Characterization of a Recoverable Flight Control Computer System

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar; Torres, Wilfredo

1999-01-01

The design and development of a Closed-Loop System to study and evaluate the performance of the Honeywell Recoverable Computer System (RCS) in electromagnetic environments (EME) is presented. The development of a Windows-based software package to handle the time-critical communication of data and commands between the RCS and flight simulation code in real-time while meeting the stringent hard deadlines is also submitted. The performance results of the RCS and characteristics of its upset recovery scheme while exercising flight control laws under ideal conditions as well as in the presence of electromagnetic fields are also discussed.

40 CFR 85.525 - Applicable standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... prohibition, vehicles/engines that have been converted to operate on a different fuel must meet emission standards and related requirements as follows: (a) The modified vehicle/engine must meet the requirements that applied for the OEM vehicle/engine, or the most stringent OEM vehicle/engine standards in any...

Accelerator tube construction and characterization for a tandem-electrostatic-quadrupole for accelerator-based boron neutron capture therapy.

PubMed

Cartelli, D; Vento, V Thatar; Castell, W; Di Paolo, H; Kesque, J M; Bergueiro, J; Valda, A A; Erhardt, J; Kreiner, A J

2011-12-01

The accelerator tubes are essential components of the accelerator. Their function is to transport and accelerate a very intense proton or deuteron beam through the machine, from the ion source to the neutron production target, without significant losses. In this contribution, we discuss materials selected for the tube construction, the procedures used for their assembly and the testing performed to meet the stringent requirements to which it is subjected. Copyright © 2011 Elsevier Ltd. All rights reserved.

Design and Performance of the Terrestrial Planet Finder Coronagraph

NASA Technical Reports Server (NTRS)

White, Mary L.; Shaklan, Stuart; Lisman, P. Doulas; Ho, Timothy; Mouroulis, Pantazis; Basinger, Scott; Ledeboer, Bill; Kwack, Eug; Kissil, Andy; Mosier, Gary;

Welding and joining techniques.

PubMed

Chipperfield, F A; Dunkerton, S B

2001-05-01

There is a welding solution for most applications. As products must meet more stringent requirements or require more flexible processes to aid design or reduce cost, further improvements or totally new processes are likely to be developed. Quality control aspects are also becoming more important to meet regulation, and monitoring and control of welding processes and the standardised testing of joints will meet some if not all of these requirements.

2017-04-28_W88 ALT 370 Program Overview(OUO).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniels, Vonceil

2017-04-01

All major program milestones have been met and the program is executing within budget. The ALT 370 program achieved Phase 6.4 authorization in February of this year. Five component Final Design Reviews (FDRs) have been completed, indicating progress in finalizing the design and development phase of the program. A series of ground-based qualification activities have demonstrated that designs are meeting functional requirements. The first fully functional flight test, FCET-53, demonstrated end-to-end performance in normal flight environments in February. Similarly, groundbased nuclear safety and hostile environments testing indicates that the design meets requirements in these stringent environments. The first in amore » series of hostile blast tests was successfully conducted in April.« less

DFB laser - External modulator fiber optic delay line for radar applications

NASA Astrophysics Data System (ADS)

Newberg, I. L.; Gee, C. M.; Thurmond, G. D.; Yen, H. W.

1989-09-01

A new application of a long fiber-optic delay line as a radar repeater in a radar test set is described. The experimental 31.6-kilometer fiber-optic link includes an external modulator operating with a distributed-feedback laser and low-loss single-mode fiber matched to the laser wavelength to obtain low dispersion for achieving large bandwidth-length performance. The successful tests, in which pulse compression peak sidelobe measurements are used to confirm the link RF phase linearity and SNR performance, show that fiber-optic links can meet the stringent phase and noise requirements of modern radars at high microwave frequencies.

High-resolution AM LCD development for avionic applications

NASA Astrophysics Data System (ADS)

Lamberth, Larry S.; Laddu, Ravindra R.; Harris, Doug; Sarma, Kalluri R.; Li, Wang-Yang; Chien, C. C.; Chu, C. Y.; Lee, C. S.; Kuo, Chen-Lung

2003-09-01

For the first time, an avionic grade MVA AM LCD with wide viewing angle has been developed for use in either landscape or portrait mode. The development of a high resolution Multi-domain Vertical Alignment (MVA) Active Matrix Liquid Crystal Display (AM LCD) is described. Challenges met in this development include achieving the required performance with high luminance and sunlight readability while meeting stringent optical (image quality) and environmental performance requirements of avionics displays. In this paper the optical and environmental performance of this high resolution 14.1" MVA-AM-LCD are discussed and some performance comparisons to conventional AM-LCDs are documented. This AM LCD has found multiple Business Aviation and Military display applications and cockpit pictures are presented.

Pointing and tracking space mechanism for laser communication

NASA Technical Reports Server (NTRS)

Brunschvig, A.; Deboisanger, M.

1994-01-01

Space optical communication is considered a promising technology regarding its high data rate and confidentiality capabilities. However, it requires today complex satellite systems involving highly accurate mechanisms. This paper aims to highlight the stringent requirements which had to be fulfilled for such a mechanism, the way an existing design has been adapted to meet these requirements, and the main technical difficulties which have been overcome thanks to extensive development tests throughout the C/D phase initiated in 1991. The expected on-orbit performance of this mechanism is also presented.

DSN radio science system design and testing for Voyager-Neptune encounter

NASA Technical Reports Server (NTRS)

Ham, N. C.; Rebold, T. A.; Weese, J. F.

1989-01-01

The Deep Space Network (DSN) Radio Science System presently implemented within the Deep Space Network was designed to meet stringent requirements imposed by the demands of the Voyager-Neptune encounter and future missions. One of the initial parameters related to frequency stability is discussed. The requirement, