Poland. The investigations under various conditions of combustion have been conducted with the following research facilities and equipment: (1) a drop tower with 1.2 sec of microgravity conditions and ca. 1 m3 volume of the experimental package, (2) a test rig with a rotating cylindrical vessel (combustion chamber) up to 6000 rpm, (3) schlieren devices of 300 and 150 mm diameter, including a compact system for experiments in the drop tower, (4) several specialized chambers for combustion of gas- and two-phase mixtures, (5) high speed photography equipment including a 500 fps camera. Some of the experiments and facilities are presented on 27.5 min long video and mentioned in this paper in a form of the editing list of the video. Some examples of abstracts of particular specialized publications are quoted.

  17. Legionella and risk management in hospitals-A bibliographic research methodology for people responsible for built environment and facility management.

    PubMed

    Leiblein, Thomas W; Tucker, Matthew; Ashall, Mal; Lee, Susanne B; Gollnisch, Carsten; Hofer, Susanne

    2016-11-01

    An ongoing research project investigates the roles and duties of persons responsible for the built environment with respect to risk management of water systems and Legionella prevention from a facility management's perspective. Our literature review provides an approach for selecting and analysing abstracts of initially 177 journal articles, subjected to certain topic-specific inclusion and exclusion criteria. Different decision strategies of either logic 'yes/no', Boolean operators 'OR' or 'AND' and decisions for single counts or cumulative counts of the identified three principal keywords 'Legionella', 'hospital' and 'water', were completed. A final list of ten principal reference articles from 29 journals was compiled. It suggests that the interconnected perspective of water systems, Legionella and hospitals seems to be underrepresented in the field of the built environment and facility management. The term 'stakeholder', which would refer to decision-makers, was not found more than once. Our result is a useful summary of established sources of information on environmental Legionella research. The results can be helpful for those new to the topic.

  18. An influenza outbreak among pilgrims sleeping at a school without purpose built overnight accommodation facilities.

    PubMed

    Staff, Michael; Torres, Maria I

    2011-03-01

    This report describes a respiratory illness outbreak amongst a group of over 700 World Youth Day 2008 pilgrims staying at a basic accommodation venue for 1 week in July 2008. At this venue, 1 group of pilgrims was accommodated as a large group in a gymnasium and another group was sub-divided into smaller groups and accommodated in classrooms. Following confirmation of an influenza B outbreak by influenza point of care testing, control measures were promptly implemented. Isolation of cases, improved hand, respiratory and general hygiene, establishment of a mobile tent health facility at the accommodation venue, and the use of oseltamivir for the treatment of cases and prophylaxis of high risk contacts were implemented and the outbreak was brought under control within the week. Overall, 20% of pilgrims met the case definition for an influenza-like illness and 36% had an onset prior to arrival at the venue. The attack rate for those with onset while at the venue was significantly higher amongst pilgrims accommodated in the gymnasium than those staying in the classrooms. Findings from this study highlight the importance of early detection, the rapid implementation of control measures and appropriate prescribing of antivirals to manage influenza outbreaks. The findings also highlight the benefits of accommodating individuals in smaller groups within basic accommodation venues in the context of mass gatherings.

  19. Facility Designed and Built to Investigate the Combined Effects of Contaminant and Atomic Oxygen on a Light-Transmitting Surface

    NASA Technical Reports Server (NTRS)

    Sechkar, Edward A.; Stueber, Thomas J.; Tutledge, Sharon K.; Banks, Bruce A.

    2000-01-01

    A need exists to investigate changes in the transparency of a light-transmitting surface during simultaneous exposure to a contaminant and an atomic oxygen (AO) flux. This mechanism may be responsible for the degradation of the light-transmitting surfaces of both photovoltaic cells and photodiodes currently in use on many low-Earth-orbit spacecraft. To address this need, researchers from the Electro-Physics Branch of the NASA Glenn Research Center at Lewis Field built such a test system within their AO beam facility. This facility produces an effective AO flux of 1.4 10(exp 16) atoms/sq cm/sec and contains a three-axis positioning system that provides the motion capability necessary for test operations. During testing, a target surface is held directly within the AO beam and close to two contaminant effusion cells. The effusion cells are shielded from the AO beam, and the outgassing contaminant is constrained to move across the target surface when heat is applied to either of the reservoirs. A light source is periodically moved over the target surface, and the transmitted light intensity is checked with a photodiode located below the target. This light source is also periodically checked with a separate photodiode, which is protected from contamination and AO exposure, to allow adjustments necessary to maintain a consistent light intensity.

  20. A Recovery-Oriented Care Approach: Weighing the Pros and Cons of a Newly Built Mental Health Facility.

    PubMed

    Ahern, Catherine Clark; Bieling, Peter; McKinnon, Margaret C; McNeely, Heather E; Langstaff, Karen

    2016-02-01

    The current study adopted a recovery-oriented care approach by emphasizing patients' perspectives and experiences regarding changes to a newly built mental health facility. The inpatient entrance, or "portal," intended to balance the aims of recovery-oriented care with minimizing risk. A mixed-methods study of the portal's pros and cons was conducted, according to four themes: (a) autonomy versus inconvenience; (b) safety and security versus stigma; (c) unit door versus portal operating costs; and (d) privacy versus community integration. Focus groups engaging with patients (N = 39) indicated that the design effectively supported recovery-oriented care. Patients did not find the portal to be stigmatizing or triggering and valued the safety and privacy it created, and visitors also generally had a positive experience. Survey responses (N = 101) from portal users were also positive about the new design. The study findings suggest that the pros outweighed the cons of the new design. [Journal of Psychosocial Nursing and Mental Health Services, 54(2), 39-48.].

  1. Recirculating rotary gas compressor

    DOEpatents

    Weinbrecht, John F.

    1992-01-01

    A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

  2. Recirculating rotary gas compressor

    DOEpatents

    Weinbrecht, J.F.

    1992-02-25

    A positive displacement, recirculating Roots-type rotary gas compressor is described which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits which return compressed discharge gas to the compressor housing, where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor. 12 figs.

  3. An Image-Based Modeling Experience about Social Facilities, Built during the Fascist Period in Middle Italy

    NASA Astrophysics Data System (ADS)

    Rossi, D.

    2011-09-01

    The main focus of this article is to explain a teaching activity. This experience follows a research aimed to testing innovative systems for formal and digital analysis of architectural building. In particular, the field of investigation is the analytical drawing. An analytical draw allows to develope an interpretative and similar models of reality; these models are built using photomodeling techniques and are designed to re-write modern and contemporary architecture. The typology of the buildings surveyed belong to a cultural period, called Modern Movement, historically placed between the two world wars. The Modern Movement aimed to renew existing architectural principle and to a functional redefinition of the same one. In Italy these principles arrived during the Fascist period. Heritage made up of public social buildings (case del Balilla, G.I.L., recreation center...) built during the fascist period in middle Italy is remarkable for quantity and in many cases for architectural quality. This kind of buildings are composed using pure shapes: large cube (gyms) alternate with long rectangular block containing offices creates compositions made of big volumes and high towers. These features are perfectly suited to the needs of a surveying process by photomodeling where the role of photography is central and where there is the need to identify certain and easily distinguishable points on all picture, leaning on the edges of the volume or lininig on the texture discontinuity. The goal is the documentation to preserve and to develop buildings and urban complexes of modern architecture, directed to encourage an artistic preservation.

  4. Recirculating Air Filtration Significantly Reduces Exposure to Airborne Nanoparticles

    PubMed Central

    Pui, David Y.H.; Qi, Chaolong; Stanley, Nick; Oberdörster, Günter; Maynard, Andrew

    2008-01-01

    Background Airborne nanoparticles from vehicle emissions have been associated with adverse effects in people with pulmonary and cardiovascular disease, and toxicologic studies have shown that nanoparticles can be more hazardous than their larger-scale counterparts. Recirculating air filtration in automobiles and houses may provide a low-cost solution to reducing exposures in many cases, thus reducing possible health risks. Objectives We investigated the effectiveness of recirculating air filtration on reducing exposure to incidental and intentionally produced airborne nanoparticles under two scenarios while driving in traffic, and while generating nanomaterials using gas-phase synthesis. Methods We tested the recirculating air filtration in two commercial vehicles when driving in traffic, as well as in a nonventilation room with a nanoparticle generator, simulating a nanomaterial production facility. We also measured the time-resolved aerosol size distribution during the in-car recirculation to investigate how recirculating air filtration affects particles of different sizes. We developed a recirculation model to describe the aerosol concentration change during recirculation. Results The use of inexpensive, low-efficiency filters in recirculation systems is shown to reduce nanoparticle concentrations to below levels found in a typical office within 3 min while driving through heavy traffic, and within 20 min in a simulated nanomaterial production facility. Conclusions Development and application of this technology could lead to significant reductions in airborne nanoparticle exposure, reducing possible risks to health and providing solutions for generating nanomaterials safely. PMID:18629306

  5. Recirculating air filtration significantly reduces exposure to airborne nanoparticles.

    PubMed

    Pui, David Y H; Qi, Chaolong; Stanley, Nick; Oberdörster, Günter; Maynard, Andrew

    2008-07-01

    Airborne nanoparticles from vehicle emissions have been associated with adverse effects in people with pulmonary and cardiovascular disease, and toxicologic studies have shown that nanoparticles can be more hazardous than their larger-scale counterparts. Recirculating air filtration in automobiles and houses may provide a low-cost solution to reducing exposures in many cases, thus reducing possible health risks. We investigated the effectiveness of recirculating air filtration on reducing exposure to incidental and intentionally produced airborne nanoparticles under two scenarios: while driving in traffic, and while generating nanomaterials using gas-phase synthesis. We tested the recirculating air filtration in two commercial vehicles when driving in traffic, as well as in a nonventilation room with a nanoparticle generator, simulating a nanomaterial production facility. We also measured the time-resolved aerosol size distribution during the in-car recirculation to investigate how recirculating air filtration affects particles of different sizes. We developed a recirculation model to describe the aerosol concentration change during recirculation. The use of inexpensive, low-efficiency filters in recirculation systems is shown to reduce nanoparticle concentrations to below levels found in a typical office within 3 min while driving through heavy traffic, and within 20 min in a simulated nanomaterial production facility. Development and application of this technology could lead to significant reductions in airborne nanoparticle exposure, reducing possible risks to health and providing solutions for generating nanomaterials safely.

  6. The impact of recirculating industrial air on aircraft painting operations.

    PubMed

    LaPuma, P T; Bolch, W E

    1999-10-01

    The 1990 Clean Air Act Amendments resulted in new environmental regulations for hazardous air pollutants. Industries such as painting facilities may have to treat large volumes of air, which increases the cost of an air control system. Recirculating a portion of the air back into the facility is an option to reduce the amount of air to be treated. The authors of this study developed a computer model written in Microsoft Excel 97 to analyze the impact of recirculation on worker safety and compliance costs. The model has a chemical database with over 1300 chemicals. The model will predict indoor air concentrations using mass balance calculations and results are compared to occupational exposure limits. A case study is performed on a C-130 aircraft painting facility at Hill Air Force Base, Utah. The model predicts strontium chromate concentrations found in primer paints will reach 1000 times the exposure limit. Strontium chromate and other solid particulates are nearly unaffected by recirculation because the air is filtered during recirculation. The next highest chemical, hexamethylene diisocyanate, increases from 2.6 to 10.5 times the exposure limit at 0 percent and 75 percent recirculation, respectively. Due to the level of respiratory protection required for the strontium chromate, workers are well protected from the modest increases in concentrations caused by recirculating 75 percent of the air. The initial cost of an air control system is $4.5 million with no recirculation and $1.8 million at 75 percent recirculation. The model is an excellent tool to evaluate air control options with a focus on worker safety. In the case study, the model highlights strontium chromate primers as good candidates for substitution. The model shows that recirculating 75 percent of the air at the Hill painting facility has a negligible impact on safety and could save $2.7 million on the initial expenses of a thermal treatment system.

  7. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, John F.

    1989-01-01

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

  8. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, J.F.

    1989-08-22

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

  9. Preoperational test report, recirculation condenser cooling systems

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  10. Preoperational test report, recirculation ventilation systems

    SciTech Connect

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  11. Combustion-gas recirculation system

    DOEpatents

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  12. Nuclear reactors built, being built, or planned 1993

    SciTech Connect

    Not Available

    1993-08-01

    Nuclear Reactors Built, Being Built, or Planned contains unclassified information about facilities built, being built, or planned in the United States for domestic use or export as of December 31, 1993. The Office of Scientific and Technical Information, US Department of Energy, gathers this information annually from Washington headquarters and field offices of DOE; from the US Nuclear Regulatory Commission (NRC); from the US reactor manufacturers who are the principal nuclear embassies; and from foreign governmental nuclear departments. The book consists of three divisions, as follows: (1) a commercial reactor locator map and tables of the characteristic and statistical data that follow; a table of abbreviations; (2) tables of data for reactors operating, being built, or planned; and (3) tables of data for reactors that have been shut down permanently or dismantled. The reactors are subdivided into the following parts: civilian, production, military, export, and critical assembly.

  13. Steering algorithms for a small recirculating heavy-ion accelerator

    SciTech Connect

    Sharp, W.M.; Grote, D.P.; Hemandez, G.W.

    1997-11-07

    Beam-steering algorithms are proposed for a small recirculating induction accelerator being built at the Lawrence Livermore National Laboratory. The principal problem is that the transverse position and velocity of the beam must be inferred from capacitive position monitors, and this determination is complicated by the limited probe resolution and by the lattice errors within steering modules. The fluid/envelope code CIRCE is used to evaluate these algorithms.

  14. DOGBONE GEOMETRY FOR RECIRCULATING ACCELERATORS.

    SciTech Connect

    BERG,J.S.; JOHNSTONE,C.; SUMMERS,D.

    2001-06-18

    Most scenarios for accelerating muons require recirculating acceleration. A racetrack shape for the accelerator requires particles with lower energy in early passes to traverse almost the same length of arc as particles with the highest energy. This extra arc length may lead to excess decays and excess cost. Changing the geometry to a dogbone shape, where there is a single linac and the beam turns completely around at the end of the linac, returning to the same end of the linac from which it exited, addresses this problem. In this design, the arc lengths can be proportional to the particle's momentum. This paper proposes an approximate cost model for a recirculating accelerator, attempts to make cost-optimized designs for both racetrack and dogbone geometries, and demonstrates that the dogbone geometry does appear to be more cost effective.

  15. Recirculated and Energy Recovered Linacs

    SciTech Connect

    Geoffrey Krafft

    2003-05-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams from an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible from either a conventional linac, or from storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend from high power free-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  16. A research facility for habitation questions to be built at the German Aerospace Center in Cologne: future challenges of Space medicine.

    PubMed

    Koch, B; Gerzer, R

    2008-08-01

    For long term habitation in space and for living on Moon and Mars, many questions still need to be resolved. Such habitation questions include prevention of and rehabilitation from negative effects of weightlessness that are, in many instances, comparable to problems of aging people on Earth as well as of patients during and recovery from long term stays in bed. Therefore the DLR Institute of Aerospace Medicine has designed a concept for a research facility that will make it possible to join space research directly with terrestrial applications. From a strategic point of view, one major emphasis of :envihab is to form a closely interrelated network of scientists and the industry and the public. The project has been in the planning phase for several years. After an international architectural contest, the winning concept was selected in 2007 by a Jury with ESA participation.

  17. A research facility for habitation questions to be built at the German Aerospace Center in Cologne: future challenges of Space medicine

    PubMed Central

    Koch, B; Gerzer, R

    2008-01-01

    For long term habitation in space and for living on Moon and Mars, many questions still need to be resolved. Such habitation questions include prevention of and rehabilitation from negative effects of weightlessness that are, in many instances, comparable to problems of aging people on Earth as well as of patients during and recovery from long term stays in bed. Therefore the DLR Institute of Aerospace Medicine has designed a concept for a research facility that will make it possible to join space research directly with terrestrial applications. From a strategic point of view, one major emphasis of :envihab is to form a closely interrelated network of scientists and the industry and the public. The project has been in the planning phase for several years. After an international architectural contest, the winning concept was selected in 2007 by a Jury with ESA participation. PMID:19048099

  18. The dynamics of the Vietnam summer recirculation

    NASA Astrophysics Data System (ADS)

    Bayler, E.; Liu, Z.

    2003-04-01

    Using TOPEX/Poseidon altimetry, a seasonal pair of recirculations in the South China Sea along the coast of Vietnam is identified in the sea surface height anomalies (SSHA). The dynamics of this recirculation system are further studied in a numerical model. Forced by monsoon winds, the ocean circulation in the South China Sea reverses the western boundary current along Vietnam with each shift in monsoon regime. During the summer southwest monsoon, an anticyclonic recirculation cell develops near 12^o North 111^o East, consistent with large-scale recirculation theory and is labeled the Vietnam Summer Recirculation (VSR). The subsequent transition to the winter northeast monsoon regime destroys this recirculation cell. Employing high-resolution 1.5-layer and 2.0-layer numerical models, we demonstrate the applicability of large-scale recirculation dynamics to the deep basin of the South China Sea, specifically showing that the gyre-scale circulation governs the development of the VSR. This study also explores the significant role of topography in determining the location and magnitude of the recirculation cell. The destruction of this recirculation by the migrating monsoon winds each autumn is also modeled. The monsoon wind forcing highlights the driving role of gyre-scale dynamics in the formation and destruction of the Vietnam Summer Recirculation.

  19. Nuclear reactors built, being built, or planned, 1991

    SciTech Connect

    Simpson, B.

    1992-07-01

    This document contains unclassified information about facilities built, being built, or planned in the United States for domestic use or export as of December 31, 1991. The book is divided into three major sections: Section 1 consists of a reactor locator map and reactor tables; Section 2 includes nuclear reactors that are operating, being built, or planned; and Section 3 includes reactors that have been shut down permanently or dismantled. Sections 2 and 3 contain the following classification of reactors: Civilian, Production, Military, Export, and Critical Assembly. Export reactor refers to a reactor for which the principal nuclear contractor is an American company -- working either independently or in cooperation with a foreign company (Part 4, in each section). Critical assembly refers to an assembly of fuel and assembly of fuel and moderator that requires an external source of neutrons to initiate and maintain fission. A critical assembly is used for experimental measurements (Part 5).

  20. Nuclear reactors built, being built, or planned 1996

    SciTech Connect

    1997-08-01

    This publication contains unclassified information about facilities, built, being built, or planned in the United States for domestic use or export as of December 31, 1996. The Office of Scientific and Technical Information, U.S. Department of Energy, gathers this information annually from Washington headquarters, and field offices of DOE; from the U.S. Nuclear Regulatory Commission (NRC); from the U. S. reactor manufacturers who are the principal nuclear contractors for foreign reactor locations; from U.S. and foreign embassies; and from foreign governmental nuclear departments. The book consists of three divisions, as follows: (1) a commercial reactor locator map and tables of the characteristic and statistical data that follow; a table of abbreviations; (2) tables of data for reactors operating, being built, or planned; and (3) tables of data for reactors that have been shut down permanently or dismantled.

  1. New design incinerator being built

    SciTech Connect

    Not Available

    1980-09-01

    A $14 million garbage-burning facility is being built by Reedy Creek Utilities Co. in cooperation with DOE at Lake Buena Vista, Fla., on the edge of Walt Disney World. The nation's first large-volume slagging pyrolysis incinerator will burn municipal waste in a more beneficial way and supply 15% of the amusement park's energy demands. By studying the new incinerators slag-producing capabilities, engineers hope to design similar facilities for isolating low-level nuclear wastes in inert, rocklike slag.

  2. Introduction of electrodehydrators with built-in jet mixers

    SciTech Connect

    Gershuni, S.S.; Baimbetov, A.M.; Idrisova, T.S.; Makhov, A.F.

    1985-09-01

    This paper describes an effective technique of crude oil desalting which is recirculation of water within the electrodehydrator by means of built-in jet mixers. Vertical electrodehydrators with built-in jet mixers have been tested and approved at the Novo-Ufa refinery. Design and operation of the vessel is described. Results from analyses of the oil during the test period are summarized. Retrofitting of electrodehydrators with built-in jet mixers proved increased capacity and the consumption of water and electric power in desalting was cut in half while oil loss in the electric desalting units was reduced substantially.

  3. The development of a TESLA recirculator with superconducting accelerating structures in Ukraine

    NASA Astrophysics Data System (ADS)

    Guk, I. S.; Dovbnya, A. N.

    2008-12-01

    The recirculator project, which is to be built at the National Science Center, Kharkov Institute of Physics and Technology (NSC KIPT), is presented. The basic solutions incorporated in the design are given. The TESLA superconducting section is chosen as the accelerating structure of an accelerating complex.

  4. Na+ recirculation and isosmotic transport.

    PubMed

    Larsen, E H; Møbjerg, N

    2006-01-01

    The Na(+) recirculation theory for solute-coupled fluid absorption is an expansion of the local osmosis concept introduced by Curran and analyzed by Diamond & Bossert. Based on studies on small intestine the theory assumes that the observed recirculation of Na(+) serves regulation of the osmolarity of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal NaCl by sucrose as well as the linear dependence of volume absorption on luminal NaCl concentration. Analysis of solvent drag on Na(+) in tight junctions provides explanation for the surprisingly high metabolic efficiency of Na(+) reabsorption. The model predicts and explains low metabolic efficiency in diluted external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and < or = 1 mOsm in proximal tubule. Truly isosmotic transport demands a Na(+) recirculation of 50-70% in small intestine but might be barely measurable in proximal tubule. The model fails to reproduce a certain type of observations: The reduced volume absorption at transepithelial osmotic equilibrium in AQP1 knockout mice, and the stimulated water absorption by gallbladder in diluted external solutions. Thus, it indicates cellular regulation of apical Na(+) uptake, which is not included in the mathematical treatment.

  5. Recirculation in multiple wave conversions

    SciTech Connect

    Kaufman, A. N.; Brizard, A.J.; Kaufman, A.N.; Tracy, E.R.

    2008-07-30

    A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.

  6. Gas recirculator for acyclic machines

    NASA Astrophysics Data System (ADS)

    Balsa, T. F.

    1985-05-01

    The present invention relates to acyclic machines of the type using liquid metal collectors, and more particularly to an improvement for retaining the liquid metal in such machines. Radial type acyclic motors and generators generally include a metallic disk rotor rotating on a shaft between electromagnetic stator poles excited by field coils wound concentric with the shaft. Instead of solid brush, current collectors at the rotor periphery, liquid metal collectors are sometimes used to close the electrical current loop between the shaft and the rotor, and an inert pressurized cover gas fills the gaps between the rotating components and the stationary housing. A cover has recirculator in an acyclic generator having liquid metal collectors for reducing entrainment of the liquid metal in the gas. Radial passages in the stator housing provide natural recirculating paths for the cover gas to flow radially outward along the sides of the rotor and return inwardly through the passages. Scoops or lips located inward of the liquid metal collector divert the outward gas flow into the passages to minimize contact of the gas with the liquid metal.

  7. Recirculation in venovenous extracorporeal membrane oxygenation.

    PubMed

    Xie, Ashleigh; Yan, Tristan D; Forrest, Paul

    2016-12-01

    Despite the increasing use of venovenous extracorporeal membrane oxygenation (ECMO) to treat severe respiratory failure, recirculation remains a common complication that may result in severe hypoxemia and end-organ damage. The present review, therefore, examines updated evidence for the causes, measurement, and management of recirculation. Six electronic databases were searched from their dates of inception to January 2016, and 38 relevant studies were selected for analysis. This review revealed that, currently, recirculation is typically calculated from measurement of blood oxygen saturations, although limited evidence suggests that oxygen content may provide a more accurate measure. Dilutional ultrasound may play an additional role in dynamic quantitative monitoring of recirculation, but further human studies are required to validate its clinical use. Although cannula configuration appears to be a key contributor to recirculation in addition to factors such as ECMO flow rate, there are insufficient comparative clinical studies to recommend an optimal cannulation technique for minimizing recirculation. Existing evidence suggests that the dual-lumen cannula may have a low recirculation fraction, but only if correctly positioned. This review underscores the need for more robust clinical and laboratory studies to effectively evaluate and address the persistent problem of recirculation.

  8. Space hands-on universe telescope and orbiting wide-angle light-collector telescope to be built on the Japanese experiment module exposure facility of the international space station

    NASA Astrophysics Data System (ADS)

    Takahashi, Yoshiyuki; Ebisuzaki, Toshikazu; Pennypacker, Carlton

    1999-01-01

    A concept study to build great observatories on, and deploy from, the ISS is presented. Use of the ISS infra-structure including robotic arms and astronauts' EVA would permit a construction of very large optical telescopes. We envisage that the second phase of the ISS after its initial construction can landmark a new era for both ISS and Space Sciences. Ultimately, this study would plan a 10-or 20-meter class space telescope. For its first step, we envisioned an immediate extension of the Exposed Facility of ISS for building a ``Work-bench'' for this purpose. Initial activities can begin with two modest-sized telescopes soon after the ISS construction. These early missions being studied are space Hands-On Universe Telescope (SHOUT) and Orbiting Wide-angle Light-collector (OWL). SHOUT is a 1-m telescope for science education. It will be built and adjusted on the exposure module of the Japanese Experiment Module (JEM) of the International Space Station by using a robotic arm and the EVA of astronauts. We also seek the possibility to release it from ISS after its perfection on orbit, so that it is free from the vibrations and gas contaminations on and around the ISS. SHOUT is an engineering prototype of 10-m Space Telescope (Space SUBARU Telescope). It would be scaled from the Space-SUBARU telescope so that the testing with the SHOUT would warrant the required specifications for the 10-meter Space-SUBARU construction on the ISS. The goal of the test with the SHOUT is to warrant a spatial resolution of 0.01 arc-seconds using the active/adaptive optics. It will test the following three major engineering challenges: (1) active/adaptive optics in space; (2) building of large structures by astronauts; and (3) release of a spacecraft from ISS to a free-flying orbit. The present feasibility study for the next generation great observatories that are to be built on the JEM Exposure Facility (EF) has been already funded by the Japan Space Forum, under the auspices of the

  9. Space hands-on universe telescope and orbiting wide-angle light-collector telescope to be built on the Japanese experiment module exposure facility of the international space station

    SciTech Connect

    Takahashi, Y.; Ebisuzaki, T.; Pennypacker, C.

    1999-01-01

    A concept study to build great observatories on, and deploy from, the ISS is presented. Use of the ISS infra-structure including robotic arms and astronauts{close_quote} EVA would permit a construction of very large optical telescopes. We envisage that the second phase of the ISS after its initial construction can landmark a new era for both ISS and Space Sciences. Ultimately, this study would plan a 10-or 20-meter class space telescope. For its first step, we envisioned an immediate extension of the Exposed Facility of ISS for building a {open_quotes}Work-bench{close_quotes} for this purpose. Initial activities can begin with two modest-sized telescopes soon after the ISS construction. These early missions being studied are space Hands-On Universe Telescope (SHOUT) and Orbiting Wide-angle Light-collector (OWL). SHOUT is a 1-m telescope for science education. It will be built and adjusted on the exposure module of the Japanese Experiment Module (JEM) of the International Space Station by using a robotic arm and the EVA of astronauts. We also seek the possibility to release it from ISS after its perfection on orbit, so that it is free from the vibrations and gas contaminations on and around the ISS. SHOUT is an engineering prototype of 10-m Space Telescope (Space SUBARU Telescope). It would be scaled from the Space-SUBARU telescope so that the testing with the SHOUT would warrant the required specifications for the 10-meter Space-SUBARU construction on the ISS. The goal of the test with the SHOUT is to warrant a spatial resolution of 0.01 arc-seconds using the active/adaptive optics. It will test the following three major engineering challenges: (1) active/adaptive optics in space; (2) building of large structures by astronauts; and (3) release of a spacecraft from ISS to a free-flying orbit. The present feasibility study for the next generation great observatories that are to be built on the JEM Exposure Facility (EF) has been already funded by the Japan Space

  10. Lattice Design for the LHEC Recirculating Linac

    SciTech Connect

    Sun, Yipeng; Eide, Anders; Zimmermann, Frank; Adolphsen, Chris; /SLAC

    2011-05-20

    In this paper, we present a lattice design for the Large Hadron Electron Collider (LHeC) recirculating linac. The recirculating linac consists of one roughly 3-km long linac hosting superconducting RF (SRF) accelerating cavities, two arcs and one transfer line for the recirculation. In two passes through a pulsed SRF linac the electron beam can get a maximum energy of 140 GeV. Alternatively, in the Energy Recovery Linac (ERL) option the beam passes through a CW linac four times (two passes for acceleration and two for deceleration) for a maximum energy of 60 GeV.

  11. TANK MIXING STUDY WITH FLOW RECIRCULATION

    SciTech Connect

    Lee, S.

    2014-06-25

    The primary objective of this work is to quantify the mixing time when two miscible fluids are mixed by one recirculation pump and to evaluate adequacy of 2.5 hours of pump recirculation to be considered well mixed in SRS tanks, JT-71/72. The work scope described here consists of two modeling analyses. They are the steady state flow pattern analysis during pump recirculation operation of the tank liquid and transient species transport calculations based on the initial steady state flow patterns. The modeling calculations for the mixing time are performed by using the 99% homogeneity criterion for the entire domain of the tank contents.

  12. Nuclear reactors built, being built, or planned, 1994

    SciTech Connect

    1995-07-01

    This document contains unclassified information about facilities built, being built, or planned in the United States for domestic use or export as of December 31, 1994. The Office of Scientific and Technical Information, US Department of Energy, gathers this information annually from Washington headquarters and field offices of DOE; from the US Nuclear Regulatory Commission (NRC); from the US reactor manufacturers who are the principal nuclear contractors for foreign reactor locations; from US and foreign embassies; and from foreign governmental nuclear departments. The book consists of three divisions, as follows: a commercial reactor locator map and tables of the characteristic and statistical data that follow; a table of abbreviations; tables of data for reactors operating, being built, or planned; and tables of data for reactors that have been shut down permanently or dismantled. The reactors are subdivided into the following parts: Civilian, Production, Military, Export, and Critical Assembly. Export reactor refers to a reactor for which the principal nuclear contractor is a US company -- working either independently or in cooperation with a foreign company (Part 4). Critical assembly refers to an assembly of fuel and moderator that requires an external source of neutrons to initiate and maintain fission. A critical assembly is used for experimental measurements (Part 5).

  13. Nuclear reactors built, being built, or planned: 1995

    SciTech Connect

    1996-08-01

    This report contains unclassified information about facilities built, being built, or planned in the US for domestic use or export as of December 31, 1995. The Office of Scientific and Technical Information, US Department of Energy, gathers this information annually from Washington headquarters and field offices of DOE; from the US Nuclear Regulatory Commission (NRC); from the US reactor manufacturers who are the principal nuclear contractors for foreign reactor locations; from US and foreign embassies; and from foreign governmental nuclear departments. The book consists of three divisions, as follows: (1) a commercial reactor locator map and tables of the characteristic and statistical data that follow; a table of abbreviations; (2) tables of data for reactors operating, being built, or planned; and (3) tables of data for reactors that have been shut down permanently or dismantled. The reactors are subdivided into the following parts: Civilian, Production, Military, Export, and Critical Assembly. Export reactor refers to a reactor for which the principal nuclear contractor is a US company--working either independently or in cooperation with a foreign company (Part 4). Critical assembly refers to an assembly of fuel and moderator that requires an external source of neutrons to initiate and maintain fission. A critical assembly is used for experimental measurements (Part 5).

  14. Facilities

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An expansion of medical data collection facilities was necessary to implement the Extended Duration Orbiter Medical Project (EDOMP). The primary objective of the EDOMP was to ensure the capability of crew members to reenter the Earth's atmosphere, land, and egress safely following a 16-day flight. Therefore, access to crew members as soon as possible after landing was crucial for most data collection activities. Also, with the advent of EDOMP, the quantity of investigations increased such that the landing day maximum data collection time increased accordingly from two hours to four hours. The preflight and postflight testing facilities at the Johnson Space Center (JSC) required only some additional testing equipment and minor modifications to the existing laboratories in order to fulfill EDOMP requirements. Necessary modifications at the landing sites were much more extensive.

  15. A recirculating stream aquarium for ecological studies.

    Treesearch

    Gordon H. Reeves; Fred H. Everest; Carl E. McLemore

    1983-01-01

    Investigations of the ecological behavior of fishes often require studies in both natural and artificial stream environments. We describe a large, recirculating stream aquarium and its controls, constructed for ecological studies at the Forestry Sciences Laboratory in Corvallis.

  16. Three-dimensional modelling of leachate recirculation using vertical wells in bioreactor landfills.

    PubMed

    Feng, Shi-Jin; Chen, Zheng-Wei; Cao, Ben-Yi

    2016-12-01

    Bioreactor landfills use leachate recirculation to enhance the biodegradation of municipal solid waste and accelerate landfill stabilisation, which can provide significant environmental and economic benefits. Vertical wells are operated as a major method for leachate recirculation systems. The objectives of this article are to analyse the leachate migration in bioreactor landfills using vertical wells and to offer theoretical basis for the design of leachate recirculation systems. A three-dimensional numerical model was built using FLAC-3D, and this model can consider the saturated and unsaturated flow of leachate within anisotropic waste to reflect the actual conditions. First, main influence factors of leachate migration were analysed, including the vertical well height, hydraulic conductivity, and anisotropic coefficient, in a single-well recirculation system. Then, the effects of different configurations of a group-well system were studied and the optimal well spacing was obtained. Some key design parameters (e.g. the recirculation flow rate, volume of impact zone, radius of impact zone and time to reach steady state) were also evaluated. The results show that the hydraulic conductivity has a great impact on the optimal height of vertical wells and uniform configuration is the best option in terms of both volume of impact zone and time to reach steady state. © The Author(s) 2016.

  17. Recirculating cross-correlation detector

    DOEpatents

    Andrews, W.H. Jr.; Roberts, M.J.

    1985-01-18

    A digital cross-correlation detector is provided in which two time-varying signals are correlated by repetitively comparing data samples stored in digital form to detect correlation between the two signals. The signals are sampled at a selected rate converted to digital form, and stored in separate locations in separate memories. When the memories are filled, the data samples from each memory are first fed word-by-word through a multiplier and summing circuit and each result is compared to the last in a peak memory circuit and if larger than the last is retained in the peak memory. Then the address line to leading signal memory is offset by one byte to affect one sample period delay of a known amount in that memory and the data in the two memories are then multiplied word-by-word once again and summed. If a new result is larger than a former sum, it is saved in the peak memory together with the time delay. The recirculating process continues with the address of the one memory being offset one additional byte each cycle until the address is shifted through the length of the memory. The correlation between the two signals is indicated by the peak signal stored in the peak memory together with the delay time at which the peak occurred. The circuit is faster and considerably less expensive than comparable accuracy correlation detectors.

  18. Assessing peracetic acid as a means to control post-vaccination Saprolegniasis in Atlantic salmon Salmo salar parr in recirculation aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    Land-based closed containment facilities, utilizing recirculation aquaculture system (RAS) technologies, can reduce or eliminate the introduction of obligate fish pathogens. Regardless, the presence of opportunistic pathogens must be assumed, and these agents can cause disease during unfavorable con...

  19. Recirculating industrial air: The impact on air compliance and workers` safety case study -- Hill Air Force Base C-130 painting operations. Final report, September 1996--July 1998

    SciTech Connect

    LaPuma, P.T.

    1998-07-20

    Recent Clean Air Act regulations require industries, including aircraft painting facilities, to capture volatile organic compound (VOC) emissions. Because aircraft painting contaminates large airflows with traces of VOCs, conventional air control systems would be prohibitively expensive to apply. Recirculating a portion of the air back into the facility is an option to reduce the amount of air to be treated. A computer model is presented that will calculate air control costs and chemical concentrations at selected recirculation levels. Air concentrations are compared to occupational exposure limits (OELs) to analyze worker safety. The model has a chemical database containing over 1300 chemicals. A case study has been performed on a C-130 aircraft painting facility at Hill Air Force Base, Utah. The model predicts strontium chromate concentrations during application of primer paints will reach 1000 times the OEL, and that the concentration will increase by only 1 or 2% at 90% recirculation. Exposures to strontium chromate and other particulate contaminants are affected only slightly by recirculation because airborne solids are removed efficiently when the air is filtered prior to recirculation. The respiratory protection required for the strontium chromate adequately protects workers from increased concentrations of volatile chemicals, which are caused by recirculation. The model demonstrates that recirculating 75% of the air at the Hill AFB facility has a negligible impact on safety and could save $2.7 million on the initial expenses of a VOC control system.

  20. Flume simulation of sedimentation in recirculating flow

    SciTech Connect

    Schmidt, J.C. ); Rubin, D.M. ); Ikeda, H. )

    1990-05-01

    A 4-m-wide flume at the University of Tsukuba Environmental Research Center was used to simulate flow conditions near debris fans in bedrock gorges. Flow was constricted to 2 m by a semicircular obstruction. During the authors experiments (discharge = 600 L/sec; Froude number of constricted flow = 1) a zone of recirculating current extended 25-30 m downstream from the separation point at the constriction. The pattern and velocity of surface flow was determined using time-lapse photography; subsurface velocity was measured with a two-dimensional electromagnetic current meter. During 32-hr of run time, a fine, very coarse sand mixture was fed into the flow at a rate between 0.5-1 kg/sec. Oscillation ripples developed beneath the separation surface that bounds the recirculation zone, and upstream-migrating dunes and ripples developed within the recirculation zone upstream from the reattachment point. A mid-channel expansion bar was deposited downstream from the reattachment point. Sedimentation within the recirculation zone continued by vertical aggradation and by upstream migration of dunes and ripples. Sediments within the recirculation zone were areally sorted with the finest sediment deposited near the separation point. These patterns are consistent with field observations of bars along the Colorado River in the Grand Canyon.

  1. NGL recovery increase through natural gasoline recirculation

    SciTech Connect

    Rivas M., M.; Bracho, J.L.; Murray, J.

    1997-12-31

    Given that the gas being processed in the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3) of Lagoven, S.A., an operating affiliate of Petroleos de Venezuela, S.A. has become learner through time, current production of natural gas liquids (NGL) and plant efficiency are significantly lower, compared to design and first obtained values. In this sense and aimed at increasing propane production, an optimization study on condensate stream recirculation and absorber installation was carried out to affect the process equilibrium constants thereby obtaining deeper extraction. Recirculation streams options were recirculation of natural gasoline obtained from the downstream fractionation process and recirculation of a conditioned, unfractionated, deethanized condensate stream. From the study, the natural gasoline recirculation scheme was determined to be the most efficient NGL recovery process. Accordingly, Lagoven, S.A. has undertaken a project to carry out this optimization scheme in PCTJ-2 and PCTJ-3. Construction stages are currently underway with completion scheduled at the end of 1997.

  2. Small recirculating filters for nitrogen reduction.

    PubMed

    Piluk, R J; Byers, B R

    2001-09-01

    Concerned about the negative impacts of nitrogen loading from septic systems on the Chesapeake Bay watershed, Maryland's Anne Arundel County Health Department has pioneered the use of small recirculating sand filters to reduce nitrogen in effluent from residential septic systems. Recirculating sand filters can reduce the total nitrogen in septic-tank effluent by up to 70 percent. Years of experience and the county's participation in the National Onsite Demonstration Project have led to modifications that make the filters more acceptable to homeowners. Use of alternative media, changes in flow patterns, and homeowner education have increased acceptance by homeowners.

  3. Peach bottom recirculation piping replacement ALARA program

    SciTech Connect

    Englesson, G.A.; Hilsmeier, A.E.; Mann, B.J.

    1986-01-01

    In late 1983, Philadelphia Electric Company (PECo) began detailed planning to replace the recirculation, residual heat removal, and part of the reactor water cleanup piping of the Peach Bottom Unit 2 reactor. Included in this work was an estimate of the collective exposure expected during piping replacement. That initial estimate, 1945 man-rem, is compared with the actual collective dose incurred during the piping replacement program. Also included are the exposures incurred during two additional tasks (safe end replacement and recirculation pump disassembly and decontamination) not considered in the initial estimate.

  4. Engineering systems designs for a recirculating heavy ion induction accelerator

    SciTech Connect

    Newton, M.A.; Barnard, J.J.; Reginato, L.L.; Yu, S.S.

    1991-05-01

    Recirculating heavy ion induction accelerators are being investigated as possible drivers for heavy ion fusion. Part of this investigation has included the generation of a conceptual design for a recirculator system. This paper will describe the overall engineering conceptual design of this recirculator, including discussions of the dipole magnet system, the superconducting quadrupole system and the beam acceleration system. Major engineering issues, evaluation of feasibility, and cost tradeoffs of the complete recirculator system will be presented and discussed. 5 refs., 4 figs.

  5. Nitrogen removal in recirculated duckweed ponds system.

    PubMed

    Benjawan, L; Koottatep, T

    2007-01-01

    Duckweed-based ponds (DWBPs) have the potential for nitrogen (N) removal from wastewater; however, operational problems such as duckweed die-off regularly occur. In this study, effluent recirculation was applied to the DWBPs to solve the above problem as well as to investigate N removal mechanisms. Two pilot scale recirculated DWBPs were employed to treat municipal wastewater. The average removal efficiencies for TN, TKN and NH4-N were 75%, 89% and 92%, respectively at TN loading of 1.3 g/m2.d and were 73%, 74% and 76%, respectively at TN loading of 3.3 g/m2.d. The effluent of the system under both operational conditions had stable quality and met the effluent standard. Duckweed die-off was not observed during the study, which proves the system stability and effluent recirculation which is thought to be a reason. N-mass balance revealed that nitrification-denitrification and duckweed uptake play major roles in these recirculated DWBPs. The rates of nitrification-denitrification were increased as TN loading was higher, which might be an influence from an abundance of N and a suitable condition. The rates of N uptake by duckweed were found similar and did not depend on the higher TN loading applied, as the duckweed has limited capacity to assimilate it.

  6. Recirculating sprayer for fiber-filled paints

    NASA Technical Reports Server (NTRS)

    Major, R. K.

    1980-01-01

    Recirculating paint sprayer applies spray of coarse filler in highly volatile solvent. Sprayer was developed for applying insulation material containing epxoy resin, glass fibers, and inert fillers suspended in chlorinated solvents. Sprayer resists abrasive action of fiberglass filler and chemical activity of solvent. Pump and position ensure more uniform pressure at spray gun without backpressure regulator, which tended to clog in old sprayer.

  7. Recirculation as a Form of Conservation.

    ERIC Educational Resources Information Center

    Gordon, Jeffrey J.

    1982-01-01

    Discusses nine forms of conservation practices: sustained yield, repair, careful use, greater efficiency, lower consumption, doing without, substitution, new resources, and recycling. Suggests recirculation (saving goods from discard and from being broken down in a new manufacturing stage) as a 10th form of conservation practice. (Author/JN)

  8. Production of cobia in recirculating systems

    USDA-ARS?s Scientific Manuscript database

    Only limited information exists with respect to rearing juvenile cobia Rachycentron canadum to stocker and marketable sizes using recirculating aquaculture systems (RAS). To investigate this topic, two rearing trials were conducted using commercial scale RAS. In Trial 1, juvenile cobia (29 g) we...

  9. 21 CFR 880.5045 - Medical recirculating air cleaner.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical recirculating air cleaner. 880.5045... Therapeutic Devices § 880.5045 Medical recirculating air cleaner. (a) Identification. A medical recirculating air cleaner is a device used to remove particles from the air for medical purposes. The device...

  10. 21 CFR 880.5045 - Medical recirculating air cleaner.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical recirculating air cleaner. 880.5045... Therapeutic Devices § 880.5045 Medical recirculating air cleaner. (a) Identification. A medical recirculating air cleaner is a device used to remove particles from the air for medical purposes. The device...

  11. 21 CFR 880.5045 - Medical recirculating air cleaner.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical recirculating air cleaner. 880.5045... Therapeutic Devices § 880.5045 Medical recirculating air cleaner. (a) Identification. A medical recirculating air cleaner is a device used to remove particles from the air for medical purposes. The device...

  12. 21 CFR 880.5045 - Medical recirculating air cleaner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical recirculating air cleaner. 880.5045... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5045 Medical recirculating air cleaner. (a) Identification. A medical recirculating...

  13. 21 CFR 880.5045 - Medical recirculating air cleaner.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical recirculating air cleaner. 880.5045... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5045 Medical recirculating air cleaner. (a) Identification. A medical recirculating...

  14. Pulsed-focusing recirculating linacs for muon acceleration

    SciTech Connect

    Johnson, Rolland

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

  15. Built to disappear.

    PubMed

    Bauer, Siegfried; Kaltenbrunner, Martin

    2014-06-24

    Microelectronics dominates the technological and commercial landscape of today's electronics industry; ultrahigh density integrated circuits on rigid silicon provide the computing power for smart appliances that help us organize our daily lives. Integrated circuits function flawlessly for decades, yet we like to replace smart phones and tablet computers every year. Disposable electronics, built to disappear in a controlled fashion after the intended lifespan, may be one of the potential applications of transient single-crystalline silicon nanomembranes, reported by Hwang et al. in this issue of ACS Nano. We briefly outline the development of this latest branch of electronics research, and we present some prospects for future developments. Electronics is steadily evolving, and 20 years from now we may find it perfectly normal for smart appliances to be embedded everywhere, on textiles, on our skin, and even in our body.

  16. A Sketch of the Taiwan Zebrafish Core Facility.

    PubMed

    You, May-Su; Jiang, Yun-Jin; Yuh, Chiou-Hwa; Wang, Chien-Ming; Tang, Chih-Hao; Chuang, Yung-Jen; Lin, Bo-Hung; Wu, Jen-Leih; Hwang, Sheng-Ping L

    2016-07-01

    In the past three decades, the number of zebrafish laboratories has significantly increased in Taiwan. The Taiwan Zebrafish Core Facility (TZCF), a government-funded core facility, was launched to serve this growing community. The Core Facility was built on two sites, one located at the National Health Research Institutes (NHRI, called Taiwan Zebrafish Core Facility at NHRI or TZeNH) and the other is located at the Academia Sinica (Taiwan Zebrafish Core Facility at AS a.k.a. TZCAS). The total surface area of the TZCF is about 180 m(2) encompassing 2880 fish tanks. Each site has a separate quarantine room and centralized water recirculating systems, monitoring key water parameters. To prevent diseases, three main strategies have been implemented: (1) imported fish must be quarantined; (2) only bleached embryos are introduced into the main facilities; and (3) working practices were implemented to minimize pathogen transfer between stocks and facilities. Currently, there is no health program in place; however, a fourth measure for the health program, specific regular pathogen tests, is being planned. In March 2015, the TZCF at NHRI has been AAALAC accredited. It is our goal to ensure that we provide "disease-free" fish and embryos to the Taiwanese research community.

  17. KENNEDY SPACE CENTER, FLA. - The Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL), is nearing completion. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - The Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL), is nearing completion. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  18. High-power picosecond laser pulse recirculation.

    PubMed

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  19. [Resistance analyses for recirculated membrane bioreactor].

    PubMed

    Yang, Qi; Huang, Xia; Shang, Hai-Tao; Wen, Xiang-Hua; Qian, Yi

    2006-11-01

    The resistance analyses for recirculated membrane bioreactor by the resistance-in-series model and the modified gel-polarization model respectively were extended to the turbulent ultrafiltration system. The experiments are carried out by dye wastewater in a tubular membrane module, it is found that the permeate fluxes are predicted very well by these models for turbinate systems. And the resistance caused by the concentration polarization is studied; the gel layer resistance is the most important of all the resistances.

  20. Numerical computations of swirling recirculating flow

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Mongia, H. C.

    1980-01-01

    Swirling, recirculating, nonreacting flows were computed using a 2D elliptic program consisting of three tasks. The computations in Task 1 and 2 were made using an independent analysis for the two coaxial swirling flows. The Task 2 computations were made using the measured profiles of the mixing region. In Task 3, a modified 2D elliptic program was employed to include the effects of interaction between the inner and outer streams.

  1. High Power Picosecond Laser Pulse Recirculation

    SciTech Connect

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  2. Recirculating gas separator for electric submersible

    SciTech Connect

    Powers, M.L.

    1991-01-01

    This patent describes a gas separator apparatus for a submersible well pump. It comprises: a rotary gas separator means; and recirculating means for recirculating a portion of the liquid discharged from the discharge outlet back to the separating chamber so that a gas-to-liquid ratio in the separator means is substantially lower than a gas-to-liquid ratio of well fluid entering the well fluid inlet wherein the recirculating means. This patent also describes a method of pumping liquid from a well producing well fluids having a relatively high gas-to-liquid ratio. It comprises: centrifugally separating the well fluid into a liquid and a gas with a separator located downhole in the well; directing the separated liquid toward an inlet of a submersible well pump; recycling a portion of the separated liquid to the separator; and providing an effective gas-to-liquid ratio in the separator substantially lower than a gas-to-liquid ratio of the well fluid prior to separation.

  3. Linear microbunching analysis for recirculation machines

    DOE PAGES

    Tsai, C. -Y.; Douglas, D.; Li, R.; ...

    2016-11-28

    Microbunching instability (MBI) has been one of the most challenging issues in designs of magnetic chicanes for short-wavelength free-electron lasers or linear colliders, as well as those of transport lines for recirculating or energy-recovery-linac machines. To quantify MBI for a recirculating machine and for more systematic analyses, we have recently developed a linear Vlasov solver and incorporated relevant collective effects into the code, including the longitudinal space charge, coherent synchrotron radiation, and linac geometric impedances, with extension of the existing formulation to include beam acceleration. In our code, we semianalytically solve the linearized Vlasov equation for microbunching amplification factor formore » an arbitrary linear lattice. In this study we apply our code to beam line lattices of two comparative isochronous recirculation arcs and one arc lattice preceded by a linac section. The resultant microbunching gain functions and spectral responses are presented, with some results compared to particle tracking simulation by elegant (M. Borland, APS Light Source Note No. LS-287, 2002). These results demonstrate clearly the impact of arc lattice design on the microbunching development. Lastly, the underlying physics with inclusion of those collective effects is elucidated and the limitation of the existing formulation is also discussed.« less

  4. Linear microbunching analysis for recirculation machines

    NASA Astrophysics Data System (ADS)

    Tsai, C.-Y.; Douglas, D.; Li, R.; Tennant, C.

    2016-11-01

    Microbunching instability (MBI) has been one of the most challenging issues in designs of magnetic chicanes for short-wavelength free-electron lasers or linear colliders, as well as those of transport lines for recirculating or energy-recovery-linac machines. To quantify MBI for a recirculating machine and for more systematic analyses, we have recently developed a linear Vlasov solver and incorporated relevant collective effects into the code, including the longitudinal space charge, coherent synchrotron radiation, and linac geometric impedances, with extension of the existing formulation to include beam acceleration. In our code, we semianalytically solve the linearized Vlasov equation for microbunching amplification factor for an arbitrary linear lattice. In this study we apply our code to beam line lattices of two comparative isochronous recirculation arcs and one arc lattice preceded by a linac section. The resultant microbunching gain functions and spectral responses are presented, with some results compared to particle tracking simulation by elegant (M. Borland, APS Light Source Note No. LS-287, 2002). These results demonstrate clearly the impact of arc lattice design on the microbunching development. The underlying physics with inclusion of those collective effects is elucidated and the limitation of the existing formulation is also discussed.

  5. Exhaust gas recirculation system for an internal combustion engine

    SciTech Connect

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  6. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    DOEpatents

    Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  7. Passive recirculation in the National Launch System's fuel feedlines

    NASA Technical Reports Server (NTRS)

    Wilson, W. R.; Holt, K. A.

    1993-01-01

    This report contains the passive recirculation tests on the fuel feedline of the National Launch System (NLS). The majority of testing was performed in February 1992, at the National Institute of Standards and Technology in Boulder, CO. The primary objective was to characterize passive recirculation in the NLS fuel feedline. The objective was met by observing the passive recirculation in a one-fifth scale model of the feedline with clear glass sections. The testing was recorded on video tape and with photographs. A description of the testing apparatus and support equipment is included. The experiment indicates that passive recirculation was occurring; higher angles from the horizontal transfer more heat.

  8. In-tank recirculating arsenic treatment system

    DOEpatents

    Brady, Patrick V [Albuquerque, NM; Dwyer, Brian P [Albuquerque, NM; Krumhansl, James L [Albuquerque, NM; Chwirka, Joseph D [Tijeras, NM

    2009-04-07

    A low-cost, water treatment system and method for reducing arsenic contamination in small community water storage tanks. Arsenic is removed by using a submersible pump, sitting at the bottom of the tank, which continuously recirculates (at a low flow rate) arsenic-contaminated water through an attached and enclosed filter bed containing arsenic-sorbing media. The pump and treatment column can be either placed inside the tank (In-Tank) by manually-lowering through an access hole, or attached to the outside of the tank (Out-of-Tank), for easy replacement of the sorption media.

  9. Recirculating 1-K-Pot for Pulse-Tube Cryostats

    NASA Technical Reports Server (NTRS)

    Paine, Christopher T.; Naylor, Bret J.; Prouve, Thomas

    2013-01-01

    A paper describes a 1-K-pot that works with a commercial pulse tube cooler for astrophysics instrumentation testbeds that require temperatures <1.7 K. Pumped liquid helium-4 cryostats were commonly used to achieve this temperature. However, liquid helium-4 cryostats are being replaced with cryostats using pulse tube coolers. The closed-cycle 1K-pot system for the pulse tube cooler requires a heat exchanger on the pulse tube, a flow restriction, pump-out line, and pump system that recirculates helium-4. The heat exchanger precools and liquefies helium- 4 gas at the 2.5 to 3.5 K pulse tube cold head. This closed-cycle 1-K-pot system was designed to work with commercially available laboratory pulse tube coolers. It was built using common laboratory equipment such as stainless steel tubing and a mechanical pump. The system is self-contained and requires only common wall power to operate. The lift of 15 mW at 1.1 K and base temperature of 0.97 K are provided continuously. The system can be scaled to higher heat lifts of .30 to 50 mW if desired. Ground-based telescopes could use this innovation to improve the efficiency of existing cryo

  10. Design of a computerized, temperature-controlled, recirculating aquaria system

    USGS Publications Warehouse

    Widmer, A.M.; Carveth, C.J.; Keffler, J.W.; Bonar, Scott A.

    2006-01-01

    We built a recirculating aquaria system with computerized temperature control to maintain static temperatures, increase temperatures 1 ??C/day, and maintain diel temperature fluctuations up to 10 ??C. A LabVIEW program compared the temperature recorded by thermocouples in fish tanks to a desired set temperature and then calculated the amount of hot or cold water to add to tanks to reach or maintain the desired temperature. Intellifaucet?? three-way mixing valves controlled temperature of the input water and ensured that all fish tanks had the same turnover rate. The system was analyzed over a period of 50 days and was fully functional for 96% of that time. Six different temperature treatments were run simultaneously in 18, 72 L fish tanks and temperatures stayed within 0.5 ??C of set temperature. We used the system to determine the upper temperature tolerance of fishes, but it could be used in aquaculture, ecological studies, or other aquatic work where temperature control is required. ?? 2005 Elsevier B.V. All rights reserved.

  11. High speed exhaust gas recirculation valve

    SciTech Connect

    Fensom, Rod; Kidder, David J.

    2005-01-18

    In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve that can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled. It is desirable to have an EGR valve with fast-acting capabilities, and it is also desirable to have the EGR valve take up as little space as possible. An exhaust gas recirculation valve is provided that includes an exhaust passage tube, a valve element pivotally mounted within the exhaust passage tube, a linear actuator; and a gear train. The gear train includes a rack gear operatively connected to the linear actuator, and at least one rotatable gear meshing with the rack gear and operatively connected to the valve element to cause rotation of the valve element upon actuation of the linear actuator. The apparatus provides a highly compact package having a high-speed valve actuation capability.

  12. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  13. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  14. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  15. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  16. 40 CFR 1065.127 - Exhaust gas recirculation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  17. Energy savings from air recirculation in peanut curing

    SciTech Connect

    Cook, D.F.; Cundiff, J.S.; Vaughan, D.H.

    1982-12-01

    A thin-layer peanut drying simulation model was adapted to incorporate air recirculation. Laboratory crop dryers were designed and constructed to conduct experiments to verify the model. Five batches of peanuts were dried using different recirculation strategies. The model successfully predicted the results.

  18. Energy conservation by partial recirculation of peanut drying air

    SciTech Connect

    Young, J.H.

    1983-06-01

    Conventional, recirculating, and intermittent type peanut dryers were compared in a three-year study. Comparisons indicate that partial recirculation of peanut drying air may reduce energy consumption per unit of water removed by approximately 25% while also reducing required drying time and maintaining high quality.

  19. Effects of spent liquor recirculation in hydrothermal carbonization.

    PubMed

    Kabadayi Catalkopru, Arzu; Kantarli, Ismail Cem; Yanik, Jale

    2017-02-01

    In this study, the effect of the recirculation of spent liquor from hydrothermal carbonization was investigated depending on the biomass type (grape pomace, orange pomace and poultry litter). The yield and fuel properties of hydrochars and spent liquor characteristics were determined for each recirculation step. By recirculation, mass and energy yields of the hydrochar increased, but their combustion characteristics changed: the ignition temperature and combustion reactivity decreased. The organic and inorganic load of liquor was increased with recirculation number, but not as much as would be expected after the first recycle. It was concluded that the load of organic and inorganic species in spent liquor decreased the leaching of some inorganics and diffusion of the degraded soluble fragments from biomass in the subsequent hydrothermal carbonization. Overall, this study showed that spent liquor recirculation makes the overall hydrothermal carbonization process environmentally friendly.

  20. NGL recovery being hiked by natural-gasoline recirculation

    SciTech Connect

    Rivas M, M.; Bracho, J.L.; Murray, J.E.

    1997-07-07

    Construction will be completed later this year at two compression plants operated by Lagoven, S.A., to install natural-gasoline recirculation to improve NGL recovery. The project is the result of a study of condensate-stream recirculation and absorber operations at the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3), offshore Lake Maracaibo in western Venezuela. The PCTJ-2 and PCTJ-3 gas compression plants have two systems: gas compression and NGL extraction. Previous analysis of the NGL extraction and fractionation processes of Lagoven determined that there are two practical and attractive alternatives for the recirculation of the condensate streams in PCTJ-2 and 3: recirculation of natural gasoline from the Ule LPG plant; recirculation of a conditioned condensate from the de-ethanizer tower of each plant. Both alternatives are discussed. Also described are fractionation capacity, and modifications for adding absorption and fractionation.

  1. AP1000 Features Prevent Potential Containment Recirculation Screen Plugging

    SciTech Connect

    Andreychek, Timothy; Anderson, Richard; Schulz, Terry

    2004-07-01

    This paper presents the results of plant design development and evaluations that demonstrate that the AP1000 plant is not subject to potential containment recirculation screen plugging following a loss-of-coolant-accident (LOCA). Following a LOCA in a pressurized water reactor, it is necessary to recirculate water from the containment back into the reactor to maintain long term core cooling. The AP1000 utilizes passive safety systems to provide containment recirculation for long term core cooling following a LOCA. The AP1000 also has non-safety pumps which provide a backup means of providing recirculation. Screens are provided around the recirculation pipes to prevent debris from blocking recirculation flow and core cooling passages. Debris may be generated by the LOCA blowdown from insulation and coatings used inside containment. Even with effective cleanliness programs, there may be some resident debris such as dust and dirt. The potential for plugging the recirculation screens is a current PWR licensing issue. The AP1000 design provides inherent advantages with respect to the potential plugging of containment recirculation screens. These characteristics include prevention of fibrous debris generation, improved debris settling and improved recirculation screen design. Debris settling analysis demonstrates that failure of coatings does not result in debris being transported to the screens before it settles to the floor. Additional analysis also shows that the plant can tolerate conservative amounts of resident debris being transported to the screens. The AP1000 significantly reduces the probability of plugging the containment recirculation screens and significantly reduces inspection and maintenance of coatings used inside containment. (authors)

  2. Design of a High-Reynolds Number Recirculating Water Tunnel

    NASA Astrophysics Data System (ADS)

    Daniel, Libin; Elbing, Brian

    2014-11-01

    An experimental fluid mechanics laboratory focused on turbulent boundary layers, drag reduction techniques, multiphase flows and fluid-structure interactions has recently been established at Oklahoma State University. This laboratory has three primary components; (1) a recirculating water tunnel, (2) a multiphase pipe flow loop, and (3) a multi-scale flow visualization system. The design of the water tunnel is the focus of this talk. The criteria used for the water tunnel design was that it had to produce a momentum-thickness based Reynolds number in excess of 104, negligible flow acceleration due to boundary layer growth, maximize optical access for use of the flow visualization system, and minimize inlet flow non-uniformity. This Reynolds number was targeted to bridge the gap between typical university/commercial water tunnels (103) and the world's largest water tunnel facilities (105) . These objectives were achieved with a 152 mm (6-inch) square test section that is 1 m long and has a maximum flow speed of 10 m/s. The flow non-uniformity was mitigated with the use of a tandem honeycomb configuration, a settling chamber and an 8.5:1 contraction. The design process that produced this final design will be presented along with its current status.

  3. Recirculating Molten Metal Supply System And Method

    DOEpatents

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-07-01

    The melter furnace includes a heating chamber (16), a pump chamber (18), a degassing chamber (20), and a filter chamber (22). The pump chamber (18) is located adjacent the heating chamber (16) and houses a molten metal pump (30). The degassing chamber (20) is located adjacent and in fluid communication with the pump chamber (18), and houses a degassing mechanism (36). The filter chamber (22) is located adjacent and in fluid communication with the degassing chamber (20). The filter chamber (22) includes a molten metal filter (38). The melter furnace (12) is used to supply molten metal to an externally located holder furnace (14), which then recirculates molten metal back to the melter furnace (12).

  4. Nutrient Management in Recirculating Hydroponic Culture

    NASA Technical Reports Server (NTRS)

    Bugbee, Bruce

    2004-01-01

    There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

  5. Industrial Energy Conservation, Forced Internal Recirculation Burner

    SciTech Connect

    Joseph Rabovitser

    2003-06-19

    The overall objective of this research project is to develop and evaluate an industrial low NOx burner for existing and new gas-fired combustion systems for intermediate temperature (1400 degree to 2000 degree F) industrial heating devices such as watertube boilers and process fluid heaters. A multi-phase effort is being pursued with decision points to determine advisability of continuance. The current contract over Phases II and III of this work. The objectives of each phase are as follows. Phase II - to design, fabricate, and evaluate prototype burners based on the Forced Internal Recirculation (FIR) concept. Phase III - to evaluate the performance of an FIR burner under actual operating conditions in a full-scale field test and establish the performance necessary for subsequent commercialization

  6. Nutrient Management in Recirculating Hydroponic Culture

    NASA Technical Reports Server (NTRS)

    Bugbee, Bruce

    2004-01-01

    There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

  7. Recirculation bubbler for glass melter apparatus

    DOEpatents

    Guerrero, Hector; Bickford, Dennis

    2007-06-05

    A gas bubbler device provides enhanced recirculation of molten glass within a glass melter apparatus. The bubbler device includes a tube member disposed within a pool of molten glass contained in the melter. The tube member includes a lower opening through which the molten glass enters and upper slots disposed close to (above or below) the upper surface of the pool of molten glass and from which the glass exits. A gas (air) line is disposed within the tube member and extends longitudinally thereof. A gas bubble distribution device, which is located adjacent to the lower end of the tube member and is connected to the lower end of the gas line, releases gas through openings therein so as to produce gas bubbles of a desired size in the molten glass and in a distributed pattern across the tube member.

  8. Our Built and Natural Environments

    EPA Pesticide Factsheets

    Our Built and Natural Environments summarizes research that shows how development patterns affect the environment and human health, and how certain development patterns can reduce the environmental and human health impacts of development.

  9. Recirculating planar magnetrons: simulations and experiment

    SciTech Connect

    Franzi, Matthew; Gilgenbach, Ronald; French, David; Lau, Y.Y.; Simon, David; Hoff, Brad; Luginsland, John W.

    2011-07-01

    The Recirculating Planar Magnetron (RPM) is a novel crossed-field device whose geometry is expected to reduce thermal load, enhance current yield as well as ease the geometric limitations in scaling to high RF frequencies as compared to the conventional cylindrical magnetrons. The RPM has two different adaptations: A. Axial B field and radial E field; B. Radial B field and axial E field. The preliminary configuration (A) to be used in experiments at the University of Michigan consists of two parallel planar sections which join on either end by cylindrical regions to form a concentric extruded ellipse. Similar to conventional magnetrons, a voltage across the AK gap in conjunction with an axial magnetic field provides the electrons with an ExB drift. The device is named RPM because the drifting electrons recirculate from one planar region to the other. The drifting electrons interact with the resonantly tuned slow wave structure on the anode causing spoke formation. These electron spokes drive a RF electric field in the cavities from which RF power may be extracted to Waveguides. The RPM may be designed in either a conventional configuration with the anode on the outside, for simplified extraction, or as an inverted magnetron with the anode at the inner conductor, for fast start-up. Currently, experiments at the Pulsed Power and Microwave Laboratory at the University of Michigan are in the setup and design phase. A conventional RPM with planar cavities is to be installed on the Michigan Electron Long Beam Accelerator (MELBA) and is anticipated to operate at -200kV, 0.2T with a beam current of 1-10 kA at 1GHz. The conventional RPM consists of 12 identical planar cavities, 6 on each planar side, with simulated quality factor of 20.

  10. Study of atmospheric stagnation, recirculation and ventilation potential at Narora Atomic Power Station NPP site.

    PubMed

    Kumar, Deepak; Kumar, Avinash; Kumar, Vimal; Kumar, Jaivender; Ravi, P M

    2013-04-01

    The atmosphere is an important pathway to be considered in assessment of the environmental impact of radioactivity releases from nuclear facilities. The estimation of concentration of released effluents in air and possible ground contamination needs an understanding of relevant atmospheric dispersion. This paper describes the meteorological characteristics of Narora Atomic Power Station (NAPS) Nuclear Power Project site by using the integral parameters developed by Allwine and Whiteman (Atmospheric Environment 28(4):713-721, 1994). Meteorological data measured during the period 2006-2010 were analysed. The integral quantities related to the occurrence of stagnation, recirculation and ventilation characteristics were studied for the NAPS site to assess the dilution potential of the atmosphere. Wind run and recirculation factors were calculated for a 24-h transport time using 5 years of hourly surface measurements of wind speed and direction. The occurrence of stagnation, recirculation and ventilation characteristics during 2006-2010 at the NAPS site is observed to be 33.8, 19.5 and 34.7 % of the time, respectively. The presence of strong winds with predominant wind direction NW and WNW during winter and summer seasons leads to higher ventilation (48.1 and 44.3 %) and recirculation (32.6 % of the summer season). The presence of more dispersed light winds during pre-winter season with predominant wind directions W and WNW results in more stagnation (59.7 % of the pre-winter season). Thus, this study will serve as an essential meteorological tool to understand the transport mechanism of atmospheric radioactive effluent release from any nuclear industry during the pre-operational as well as operational phase.

  11. Progress toward a prototype recirculating ion induction accelerator

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Cable, M.D.

    1996-06-01

    The U.S. Inertial Fusion Energy (IFE) Program is developing the physics and technology of ion induction accelerators, with the goal of electric power production by means of heavy ion beam-driven inertial fusion (commonly called heavy ion fusion, or HIF). Such accelerators are the principal candidates for inertial fusion power production applications, because they are expected to enjoy high efficiency, inherently high pulse repetition frequency (power plants are expected to inject and burn several fusion targets per second), and high reliability. In addition (and in contrast with laser beams, which are focused with optical lenses) heavy-ion beams will be focused onto the target by magnetic fields, which cannot be damaged by target explosions. Laser beams are used in present-day and planned near-term facilities (such as LLNUs Nova and the National Ignition Facility, which is being designed) because they can focus beams onto very small, intensely illuminated spots for scaled experiments and because the laser technology is already available. An induction accelerator works by passing the beam through a series of accelerating modules, each of which applies an electromotive force to the beam as it goes by; effectively, the beam acts as the secondary winding of a series of efficient one-turn transformers. The authors present plans for and progress toward the development of a small (4.5-m-diam) prototype recirculator, which will accelerate singly charged potassium ions through 15 laps, increasing the ion energy from 80 to 320 keV and the beam current from 2 to 8 mA. Beam confinement and bending are effected with permanent-magnet quadrupoles and electric dipoles, respectively. The design is based on scaling laws and on extensive particle and fluid simulations of the behavior of the space charge-dominated beam.

  12. Recirculating induction accelerators for inertial fusion: Prospects and status

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Cable, M.D.

    1995-11-29

    The U.S. is developing the physics and technology of induction accelerators for heavy-ion beam-driven inertial fusion. The recirculating induction accelerator repeatedly passes beams through the same set of accelerating and focusing elements, thereby reducing both the length and gradient of the accelerator structure. This promises an attractive driver cost, if the technical challenges associated with recirculation can be met. Point designs for recirculator drivers were developed in a multi-year study by LLNL, LBNL, and FM Technologies, and that work is briefly reviewed here. To validate major elements of the recirculator concept, we are developing a small (4.5-m diameter) prototype recirculator which will accelerate a space-charge-dominated beam of K{sup +} ions through 15 laps, from 80 to 320 keV and from 2 to 8 mA. Transverse beam confinement is effected via permanent-magnet quadrupoles; bending is via electric dipoles. This {open_quotes}Small Recirculator{close_quotes} is being developed through a sequence of experiments. An injector, matching section, and linear magnetic channel using seven half-lattice periods of permanent-magnet quadrupole lenses are operational. A prototype recirculator half-lattice period is being fabricated. This paper outlines the research program, and presents initial experimental results.

  13. Recirculating induction accelerators for inertial fusion: Prospects and status

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Cable, M.D.

    1995-09-03

    The US is developing the physics and technology of induction accelerators for heavy-ion beam-driven inertial fusion. The recirculating induction accelerator repeatedly passes beams through the same set of accelerating and focusing elements, thereby reducing both the length and gradient of the accelerator structure. This promises an attractive driver cost, if the technical challenges associated with recirculation can be met. Point designs for recirculator drivers were developed in a multi-year study by LLNL, LBNL, and FM Technologies, and that work is briefly reviewed here. To validate major elements of the recirculator concept, we are developing a small (4-5-m diameter) prototype recirculator which will accelerate a space-charge-dominated beam of K{sup +} ions through 15 laps, from 80 to 320 keV and from 2 to 8 mA. Transverse beam confinement is effected via permanent-magnet quadrupoles; bending is via electric dipoles. This ``Small Recirculator`` is being developed in a build-and-test sequence of experiments. An injector, matching section, and linear magnetic channel using seven half-lattice periods of permanent-magnet quadrupole lenses are operational. A prototype recirculator half-lattice period is being fabricated. This paper outlines the research program, and presents initial experimental results.

  14. Exhaust gas recirculation method for internal combustion engines

    SciTech Connect

    Kawanabe, T.; Kimura, K.; Asakura, M.; Shiina, T.

    1988-07-19

    This patent describes a method of controlling exhaust gas recirculation in an internal combustion engine having an exhaust passage, an intake passage, an exhaust gas recirculating passage communicating the exhaust passage with the intake passage, and exhaust gas recirculating valve; and a transmission having a shift lever. The valve opening of the exhaust gas recirculating valve is controlled in response to operating conditions of the engine so as to regulate the amount of exhaust gas recirculation to values appropriate to the operating conditions of the engine. The method comprising the steps of (1) determining whether or not the engine is in at least one of a predetermined accelerating condition and a predetermined decelerating condition; (2) varying the valve opening of the exhaust gas recirculating valve by a predetermined value when the engine is determined to be in at least one of the predetermined accelerating condition and the predetermined decelerating condition; (3) detecting a position of the shift lever of the transmission; and (4) correcting the predetermined value in accordance with the detected position of the shift lever so as to increase the valve opening of the exhaust gas recirculating valve as the shift lever of the transmission is set to a higher speed position.

  15. Recirculating Beam Breakup Study for the 12 GeV Upgrade at Jefferson Lab

    SciTech Connect

    Ilkyoung Shin, Todd Satogata, Shahid Ahmed, Slawomir Bogacz, Mircea Stirbet, Haipeng Wang, Yan Wang, Byung Yunn, Ryan Bodenstein

    2012-07-01

    Two new high gradient C100 cryomodules with a total of 16 new cavities were installed at the end of the CEBAF south linac during the 2011 summer shutdown as part of the 12-GeV upgrade project at Jefferson Lab. We surveyed the higher order modes (HOMs) of these cavities in the Jefferson Lab cryomodule test facility and CEBAF tunnel. We then studied recirculating beam breakup (BBU) in November 2011 to evaluate CEBAF low energy performance, measure transport optics, and evaluate BBU thresholds due to these HOMs. This paper discusses the experiment setup, cavity measurements, machine setup, optics measurements, and lower bounds on BBU thresholds by new cryomodules.

  16. Nonresonant Recirculating Type II Second-Harmonic Generator

    NASA Astrophysics Data System (ADS)

    Ross, T. Sean; Moore, Gerald T.

    2004-04-01

    We show an experimental proof of concept for a nonresonant recirculation method to increase the conversion efficiency of second-harmonic generation (SHG) with type II phase matching. As much as a factor-of-4 efficiency increase compared with that of single-pass SHG is possible, provided that the recirculation length is within the coherence length of the pump laser. Nonresonant recirculating SHG may be valuable in systems in which intracavity doubling is not practicable, such as high-power cw bulk solid-state or fiber lasers.

  17. Measuring the Built Environment for Physical Activity

    PubMed Central

    Brownson, Ross C.; Hoehner, Christine M.; Day, Kristen; Forsyth, Ann; Sallis, James F.

    2009-01-01

    Physical inactivity is one of the most important public health issues in the U.S. and internationally. Increasingly, links are being identified between various elements of the physical—or built—environment and physical activity. To understand the impact of the built environment on physical activity, the development of high-quality measures is essential. Three categories of built environment data are being used: (1) perceived measures obtained by telephone interview or self-administered questionnaires; (2) observational measures obtained using systematic observational methods (audits); and (3) archival data sets that are often layered and analyzed with GIS. This review provides a critical assessment of these three types of built-environment measures relevant to the study of physical activity. Among perceived measures, 19 questionnaires were reviewed, ranging in length from 7 to 68 questions. Twenty audit tools were reviewed that cover community environments (i.e., neighborhoods, cities), parks, and trails. For GIS-derived measures, more than 50 studies were reviewed. A large degree of variability was found in the operationalization of common GIS measures, which include population density, land-use mix, access to recreational facilities, and street pattern. This first comprehensive examination of built-environment measures demonstrates considerable progress over the past decade, showing diverse environmental variables available that use multiple modes of assessment. Most can be considered first-generation measures, so further development is needed. In particular, further research is needed to improve the technical quality of measures, understand the relevance to various population groups, and understand the utility of measures for science and public health. PMID:19285216

  18. Production of market-size North American strain Atlantic salmon Salmo salar in a land-based recirculation aquaculture system using freshwater

    USDA-ARS?s Scientific Manuscript database

    There is interest in culturing Atlantic salmon Salmo salar to market-size in land-based, closed containment systems that use recirculation aquaculture systems (RAS), as this technology often enables facilities to locate near major markets, obtain permits, exclude obligate pathogens, and/or reduce en...

  19. Engine with pulse-suppressed dedicated exhaust gas recirculation

    DOEpatents

    Keating, Edward J.; Baker, Rodney E.

    2016-06-07

    An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.

  20. Pulsed Magnet Arc Designs for Recirculating Linac Muon Accelerators

    SciTech Connect

    K.B. Beard, R.P. Johnson, S.A. Bogacz, G.M. Wang

    2009-05-01

    Recirculating linear accelerators (RLAs) using both pulsed quadrupoles and pulsed dipoles can be used to quickly accelerate muons in the 3 – 2000 GeV range. Estimates on the requirements for the pulsed quadrupoles and dipoles are presented.

  1. Eddy-driven recirculation of Atlantic Water in Fram Strait

    NASA Astrophysics Data System (ADS)

    Hattermann, Tore; Isachsen, Pâl. Erik; Appen, Wilken-Jon; Albretsen, Jon; Sundfjord, Arild

    2016-04-01

    Eddy-resolving regional ocean model results in conjunction with synthetic float trajectories and observations provide new insights into the recirculation of the Atlantic Water (AW) in Fram Strait that significantly impacts the redistribution of oceanic heat between the Nordic Seas and the Arctic Ocean. The simulations confirm the existence of a cyclonic gyre around the Molloy Hole near 80°N, suggesting that most of the AW within the West Spitsbergen Current recirculates there, while colder AW recirculates in a westward mean flow south of 79°N that primarily relates to the eastern rim of the Greenland Sea Gyre. The fraction of waters recirculating in the northern branch roughly doubles during winter, coinciding with a seasonal increase of eddy activity along the Yermak Plateau slope that also facilitates subduction of AW beneath the ice edge in this area.

  2. Future of recirculating systems in the US aquaculture industry

    SciTech Connect

    Malone, R.F.

    1994-08-01

    Recirculating systems consist of a culture unit, a recirculating pump, and a treatment block which facilitate extended re-use of water in the rearing of aquatic animals. As water re-use is extended from a few hours to months or even years, the complexity of the treatment block increases. Classified as either `open` with greater than 10 percent water replacement per day or `closed` with less than 10 percent daily replacement, most recirculating systems include aerators, clarifiers, and biofilters as key core elements. The aquaculture industry is increasingly facing a variety of socio-economic issues which will dramatically influence its future development. These problems range from increased competition for water rights through price depression and foreign imports to predation by protected migratory birds. As water-use, environmental, and conservation conflicts grow, the cost differences between the flow-through and closed production technologies will narrow, increasing the industry`s use of recirculating systems.

  3. A closed recirculated sea-water system

    USGS Publications Warehouse

    1967-01-01

    Study of a virus disease in the chinook salmon (Oncorhynchus tshawytscha) necessitated the use of a marine environment to study the long range effects of the disease and to complete the life cycle of its etiologic agent. A closed recirculated sea-water system was designed for use under experimental laboratory conditions so that controlled studies of the disease could be made. As others may wish to do marine environment studies in the laboratory, the design and operation of our system are presented. Other systems currently in use have been described by Chin (1959), DeWitt and Salo (1960), McCrimmon and Berst (1966), and the authors of collected papers edited by Clark and Clark (1964). Preparatory to the design and construction of the system in use in this laboratory, visits were made to marine systems in use at the University of Washington's College of Fisheries, Seattle, -washington, and Friday Harbor Laboratory, San Juan Island, Washington; the Washington State Department of Fisheries' Point whitney Shellfish Laboratory, Brinnon, Washington; Humboldt State College, Arcata, California; and the Steinhart Aquarium of the California Academy of Science, San Francisco, California.

  4. Schools Built with Fallout Shelter.

    ERIC Educational Resources Information Center

    Office of Civil Defense (DOD), Washington, DC.

    Fallout protection can be built into a school building with little or no additional cost, using areas that are in continual use in the normal functioning of the building. A general discussion of the principles of shelter design is given along with photographs, descriptions, drawings, and cost analysis for a number of recently constructed schools…

  5. LONGITUDINAL REFERENCE PARTICLE MOTION IN NEARLY ISOCHRONOUS FFAG RECIRCULATING ACCELERATORS.

    SciTech Connect

    BERG,J.S.

    2001-07-01

    A Fixed Field Alternating Gradient (FFAG) arc can be used to reduce the cost of a recirculating accelerator. Path length variation with energy in such an arc can limit its usefulness, however, due to phase offset at the linac. This paper examines the dynamics of the reference particle in an FFAG recirculating accelerator, and describes the limitations on the design because of path length variation with energy.

  6. The Pebble Recirculation Experiment (PREX) for the AHTR

    SciTech Connect

    Bardet, P.; An, J.Y.; Franklin, J.T.; Huang, D.; Lee, K.; Mai, A.; Toulouse, M.; Peterson, P.F.

    2007-07-01

    Conceptual design studies for the liquid-salt cooled Advanced High Temperature Reactor (AHTR) have identified three candidate TRISO fuel geometries: prismatic, pebble, and stringer fuels. This paper presents experimental results from the integral Pebble Recirculation Experiment (PREX) that verifies the viability of pebble recirculation in a Pebble Bed AHTR (PB-AHTR). The experiments conducted include injection and extraction of buoyant pebbles, measurements of packing density and pressure losses, and observations of pebble landing dynamics and bed formation. (authors)

  7. Demonstration of Spray Booth Recirculation and Partitioning - Phase II

    DTIC Science & Technology

    1996-01-01

    electrostatic paint spray enclosures, such as the high volume, low pressure ( HVLP ) systems employed at Barstow MCLB, a minimum linear velocity of 100 fpm must be...SUBTITLE 5. FUNDING NUMBERS Demonstration of Spray Booth Recirculation and Partitioning - Phase II N/A 6. AUTHOR(S) D. Proffitt, R.K. Clayton, & J...ANSI Std. Z39-18 298-102 * , 85-1996 Demonstration of Spray Booth Recirculation and Partitioning - Phase II David Proffitt and Russell K. Clayton

  8. XLR 500i: recirculating ring ArF light source for immersion lithography

    NASA Astrophysics Data System (ADS)

    Brown, D. J. W.; O'Keeffe, P.; Fleurov, V. B.; Rokitski, R.; Bergstedt, R.; Fomenkov, I. V.; O'Brien, K.; Farrar, N. R.; Partlo, W. N.

    2007-03-01

    As Argon Fluoride (ArF) lithography moves into high volume production, ArF light sources need to meet performance requirements beyond the traditional drivers of power and bandwidth. The first key requirement is a continuous decrease in Cost of Ownership (CoO) where the industry requirement is for reduction in ArF CoO in line with the historical cost reduction demonstrated for Krypton Fluoride (KrF) light sources. A second requirement is improved light source performance stability. As CD control requirements shrink, following the ITRS roadmap, all process parameters which affect CD variation need tighter control. In the case of the light source, these include improved control of bandwidth, pulse energy stability and wavelength. In particular, CD sensitivity to exposure dose has become a serious challenge for device processing and improvements to laser pulse energy stability can contribute to significantly better dose control. To meet these performance challenges Cymer has designed a new dual chamber laser architecture. The Recirculating Ring design requires 10X less energy from the Master Oscillator (MO). This new configuration enables the MO chamber lifetime to reach that of the power amplifier chamber at around 30Bp. In addition, other optical modules in the system such as the line narrowing module experience lower light intensity, ensuring even longer optics lifetime. Furthermore, the Recirculating Ring configuration operates in much stronger saturation. MO energy instabilities are reduced by a factor of 9X when passed through the Ring. The output energy stability exhibits the characteristics of a fully saturated amplifier and pulse energy stability improvement of 1.5X is realized. This performance enables higher throughput scanner operation with enhanced dose control. The Recirculating Ring technology will be introduced on the XLR 500i, Cymer's fifth-generation dual chamber-based light source built on the production-proven XLA platform. This paper will describe

  9. KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the U.S. Node 2, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station.

    NASA Image and Video Library

    2003-06-19

    KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the U.S. Node 2, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station.

  10. Built Environment Wind Turbine Roadmap

    SciTech Connect

    Smith, J.; Forsyth, T.; Sinclair, K.; Oteri, F.

    2012-11-01

    The market currently encourages BWT deployment before the technology is ready for full-scale commercialization. To address this issue, industry stakeholders convened a Rooftop and Built-Environment Wind Turbine Workshop on August 11 - 12, 2010, at the National Wind Technology Center, located at the U.S. Department of Energy’s National Renewable Energy Laboratory in Boulder, Colorado. This report summarizes the workshop.

  11. Case study of controlled recirculation at a Wyoming trona mine

    PubMed Central

    Pritchard, C.; Scott, D.; Frey, G.

    2015-01-01

    Controlled recirculation has been used in the metal/nonmetal mining industry for energy savings when heating and cooling air, in undersea mining and for increasing airflow to mining areas. For safe and effective use of controlled district recirculation, adequate airflow to dilute contaminants must exist prior to implementation, ventilation circuit parameters must be accurately quantified, ventilation network modeling must be up to date, emergency planning scenarios must be performed and effective monitoring and control systems must be installed and used. Safety and health issues that must be considered and may be improved through the use of controlled district recirculation include blasting fumes, dust, diesel emissions, radon and contaminants from mine fires. Controlled recirculation methods are expected to become more widely used as mines reach greater working depths, requiring that these health and safety issues be well understood. The U.S. National Institute for Occupational Safety and Health (NIOSH) conducted two controlled recirculation tests over three days at a Wyoming trona mine, utilizing an inline booster fan to improve airflow to a remote and difficult-to-ventilate development section. Test results were used to determine the effect that recirculation had on air qualities and quantities measured in that section and in other adjacent areas. Pre-test conditions, including ventilation quantities and pressures, were modeled using VnetPC. During each test, ventilation quantities and pressures were measured, as well as levels of total dust. Sulfur hexafluoride (SF6) tracer gas was used to simulate a mine contaminant to monitor recirculation wave cycles. Results showed good correlation between the model results and measured values for airflows, pressure differentials, tracer gas arrival times, mine gasses and dust levels. PMID:26251567

  12. Investigation of induced recirculation during planned ventilation system maintenance

    PubMed Central

    Pritchard, C.J.; Scott, D.F.; Noll, J.D.; Voss, B.; Leonis, D.

    2015-01-01

    The Office of Mine Safety and Health Research (OMSHR) investigated ways to increase mine airflow to underground metal/nonmetal (M/NM) mine working areas to improve miners’ health and safety. One of those areas is controlled recirculation. Because the quantity of mine air often cannot be increased, reusing part of the ventilating air can be an effective alternative, if implemented properly, until the capacity of the present system is improved. The additional airflow can be used to provide effective dilution of contaminants and higher flow velocities in the underground mine environment. Most applications of controlled recirculation involve taking a portion of the return air and passing it back into the intake to increase the air volume delivered to the desired work areas. OMSHR investigated a Nevada gold mine where shaft rehabilitation was in progress and one of the two main fans was shut down to allow reduced air velocity for safe shaft work. Underground booster fan operating pressures were kept constant to maintain airflow to work areas, inducing controlled recirculation in one work zone. Investigation into system behavior and the effects of recirculation on the working area during times of reduced primary ventilation system airflow would provide additional information on implementation of controlled recirculation into the system and how these events affect M/NM ventilation systems. The National Institute for Occupational Safety and Health monitored the ventilation district when both main fans were operating and another scenario with one of the units turned off for maintenance. Airflow and contaminants were measured to determine the exposure effects of induced recirculation on miner health. Surveys showed that 19% controlled recirculation created no change in the overall district airflow distribution and a small reduction in district fresh air intake. Total dust levels increased only modestly and respirable dust levels were also low. Diesel particulate matter

  13. Cannula Design and Recirculation During Venovenous Extracorporeal Membrane Oxygenation

    PubMed Central

    Palmér, Oscar; Palmér, Kenneth; Hultman, Jan

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) is used as a lifesaving rescue treatment in refractory respiratory or cardiac failure. During venovenous (VV) ECMO, the presence of recirculation is known, but quantification and actions to minimize recirculation after measurement are to date not routinely practiced. In the current study, we investigated the effect of draining cannula design on recirculation fraction (Rf) during VV ECMO; conventional mesh cannula was compared with a multistage cannula. The effect of adjusting cannula position was also studied. Recirculation was measured with ultrasound dilution technique at different ECMO flows and after cannula repositioning. All patients who were admitted to our unit between October 2014 and July 2015 catheterized by the atrio-femoral single lumen method were included. A total of 108 measurements were conducted in 14 patients. The multistage cannula showed significantly less recirculation (19.0 ± 12.2%) compared with the conventional design (38.0 ± 13.7). Pooled data in cases improved from adjustment showing reduced Rf by 7%. In conclusion, the choice of cannula matters, as does adjustment of the draining cannula position during atrio-femoral VV ECMO. By utilizing the ultrasound dilution technique to measure Rf before and after repositioning, effective ECMO flow can be improved for a more effective ECMO treatment. PMID:27660904

  14. KENNEDY SPACE CENTER, FLA. - Employees check out the new chamber facilities of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). From left are Ray Wheeler, with NASA; Debbie Wells and Larry Burns, with Dynamac; A.O. Rule, president of Environmental Growth Chambers, Inc. (ECG); Neil Yorio, with Dynamac; and John Wiezchowski, with ECG. The SLSL is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - Employees check out the new chamber facilities of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). From left are Ray Wheeler, with NASA; Debbie Wells and Larry Burns, with Dynamac; A.O. Rule, president of Environmental Growth Chambers, Inc. (ECG); Neil Yorio, with Dynamac; and John Wiezchowski, with ECG. The SLSL is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  15. Acceleration schedules for a recirculating heavy-ion accelerator

    SciTech Connect

    Sharp, W.M.; Grote, D.P.

    2002-05-01

    Recent advances in solid-state switches have made it feasible to design programmable, high-repetition-rate pulsers for induction accelerators. These switches could lower the cost of recirculating induction accelerators, such as the ''small recirculator'' at Lawrence Livermore National Laboratory (LLNL), by substantially reducing the number of induction modules. Numerical work is reported here to determine what effects the use of fewer pulsers at higher voltage would have on the beam quality of the LLNL small recirculator. Lattices with different numbers of pulsers are examined using the fluid/envelope code CIRCE, and several schedules for acceleration and compression are compared for each configuration. For selected schedules, the phase-space dynamics is also studied using the particle-in-cell code WARP3d.

  16. Hydrothermal carbonization: process water characterization and effects of water recirculation.

    PubMed

    Stemann, Jan; Putschew, Anke; Ziegler, Felix

    2013-09-01

    Poplar wood chips were treated hydrothermally and the increase of process efficiency by water recirculation was examined. About 15% of the carbon in the biomass was dissolved in the liquid phase when biomass was treated in de-ionized water at 220 °C for 4 h. The dissolved organic matter contained oxygen and was partly aerobically biodegradable. About 30-50% of the total organic carbon originated from organic acids. A polar and aromatic fraction was extracted and a major portion of the organic load was of higher molecular weight. By process water recirculation organic acids in the liquid phase concentrated and catalyzed dehydration reactions. As a consequence, functional groups in hydrothermally synthesized coal declined and dewaterability was enhanced. Recirculated reactive substances polymerized and formed additional solid substance. As a result, carbon and energetic yields of the produced coal rose to 84% and 82%, respectively.

  17. Boosting devices with integral features for recirculating exhaust gas

    DOEpatents

    Wu, Ko-Jen

    2015-12-22

    According to one embodiment of the invention, a turbine housing includes a turbine inlet in fluid communication with a turbine volute configured to house a turbine wheel, the turbine inlet configured to direct an exhaust gas flow from an engine to the turbine wheel. The turbine housing also includes a turbine outlet in fluid communication with the turbine volute, the turbine outlet configured to direct the exhaust gas flow to an exhaust gas conduit and a first exhaust gas recirculation supply port located on and in fluid communication with the turbine outlet, the first exhaust gas recirculation supply port being configured to direct a portion of the exhaust gas flow to an exhaust gas recirculation supply conduit.

  18. Envelope model of a heavy-ion recirculator

    SciTech Connect

    Sharp, W.M.; Barnard, J.J.; Yu, S.S.

    1990-12-01

    A simple transport code has been developed to model the beam in a heavy-ion recirculating accelerator. The novel feature of the model is the treatment of the beam charge density as a Lagrangian fluid in the axial direction. In addition, the envelope and centroid equations include terms that account for the transverse self-force, image forces, and bend fields in the paraxial limit. The use of compressible'' beam slices makes the code suitable for designing the acceleration and compression schedules. The code has been used primarily to design the lattice of the LLNL recirculator, and preliminary magnet configurations for that machine are presented here. 3 refs., 2 figs.

  19. Phase Transfer Measurements at the Jefferson Lab Recirculated Linacs

    SciTech Connect

    Geoffrey Krafft; J. Hovater; B. Bowling; M. Crofford

    2005-06-01

    Bunch length or longitudinal phase space distribution measurements are often used to evaluate if the electron beam meets RF criteria for a recirculated linac. Unfortunately, in many instances when the beam fails to meet the needed criteria, such measurements provide little guidance as to which machine element is problematic. All of the Jefferson Lab recirculated linacs have employed longitudinal phase transfer measurement systems to provide both useful information on the initial understanding of the dynamics of the longitudinal phase space in these accelerators, and much more useful diagnosis of out-of-specification performance of machine RF elements. These systems can provide precision transfer function measurements in time scales convenient for machine operations.

  20. A recirculating cooling system for improved topical cardiac hypothermia.

    PubMed

    Rosenfeldt, F L; Fambiatos, A; Pastoriza-Pinol, J; Stirling, G R

    1981-10-01

    A simple system is described that recirculates cooling fluid for topical cardiac hypothermia. This disposable system can produce a flow of 1,500 ml/min at 2 degrees to 4 degrees C. The recirculating cooler produced significantly lower myocardial temperatures than a conventional fluid-discard system in 22 patients having coronary operation. This system has been used as part of the technique of hypothermic cardioplegia in more than 600 patients. During various cardiac procedures, septal temperatures were maintained well below 20 degrees C for 60 minutes or more without the need to reinfuse the cardioplegic solution.

  1. Boosting devices with integral features for recirculating exhaust gas

    DOEpatents

    Wu, Ko -Jen

    2015-09-15

    According to one embodiment of the invention, a compressor housing includes a compressor inlet in fluid communication with a compressor volute configured to house a compressor wheel, the compressor inlet configured to provide a first air flow to the compressor wheel and a compressor outlet in fluid communication with the compressor volute, the compressor outlet configured to direct a compressed gas to an intake manifold. The compressor housing further includes an exhaust gas recirculation inlet port in fluid communication with the compressor volute, the exhaust gas recirculation inlet port being configured to combine an exhaust gas flow with the air flow to the compressor wheel.

  2. Built-Environment Report Summary

    SciTech Connect

    Baring-Gould, Ian; Fields, Jason; Preus, Robert; Oteri, Frank

    2016-06-14

    Built-environment wind turbine (BEWT) projects are wind energy projects that are constructed on, in, or near buildings. These projects present an opportunity for distributed, low-carbon generation combined with highly visible statements on sustainability, but the BEWT niche of the wind industry is still developing and is relatively less mature than the utility-scale wind or conventional ground-based distributed wind sectors. The findings presented in this presentation cannot be extended to wind energy deployments in general because of the large difference in application and technology maturity. This presentation summarizes the results of a report investigating the current state of the BEWT industry by reviewing available literature on BEWT projects as well as interviewing project owners on their experiences deploying and operating the technology. The authors generated a series of case studies that outlines the pertinent project details, project outcomes, and lessons learned.

  3. Recirculating gravel filters: high-performance treatment at low cost for two small communities.

    PubMed

    Newton, C; Wilson, J P

    2008-01-01

    Wastewater from small communities often has a greater environmental impact than conventional on-site treatment systems can mitigate, yet the flow rate is too low to achieve economies of scale with municipal treatment processes. As a result, the cost of wastewater treatment is often beyond the financial means of the community, in terms of capital costs and annual operational costs. The recirculating gravel filter (RGF) is an attached-growth treatment process for wastewater from small communities. In the RGF process, pre-settled wastewater is recirculated through a gravel filter bed, while a biofilm on the filter media oxidizes the organic matter and ammonia. Effluent from the RGF process has equivalent or lower concentrations of BOD5, TSS and ammonia nitrogen as effluent from other wastewater treatment processes typically employed in small communities. Two small communities in Washington State, USA, have selected the RGF process for wastewater treatment, due to low operational costs, simplicity of equipment, and high effluent quality. For the two communities, the RGF wastewater treatment facilities were estimated to have somewhat lower construction costs and significantly lower annual operational costs than the alternatives evaluated. Low annual operational expenses are important for wastewater system sustainability in small communities. IWA Publishing 2008.

  4. LUX — A Recirculating Linac-based Ultrafast X-ray Source

    NASA Astrophysics Data System (ADS)

    Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Green, M. A.; Heimann, P.; Leone, S. R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2004-05-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme. We describe the facility major systems and peformance.

  5. A fuel cell balance of plant test facility

    NASA Astrophysics Data System (ADS)

    Dicks, A. L.; Martin, P. A.

    Much attention is focused in the fuel cell community on the development of reliable stack technology, but to successfully exploit fuel cells, they must form part of integrated power generation systems. No universal test facilities exist to evaluate SOFC stacks and comparatively little research has been undertaken concerning the issues of the rest of the system, or balance of plant (BOP). BG, in collaboration with Eniricerche, has therefore recently designed and built a test facility to evaluate different configurations of the BOP equipment for a 1-5 kWe solid oxide fuel cell (SOFC) stack. Within this BOP project, integrated, dynamic models have been developed. These have shown that three characteristic response times exist when the stack load is changed and that three independent control loops are required to manage the almost instantaneous change in power output from an SOFC stack, maintain the fuel utilisation and control the stack temperature. Control strategies and plant simplifications, arising from the dynamic modelling, have also been implemented in the BOP test facility. An SOFC simulator was designed and integrated into the control system of the test rig to behave as a real SOFC stack, allowing the development of control strategies without the need for a real stack. A novel combustor has been specifically designed, built and demonstrated to be capable of burning the low calorific anode exhaust gas from an SOFC using the oxygen depleted cathode stream. High temperature, low cost, shell and tube heat exchangers have been shown to be suitable for SOFC systems. Sealing of high temperature anode recirculation fans has, however, been shown to be a major issue and identified as a key area for further investigation.

  6. In-tank aeration, a necessary compliment of loaded systems in an airlift recirculating aquaculture system

    USDA-ARS?s Scientific Manuscript database

    Water treatment components in recirculating aquaculture systems in generally address solids removal, nitrification, circulation, aeration, and degasification. Airlift pumps in a recirculating aquaculture system can address water circulation, aeration, and degasification. Recent data indicates oxygen...

  7. Reduction in performance due to recirculation in mechanical-draft cooling towers

    SciTech Connect

    Kroger, D.G. )

    1989-01-01

    The influence of recirculating warm plume air on the performance of mechanical-draft cooling towers is investigated analytically, numerically and experimentally. It is shown that the amount of recirculation that occurs is a function of the flow and the thermal and geometric characteristics of the tower. The presence of a wind wall tends to reduce the mount of recirculation. An equation is presented with which the performance effectiveness due to recirculation can be evaluated approximately for a mechanical-draft cooling tower.

  8. The effect of flow recirculation on abdominal aortic aneurysm

    NASA Astrophysics Data System (ADS)

    Taib, Ishkrizat; Amirnordin, Shahrin Hisham; Madon, Rais Hanizam; Mustafa, Norrizal; Osman, Kahar

    2012-06-01

    The presences of flow recirculation at the abdominal aortic aneurysm (AAA) region yield the unpredictable failure of aneurismal wall. The failure of the aneurismal wall is closely related to the hemodynamic factor. Hemodynamic factor such as pressure and velocity distribution play a significance role of aneurysm growth and rupture. By using the computational approach, the influence of hemodynamic factor is investigated using computational fluid dynamic (CFD) method on the virtual AAA model. The virtual 3D AAAs model was reconstructed from Spiral Computed Tomography scan (CT-scan). The blood flow is assumed as being transient, laminar and Newtonian within a rigid section of the vessel. The blood flow also driven by an imposed of pressure gradient in the form of physiological waveform. The pulsating blood flow is also considered in this simulation. The results on pressure distribution and velocity profile are analyzed to interpret the behaviour of flow recirculation. The results show the forming of vortices is seen at the aneurysm bulge. This vortices is form at the aneurysm region then destroyed rapidly by flow recirculation. Flow recirculation is point out much higher at distal end of aneurysm closed to iliac bifurcation. This phenomenon is managed to increase the possibility of aneurysm growth and rupture.

  9. Low head oxygenator performance characterization for marine recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    This study evaluated the effect of temperature (20 and 25 ºC), salinity (10, 15, and 20 ppt), and dissolved oxygen levels within low head oxygenator (LHO) outlet water on oxygen transfer efficiency (OTE) of LHOs for a planned marine recirculating aquaculture system (RAS). Test results indicated tha...

  10. An Inexpensive Recirculating Aquaculture System with Multiple Use Capabilities.

    ERIC Educational Resources Information Center

    Scurlock, Gerald Don, Jr.; Cook, S. Bradford; Scurlock, Carrie Ann

    1999-01-01

    Describes the construction of an inexpensive recirculating aquaculture system that can hold up to 46 pounds of fish, invertebrates, and mussels for classroom use. The system is versatile, requires little maintenance, and can be used for both teaching and research purposes. (WRM)

  11. In Situ Biotreatment of TBA with Recirculation/Oxygenation

    PubMed Central

    North, Katharine P.; Mackay, Douglas M.; Kayne, Julian S.; Petersen, Daniel; Rasa, Ehsan; Rastegarzadeh, Laleh; Holland, Reef B.; Scow, Kate M.

    2012-01-01

    The potential for in situ biodegradation of tert-butyl alcohol (TBA) by creation of aerobic conditions in the subsurface with recirculating well pairs was investigated in two field studies conducted at Vandenberg Air Force Base (VAFB). In the first experiment, a single recirculating well pair with bromide tracer and oxygen amendment successfully delivered oxygen to the subsurface for 42 days. TBA concentrations were reduced from approximately 500 μg/L to below the detection limit within the treatment zone and the treated water was detected in a monitoring transect several meters downgradient. In the second experiment, a site-calibrated model was used to design a double recirculating well pair with oxygen amendment, which successfully delivered oxygen to the subsurface for 291 days and also decreased TBA concentrations to below the detection limit. Methylibium petroleiphilum strain PM1, a known TBA-degrading bacterium, was detectable at the study site but addition of oxygen had little impact on the already low baseline population densities, suggesting that there was not enough carbon within the groundwater plume to support significant new growth in the PM1 population. Given favorable hydrogeologic and geochemical conditions, the use of recirculating well pairs to introduce dissolved oxygen into the subsurface is a viable method to stimulate in situ biodegradation of TBA or other aerobically-degradable aquifer contaminants. PMID:23358537

  12. High-Power Picosecond Pulse Recirculation for Inverse Compton Scattering

    NASA Astrophysics Data System (ADS)

    Jovanovic, Igor; Shverdin, Miro; Gibson, David; Brown, Curtis; Gronberg, Jeff

    2008-11-01

    In the next generation of linear colliders, inverse Compton scattering (ICS) of intense laser pulses on relativistic electron bunches will enable a mode of operation based on energetic γe and γγ collisions, with a significant complementary scientific potential. The efficiency of γ-ray generation via ICS is constrained by the Thomson scattering cross section, resulting in typical laser photon-to- γ efficiencies of <10 -9. Furthermore, repetition rates of the state-of-art high-energy short-pulse lasers are poorly matched with those available from electron accelerators. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. We propose and experimentally demonstrate an alternative, non-interferometric method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J [ I. Jovanovic, M. Shverdin, D. Gibson, and C. Brown, Nucl. Instrum. Methods A 578 160 (2007)]. ICS of recirculated Joule-level laser pulses is compatible with the proposed pulse structure for ILC and has a potential to produce unprecedented peak and average γ-ray brightness in the next generation of sources.

  13. Towards Non-thrombogenic Performance of Blood Recirculating Devices

    PubMed Central

    Bluestein, D.; Chandran, K. B.; Manning, K. B.

    2010-01-01

    Implantable blood recirculating devices have provided life saving solutions to patients with severe cardiovascular diseases. However, common problems of hemolysis and thromboembolism remain an impediment to these devices. In this article, we present a brief review of the work by several groups in the field that has led to the development of new methodologies that may facilitate achieving the daunting goal of optimizing the thrombogenic performance of blood recirculating devices. The aim is to describe work which pertains to the interaction between flow-induced stresses and the blood constituents, and that supports the hypothesis that thromboembolism in prosthetic blood recirculating devices is initiated and maintained primarily by the non-physiological flow patterns and stresses that activate and enhance the aggregation of blood platelets, increasing the risk of thromboembolism and cardioembolic stroke. Such work includes state-of-the-art numerical and experimental tools used to elucidate flow-induced mechanisms leading to thromboembolism in prosthetic devices. Following the review, the paper describes several efforts conducted by some of the groups active in the field, and points to several directions that should be pursued in the future in order to achieve the goal for blood recirculating prosthetic devices becoming more effective as destination therapy in the future. PMID:20131098

  14. Use of low temperature blowers for recirculation of hot gases

    DOEpatents

    Maru, H.C.; Forooque, M.

    1982-08-19

    An apparatus is described for maintaining motors at low operating temperatures during recirculation of hot gases in fuel cell operations and chemical processes such as fluidized bed coal gasification. The apparatus includes a means for separating the hot process gas from the motor using a secondary lower temperature gas, thereby minimizing the temperature increase of the motor and associated accessories.

  15. 33 CFR 159.127 - Safety coliform count: Recirculating devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Safety coliform count: Recirculating devices. 159.127 Section 159.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing §...

  16. 33 CFR 159.127 - Safety coliform count: Recirculating devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Safety coliform count: Recirculating devices. 159.127 Section 159.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing §...

  17. 33 CFR 159.127 - Safety coliform count: Recirculating devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Safety coliform count: Recirculating devices. 159.127 Section 159.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing §...

  18. 33 CFR 159.127 - Safety coliform count: Recirculating devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety coliform count: Recirculating devices. 159.127 Section 159.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing §...

  19. 33 CFR 159.127 - Safety coliform count: Recirculating devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Safety coliform count: Recirculating devices. 159.127 Section 159.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing §...

  20. Confined Turbulent Swirling Recirculating Flow Predictions. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Abujelala, M. T.

    1984-01-01

    Turbulent swirling flow, the STARPIC computer code, turbulence modeling of turbulent flows, the k-xi turbulence model and extensions, turbulence parameters deduction from swirling confined flow measurements, extension of the k-xi to confined swirling recirculating flows, and general predictions for confined turbulent swirling flow are discussed.

  1. Recirculation and growth of raindrops in simulated shallow cumulus

    NASA Astrophysics Data System (ADS)

    Naumann, A. K.; Seifert, A.

    2016-06-01

    This study investigates growth processes of raindrops and the role of recirculation of raindrops for the formation of precipitation in shallow cumulus. Two related cases of fields of lightly precipitating shallow cumulus are simulated using Large-Eddy Simulation combined with a Lagrangian drop model for raindrop growth and a cloud tracking algorithm. Statistics from the Lagrangian drop model yield that most raindrops leave the cloud laterally and then evaporate in the subsaturated cloud environmental air. Only 1%-3% of the raindrops contribute to surface precipitation. Among this subsample of raindrops that contribute to surface precipitation, two growth regimes are identified: those raindrops that are dominated by accretional growth from cloud water, and those raindrops that are dominated by selfcollection among raindrops. The mean cloud properties alone are not decisive for the growth of an individual raindrop but the in-cloud variability is crucial. Recirculation of raindrops is found to be common in shallow cumulus, especially for those raindrops that contribute to surface precipitation. The fraction of surface precipitation that is attributed to recirculating raindrops differs from cloud to cloud but can be larger than 50%. This implies that simple conceptual models of raindrop growth that neglect the effect of recirculation disregard a substantial portion of raindrop growth in shallow cumulus.

  2. An Inexpensive Recirculating Aquaculture System with Multiple Use Capabilities.

    ERIC Educational Resources Information Center

    Scurlock, Gerald Don, Jr.; Cook, S. Bradford; Scurlock, Carrie Ann

    1999-01-01

    Describes the construction of an inexpensive recirculating aquaculture system that can hold up to 46 pounds of fish, invertebrates, and mussels for classroom use. The system is versatile, requires little maintenance, and can be used for both teaching and research purposes. (WRM)

  3. Smart built-in test

    NASA Technical Reports Server (NTRS)

    Richards, Dale W.

    1990-01-01

    The work which built-in test (BIT) is asked to perform in today's electronic systems increases with every insertion of new technology or introduction of tighter performance criteria. Yet the basic purpose remains unchanged -- to determine with high confidence the operational capability of that equipment. Achievement of this level of BIT performance requires the management and assimilation of a large amount of data, both realtime and historical. Smart BIT has taken advantage of advanced techniques from the field of artificial intelligence (AI) in order to meet these demands. The Smart BIT approach enhances traditional functional BIT by utilizing AI techniques to incorporate environmental stress data, temporal BIT information and maintenance data, and realtime BIT reports into an integrated test methodology for increased BIT effectiveness and confidence levels. Future research in this area will incorporate onboard fault-logging of BIT output, stress data and Smart BIT decision criteria in support of a singular, integrated and complete test and maintenance capability. The state of this research is described along with a discussion of directions for future development.

  4. Smart built-in test

    NASA Astrophysics Data System (ADS)

    Richards, Dale W.

    1990-03-01

    The work which built-in test (BIT) is asked to perform in today's electronic systems increases with every insertion of new technology or introduction of tighter performance criteria. Yet the basic purpose remains unchanged -- to determine with high confidence the operational capability of that equipment. Achievement of this level of BIT performance requires the management and assimilation of a large amount of data, both realtime and historical. Smart BIT has taken advantage of advanced techniques from the field of artificial intelligence (AI) in order to meet these demands. The Smart BIT approach enhances traditional functional BIT by utilizing AI techniques to incorporate environmental stress data, temporal BIT information and maintenance data, and realtime BIT reports into an integrated test methodology for increased BIT effectiveness and confidence levels. Future research in this area will incorporate onboard fault-logging of BIT output, stress data and Smart BIT decision criteria in support of a singular, integrated and complete test and maintenance capability. The state of this research is described along with a discussion of directions for future development.

  5. Ozone degradation of alkylbenzene sulfonate in aqueous solutions using a stirred tank reactor with recirculation.

    PubMed

    Jurado-Alameda, Encarnación; Vicaria, José M; Altmajer-Vaz, Deisi; Luzón, Germán; Jiménez-Pérez, José L; Moya-Ramírez, Ignacio

    2012-01-01

    The degradation of linear alkylbenzene sulfonates (LAS) in aqueous solutions by ozone has been investigated. The ozonation process was performed in a stirred tank reactor with recirculation which simulates the clean-in-place process used in many industrial facilities. The gas-liquid mass transfer of ozone in a buffer solution at different temperatures (25-55°C) was also studied in the same device, revealing that ozone decomposition can be considered negligible under the experimental conditions assayed. The effect of the initial LAS concentration, temperature, and ozone concentration on the concentration of homologues and total LAS were analysed as a function of time. Both concentrations diminished with time, this effect being more significant when higher temperatures were assayed. The relative proportion of homologues shows that the homologues of higher chain length are degraded in a greater proportion than are the homologues with shorter chain lengths.

  6. Built-in self test

    NASA Astrophysics Data System (ADS)

    Jansen, B.; Vandegoor, A. J.

    1988-11-01

    Because of the increasing complexity of digital circuits, it is becoming more and more difficult to determine whether a circuit is correct or faulty. Faults in a circuit can hardly be detected just by looking at the outside what the reaction of the circuit is to a certain input sequence. Fault tolerant computing can be a solution. Built-In Self Test (BIST) techniques can also be used to verify whether the circuit is correct, not only during normal operation, but also during the early development periods. The result of using BIST techniques is a considerable reduction of time between design and the final product, and a reduction of maintenance time and cost. BIST is a test method of which the circuit can separate itself from the surrounding logic, and perform a test. After the self test, the circuit reports to the surrounding logic whether it is correct. The advantage of BIST is that it is a universal and systematic test method with a solid mathematical foundation. Based on the stuck-at fault model, it is possible to compute the fault coverage, which is the number of faults detected by the BIST method. The theory of BIST is described. A circuit is divided into combinational and sequential parts, which are tested separately. The sequential parts are tested with a so-called scan-path test. Alternative test methods to test the combinational parts are described. The method to compute the number of patterns needed to detect all faults with a certain probability as function of complexity of the circuit is given. The theory of CRC signature analyzers, and the probability of masking are also described and illustrated with some examples, which can directly be used in practice.

  7. Engine with exhaust gas recirculation system and variable geometry turbocharger

    DOEpatents

    Keating, Edward J.

    2015-11-03

    An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.

  8. Digital feedwater and recirculation flow control for GPUN Oyster Creek

    SciTech Connect

    Burjorjee, D. ); Gan, B. )

    1992-01-01

    This paper describes the digital system for feedwater and recirculation control that GPU Nuclear will be installing at Oyster Creek during its next outage - expected circa December 1992. The replacement was motivated by considerations of reliability and obsolescence - the analog equipment was aging and reaching the end of its useful life. The new system uses Atomic Energy of Canada Ltd.'s software platform running on dual, redundant, industrial-grade 386 computers with opto-isolated field input/output (I/O) accessed through a parallel bus. The feedwater controller controls three main feed regulating valves, two low flow regulating valves, and two block valves. The recirculation controller drives the five scoop positioners of the hydraulic couplers. The system also drives contacts that lock up the actuators on detecting an open circuit in their current loops.

  9. Research on leachate recirculation from different types of landfills

    SciTech Connect

    Wang Qi . E-mail: wangqi@craes.org.cn; Matsufuji, Yasushi; Dong Lu; Huang Qifei; Hirano, Fumiaki; Tanaka, Ayako

    2006-07-01

    Landfills can produce a great amount of leachate containing highly concentrated organic matter. This is especially true for the initial leachate from landfilled municipal solid wastes (MSW) that generally has concentrations of COD{sub Cr} and BOD{sub 5} up to 80,000 and 50,000 mg/L, respectively. The leachate could be disposed by means of recirculating technique, which decomposes the organics through the action of proliferating microorganisms and thereby purifies the leachate, and simultaneously accelerates organic decomposition through water saturation control. Data from experimental results indicated that leachate recirculating could reduce the organic concentration considerably, with a maximum reduction rate of COD{sub Cr} over 95%; and, using a semi-aerobic process, NH{sub 3}-N concentration of treated leachate could be under 10 mg/L. In addition, the organic concentration in MSW decreased greatly.

  10. Control of synchrotron radiation effects during recirculation with bunch compression

    SciTech Connect

    Douglas, David; Benson, Stephen; Li, Rui; Roblin, Yves; Tennant, Christopher; Krafft, Geoffrey; Terzic, Balsa; Tsai, Cheng

    2015-05-01

    Studies of beam quality during recirculation have been extended to an arc providing bunch compression with positive momentum compaction. It controls both incoherent and coherent synchrotron radiation (ISR and CSR) using methods including optics balance and generates little microbunching gain. We detail the dynamical basis for the design, discuss the design process, give an example, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of microbunching effects.

  11. Post-stenotic Recirculating Flow May Cause Hemodynamic Perforator Infarction

    PubMed Central

    Kim, Bum Joon; Ha, Hojin; Huh, Hyung Kyu; Kim, Guk Bae; Kim, Jong S.; Kim, Namkug; Lee, Sang-Joon; Kang, Dong-Wha; Kwon, Sun U.

    2016-01-01

    Background and Purpose The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI. Methods 3D-model of a BA stenosis was reconstructed with silicone compound using a 3D-printer based on the source image of HR-MRI. Working fluid seeded with fluorescence particles was used and the velocity of those particles was measured horizontally and vertically. Furthermore, microtubules were inserted into the posterior aspect of the model to measure the flow rates of perforators (pre-and post-stenotic areas). The flow rates were compared between the microtubules. Results A recirculating flow was observed from the post-stenotic area in both directions forming a spiral shape. The velocity of the flow in these regions of recirculation was about one-tenth that of the flow in other regions. The location of recirculating flow well corresponded with the area with low-signal intensity at the time-of-flight magnetic resonance angiography and the location of PPI. Finally, the flow rate through the microtubule inserted into the post-stenotic area was significantly decreased comparing to others (P<0.001). Conclusions Perforator infarction may be caused by a hemodynamic mechanism altered by stenosis that induces a recirculation flow. 3D-printed modeling and PIV are helpful understanding the hemodynamics of intracranial stenosis. PMID:26687122

  12. Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Turan, A.

    1985-01-01

    The hybrid-upwind finite difference schemes employed in generally available combustor codes possess excessive numerical diffusion errors which preclude accurate quantative calculations. The present study has as its primary objective the identification and assessment of an improved solution algorithm as well as discretization schemes applicable to analysis of turbulent viscous recirculating flows. The assessment is carried out primarily in two dimensional/axisymetric geometries with a view to identifying an appropriate technique to be incorporated in a three-dimensional code.

  13. Improved numerical methods for turbulent viscous recirculating flows

    NASA Technical Reports Server (NTRS)

    Vandoormaal, J. P.; Turan, A.; Raithby, G. D.

    1986-01-01

    The objective of the present study is to improve both the accuracy and computational efficiency of existing numerical techniques used to predict viscous recirculating flows in combustors. A review of the status of the study is presented along with some illustrative results. The effort to improve the numerical techniques consists of the following technical tasks: (1) selection of numerical techniques to be evaluated; (2) two dimensional evaluation of selected techniques; and (3) three dimensional evaluation of technique(s) recommended in Task 2.

  14. Tracking studies in eRHIC energy-recovery recirculator

    SciTech Connect

    Meot, F.; Brooks, S.; Ptitsyn, V.; Trbojevic, D.; Tsoupas, N.

    2015-07-13

    Beam and polarization tracking studies in eRHIC energy recovery electron recirculator are presented, based on a very preliminary design of the FFAG lattice. These simulations provide examples of some of the beam and spin optics aspects of the linear FFAG lattice concept and its application in eRHIC, they provide code benchmarking for synchrotron radiation and spin diffusion in addition, and pave the way towards end-to-end 6-D(phasespace)+3D(spin) tracking simulations.

  15. LONGITUDINAL DYNAMICS IN HIGH FREQUENCY FFAG RECIRCULATING ACCELERATORS.

    SciTech Connect

    BERG,J.S.

    2002-04-08

    A recirculating accelerator accelerates the beam by passing through accelerating cavities multiple times. An FFAG recirculating accelerator uses a single arc to connect the linacs together, as opposed to multiple arcs for the different energies. For most scenarios using high-frequency RF, it is impractical to change the phase of the RF on each pass, at least for lower energy accelerators. Ideally, therefore, the WAG arc will be isochronous, so that the particles come back to the same phase (on-crest) on each linac pass. However, it is not possible to make the FFAG arcs isochronous (compared to the RF period) over a large energy range. This paper demonstrates that one can nonetheless make an WAG recirculating accelerator work. Given the arc's path length as a function of energy and the number of turns to accelerate for, one can find the minimum voltage (and corresponding initial conditions) required to accelerate a reference particle to the desired energy. I also briefly examine how the longitudinal acceptance varies with the number of turns that one accelerates.

  16. Cyclone reactor with internal separation and axial recirculation

    DOEpatents

    Becker, F.E.; Smolensky, L.A.

    1988-07-19

    A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture is described. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combustor chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture may be tangentially withdrawn from the outlet end and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture. 10 figs.

  17. Cyclone reactor with internal separation and axial recirculation

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.

    1989-01-01

    A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combuston chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture of flue gas and ash may be tangentially withdrawn from the outlet end of the combustor chamber and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture.

  18. Hydroxyl time series and recirculation in turbulent nonpremixed swirling flames

    SciTech Connect

    Guttenfelder, Walter A.; Laurendeau, Normand M.; Ji, Jun; King, Galen B.; Gore, Jay P.; Renfro, Michael W.

    2006-10-15

    Time-series measurements of OH, as related to accompanying flow structures, are reported using picosecond time-resolved laser-induced fluorescence (PITLIF) and particle-imaging velocimetry (PIV) for turbulent, swirling, nonpremixed methane-air flames. The [OH] data portray a primary reaction zone surrounding the internal recirculation zone, with residual OH in the recirculation zone approaching chemical equilibrium. Modeling of the OH electronic quenching environment, when compared to fluorescence lifetime measurements, offers additional evidence that the reaction zone burns as a partially premixed flame. A time-series analysis affirms the presence of thin flamelet-like regions based on the relation between swirl-induced turbulence and fluctuations of [OH] in the reaction and recirculation zones. The OH integral time-scales are found to correspond qualitatively to local mean velocities. Furthermore, quantitative dependencies can be established with respect to axial position, Reynolds number, and global equivalence ratio. Given these relationships, the OH time-scales, and thus the primary reaction zone, appear to be dominated by convection-driven fluctuations. Surprisingly, the OH time-scales for these nominally swirling flames demonstrate significant similarities to previous PITLIF results in nonpremixed jet flames. (author)

  19. Pulsed power requirements for the Sandia recirculating electron beam linac

    SciTech Connect

    Tucker, W.K.; Shope, S.L.; Hasti, D.E.

    1987-01-01

    Compact, high gradient, linear induction accelerators may be achieved by recirculating the electron beam in phase with a repeating accelerating voltage. A two-cavity recirculating accelerator has been designed and operated in a single-pass mode. The prototype accelerator uses a 2.5-MV, 20-kA, 25-ns duration injector and an accelerating cavity that will produce a total accelerating voltage of 5.3 MV for four passes. The design of this machine involved key areas of development in pulsed power, specifically, low-jitter spark gaps and vacuum-liquid interfaces for bipolar electric fields. The extension of this technology to multiple-pulse machines will require advances in liquid dielectric breakdown strength and switch surface flashover, as well as additional improvements in lower inductance switching and vacuum-liquid interface flashover. This paper will discuss the recirculation concept, pulsed-power design parameters, machine scaling relationships that are valid for state-of-the-art and near-term pulsed-power parameters, and summarize the pulsed-power and beam transport experiments.

  20. Modeling of leachate recirculation using vertical wells in bioreactor landfills.

    PubMed

    Feng, Shi-Jin; Cao, Ben-Yi; Zhang, Xu; Xie, Hai-Jian

    2015-06-01

    Leachate recirculation (LR) in municipal solid waste (MSW) landfills operated as bioreactors offers significant economic and environmental benefits. The subsurface application method of vertical wells is one of the most common LR techniques. The objective of this study was to develop a novel two-dimensional model of leachate recirculation using vertical wells. This novel method can describe leachate flow considering the effects of MSW settlement while also accounting separately for leachate flow in saturated and unsaturated zones. In this paper, a settlement model for MSW when considering the effects of compression and biodegradation on the MSW porosity was adopted. A numerical model was proposed using new governing equations for the saturated and unsaturated zones of a landfill. The following design parameters were evaluated by simulating the recirculated leachate volume and the influence zones of waste under steady-state flow conditions: (1) the effect of MSW settlement, (2) the effect of the initial void ratio, (3) the effect of the injected head, (4) the effect of the unit weight, (5) the effect of the biodegradation rate, and (6) the effect of the compression coefficient. The influence zones of LR when considering the effect of MSW settlement are smaller than those when neglecting the effect. The influence zones and LR volume increased with an increase in the injection pressure head and initial void ratio of MSW. The proposed method and the calculation results can provide important insight into the hydrological behavior of bioreactor landfills.

  1. Mathematical model for analysis of recirculating vertical flow constructed wetlands.

    PubMed

    Sklarz, Menachem Y; Gross, Amit; Soares, M Ines M; Yakirevich, Alexander

    2010-03-01

    The recirculating vertical flow constructed wetland (RVFCW) was developed for the treatment of domestic wastewater (DWW). In this system, DWW is applied to a vertical flow bed through which it trickles into a reservoir located beneath the bed. It is then recirculated back to the root zone of the bed. In this study, a compartmental model was developed to simulate the RVFCW. The model, which addresses transport and removal kinetics of total suspended solids, 5-day biological oxygen demand and nitrogen, was fitted to kinetical results obtained from pilot field setups and a local sensitivity analysis was performed on the model parameters and operational conditions. This analysis showed that after 5h of treatment water quality is affected more by stochastic events than by the model parameter values, emphasizing the stability of the RVFCW system to large variations in operational conditions. Effluent quality after 1h of treatment, when the sensitivity analysis showed the parameter impacts to be largest, was compared to model predictions. The removal rate was found to be dependent on the recirculation rate. The predictions correlated well with experimental observations, leading to the conclusion that the proposed model is a satisfactory tool for studying RVFCWs. Copyright 2009 Elsevier Ltd. All rights reserved.

  2. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    With funding from the Building America Program, part of the U.S. Department of Energy Building Technologies Office, the Consortium for Advanced Residential Buildings (CARB) worked with BrightBuilt Home (BBH) to evaluate and optimize building systems. CARB’s work focused on a home built by Black Bros. Builders in Lincolnville, Maine (International Energy Conservation Code Climate Zone 6). As with most BBH projects to date, modular boxes were built by Keiser Homes in Oxford, Maine.

  3. Recirculation of Laser Power in an Atomic Fountain

    NASA Technical Reports Server (NTRS)

    Enzer, Daphna G.; Klipstein, WIlliam M.; Moore, James D.

    2007-01-01

    A new technique for laser-cooling atoms in a cesium atomic fountain frequency standard relies on recirculation of laser light through the atom-collection region of the fountain. The recirculation, accomplished by means of reflections from multiple fixed beam-splitter cubes, is such that each of two laser beams makes three passes. As described below, this recirculation scheme offers several advantages over prior designs, including simplification of the laser system, greater optical power throughput, fewer optical and electrical connections, and simplification of beam power balancing. A typical laser-cooled cesium fountain requires the use of six laser beams arranged as three orthogonal pairs of counter-propagating beams to decelerate the atoms and hold them in a three-dimensional optical trap in vacuum. Typically, these trapping/cooling beams are linearly polarized and are positioned and oriented so that (1) counter-propagating beams in each pair have opposite linear polarizations and (2) three of the six orthogonal beams have the sum of their propagation directions pointing up, while the other three have the sum of their propagation directions pointing down. In a typical prior design, two lasers are used - one to generate the three "up" beams, the other to generate the three "down" beams. For this purpose, the output of each laser is split three ways, then the resulting six beams are delivered to the vacuum system, independently of each other, via optical fibers. The present recirculating design also requires two lasers, but the beams are not split before delivery. Instead, only one "up" beam and one oppositely polarized "down" beam are delivered to the vacuum system, and each of these beams is sent through the collection region three times. The polarization of each beam on each pass through the collection region is set up to yield the same combination of polarization and propagation directions as described above. In comparison with the prior design, the present

  4. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air.

    PubMed

    Jung, Heejung S; Grady, Michael L; Victoroff, Tristan; Miller, Arthur L

    2017-07-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm(3), although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm(3). We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

  5. Investigation on inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet

    NASA Astrophysics Data System (ADS)

    Yang, Ce; Wang, Yingjun; Lao, Dazhong; Tong, Ding; Wei, Longyu; Liu, Yixiong

    2016-08-01

    The inlet recirculation characteristics of double suction centrifugal compressor with unsymmetrical inlet structures were studied in numerical method, mainly focused on three issues including the amounts and differences of the inlet recirculation in different working conditions, the circumferential non-uniform distributions of the inlet recirculation, the recirculation velocity distributions of the upstream slot of the rear impeller. The results show that there are some differences between the recirculation of the front impeller and that of the rear impeller in whole working conditions. In design speed, the recirculation flow rate of the rear impeller is larger than that of the front impeller in the large flow range, but in the small flow range, the recirculation flow rate of the rear impeller is smaller than that of the front impeller. In different working conditions, the recirculation velocity distributions of the front and rear impeller are non-uniform along the circumferential direction and their non-uniform extents are quite different. The circumferential non-uniform extent of the recirculation velocity varies with the working conditions change. The circumferential non-uniform extent of the recirculation velocity of front impeller and its distribution are determined by the static pressure distribution of the front impeller, but that of the rear impeller is decided by the coupling effects of the inlet flow distortion of the rear impeller, the circumferential unsymmetrical distribution of the upstream slot and the asymmetric structure of the volute. In the design flow and small flow conditions, the recirculation velocities at different circumferential positions of the mean line of the upstream slot cross-section of the rear impeller are quite different, and the recirculation velocities distribution forms at both sides of the mean line are different. The recirculation velocity distributions in the cross-section of the upstream slot depend on the static pressure

  6. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    NASA Astrophysics Data System (ADS)

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-07-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

  7. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    PubMed Central

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-01-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation. PMID:28781568

  8. Teaching about the Built Environment. ERIC Digest.

    ERIC Educational Resources Information Center

    Graves, Ginny

    Critical thinking, responsible citizenship, cultural literacy, social relevancy; these concerns of educators in the social studies can be addressed through teaching and learning about the built environment. The tangible structures that humans have created (bridges, houses, factories, farms, monuments) constitute the built environment. Objects in…

  9. Built Environment Education in Art Education.

    ERIC Educational Resources Information Center

    Guilfoil, Joanne K., Ed.; Sandler, Alan R., Ed.

    This anthology brings the study of the built environment, its design, social and cultural functions, and the criticism thereof into focus. Following a preface and introduction, 22 essays are organized in three parts. Part 1 includes: (1) "Landscape Art and the Role of the Natural Environment in Built Environment Education" (Heather…

  10. Built Environment Education in Art Education.

    ERIC Educational Resources Information Center

    Guilfoil, Joanne K., Ed.; Sandler, Alan R., Ed.

    This anthology brings the study of the built environment, its design, social and cultural functions, and the criticism thereof into focus. Following a preface and introduction, 22 essays are organized in three parts. Part 1 includes: (1) "Landscape Art and the Role of the Natural Environment in Built Environment Education" (Heather…

  11. Energy balance affected by electrolyte recirculation and operating modes in microbial fuel cells.

    PubMed

    Jacobson, Kyle S; Kelly, Patrick T; He, Zhen

    2015-03-01

    Energy recovery and consumption in a microbial fuel cell (MFC) can be significantly affected by the operating conditions. This study investigated the effects of electrolyte recirculation and operation mode (continuous vs sequence batch reactor) on the energy balance in a tubular MFC. It was found that decreasing the anolyte recirculation also decreased the energy recovery. Because of the open environment of the cathode electrode, the catholyte recirculation consumed 10 to 50 times more energy than the anolyte recirculation, and resulted in negative energy balances despite the reduction of the anolyte recirculation. Reducing the catholyte recirculation to 20% led to a positive energy balance of 0.0288 kWh m(-3). The MFC operated as a sequence batch reactor generated less energy and had a lower energy balance than the one with continuous operation. Those results encourage the further development of MFC technology to achieve neutral or even positive energy output.

  12. Facility Management's Role in Organizational Sustainability

    ERIC Educational Resources Information Center

    Adams, Gregory K.

    2013-01-01

    Facility managers have questions about sustainability. How do an organization's physical facilities--its built environment--and the management of them, influence the sustainability of the organization or institution as a whole? How important is Facility Management (FM) to the overall sustainability profile of an organization? Facility managers…

  13. Facility Management's Role in Organizational Sustainability

    ERIC Educational Resources Information Center

    Adams, Gregory K.

    2013-01-01

    Facility managers have questions about sustainability. How do an organization's physical facilities--its built environment--and the management of them, influence the sustainability of the organization or institution as a whole? How important is Facility Management (FM) to the overall sustainability profile of an organization? Facility managers…

  14. Recirculation-aeration: Bibliography for aquaculture. Bibliographies and literature of agriculture (Final)

    SciTech Connect

    Perschbacher, P.W.; Powell, R.V.; Freeman, D.W.; Lorio, W.J.; Hanfman, D.T.

    1993-08-01

    The bibliography includes literature citations through 1992 related to water recirculation and aeration in aquaculture. The focus is on filtration, aeration, and circulation techniques in various aquaculture situations.

  15. Recirculating sand filters for treatment of synthetic dairy parlor washings.

    PubMed

    Healy, M G; Rodgers, M; Mulqueen, J

    2004-01-01

    Land-spreading and spray irrigation are the most widely used practices for the disposal of dairy wastewaters in Ireland but in some cases there can be problems due to contamination of surface and ground water. The use of intermittent sand filtration has been suggested as an alternative treatment process. However, a single pass through a sand filter limits denitrification because of the absence of reducing conditions following nitrification and the lack of an available carbon source. This leads to poor total nitrogen (TN) reduction and an effluent that is high in nitrate nitrogen (NO3-N). This paper follows a previous paper in which two instrumented stratified sand filter columns (0.9 and 0.425 m deep, and both 0.3 m in diameter) were intermittently loaded with synthetic dairy parlor washings at a number of hydraulic loading rates, leading to a TN reduction of 27 to 41%. In the present study, under a chemical oxygen demand (COD) of 23.4 g m(-2) d(-1), the TN was reduced by 83.2% when three-quarters of the sand filter effluent was recirculated through an anoxic zone. This produced an effluent NO3-N concentration of 60 mg L(-1). With recirculation, the improvement in the removal of organic matter and ammonia N (NH4-N) is minimal. Recirculating sand filters appear to offer a mechanically simple and effective method for the removal of nitrogen from dairy parlor effluents and are a significant improvement over a single-pass sand filter.

  16. KENNEDY SPACE CENTER, FLA. - Dynamac employees Debbie Wells, Michelle Crouch and Larry Burns are silhouetted as they talk inside a conference room of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They have been transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - Dynamac employees Debbie Wells, Michelle Crouch and Larry Burns are silhouetted as they talk inside a conference room of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They have been transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  17. KENNEDY SPACE CENTER, FLA. - Dynamac employees (from left) Larry Burns, Debbie Wells and Michelle Crouch talk in a conference room of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They have been transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - Dynamac employees (from left) Larry Burns, Debbie Wells and Michelle Crouch talk in a conference room of the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They have been transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  18. KENNEDY SPACE CENTER, FLA. - Dynamac employees (from left) Larry Burns, Debbie Wells and Neil Yorio carry boxes of hardware into the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They are transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - Dynamac employees (from left) Larry Burns, Debbie Wells and Neil Yorio carry boxes of hardware into the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They are transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  19. KENNEDY SPACE CENTER, FLA. - Ivan Rodriguez, with Bionetics, and Michelle Crouch and Larry Burns, with Dynamac, carry boxes of equipment into the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They are transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

    NASA Image and Video Library

    2003-09-10

    KENNEDY SPACE CENTER, FLA. - Ivan Rodriguez, with Bionetics, and Michelle Crouch and Larry Burns, with Dynamac, carry boxes of equipment into the Space Life Sciences Lab (SLSL), formerly known as the Space Experiment Research and Processing Laboratory (SERPL). They are transferring equipment from Hangar L. The new lab is a state-of-the-art facility being built for ISS biotechnology research. Developed as a partnership between NASA-KSC and the State of Florida, NASA’s life sciences contractor will be the primary tenant of the facility, leasing space to conduct flight experiment processing and NASA-sponsored research. About 20 percent of the facility will be available for use by Florida’s university researchers through the Florida Space Research Institute.

  20. A recirculating hydroponic system for studying peanut (Arachis hypogaea L.)

    NASA Technical Reports Server (NTRS)

    Mackowiak, C. L.; Wheeler, R. M.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Sager, J. C. (Principal Investigator)

    1998-01-01

    Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.

  1. Status of the Fermilab electron cooling recirculation project

    SciTech Connect

    Thomas K Kroc

    2002-10-24

    The electron cooling project requires a high current electron beam with high reliability to provide the consistent cooling required by Fermilab's physics program. We are using a 5URE-2 Pelletron to provide this beam. The program is developing a high current DC recirculating electron beam with high recovery efficiency. The present layout uses 2 sets of tubes with acceleration, a 180{sup o} bend, and deceleration for a total of about 10 meters of beam line. The project's nominal operating parameters are .5 A at 4.3 MeV with the emission cathode immersed in a 200-600 G magnetic field.

  2. Bio-inspired robotic legs drive viscous recirculating flows

    NASA Astrophysics Data System (ADS)

    Takagi, Daisuke; Hayashi, Rintaro

    2015-11-01

    Crustaceans actuate multiple legs in a well-coordinated sequence to generate suitable flow for feeding and swimming. Inspired by tiny crustacean larvae operating at low Reynolds number, we study a scaled-up model in which slender rods oscillate independently in a bath of glycerol. Experiments reveal qualitatively different flow patterns depending on the phase and orientation of actuated rods. The observations are analyzed in the framework of slender-body theory for Stokes flow. This study shows that simple oscillatory motion of multiple legs can produce complex recirculating flows, with potential applications for mixing and pumping.

  3. Lymphopoiesis and lymphocyte recirculation in the sheep fetus

    PubMed Central

    1976-01-01

    The production and the circulation of lymphocytes has been examined in the sheep fetus where neither foreign antigen nor immunoglobulins occur. It was found that as the lymphoid organs increased in size during fetal life, the numbers and the output of lymphocytes in the thoracic duct lymph increased. The recirculating pool of lymphocytes was estimated to be 5.5 +/- 1.5 X 10(8) cells in fetal lambs 95-100 days of age, 5.7 +/- 1.2 X 10(9) cells in fetuses 130-135 days of age, and 1.2 +/0 9.3 X 10(10) cells in fetuses near to term. The rate of addition of lymphocytes to the recirculating pool was 3.2 +/- 1.9 X 10(6) cells/h in fetuses of 100 days and 3.4 +/- 0.9 X 10(7) cells/h in fetuses of 130 days of age. Lymphocytes recirculated from blood to lymph in fetuses; labeled cells injected into the blood stream reappeared in the thoracic duct lymph promptly and reached maximum levels around 12-18 h after they were injected. Labeled lymphocytes were detected subsequently in greatest numbers in the lymph nodes, particularly in the mesenteric lymph nodes and in the interfollicular areas of the Peyer's patches. Chronic drainage of thoracic duct lymph from fetuses in utero for periods of up to 36 days had no obvious effects on the growth or development of the fetus and only minimal effects on the content of lymphocytes in the various lymphoid tissues even though the number of cells in the blood and lymph were reduced to between 20-30% of normal levels. Thymectomy done in fetuses about 2 mo befor cannulation of the thoracic duct reduced the output of cells in the thoracic duct to about 25% of normal levels and caused a significant reduction in the content of lymphocytes in the various lymphoid tissues. Thymectomized fetal lambs subjected to thoracic duct drainage for periods up to 2 wk in utero had a similar complement of lymphocytes in their lymphoid tissues to intact thymectomized fetal lambs. Lymphocytes obtained from the thoracic duct lymph of lambs thymectomized 2 mo

  4. Gun and optics calculations for the Fermilab recirculation experiment

    SciTech Connect

    Kroc, T.

    1997-10-01

    Fermilab is investigating electron cooling to recycle 8 Gev antiprotons recovered from the Tevatron. To do so, it is developing an experiment to recirculate 2 Mev electrons generated by a Pelletron at National Electrostatics Corporation. This paper reports on the optics calculations done in support of that work. We have used the computer codes EGN2 and MacTrace to represent the gun area and acceleration columns respectively. In addition to the results of our simulations, we discuss some of the problems encountered in interfacing the two codes.

  5. A recirculating hydroponic system for studying peanut (Arachis hypogaea L.).

    PubMed

    Mackowiak, C L; Wheeler, R M; Stutte, G W; Yorio, N C; Ruffe, L M

    1998-07-01

    Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.

  6. Efficient random subcloning of DNA sheared in a recirculating point-sink flow system.

    PubMed Central

    Oefner, P J; Hunicke-Smith, S P; Chiang, L; Dietrich, F; Mulligan, J; Davis, R W

    1996-01-01

    Based on a high-performance liquid chromatographic pump, we have built a device that allows recirculation of DNA through a 63-microm orifice with ensuing fractionation to a minimum fragment size of approximately 300 base pairs. Residence time of the DNA fragments in the converging flow created by a sudden contraction was found to be sufficiently long to allow extension of the DNA molecules into a highly extended conformation and, hence, breakage to occur at midpoint. In most instances, 30 passages sufficed to obtain a narrow size distribution, with >90% of the fragments lying within a 2-fold size distribution. The shear rate required to achieve breakage was found to be inversely proportional to the 1.0 power of the molecular weight. Compared with a restriction digest, up to 40% of all fragments could be cloned directly, with only marginal improvements in cloning efficiency having been observed upon prior end repair with Klenow, T4 polymerase or T4 polynucleotide kinase. Sequencing revealed a fairly random distribution of the fragments. PMID:8918787

  7. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    DOEpatents

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  8. Principles of As-Built Engineering

    SciTech Connect

    Dolin, R.M.; Hefele, J.

    1996-11-01

    As-Built Engineering is a product realization methodology founded on the notion that life-cycle engineering should be based on what is actually produced and not on what is nominally designed. As-Built Engineering is a way of thinking about the production realization process that enables customization in mass production environments. It questions the relevance of nominal based methods of engineering and the role that tolerancing plays in product realization. As-Built Engineering recognizes that there will always be errors associated with manufacturing that cannot be controlled and therefore need to be captured in order to fully characterize each individual product`s unique attributes. One benefit of As-Built Engineering is the ability to provide actual product information to designers and analysts enabling them to verify their assumptions using actual part and assembly data. Another benefit is the ability to optimize new and re-engineered assemblies.

  9. Built Environment Analysis Tool: April 2013

    SciTech Connect

    Porter, C.

    2013-05-01

    This documentation describes the tool development. It was created to evaluate the effects of built environment scenarios on transportation energy and greenhouse gas (GHG) emissions. This documentation also provides guidance on how to apply the tool.

  10. KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building and NASA-KSC News Center. The flag is near the News Center. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

    NASA Image and Video Library

    2003-11-10

    KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building and NASA-KSC News Center. The flag is near the News Center. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

  11. KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. Some of the retrieval equipment can be seen on the rear deck. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

    NASA Image and Video Library

    2003-11-10

    KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. Some of the retrieval equipment can be seen on the rear deck. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

  12. KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

    NASA Image and Video Library

    2003-11-10

    KENNEDY SPACE CENTER, FLA. - The Freedom Star is berthed at the Turn Basin near the Vehicle Assembly Building. The ship has recently returned to KSC after refurbishment at Fort George Island, Fla., including new paint. Freedom Star is one of the solid rocket booster (SRB) retrieval ships built to recover the SRB casings released over the Atlantic Ocean after launch of a Space Shuttle. In addition to the SRBs, the ship recovers the drogue and main parachutes that slow the boosters’ speed before splashdown. The ships also tow the external tanks built at the Michoud Space Systems Assembly Facility near New Orleans to Port Canaveral, Fla. Freedom Star was brought to KSC today for a visit by NATO Parliamentarians.

  13. The Built Environment Predicts Observed Physical Activity

    PubMed Central

    Kelly, Cheryl; Wilson, Jeffrey S.; Schootman, Mario; Clennin, Morgan; Baker, Elizabeth A.; Miller, Douglas K.

    2014-01-01

    Background: In order to improve our understanding of the relationship between the built environment and physical activity, it is important to identify associations between specific geographic characteristics and physical activity behaviors. Purpose: Examine relationships between observed physical activity behavior and measures of the built environment collected on 291 street segments in Indianapolis and St. Louis. Methods: Street segments were selected using a stratified geographic sampling design to ensure representation of neighborhoods with different land use and socioeconomic characteristics. Characteristics of the built environment on-street segments were audited using two methods: in-person field audits and audits based on interpretation of Google Street View imagery with each method blinded to results from the other. Segments were dichotomized as having a particular characteristic (e.g., sidewalk present or not) based on the two auditing methods separately. Counts of individuals engaged in different forms of physical activity on each segment were assessed using direct observation. Non-parametric statistics were used to compare counts of physically active individuals on each segment with built environment characteristic. Results: Counts of individuals engaged in physical activity were significantly higher on segments with mixed land use or all non-residential land use, and on segments with pedestrian infrastructure (e.g., crosswalks and sidewalks) and public transit. Conclusion: Several micro-level built environment characteristics were associated with physical activity. These data provide support for theories that suggest changing the built environment and related policies may encourage more physical activity. PMID:24904916

  14. Linear fixed-field multipass arcs for recirculating linear accelerators

    DOE PAGES

    Morozov, V. S.; Bogacz, S. A.; Roblin, Y. R.; ...

    2012-06-14

    Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting themore » dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. Finally, we present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.« less

  15. Self-Recirculating Casing Treatment Concept for Enhanced Compressor Performance

    NASA Technical Reports Server (NTRS)

    Hathaway, Michael D.

    2002-01-01

    A state-of-the-art CFD code (APNASA) was employed in a computationally based investigation of the impact of casing bleed and injection on the stability and performance of a moderate speed fan rotor wherein the stalling mass flow is controlled by tip flow field breakdown. The investigation was guided by observed trends in endwall flow characteristics (e.g., increasing endwall aerodynamic blockage) as stall is approached and based on the hypothesis that application of bleed or injection can mitigate these trends. The "best" bleed and injection configurations were then combined to yield a self-recirculating casing treatment concept. The results of this investigation yielded: 1) identification of the fluid mechanisms which precipitate stall of tip critical blade rows, and 2) an approach to recirculated casing treatment which results in increased compressor stall range with minimal or no loss in efficiency. Subsequent application of this approach to a high speed transonic rotor successfully yielded significant improvements in stall range with no loss in compressor efficiency.

  16. Continuous hydroponic wheat production using a recirculating system

    NASA Technical Reports Server (NTRS)

    Mackowiak, C. L.; Owens, L. P.; Hinkle, C. R.; Prince, R. P.

    1989-01-01

    Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems.

  17. Design validation and performance of closed loop gas recirculation system

    NASA Astrophysics Data System (ADS)

    Kalmani, S. D.; Joshi, A. V.; Majumder, G.; Mondal, N. K.; Shinde, R. R.

    2016-11-01

    A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m2, with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C2H2F4), isobutane (iC4H10) and sulphur hexafluoride (SF6) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.

  18. Mixing and recirculation in two-layer exchange flows

    NASA Astrophysics Data System (ADS)

    StenströM, Petter

    2003-08-01

    Mixing and recirculation due to interfacial friction in two-layer exchange flows through topographic constrictions are investigated using a nonhydrostatic, three-dimensional numerical model. The simulated exchange flows are always lower than what inviscid hydraulic theory predicts; the reduction is greater for a contraction than for a sill, with intermediate values for sill-contraction combinations. A large fraction of a tracer flux in one layer is lost to the other layer from an inflow section at the entrance of the contraction (foot of the sill) up to the throat of the contraction (sill crest). For a contraction this fraction is about equal for the two layers, whereas for a sill the loss from the upper to the lower layer is about 6 times as high as the loss from the lower to the upper layer. Sill-contraction combinations show similar behavior to a contraction toward the dense reservoir and to a sill toward the light reservoir. The variation in recirculation fractions over a tidal cycle is small for flow over a sill, but greater for flow through a contraction. The peak rate of loss from a layer occurs when the flow in the other layer has its maximum, i.e., at maximum negative barotropic flow for the lower layer and at maximum positive barotropic flow for the upper layer.

  19. Interactive method for computation of viscous flow with recirculation

    NASA Technical Reports Server (NTRS)

    Brandeis, J.; Rom, J.

    1981-01-01

    An interactive method is proposed for the solution of two-dimensional, laminar flow fields with identifiable regions of recirculation, such as the shear-layer-driven cavity flow. The method treats the flow field as composed of two regions, with an appropriate mathematical model adopted for each region. The shear layer is computed by the compressible boundary layer equations, and the slowly recirculating flow by the incompressible Navier-Stokes equations. The flow field is solved iteratively by matching the local solutions in the two regions. For this purpose a new matching method utilizing an overlap between the two computational regions is developed, and shown to be most satisfactory. Matching of the two velocity components, as well as the change in velocity with respect to depth is amply accomplished using the present approach, and the stagnation points corresponding to separation and reattachment of the dividing streamline are computed as part of the interactive solution. The interactive method is applied to the test problem of a shear layer driven cavity. The computational results are used to show the validity and applicability of the present approach.

  20. In situ treatment of VOCs by recirculation technologies

    SciTech Connect

    Webb, O.F.; Siegrist, R.L.; Ally, M.R.; Sanford, W.E.; Kearl, P.M.; Zutman, J.L.

    1994-06-01

    Confronted with contaminated land from the world wars and the postwar industrialization period, German researchers and practicing professionals have worked to develop processes for effective environmental restoration. This presentation documents efforts by Oak Ridge National Laboratory (ORNL) researchers to (1) identify collaborators and German technologies exhibiting near-term potential for clean-up of volatile organic contaminated soil and groundwater at Department of Energy sites, (2) critically assess performance, and (3) inform interested agencies. The project was limited to identification and preliminary evaluation and included engineering computations, groundwater flow modeling, and treatment process modeling. Two processes were identified: (1) the vacuum vaporizer well/groundwater recirculation well and (2) the porous pipe/horizontal well (PP/HW). Both technologies induce a recirculation flow field in the aquifer and enable simultaneous down hole treatment of the aquifer and vadose zone. University of Karlsruhe researchers have demonstrated the UVB/GZB technology in shallow aquifers with moderately high saturated thickness and hydraulic conductivities. The PP/HW technology offers potential for VOC treatment in sites with thin aquifers or heterogeneities. This paper describes identified German technologies and includes critical evaluations of well performance, associated treatment processes, operating variables, and aquifer-well interactions.

  1. Harmonic Generation in the Multifrequency Recirculating Planar Magnetron

    NASA Astrophysics Data System (ADS)

    Exelby, S. C.; Greening, G. B.; Jordan, N. M.; Simon, D.; Zhang, P.; Lau, Y. Y.; Gilgenbach, R. M.

    2015-11-01

    The Multifrequency Recirculating Planar Magnetron (MFRPM) is a high power microwave source adapted from the Recirculating Planar Magnetrona, currently under investigation at the University of Michigan. The device features 2 dissimilar periodic structures allowing for the generation of (L-band) 1- and (S-band) 2-GHz high power microwave pulses simultaneously. These distinct frequencies offer the potential for variable coupling for defense applications, such as counter-IED. Experiments have been performed on the RPM, driven by the Michigan Electron Long Beam Accelerator with a Ceramic insulator (MELBA-C) using a -300kV, 1-10 kA, 0.3-1.0 us pulse applied to the cathode. Using the Mode Control Cathodeb and a coax-to-waveguide extraction system, the MFRPM has demonstrated simultaneous production of 20 MW at 1 GHz and 10 MW at 2 GHz. The L-band oscillator also produced both 2- and 4-GHz oscillations when the S-band oscillator turns on. These harmonics persist after the S-band oscillator turns off. Ongoing work will attempt to isolate these harmonics to measure the power accurately and confirm these observations. Supported by the Office of Naval Research grant no. N00014-13-1-0566 and L-3 Communications.

  2. Passive mode control in the recirculating planar magnetron

    SciTech Connect

    Franzi, Matthew; Gilgenbach, Ronald; Lau, Y. Y.; Greening, Geoff; Zhang, Peng; Hoff, Brad

    2013-03-15

    Preliminary experiments of the recirculating planar magnetron microwave source have demonstrated that the device oscillates but is susceptible to intense mode competition due, in part, to poor coupling of RF fields between the two planar oscillators. A novel method of improving the cross-oscillator coupling has been simulated in the periodically slotted mode control cathode (MCC). The MCC, as opposed to a solid conductor, is designed to electromagnetically couple both planar oscillators by allowing for the propagation of RF fields and electrons through resonantly tuned gaps in the cathode. Using the MCC, a 12-cavity anode block with a simulated 1 GHz and 0.26 c phase velocity (where c is the speed of light) was able to achieve in-phase oscillations between the two sides of the device in as little as 30 ns. An analytic study of the modified resonant structure predicts the MCC's ability to direct the RF fields to provide tunable mode separation in the recirculating planar magnetron. The self-consistent solution is presented for both the degenerate even (in phase) and odd (180 Degree-Sign out of phase) modes that exist due to the twofold symmetry of the planar magnetrons.

  3. Vortical Structures in Wall-Bounded Turbulent Flow with Recirculation

    NASA Astrophysics Data System (ADS)

    Imran Shah, Syed

    2011-12-01

    Hairpin or horse-shoe vortices are a widely-accepted feature of the wall-bounded flows. These vortical structures have mostly been studied in canonical flows. Relatively few studies have been conducted on the characteristics of the vortical structures in wall-bounded flows with adverse pressure gradient and still fewer on the detached flows with recirculation. In the present contribution, vortices have been educed using a DNS database of incompressible flow over a 2-dimensional surface bump in a converging-diverging channel at a Reynolds number Reτ of 617, based on the friction velocity at inlet. Vortices have been educed from the instantaneous velocity field in streamwise/wall-normal and spanwise/wall-normal planes using the signed swirling strength criterion. Vortex validation is done through a fit of the vortex velocity field to the Oseen vortex model. The effects of a strong adverse pressure gradient and flow reciruclation on the population density and sizes of the streamwise and spanwise-oriented vortices have been studied. It has been found that a strong adverse pressure gradient and flow recirculation leads to the generation of a new near-wall peak of small spanwise prograde vortex population. Furthermore, this peak of vortex density has been found to coincide and hence relate to the outward movement of the peak of streamwise rms velocity fluctuations typical of adverse pressure gradient wall-bounded turbulent flows.

  4. Electricity generation using continuously recirculated flow electrodes in reverse electrodialysis

    NASA Astrophysics Data System (ADS)

    Liu, Fei; Coronell, Orlando; Call, Douglas F.

    2017-07-01

    Capacitive flow electrode systems that generate electricity from salinity gradients are limited by low power densities, inefficient electrical current collection, and complex system operation. We show here the proof-of-concept that a single reverse electrodialysis cell using continuously recirculated activated carbon flow electrodes can generate uninterrupted electricity from an artificial sea/river water gradient. Power densities reached 61 ± 5.7 mW m-2 (normalized to total membrane surface area) and current densities 2.4 ± 0.13 A m-2 when a 10% by weight carbon loading was used with graphite plate current collectors. Using high-surface area graphite brush current collectors, maximum power densities increased more than 320% to 260 ± 8.7 mW m-2 and maximum current densities more than 400% to 14 ± 0.59 A m-2. The performance improvements were attributed to a more than 80% decrease in electrode resistances when brushes were used instead of plates. A control static capacitive electrode system obtained slightly higher average power densities (290 ± 8.7 mW m-2), but could not produce it continuously, highlighting the operational advantage of the recirculated flow electrode design.

  5. Microwave Power Measurements on the Recirculating Planar Magnetron

    NASA Astrophysics Data System (ADS)

    Jordan, N. M.; Franzi, M.; Greening, G. B.; Gilgenbach, R. M.; Simon, D. H.; Lau, Y. Y.; Hoff, B. W.; Luginsland, J. W.

    2014-10-01

    The recirculating planar magnetron (RPM) is a high power microwave generator that recirculates the beam in two-coupled, planar magnetrons. Experiments on the first L-band prototype have successfully produced 50--200 μs, 30-130 MW microwave pulses with instantaneous electronic efficiencies of up to 30% at approximately 1 GHz. The device is driven using MELBA-C, with parameters of: -300 kV for 0.3-1.0 μs, and 0.15-0.3 T axial magnetic fields. Recent RPM experiments have explored the effect of cathode surface treatment on the extracted microwave power, efficiency, and pulse width. This work utilized a proof of principle extraction system with antennas on the center vane of each oscillator to couple RF power into two, coaxial transmission lines. An advanced design, the Coaxial All Cavity Extractor, is in fabrication and will be discussed. Research supported by AFOSR Grant #FA9550-10-1-0104 and by AFRL.

  6. Interactive method for computation of viscous flow with recirculation

    NASA Technical Reports Server (NTRS)

    Brandeis, J.; Rom, J.

    1981-01-01

    An interactive method is proposed for the solution of two-dimensional, laminar flow fields with identifiable regions of recirculation, such as the shear-layer-driven cavity flow. The method treats the flow field as composed of two regions, with an appropriate mathematical model adopted for each region. The shear layer is computed by the compressible boundary layer equations, and the slowly recirculating flow by the incompressible Navier-Stokes equations. The flow field is solved iteratively by matching the local solutions in the two regions. For this purpose a new matching method utilizing an overlap between the two computational regions is developed, and shown to be most satisfactory. Matching of the two velocity components, as well as the change in velocity with respect to depth is amply accomplished using the present approach, and the stagnation points corresponding to separation and reattachment of the dividing streamline are computed as part of the interactive solution. The interactive method is applied to the test problem of a shear layer driven cavity. The computational results are used to show the validity and applicability of the present approach.

  7. Designing and Testing of Self-Cleaning Recirculating Zebrafish Tanks.

    PubMed

    Nema, Shubham; Bhargava, Yogesh

    2016-08-01

    Maintenance of large number of zebrafish in captive conditions is a daunting task. This can be eased by the use of recirculating racks with self-cleaning zebrafish tanks. Commercially available systems are costly, and compatibility of intercompany products has never been investigated. Although various cost-effective designs and methods of construction of custom-made recirculating zebrafish racks are available in literature, the design of self-cleaning zebrafish tanks is still not available. In this study, we report the design and method of construction of the self-cleaning unit, which can be fitted in any zebrafish tank. We validated the design by investigating sediment cleaning process in rectangular and cylindrical tank geometries using time lapse imaging. Our results suggest that for both tank geometries, the tanks fitted with self-cleaning unit provided superior sediment cleaning than the tanks fitted with overflow-drain unit. Although the self-cleaning unit could clean the sediment completely from both geometries over prolonged period, the cleaning of sediments was faster in the cylindrical tank than the rectangular tank. In conclusion, cost and efforts of zebrafish maintenance could be significantly reduced through the installation of our self-cleaning unit in any custom-made zebrafish tank.

  8. Design and installation of a high Reynolds number recirculating water tunnel

    NASA Astrophysics Data System (ADS)

    Daniel, Libin

    The High-Reynolds Number Fluid Mechanics Laboratory has recently been established at Oklahoma State University (OSU). The three primary components of the laboratory are 1) a recirculating water tunnel, 2) a multiphase pipe flow facility, and 3) a multi-scale flow visualization system. This thesis focuses on the design and fabrication of the water tunnel, which will be used for high-Reynolds number turbulent boundary layer research. Two main design criteria for the water tunnel were to achieve a momentum thickness based Reynolds number in excess of 104 and to have high optical access to the flow surfaces in the test section. This is being achieved with a 1 m. long test section and a maximum flow speed of 10 m/s. This Reynolds number was targeted to bridge the gap between typical university water tunnels (103) and the world's largest water tunnel facilities (105). The water tunnel is powered by a 150 hp motor and a 4500 gpm capacity centrifugal pump. The water tunnel is designed for a maximum operating pressure of 40 psi. This will make the facility a low cost option to perform high-Reynolds number aerodynamic and hydrodynamic tests. Improved flow imaging capability is a major advantage to liquid based fluid facilities because of the increased density for seeding and reduced field-of-view for equivalent Reynolds number. The laboratory's state-of-the-art flow visualization system can be used for time-resolved and phase averaged stereo- particle-image-velocimetry (sPIV), laser-induced-fluorescence, and high-speed imaging. Design provisions are also made to allow a multi-phase loop to share the pump and motor configuration of this water tunnel facility. The major design decisions that went into the design of the water tunnel facility are discussed. The design considerations that were taken into account for the test section, flow conditioning sections and the entire flow loop are discussed in greater detail. The final configuration and the technical drawings of the water

  9. Inactivation of bacteria using ultraviolet irradiation in a recirculating salmonid culture system

    USDA-ARS?s Scientific Manuscript database

    The objective of this research was to determine the ultraviolet (UV) irradiation dosages required to inactivate bacteria in a commercial-scale recirculating salmonid culture system. Research was conducted in the commercial-scale recirculating system used for Arctic char growout at the Conservation ...

  10. Unit process engineering for water quality control and biosecurity in marine water recirculating systems

    USDA-ARS?s Scientific Manuscript database

    High-intensity systems that treat and recirculate water must maintain a culture environment that can sustain near optimum fish health and growth at the design carrying capacity. Water recirculating systems that use centralized treatment systems can benefit from the economies of scale to decrease th...

  11. Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers

    SciTech Connect

    Barnard, J.J.; Cable, M.D.; Callahan, D.A.

    1996-02-06

    Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator.

  12. Built Environment Influences on Healthy Transportation Choices: Bicycling versus Driving

    PubMed Central

    Brauer, Michael; Setton, Eleanor M.; Teschke, Kay

    2010-01-01

    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form. PMID

  13. Built environment influences on healthy transportation choices: bicycling versus driving.

    PubMed

    Winters, Meghan; Brauer, Michael; Setton, Eleanor M; Teschke, Kay

    2010-12-01

    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form.

  14. Automated production holography test facility

    SciTech Connect

    Dutton, G.W.; Brown, F.A.; Bailey, L.R.

    1981-01-01

    A holographic nondestructive testing facility has been designed and built to measure the residual strain resulting from proof pressurization of stainless assemblies. The system is now in use as an in-line production test of these assemblies produced at Rockwell International's Rocky Flats Division. A complete high-pressure argon facility was built to achieve the necessary proof pressures. The entire holography and pressurizing operation is performed remotely and controlled automatically by means of a programmable controller using a microprocessor. Details of the holography optics, the pressurized gas system and the electronic controls are given. The holographic reconstruction and interference fringe counting and analysis capabilities of this facility are also discussed.

  15. Recirculation of Air Pollutants During Lake Breeze Events in Chicago

    NASA Astrophysics Data System (ADS)

    Schmeling, M.; Hodzic, A.; Massie, S. T.

    2009-12-01

    Chicago is located at the southwestern end of Lake Michigan and experiences lake breezes on a regular basis during the summer months. In order to study transport and evolution of air pollution during such lake breeze events reactive trace gases NOx and ozone were measured as well as aerosol samples collected in summer 2003. The aerosol samples were analyzed for major ionic species by ion chromatography and for elemental species by total reflection X-ray fluorescence spectrometry. Several lake breeze events occurred during the field collections with one set of events on June 30 and July 1, 2003 standing out due to high levels of NOx and some aerosol species such as nitrate, iron and lead. The fully coupled chemistry-meteorology model WRF/CHEM was applied to simulate atmospheric conditions on these two days. The simulations show that a temperature and wind field front developed in the course of the lake breeze event creating a local cell of about 150km in diameter. Air and pollutants trapped in this cell appear to be re-circulating above Chicago and western Lake Michigan. The model results provide important insight on the evolution of ozone precursors, photolysis rates and ozone production during transport above the lake, and allow for quantifying the influence of this recirculation on the observed levels of local pollutants in Chicago. Whereas the June 30/July 1, 2003 lake breeze seems to be very pronounced, other lake breeze situations showed also enhanced NOx and nitrate mixing ratios compared to non-lake breeze days. Interestingly ozone mixing ratios were found to be lower in average during lake breeze events as compared to non-lake breeze conditions. To understand the development of the local lake breeze cell and possible recirculation of pollutants we plan to simulate temperature, wind field and pollutant level on other lake breeze days as well. Satellite data from the moderate resolution imaging spectrometer (MODIS) and Atmospheric Infrared Sounder (AIRS) will

  16. Performance model of a recirculating stack nickel hydrogen cell

    NASA Technical Reports Server (NTRS)

    Zimmerman, Albert H.

    1994-01-01

    A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for

  17. Sanguinarine non- versus re-circulation during isolated heart perfusion--a Jekyll and Hyde effect?

    PubMed

    Webster, I; Smith, A; Lochner, A; Huisamen, B

    2014-10-01

    In isolated rat heart perfusion experiments, drug administration occurs via retrograde perfusion. This can be done in the non-recirculating mode (coronary effluent is discarded), or recirculating mode (coronary effluent is collected and reused). It was recently observed in our lab while using sanguinarine, an MKP-1 inhibitor, that there were differences in outcomes depending on the mode of recirculation used. Hearts from control (C); diet-induced obese (DIO) Wistar rats and their age matched controls (AMC) were perfused on the rig. Hearts received buffer (control) , insulin, sanguinarine, insulin + sanguinarine combination or methanol (vehicle) for 15 mins pre- and 10 mins post-ischemia in either a non- or re-circulating manner. Hearts were subjected to 15 mins global ischemia and 30 mins reperfusion. Mechanical function was documented pre- and post-ischemia . When not-recirculated , sanguinarine alone and in combination with insulin in C, DIO and AMC groups, caused a significant decrease in functional recovery during reperfusion. However, when the coronary effluent was recirculated, hearts perfused with sanguinarine or sanguinarine + insulin exhibited a significant recovery in function when compared with their non-recirculation counterparts (p < 0.01). No differences were seen with either control, insulin nor vehicle hearts. Sanguinarine elicited a vast improvement in perfusion outcomes when recirculated compared to non-recirculation . Since this was seen during perfusion only when sanguinarine was present, it is possible that recirculating reperfusion of the drug caused profound changes in its composition. More investigation is needed into the mechanisms involved. Thus caution should be exercised by researchers when designing a perfusion protocol for drug research.

  18. Knowledge from data in the built environment.

    PubMed

    Starkey, Christopher; Garvin, Chris

    2013-08-01

    Data feedback is changing our relationship to the built environment. Both traditional and new sources of data are developing rapidly, compelled by efforts to optimize the performance of human habitats. However, there are many obstacles to the successful implementation of information-centered environments that continue to hinder widespread adoption. This paper identifies these obstacles and challenges and describes emerging data-rich analytic techniques in infrastructure, buildings, and building portfolios. Further, it speculates on the impact that a robust data sphere may have on the built environment and posits that linkages to other data sets may enable paradigm shifts in sustainability and resiliency.

  19. Built Environment Energy Analysis Tool Overview (Presentation)

    SciTech Connect

    Porter, C.

    2013-04-01

    This presentation provides an overview of the Built Environment Energy Analysis Tool, which is designed to assess impacts of future land use/built environment patterns on transportation-related energy use and greenhouse gas (GHG) emissions. The tool can be used to evaluate a range of population distribution and urban design scenarios for 2030 and 2050. This tool was produced as part of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  20. Recirculating accelerator driver for a high-power free-electron laser: A design overview

    SciTech Connect

    Bohn, C.L.

    1997-06-01

    Jefferson Lab is building a free-electron laser (FEL) to produce continuous-wave (cw), kW-level light at 3-6 {mu}m wavelength. A superconducting linac will drive the laser, generating a 5 mA average current, 42 MeV energy electron beam. A transport lattice will recirculate the beam back to the linac for deceleration and conversion of about 75% of its power into rf power. Bunch charge will range up to 135 pC, and bunch lengths will range down to 1 ps in parts of the transport lattice. Accordingly, space charge in the injector and coherent synchrotron radiation in magnetic bends come into play. The machine will thus enable studying these phenomena as a precursor to designing compact accelerators of high-brightness beams. The FEL is scheduled to be installed in its own facility by 1 October 1997. Given the short schedule, the machine design is conservative, based on modifications of the CEBAF cryomodule and MIT-Bates transport lattice. This paper surveys the machine design.

  1. Use of fluorescence spectroscopy to control ozone dosage in recirculating aquaculture systems.

    PubMed

    Spiliotopoulou, Aikaterini; Martin, Richard; Pedersen, Lars-Flemming; Andersen, Henrik R

    2017-03-15

    The aim of this study was to investigate the potential of fluorescence spectroscopy to be used as an ozone dosage determination tool in recirculating aquaculture systems (RASs), by studying the relationship between fluorescence intensities and dissolved organic matter (DOM) degradation by ozone, in order to optimise ozonation treatment. Water samples from six different Danish facilities (two rearing units from a commercial trout RAS, a commercial eel RAS, a pilot RAS and two marine water aquariums) were treated with different O3 dosages (1.0-20.0 mg/L ozone) in bench-scale experiments, following which fluorescence intensity degradation was eventually determined. Ozonation kinetic experiments showed that RAS water contains fluorescent organic matter, which is easily oxidised upon ozonation in relatively low concentrations (0-5 mg O3/L). Fluorescence spectroscopy has a high level of sensitivity and selectivity in relation to associated fluorophores, and it is able to determine accurately the ozone demand of each system. The findings can potentially be used to design offline or online sensors based on the reduction by ozone of natural fluorescent-dissolved organic matter in RAS. The suggested indirect determination of ozone delivered into water can potentially contribute to a safer and more adequate ozone-based treatment to improve water quality.

  2. An adaptive image enhancement method for a recirculating aquaculture system.

    PubMed

    Zhou, Chao; Yang, Xinting; Zhang, Baihai; Lin, Kai; Xu, Daming; Guo, Qiang; Sun, Chuanheng

    2017-07-24

    Due to the low and uneven illumination that is typical of a recirculating aquaculture system (RAS), visible and near infrared (NIR) images collected from RASs always have low brightness and contrast. To resolve this issue, this paper proposes an image enhancement method based on the Multi-Scale Retinex (MSR) algorithm and a greyscale nonlinear transformation. First, the images are processed using the MSR algorithm to eliminate the influence of low and uneven illumination. Then, the normalized incomplete Beta function is used to perform a greyscale nonlinear transformation. The function's optimal parameters (α and β) are automatically selected by the particle swarm optimization (PSO) algorithm based on an image contrast measurement function. This adaptive image enhancement method is compared with other classic enhancement methods. The results show that the proposed method greatly improves the image contrast and highlights dark areas, which is helpful during further analysis of these images.

  3. Dynamics of microorganism populations in recirculating nutrient solutions

    NASA Technical Reports Server (NTRS)

    Strayer, R. F.

    1994-01-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet Controlled Ecological Life Support Systems (CELSS) tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  4. Recycling crop residues for use in recirculating hydroponic crop production

    NASA Technical Reports Server (NTRS)

    Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

    1996-01-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

  5. Dynamics of microorganism populations in recirculating nutrient solutions

    NASA Technical Reports Server (NTRS)

    Strayer, R. F.

    1994-01-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  6. Computation of recirculating compressible flow in axisymmetric geometries

    SciTech Connect

    Isaac, K.M.; Nejad, A.S.

    1985-01-01

    A computational study of compressible, turbulent, recirculating flow in axisymmetric geometries is reported in this paper. The SIMPLE algorithm was used in the differencing scheme and the k-epsilon model for turbulence was used for turbulence closure. Special attention was given to the specification of the boundary conditions. The study revealed the significant influence of the boundary conditions on the solution. The eddy length scale at the inlet to the solution domain was the most uncertain parameter in the specification of the boundary conditions. The predictions were compared with the recent data based on laser velocimetry. The two are seen to be in good agreement. The present study underscores the need to have a more reliable means of specifying the inlet boundary conditions for the k-epsilon turbulence model.

  7. Recycling crop residues for use in recirculating hydroponic crop production

    NASA Technical Reports Server (NTRS)

    Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

    1996-01-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

  8. Successful water reuse in open recirculating cooling systems

    SciTech Connect

    Vaska, M.; Lee, B.

    1994-12-31

    Water reuse in open recirculating cooling water systems is becoming increasingly prevalent in industry. Reuse can incorporate a number of varied approaches with the primary goal being water conservation. Market forces driving this trend include scarcity of fresh water makeup sources and higher costs associated with pretreatment of natural waters. Utilization of reuse water for cooling tower makeup has especially detrimental effects on corrosion and deposit rates. Additionally, once the reuse water is cycled and treated with inhibitors, dispersants and microbiocides, acceptability for discharge to a public waterway can be a concern. The task for water treatment suppliers is to guide industry in the feasibility and procedures for successfully achieving these goals. This paper focuses particularly on reuse of municipal wastewater for cooling tower makeup and explores techniques which have been found especially effective. Case histories are described where these concepts have been successfully applied in practice.

  9. Dynamics of microorganism populations in recirculating nutrient solutions

    NASA Astrophysics Data System (ADS)

    Strayer, R. F.

    1994-11-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  10. Microbial diversity of biological filters in recirculating aquaculture systems.

    PubMed

    Schreier, Harold J; Mirzoyan, Natella; Saito, Keiko

    2010-06-01

    Development of environmentally sustainable farming of marine and freshwater species using recirculating aquaculture systems (RASs) requires a complete understanding of the biological component involved in wastewater treatment. This component integrates biofilters composed of microbial communities whose structure, dynamics, and activities are responsible for system success. Engineering highly efficient, environmentally sound, disease-free, and economically viable systems necessitates a thorough knowledge of microbial processes involved in all facets of RAS biofilters and has only recently been the focus of comprehensive studies. These studies have included the application of molecular tools to characterize community diversity and have identified key processes useful for improving system performance. In this paper we summarize the current understanding of the microbial diversity and physiology of RAS biofilters and discuss directions for future studies.

  11. Energy stability in recirculating, energy-recovering linacs

    SciTech Connect

    Merminga, L.; Bisognano, J.J.; Delayen, J.R.

    1996-07-01

    Recirculating, energy-recovering linacs can be used as driver accelerators for high power FELs. Instabilities which arise from fluctuations of the cavity fields are investigated. Energy changes can cause beam loss on apertures, or, when coupled to M{sub 56}, phase oscillations. Both effects change the beam induced voltage in the cavities and can lead to unstable variations of the accelerating field. Stability analysis for small perturbations from equilibrium is performed and threshold currents are determined. Furthermore, the analytical model is extended to include amplitude and phase feedback, with the transfer function in the feedback path presently modeled as a low-pass filter. The feedback gain and bandwidth required for stability are calculated for the high power UV FEL proposed for construction at CEBAF. 4 refs.

  12. RECENT PROGRESS TOWARD A MUON RECIRCULATING LINEAR ACCELERATOR

    SciTech Connect

    Slawomir Bogacz, Vasiliy Morozov, Yves Roblin, Kevin Beard

    2012-07-01

    Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchnotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadruopoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.

  13. Dynamics of microorganism populations in recirculating nutrient solutions

    NASA Technical Reports Server (NTRS)

    Strayer, R. F.

    1994-01-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet Controlled Ecological Life Support Systems (CELSS) tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  14. Experiments With Recirculating Target for F-18 Production

    NASA Astrophysics Data System (ADS)

    Kiselev, M. Y.

    2003-08-01

    Approximately 10 ml of O-18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F-18 in relation to consumed O-18 water material. It can also increase productivity by eliminating idle periods for re-filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target.

  15. Capture of CO2 From Recirculating Flue Gas Boilers

    SciTech Connect

    Ochs, Thomas L.

    2003-01-01

    The possible need for an economical method for the separation of CO2 from flue gas adds a new set of challenges to power plant design, construction, operation, and maintenance. Many of the new requirements of CO2 separation are similar in nature to those addressed by the mature chemical engineering processes used in petroleum refining and industrial chemical production. Chemical engineering processes are regularly used to separate heterogeneous vapors in processes such as the fractionation of hydrocarbons or the separation of the components of air. This paper addresses the application of chemical engineering processes to the mixtures of gases and vapors found in the flue gas of recirculating boilers. Adaptation of these techniques can lead to a reduction in the energy required to capture CO2.

  16. Recycling crop residues for use in recirculating hydroponic crop production.

    PubMed

    Mackowiak, C L; Garland, J L; Sager, J C

    1996-12-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

  17. Dynamics of microorganism populations in recirculating nutrient solutions.

    PubMed

    Strayer, R F

    1994-11-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  18. Releasing behavior of copper in recirculated bioreactor landfill.

    PubMed

    Long, Yu-Yang; Hu, Li-Fang; Jiang, Chen-Jing; Fang, Cheng-Ran; Wang, Feng-Ping; Shen, Dong-Sheng

    2009-04-01

    The purpose of this study was to determine the releasing behavior of copper in municipal solid waste (MSW) in landfill with respect to refuse and leachate as an inseparable system. Two simulated bioreactor landfills, one with leachate recirculation and the other without, were operated in room temperature for 320 days. Copper in refuse showed behaviors of staggered migration and retention, which corresponded with the degradation process of landfill obviously. The significant different amounts of Cu2+ leached out from refuse into leachate of two landfills were 24.74 mg and 118.53 mg after 320 days' operation, respectively. It also reflected the releasing behavior of copper in landfill refuse at different stage accordingly. The results confirmed that the refuse in landfill had high potential of secondary pollution after closure.

  19. TRACG Simulation of Drywell Gas Recirculation System in ESBWR

    SciTech Connect

    Cheung, Yee K.; Rao, Atambir S.

    2002-07-01

    This paper presents the results of a parametric study on the mitigating effects of the Drywell Gas Recirculation System (DGRS) in ESBWR during postulated LOCA and severe accidents. The post-accident containment pressure depends on the sum of the partial pressure from non-condensable gases and partial steam pressure inside the wet-well airspace. Results of parametric studies show that, with the activation of DGRS: (1) The containment pressure continues to reduce due to the redistribution of non-condensable gases from the wet-well back to the drywell; (2) The DGRS can be designed in a 'portable' fashion; (3) The Current ESBWR meets the design requirement with significant margin using only passive safety systems, and the margin increases considerably with the activation of DGRS. (authors)

  20. Evaluation of recirculating sand filter in a cold climate.

    PubMed

    Christopherson, S H; Anderson, J L; Gustafson, D M

    2005-01-01

    Approximately 30% of Minnesota's residents rely on onsite technologies for their wastewater treatment. There is a growing need for 'alternative' technologies to aid in treatment for difficult sites and sensitive environmental areas. Recirculating sand filters (RSFs) have been used since the 1970s for small communities with flows > 20,000 L per day, but use for small flow application (< 5,000 L/d) has been growing due to its small land use requirement. A research site was developed in southern Minnesota in 1995 to test alternative technologies, including two RSFs. In addition, in 1998, two RSFs were added to existing residential soil treatment systems that were having problems because of inadequate separation and fill soil conditions. All RSFs in this study used 0.6 metres of coarse sand for treatment, were loaded at approximately 204 L per day per square metre (5 gallons per square foot per day) and a recirculation rate of 5:1. All RSFs have effectively reduced Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), Fecal Coliform (FC) and Nutrients (nitrogen and phosphorus). These systems are able to achieve secondary effluent treatment levels for BOD5 and TSS. The median FC reduction was 90% with a value of 5.7 E4 cfu/100 mL, indicating additional treatment is necessary to protect health and the environment. The RSFs consistently removed 25% or more total phosphorus (TP) and 40% or more total nitrogen (TN). The RSFs did not show significantly decreased performance during the winter months. Two of the RSFs receiving rather high strength domestic waste were able to reduce a greater percentage of total nitrogen, indicated that the addition of carbon from the high strength waste is a benefit resulting in greater TN removal.

  1. Traffic and proliferative responses of recirculating lymphocytes in fetal calves.

    PubMed Central

    Hein, W R; Shelton, J N; Simpson-Morgan, M W; Morris, B

    1988-01-01

    The thoracic duct or efferent prescapular duct was cannulated in four fetal calves aged 121-259 days post-conception. The duration of lymph flow ranged from 2 to 20 days and the mean flow rates sustained over these collection periods varied from 5.4 to 48.8 ml/hr. Lymphocyte output ranged from 4.4 x 10(6) cells/hr in thoracic duct lymph from a 121-day fetus to 3.9 x 10(8) cells/hr in efferent prescapular lymph from a 259-day fetus. The circulating lymphocyte pool in fetal calves of about 120 and 190 days gestational age was calculated to contain, respectively, 4 x 10(8) cells and 2 x 10(10) cells. The proportion of lymphocytes bearing surface immunoglobulin detected in fetal lymph ranged from 2.1% to 8.7%. Recirculating lymphocytes from fetal calves produced strong proliferative responses when stimulated by T-cell mitogens but responded poorly to B-cell mitogens. Fetal lymphocytes also responded to stimulation by allogeneic cells and stimulated other cells to proliferate during mixed lymphocyte culture. When stimulated with Con A, fetal lymphocytes secreted IL-2 to a degree that was indistinguishable from the secretory behaviour of lymphocytes from adult animals. The results presented in this paper show that chronic lymphatic fistulae can be established successfully in fetal calves to give access to recirculating lymphocytes. This provides a new experimental approach for studying the development of the bovine immune system. PMID:2971606

  2. Recirculation of the Canary Current in fall 2014

    NASA Astrophysics Data System (ADS)

    Hernández-Guerra, Alonso; Espino-Falcón, Elisabet; Vélez-Belchí, Pedro; Dolores Pérez-Hernández, M.; Martínez-Marrero, Antonio; Cana, Luis

    2017-10-01

    Hydrographic measurements together with Ship mounted Acoustic Doppler Current Profilers and Lowered Acoustic Doppler Current Profilers (LADCP) obtained in October 2014 are used to describe water masses, geostrophic circulation and mass transport of the Canary Current System, as the Eastern Boundary of the North Atlantic Subtropical Gyre. Geostrophic velocities are adjusted to velocities from LADCP data to estimate an initial velocity at the reference layer. The adjustment results in a northward circulation at the thermocline layers over the African slope from an initial convergent flow. Final reference velocities and consequently absolute circulation are estimated from an inverse box model applied to an ocean divided into 13 neutral density layers. This allows us to evaluate mass fluxes consistent with the thermal wind equation and mass conservation. Ekman transport is estimated from the wind data derived from the Weather Research and Forecasting model. Ekman transport is added to the first layer and adjusted with the inverse model. The Canary Current located west of Lanzarote Island transports to the south a mass of - 1.5 ± 0.7 Sv (1 Sv = 106 m3 s- 1 ≈ 109 kg s- 1) of North Atlantic Central Water at the surface and thermocline layers ( 0-700 m). In fall 2014, hydrographic data shows that the Canary Current in the thermocline (below at about 80 m depth to 700 m) recirculates to the north over the African slope and flows through the Lanzarote Passage. At intermediate layers ( 700-1400 m), the Intermediate Poleward Undercurrent transports northward a relatively fresh Antarctic Intermediate Water in the range of 0.8 ± 0.4 Sv through the Lanzarote Passage and west of Lanzarote Island beneath the recirculation of the Canary Current.

  3. Oral bioavailability and enterohepatic recirculation of otilonium bromide in rats.

    PubMed

    Shin, Beom Soo; Kim, Jung Jun; Kim, John; Hu, Sul Ki; Kim, Hyoung Jun; Hong, Seok Hyun; Kim, Han Kyung; Lee, Hye Suk; Yoo, Sun Dong

    2008-01-01

    This study was conducted to examine the oral bioavailability and the possibility of enterohepatic recirculation of otilonium bromide in rats. A sensitive LC/MS/MS assay (LLOQ 0.5 ng/mL) was developed for the determination of otilonium and applied to i.v. and oral administration studies in bile duct cannulated (BDC) and non-BDC rats. After i.v. injection to BDC rats (1 mg/ kg as otilonium), average t(1/2), CL, Vz and AUC were 7.9 +/- 1.9 h, 8.7 +/- 3.1 mL/min/kg, 5.7 +/- 1.4 L/kg and 2,088 +/- 676 ng h/mL, respectively, and these values were comparable to those found in non-BDC rats. The percentages of i.v. dose excreted unchanged in bile and urine in BDC rats were 11.6 +/- 3.0 and 3.1 +/- 0.7%, respectively. Upon oral administration to non-BDC rats (20 mg/kg as otilonium), t(1/2), Cmax, Tmax and AUC were 6.4 +/- 1.3 h, 182.8 +/- 44.6 ng/mL, 1.9 +/- 1.6 h and 579 +/- 113 ng h/mL, respectively. The absolute oral bioavailability was low (1.1%), while the drug was preferentially distributed to gastrointestinal tissues. A secondary peak was observed in the serum concentration-time profiles in non-BDC rats following both i.v. and oral administration, indicating that otilonium bromide was subject to enterohepatic recirculation.

  4. Fixed Field Alternating Gradient recirculator for heavy ion fusion

    SciTech Connect

    Paul, A.C.; Neil, V.K.

    1991-03-01

    A heavy ion fusion driver is considered in which a beam is passed repeatedly through a LIA (linear induction accelerator) by recirculating with two spiral sector FFAG (Fixed Field Alternating Gradient) 180 degree bends. The driver consists of three such rings: a 10--100 MeV low energy ring (LER), a 100--1000 MeV medium energy ring (MER), and a 1--10 GeV high energy ring (HER). Using a scaling field of 14 kG and taking the length of the straight sections to equal the path length in the bends, the circumference of the three rings would be 187, 590, and 1890 meters. Four matching sections in each of the three rings provide the interface between the two straight sections accommodating the LIA and the FFAG bends. These matching sections consist of dipoles which provide a dispersion free match between the linear induction accelerator and the energy dependent equilibrium orbits of the FFAG ring. The advantage in the use of the spiral sector FFAG over other recirculator concepts is that the fields are time invariant. This removes the problems associated with time dependent field penetration into the vacuum chamber and the large amount of energy which must be expended to change the magnetic field on the small time scale associated with the required pulse repetition frequency. The disadvantage, as we show in this work is the relatively weak alternating gradient focusing. The FFAG will not accommodate the level of beam current possible in a separate function lattice of bending magnets and quadrupoles.

  5. The Impact of Tropical Recirculation on Stratospheric Mean Age

    NASA Astrophysics Data System (ADS)

    Strahan, S. E.; Schoeberl, M. R.; Steenrod, S. D.

    2008-05-01

    Ten years ago, many models failed in the comparison with mean age at 20 km, but with recent improvements in advection schemes, many models now have reasonable mean age in the lower stratosphere. However, a good mean age alone does not validate model transport because compensating transport errors can conspire to give reasonable mean age in spite of poor representation of physical processes. A better diagnostic is the age spectrum The first peak of the age spectrum reveals the most common transit time to a given point in the stratosphere (the modal age) while the mean of the age spectrum reflects the average transit time. The separation of the mean and modal ages is a measure of the integrated effects of mixing during transport. In the tropical lower stratosphere, horizontal mixing across the subtropics is weak and transport is dominated by vertical advection. Using a 15-yr time series of AURA MLS and UARS HALOE tropical water vapor, Schoeberl et al. [2008] determined the phase speed of the water vapor anomaly, providing an empirical determination of modal age. Together, the modal age and mean age, derived from CO2 and SF6, give the two main components of the age spectrum. We use the empirically derived mean and modal ages in the tropical stratosphere, 18-35 km, to separately diagnose mean vertical advection and tropical recirculation in the GEOS4-GCM. We link the behavior of the age tracer to CH4 and demonstrate how tropical age affects age in the Antarctic. We show that tropical vertical advection in the GEOS4-GCM is very well simulated and that its young tropical mean age stems from too much tropical isolation. A related set of meteorological fields from the GEOS4-DAS has older mean age as a result of greater tropical recirculation. A simulation using GEOS4-DAS fields has better agreement with HALOE CH4 in the Antarctic, supporting the hypothesis that deficiencies in tropical age affect age throughout the stratosphere.

  6. Combined-cycle plant built in record time

    SciTech Connect

    1995-04-01

    This article reports that this low-cost cogeneration plant meets residential community`s environmental concerns with noise minimization, emissions control, and zero wastewater discharge. Supplying electricity to the local utility and steam to two hosts, the Auburndale cogeneration facility embodies the ``reference plant`` design approach developed by Westinghouse Power Generation (WPG), Orlando, Fla. With this approach customers meet their particular needs by choosing from a standard package of plant equipment and design options. Main goals of the concept are reduced construction time efficient and reliable power generation, minimal operating staff, and low cost. WPG built the plant on a turnkey basis for Auburndale Power Partners Limited Partnership (APP). APP is a partially owned subsidiary of Mission Energy, a California-based international developer and operator of independent-power facilities. The cogeneration facility supplies 150 MW of electric power to Florida Power Corp and exports 120,000 lb/hr of steam to Florida Distillers Co and Coca-Cola Foods.

  7. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    SciTech Connect

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to determine if WSAC technology could cool process water at cycles of concentration considered highly scale forming for mechanical draft cooling towers. At the completion of testing, there was no visible scale on the heat transfer surfaces and cooling was sustained throughout the test period. The application of the WARMF decision framework to the San Juan Basis showed that drought and increased temperature impact water availability for all sectors (agriculture, energy, municipal, industry) and lead to critical shortages. WARMF-ZeroNet, as part of the integrated ZeroNet decision support system, offers stakeholders an integrated approach to long-term water management that balances competing needs of existing water users and economic growth under the constraints of limited supply and potential climate change.

  8. Simple and Cooperatively Built Wave Motion Demonstrator

    ERIC Educational Resources Information Center

    Cortel, Adolf

    2006-01-01

    Some designs of simple wave demonstration devices have been described in this journal and elsewhere. A new simple model can be built using only dowels, binder clips, and loops of thread. Not only can it be easily assembled, stored, or disassembled, but also all the students in a class can cooperate in its building by connecting successive pieces…

  9. Simple and Cooperatively Built Wave Motion Demonstrator

    ERIC Educational Resources Information Center

    Cortel, Adolf

    2006-01-01

    Some designs of simple wave demonstration devices have been described in this journal and elsewhere. A new simple model can be built using only dowels, binder clips, and loops of thread. Not only can it be easily assembled, stored, or disassembled, but also all the students in a class can cooperate in its building by connecting successive pieces…

  10. Multichannel Analyzer Built from a Microcomputer.

    ERIC Educational Resources Information Center

    Spencer, C. D.; Mueller, P.

    1979-01-01

    Describes a multichannel analyzer built using eight-bit S-100 bus microcomputer hardware. The output modes are an oscilloscope display, print data, and send data to another computer. Discusses the system's hardware, software, costs, and advantages relative to commercial multichannels. (Author/GA)

  11. Schooling Built on the Multiple Intelligences

    ERIC Educational Resources Information Center

    Kunkel, Christine D.

    2009-01-01

    This article features a school built on multiple intelligences. As the first multiple intelligences school in the world, the Key Learning Community shapes its students' days to include significant time in the musical, spatial and bodily-kinesthetic intelligences, as well as the more traditional areas of logical-mathematical and linguistics. In…

  12. [Interpreting Historic Sites & the Built Environment.

    ERIC Educational Resources Information Center

    Yellis, Ken, Ed.

    1985-01-01

    This issue focuses on the interpretation of built environments, from Washington Irving's 19th century home in Tarrytown, New York, to structures in contemporary Chicago. Barbara Carson, Margaret Piatt, and Renee Friedman discuss the interpretation of interior and exterior spaces and explain how to teach history with objects instead of teaching the…

  13. Schooling Built on the Multiple Intelligences

    ERIC Educational Resources Information Center

    Kunkel, Christine D.

    2009-01-01

    This article features a school built on multiple intelligences. As the first multiple intelligences school in the world, the Key Learning Community shapes its students' days to include significant time in the musical, spatial and bodily-kinesthetic intelligences, as well as the more traditional areas of logical-mathematical and linguistics. In…

  14. Built Environment Correlates of Walking: A Review

    PubMed Central

    Saelens, Brian E.; Handy, Susan L.

    2010-01-01

    Introduction The past decade has seen a dramatic increase in the empirical investigation into the relations between built environmental and physical activity. To create places that facilitate and encourage walking, practitioners need an understanding of the specific characteristics of the built environment that correlate most strongly with walking. This paper reviews evidence on the built environment correlates with walking. Method Included in this review were 13 reviews published between 2002 and 2006 and 29 original studies published in 2005 and up through May 2006. Results were summarized based on specific characteristics of the built environment and transportation walking versus recreational walking. Results Previous reviews and newer studies document consistent positive relations between walking for transportation and density, distance to non-residential destinations, and land use mix; findings for route/network connectivity, parks and open space, and personal safety are more equivocal. Results regarding recreational walking were less clear. Conclusions More recent evidence supports the conclusions of prior reviews, and new studies address some of the limitations of earlier studies. Although prospective studies are needed, evidence on correlates appears sufficient to support policy changes. PMID:18562973

  15. Multichannel Analyzer Built from a Microcomputer.

    ERIC Educational Resources Information Center

    Spencer, C. D.; Mueller, P.

    1979-01-01

    Describes a multichannel analyzer built using eight-bit S-100 bus microcomputer hardware. The output modes are an oscilloscope display, print data, and send data to another computer. Discusses the system's hardware, software, costs, and advantages relative to commercial multichannels. (Author/GA)

  16. Vortex dynamics and scalar transport in the wake of a bluff body driven through a steady recirculating flow

    NASA Astrophysics Data System (ADS)

    Poussou, Stephane B.; Plesniak, Michael W.

    2012-09-01

    The air ventilation system in wide-body aircraft cabins provides passengers with a healthy breathing environment. In recent years, the increase in global air traffic has amplified contamination risks by airborne flu-like diseases and terrorist threats involving the onboard release of noxious materials. In particular, passengers moving through a ventilated cabin may transport infectious pathogens in their wake. This paper presents an experimental investigation of the wake produced by a bluff body driven through a steady recirculating flow. Data were obtained in a water facility using particle image velocimetry and planar laser induced fluorescence. Ventilation attenuated the downward convection of counter-rotating vortices produced near the free-end corners of the body and decoupled the downwash mechanism from forward entrainment, creating stagnant contaminant regions.

  17. Investigation of groundwater recirculation for the removal of RDX from the Pantex Plant perched aquifer

    SciTech Connect

    Woods, A.L.; Barnes, D.L.; Boles, K.M.; Charbeneau, R.J.; Black, S.; Rainwater, K.

    1998-07-01

    The Pantex Plant near Amarillo, Texas, is a US Department of Energy (DOE) facility that has been in operation since 1942. Past and present operations at Pantex include the creation of chemical high explosives components for nuclear weapons and assembly and disassembly of nuclear weapons. The Pantex Plant is underlain by the Ogallala aquifer, which in this area, consists of the main water-bearing unit and a perched water zone. These are separated by a fine-grained zone of low permeability. Multiple contaminant plumes containing high explosive (HE) compounds have been detected in the perched aquifer beneath the plant. The occurrence of these contaminants is the result of past waste disposal practices at the facility. RDX is an HE compound, which has been detected in the groundwater of the perched aquifer at significant concentrations. A pilot-scale, dual-phase extraction treatment system has been installed at one location at the plant, east of Zone 12, to test the effectiveness of such a system on the removal of these contaminants from the subsurface. A tracer test using a conservative tracer, bromide (Br), was conducted at the treatment site in 1996. In addition to the bromide, RDX and water elevations in the aquifer were monitored. Using data from the tracer test and other relevant data from the investigations at Pantex, flow and contaminant transport in the perched aquifer were simulated with groundwater models. The flow was modeled using MODFLOW and the transport of contaminants in the aqueous phase was modeled using MT3D. Modeling the perched aquifer had been conducted to characterize the flow in the perched aquifer; estimate RDX retardation in the perched aquifer; and evaluate the use of groundwater re-circulation to enhance the extraction of RDX from the perched aquifer.

  18. Simultaneous methanogenesis and denitrification of aniline wastewater by using anaerobic-aerobic biofilm system with recirculation.

    PubMed

    Chen, Sheng; Sun, Dezhi; Chung, Jong-Shik

    2009-09-30

    Wastewater containing highly concentrated nitrogenous and aromatic compounds, such as aniline, is difficult to degrade and very toxic to microorganisms, especially to nitrifier. In order to remove both carbon and nitrogen from aniline wastewater, recently two biofilm reactors equipped with anaerobic-aerobic cycle and internal recirculation have demonstrated some potential in treating the wastewater. In such system, ammonification, methanogenesis and denitrification reactions occurred simultaneously in one anaerobic reactor, followed by COD removal and nitrification in the aerobic reactor. The effect of recirculation ratio on COD and nitrogen removal using such reactor arrangement was therefore investigated in the present work. The results showed that recirculation had little impact on the overall COD removal or denitrification activity in the anaerobic reactor at any tested ratio, 96-98% of overall COD removal efficiency was achieved with a final effluent COD value below 200mg/L. But nitrification and TN removal were strongly affected by recirculation. The nitrification rate reached a maximum of 0.48 kg N/(m(3)d) at recirculation ratio of 1 and complete nitrification was achieved at the recirculation ratios over 2. TN removal efficiency increased continuously and a sharp reduction of sludge production in the system was observed with increasing recirculation.

  19. Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

    PubMed

    Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

    2014-01-01

    Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Effects of effluent recirculation in vertical-flow constructed wetland on treatment efficiency of livestock wastewater.

    PubMed

    Lian-sheng, He; Hong-liang, Liu; Bei-dou, Xi; Ying-bo, Zhu

    2006-01-01

    Enhancing the treatment efficiency of livestock wastewater by effluent recirculation is investigated in a pilot-scale vertical-flow constructed wetland. The wetland system is composed of downflow and upflow stages, on which narrow-leaf Phragmites communis and common reed Phragmites typhia are planted, respectively; each stage has a dimension of 4 m(2) (2 m x 2 m). Wastewater from the facultative pond is fed into the system intermittently at a flow rate of 0.4 m(3)/d. Recirculation rates of 0, 25%, 50%0, 100% and 150% are adopted to evaluate the effect of the recirculation rate on pollutants removal. This shows that with effluent recirculation the average removal efficiencies of NH4-N, BOD5 and SS obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%o, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, DO and oxidation-reduction potential (ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R(2) > 0.93) are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by the gradually enhanced nitrification process. When recirculation rate is kept constant at 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.

  1. Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

    SciTech Connect

    Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

    1998-12-31

    The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

  2. Recirculation, stagnation and ventilation: The 2014 legionella episode

    NASA Astrophysics Data System (ADS)

    Russo, Ana; Soares, Pedro M. M.; Gouveia, Célia M.; Cardoso, Rita M.; Trigo, Ricardo M.

    2017-04-01

    Legionella transmission through the atmosphere is unusual, but not unprecedented. A scientific paper published in 2006 reports a surge in Pas-de-Calais, France, in which 86 people have been infected by bacteria released by a cooling tower more than 6 km away [3]. Similarly, in Norway, in 2005, there was another case where contamination spread beyond 10 km, although more concentrated within a radius of 1 km from an industrial unit [2]. An unprecedented large Legionella outbreak occurred in November 2014 nearby Lisbon, Portugal. As of 7 November 2014, 375 individuals become hill and 12 died infected by the Legionella pneumophila bacteria, contracted by inhalation of steam droplets of contaminated water (aerosols). These droplets are so small that can carry the bacteria directly to the lungs, depositing it in the alveoli. One way of studying the propagation of legionella episodes is through the use of aerosol dispersion models. However, such approaches often require detailed 3D high resolution wind data over the region, which isn't often available for long periods. The likely impact of wind on legionella transmission can also be understood based on the analysis of special types of flow conditions such as stagnation, recirculation and ventilation [1, 4]. The Allwine and Whiteman (AW) approach constitutes a straightforward method to assess the assimilative and dispersal capacities of different airsheds [1,4], as it only requires hourly wind components. Thus, it has the advantage of not needing surface and upper air meteorological observations and a previous knowledge of the atmospheric transport and dispersion conditions. The objective of this study is to analyze if the legionella outbreak event which took place in November 2014 had extreme potential recirculation and/or stagnation characteristics. In order to accomplish the proposed objective, the AW approach was applied for a hindcast time-series covering the affected area (1989-2007) and then for an independent

  3. Built-Environment Wind Turbine Roadmap

    SciTech Connect

    Smith, J.; Forsyth, T.; Sinclair, K.; Oteri, F.

    2012-11-01

    Although only a small contributor to total electricity production needs, built-environment wind turbines (BWTs) nonetheless have the potential to influence the public's consideration of renewable energy, and wind energy in particular. Higher population concentrations in urban environments offer greater opportunities for project visibility and an opportunity to acquaint large numbers of people to the advantages of wind projects on a larger scale. However, turbine failures will be equally visible and could have a negative effect on public perception of wind technology. This roadmap provides a framework for achieving the vision set forth by the attendees of the Built-Environment Wind Turbine Workshop on August 11 - 12, 2010, at the U.S. Department of Energy's National Renewable Energy Laboratory. The BWT roadmap outlines the stakeholder actions that could be taken to overcome the barriers identified. The actions are categorized as near-term (0 - 3 years), medium-term (4 - 7 years), and both near- and medium-term (requiring immediate to medium-term effort). To accomplish these actions, a strategic approach was developed that identifies two focus areas: understanding the built-environment wind resource and developing testing and design standards. The authors summarize the expertise and resources required in these areas.

  4. 2. EAST ELEVATION OF IPA FACTORY; TWOSTORY SECTION BUILT IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EAST ELEVATION OF IPA FACTORY; TWO-STORY SECTION BUILT IN 1892 AND PARTIALLY DESTROYED PARAPET SECTION BUILT CA. 1948. BRICK CHIMNEY ALSO BUILT CA. 1948. - Illinois Pure Aluminum Company, 109 Holmes Street, Lemont, Cook County, IL

  5. One Bedroom Units: Floor Plan, South Elevation (As Built), North ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    One Bedroom Units: Floor Plan, South Elevation (As Built), North Elevation (As Built), Section A-A (As Built), Section AA (Existing) - Aluminum City Terrace, East Hill Drive, New Kensington, Westmoreland County, PA

  6. Evidence for baroclinic instability in the Gulf Stream recirculation

    NASA Astrophysics Data System (ADS)

    Hogg, Nelson G.

    Long term current measurements from Polymode Array 2 are analyzed using the technique of empirical orthogonal functions applied in the frequency domain. The region of especially good instrument coverage and clearest decomposition into empirical modes is also in the Gulf Stream recirculation (∼ 36°N 55°W). On theoretical grounds, this is expected to be an area actively unstable to baroclinic disturbances ( GILL, GREEN and SIMMONS, 1974). Both the horizontal and vertical structure of motions with periods ranging from 10 to 120 days are studied. Spectra reveal that kinetic energy is peaked at 30 day periods with a weaker peak at 12 days. The most energetic empirical mode accounts for about 50% of the measured energy although somewhat less than this at higher subinertial frequencies. Consistent with the theoretical calculations of Gill, Green and Simmons it is found that the zonal phase propagation is nearly independent of frequency and averages about 12 cm s -1 toward the west. The 30 and 12 day energy peaks correspond to wavenumbers (wavelengths) of -0.18 km -1 (350 km) and -.033 km -1 (190 km) respectively. These are almost identical to the predicted scales for secondary and primary growth rate maxima for baroclinically unstable disturbances to a zonal current which is horizontally uniform but whose strength decreases exponentially with depth. Energy in these motions increases toward the west at a rate which is statistically indistinguishable from zero but also from the predicted rate. The vertical structure of these motions is also qualitatively similar to the theoretical modes. Phase for velocity decreases with depth, whereas temperature phase increases leading to energy release concentrated in the thermocline near the steering level which is projected to be somewhere above the shallowest observational level (600 m). The 30 day wave is much less depth dependent in amplitude than the 12 day wave and is responsible for the intense deep eddy field observed in

  7. Breadboard Facility

    NASA Technical Reports Server (NTRS)

    1977-01-01

    In the sixties, Chrysler was NASA's prime contractor for the Saturn I and IB test launch vehicles. The company installed and operated at Huntsville what was known as the Saturn I/IB Development Breadboard Facility. "Breadboard," means an array of electrical and electronic equipment for performing a variety of development and test functions. This work gave Chrysler a broad capability in computerized testing to assure quality control in development of solid-state electronic systems. Today that division is manufacturing many products not destined for NASA, most of them being associated with the company's automotive line. A major project is production and quality-control testing of the "lean-burn" engine, one that has a built-in Computer to control emission timing, and allow the engine to run on a leaner mixture of fuel and air. Other environment-related products include vehicle emission analyzers. The newest of the line is an accurate, portable solid state instrument for testing auto exhaust gases. The exhaust analyzers, now being produced for company dealers and for service

  8. The evaluation of oxygen and carbon dioxide transfer associated with airlifts in recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    Airlifts in recirculating aquaculture systems (RAS) provide aeration, degasification, and water circulation. They allow the simplification of systems, and if designed properly, can reduce the capital costs and minimize operation and maintenance associated with alternative pumping systems. In order t...

  9. High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays

    SciTech Connect

    Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

    2007-04-17

    Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

  10. External built residential environment characteristics that affect mental health of adults.

    PubMed

    Ochodo, Charles; Ndetei, D M; Moturi, W N; Otieno, J O

    2014-10-01

    External built residential environment characteristics include aspects of building design such as types of walls, doors and windows, green spaces, density of houses per unit area, and waste disposal facilities. Neighborhoods that are characterized by poor quality external built environment can contribute to psychosocial stress and increase the likelihood of mental health disorders. This study investigated the relationship between characteristics of external built residential environment and mental health disorders in selected residences of Nakuru Municipality, Kenya. External built residential environment characteristics were investigated for 544 residents living in different residential areas that were categorized by their socioeconomic status. Medically validated interview schedules were used to determine mental health of residents in the respective neighborhoods. The relationship between characteristics of the external built residential environment and mental health of residents was determined by multivariable logistic regression analyses and chi-square tests. The results show that walling materials used on buildings, density of dwelling units, state of street lighting, types of doors, states of roofs, and states of windows are some built external residential environment characteristics that affect mental health of adult males and females. Urban residential areas that are characterized by poor quality external built environment substantially expose the population to daily stressors and inconveniences that increase the likelihood of developing mental health disorders.

  11. KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the Japanese Experiment Module (JEM) pressurized module (Kibo or Hope) and the U.S. Node 2, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The JEM pressurized module arrived at KSC on June 4. It is Japan's primary contribution to the Station.

    NASA Image and Video Library

    2003-06-19

    KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the Japanese Experiment Module (JEM) pressurized module (Kibo or Hope) and the U.S. Node 2, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The JEM pressurized module arrived at KSC on June 4. It is Japan's primary contribution to the Station.

  12. KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The pressurized module of the Japanese Experiment Module (JEM), named "Kibo" (Hope), arrived at KSC on June 4. It is Japan's primary contribution to the Station.

    NASA Image and Video Library

    2003-06-19

    KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The pressurized module of the Japanese Experiment Module (JEM), named "Kibo" (Hope), arrived at KSC on June 4. It is Japan's primary contribution to the Station.

  13. KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the U.S. Node 2 and the Japanese Experiment Module (JEM) pressurized module, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The JEM pressurized module, named "Kibo" (Hope), arrived at KSC on June 4. It is Japan's primary contribution to the Station.

    NASA Image and Video Library

    2003-06-19

    KENNEDY SPACE CENTER, FLA. - International Space Station elements being processed for launch on upcoming Space Shuttle flights, including the U.S. Node 2 and the Japanese Experiment Module (JEM) pressurized module, line the walls of the high bay in the Space Station Processing Facility. NASA's Node 2, built by the European Space Agency (ESA) in Italy, arrived at KSC on June 1. It will be the next pressurized module installed on the Station. The JEM pressurized module, named "Kibo" (Hope), arrived at KSC on June 4. It is Japan's primary contribution to the Station.

  14. KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is suspended by cables over the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is suspended by cables over the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  15. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers confirm the Multi-Purpose Logistics Module Donatello is safely in place on a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers confirm the Multi-Purpose Logistics Module Donatello is safely in place on a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  16. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the Multi-Purpose Logistics Module Donatello is slowly lowered toward a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the Multi-Purpose Logistics Module Donatello is slowly lowered toward a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  17. KENNEDY SPACE CENTER, FLA. - This view reveals all three Multi-Purpose Logistics Modules on the floor of the Space Station Processing Facility. This is the first time all three - Leonardo, Raffaello and Donatello -- have been in one location. Donatello has been stored in the Operations and Checkout Building since its arrival at KSC and was brought into the SSPF for routine testing. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-18

    KENNEDY SPACE CENTER, FLA. - This view reveals all three Multi-Purpose Logistics Modules on the floor of the Space Station Processing Facility. This is the first time all three - Leonardo, Raffaello and Donatello -- have been in one location. Donatello has been stored in the Operations and Checkout Building since its arrival at KSC and was brought into the SSPF for routine testing. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  18. KENNEDY SPACE CENTER, FLA. - All three Multi-Purpose Logistics Modules are on the floor of the Space Station Processing Facility. This is the first time the three - Leonardo, Raffaello and Donatello -- have been in one location. Donatello has been stored in the Operations and Checkout Building since its arrival at KSC and was brought into the SSPF for routine testing. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-18

    KENNEDY SPACE CENTER, FLA. - All three Multi-Purpose Logistics Modules are on the floor of the Space Station Processing Facility. This is the first time the three - Leonardo, Raffaello and Donatello -- have been in one location. Donatello has been stored in the Operations and Checkout Building since its arrival at KSC and was brought into the SSPF for routine testing. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  19. KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility secure the Multi-Purpose Logistics Module Raffaello onto a new work stand. Raffaello is the second MPLM built by the Italian Space Agency, serving as a reusable logistics carrier and primary delivery system to resupply and return station cargo requiring a pressurized environment. It has been moved to allow the third MPLM, Donatello, to be brought in for routine testing. Donatello has been stored in the Operations and Checkout Building. This is the first time all three MPLMs are in the SSPF; the other one is the Leonardo. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-10

    KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility secure the Multi-Purpose Logistics Module Raffaello onto a new work stand. Raffaello is the second MPLM built by the Italian Space Agency, serving as a reusable logistics carrier and primary delivery system to resupply and return station cargo requiring a pressurized environment. It has been moved to allow the third MPLM, Donatello, to be brought in for routine testing. Donatello has been stored in the Operations and Checkout Building. This is the first time all three MPLMs are in the SSPF; the other one is the Leonardo. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  20. KENNEDY SPACE CENTER, FLA. - Overhead cables carry the Multi-Purpose Logistics Module Donatello from the payload canister (lower right) to a work stand in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - Overhead cables carry the Multi-Purpose Logistics Module Donatello from the payload canister (lower right) to a work stand in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  1. KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is moved away from the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is moved away from the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  2. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers help the Multi-Purpose Logistics Module Donatello settle onto a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers help the Multi-Purpose Logistics Module Donatello settle onto a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  3. KENNEDY SPACE CENTER, FLA. - Workers on the floor of the Space Station Processing Facility watch as overhead cables carry the Multi-Purpose Logistics Module Donatello to a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-13

    KENNEDY SPACE CENTER, FLA. - Workers on the floor of the Space Station Processing Facility watch as overhead cables carry the Multi-Purpose Logistics Module Donatello to a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  4. KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Raffaello moves away from its stand in the Space Station Processing Facility. Raffaello is the second MPLM built by the Italian Space Agency, serving as a reusable logistics carrier and primary delivery system to resupply and return station cargo requiring a pressurized environment. It is being moved to allow the third MPLM, Donatello, to be brought in for routine testing. Donatello has been stored in the Operations and Checkout Building. This is the first time all three MPLMs are in the SSPF; the other one is the Leonardo. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

    NASA Image and Video Library

    2004-02-10

    KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Raffaello moves away from its stand in the Space Station Processing Facility. Raffaello is the second MPLM built by the Italian Space Agency, serving as a reusable logistics carrier and primary delivery system to resupply and return station cargo requiring a pressurized environment. It is being moved to allow the third MPLM, Donatello, to be brought in for routine testing. Donatello has been stored in the Operations and Checkout Building. This is the first time all three MPLMs are in the SSPF; the other one is the Leonardo. Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.

  5. AMTEC recirculating test cell component testing and operation

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; Sievers, R. K.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Bankston, C. P.

    1989-01-01

    Alkali metal thermoelectric converter operation in a recirculating test cell (RTC), which requires a small electromagnetic pump (EM) and a high-temperature beta-double-prime alumina-solid-electrolyte (BASE)-to-metal seal, is discussed. The design of a pump and an active metal braze seal and the initial operation of a cell using these components are described. The pump delivered 0.25 cu cm/min against a 28-psia head. A braze seal system was selected after shear strength tests of Ta or Nb brazed to BASE by a variety of fillers including TiCuNi, TiNi, and TiNiCr. The TiCuNi filler was chosen for environment cell testing and showed no failure or observable degradation after short-term tests up to 1055 K. The pump and the Nb/TiCuNi/BASE seal were used in a test that demonstrated all the operational functions of the RTC for the first time. An increase in the radiation reduction factor at constant input power was observed, indicating that the condenser was being wet by sodium resulting in an increased reflectivity.

  6. Subsets of blood, spleen and recirculating lymphocytes in man.

    PubMed Central

    Reinecke, G; Pabst, R

    1983-01-01

    Lymphocyte subpopulations were characterized in human blood and spleens. In addition the spleens were perfused by a closed extracorporeal perfusion system under almost physiological conditions. Lymphocytes released from the spleen during perfusion were taken to be representative of recirculating lymphocytes. B lymphocytes were classified by their surface immunoglobulin, T lymphocytes and T lymphocyte subsets by cytochemistry, sheep red blood cell rosette formation and in some experiments by monoclonal antibodies. In the blood 71 +/- 4.3% of the lymphocytes were rosette forming cells and 23.3 +/- 3.8% B lymphocytes. In the spleen 49.8 +/- 3.6% were T and 53.3 +/- 2.1% were B lymphocytes. In three spleens the mean number of OKT3+ lymphocytes were 27.6 +/- 7.0% OKT4+ 8.6 +/- 1.4% and OKT8+ 13.7 +/- 2.2%. The ratio of T helper to T suppressor lymphocytes was 0.67 for the spleen and 1.7 for the blood. The lymphocytes released from the perfused spleen showed a similar distribution pattern of surface markers to that of the splenic subpopulations. Images Fig. 1 PMID:6225579

  7. The skin, a novel niche for recirculating B cells1

    PubMed Central

    Geherin, Skye A.; Fintushel, Sarah R.; Lee, Michael H.; Wilson, R. Paul; Patel, Reema T.; Alt, Carsten; Young, Alan J.; Hay, John B.; Debes, Gudrun F.

    2012-01-01

    B cells infiltrate the skin in many chronic inflammatory diseases caused by autoimmunity or infection. Despite potential contribution to disease, skin-associated B cells remain poorly characterized. Using an ovine model of granulomatous skin inflammation, we demonstrate that B cells increase in the skin and skin-draining afferent lymph during inflammation. Surprisingly, skin B cells are a heterogeneous population that is distinct from lymph node B cells, with more large lymphocytes as well as B-1-like B cells that co-express high levels IgM and CD11b. Skin B cells have increased MHCII, CD1, and CD80/86 expression compared with lymph node B cells, suggesting that they are well-suited for T cell activation at the site of inflammation. Furthermore, we show that skin accumulation of B cells and antibody-secreting cells during inflammation increases local antibody titers, which could augment host defense and autoimmunity. While skin B cells express typical skin homing receptors such as E-selectin ligand and alpha-4 and beta-1 integrins, they are unresponsive to ligands for chemokine receptors associated with T cell homing into skin. Instead, skin B cells migrate toward the cutaneously expressed CCR6 ligand CCL20. Our data support a model in which B cells use CCR6-CCL20 to recirculate through the skin, fulfilling a novel role in skin immunity and inflammation. PMID:22561151

  8. In situ treatment of VOCs by recirculation technologies

    SciTech Connect

    Siegrist, R.L.; Webb, O.F.; Ally, M.R.; Sanford, W.E.; Kearl, P.M.; Zutman, J.L.

    1993-06-01

    The project described herein was conducted by Oak Ridge National Laboratory (ORNL) to identify processes and technologies developed in Germany that appeared to have near-term potential for enhancing the cleanup of volatile organic compound (VOC) contaminated soil and groundwater at DOE sites. Members of the ORNL research team identified and evaluated selected German technologies developed at or in association with the University of Karlsruhe (UoK) for in situ treatment of VOC contaminated soils and groundwater. Project activities included contacts with researchers within three departments of the UoK (i.e., Applied Geology, Hydromechanics, and Soil and Foundation Engineering) during fall 1991 and subsequent visits to UoK and private industry collaborators during February 1992. Subsequent analyses consisted of engineering computations, groundwater flow modeling, and treatment process modeling. As a result of these project efforts, two processes were identified as having near-term potential for DOE: (1) the vacuum vaporizer well/groundwater recirculation well and (2) the porous pipe/horizontal well. This document was prepared to summarize the methods and results of the assessment activities completed during the initial year of the project. The project is still ongoing, so not all facets of the effort are completely described in this document. Recommendations for laboratory and field experiments are provided.

  9. Aircraft Recirculation Filter for Air-Quality and Incident Assessment

    PubMed Central

    Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

    2015-01-01

    The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters. PMID:25641977

  10. Recirculating Linac Acceleration - End-to-End Simulation

    SciTech Connect

    Alex Bogacz

    2010-03-01

    A conceptual design of a high-pass-number Recirculating Linear Accelerator (RLA) for muons is presented. The scheme involves three superconducting linacs (201 MHz): a single pass linear Pre-accelerator followed by a pair multi-pass (4.5-pass) 'Dogbone' RLAs. Acceleration starts after ionization cooling at 220 MeV/c and proceeds to 12.6 GeV. The Pre-accelerator captures a large muon phase space and accelerates muons to relativistic energies, while adiabatically decreasing the phase-space volume, so that effective acceleration in the RLA is possible. The RLA further compresses and shapes up the longitudinal and transverse phase-spaces, while increasing the energy. Appropriate choice of multi-pass linac optics based on FODO focusing assures large number of passes in the RLA. The proposed 'Dogbone' configuration facilitates simultaneous acceleration of both mu± species through the requirement of mirror symmetric optics of the return 'droplet' arcs. Finally, presented end-to-end simulation validates the efficiency and acceptance of the accelerator system.

  11. Efficiency of an AMTEC recirculating test cell, experiments and projections

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.

    1992-01-01

    The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of heat to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15 to 35 percent thermal to electric conversion efficiencies, and one experiment has demonstrated 19 percent efficiency for a short period of time. Recent experiments in a recirculating test cell (RTC) have demonstrated sustained conversion efficiencies as high as 10.2 percent early in cell life and 9.7 percent after maturity. Extensive thermal and electrochemical analysis of the cell during several experiments demonstrated that the efficiency could be improved in two ways. First, the electrode performance could be improved. The electrode for these tests operated at about one third the power density of state of the art electrodes. The low power density was caused by a combination of high series resistance and high mass flow resistance. Reducing these resistances could improve the efficiency to greater than 10 percent. Second, the cell thermal performance could be improved. Efficiencies greater than 14 percent could be realized through reducing the radiative thermal loss. Further improvements to the efficiency range predicted by systems studies can be accomplished through the development and use of an advanced condenser with improved reflectivity, close to that of a smooth sodium film, and the series connecting of individual cells to further reduce thermal losses.

  12. [Molecular Adsorbent Recirculating System in liver function replacement therapy].

    PubMed

    Marangoni, R

    2005-01-01

    The molecular adsorbent recirculating system (MARS) method removes from the blood catabolites either free in the plasma water such as uremic toxins and ammonia, taking advantage of dialysis or free albumin bound ones, like hepatic toxins, transferring them from the albumin in the blood to the albumin circulating in a closed loop where toxins are removed by adsorbtion on resins (charcoal and ion exchange resin). The efficacy of the method in removing the hepatic toxins either in the acute or in the acute on chronic liver failure is demonstrated in numerous studies. Based on these findings, 10 patients affected by acute on chronic liver failure were treated. The results demonstrated that the method, powerfully removing ammonia, bilirubin and bile acids (taken as method efficacy markers), reduced the blood concentrations of these molecules remarkably; allowing the elimination of the refractory pruritus (due to the lowering of plasma bile acid levels), an almost constant symptom in chronic liver diseases, especially with cholestasis, and improves other parameters (cholinesterase, alkaline phosphatase and prothrombin activity). These results agree with those reported in the literature concerning the efficacy of MARS in the replacement of the liver detoxifying function.

  13. Efficiency of an AMTEC recirculating test cell, experiments and projections

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.

    1992-01-01

    The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of heat to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15 to 35 percent thermal to electric conversion efficiencies, and one experiment has demonstrated 19 percent efficiency for a short period of time. Recent experiments in a recirculating test cell (RTC) have demonstrated sustained conversion efficiencies as high as 10.2 percent early in cell life and 9.7 percent after maturity. Extensive thermal and electrochemical analysis of the cell during several experiments demonstrated that the efficiency could be improved in two ways. First, the electrode performance could be improved. The electrode for these tests operated at about one third the power density of state of the art electrodes. The low power density was caused by a combination of high series resistance and high mass flow resistance. Reducing these resistances could improve the efficiency to greater than 10 percent. Second, the cell thermal performance could be improved. Efficiencies greater than 14 percent could be realized through reducing the radiative thermal loss. Further improvements to the efficiency range predicted by systems studies can be accomplished through the development and use of an advanced condenser with improved reflectivity, close to that of a smooth sodium film, and the series connecting of individual cells to further reduce thermal losses.

  14. Role of enterohepatic recirculation in drug disposition: cooperation and complications.

    PubMed

    Malik, Mohd Yaseen; Jaiswal, Swati; Sharma, Abhisheak; Shukla, Mahendra; Lal, Jawahar

    2016-05-01

    Enterohepatic recirculation (EHC) concerns many physiological processes and notably affects pharmacokinetic parameters such as plasma half-life and AUC as well as estimates of bioavailability of drugs. Also, EHC plays a detrimental role as the compounds/drugs are allowed to recycle. An in-depth comprehension of this phenomenon and its consequences on the pharmacological effects of affected drugs is important and decisive in the design and development of new candidate drugs. EHC of a compound/drug occurs by biliary excretion and intestinal reabsorption, sometimes with hepatic conjugation and intestinal deconjugation. EHC leads to prolonged elimination half-life of the drugs, altered pharmacokinetics and pharmacodynamics. Study of the EHC of any drug is complicated due to unavailability of the apposite model, sophisticated procedures and ethical concerns. Different in vitro and in vivo methods for studies in experimental animals and humans have been devised, each having its own merits and demerits. Involvement of the different transporters in biliary excretion, intra- and inter-species, pathological and biochemical variabilities obscure the study of the phenomenon. Modeling of drugs undergoing EHC has always been intricate and exigent models have been exploited to interpret the pharmacokinetic profiles of drugs witnessing multiple peaks due to EHC. Here, we critically appraise the mechanisms of bile formation, factors affecting biliary drug elimination, methods to estimate biliary excretion of drugs, EHC, multiple peak phenomenon and its modeling.

  15. Aircraft Recirculation Filter for Air-Quality and Incident Assessment.

    PubMed

    Eckels, Steven J; Jones, Byron; Mann, Garrett; Mohan, Krishnan R; Weisel, Clifford P

    The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters.

  16. Efficiency of an AMTEC recirculating test cell, experiments and projections

    SciTech Connect

    Underwood, M.L.; O`Connor, D.; Williams, R.M.; Jeffries-Nakamura, B.; Ryan, M.A.

    1992-05-01

    The alkali metal thermal to electric converter (AMTEC) is an electrochemical device for the direct conversion of heat to electrical energy with efficiencies potentially near Carnot. The future usefulness of AMTEC for space power conversion depends on the efficiency of the devices. Systems studies have projected from 15% to 35% thermal to electric conversion efficiencies, and one experiment has demonstrated 19% efficiency for a short period of time. Recent experiments in a recirculating test cell (RTC) have demonstrated sustained conversion efficiencies as high as 10.2% early in cell life and 9.7% after maturity. Extensive thermal and electrochemical analysis of the cell during several experiments demonstrated that the efficiency could be improved in two ways. First, the electrode performance could be improved. The electrode for these tests operated at about one third the power density of state of the art electrodes. The low power density was caused by a combination of high series resistance and high mass flow resistance. Reducing these resistances could improve the efficiency to greater than 10%. Second, the cell thermal performance could be improved. Efficiencies greater than 14% could be realized through reducing the radiative thermal loss. Further improvements to the efficiency range predicted by systems studies can be accomplished through the development and use of an advanced condenser with improved reflectivity, close to that of a smooth sodium film, and the series connecting of individual cells to further reduce thermal losses.

  17. Reduction of Beam Breakup Growth by Cavity Cross-Couplings in Recirculating Accelerators

    DTIC Science & Technology

    1990-06-29

    recirculating accelerators with Perry Wilson, Pisin Chen, Sam Penner and Roger Miller. Both Denis Colombant and David Chernin are supported by DARPA and monitored...Switzerland (1984), Chapter 9. The earliest publication on BBU in recirculating accelerators is perhaps the one by P. B. Wilson and C. S. Nunan , IEEE...Smith Mr. Gerald J. Peters (G-256) Dr. David Sutter Air Force Weapons Laboratory Kirtland Air Force Base Directed Technologies, Inc. Albuquerque, NM 87117

  18. A Multiprocessor Emulation Facility.

    DTIC Science & Technology

    1983-09-01

    make the facility usable. We considered three classes of machines: 1. Commercially available Motorola M68000 -based single board computers. 2. Our own...One of the most interesting multiprocessor systems built to date is the BBN Butterfly machine [17]. It currently consists of 10 M68000 boards connected...by a circuit switched network of butterfly (ie., FFT or shuffle exchange) topology. The machine can be extended to several hundred M68000s because the

  19. Anolyte recirculation effects in buffered and unbuffered single-chamber air-cathode microbial fuel cells.

    PubMed

    Zhang, Liang; Zhu, Xun; Kashima, Hiroyuki; Li, Jun; Ye, Ding-ding; Liao, Qiang; Regan, John M

    2015-03-01

    Two identical microbial fuel cells (MFCs) with a floating air-cathode were operated under either buffered (MFC-B) or bufferless (MFC-BL) conditions to investigate anolyte recirculation effects on enhancing proton transfer. With an external resistance of 50 Ω and recirculation rate of 1.0 ml/min, MFC-BL had a 27% lower voltage (9.7% lower maximal power density) but a 64% higher Coulombic efficiency (CE) than MFC-B. MFC-B had a decreased voltage output, batch time, and CE with increasing recirculation rate resulting from more oxygen transfer into the anode. However, increasing the recirculation rate within a low range significantly enhanced proton transfer in MFC-BL, resulting in a higher voltage output, a longer batch time, and a higher CE. A further increase in recirculation rate decreased the batch time and CE of MFC-BL due to excess oxygen transfer into anode outweighing the proton-transfer benefits. The unbuffered MFC had an optimal recirculation rate of 0.35 ml/min. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Atmospheric stagnation, recirculation and ventilation potential of several sites in Argentina

    NASA Astrophysics Data System (ADS)

    Venegas, L. E.; Mazzeo, N. A.

    Conditions for stagnation, recirculation and ventilation potential of the atmosphere were studied in five argentine cities: Resistencia, Córdoba, Buenos Aires, Mar del Plata and Comodoro Rivadavia, located in different regions of the country. Wind run and recirculation factors were calculated for a 24-h transport time using 2 years of hourly surface measurements of wind speed and direction. The largest stagnation frequency (45% of the time) was observed in Resistencia, located in the northeastern part of the country, in an area where winds are weak. The least frequency of stagnations (2%) was observed in Comodoro Rivadavia, in the southern region of the country, a region dominated by strong westerly winds. Comodoro Rivadavia and Córdoba registered the largest frequency of recirculations. Comodoro Rivadavia exposed to sea-land breezes and Córdoba, located on a complex terrain area and exposed to local circulations, experienced recirculation events during 10% of the time. Good atmospheric ventilation occurs when a high value of wind run and a low value of the recirculation factor are observed and it can be associated with the atmosphere's capacity to replace polluted air with clean air. Ventilation events occurred 58% of the time at Comodoro Rivadavia, 52% at Mar del Plata, 40% at Buenos Aires, 35% at Córdoba and 18% at Resistencia. In general, stagnation was more frequently observed during autumn and winter, recirculation during spring and summer and good ventilation conditions occurred during spring.

  1. Nitrogen oxides emissions from the MILD combustion with the conditions of recirculation gas.

    PubMed

    Park, Min; Shim, Sung Hoon; Jeong, Sang Hyun; Oh, Kwang-Joong; Lee, Sang-Sup

    2017-04-01

    The nitrogen oxides (NOx) reduction technology by combustion modification which has economic benefits as a method of controlling NOx emitted in the combustion process, has recently been receiving a lot of attention. Especially, the moderate or intense low oxygen dilution (MILD) combustion which applied high temperature flue gas recirculation has been confirmed for its effectiveness with regard to solid fuel as well. MILD combustion is affected by the flue gas recirculation ratio and the composition of recirculation gas, so its NOx reduction efficiency is determined by them. In order to investigate the influence of factors which determine the reduction efficiency of NOx in MILD coal combustion, this study changed the flow rate and concentration of nitrogen (N2), carbon dioxide (CO2) and steam (H2O) which simulate the recirculation gas during the MILD coal combustion using our lab-scale drop tube furnace and performed the combustion experiment. As a result, its influence by the composition of recirculation gas was insignificant and it was shown that flue gas recirculation ratio influences the change of NOx concentration greatly.

  2. Experimental and numerical study of a turbulent recirculation zone with combustion

    NASA Astrophysics Data System (ADS)

    Moreau, P.; Labbe, J.; Dupoirieux, F.; Borghi, R.

    An experimental and computational study has been carried out on recirculation zones as related to afterburner devices for turbojet engines. The following conclusions can be pointed out: (1) the recirculation zone behind a bluff body in a confined flow is shortened when the combustion is stabilized by this bluff body; (2) the shortening is well reproduced by the calculation results and probably the effect is related to the increase of massic volume of combusting gases behind the recirculation zone and not to the turbulence modification; (3) the turbulence within the recirculation zone is clearly modified when combustion occurs with the anisotropy of the turbulence enhanced, the Reynolds stress increased, and the location of the maximum of turbulence kinetic energy displaced; and (4) the length of the recirculation region, and the mean velocity profiles can be computed with a good agreement with a constant eddy viscosity model (without and with combustion). The classical k-epsilon model leads to a bader agreement; qualitatively, the modification of the turbulence within the recirculation zone when the combustion is operated does not appear well reproduced by the classical k-epsilon model.

  3. Cell buffer with built-in test

    NASA Technical Reports Server (NTRS)

    Ott, William E. (Inventor)

    2004-01-01

    A cell buffer with built-in testing mechanism is provided. The cell buffer provides the ability to measure voltage provided by a power cell. The testing mechanism provides the ability to test whether the cell buffer is functioning properly and thus providing an accurate voltage measurement. The testing mechanism includes a test signal-provider to provide a test signal to the cell buffer. During normal operation, the test signal is disabled and the cell buffer operates normally. During testing, the test signal is enabled and changes the output of the cell buffer in a defined way. The change in the cell buffer output can then be monitored to determine if the cell buffer is functioning correctly. Specifically, if the voltage output of the cell buffer changes in a way that corresponds to the provided test signal, then the functioning of the cell buffer is confirmed. If the voltage output of the cell buffer does not change correctly, then the cell buffer is known not to be operating correctly. Thus, the built in testing mechanism provides the ability to quickly and accurately determine if the cell buffer is operating correctly. Furthermore, the testing mechanism provides this functionality without requiring excessive device size and complexity.

  4. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  5. Concentrated solar power in the built environment

    NASA Astrophysics Data System (ADS)

    Montenon, Alaric C.; Fylaktos, Nestor; Montagnino, Fabio; Paredes, Filippo; Papanicolas, Costas N.

    2017-06-01

    Solar concentration systems are usually deployed in large open spaces for electricity generation; they are rarely used to address the pressing energy needs of the built environment sector. Fresnel technology offers interesting and challenging CSP energy pathways suitable for the built environment, due to its relatively light weight (<30 kg.m-2) and low windage. The Cyprus Institute (CyI) and Consorzio ARCA are cooperating in such a research program; we report here the construction and integration of a 71kW Fresnel CSP system into the HVAC (Heating, Ventilation, and Air Conditioning) system of a recently constructed office & laboratory building, the Novel Technologies Laboratory (NTL). The multi-generative system will support cooling, heating and hot water production feeding the system of the NTL building, as a demonstration project, part of the STS-MED program (Small Scale Thermal Solar District Units for Mediterranean Communities) financed by the European Commission under the European Neighbourhood and Partnership Instrument (ENPI), CBCMED program.

  6. Development and design of a fluidized bed/upflow sand filter configuration for use in recirculating aquaculture systems

    SciTech Connect

    Burden, D.G.

    1988-01-01

    A fluidized bed/upflow sand filter configuration, was developed and designed for utilization in recirculating aquaculture system, specifically the soft-shell crab and soft-shell crawfish industries. These filters were selected and designed because of their ability to withstand clogging and still maintain high levels of water quality for aquaculture production. The effectiveness of sand grain size was used to evaluate fluidized bed filter performance with filter loadings ranging from 16 to 1285 pounds of crawfish per cubic foot of filter sand. A coarse sand grain size was recommended as a filter media because of it's ability to shear excessive biofilm growth from the and, thus prohibiting clogging from occurring within the filter bed. The fluidized bed/upflow sand filter combination was evaluated in terms of nitrification and oxygen consumption when used with a recirculating crab shedding system. The filter combination's carrying capacity (700 crabs per cubic foot of sand media) exceeded that observed with the submerged rock filter by more than 20 times and was largely explained by the filter's solids removal ability which significantly reduced the filter's oxygen loading rate (OLR). Nitrification rates with the filter combination were extremely high as total ammonia and nitrite levels remained below 1.0 mg-N/l. Verification of a volumetric loading criteria (150 pounds per cubic foot) for this filter combination was further established with performance data obtained from a commercial soft-shell crawfish facility. Water quality monitoring results indicated that the filters maintained total ammonia and nitrite levels below 1.0 mg-N/l under typical operating conditions. Shock loading, pH control, and over-feeding, rather than filter capacity, dominated water quality fluctuations, thereby indicating that the loading criteria was sufficient for commercial operation.

  7. Next Generation Pressurized Oxy-Coal Combustion: High Efficiency and No Flue Gas Recirculation

    SciTech Connect

    Rue, David

    2013-09-30

    The Gas Technology Institute (GTI) has developed a pressurized oxy-coal fired molten bed boiler (MBB) concept, in which coal and oxygen are fired directly into a bed of molten coal slag through burners located on the bottom of the boiler and fired upward. Circulation of heat by the molten slag eliminates the need for a flue gas recirculation loop and provides excellent heat transfer to steam tubes in the boiler walls. Advantages of the MBB technology over other boilers include higher efficiency (from eliminating flue gas recirculation), a smaller and less expensive boiler, modular design leading to direct scalability, decreased fines carryover and handling costs, smaller exhaust duct size, and smaller emissions control equipment sizes. The objective of this project was to conduct techno-economic analyses and an engineering design of the MBB project and to support this work with thermodynamic analyses and oxy-coal burner testing. Techno-economic analyses of GTI’s pressurized oxy-coal fired MBB technology found that the overall plant with compressed CO2 has an efficiency of 31.6%. This is a significant increase over calculated 29.2% efficiency of first generation oxy-coal plants. Cost of electricity (COE) for the pressurized MBB supercritical steam power plant with CO2 capture and compression was calculated to be 134% of the COE for an air-coal supercritical steam power plant with no CO2 capture. This compares positively with a calculated COE for first generation oxy-coal supercritical steam power plants with CO2 capture and compression of 164%. The COE for the MBB power plant is found to meet the U.S. Department of Energy (DOE) target of 135%, before any plant optimization. The MBB power plant was also determined to be simpler than other oxy-coal power plants with a 17% lower capital cost. No other known combustion technology can produce higher efficiencies or lower COE when CO2 capture and compression are included. A thermodynamic enthalpy and exergy analysis

  8. Early molecular adsorbents recirculating system treatment of Amanita mushroom poisoning.

    PubMed

    Kantola, Taru; Kantola, Teemu; Koivusalo, Anna-Maria; Höckerstedt, Krister; Isoniemi, Helena

    2009-10-01

    Acute poisoning due to ingestion of hepatotoxic Amanita sp. mushrooms can result in a spectrum of symptoms, from mild gastrointestinal discomfort to life-threatening acute liver failure. With conventional treatment, Amanita phalloides mushroom poisoning carries a substantial risk of mortality and many patients require liver transplantation. The molecular adsorbent recirculating system (MARS) is an artificial liver support system that can partly compensate for the detoxifying function of the liver by removing albumin-bound and water-soluble toxins from blood. This treatment has been used in acute liver failure to enable native liver recovery and as a bridging treatment to liver transplantation. The aim of the study is to evaluate the outcome of 10 patients with Amanita mushroom poisoning who were treated with MARS. The study was a retrospectively analyzed case series. Ten adult patients with accidental Amanita poisoning of varying severity were treated in a liver disease specialized intensive care unit from 2001 to 2007. All patients received MARS treatment and standard medical therapy for mushroom poisoning. The demographic, laboratory, and clinical data from each patient were recorded upon admission. The one-year survival and need for liver transplantation were documented. The median times from mushroom ingestion to first-aid at a local hospital and to MARS treatment were 18 h (range 14-36 h) and 48 h (range 26-78 h), respectively. All 10 patients survived longer than one year. One patient underwent a successful liver transplantation. No serious adverse side-effects were observed with the MARS treatment. In conclusion, MARS treatment seems to offer a safe and effective treatment option in Amanita mushroom poisoning.

  9. Closed recirculating system for shrimp-mollusk polyculture

    NASA Astrophysics Data System (ADS)

    Wu, Xiongfei; Zhao, Zhidong; Li, Deshang; Chang, Kangmei; Tong, Zhuanshang; Si, Liegang; Xu, Kaichong; Ge, Bailin

    2005-12-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducting the probiotic products timely into the shrimp ponds; adopting a “pen-closing” method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965 kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  10. Photobacterium aquae sp. nov., isolated from a recirculating mariculture system.

    PubMed

    Liu, Ying; Liu, Liang-Zi; Song, Lei; Zhou, Yu-Guang; Qi, Fang-Jun; Liu, Zhi-Pei

    2014-02-01

    A Gram-staining-negative, heterotrophic, facultatively anaerobic bacterium, designated AE6(T), was isolated from a grouper (Epinephelus malabaricas) culture tank in a recirculating mariculture system located in Tianjin, China. Strain AE6(T) was able to grow at 15-40 °C (optimum, 30-35 °C), at pH 5.5-10.0 (optimum, pH 7.0-7.5) and in the presence of 0.5-7% (w/v) NaCl (optimum, 2-3%). It contained Q-8 as the predominant respiratory quinone, phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) as the major polar lipids and C(16 : 1)ω7c/C(16 : 1)ω6c (40.4%), C(18 : 1)ω7c (15.5%) and C(16 : 0) (13.5%) as the predominant cellular fatty acids. The genomic DNA G+C content was 47.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain AE6(T) belonged to the genus Photobacterium (94.2-96.8% of 16S rRNA gene sequence similarity) and formed a distinct phylogenetic lineage within the genus and exhibited the highest sequence similarity to Photobacterium aphoticum CECT 7614(T) (96.8%). Multilocus sequence analysis (MLSA) using four loci (gyrB, rpoA, pyrH and recA) also revealed that strain AE6(T) was phylogenetically related to the genus Photobacterium. Based on the phylogenetic, chemotaxonomic and phenotypic evidence, strain AE6(T) is considered to represent a novel species of the genus Photobacterium, for which the name Photobacterium aquae sp. nov. is proposed. The type strain is AE6(T) ( = CGMCC 1.12159(T) = JCM 18480(T)).

  11. A Student-Built Scanning Tunneling Microscope

    NASA Astrophysics Data System (ADS)

    Ekkens, Tom

    2015-12-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself. I wanted to give my students a deeper appreciation for the physics by having them build a simple scanning tunneling microscope. Initially, 15 hours of an upper-division laboratory class were devoted to building and operating the STM. As the build process was refined, the time commitment for this project has shrunk to nine hours. Using the method described in this paper, the project is now simple enough that it can be built and operated by students in the introductory class.

  12. The Large Built Water Clock Of Amphiaraeion.

    NASA Astrophysics Data System (ADS)

    Theodossiou, E.; Katsiotis, M.; Manimanis, V. N.; Mantarakis, P.

    A very well preserved ancient water clock was discovered during excavations at the Amphiaraeion, in Oropos, Greece. The Amphiaraeion, a famous religious and oracle center of the deified healer Amphiaraus, was active from the pre-classic period until the replacement of the ancient religion by Christianity in the 5th Century A.D.. The foretelling was supposedly done through dreams sent by the god to the believers sleeping in a special gallery. In these dreams the god suggesting to them the therapy for their illness or the solution to their problems. The patients, then threw coins into a spring of the sanctuary. In such a place, the measurement of time was a necessity. Therefore, time was kept with both a conical sundial and a water clock in the form of a fountain. According to archeologists, the large built structure that measured the time for the sanctuary dates from the 4th Century B.C.

  13. Mineral and organic compounds in leachate from landfill with concentrate recirculation.

    PubMed

    Talalaj, Izabela Anna

    2015-02-01

    The effect of a reverse osmosis concentrate recirculation on the mineral and organic compounds in a landfill leachate was investigated. Investigated was the quality of a leachate from two landfills operated for different periods (a 20-year-old Cell A and a 1-year-old Cell B), where the concentrate was recirculated. Examined were general parameters (conductivity, pH), organic compounds (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic nitrogen, BOD/COD), and inorganic compounds (nitrogen ammonia, sulfite, sulfate, cyanide, boron, chloride, ferrous, zinc, chrome, copper). The findings from the first year of investigation showed that over the initial period of recirculation, the concentration of organic compounds (BOD, COD) increased, but after 6 months their values stabilized. It indicates that the concentrate recirculation accelerated organic decomposition, especially in the new landfill Cell. The analysis of inorganic parameters showed that recirculation landfills produce a leachate with a higher concentration of N-NH4, and Cl(-). In case of the old landfill Cell, an increase in B and Fe was also noticeable. These compounds are cyclically washed out from a waste dump and require an additional pretreatment in order to exclude them from recirculation cycle. The increased concentration of Cu, Zn, and Fe was noticed during the initial months of recirculation and in the season of intense atmospheric precipitation in the leachate from both Cells. Higher values of electro conductivity, Cl(-), N-NH4 (+), B, and Fe in the leachate from the old field indicate that the attenuation capacity of this landfill is close to exhaustion.

  14. Assessing the built environment using omnidirectional imagery.

    PubMed

    Wilson, Jeffrey S; Kelly, Cheryl M; Schootman, Mario; Baker, Elizabeth A; Banerjee, Aniruddha; Clennin, Morgan; Miller, Douglas K

    2012-02-01

    Observational audits commonly are used in public health research to collect data on built environment characteristics that affect health-related behaviors and outcomes, including physical activity and weight status. However, implementing in-person field audits can be expensive if observations are needed over large or geographically dispersed areas or at multiple points in time. A reliable and more efficient method for observational audits could facilitate extendibility (i.e., expanded geographic and temporal scope) and lead to more standardized assessment that strengthens the ability to compare results across different regions and studies. The purpose of the current study was to evaluate the degree of agreement between field audits and audits derived from interpretation of three types of omnidirectional imagery. Street segments from St. Louis MO and Indianapolis IN were stratified geographically to ensure representation of neighborhoods with different socioeconomic characteristics in both cities. Audits were conducted in 2008 and 2009 using four methods: field audits, and interpretation of archived imagery, new imagery, and Google Street View™ imagery. Agreement between field audits and image-based audits was assessed using observed agreement and the prevalence-adjusted bias-adjusted kappa statistic (PABAK). Data analysis was conducted in 2010. When measuring the agreement between field audits and audits from the different sources of imagery, the mean PABAK statistic for all items on the instrument was 0.78 (archived); 0.80 (new); and 0.81 (Street View imagery), indicating substantial to nearly perfect agreement among methods. It was determined that image-based audits represent a reliable method that can be used in place of field audits to measure several key characteristics of the built environment important to public health research. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Photocatalytic oxide films in the built environment

    NASA Astrophysics Data System (ADS)

    Österlund, Lars; Topalian, Zareh

    2014-11-01

    The possibility to increase human comfort in buildings is a powerful driving force for the introduction of new technology. Among other things our sense of comfort depends on air quality, temperature, lighting level, and the possibility of having visual contact between indoors and outdoors. Indeed there is an intimate connection between energy, comfort, and health issues in the built environment, leading to a need for intelligent building materials and green architecture. Photocatalytic materials can be applied as coatings, filters, and be embedded in building materials to provide self-cleaning, antibacterial, air cleaning, deodorizing, and water cleaning functions utilizing either solar light or artificial illumination sources - either already present in buildings, or by purposefully designed luminaries. Huge improvements in indoor comfort can thus be made, and also alleviate negative health effects associated with buildings, such as the sick-house syndrome. At the same time huge cost savings can be made by reducing maintenance costs. Photocatalytic oxides can be chemically modified by changing their acid-base surface properties, which can be used to overcome deactivation problems commonly encountered for TiO2 in air cleaning applications. In addition, the wetting properties of oxides can be tailored by surface chemical modifications and thus be made e.g. oleophobic and water repellent. Here we show results of surface acid modified TiO2 coatings on various substrates by means of photo-fixation of surface sulfate species by a method invented in our group. In particular, we show that such surface treatments of photocatalytic concrete made by mixing TiO2 nanoparticles in reactive concrete powders result in concrete surfaces with beneficial self-cleaning properties. We propose that such approaches are feasible for a number of applications in the built environment, including glass, tiles, sheet metals, plastics, etc.

  16. Quench performance of Fermilab/General Dynamics built full length SSC collider dipole magnets

    SciTech Connect

    Strait, J.; Orris, D.; Mazur, P.O.; Bleadon, M.; Bossert, R.; Carson, J.; Delchamps, S.W.; Gourlay, S.; Hanft, R.; Koska, W.; Kuchnir, M.; Lamm, M.J.; Ozelis, J.; Wake, M.; Devred, A.; DiMarco, J.; Kuzminski, J.; Nah, W.; Ogitsu, T.; Puglisi, M.; Tompkins, J.C.; Yu, Y.; Zhao, Y.; Zheng, H.

    1992-04-01

    In this paper we present results of quench testing of full length SSC dipole magnets at Fermilab. The data are from the first six of a series of thirteen 15 m long, 50 mm aperture SSC dipole magnets which are being built and tested at Fermilab. These magnets were designed jointly by Fermilab, Brookhaven Laboratory, Lawrence Berkeley Laboratory and the SSC laboratory. Among the major goals for this series of magnets are to transfer magnet production technology to the lead vendor for the Collider Dipole Magnet, the General Dynamics Corporation, and to demonstrate industrial production by the vendor. The first magnet in the series, DCA311, was built by Fermilab technicians to establish assembly procedures. The second magnet, DCA312, was the ``technology transfer magnet`` and was built jointly by Fermilab and General Dynamics technicians. The next seven, DCA313- 319 are being built by General Dynamics personnel using Fermilab facilities and procedures. However, Fermilab personnel still operate the major tooling, provide the welders, perform assembly of items that would not be part of production magnets (e.g. voltage taps), and oversee the QA program. Five of these 7 GD-built magnets will be used in the Accelerator Systems String Test (ASST) to be carried out in Dallas later this year. The last four magnets, DCA320-323, are being built by Fermilab alone.

  17. Quench performance of Fermilab/General Dynamics built full length SSC collider dipole magnets

    SciTech Connect

    Strait, J.; Orris, D.; Mazur, P.O.; Bleadon, M.; Bossert, R.; Carson, J.; Delchamps, S.W.; Gourlay, S.; Hanft, R.; Koska, W.; Kuchnir, M.; Lamm, M.J.; Ozelis, J.; Wake, M. ); Devred, A.; DiMarco, J.; Kuzminski, J.; Nah, W.; Ogitsu, T.; Puglisi, M.; Tompkins, J.C.; Yu, Y.; Zhao, Y.; Zheng, H. )

    1992-04-01

    In this paper we present results of quench testing of full length SSC dipole magnets at Fermilab. The data are from the first six of a series of thirteen 15 m long, 50 mm aperture SSC dipole magnets which are being built and tested at Fermilab. These magnets were designed jointly by Fermilab, Brookhaven Laboratory, Lawrence Berkeley Laboratory and the SSC laboratory. Among the major goals for this series of magnets are to transfer magnet production technology to the lead vendor for the Collider Dipole Magnet, the General Dynamics Corporation, and to demonstrate industrial production by the vendor. The first magnet in the series, DCA311, was built by Fermilab technicians to establish assembly procedures. The second magnet, DCA312, was the ''technology transfer magnet'' and was built jointly by Fermilab and General Dynamics technicians. The next seven, DCA313- 319 are being built by General Dynamics personnel using Fermilab facilities and procedures. However, Fermilab personnel still operate the major tooling, provide the welders, perform assembly of items that would not be part of production magnets (e.g. voltage taps), and oversee the QA program. Five of these 7 GD-built magnets will be used in the Accelerator Systems String Test (ASST) to be carried out in Dallas later this year. The last four magnets, DCA320-323, are being built by Fermilab alone.

  18. Barriers to optimizing investments in the built environment to reduce youth obesity: policy-maker perspectives.

    PubMed

    Grant, Jill L; MacKay, Kathryn C; Manuel, Patricia M; McHugh, Tara-Leigh F

    2010-01-01

    To identify factors which limit the ability of local governments to make appropriate investments in the built environment to promote youth health and reduce obesity outcomes in Atlantic Canada. Policy-makers and professionals participated in focus groups to discuss the receptiveness of local governments to introducing health considerations into decision-making. Seven facilitated focus groups involved 44 participants from Atlantic Canada. Thematic discourse analysis of the meeting transcripts identified systemic barriers to creating a built environment that fosters health for youth aged 12-15 years. Participants consistently identified four categories of barriers. Financial barriers limit the capacities of local government to build, maintain and operate appropriate facilities. Legacy issues mean that communities inherit a built environment designed to facilitate car use, with inadequate zoning authority to control fast food outlets, and without the means to determine where schools are built or how they are used. Governance barriers derive from government departments with distinct and competing mandates, with a professional structure that privileges engineering, and with funding programs that encourage competition between municipalities. Cultural factors and values affect outcomes: people have adapted to car-oriented living; poverty reduces options for many families; parental fears limit children's mobility; youth receive limited priority in built environment investments. Participants indicated that health issues have increasing profile within local government, making this an opportune time to discuss strategies for optimizing investments in the built environment. The focus group method can foster mutual learning among professionals within government in ways that could advance health promotion.

  19. Rayleigh Scattering for Measuring Flow in a Nozzle Testing Facility

    NASA Technical Reports Server (NTRS)

    Gomez, Carlos R.; Panda, Jayanta

    2006-01-01

    A molecular Rayleigh-scattering-based air-density measurement system was built in a large nozzle-and-engine-component test facility for surveying supersonic plumes from jet-engine exhaust. A molecular Rayleigh-scattering-based air-density measurement system was built in a large nozzle-and-enginecomponent test facility for surveying supersonic plumes from jet-engine exhaust

  20. Facility Microgrids

    SciTech Connect

    Ye, Z.; Walling, R.; Miller, N.; Du, P.; Nelson, K.

    2005-05-01

    Microgrids are receiving a considerable interest from the power industry, partly because their business and technical structure shows promise as a means of taking full advantage of distributed generation. This report investigates three issues associated with facility microgrids: (1) Multiple-distributed generation facility microgrids' unintentional islanding protection, (2) Facility microgrids' response to bulk grid disturbances, and (3) Facility microgrids' intentional islanding.

  1. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    DOE PAGES

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; ...

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in themore » intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.« less

  2. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    PubMed

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  3. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    SciTech Connect

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; Perfetto, Anthony; Geckler, Sam; Partridge, William P.

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  4. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a recirculating control loop which had no water quality maintenance. Results show that periodic water maintenance can improve performance of the SWME. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage of this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing sublimator technology. The driver for the evaluation of water recirculation maintenance components was to enhance the robustness of the SWME through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A patented bed design that was developed for a United Technologies Aerospace System military application provided a low pressure drop means for water maintenance in the SWME recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for the ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  5. Anaerobic degradation of dairy wastewater in intermittent UASB reactors: influence of effluent recirculation.

    PubMed

    Couras, C S; Louros, V L; Gameiro, T; Alves, N; Silva, A; Capela, M I; Arroja, L M; Nadais, H

    2015-01-01

    This work studied the influence of effluent recirculation upon the kinetics of anaerobic degradation of dairy wastewater in the feedless phase of intermittent upflow anaerobic sludge bed (UASB) reactors. Several laboratory-scale tests were performed with different organic loads in closed circuit UASB reactors inoculated with adapted flocculent sludge. The data obtained were used for determination of specific substrate removal rates and specific methane production rates, and adjusted to kinetic models. A high initial substrate removal was observed in all tests due to adsorption of organic matter onto the anaerobic biomass which was not accompanied by biological substrate degradation as measured by methane production. Initial methane production rate was about 45% of initial soluble and colloidal substrate removal rate. This discrepancy between methane production rate and substrate removal rate was observed mainly on the first day of all experiments and was attenuated on the second day, suggesting that the feedless period of intermittent UASB reactors treating dairy wastewater should be longer than one day. Effluent recirculation expressively raised the rate of removal of soluble and colloidal substrate and methane productivity, as compared with results for similar assays in batch reactors without recirculation. The observed bed expansion was due to the biogas production and the application of effluent recirculation led to a sludge bed contraction after all the substrates were degraded. The settleability of the anaerobic sludge improved by the introduction of effluent recirculation this effect being more pronounced for the higher loads.

  6. The structure of the recirculation zone of a bluff-body combustor

    SciTech Connect

    Masri, A.R.; Dally, B.B.; Barlow, R.S.; Carter, C.D.

    1994-12-31

    The instantaneous mixing and reactive scalar fields have been measured in the recirculation zones of turbulent non-premixed flames stabilized on a bluff body, using the spontaneous Raman scattering technique. The measured means and rms fluctuations of mixture fraction, temperature, and the mass fractions of stable species are presented for various axial locations in the recirculation zone of CH{sub 4}/CO and CH{sub 4}/H{sub 2} flames. The diameters of the bluff body and the central fuel jet are 50 and 2 mm, respectively. Both flames are about 40 cm in length and have a full, luminous recirculation zone that extends for about one bluff-body diameter from the exit plane. Two regions of almost homogeneous mixture are identified within the recirculation zone: A large outer region, which on average is fuel lean, and an inner region, which is smaller and closer to the central fuel jet. Combustion is more intense in the inner region, where mean mixture fraction is stoichiometric and the peak values for temperature and mass fractions of combustion products are reached. Finite-rate chemical kinetic effects exist but not a high enough levels to cause localized extinction in the recirculation zone.

  7. Status of Centralized Environmental Creep Testing Facility Preparation and Upgrade

    SciTech Connect

    Ren, Weiju; Battiste, Rick

    2006-10-01

    Because the ASME Codes do not cover environmental issues that are crucial in the design and construction of VHTR system, investigation of long-term impure helium effects on metallurgical stability and properties becomes very important. The present report describes the development of centralized environmental creep testing facility, its close collaborations with the experiments in low velocity helium recirculation loop, important lessons learned, upgrades in system design in FY06, and current status of the development.

  8. Sodium recirculation and isotonic transport in toad small intestine.

    PubMed

    Nedergaard, S; Larsen, E H; Ussing, H H

    1999-04-01

    + fluxes, is compatible with convective flow of the two alkali metal ions through the same population of water-filled pores. With a new set of equations, the fraction of the sodium flux passing the basement membrane barrier of the lateral space that is recirculated through the cellular compartment is estimated. This fraction was, on average, 0.72 +/- 0.03 (N = 5). It is concluded that isotonicity of the transportate can be maintained by producing a hypertonic fluid emerging from the lateral space combined with reuptake of salt via the cells.

  9. Noscapine recirculates enterohepatically and induces self-clearance.

    PubMed

    Mukkavilli, Rao; Gundala, Sushma R; Yang, Chunhua; Jadhav, Gajanan R; Vangala, Subrahmanyam; Reid, Michelle D; Aneja, Ritu

    2015-09-18

    Noscapine (Nos), an antitussive benzylisoquinoline opium alkaloid, is a non-toxic tubulin-binding agent currently in Phase II clinical trials for cancer chemotherapy. While preclinical studies have established its tumor-inhibitory properties in various cancers, poor absorptivity and rapid first-pass metabolism producing several uncharacterized metabolites for efficacy, present an impediment in translating its efficacy in humans. Here we report novel formulations of Nos in combination with dietary agents like capsaicin (Cap), piperine (Pip), eugenol (Eu) and curcumin (Cur) known for modulating Phase I and II drug metabolizing enzymes. In vivo pharmacokinetic (PK), organ toxicity evaluation of combinations, microsomal stability and in vitro cytochrome P450 (CYP) inhibition effects of Nos, Cap and Pip using human liver microsomes were performed. Single-dose PK screening of combinations revealed that the relative exposure of Nos (2 μg h/mL) was enhanced by 2-fold (4 μg h/mL) by Cap and Pip and their plasma concentration-time profiles showed multiple peaking phenomena for Nos indicating enterohepatic recirculation or differential absorption from intestine. CYP inhibition studies confirmed that Nos, Cap and Pip are not potent CYP inhibitors (IC50>1 μM). Repeated oral dosing of Nos, Nos+Cap and Nos+Pip showed lower exposure (Cmax and AUClast) of Nos on day 7 compared to day 1. Nos Cmax decreased from 3087 ng/mL to 684 ng/mL and AUClast from 1024 ng h/mL to 508 ng h/mL. In presence of Cap and Pip, the decrease in Cmax and AUClast of Nos was similar. This may be due to potential enzyme induction leading to rapid clearance of Nos as the trend was observed in Nos alone group also. The lack of effect on intrinsic clearance of Nos suggests that the potential drug biotransformation modulators employed in this study did not contribute toward increased exposure of Nos on repeated dosing. We envision that Nos-induced enzyme induction could alter the therapeutic efficacy of co

  10. Blue Origin Facility - Construction Progress

    NASA Image and Video Library

    2017-03-21

    Construction is progressing on Blue Origin's 750,000-square-foot facility being built at Exploration Park on NASA Kennedy Space Center property in Florida. Blue Origin will use the factory to manufacture its two-stage super-heavy-lift New Glenn launch vehicle and launch the vehicles from Space Launch Complex 46 at Cape Canaveral Air Force Station.

  11. Using Campus Facilities for Marketing.

    ERIC Educational Resources Information Center

    Carmichael, Bruce

    1992-01-01

    College buildings, interiors, furniture, spaces, landscaping, and equipment express what the college stands for, what it cares most about, and how it views the intellectual and aesthetic enterprise. Well-designed and well-built physical facilities, especially those that are distinctive, should be a more recognized force in any college's enrollment…

  12. PAINT SPRAY BOOTH DESIGN USING RECIRCULATION/PARTITIONING VENTILATION

    EPA Science Inventory

    Many spray painting facility operators have been attempting to reduce the discharge of volatile organic compounds (VOCs) from paint spray booths to the atmosphere. Some have been able to convert to lower VOC containing paints and coatings such as powder coating, waterborne coatin...

  13. PAINT SPRAY BOOTH DESIGN USING RECIRCULATION/PARTITIONING VENTILATION

    EPA Science Inventory

    Many spray painting facility operators have been attempting to reduce the discharge of volatile organic compounds (VOCs) from paint spray booths to the atmosphere. Some have been able to convert to lower VOC containing paints and coatings such as powder coating, waterborne coatin...

  14. Home and workplace built environment supports for physical activity.

    PubMed

    Adlakha, Deepti; Hipp, Aaron J; Marx, Christine; Yang, Lin; Tabak, Rachel; Dodson, Elizabeth A; Brownson, Ross C

    2015-01-01

    Physical inactivity has been associated with obesity and related chronic diseases. Understanding built environment (BE) influences on specific domains of physical activity (PA) around homes and workplaces is important for public health interventions to increase population PA. To examine the association of home and workplace BE features with PA occurring across specific life domains (work, leisure, and travel). Between 2012 and 2013, telephone interviews were conducted with participants in four Missouri metropolitan areas. Questions included sociodemographic characteristics, home and workplace supports for PA, and dietary behaviors. Data analysis was conducted in 2013; logistic regression was used to examine associations between BE features and domain-specific PA. In home neighborhoods, seven of 12 BE features (availability of fruits and vegetables, presence of shops and stores, bike facilities, recreation facilities, crime rate, seeing others active, and interesting things) were associated with leisure PA. The global average score of home neighborhood BE features was associated with greater odds of travel PA (AOR=1.99, 95% CI=1.46, 2.72); leisure PA (AOR=1.84, 95% CI=1.44, 2.34); and total PA (AOR=1.41, 95% CI=1.04, 1.92). Associations between workplace neighborhoods' BE features and workplace PA were small but in the expected direction. This study offers empirical evidence on BE supports for domain-specific PA. Findings suggest that diverse, attractive, and walkable neighborhoods around workplaces support walking, bicycling, and use of public transit. Public health practitioners, researchers, and worksite leaders could benefit by utilizing worksite domains and measures from this study for future BE assessments. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  15. National Built Environment Health Impact Assessment Model ...

    EPA Pesticide Factsheets

    Behavioral (activity, diet, social interaction) and exposure (air pollution, traffic injury, and noise) related health impacts of land use and transportation investment decisions are becoming better understood and quantified. Research has shown relationships between density, mix, street connectivity, access to parks, shops, transit, presence of sidewalks and bikeways, and healthy food with physical activity, obesity, cardiovascular disease, type II diabetes, and some mental health outcomes. This session demonstrates successful integration of health impact assessment into multiple scenario planning tool platforms. Detailed evidence on chronic disease and related costs associated with contrasting land use and transportation investments are built into a general-purpose module that can be accessed by multiple platforms. Funders, researchers, and end users of the tool will present a detailed description of the key elements of the approach, how it has been applied, and how will evolve. A critical focus will be placed on equity and social justice inherent within the assessment of health disparities that will be featured in the session. Health impacts of community design have significant cost benefit implications. Recent research is now extending relationships between community design features and chronic disease to health care costs. This session will demonstrate the recent application of this evidence on health impacts to the newly adopted Los Angeles Regional Transpo

  16. A scalable neuristor built with Mott memristors

    NASA Astrophysics Data System (ADS)

    Pickett, Matthew D.; Medeiros-Ribeiro, Gilberto; Williams, R. Stanley

    2013-02-01

    The Hodgkin-Huxley model for action potential generation in biological axons is central for understanding the computational capability of the nervous system and emulating its functionality. Owing to the historical success of silicon complementary metal-oxide-semiconductors, spike-based computing is primarily confined to software simulations and specialized analogue metal-oxide-semiconductor field-effect transistor circuits. However, there is interest in constructing physical systems that emulate biological functionality more directly, with the goal of improving efficiency and scale. The neuristor was proposed as an electronic device with properties similar to the Hodgkin-Huxley axon, but previous implementations were not scalable. Here we demonstrate a neuristor built using two nanoscale Mott memristors, dynamical devices that exhibit transient memory and negative differential resistance arising from an insulating-to-conducting phase transition driven by Joule heating. This neuristor exhibits the important neural functions of all-or-nothing spiking with signal gain and diverse periodic spiking, using materials and structures that are amenable to extremely high-density integration with or without silicon transistors.

  17. National Built Environment Health Impact Assessment Model ...

    EPA Pesticide Factsheets

    Behavioral (activity, diet, social interaction) and exposure (air pollution, traffic injury, and noise) related health impacts of land use and transportation investment decisions are becoming better understood and quantified. Research has shown relationships between density, mix, street connectivity, access to parks, shops, transit, presence of sidewalks and bikeways, and healthy food with physical activity, obesity, cardiovascular disease, type II diabetes, and some mental health outcomes. This session demonstrates successful integration of health impact assessment into multiple scenario planning tool platforms. Detailed evidence on chronic disease and related costs associated with contrasting land use and transportation investments are built into a general-purpose module that can be accessed by multiple platforms. Funders, researchers, and end users of the tool will present a detailed description of the key elements of the approach, how it has been applied, and how will evolve. A critical focus will be placed on equity and social justice inherent within the assessment of health disparities that will be featured in the session. Health impacts of community design have significant cost benefit implications. Recent research is now extending relationships between community design features and chronic disease to health care costs. This session will demonstrate the recent application of this evidence on health impacts to the newly adopted Los Angeles Regional Transpo

  18. The Built Environment Is a Microbial Wasteland

    PubMed Central

    2016-01-01

    ABSTRACT Humanity’s transition from the outdoor environment to the built environment (BE) has reduced our exposure to microbial diversity. The relative importance of factors that contribute to the composition of human-dominated BE microbial communities remains largely unknown. In their article in this issue, Chase and colleagues (J. Chase, J. Fouquier, M. Zare, D. L. Sonderegger, R. Knight, S. T. Kelley, J. Siegel, and J. G. Caporaso, mSystems 1(2):e00022-16, 2016, http://dx.doi.org/10.1128/mSystems.00022-16) present an office building study in which they controlled for environmental factors, geography, surface material, sampling location, and human interaction type. They found that surface location and geography were the strongest factors contributing to microbial community structure, while surface material had little effect. Even in the absence of direct human interaction, BE surfaces were composed of 25 to 30% human skin-associated taxa. The authors demonstrate how technical variation across sequencing runs is a major issue, especially in BE work, where the biomass is often low and the potential for PCR contaminants is high. Overall, the authors conclude that BE surfaces are desert-like environments where microbes passively accumulate. PMID:27832216

  19. Endolithic phototrophs in built and natural stone.

    PubMed

    Gaylarde, Christine C; Gaylarde, Peter M; Neilan, Brett A

    2012-08-01

    Lichens, algae and cyanobacteria have been detected growing endolithically in natural rock and in stone buildings in various countries of Australasia, Europe and Latin America. Previously these organisms had mainly been described in natural carbonaceous rocks in aquatic environments, with some reports in siliceous rocks, principally from extremophilic regions. Using various culture and microscopy methods, we have detected endoliths in siliceous stone, both natural and cut, in humid temperate and subtropical climates. Such endolithic growth leads to degradation of the stone structure, not only by mechanical means, but also by metabolites liberated by the cells. Using in vitro culture, transmission, optical and fluorescence microscopy, and confocal laser scanning microscopy, both coccoid and filamentous cyanobacteria and algae, including Cyanidiales, have been identified growing endolithically in the facades of historic buildings built from limestone, sandstone, granite, basalt and soapstone, as well as in some natural rocks. Numerically, the most abundant are small, single-celled, colonial cyanobacteria. These small phototrophs are difficult to detect by standard microscope techniques and some of these species have not been previously reported within stone.

  20. Biofilms in churches built in grottoes.

    PubMed

    Cennamo, Paola; Montuori, Naomi; Trojsi, Giorgio; Fatigati, Giancarlo; Moretti, Aldo

    2016-02-01

    We investigated microorganisms dwelling on rocks, walls and paintings in two votive chapels built in grottoes in the Region of Campania, Italy. One grotto was near the coast in an area with a Mediterranean climate, and the other grotto was inland on a mountain in an area with a cold continental climate. Color and distribution of biofilms in various areas of the grottoes were examined. Microbial components of biofilms were identified by light and electron microscopy and by molecular techniques (DNA analyses and Automatic rRNA Intergenic Spacer Analysis). Biofilms were also analyzed by X-ray diffraction to detect inorganic constituents deriving from rocks in the grottoes and walls of the churches and by X-ray fluorescence to detect the elements that made up the pigments of the mural paintings; optical cross sections were used to observe their relationships with substrata. Species of eubacteria, cyanobacteria and green algae were identified. Some of these species occurred in both grottoes, while others were exclusive to only one of the grottoes. The diversity of species, their common or exclusive occurrence in the grottoes, the relationships among microbial communities and the differences in color and distribution of biofilms were discussed on the basis of the different climatic factors affecting the two grottoes and the different inorganic components of substrata. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Built-in lens mask lithography

    NASA Astrophysics Data System (ADS)

    Ueda, Naoki; Sasago, Masaru; Misaka, Akio; Kikuta, Hisao; Kawata, Hiroaki; Hirai, Yoshihiko

    2014-03-01

    Cost effective micro lithography tool is demanded for fine micro devices. However, resolution of a conventional proximity exposure system is not sufficient below several micron feature size for deep focus depth. On the other hand, a reduction projection system is sufficient to resolve it but the cost of the tool is too much high compared to proximity exposure systems. To enhance the resolution of photolithography, there has been proposed a number of novel methods beside shorting of wave length. Some of them are utilized in current advanced lithography systems, for example, the immersion lithography1 enhances effective NA and the phase shift mask2 improves optical transmittance function. However, those advanced technology is mainly focused on improvement for advanced projection exposure systems for ultra-fine lithography. On the other hand, coherence holography pattering is recently proposed and expected for 3-dimentional pattering3-5. Also, Talbot lithography6-8 is studied for periodical micro and nano pattering. Those novels pattering are based on wave propagation due to optical diffraction without using expensive optical lens systems. In this paper we newly propose novel optical lithography using built-in lens mask to enhance resolution and focus depth in conventional proximity exposure system for micro lithographic application without lens systems. The performance is confirmed by simulation and experimental works.

  2. Multi-Point Interferometric Rayleigh Scattering using Dual-Pass Light Recirculation

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Cutler, Andrew D.

    2008-01-01

    This paper describes for the first time an interferometric Rayleigh scattering system using dual-pass light recirculation (IRS-LR) capable of simultaneously measuring at multiple points two orthogonal components of flow velocity in combustion flows using single shot laser probing. An additional optical path containing the interferometer input mirror, a quarter-wave plate, a polarization dependent beam combiner, and a high reflectivity mirror partially recirculates the light that is rejected by the interferometer. Temporally- and spatially-resolved acquisitions of Rayleigh spectra in a large-scale combustion-heated supersonic axi-symmetric jet were performed to demonstrate the technique. Recirculating of Rayleigh scattered light increases the number of photons analyzed by the system up to a factor of 1.8 compared with previous configurations. This is equivalent to performing measurements with less laser energy or performing measurements with the previous system in gas flows at higher temperatures.

  3. Saponification pretreatment and solids recirculation as a new anaerobic process for the treatment of slaughterhouse waste.

    PubMed

    Affes, R; Palatsi, J; Flotats, X; Carrère, H; Steyer, J P; Battimelli, A

    2013-03-01

    Different configurations of anaerobic process, adapted to the treatment of solid slaughterhouse fatty waste, were proposed and evaluated in this study. The tested configurations are based on the combination of anaerobic digestion with/without waste saponification pretreatment (70 °C during 60 min) and with/without recirculation of the digestate solid fraction (ratio=20% w/w). After an acclimation period of substrate pulses-feeding cycles, the reactors were operated in a semi-continuous feeding mode, increasing organic loading rates along experimental time. The degradation of the raw substrate was shown to be the bottleneck of the whole process, obtaining the best performance and process yields in the reactor equipped with waste pretreatment and solids recirculation. Saponification promoted the emulsification and bioavailability of solid fatty residues, while recirculation of solids minimized the substrate/biomass wash-out and induced microbial adaptation to the treatment of fatty substrates.

  4. Environmental performance of air staged combustor with flue gas recirculation to burn coal/biomass

    SciTech Connect

    Anuar, S.H.; Keener, H.M.

    1995-12-31

    The environmental and thermal performance of a 1.07 m diameter, 440 kW atmospheric fluidized bed combustor operated at 700{degrees}C-920{degrees}C and burning coal was studied. Flue gas recirculation was incorporated to enhance the thermal performance and air staging was used to control emissions of SO{sub 2}, CO, NO{sub x} and N{sub 2}O. Studies focused on the effect of excess air, firing rate, and use of sorbent on system performance. The recirculation-staging mode with limestone had the highest thermal efficiency (0.67) using the firing equation. Emission data showed that flue gas recirculation (ratio of 0.7) significantly reduced NO{sub x} emissions; and that use of limestone sorbent at a Ca/S ratio of 3 reduced SO{sub 2} emissions by 64% to approximately 0.310 g/MJ.

  5. Interaction of Particles with Recirculating Flow Regions inside Cavities of Inertial Microchannels

    NASA Astrophysics Data System (ADS)

    Haddadi, Hamed; di Carlo, Dino

    2015-11-01

    Confined inertial flow over cavities of a microfluidic device leads to formation of recirculating flow regions, i.e flow cells, inside cavities which can entrap particles from the free stream. Besides its significance as a fundamental problem in fluid mechanics of mixtures, understanding particle interaction with recirculating flow regions inside cavities is important in biomedical applications, such as Circulating Tumor Cell (CTC) separation and platelet deposition in arterial stenosis. In the present work, a lattice-Boltzmann model with resolved particle-corner interaction combined with microfluidic experiments enabled improved understanding of the particle exchange within flow cells in confined inertial flow. Formation of a limit cycle trajectory, observed in experiments and numerical simulations, is a key feature in particle accumulation. By varying the dimensions of the cavity and channel Reynolds number, The length and location of the limit cycle trajectory also varies, altering of the rate of particle exchange and level of accumulation with recirculating zones inside cavities.

  6. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    DOEpatents

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  7. Investigation of hydrocarbon oil transformation by gliding arc discharge: comparison of batch and recirculated configurations

    NASA Astrophysics Data System (ADS)

    Whitehead, J. Christopher; Prantsidou, Maria

    2016-04-01

    The degradation of liquid dodecane was studied in a gliding arc discharge (GAD) of humid argon or nitrogen. A batch or recirculating configuration was used. The products in the gaseous and liquid phase were analysed by infrared and chromatography and optical emission spectroscopy was used to identify the excited species in the discharge. The best degradation performance comes from the use of humid N2 but a GAD of humid argon produces fewer gas-phase products but more liquid-phase end-products. A wide range of products such as heavier saturated or unsaturated hydrocarbons both aliphatic and aromatic, and oxidation products mainly alcohols, but also aldehydes, ketones and esters are produced in the liquid-phase. The recirculating treatment mode is more effective than the batch mode increasing the reactivity and changing the product selectivities. Overall, the study shows promising results for the organic liquid waste treatment, especially in the recirculating mode.

  8. Physics issues in the design of a recirculating induction accelerator for heavy ion fusion

    SciTech Connect

    Barnard, J.J.; Newton, M.A.; Reginato, L.L.; Sharp, W.M.; Yu, S.S.

    1991-04-15

    A substantial savings in size and cost over a linear machine may be achieved in an induction accelerator in which a heavy ion beam makes many (< {approximately} 50) passes through one or more circular induction accelerators. We examine how the requirement of high beam quality and the requirement of pulse simultaneity at the target constrain the design of such an accelerator. Some of the issues that we have considered include beam interactions with residual gas, beam-beam charge exchange, emittance growth around bends, and beam instabilities. We show some of the interplay between maximization of beam quality and recirculator efficiency, and the minimization of recirculator cost, in arriving at a recirculator design. 9 refs., 1 fig.

  9. Impact of different recirculation schemes on nitrogen removal and overall performance of a laboratory scale MBR.

    PubMed

    Bracklow, U; Manigas, L; Drews, A; Vocks, M; Barjenbruch, M; Kraume, M

    2007-01-01

    For membrane bioreactors (MBR) with enhanced nutrients removal, rather complex recirculation schemes based on the biological requirements are commonly recommended. The aim of this work was to evaluate other recirculation options. For a laboratory scale MBR, four different recirculation schemes were tested. The MBR was operated with COD degradation, nitrification, post-denitrification without carbon dosing and biological phosphorus removal. For all configurations, efficient COD, nitrogen and phosphorus removal could be achieved. There were no big differences in elimination efficiency between the configurations (COD elimination: 96.6-97.9%, nitrogen removal: 89.7-92.1% and phosphorus removal: 97.4-99.4%). Changes in the degradation, release and uptake rates were levelled out by the changes in contact time and biomass distribution. With relatively constant outflow concentrations, different configurations are still interesting with regard to oxygen consumption, simplicity of plant operation or support of certain degradation pathways such as biological phosphorus removal or denitrification.

  10. Recurrent amoebic gill infestation in rainbow trout cultured in a semiclosed water recirculation system

    USGS Publications Warehouse

    Noble, A.C.; Herman, R.L.; Noga, E.J.; Bullock, G.L.

    1997-01-01

    Five lots of commercially purchased juvenile rainbow trout Oncorhynchus mykiss (17-44 g) stocked in a continuous-production water recirculation system became infested with gilt amoebae. The amoebae were introduced into the recirculation system, as evidenced by their presence on gills of fish held in quarantine tanks. Based on their morphology, as seen in histological sections and by electron microscopy, the amoebae appeared to be more closely related to the family Cochliopodiidae than to other taxa of free living amoebae. Attempts to culture the amoebae in different media, at different temperatures of incubation, and in fish cell culture were not successful. Initial treatment of the recirculation system with formalin at 167 parts per million (ppm) for 1 h eliminated amoebae from the gills. Subsequent treatments of the entire system with formalin at 50-167 ppm reduced the intensity of further infestations.

  11. KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility check out the Window Observational Research Facility (WORF), designed and built by the Boeing Co. at NASA’s Marshall Space Flight Center in Huntsville, Ala. WORF will be delivered to the International Space Station and placed in the rack position in front of the Destiny lab window, providing locations for attaching cameras, multi-spectral scanners and other instruments. WORF will support a variety of scientific and commercial experiments in areas of Earth systems and processes, global ecological changes in Earth’s biosphere, lithosphere, hydrosphere and climate system, Earth resources, natural hazards, and education. After installation, it will become a permanent focal point for Earth Science research aboard the space station.

    NASA Image and Video Library

    2003-09-08

    KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility check out the Window Observational Research Facility (WORF), designed and built by the Boeing Co. at NASA’s Marshall Space Flight Center in Huntsville, Ala. WORF will be delivered to the International Space Station and placed in the rack position in front of the Destiny lab window, providing locations for attaching cameras, multi-spectral scanners and other instruments. WORF will support a variety of scientific and commercial experiments in areas of Earth systems and processes, global ecological changes in Earth’s biosphere, lithosphere, hydrosphere and climate system, Earth resources, natural hazards, and education. After installation, it will become a permanent focal point for Earth Science research aboard the space station.

  12. KENNEDY SPACE CENTER, FLA. - The Window Observational Research Facility (WORF), seen in the Space Station Processing Facility, was designed and built by the Boeing Co. at NASA’s Marshall Space Flight Center in Huntsville, Ala. WORF will be delivered to the International Space Station and placed in the rack position in front of the Destiny lab window, providing locations for attaching cameras, multi-spectral scanners and other instruments. WORF will support a variety of scientific and commercial experiments in areas of Earth systems and processes, global ecological changes in Earth’s biosphere, lithosphere, hydrosphere and climate system, Earth resources, natural hazards, and education. After installation, it will become a permanent focal point for Earth Science research aboard the space station.

    NASA Image and Video Library

    2003-09-08

    KENNEDY SPACE CENTER, FLA. - The Window Observational Research Facility (WORF), seen in the Space Station Processing Facility, was designed and built by the Boeing Co. at NASA’s Marshall Space Flight Center in Huntsville, Ala. WORF will be delivered to the International Space Station and placed in the rack position in front of the Destiny lab window, providing locations for attaching cameras, multi-spectral scanners and other instruments. WORF will support a variety of scientific and commercial experiments in areas of Earth systems and processes, global ecological changes in Earth’s biosphere, lithosphere, hydrosphere and climate system, Earth resources, natural hazards, and education. After installation, it will become a permanent focal point for Earth Science research aboard the space station.

  13. KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, is secured on a transporter after its arrival at the Shuttle Landing Facility. It will be taken to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

    NASA Image and Video Library

    2003-06-02

    KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, is secured on a transporter after its arrival at the Shuttle Landing Facility. It will be taken to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

  14. KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, arrives at the Space Station Processing Facility after its move from the Shuttle Landing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

    NASA Image and Video Library

    2003-06-02

    KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, arrives at the Space Station Processing Facility after its move from the Shuttle Landing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

  15. KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, is lowered onto a transporter after its arrival at the Shuttle Landing Facility. It will be taken to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

    NASA Image and Video Library

    2003-06-02

    KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, is lowered onto a transporter after its arrival at the Shuttle Landing Facility. It will be taken to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

  16. KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, begins its transfer from the Shuttle Landing Facility to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

    NASA Image and Video Library

    2003-06-02

    KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, begins its transfer from the Shuttle Landing Facility to the Space Station Processing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

  17. KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, nears the Space Station Processing Facility after its move from the Shuttle Landing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

    NASA Image and Video Library

    2003-06-02

    KENNEDY SPACE CENTER, FLA. - The Italian-built module, U.S. Node 2, nears the Space Station Processing Facility after its move from the Shuttle Landing Facility. The second of three connecting modules on the International Space Station, Node 2 attaches to the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet.

  18. KENNEDY SPACE CENTER, FLA. - Dignitaries, invited guests, space center employees, and the media gather for a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

    NASA Image and Video Library

    2003-11-19

    KENNEDY SPACE CENTER, FLA. - Dignitaries, invited guests, space center employees, and the media gather for a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

  19. KENNEDY SPACE CENTER, FLA. - Capt. Winston Scott, executive director of the Florida Space Authority, speaks at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

    NASA Image and Video Library

    2003-11-19

    KENNEDY SPACE CENTER, FLA. - Capt. Winston Scott, executive director of the Florida Space Authority, speaks at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

  20. KENNEDY SPACE CENTER, FLA. - Frank T. Brogan, president of the Florida Atlantic University, speaks at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

    NASA Image and Video Library

    2003-11-19

    KENNEDY SPACE CENTER, FLA. - Frank T. Brogan, president of the Florida Atlantic University, speaks at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

  1. KENNEDY SPACE CENTER, FLA. - Dignitaries, invited guests, space center employees, and the media show their appreciation for the speakers at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

    NASA Image and Video Library

    2003-11-19

    KENNEDY SPACE CENTER, FLA. - Dignitaries, invited guests, space center employees, and the media show their appreciation for the speakers at a dedication and ribbon-cutting ceremony for the Space Life Sciences Lab hosted by NASA-Kennedy Space Center and the state of Florida at the new lab. Completed in August, the facility encompasses more than 100,000 square feet and was formerly known as the Space Experiment Research and Processing Laboratory or SERPL. The state, through the Florida Space Authority, built the research lab which is host to NASA, NASA’s Life Sciences Services contractor Dynamac Corp., Bionetics Corp., and researchers from the University of Florida. Dynamac Corp. leases the facility. The Florida Space Research Institute is responsible for gaining additional tenants from outside the NASA community.

  2. Rendezvous facilities

    SciTech Connect

    Gehani, N.H.; Roome, W.D.

    1988-11-01

    The concurrent programming facilities in both Concurrent C and the Ada language are based on the rendezvous concept. Although these facilities are similar, there are substantial differences. Facilities in Concurrent C were designed keeping in perspective the concurrent programming facilities in the Ada language and their limitations. Concurrent C facilities have also been modified as a result of experience with its initial implementations. In this paper, the authors compare the concurrent programming facilities in Concurrent C and Ada, and show that it is easier to write a variety of concurrent programs in Concurrent C than in Ada.

  3. NETL's Hybrid Performance, or Hyper, facility

    ScienceCinema

    None

    2016-07-12

    NETL's Hybrid Performance, or Hyper, facility is a one-of-a-kind laboratory built to develop control strategies for the reliable operation of fuel cell/turbine hybrids and enable the simulation, design, and implementation of commercial equipment. The Hyper facility provides a unique opportunity for researchers to explore issues related to coupling fuel cell and gas turbine technologies.

  4. NETL's Hybrid Performance, or Hyper, facility

    SciTech Connect

    2013-06-12

    NETL's Hybrid Performance, or Hyper, facility is a one-of-a-kind laboratory built to develop control strategies for the reliable operation of fuel cell/turbine hybrids and enable the simulation, design, and implementation of commercial equipment. The Hyper facility provides a unique opportunity for researchers to explore issues related to coupling fuel cell and gas turbine technologies.

  5. Consolidated Incineration Facility Tritium Emissions Monitoring

    SciTech Connect

    Dunn, D. L.; Aggus, J.R.

    1995-03-29

    The Savannah River Technology Center, a research and development facility at the US Department of Energy`s Savannah River Site, provides environmental and regulatory compliance support to onsite operations. A new consolidated Incinerator Facility at SRS is being built to treat hazardous and a combination of hazardous and radioactive (mixed) wastes.

  6. The Louisiana ACES Student-built BalloonSat Program

    NASA Astrophysics Data System (ADS)

    Ellison, B.; Giammanco, J.; Guzik, T. G.; Johnson, K.; Wefel, J. P.

    The Aerospace Catalyst Experiences for Students (ACES) pilot project was funded at Louisiana State University by NASA's National Space Grant College and Fellowship program during the 2002-2003 academic year with the primary goal of giving students a true hands-on experience with project management, life-cycle, experiment construction, data collection, analysis and interpretation. In this project students design, build, fly and analyze the data returned from small payloads (typical dimensions 10 cm x 10 cm x 10 cm, typical weight ˜ 500 grams) carried up to ˜ 100,000 feet by a helium-filled latex sounding balloon. During the pilot project the 13 students that participated in the program, grouped in 4 teams, built payloads that included studies in atmospheric science, cosmic rays and remote sensing. These payloads were then launched from the NASA National Scientific Balloon Facility in Palestine, Texas on May 21, 2003. Most recently, the LaACES (Louisiana ACES) program has been selected for funding by NASA. During LaACES we will expand the pilot program to institutions across the state including developing student training materials, holding a workshop for institution representatives, awarding payload development grants to student teams, monitoring the progress of these teams and supporting the balloon flight of the completed payloads. Here we describe the ACES pilot, the outcomes, and plans for La ACES.

  7. Extent of flow recirculation governs expression of atherosclerotic and thrombotic biomarkers in arterial bifurcations

    PubMed Central

    Martorell, Jordi; Santomá, Pablo; Kolandaivelu, Kumaran; Kolachalama, Vijaya B.; Melgar-Lesmes, Pedro; Molins, José J.; Garcia, Lawrence; Edelman, Elazer R.; Balcells, Mercedes

    2014-01-01

    Aims Atherogenesis, evolution of plaque, and outcomes following endovascular intervention depend heavily on the unique vascular architecture of each individual. Patient-specific, multiscale models able to correlate changes in microscopic cellular responses with relevant macroscopic flow, and structural conditions may help understand the progression of occlusive arterial disease, providing insights into how to mitigate adverse responses in specific settings and individuals. Methods and results Vascular architectures mimicking coronary and carotid bifurcations were derived from clinical imaging and used to generate conjoint computational meshes for in silico analysis and biocompatible scaffolds for in vitro models. In parallel with three-dimensional flow simulations, geometrically realistic scaffolds were seeded with human smooth muscle cells (SMC) or endothelial cells and exposed to relevant, physiological flows. In vitro surrogates of endothelial health, atherosclerotic progression, and thrombosis were locally quantified and correlated best with an quantified extent of flow recirculation occurring within the bifurcation models. Oxidized low-density lipoprotein uptake, monocyte adhesion, and tissue factor expression locally rose up to three-fold, and phosphorylated endothelial nitric oxide synthase and Krüppel-like factor 2 decreased up to two-fold in recirculation areas. Isolated testing in straight-tube idealized constructs subject to static, oscillatory, and pulsatile conditions, indicative of different recirculant conditions corroborated these flow-mediated dependencies. Conclusions Flow drives variations in vascular reactivity and vascular beds. Endothelial health was preserved by arterial flow but jeopardized in regions of flow recirculation in a quasi-linear manner. Similarly, SMC exposed to flow were more thrombogenic in large recirculating regions. Health, thrombosis, and atherosclerosis biomarkers correlate with the extent of recirculation in vascular

  8. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    SciTech Connect

    Sarker, M. R. I. Saha, Manabendra E-mail: manab04me@gmail.com; Beg, R. A.

    2016-07-12

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.

  9. Contribution of seawater recirculation to submarine groundwater discharge and related nutrient fluxes in two tropical bays

    NASA Astrophysics Data System (ADS)

    Vautier, Camille; Dulaiova, Henrietta

    2017-04-01

    Hawaiian coastal waters suffer from excess terrestrial nutrient loading, most of which comes from submarine groundwater discharge (SGD). This study quantifies and distinguishes the role of the fresh terrestrial and tidally pumped salt water components of SGD into the nearshore zone of two reefs on the island of Oahu: Maunalua Bay and Kāneohe Bay. The two components of SGD are characterized using isotopic techniques, and the study mainly focuses on the less understood recirculation component. A two-step approach is implemented: first, a conceptual model of groundwater circulation is established; second, nutrient fluxes associated with seawater recirculation are quantified. Groundwater circulation through the beach berm is quantified and characterized using 222Rn and 224Ra activity measurements. Nutrient fluxes are obtained by coupling nutrient concentration measurements and discharge estimates. The isotopic signatures inform us about the influence of the tidal cycle on groundwater circulation. 222Rn, 224Ra, and δ18O isotopes are used to derive apparent ages of the infiltrated seawater and allow us to quantify recirculation rates. The method is also complemented with the use of silicate concentration as tracers of the recirculation process. The trends in apparent ages observed in pore water in Maunalua match previously published conceptual groundwater circulation models and show a sequentially aging pore water circulation loop. However, the ages obtained in Kāneohe suggest a different tidal pumping dynamic that lacks a circulation loop, perhaps resulting from the absence of freshwater discharge. Derived nutrient fluxes show that the autochthonous production of inorganic nitrogen and phosphorus that occurs during seawater recirculation has a significant impact on nutrient cycles in the nearshore areas of the bays. This result suggests that seawater recirculation should be taken into account in biogeochemical studies of coastal areas.

  10. Methane emissions from MSW landfill with sandy soil covers under leachate recirculation and subsurface irrigation

    NASA Astrophysics Data System (ADS)

    Zhang, Houhu; He, Pinjing; Shao, Liming

    CH 4 emissions and leachate disposal are recognized as the two major concerns in municipal solid waste (MSW) landfills. Recently, leachate recirculation was attempted to accelerate land-filled waste biodegradation and thus enhanced landfill gas generation. Leachate irrigation was also conducted for volume reduction effectively. Nevertheless, the impacts of leachate recirculation and irrigation on landfill CH 4 emissions have not been previously reported. A field investigation of landfill CH 4 emissions was conducted on selected sandy soil cover with leachate recirculation and subsurface irrigation based on whole year around measurement. The average CH 4 fluxes were 311±903, 207±516, and 565±1460 CH 4 m -2 h -1 from site A without leachate recirculation and subsurface irrigation, lift B2 with leachate subsurface irrigation, and lift B1 with both leachate recirculation and subsurface irrigation, respectively. Both gas recovery and cover soil oxidation minimized CH 4 emissions efficiently, while the later might be more pronounced when the location was more than 5 m away from gas recovery well. After covered by additional clay soil layer, CH 4 fluxes dropped by approximately 35 times in the following three seasons compared to the previous three seasons in lift B2. The diurnal peaks of CH 4 fluxes occurred mostly followed with air or soil temperature in the daytimes. The measured CH 4 fluxes were much lower than those of documented data from the landfills, indicating that the influences of leachate recirculation and subsurface irrigation on landfill CH 4 emissions might be minimized with the help of a well-designed sandy soil cover. Landfill cover composed of two soil layers (clay soil underneath and sandy soil above) is suggested as a low-cost and effective alternative to minimize CH 4 emissions.

  11. The effect of upstream buildings on near-field pollutant dispersion in the built environment

    NASA Astrophysics Data System (ADS)

    Hajra, B.; Stathopoulos, T.; Bahloul, A.

    2011-09-01

    This paper examines the effects of near-field pollutant dispersion characteristics of upstream buildings in the built environment and compares them to the ASHRAE 2007 model. Wind tunnel simulations were performed for nine different building configurations for three exhaust momentum ratios ( M) and three stack heights ( hs). The effect of spacing ( S) between the buildings and stack location from the upwind edge of the emitting building ( X) were also investigated. Measurements of gas concentrations were performed on the roof and leeward wall of the emitting and upstream buildings. Data show that within the recirculation zone a change in along wind dimension of the upstream building has a negligible effect on the dilution of emissions from the downwind building. However, spacing between buildings and the height of the upstream building were found to be critical parameters in assessing plume dilution. The plume geometry is largely governed by the upwind dimensions of the upstream building. ASHRAE (2007) predicts lower dilution for all cases examined, leading to conservative or very conservative design. However, the ASHRAE 2007 cannot model the effect of upstream buildings, thus further investigation of its formulations is required. Guidelines for placement of intake and stack on the roof of the building to avoid problems of re-ingestion are discussed.

  12. Sequestering CO2 in the Built Environment

    NASA Astrophysics Data System (ADS)

    Constantz, B. R.

    2009-12-01

    Calera’s Carbonate Mineralization by Aqueous Precipitation (CMAP) technology with beneficial reuse has been called, “game-changing” by Carl Pope, Director of the Sierra Club. Calera offers a solution to the scale of the carbon problem. By capturing carbon into the built environment through carbonate mineralization, Calera provides a sound and cost-effective alternative to Geologic Sequestration and Terrestrial Sequestration. The CMAP technology permanently converts carbon dioxide into a mineral form that can be stored above ground, or used as a building material. The process produces a suite of carbonate-containing minerals of various polymorphic forms. Calera product can be substituted into blends with ordinary Portland cements and used as aggregate to produce concrete with reduced carbon, carbon neutral, or carbon negative footprints. For each ton of product produced, approximately half a ton of carbon dioxide can be sequestered using the Calera process. Coal and natural gas are composed of predominately istopically light carbon, as the carbon in the fuel is plant-derived. Thus, power plant CO2 emissions have relatively low δ13C values.The carbon species throughout the CMAP process are identified through measuring the inorganic carbon content, δ13C values of the dissolved carbonate species, and the product carbonate minerals. Measuring δ13C allows for tracking the flue gas CO2 throughout the capture process. Initial analysis of the capture of propane flue gas (δ13C ˜ -25 ‰) with seawater (δ13C ˜ -10 ‰) and industrial brucite tailings from a retired magnesium oxide plant in Moss Landing, CA (δ13C ˜ -7 ‰ from residual calcite) produced carbonate mineral products with a δ13C value of ˜ -20 ‰. This isotopically light carbon, transformed from flue gas to stable carbonate minerals, can be transferred and tracked through the capture process, and finally to the built environment. CMAP provides an economical solution to global warming by producing

  13. 47 CFR 15.23 - Home-built devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Home-built devices. 15.23 Section 15.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.23 Home-built... constructed from a kit, and are built in quantities of five or less for personal use. (b) It is...

  14. 47 CFR 15.23 - Home-built devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Home-built devices. 15.23 Section 15.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.23 Home-built... constructed from a kit, and are built in quantities of five or less for personal use. (b) It is...

  15. 46 CFR 67.97 - United States built.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false United States built. 67.97 Section 67.97 Shipping COAST... DOCUMENTATION OF VESSELS Build Requirements for Vessel Documentation § 67.97 United States built. To be considered built in the United States a vessel must meet both of the following criteria: (a) All...

  16. 46 CFR 67.97 - United States built.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false United States built. 67.97 Section 67.97 Shipping COAST... DOCUMENTATION OF VESSELS Build Requirements for Vessel Documentation § 67.97 United States built. To be considered built in the United States a vessel must meet both of the following criteria: (a) All...

  17. 46 CFR 67.97 - United States built.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false United States built. 67.97 Section 67.97 Shipping COAST... DOCUMENTATION OF VESSELS Build Requirements for Vessel Documentation § 67.97 United States built. To be considered built in the United States a vessel must meet both of the following criteria: (a) All...

  18. 46 CFR 67.97 - United States built.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false United States built. 67.97 Section 67.97 Shipping COAST... DOCUMENTATION OF VESSELS Build Requirements for Vessel Documentation § 67.97 United States built. To be considered built in the United States a vessel must meet both of the following criteria: (a) All...

  19. 46 CFR 67.97 - United States built.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false United States built. 67.97 Section 67.97 Shipping COAST... DOCUMENTATION OF VESSELS Build Requirements for Vessel Documentation § 67.97 United States built. To be considered built in the United States a vessel must meet both of the following criteria: (a) All...

  20. 47 CFR 15.23 - Home-built devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Home-built devices. 15.23 Section 15.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.23 Home-built... constructed from a kit, and are built in quantities of five or less for personal use. (b) It is recognized...

  1. 47 CFR 15.23 - Home-built devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Home-built devices. 15.23 Section 15.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.23 Home-built... constructed from a kit, and are built in quantities of five or less for personal use. (b) It is recognized...

  2. 47 CFR 15.23 - Home-built devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Home-built devices. 15.23 Section 15.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES General § 15.23 Home-built... constructed from a kit, and are built in quantities of five or less for personal use. (b) It is recognized...

  3. The QUASAR facility

    NASA Astrophysics Data System (ADS)

    Gates, David

    2013-10-01

    The QUAsi-Axisymmetric Research (QUASAR) stellarator is a new facility which can solve two critical problems for fusion, disruptions and steady-state, and which provides new insights into the role of magnetic symmetry in plasma confinement. If constructed it will be the only quasi-axisymmetric stellarator in the world. The innovative principle of quasi-axisymmetry (QA) will be used in QUASAR to study how ``tokamak-like'' systems can be made: 1) Disruption-free, 2) Steady-state with low recirculating power, while preserving or improving upon features of axisymmetric tokamaks, such as 1) Stable at high pressure simultaneous with 2) High confinement (similar to tokamaks), and 3) Scalable to a compact reactor Stellarator research is critical to fusion research in order to establish the physics basis for a magnetic confinement device that can operate efficiently in steady-state, without disruptions at reactor-relevant parameters. The two large stellarator experiments - LHD in Japan and W7-X under construction in Germany are pioneering facilities capable of developing 3D physics understanding at large scale and for very long pulses. The QUASAR design is unique in being QA and optimized for confinement, stability, and moderate aspect ratio (4.5). It projects to a reactor with a major radius of ~8 m similar to advanced tokamak concepts. It is striking that (a) the EU DEMO is a pulsed (~2.5 hour) tokamak with major R ~ 9 m and (b) the ITER physics scenarios do not presume steady-state behavior. Accordingly, QUASAR fills a critical gap in the world stellarator program. This work supported by DoE Contract No. DEAC02-76CH03073.

  4. Hybrid heat exchange for the compression capture of CO2 from recirculated flue gas

    SciTech Connect

    Oryshchyn, Danylo B.; Ochs, Thomas L.; Summers, Cathy A.

    2004-01-01

    An approach proposed for removal of CO2 from flue gas cools and compresses a portion of a recirculated flue-gas stream, condensing its volatile materials for capture. Recirculating the flue gas concentrates SOx, H2O and CO2 while dramatically reducing N2 and NOx, enabling this approach, which uses readily available industrial components. A hybrid system of indirect and direct-contact heat exchange performs heat and mass transfer for pollutant removal and energy recovery. Computer modeling and experimentation combine to investigate the thermodynamics, heat and mass transfer, chemistry and engineering design of this integrated pollutant removal (IPR) system.

  5. Non-premixed conditions in the flameholding recirculation region behind a step in supersonic flow

    NASA Astrophysics Data System (ADS)

    Thakur, Amit

    Flameholding in supersonic flow depends on local conditions in the recirculation region, and on mass transfer into and out of this region. Large gradients in local gas composition and temperature exist in the recirculation region. Hence, stability parameter correlations developed for premixed flames cannot be used to determine blowout stability limits for non-premixed flames encountered in practical devices. In the present study, mixture samples were extracted at different locations in the recirculation region and the shear layer formed behind a rearward-facing step in supersonic flow, and analyzed by mass spectrometry to determine the species concentration distribution in the region. The point-wise mass spectrometer measurements were complemented by acetone planar laser-induced fluorescence (PLIF) measurements to get a planar distribution of fuel mole fraction in the recirculation region. Non-reacting flow tests and combustion experiments were performed by varying various fuel related parameters such as injection location, injection pressure and fuel type. Fuel injection upstream of the step was not effective in supplying enough fuel to the recirculation region and did not sustain the flame in combustion experiments. Fuel injection at the step base was effective in sustaining the flame. For base injection, the local fuel mole fraction in the recirculation region determined from experiments was an order of magnitude higher than the global fuel mole fraction based on total moles of air flowing through the test section and total fuel injected in the test section. This suggests substantial difference in flame stability curve for non-premixed conditions in the scramjet engine compared to premixed flow. For base injection, fuel remained in the recirculation region even at higher injection pressure. Due to slower diffusion rate, the heavier fuel had higher local mole fraction in the recirculation region compared to lighter fuel for a unit global fuel mole fraction

  6. Heat and mass transfer in turbulent flows with several recirculated flow eddies

    NASA Astrophysics Data System (ADS)

    Baake, E.; Nacke, B.; Jakovics, A.; Umbrashko, A.

    2001-06-01

    Numerical modeling of the concentration and temperature distribution in axial symmetrical systems with several recirculated flow eddies, which is based on various 2D stationary k-ɛ models and commercial codes, e.g. ANSYS and FLUENT, leads to results, which are significantly different from experimental data. Therefore additional user-defined subroutines were included in the commercial program code to improve the turbulent heat and mass transfer in the zone between the recirculated flow eddies. In addition transient 3D calculations were performed to investigate scientifically the flow dynamics. Figs 9, Refs 8.

  7. The crop growth research chamber: A ground-based facility for CELSS research

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.

    1990-01-01

    A ground based facility for the study of plant growth and development under stringently controlled environments is being developed by the Closed Ecological Life Support System (CELSS) program at the Ames Research Center. Several Crop Growth Research Chambers (CGRC) and laboratory support equipment provide the core of this facility. The CGRC is a closed (sealed) system with a separate recirculating atmosphere and nutrient delivery systems. The atmospheric environment, hydroponic environment, systems controls, and data acquisition are discussed.

  8. Exploring the Role of the Built and Social Neighborhood Environment in Moderating Stress and Health

    PubMed Central

    Yang, Tse-Chuan

    2014-01-01

    Background Health researchers have explored how different aspects of neighborhood characteristics contribute to health and well-being, but current understanding of built environment factors is limited. Purpose This study explores whether the association between stress and health varies by residential neighborhood, and if yes, whether built and social neighborhood environment characteristics act as moderators. Methods This study uses multilevel modeling and variables derived from geospatial data to explore the role of neighborhood environment in moderating the association of stress with health. Individual-level data (N=4,093) were drawn from residents of 45 neighborhoods within Philadelphia County, PA, collected as part of the 2006 Philadelphia Health Management Corporation's Household Health Survey. Results We find that the negative influence of high stress varied by neighborhood, that residential stability and affluence (social characteristics) attenuated the association of high stress with health, and that the presence of hazardous waste facilities (built environment characteristics) moderated health by enhancing the association with stress. Conclusions Our findings suggest that neighborhood environment has both direct and moderating associations with health, after adjusting for individual characteristics. The use of geospatial data could broaden the scope of stress–health research and advance knowledge by untangling the intertwined relationship between built and social environments, stress, and health. In particular, future studies should integrate built environment characteristics in health-related research; these characteristics are modifiable and can facilitate health promotion policies. PMID:20300905

  9. The effects of economic development and built environment on diabetes in CHINA.

    PubMed

    Zhang, Tao

    2017-09-29

    With rapid economy growth, the prevalence of obesity, and related chronic diseases, has increased greatly. Although this has been widely recognized, little attention has been paid to the influence of built environment and economic growth, particularly for developing countries. The main purpose of this study is to investigate the potential relationship between the prevalence of diabetes and the built environment while considering the effects of socioeconomic change in China. Three nationally representative samples are constructed and employed mainly based on various sources of data, such as the China National Nutrition and Health Survey, World Health Organization, and China Health and Retirement Longitudinal Survey in 2013. The explanatory variables representing the built environment and influential factors include the health outcomes, economic indicators, local health facilities, regional dummies, and demographic features. OLS, robust regressions, and a set of binary choice models are used to estimate the possible relationship. It is suggested that the prevalence of diabetes is associated with both the broader built environment and individual economic factors in China. China's sharp economic growth in the recent decades has greatly increased the prevalence of obesity and diabetes, when also considering other influential factors. Although the results can not specify causal mechanism, some useful results can be clearly discovered and subsequently a few important policy implications can be provided for the sustainable and healthy development of China's urban planning or built environment.

  10. Multilevel modelling of built environment characteristics related to neighbourhood walking activity in older adults

    PubMed Central

    Li, F.; Fisher, K; Brownson, R.; Bosworth, M.

    2005-01-01

    Objective: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. Design, setting, participants: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. Main outcome measure: Self reported neighbourhood walking. Main results: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. Conclusions: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences. PMID:15965138

  11. Use of a micro programmable logic controller for oxygen monitoring and control in multiple tanks of a recirculating aquaculture system

    USDA-ARS?s Scientific Manuscript database

    In intensive recirculating aquaculture systems the use of supplemental oxygen, specifically pure liquid oxygen, increases the mass of fish that can be supported and eliminates oxygen as a major limiting factor to a system’s carrying capacity. The use of pure oxygen in a recirculating aquaculture sys...

  12. An evaluation of a micro programmable logic controller for oxygen monitoring and control in tanks of a recirculating aquaculture system

    USDA-ARS?s Scientific Manuscript database

    Control of dissolved gases, especially oxygen is an essential component of recirculating aquaculture systems. The use of pure oxygen in a recirculating aquaculture system creates supersaturated concentrations of dissolved oxygen and can reduce fish production costs by supporting greater fish and fee...

  13. Molecular Rotors Built in Porous Materials.

    PubMed

    Comotti, Angiolina; Bracco, Silvia; Sozzani, Piero

    2016-09-20

    Molecules and materials can show dynamic structures in which the dominant mechanism is rotary motion. The single mobile elements are defined as "molecular rotors" and exhibit special properties (compared with their static counterparts), being able in perspective to greatly modulate the dielectric response and form the basis for molecular motors that are designed with the idea of making molecules perform a useful mechanical function. The construction of ordered rotary elements into a solid is a necessary feature for such design, because it enables the alignment of rotors and the fine-tuning of their steric and dipolar interactions. Crystal surfaces or bulk crystals are the most suitable to adapt rotors in 2D or 3D arrangements and engineer juxtaposition of the rotors in an ordered way. Nevertheless, it is only in recent times that materials showing porosity and remarkably low density have undergone tremendous development. The characteristics of large free volume combine well with the virtually unhindered motion of the molecular rotors built into their structure. Indeed, the molecular rotors are used as struts in porous covalent and supramolecular architectures, spanning both hybrid and fully organic materials. The modularity of the approach renders possible a variety of rotor geometrical arrangements in both robust frameworks stable up to 850 K and self-assembled molecular materials. A nanosecond (fast dynamics) motional regime can be achieved at temperatures lower than 240 K, enabling rotor arrays operating in the solid state even at low temperatures. Furthermore, in nanoporous materials, molecular rotors can interact with the diffusing chemical species, be they liquids, vapors, or gases. Through this chemical intervention, rotor speed can be modulated at will, enabling a new generation of rotor-containing materials sensitive to guests. In principle, an applied electric field can be the stimulus for chemical release from porous materials. The effort needed to

  14. 310 Facility chemical specifications

    SciTech Connect

    Hagerty, K.J.

    1997-05-21

    The 300 area Treated Effluent Disposal Facility (TEDF) was designed and built to treat the waste water from the 300 area process sewer system. Several treatment technologies are employed to remove the trace quantities of contaminants in the stream, including iron coprecipitation, clarification, filtration, ion exchange, and ultra violet light/hydrogen peroxide oxidation of organics. The chemicals that will be utilized in the treatment process are hydrogen peroxide, sulfuric acid, sodium hydroxide, and ferric chloride. This document annotates the required chemical characteristics of TEDF bulk chemicals as well as the criteria that were used to establish these criteria. The chemical specifications in appendix B are generated from this information.

  15. Improvement of anaerobic digester performance by wastewater recirculation through an aerated membrane.

    USDA-ARS?s Scientific Manuscript database

    Swine wastewater from an anaerobic digester was recirculated through a silicone hose located in an external aeration chamber to determine its effect on wastewater malodorants and biogas composition. The silicone hose acted as a semipermeable membrane for the passage of small molecules. In the first...

  16. Solids removal from a coldwater recirculating system - comparison of swirl separator and radial-flow settlers

    USDA-ARS?s Scientific Manuscript database

    Solids removal across two settling devices, i.e., a swirl separator and a radial-flow settler, and across a microscreen drum filter was evaluated in a fully recirculating system containing a single 150 m3 'Cornell-type' dual-drain tank during the production of food-size Arctic char and rainbow trout...

  17. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  18. The benefits of powdered activated carbon recirculation for micropollutant removal in advanced wastewater treatment.

    PubMed

    Meinel, F; Zietzschmann, F; Ruhl, A S; Sperlich, A; Jekel, M

    2016-03-15

    PAC adsorption is a widespread option for the removal of organic micropollutants (OMP) from secondary effluent. For an optimal exploitation of the adsorption capacity, PAC recirculation is nowadays a common practice, although the mechanistic interrelations of the complex recirculation process are not fully resolved. In this work, extensive multi-stage batch adsorption testing with repeated PAC and coagulant dosage was performed to evaluate the continuous-flow recirculation system. Partly loaded PAC showed a distinct amount of remaining capacity, as OMP and DOC removals considerably increased with each additional adsorption stage. At a low PAC dose of 10 mg PAC L(-1), removals of benzotriazole and carbamazepine were shown to rise from <40% in the first stage up to >80% in the 11th stage at 30 min adsorption time per stage. At a high PAC dose of 30 mg PAC L(-1), OMP and DOC removals were significantly higher and reached 98% (for benzotriazole and carbamazepine) after 11 stages. Coagulant dosage showed no influence on OMP removal, whereas a major part of DOC removal can be attributed to coagulation. Multi-stage adsorption is particularly beneficial for small PAC doses and significant PAC savings are feasible. A new model approach for predicting multi-stage OMP adsorption on the basis of a single-stage adsorption experiment was developed. It proved to predict OMP removals and PAC loadings accurately and thus contributes towards understanding the PAC recirculation process.

  19. Confined turbulent swirling recirculating flow predictions. Ph.D. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Abujelala, M. T.; Lilley, D. G.

    1985-01-01

    The capability and the accuracy of the STARPIC computer code in predicting confined turbulent swirling recirculating flows is presented. Inlet flow boundary conditions were demonstrated to be extremely important in simulating a flowfield via numerical calculations. The degree of swirl strength and expansion ratio have strong effects on the characteristics of swirling flow. In a nonswirling flow, a large corner recirculation zone exists in the flowfield with an expansion ratio greater than one. However, as the degree of inlet swirl increases, the size of this zone decreases and a central recirculation zone appears near the inlet. Generally, the size of the central zone increased with swirl strength and expansion ratio. Neither the standard k-epsilon turbulence mode nor its previous extensions show effective capability for predicting confined turbulent swirling recirculating flows. However, either reduced optimum values of three parameters in the mode or the empirical C sub mu formulation obtained via careful analysis of available turbulence measurements, can provide more acceptable accuracy in the prediction of these swirling flows.

  20. CCR7 Controls Thymus Recirculation, but Not Production and Emigration, of Foxp3(+) T Cells.

    PubMed

    Cowan, Jennifer E; McCarthy, Nicholas I; Anderson, Graham

    2016-02-09

    Current models of Foxp3(+) regulatory T cell (Treg) development involve CCR7-mediated migration of thymocytes into the thymus medulla to enable essential interactions with medullary epithelium. However, increased Foxp3(+) thymic Treg numbers in Ccr7(-/-) mice challenge this view, and the role of CCR7 in Treg development, emigration, and/or recirculation is unknown. Here, we have examined CCR7 and Rag2pGFP levels during Treg development and generated Rag2pGFPCcr7(-/-) mice to study its impact on the intrathymic Treg pool. We reveal surprising developmental heterogeneity in thymocytes described as Treg precursors, showing that they contain recirculating CCR6(+)CCR7(-)Rag2pGFP(-) T cells. Although CCR7 defines bona fide Rag2GFP(+) Treg precursors, it is not required for Treg production and emigration. Rather, we show that lack of CCR7 renders the thymus more receptive to Treg thymus homing. Our study reveals a role for CCR7 in limiting Treg recirculation back to the thymus and enables separation of the mechanisms controlling Treg production and thymic recirculation.

  1. Achromatic recirculated chicane with fixed geometry and independently variable path length and momentum compaction

    DOEpatents

    Douglas, David R.; Neil, George R.

    2005-04-26

    A particle beam recirculated chicane geometry that, through the inducement of a pair of 180 degree bends directed by the poles of a pair of controllable magnetic fields allows for variation of dipole position, return loop radii and steering/focussing, thereby allowing the implementation of independent variation of path length and momentum compaction.

  2. Vortex formation and recirculation zones in left anterior descending artery stenoses: computational fluid dynamics analysis

    NASA Astrophysics Data System (ADS)

    Katritsis, D. G.; Theodorakakos, A.; Pantos, I.; Andriotis, A.; Efstathopoulos, E. P.; Siontis, G.; Karcanias, N.; Redwood, S.; Gavaises, M.

    2010-03-01

    Flow patterns may affect the potential of thrombus formation following plaque rupture. Computational fluid dynamics (CFD) were employed to assess hemodynamic conditions, and particularly flow recirculation and vortex formation in reconstructed arterial models associated with ST-elevation myocardial infraction (STEMI) or stable coronary stenosis (SCS) in the left anterior descending coronary artery (LAD). Results indicate that in the arterial models associated with STEMI, a 50% diameter stenosis immediately before or after a bifurcation creates a recirculation zone and vortex formation at the orifice of the bifurcation branch, for most of the cardiac cycle, thus allowing the creation of stagnating flow. These flow patterns are not seen in the SCS model with an identical stenosis. Post-stenotic recirculation in the presence of a 90% stenosis was evident at both the STEMI and SCS models. The presence of 90% diameter stenosis resulted in flow reduction in the LAD of 51.5% and 35.9% in the STEMI models and 37.6% in the SCS model, for a 10 mmHg pressure drop. CFD simulations in a reconstructed model of stenotic LAD segments indicate that specific anatomic characteristics create zones of vortices and flow recirculation that promote thrombus formation and potentially myocardial infarction.

  3. Performance of two-stage vegetable waste anaerobic digestion depending on varying recirculation rates.

    PubMed

    Zuo, Zhuang; Wu, Shubiao; Zhang, Wanqin; Dong, Renjie

    2014-06-01

    Vegetable waste, which characterized by high moisture content, was evaluated as a substrate for biogas production. The effects of recirculation rate (RR) on the performance of two-stage anaerobic digestion were investigated. The system was operated at an organic loading rate of 1.7 g VS/L/d with varying RRs (0, 0.6, 1, and 1.4). Results demonstrated that volumetric biogas production rates in acidogenic reactor increased from approximately 0.2 7 L/L/d to 0.97 L/L/d, when pH is increased from approximately 5.1 to 6.7. These indicate that recirculation of alkaline effluent from the methanogenic reactor helps create a favorable condition for biogas production in the acidogenic reactor. The decrease in chemical oxygen demand (COD) concentrations from approximately 21,000 mg/L to 6800 mg/L was also observed in the acidogenic reactor. This condition may be attributed to dilution under recirculation. The dynamics between hydrolysis and methanogenesis under recirculation indicated that mass transfer capacity between two-stage reactors improved.

  4. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    EPA Science Inventory

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  5. Building America Case Study: Control Retrofits for Multifamily Domestic Hot Water Recirculation Systems, Brooklyn, New York

    SciTech Connect

    2016-12-01

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7 percent after implementing the demand control technique, 2 percent after implementing temperature modulation, and 15 percent after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8 percent, 1 percent, and 14 percent for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  6. Building America Case Study: Control Retrofits for Multifamily Domestic Hot Water Recirculation Systems, Brooklyn, New York

    SciTech Connect

    J. Dentz; E. Ansanelli, H. Henderson, Jr.; K. Varshney

    2016-12-01

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  7. Pilot-scale study of powdered activated carbon recirculation for micropollutant removal.

    PubMed

    Meinel, F; Sperlich, A; Jekel, M

    Adsorption onto powdered activated carbon (PAC) is a promising technique for the removal of organic micropollutants (OMPs) from treated wastewater. To enhance the adsorption efficiency, PAC is recycled back into the adsorption stage. This technique was examined in pilot scale in comparison to a reference without recirculation. Coagulation with Fe(3+) was carried out simultaneously to adsorption. Extensive OMP measurements showed that recirculation significantly increased OMP eliminations. Thus, significant PAC savings were feasible. The PAC concentration in the contact reactor proved to be an important operating parameter that can be surrogated by the easily measurable total suspended solids (TSS) concentration. OMP eliminations increased with increasing TSS concentrations. At 20 mg PAC L(-1) and 2.8 g TSS L(-1) in the contact reactor, well-adsorbable carbamazepine was eliminated by 97%, moderately adsorbable diclofenac was eliminated by 92% and poorly-adsorbable acesulfame was eliminated by 54% in comparison to 49%, 35% and 18%, respectively, without recirculation. The recirculation system represents an efficient technique, as the PAC's adsorption capacity is practically completely used. Small PAC dosages yield high OMP eliminations. Poorly-adsorbable gabapentin was eliminated to an unexpectedly high degree. A laboratory-scale biomass inhibition study showed that aerobic biodegradation removed gabapentin in addition to adsorption.

  8. Nitrate removal effectiveness of fluidized sulfur-based autotrophic denitrification biofilters for recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    There is a need to develop practical methods to reduce nitrate -nitrogen loads from recirculating aqua-culture systems to facilitate increased food protein production simultaneously with attainment of water quality goals. The most common wastewater denitrification treatment systems utilize methanol-...

  9. Suction-recirculation device for stabilizing particle flows within a solar powered solid particle receiver

    DOEpatents

    Kolb, Gregory J [Albuquerque, NM

    2012-02-07

    A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained. Suction-recirculation velocities in the range of 1-5 m/s are sufficient to stabilize the particle curtain against external wind speeds in excess of 10 m/s.

  10. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    The “earthy” and “muddy” off-flavors in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol (MIB) in the flesh of the fish. Similar off-flavors have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the ...

  11. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    EPA Science Inventory

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  12. Removal of Nutrients from Septic Effluent with Re-circulated Hybrid Tidal Flow Constructed Wetland

    Treesearch

    Lihua Cui; Jigkun Feng; Ying Ouyang; Peiwen. Deng

    2012-01-01

    Hybrid tidal flow constructed wetland (CW) with recirculation is an improved biological and engineering technique for removal of excess nutrients and certain pollutants from wastewater. This study investigated the removal efficiency of total phosphorus (TP), ammonia-nitrogen (NH3-N), and total nitrogen (TN) from septic tank effluent with the hybrid tidal flow CW system...

  13. Experimental investigation of a local recirculation photobioreactor for mass cultures of photosynthetic microorganisms.

    PubMed

    Moroni, Monica; Cicci, Agnese; Bravi, Marco

    2014-04-01

    The present work deals with the experimental fluid mechanics analysis of a wavy-bottomed cascade photobioreactor, to characterize the extent and period of recirculatory and straight-flowing streams establishing therein as a function of reactor inclination and liquid flow rate. The substream characterization via Feature Tracking (FT) showed that a local recirculation zone establishes in each vane only at inclinations ≤6° and that its location changes from the lower (≤3°) to the upper part of each vane (6°). A straight-flowing stream flows opposite (above or below) the local recirculation stream. The recirculation time ranges from 0.86 s to 0.23 s, corresponding, respectively, to the minimum flow rate at the minimum inclination and to the maximum flow rate at the maximum inclination where recirculation was observed. The increase of photosynthetic activity, resulting from the entailed "flash effect", was estimated to range between 102 and 113% with respect to equivalent tubular and bubble column photobioreactors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Multi-point optimization of recirculation flow type casing treatment in centrifugal compressors

    NASA Astrophysics Data System (ADS)

    Tun, Min Thaw; Sakaguchi, Daisaku

    2016-06-01

    High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines. A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal compressors. Two ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. The shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from ANSYS. The numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate range. Sensitivity analysis of design parameters as a function of efficiency has been performed. It is found that the optimized casing design provides optimized recirculation flow rate, in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.

  15. Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation

    USDA-ARS?s Scientific Manuscript database

    Airlifts simplify recirculating aquaculture systems and can potentially reduce capital costs and minimize maintenance issues. Airlifts have the ability to move and aerate water as well as degass the water of any carbon dioxide. This study evaluated the oxygen transfer and carbon dioxide removal abil...

  16. Evaluation of commercial marine fish feeds for production of juvenile cobia in recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...

  17. Disinfection of water in recirculating aquaculture systems with peracetic acid (PAA)

    USDA-ARS?s Scientific Manuscript database

    The disinfection behaviour of peracetic acid (PAA) in recirculating aquaculture systems (RAS) was investigated. Peracetic acid is a strong oxidizing agent found in various concentrations in different products. Three Wofasteril PAA products (E400 (c), Lspecical; AC 150) were tested in vitro for the...

  18. Researchers evaluate low-energy recirculating system for inland production of marine finfish juveniles

    USDA-ARS?s Scientific Manuscript database

    The low-energy recirculating aquaculture system consists of nine separate modules which utilize the double drain fish culture tank paired to a moving bed biofilter. The nine fiberglass tanks are five feet in diameter and normal water depth is about three feet for a total tank volume of approximately...

  19. Low-head recirculating aquaculture system for juvenile red drum production

    USDA-ARS?s Scientific Manuscript database

    The USDA Agricultural Research Service and the Center for Aquaculture and Stock Enhancement at Harbor Branch Oceanographic Institute-FAU (HBOI-FAU) are collaborating to evaluate low-head recirculating aquaculture system designs to intensively produce red drum juveniles as part of the Florida Fish an...

  20. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    The aim of the present work was to simulate water treatment practice with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1700 L pilot scale RAS were divided into two experimental groups based on daily feed allocation and were operated under constant conditions durin...

  1. Simulation studies of a XUV/soft X-ray harmonic-cascade FEL for the proposed LBNL recirculating linac*

    SciTech Connect

    Fawley, W.M.; Barletta, W.A.; Corlett, J.N.; Zholents, A.

    2003-06-02

    Presently there is significant interest at LBNL in designing and building a facility for ultrafast (i.e. femtosecond time scale) x-ray science based upon a superconducting, recirculating RF linac (see Corlett et al. for more details). In addition to producing synchrotron radiation pulses in the 1-15 keV energy range, we are also considering adding one or more free-electron laser (FEL) beamlines using a harmonic cascade approach to produce coherent XUV soft X-ray emission beginning with a strong input seed at {approx}200 nm wavelength obtained from a ''conventional'' laser. Each cascade is composed of a radiator together with a modulator section, separated by a magnetic chicane. The chicane temporally delays the electron beam pulse in order that a ''virgin'' pulse region (with undegraded energy spread) be brought into synchronism with the radiation pulse, which together then undergo FEL action in the modulator. We present various results obtained with the GINGER simulation code examining final output sensitivity to initial electron beam parameters. We also discuss the effects of spontaneous emission and shot noise upon this particular cascade approach which can limit the final output coherence.

  2. Back to the Roots: The Integration of a Constructed Wetland into a Recirculating Hatchery - A Case Study

    PubMed Central

    Buřič, Miloš; Bláhovec, Josef; Kouřil, Jan

    2015-01-01

    Aquaculture is currently one of the fastest growing food-producing sectors, accounting for around 50% of the world's food fish. Limited resources, together with climatic change, have stimulated the search for solutions to support and sustain the production of fish as a nutritious food. The integration of a constructed wetland (CW) into a recirculating hatchery (RHS) was evaluated with respect to its economic feasibility and environmental impact. The outcome of eight production cycles showed the potential of CW integration for expanded production without increased operation costs or environmental load. Concretely, the use of constructed wetland allows the rearing about 40% more fish biomass, resulting in higher production and profitability. The low requirements for space, fresh water, and energy enable the establishment of such systems almost anywhere. Constructed wetlands could enhance the productivity of existing small scale facilities, as well as larger systems, to address economic and environmental issues in aquaculture. Such systems have potential to be sustainable in the context of possible future climate change and resource limitations. PMID:25853416

  3. Back to the roots: the integration of a constructed wetland into a recirculating hatchery - a case study.

    PubMed

    Buřič, Miloš; Bláhovec, Josef; Kouřil, Jan

    2015-01-01

    Aquaculture is currently one of the fastest growing food-producing sectors, accounting for around 50% of the world's food fish. Limited resources, together with climatic change, have stimulated the search for solutions to support and sustain the production of fish as a nutritious food. The integration of a constructed wetland (CW) into a recirculating hatchery (RHS) was evaluated with respect to its economic feasibility and environmental impact. The outcome of eight production cycles showed the potential of CW integration for expanded production without increased operation costs or environmental load. Concretely, the use of constructed wetland allows the rearing about 40% more fish biomass, resulting in higher production and profitability. The low requirements for space, fresh water, and energy enable the establishment of such systems almost anywhere. Constructed wetlands could enhance the productivity of existing small scale facilities, as well as larger systems, to address economic and environmental issues in aquaculture. Such systems have potential to be sustainable in the context of possible future climate change and resource limitations.

  4. Recirculation zone dynamics of a transversely excited swirl flow and flame

    NASA Astrophysics Data System (ADS)

    O'Connor, Jacqueline; Lieuwen, Tim

    2012-07-01

    This work investigates the response of the vortex breakdown region of a swirling, annular jet to transverse acoustic excitation for both non-reacting and reacting flows. This swirling flow field consists of a central vortex breakdown region, two shear layers, and an annular fluid jet. The vortex breakdown bubble, a region of highly turbulent recirculating flow in the center of the flowfield, is the result of a global instability of the swirling jet. Additionally, the two shear layers originating from the inner and outer edge of the annular nozzle are convectively unstable and rollup due to the Kelvin-Helmholtz instability. Unlike the convectively unstable shear layers that respond in a monotonic manner to acoustic forcing, the recirculation zone exhibits a range of response characteristics, ranging from minimal response to exhibiting abrupt bifurcations at large forcing amplitudes. In this study, the response of the time-average and fluctuating recirculation zone is measured as a function of forcing frequency, amplitude, and symmetry. The time-average flow field is shown to exhibit both monotonically varying and abrupt bifurcation features as acoustic forcing amplitude is increased. The unsteady motion in the recirculation zone is dominated by the low frequency precession of the vortex breakdown bubble. In the unforced flow, the azimuthal m = -2 and m = -1 modes (i.e., disturbances rotating in the same direction as the swirl flow) dominate the velocity disturbance field. These modes correspond to large scale deformation of the jet column and two small-scale precessing vortical structures in the recirculation zone, respectively. The presence of high amplitude acoustic forcing changes the relative amplitude of these two modes, as well as the character of the self-excited motion. For the reacting flow problem, we argue that the direct effect of these recirculation zone fluctuations on the flame response to flow forcing is not significant. Rather, flame wrinkling in

  5. Re-circulation artefact at the carotid bulb can be differentiated from true stenosis.

    PubMed

    Ahn, K J; You, W J; Lee, J H; Kang, B J; Kim, Y J; Kim, B S; Hahn, S T

    2004-07-01

    Re-circulation artefact developing secondary to vortex flow at the bulb of the internal carotid artery is very difficult to distinguish from true stenotic defect on two-dimensional Fourier transformed time-of-flight magnetic resonance angiography (2D-FT TOF MRA). The purpose of our study is to identify appropriate distinguishing features of re-circulation artefact. We included 45 extracranial carotid arteries collected from 25 patients who underwent both 2D-FT TOF MRA and contrast medium based angiography. Review of the 45 vessels demonstrated re-circulation artefact in 21 vessels, true stenotic defect in 8 vessels, and no filling defect in 16 vessels on 2D-FT TOF MRA. We compared the findings of re-circulation artefact and true stenotic defect in 29 vessels excluding the 16 vessels without filling defect. The following were evaluated: (1) preservation of posterior wall contour; (2) marginal character of filling defect; (3) darkness of filling defect; (4) involvement of common carotid artery by filling defect; (5) size of filling defect. In four out of the five evaluated items, statistically significant difference was present between re-circulation artefact group and true stenotic defect group (p<0.01 in all four items, chi(2) analysis). Re-circulation artefact demonstrated the preservation of the posterior wall contour (19/21), ill-defined margin (19/21), less dark defect (18/21), and no involvement of the common carotid artery (19/21). On the contrary true stenotic defect demonstrated focal loss of posterior wall contour (8/8), sharp margin (8/8), dark defect (8/8), and involvement of common carotid artery (4/8). No significant difference was noted in the size of the defect between the two groups (p>0.05). The specificity of 2D-FT TOF MRA for carotid stenosis was markedly increased after application of above signs. These distinguishing signs are very helpful in differentiating re-circulation artefact from true stenotic defect.

  6. Using Built Environmental Observation Tools: Comparing Two Methods of Creating a Measure of the Built Environment

    PubMed Central

    Keast, Erin M.; Carlson, Nichole E.; Chapman, Nancy J.; Michael, Yvonne L.

    2011-01-01

    Purpose Identify an efficient method of creating a comprehensive and concise measure of the built environment integrating data from geographic information systems (GIS) and the Senior Walking Environmental Assessment Tool (SWEAT). Design Cross-sectional study using a population sample. Setting Eight municipally defined neighborhoods in Portland, Oregon. Subjects Adult residents (N = 120) of audited segments (N = 363). Measures We described built environmental features using SWEAT audits and GIS data. We obtained information on walking behaviors and potential confounders through in-person interviews. Analysis We created two sets of environviental measures, one based on the conceptual framework used to develop SWEAT and another using principal component analysis (PCA). Each measure’s association with walking for transportation and exercise was then assessed and compared using logistic regression. Results A priori measures (destinations, safety, aesthetics, and functionality) and PCA measures (accessibility, comfort/safety, maintenance, and pleasantness) were analogous in conceptual meaning and had similar associations with walking. Walking for transportation was associated with destination accessibility and functional elements, whereas walking for exercise was associated with maintenance of the walking area and protection from traffic. However, only PCA measures consistently reached statistical significance. Conclusion The measures created with PCA were more parsimonious than those created a priori. Performing PCA is an efficient method of combining and scoring SWEAT and GIS data. PMID:20465151

  7. A technique for the assessment of the visual impact of nearshore confined dredged materials and other built islands

    Treesearch

    Roy Mann

    1979-01-01

    Drilling rigs, confined dredged material disposal sites power and sewage treatment facilities, and other built objects on or near shorelines have often created appreciable impacts on the aesthetic perceptions of residents and recreational users. Techniques for assessing such impacts that are reviewed in this paper include viewscape analysis for large-scale shore...

  8. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  9. Performance of Water Recirculation Loop Maintentance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  10. Full-scale leachate-recirculating MSW landfill bioreactor assessments

    SciTech Connect

    Carson, D.A.

    1995-10-01

    The integrated waste management hierarchy philosophy continues to develop as a useful tool to solve solid waste issues in an environmentally responsible manner. Recent statistics indicate that approximately two thirds of municipal solid waste in the United States is disposed in landfills. Current landfill operational technique involves the preparation of a waste containment facility, the filling of the waste unit, installation of the final cover, and the maintenance of the unit. This method of operation has proven to be reasonably effective in waste disposal, effectively minimizing risk by collecting the liquid that percolates through the waste, called leachates, at the bottom of the landfill, and controlling landfill gas with collection systems. Concerns over the longevity of containment systems components present questions that cannot be answered without substantial performance data. Landfills, as currently operated, serve to entomb dry waste. Therefore, the facility must be maintained in perpetuity, consuming funds and ultimately driving up waste collection costs. This presentation will describe a new form of solid waste landfill operation, it is a technique that involves controlled natural processes to break down landfilled waste, and further minimize risk to human health and the environment. A landfill operated in an active manner will encourage and control natural decomposition of landfilled waste. This can be accomplished by collecting leachate, and reinjecting it into the landfilled waste mass. Keeping the waste mass moist will lead to a largely anaerobic system with the capacity to rapidly stabilize the landfilled waste mass via physical, chemical and biological methods. The system has proven the ability to breakdown portions of the waste mass, and to degrade toxic materials at the laboratory scale.

  11. Engine Air Intake Manifold Having Built In Intercooler

    DOEpatents

    Freese, V, Charles E.

    2000-09-12

    A turbocharged V type engine can be equipped with an exhaust gas recirculation cooler integrated into the intake manifold, so as to achieve efficiency, cost reductions and space economization improvements. The cooler can take the form of a tube-shell heat exchanger that utilizes a cylindrical chamber in the air intake manifold as the heat exchanger housing. The intake manifold depends into the central space formed by the two banks of cylinders on the V type engine, such that the central space is effectively utilized for containing the manifold and cooler.

  12. Life Cycle Assessment of LEED versus Conventionally Built Residential Units

    DTIC Science & Technology

    2011-03-24

    construction documents, a hybrid LCA was used to quantify and compare the environmental impact of energy efficient homes built at Keesler AFB to... construction documents, the hybrid LCA was used to quantify and compare the environmental impact of energy efficient homes built at 12 Keesler AFB to...conventionally built homes, this study employed a hybrid LCA and energy simulation. These energy efficient homes have a 16% less environmental impact

  13. 5. Conveyors 'C' through 'K' (built 1940) south of Station, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Conveyors 'C' through 'K' (built 1940) south of Station, looking northeast from hurricane barrier. - Manchester Street Generating Station, Conveyors, 460 Eddy Street, Providence, Providence County, RI

  14. The Use of Exhaust Gas Recirculation to Optimize Fuel Economy and Minimize Emission in Engines Operating on E85 Fuel

    SciTech Connect

    Wu, Ko-Jen

    2011-12-31

    This report summarizes activities conducted for the project “The Use of Exhaust Gas Recirculation to Optimized Fuel Economy and Minimize Emissions in Engines Operating on E85 Fuel” under COOPERATIVE AGREEMENT NUMBER DE-FC26-07NT43271, which are as outlined in the STATEMENT OF PROJECT OBJECTIVES (SOPO) dated March 2007 and in the supplemental SOPO dated October 2010. The project objective was to develop and demonstrate an internal combustion engine that is optimized for E85 (85% ethanol and 15% gasoline) fuel operation to achieve substantially improved fuel economy while operating with E85 fuel and that is also production viable in the near- to medium-term. The key engine technology selected for research and development was turbocharging, which is known to improve fuel economy thru downsizing and is in particular capable of exploiting ethanol fuel’s characteristics of high octane number and high latent heat of vaporization. The engine further integrated synergistic efficiency improving technologies of cooled exhaust gas recirculation (EGR), direct fuel injection and dual continuously variable intake and exhaust cam phasers. On the vehicle level, fuel economy was furthered thru powertrain system optimization by mating a state-of-the-art six-speed automatic transmission to the engine. In order to achieve the project’s objective of near- to medium-term production viability, it was essential to develop the engine to be flex-fuel capable of operating with fuels ranging from E0 (0% ethanol and 100% gasoline) to E85 and to use three-way type of catalyst technology for exhaust aftertreatment. Within these scopes, various technologies were developed through systems approach to focus on ways to help accelerate catalyst light-off. Significant amount of development took place during the course of the project within General Motors, LLC. Many prototype flex-fuel engines were designed, built and developed with various hardware configurations selected to achieve the project

  15. Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells

    PubMed Central

    Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Campbell, Laura; Teague, Jessica E.; Schlapbach, Christoph; Elco, Christopher; Huang, Victor; Matos, Tiago R.; Kupper, Thomas S.; Clark, Rachael A.

    2015-01-01

    The skin of an adult human contains approximately 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All non-recirculating resident memory T cells (TRM) expressed CD69, but the majority were CD4+, CD103− and located in the dermis, in contrast to studies in mice. Both CD4+ and CD8+ CD103+ TRM were enriched in the epidermis, had potent effector functions and had a limited proliferative capacity compared to CD103− TRM. TRM of both types had more potent effector functions than recirculating T cells. Induction of CD103 on human T cells was enhanced by keratinocyte contact, depended on TGFβ and was independent of T cell keratinocyte adhesive interactions. We observed two distinct populations of recirculating T cells, CCR7+/L-selectin+ central memory T cells (TCM) and CCR7+/L-selectin− T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions and TMM were depleted more slowly from skin after alemtuzumab, suggesting TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. PMID:25787765

  16. Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor

    NASA Astrophysics Data System (ADS)

    Gancedo, Matthieu

    Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred

  17. Built-up Land Expansion in Urban China

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Chen, Zhigang; Huang, Xianjin

    2017-04-01

    Since the implementation of the reform and opening-up, rapid expansion of built-up land has caused a rapid reduction of arable land. The Ministry of Land and Resources of the People' s Republic of China has strengthened the management of built-up land through the basic arable land protection and the quota allocation of built-up land to control the urban sprawl. In addition, the general land use planning and the annual land use plan have been used to further ensure the effectiveness of land use management and control. However, the trend of built-up land expansion has not been effectively restrained. The built-up land expansion increased from 31.92 × 106 hm2 in 2005 to 38.89 × 106 hm2 in 2012. The rapid expansion of built-up land has been the major feature of land use changes in China and has led to built-up land vacancy and inefficient land use. This paper used a Data Envelopment Analysis (DEA) model to analyze the changes in built-up land efficiency in 336 cities in China from 2005 to 2012 during the implementation of National General Land Use Plan (2006-2020) (NGLUP). The results showed that the built-up land input-output efficiency of most cities declined, and more than half of the cities had excessive inputs of built-up land. Even in the most developed region of China, the built-up land efficiency was relatively low. The paper argues that the NGLUP failed to control the expansion of built-up land and to promote intensive land use. The allocation of built-up land designated by the Plan was not reasonable, and economic development has greatly relied on land inputs, which need to be improved. The paper finally suggests that the built-up land indices should be appropriately directed toward economically underdeveloped regions in central and western China, and the establishment of a withdrawal mechanism for inefficient land would better promote the efficient allocation of built-up land.

  18. Developing Best Practices for Capturing As-Built Building Information Models (BIM) for Existing Facilities

    DTIC Science & Technology

    2010-08-01

    allowing for the import of 2D drawings to use as an underlay when creating 3D geometry. SketchUp also supported a direct export into Google Earth. The...essentially a 3D modeler that creates 2D polygons. These 2D polygons that are generated can result in many inaccuracies if using the model to calculate...Earth, three-dimensional Portable Document Format ( 3D PDF), and BIM integration technologies, with a focus on task-centered interface and workflows

  19. Impact of nitrate-enhanced leachate recirculation on gaseous releases from a landfill bioreactor cell

    SciTech Connect

    Tallec, G.; Bureau, C.; Peu, P.; Benoist, J.C.; Lemunier, M.; Budka, A.; Presse, D.; Bouchez, T.

    2009-07-15

    This study evaluates the impact of nitrate injection on a full scale landfill bioreactor through the monitoring of gaseous releases and particularly N{sub 2}O emissions. During several weeks, we monitored gas concentrations in the landfill gas collection system as well as surface gas releases with a series of seven static chambers. These devices were directly connected to a gas chromatograph coupled to a flame ionisation detector and an electron capture detector (GC-FID/ECD) placed directly on the field. Measurements were performed before, during and after recirculation of raw leachate and nitrate-enhanced leachate. Raw leachate recirculation did not have a significant effect on the biogas concentrations (CO{sub 2}, CH{sub 4} and N{sub 2}O) in the gas extraction network. However, nitrate-enhanced leachate recirculation induced a marked increase of the N{sub 2}O concentrations in the gas collected from the recirculation trench (100-fold increase from 0.2 ppm to 23 ppm). In the common gas collection system however, this N{sub 2}O increase was no more detectable because of dilution by gas coming from other cells or ambient air intrusion. Surface releases through the temporary cover were characterized by a large spatial and temporal variability. One automated chamber gave limited standard errors over each experimental period for N{sub 2}O releases: 8.1 {+-} 0.16 mg m{sup -2} d{sup -1} (n = 384), 4.2 {+-} 0.14 mg m{sup -2} d{sup -1} (n = 132) and 1.9 {+-} 0.10 mg m{sup -2} d{sup -1} (n = 49), during, after raw leachate and nitrate-enhanced leachate recirculation, respectively. No clear correlation between N{sub 2}O gaseous surface releases and recirculation events were evidenced. Estimated N{sub 2}O fluxes remained in the lower range of what is reported in the literature for landfill covers, even after nitrate injection.

  20. Identifying built environmental patterns using cluster analysis and GIS: Relationships with walking, cycling and body mass index in French adults

    PubMed Central

    2012-01-01

    Background Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. Methods We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Results Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high

  1. Identifying built environmental patterns using cluster analysis and GIS: relationships with walking, cycling and body mass index in French adults.

    PubMed

    Charreire, Hélène; Weber, Christiane; Chaix, Basile; Salze, Paul; Casey, Romain; Banos, Arnaud; Badariotti, Dominique; Kesse-Guyot, Emmanuelle; Hercberg, Serge; Simon, Chantal; Oppert, Jean-Michel

    2012-05-23

    Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high accessibility to green areas and local

  2. The built environment and alcohol consumption in urban neighborhoods.

    PubMed

    Bernstein, Kyle T; Galea, Sandro; Ahern, Jennifer; Tracy, Melissa; Vlahov, David

    2007-12-01

    To examine the relations between characteristics of the neighborhood built environment and recent alcohol use. We recruited participants through a random digit dial telephone survey of New York City (NYC) residents. Alcohol consumption was assessed using a structured interview. All respondents were assigned to neighborhood of residence. Data on the internal and external built environment in 59 NYC neighborhoods were collected from archival sources. Multilevel models were used to assess the adjusted relations between features of the built environment and alcohol use. Of the 1355 respondents, 40% reported any alcohol consumption in the past 30 days, and 3% reported more than five drinks in one sitting (heavy drinking) in the past 30 days. Few characteristics of the built environment were associated with any alcohol use in the past 30 days. However, several features of the internal and external built environment were associated with recent heavy drinking. After adjustment, persons living in neighborhoods characterized by poorer features of the built environment were up to 150% more likely to report heavy drinking in the last 30 days compared to persons living in neighborhoods characterized by a better built environment. Quality of the neighborhood built environment may be associated with heavy alcohol consumption in urban populations, independent of individual characteristics. The role of the residential environment as a determinant of alcohol abuse warrants further examination.

  3. 12. Ore unloading dock, looking south. Dock, built in 1908, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Ore unloading dock, looking south. Dock, built in 1908, featured two 10-ton-capacity Hulett unloaders (shown here) built by the Wellman-Seaver-Morgan Co. of Cleveland. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  4. Transformative Learning: Innovating Sustainability Education in Built Environment

    ERIC Educational Resources Information Center

    Iyer-Raniga, Usha; Andamon, Mary Myla

    2016-01-01

    Purpose: This paper aims to evaluate how transformative learning is key to innovating sustainability education in the built environment in the region's universities, in addition to reporting on the research project undertaken to integrate sustainability thinking and practice into engineering/built environment curricula in Asia-Pacific…

  5. 49 CFR 41.117 - Buildings built with Federal assistance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Buildings built with Federal assistance. 41.117 Section 41.117 Transportation Office of the Secretary of Transportation SEISMIC SAFETY § 41.117 Buildings built with Federal assistance. (a) Each DOT Operating Administration assisting in the financing, through Federal grants or loans, or...

  6. 49 CFR 41.117 - Buildings built with Federal assistance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Buildings built with Federal assistance. 41.117 Section 41.117 Transportation Office of the Secretary of Transportation SEISMIC SAFETY § 41.117 Buildings built with Federal assistance. (a) Each DOT Operating Administration assisting in the financing, through...

  7. Transformative Learning: Innovating Sustainability Education in Built Environment

    ERIC Educational Resources Information Center

    Iyer-Raniga, Usha; Andamon, Mary Myla

    2016-01-01

    Purpose: This paper aims to evaluate how transformative learning is key to innovating sustainability education in the built environment in the region's universities, in addition to reporting on the research project undertaken to integrate sustainability thinking and practice into engineering/built environment curricula in Asia-Pacific…

  8. Fan Noise Test Facility

    NASA Image and Video Library

    1969-01-21

    The Fan Noise Test Facility built at the Lewis Research Center to obtain far-field noise data for the National Aeronautics and Space Administration (NASA) and General Electric Quiet Engine Program. The engine incorporated existing noise reduction methods into an engine of similar power to those that propelled the Boeing 707 or McDonnell-Douglas DC-8 airliner. The new the low-bypass ratio turbofan engines of the 1960s were inherently quieter than their turbojet counterparts, researchers had a better grasp of the noise generation problem, and new acoustic technologies had emerged. Lewis contracted General Electric in 1969 to build and aerodynamically test three experimental engines with 72-inch diameter fans. The engines were then brought to Lewis and tested with an acoustically treated nacelle. This Fan Noise Test Facility was built off of the 10- by 10-Foot Supersonic Wind Tunnel’s Main Compressor and Drive Building. Lewis researchers were able to isolate the fan’s noise during these initial tests by removing the core of the engine. The Lewis test rig drove engines to takeoff tip speeds of 1160 feet per second. The facility was later used to test a series of full-scale model fans and fan noise suppressors to be used with the quiet engine. NASA researchers predicted low-speed single-stage fans without inlet guide vanes and with large spacing between rotors and stators would be quieter. General Electric modified a TF39 turbofan engine by removing the the outer protion of the fan and spacing the blade rows of the inner portion. The tests revealed that the untreated version of the engine generated less noise than was anticipated, and the acoustically treated nacelle substantially reduced engine noise.

  9. Results of initial operation of the Jupiter Oxygen Corporation oxy-fuel 15 MWth burner test facility

    SciTech Connect

    Thomas Ochs, Danylo Oryshchyn, Rigel Woodside, Cathy Summers, Brian Patrick, Dietrich Gross, Mark Schoenfield, Thomas Weber and Dan O'Brien

    2009-04-01

    Jupiter Oxygen Corporation (JOC), in cooperation with the National Energy Technology Laboratory (NETL), constructed a 15 MWth oxy-fuel burner test facility with Integrated Pollutant Removal (IPRTM) to test high flame temperature oxy-fuel combustion and advanced carbon capture. Combustion protocols include baseline air firing with natural gas, oxygen and natural gas firing with and without flue gas recirculation, and oxygen and pulverized coal firing with flue gas recirculation. Testing focuses on characterizing burner performance, determining heat transfer characteristics, optimizing CO2 capture, and maximizing heat recovery, with an emphasis on data traceability to address retrofit of existing boilers by directly transforming burner systems to oxy-fuel firing.

  10. LUX - A recirculating linac-based ultrafast X-ray source

    SciTech Connect

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  11. Thermal characterization of an AMTEC recirculating test cell. [Alkali Metal ThermoElectric Converter

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Bankston, C. P.

    1990-01-01

    An alkali metal thermoelectric converter (AMTEC) recirculating test cell has been operated in order to determine the magnitudes of the primary heat losses of the cell and the value of the emissivity of the condenser surface. The energy balance included radiation losses, conductive losses, and losses due to the flow of sodium into the cell. The radiative heat flux dominated the heat loss mechanism of the cell at open circuit, and the condenser emissivity was calculated to be about 0.1. It is shown that, if this emissivity can be reduced to 0.02, then parasitic losses in an AMTEC recirculating test cell operating near peak power would be less than 40 percent of the heat required by the cell. The condenser emissivity decreases with elapsed time, resulting in improved thermal performance of the cell.

  12. CFB combustor with internal solids recirculation -- Pilot testing and design applications

    SciTech Connect

    Belin, F.; Maryamchik, M.; Fuller, T.A.; Perna, M.A.

    1995-12-31

    The new generation of B and W`s CFB boilers with entirely internal recirculation of solids collected by the primary impact separator is uniquely compact and features a simple, low-maintenance solids collection system. Thorough testing of the new concept at the Cold CFB Model and the 2.5 MWth Pilot CFB combustor confirmed its effective performance equal to that of a CFB unit with external solids recirculation from the primary separator. While providing overall advantages of compactness and simplicity, the new design is especially valuable for repowering of the existing power plants where B and W`s CFB boiler fits into the plan area of PC-fired boilers.

  13. Removal of sodium chloride from human urine via batch recirculation electrodialysis at constant applied voltage

    NASA Technical Reports Server (NTRS)

    Gordils-Striker, Nilda E.; Colon, Guillermo

    2003-01-01

    The removal of sodium chloride (NaCl) from human urine using a six-compartment electrodialysis cell with batch recirculation mode of operation for use in advanced life support systems (ALSS) was studied. From the results obtained, batch recirculation at constant applied voltage yields high values (approximately 94% of NaCl removal. Based on the results, the initial rate of NaCl removal was correlated to a power function of the applied voltage: -r=2.0 x 10(-4)E(3.8). With impedance spectroscopy methods, it was also found that the anion membranes were more affected by fouling with an increase of the ohmic resistance of almost 11% compared with 7.4% for the cationic ones.

  14. Identification and origin of plant pathogenic microorganisms in recirculating nutrient solutions

    NASA Astrophysics Data System (ADS)

    Stanghellini, M. E.; Rasmussen, S. L.

    1994-11-01

    Avoidance of root-infecting microorganisms was originally considered one of the advantages of cultivation of crops in a soilless, recirculating nutrient solution. However, to date, four viral, three bacterial and 21 fungal pathogens have been identified as causal agents of root disease in hydroponically-grown crops. Root-infecting fungi, particularly those which produce a motile stage known as a zoospore, have been the primary pathogens associated with extensive crop losses. Documented sources of these root pathogens in hydroponic systems include peat, surface water such as rivers and streams, and insects. The severity of disease caused by these introduced root pathogens is primarily governed by the genetic susceptibility of each crop and the temperature of the recirculating nutrient solution.

  15. Manipulating flow separation: sensitivity of stagnation points, separatrix angles and recirculation area to steady actuation.

    PubMed

    Boujo, E; Gallaire, F

    2014-10-08

    A variational technique is used to derive analytical expressions for the sensitivity of several geometric indicators of flow separation to steady actuation. Considering the boundary layer flow above a wall-mounted bump, the six following representative quantities are considered: the locations of the separation point and reattachment point connected by the separatrix, the separation angles at these stagnation points, the backflow area and the recirculation area. For each geometric quantity, linear sensitivity analysis allows us to identify regions which are the most sensitive to volume forcing and wall blowing/suction. Validations against full nonlinear Navier-Stokes calculations show excellent agreement for small-amplitude control for all considered indicators. With very resemblant sensitivity maps, the reattachment point, the backflow and recirculation areas are seen to be easily manipulated. By contrast, the upstream separation point and the separatrix angles are seen to remain extremely robust with respect to external steady actuation.

  16. Manipulating flow separation: sensitivity of stagnation points, separatrix angles and recirculation area to steady actuation

    PubMed Central

    Boujo, E.; Gallaire, F.

    2014-01-01

    A variational technique is used to derive analytical expressions for the sensitivity of several geometric indicators of flow separation to steady actuation. Considering the boundary layer flow above a wall-mounted bump, the six following representative quantities are considered: the locations of the separation point and reattachment point connected by the separatrix, the separation angles at these stagnation points, the backflow area and the recirculation area. For each geometric quantity, linear sensitivity analysis allows us to identify regions which are the most sensitive to volume forcing and wall blowing/suction. Validations against full nonlinear Navier−Stokes calculations show excellent agreement for small-amplitude control for all considered indicators. With very resemblant sensitivity maps, the reattachment point, the backflow and recirculation areas are seen to be easily manipulated. By contrast, the upstream separation point and the separatrix angles are seen to remain extremely robust with respect to external steady actuation. PMID:25294968

  17. Computational fluid dynamics analysis of external recirculation flow at updraft gasifier using ejector

    NASA Astrophysics Data System (ADS)

    Vidiana, Fajri; Surjosatyo, Adi; Nugroho, Yulianto Sulistyo

    2012-06-01

    Gasification process at updraft gasifier produces the amount of more tar than the other gasifier type. To reduce tar at updraft gasifier, it is carried out recirculation of pirolysis gas into combustion zone. Ejector is an equipment used to entrain the secondary fluid flow by moving momentum and energy from high velocity of primary flow (jet). Research carries out the simulation of isothermal 3D using Computational Fluid Dynamics (CFD) to obtain the maximum of recirculation flow at updraft gasifier using ejector. The result of simulation shows that change of nozzle diameter gives great influence at change of total flow for resirculation compared with the change of diameter and length of mixing area and nozzle exit position (NXP). The maximum of resirculation flow 81 lpm at nozzle diameter 0.75 cm.

  18. Influence of increased exhaust gas recirculation ratio on the thermodynamic processes in CI DI engine

    NASA Astrophysics Data System (ADS)

    Pielecha, I.; Skowron, M.; Bueschke, W.; Cieślik, W.; Wisłocki, K.

    2016-09-01

    The aim of the conducted research was the thermodynamic identification of combustion process involving up to 50-60% recirculated exhaust gasses in compression ignition engine. The values of the respective indicators obtained for the high share of exhaust gasses in the cylinder were compared to the values obtained in the engine working without EGR. The research was conducted on the single-cylinder AVL 5804 engine equipped with recirculated gas cooling system. The conditions of combustion process were determined using indicators of engine operation and measurements of fast-varying cylinder pressure. The evaluation of the influence of different share of exhaust gases in the cylinder on the combustion course and heat release was conducted. As a result of the conducted research the possibility of utilizing the high share of exhaust gasses (50-60%) with simultaneous ecological benefits, not only in relation to nitrogen oxides, was demonstrated.

  19. Removal of sodium chloride from human urine via batch recirculation electrodialysis at constant applied voltage

    NASA Technical Reports Server (NTRS)

    Gordils-Striker, Nilda E.; Colon, Guillermo

    2003-01-01

    The removal of sodium chloride (NaCl) from human urine using a six-compartment electrodialysis cell with batch recirculation mode of operation for use in advanced life support systems (ALSS) was studied. From the results obtained, batch recirculation at constant applied voltage yields high values (approximately 94% of NaCl removal. Based on the results, the initial rate of NaCl removal was correlated to a power function of the applied voltage: -r=2.0 x 10(-4)E(3.8). With impedance spectroscopy methods, it was also found that the anion membranes were more affected by fouling with an increase of the ohmic resistance of almost 11% compared with 7.4% for the cationic ones.

  20. Peripheral regulatory T lymphocytes recirculating to the thymus suppress the development of their precursors.

    PubMed

    Thiault, Nicolas; Darrigues, Julie; Adoue, Véronique; Gros, Marine; Binet, Bénédicte; Perals, Corine; Leobon, Bertrand; Fazilleau, Nicolas; Joffre, Olivier P; Robey, Ellen A; van Meerwijk, Joost P M; Romagnoli, Paola

    2015-06-01

    Most T lymphocytes, including regulatory T cells (Treg cells), differentiate in the thymus. The age-dependent involution of this organ leads to decreasing production of T cells. Here we found that the output of new Treg cells from the thymus decreased substantially more than that of conventional T cells. Peripheral mouse and human Treg cells recirculated back to the thymus, where they constituted a large proportion of the pool of Treg cells and displayed an activated and differentiated phenotype. In the thymus, the recirculating cells exerted their regulatory function by inhibiting interleukin 2 (IL-2)-dependent de novo differentiation of Treg cells. Thus, Treg cell development is controlled by a negative feedback loop in which mature progeny cells return to the thymus and restrain development of precursors of Treg cells.

  1. Removal of sodium chloride from human urine via batch recirculation electrodialysis at constant applied voltage.

    PubMed

    Gordils-Striker, Nilda E; Colon, Guillermo

    2003-01-01

    The removal of sodium chloride (NaCl) from human urine using a six-compartment electrodialysis cell with batch recirculation mode of operation for use in advanced life support systems (ALSS) was studied. From the results obtained, batch recirculation at constant applied voltage yields high values (approximately 94% of NaCl removal. Based on the results, the initial rate of NaCl removal was correlated to a power function of the applied voltage: -r=2.0 x 10(-4)E(3.8). With impedance spectroscopy methods, it was also found that the anion membranes were more affected by fouling with an increase of the ohmic resistance of almost 11% compared with 7.4% for the cationic ones.

  2. Hexachlorobenzene uptake by fathead minnows and macroinvertebrates in recirculating sediment/water systems

    SciTech Connect

    Schuytema, G.S.; Krawczyk, D.F.; Griffis, W.L.; Nebeker, A.V.; Robideaux, M.L.

    1990-01-01

    Fathead minnow (Pimephales promelas), the worm, Lumbriculus variegatus, and the amphipods Hyalella azteca and Gammarus lacustris were exposed to hexachlorobenzene (HCB) in water with and without a bed of HCB-spiked sediment. Water HCB concentrations were maintained by recirculation through HCB-packed columns. Recirculating HCB-bound particulates and possibly eroded HCB particulates were an added source of HCB in addition to the sediment bed. Significant bioaccumulation of HCB in animal tissues was observed in water-only and water-sediment exposures. The presence of the HCB-spiked sediment did not result in a significant increase in the uptake of HCB by the organisms, but there was a substantial increase in sediment HCB levels over time. Higher tissue HCB levels in aquaria without sediment suggest that the sediment was a more efficient sink for HCB than the organisms.

  3. Effect of enhanced leachate recirculated (ELR) landfill operation and gas extraction on greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Samir, Sonia

    The bioreactor/ enhanced leachate recirculated (ELR) landfill operation with the addition of moisture/ leachate to the landfill, accelerate the process of landfill waste decomposition; and increase the generation of LFG over a shorter period of time. Since emissions from the landfills are directly related to the gas generation, the increase in gas generation might also increase the emission from the landfill. On the contrary, the presence of gas extraction is suggested to mitigate the fugitive emissions from the landfills. Therefore, the motivation of the current study was to evaluate the effect of ELR operation as well as the gas extraction on the greenhouse gas emissions from the landfill. The current study was conducted in the City of Denton Landfill, Texas. Methane emission was investigated using a portable FID and static flux chamber technique from the landfill surface. Emission was measured from an ELR operated cell (cell 2) as well as a conventional cell (cell 0) in the City of Denton Landfill. Methane emission for cell 2 varied from 9544.3 ppm to 0 ppm while for cell 0, it varied from 0 ppm to 47 ppm. High spatial variations were observed during monitoring from both cells 0 and cell 2 which could be recognized as the variation of gas generation below the cover soil. The comparison between emissions from the slope and surface of the landfill showed that more methane emission occurred from the slopes than the top surface. In addition, the average landfill emission showed an increasing trend with increase in temperature and decreasing trend with increasing precipitation. The effect of ELR operation near the recirculation pipes showed a lag period between the recirculation and the maximum emission near the pipe. The emission near the pipe decreased after 1 day of recirculation and after the initial decrease, the emission started to increase and continued to increase up to 7 days after the recirculation. However, approximately after 10 days of recirculation, the

  4. Arcjet Facility

    DTIC Science & Technology

    1991-09-01

    PL-TR--91-3085 PL-TR-- ________AD-A243 948 1-8 ARCJET FACILITY Captain Salvador Castillo October 1991 OVa99 Final Report - - A P P R O V...REPORT DATE 3. REPORT TYPE AND DATES COVERED September 1991 Final Aug 86 to Aug 91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS ARCJET FACILITY PE- 62302F...Electric Propulsion Laboratory has designed and begun installation of an arcjet research facility. A 5 foot by 10 foot long chamber with eight 12 inch

  5. Design and performance characteristics of a low-head recirculating aquaculture tank system for low salinity finfish production

    USDA-ARS?s Scientific Manuscript database

    Water treatment components of a recirculating aquaculture system (RAS) consist mainly of: solid removal devices, biofiltration, aeration, degassing units, and water distribution. For each component, multiple options are available and the selection is based on system volume, system hydrodynamics, fis...

  6. Understanding the Independent and Joint Associations of the Home and Workplace Built Environments on Cardiorespiratory Fitness and Body Mass Index

    PubMed Central

    Hoehner, Christine M.; Allen, Peg; Barlow, Carolyn E.; Marx, Christine M.; Brownson, Ross C.; Schootman, Mario

    2013-01-01

    This observational study examined the associations of built environment features around the home and workplace with cardiorespiratory fitness (CRF) based on a treadmill test and body mass index (BMI) (weight (kg)/height (m)2). The study included 8,857 adults aged 20–88 years who completed a preventive medical examination in 2000–2007 while living in 12 Texas counties. Analyses examining workplace neighborhood characteristics included a subset of 4,734 participants. Built environment variables were derived around addresses by using geographic information systems. Models were adjusted for individual-level and census block group–level demographics and socioeconomic status, smoking, BMI (in CRF models), and all other home or workplace built environment variables. CRF was associated with higher intersection density, higher number of private exercise facilities around the home and workplace, larger area of vegetation around the home, and shorter distance to the closest city center. Aside from vegetation, these same built environment features around the home were also associated with BMI. Participants who lived and worked in neighborhoods in the lowest tertiles for intersection density and the number of private exercise facilities had lower CRF and higher BMI values than participants who lived and worked in higher tertiles for these variables. This study contributes new evidence to suggest that built environment features around homes and workplaces may affect health. PMID:23942215

  7. Mechanical design of the recirculating, terminal pumping in the Lund Pelletron, and experimental experience

    NASA Astrophysics Data System (ADS)

    Hellborg, R.; Håkansson, K.; Faarinen, M.; Kiisk, M.; Persson, P.; Skog, G.; Stenström, K.

    2002-11-01

    A recirculating terminal pumping system has been installed in the 3 MV Pelletron tandem accelerator in Lund. An extremly limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass spectrometry, will be given.

  8. Evaluation of leachate recirculation on nitrous oxide production in the Likang Landfill, China.

    PubMed

    Lee, Chun Man; Lin, Xue Rui; Lan, Chong Yu; Lo, Samuel Chun Lap; Chan, Gilbert Yuk Sing

    2002-01-01

    Landfill leachate recirculation is efficient in reducing the leachate quantity handled by a leachate treatment plant. However, after land application of leachate, nitrification and denitrification of the ammoniacal N becomes possible and the greenhouse gas nitrous oxide (N2O) is produced. Lack of information on the effects of leachate recirculation on N2O production led to a field study being conducted in the Likang Landfill (Guangzhou, China) where leachate recirculation had been practiced for 8 yr. Monthly productions and fluxes of N2O from leachate and soil were studied from June to November 2000. Environmental and chemical factors regulating N2O production were also accessed. An impermeable top liner was not used at this site; municipal solid waste was simply covered by inert soil and compacted by bulldozers. A high N2O emission rate (113 mg m-2 h-1) was detected from a leachate pond purposely formed on topsoil within the landfill boundary after leachate irrigation. A high N2O level (1.09 micrograms L-1) was detected in a gas sample emitted from topsoil 1 m from the leachate pond. Nitrous oxide production from denitrification in leachate-contaminated soil was at least 20 times higher than that from nitrification based on laboratory incubation studies. The N2O levels emitted from leachate ponds were compared with figures reported for different ecosystems and showed that the results of the present study were 68.7 to 88.6 times higher. Leachate recirculation can be a cost-effective operation in reducing the volume of leachate to be treated in landfill. However, to reduce N2O flux, leachate should be applied to underground soil rather than being irrigated and allowed to flow on topsoil.

  9. Use of thermoplastic pipe in recirculating water systems in petroleum refineries and petrochemical plants

    SciTech Connect

    Karelin, Ya.A.; Yaromskii, V.N.

    1987-07-01

    The authors discuss the use of thermoplastic pipe for combating corrosion in water supply systems. The pipe used was fabricated from low-pressure and high-pressure polyethylene (HPPE and LPPE) and unplasticized polyvinyl chloride PVC-100. The resistance of the plastic pipe to the action of recirculating water was evaluated on the basis of changes in their physicomechanical properties. The results of mechanical tests on the specimens are shown.

  10. Electron Recirculation in Electrostatic Multicusp Systems: 1. Confinement and Losses in Simple Power Law Wells

    DTIC Science & Technology

    1991-04-19

    ELECTROSTATIC MULTICUSP SYSTEMS: I - CONFINEMENT AND LOSSES IN SIMPLE POWER LAW WELLSt Robert W. Bussard and Accesion For Katherine E. King NTIS CRA&I DTIC TAB...9100 A Center Street, Manassas, VA 22110, (703) 330-7990 92-’ 9 q2-f- ,f ELECTRON RECIRCULATION IN ELECTROSTATIC MULTICUSP SYSTEMS: I - CONFINEMENT AND...confinement in Polywellt*-type multicusp systems. These are special polyhedral configurations 6 . 7 that allow formation of stable deep electrostatic

  11. Conditions for coherent-synchrotron-radiation-induced microbunching suppression in multibend beam transport or recirculation arcs

    NASA Astrophysics Data System (ADS)

    Tsai, C.-Y.; Di Mitri, S.; Douglas, D.; Li, R.; Tennant, C.

    2017-02-01

    The coherent synchrotron radiation (CSR) of a high-brightness electron beam traversing a series of dipoles, such as transport or recirculation arcs, may result in beam phase space degradation. On one hand, CSR can perturb electron transverse motion in dispersive regions along the beam line and possibly cause emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching instability. For transport arcs, several schemes have been proposed to suppress the CSR-induced emittance growth. Correspondingly, a few scenarios have been introduced to suppress CSR-induced microbunching instability, which however mostly aim for linac-based machines. In this paper we provide sufficient conditions for suppression of CSR-induced microbunching instability along transport or recirculation arcs. Examples are presented with the relevant microbunching analyses carried out by our developed semianalytical Vlasov solver [C.-Y. Tsai, D. Douglas, R. Li, and C. Tennant, Linear microbunching analysis for recirculation machines, Phys. Rev. ST Accel. Beams 19, 114401 (2016), 10.1103/PhysRevAccelBeams.19.114401]. The example lattices include low-energy (˜100 MeV ) and high-energy (˜1 GeV ) recirculation arcs, and medium-energy compressor arcs. Our studies show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. Beam current dependences of maximal CSR microbunching gains are also demonstrated, which should help outline a beam line design for different scales of nominal currents. We expect this analysis can shed light on the lattice design approach that aims to control the CSR-induced microbunching.

  12. Experimental verification of a secondary recirculation zone in a labyrinth seal

    NASA Technical Reports Server (NTRS)

    Morrison, G. L.; Tatterson, G. B.; Johnson, M. C.

    1988-01-01

    The existence of a secondary recirculation zone inside the cavities of a labyrinth seal operating at a Reynolds number of 15,000 and a Taylor number of 10,300 has been experimentally verified. A three-dimensional laser Doppler anemometer system was used to measure the complete mean velocity and Reynolds stress tensor distributions in the first, third, fifth and seventh cavities of a seven cavity labyrinth seal which had a clearance of 1.27 mm.

  13. High gradient magnetic beneficiation of dry pulverized coal via upwardly directed recirculating fluidization

    DOEpatents

    Eissenberg, David M.; Liu, Yin-An

    1980-01-01

    This invention relates to an improved device and method for the high gradient magnetic beneficiation of dry pulverized coal, for the purpose of removing sulfur and ash from the coal whereby the product is a dry environmentally acceptable, low-sulfur fuel. The process involves upwardly directed recirculating air fluidization of selectively sized powdered coal in a separator having sections of increasing diameters in the direction of air flow, with magnetic field and flow rates chosen for optimum separations depending upon particulate size.

  14. Evaluating leachate recirculation with cellulase addition to enhance waste biostabilisation and landfill gas production.

    PubMed

    Frank, R R; Davies, S; Wagland, S T; Villa, R; Trois, C; Coulon, F

    2016-09-01

    The effect of leachate recirculation with cellulase augmentation on municipal solid waste (MSW) biostabilisation and landfill gas production was investigated using batch bioreactors to determine the optimal conditions of moisture content, temperature and nutrients. Experimentation was thereafter scaled-up in 7L bioreactors. Three conditions were tested including (1) leachate recirculation only, (2) leachate recirculation with enzyme augmentation and (3) no leachate recirculation (control). Cumulative biogas production of the batch tests indicated that there was little difference between the leachate and control test conditions, producing on average 0.043m(3)biogaskg(-1) waste. However the addition of cellulase at 15×10(6)Utonne(-1) waste doubled the biogas production (0.074m(3)biogaskg(-1) waste). Similar trend was observed with the bioreactors. Cellulase addition also resulted in the highest COD reduction in both the waste and the leachate samples (47% and 42% COD reduction, respectively). In both cases, the quantity of biogas produced was closer to the lower value of theoretical and data-based biogas prediction indicators (0.05-0.4m(3)biogaskg(-1) waste). This was likely due to a high concentration of heavy metals present in the leachate, in particular Cr and Mn, which are known to be toxic to methanogens. The cost-benefit analysis (CBA) based on the settings of the study (cellulase concentration of 15×10(6)Utonne(-1) waste) showed that leachate bioaugmentation using cellulase is economically viable, with a net benefit of approximately €12.1million on a 5Mt mixed waste landfill. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Human skin is protected by four functionally and phenotypically discrete populations of resident and recirculating memory T cells.

    PubMed

    Watanabe, Rei; Gehad, Ahmed; Yang, Chao; Scott, Laura L; Teague, Jessica E; Schlapbach, Christoph; Elco, Christopher P; Huang, Victor; Matos, Tiago R; Kupper, Thomas S; Clark, Rachael A

    2015-03-18

    The skin of an adult human contains about 20 billion memory T cells. Epithelial barrier tissues are infiltrated by a combination of resident and recirculating T cells in mice, but the relative proportions and functional activities of resident versus recirculating T cells have not been evaluated in human skin. We discriminated resident from recirculating T cells in human-engrafted mice and lymphoma patients using alemtuzumab, a medication that depletes recirculating T cells from skin, and then analyzed these T cell populations in healthy human skin. All nonrecirculating resident memory T cells (TRM) expressed CD69, but most were CD4(+), CD103(-), and located in the dermis, in contrast to studies in mice. Both CD4(+) and CD8(+) CD103(+) TRM were enriched in the epidermis, had potent effector functions, and had a limited proliferative capacity compared to CD103(-) TRM. TRM of both types had more potent effector functions than recirculating T cells. We observed two distinct populations of recirculating T cells, CCR7(+)/L-selectin(+) central memory T cells (TCM) and CCR7(+)/L-selectin(-) T cells, which we term migratory memory T cells (TMM). Circulating skin-tropic TMM were intermediate in cytokine production between TCM and effector memory T cells. In patients with cutaneous T cell lymphoma, malignant TCM and TMM induced distinct inflammatory skin lesions, and TMM were depleted more slowly from skin after alemtuzumab, suggesting that TMM may recirculate more slowly. In summary, human skin is protected by four functionally distinct populations of T cells, two resident and two recirculating, with differing territories of migration and distinct functional activities. Copyright © 2015, American Association for the Advancement of Science.

  16. Generation of Flat Optical Frequency Comb based on Mach-Zehnder Modulator and Recirculating Frequency Shifter Loop

    NASA Astrophysics Data System (ADS)

    Wu, Shibao; Li, Yulong; Fei, Yue; Hu, Faze

    2014-06-01

    We propose a novel scheme to generate optical frequency comb by using Mach-Zehnder modulator and recirculating frequency shifter loop based on IQ modulator driven by radio frequency clock signals. A system of 4 flat and stable comb lines generation based on Mach-Zehnder modulator is set as the seed light source of the recirculating loop. Through theorical analysis and simulation it is shown that the proposed theoretical model is proved in good agreement with simulation results.

  17. Mixer assembly for a gas turbine engine having a pilot mixer with a corner flame stabilizing recirculation zone

    NASA Technical Reports Server (NTRS)

    Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Fotache, Catalin G. (Inventor)

    2012-01-01

    A mixer assembly for a gas turbine engine is provided, including a main mixer, and a pilot mixer having an annular housing in which a corner is formed between an aft portion of the housing and a bulkhead wall in which a corner recirculation zone is located to stabilize and anchor the flame of the pilot mixer. The pilot mixer can further include features to cool the annular housing, including in the area of the corner recirculation zone.

  18. NASA Langley Low Speed Aeroacoustic Wind Tunnel: Background Noise and Flow Survey Results Prior to FY05 Construction of Facilities Modifications

    NASA Technical Reports Server (NTRS)

    Booth, Earl R., Jr.; Henderson, Brenda S.

    2005-01-01

    The NASA Langley Research Center Low Speed Aeroacoustic Wind Tunnel is a premier facility for model-scale testing of jet noise reduction concepts at realistic flow conditions. However, flow inside the open jet test section is less than optimum. A Construction of Facilities project, scheduled for FY 05, will replace the flow collector with a new design intended to reduce recirculation in the open jet test section. The reduction of recirculation will reduce background noise levels measured by a microphone array impinged by the recirculation flow and will improve flow characteristics in the open jet tunnel flow. In order to assess the degree to which this modification is successful, background noise levels and tunnel flow are documented, in order to establish a baseline, in this report.

  19. Advanced Horizontal Well Recirculation Systems for Geothermal Energy Recovery in Sedimentary and Crystalline Formations

    SciTech Connect

    Bruno, Mike S.; Detwiler, Russell L.; Lao, Kang; Serajian, Vahid; Elkhoury, Jean; Diessl, Julia; White, Nicky

    2012-12-13

    There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. The primary objectives of this DOE research effort are to develop and document optimum design configurations and operating practices to produce geothermal power from hot permeable sedimentary and crystalline formations using advanced horizontal well recirculation systems. During Phase I of this research project Terralog Technologies USA and The University of California, Irvine (UCI), have completed preliminary investigations and documentation of advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. We have also identified significant geologic resources appropriate for application of such technology. The main challenge for such recirculation systems is to optimize both the design configuration and the operating practices for cost-effective geothermal energy recovery. These will be strongly influenced by sedimentary formation properties, including thickness and dip, temperature, thermal conductivity, heat capacity, permeability, and porosity; and by working fluid properties.

  20. Upwelling-triggered near-geostrophic recirculation in an equatorward facing embayment

    NASA Astrophysics Data System (ADS)

    Moraga-Opazo, Julio; Valle-Levinson, Arnoldo; Ramos, Marcel; Pizarro-Koch, Matías

    2011-12-01

    Underway current velocity profiles were combined with hydrographic profiles at the entrance to Tongoy Bay, an equatorward facing bay in north-central Chile, with the objective of determining its exchange hydrodynamics. To the west, Tongoy Bay is bounded by Lengua de Vaca Point, a ˜6 km-long northward protruding peninsula. Observations were obtained during three surveys (April 2005, December 2005, May 2009) along cross-bay transects for at least one full day. During the surveys, winds were upwelling-favorable and displayed diurnal variations. Non-tidal (tidally averaged) flows showed a consistent clockwise or southern hemisphere cyclonic, recirculation during the three surveys. This recirculation was likely part of a cyclonic gyre (10-20 km in diameter), not entirely resolved by the surveys, and formed by flow separation off Lengua de Vaca Point. Estimates of the baroclinic pressure gradient, combined with analytical solutions of density-driven and wind-driven flows, indicated that the recirculation in Tongoy Bay was nearly in geostrophic balance. An ageostrophic contribution to the dynamics was related to frictional effects derived from local upwelling-favorable winds. A linear superposition of the analytically derived density-driven and wind-driven exchange resulted in a flow pattern that resembled the observed net exchange flows at the bay mouth.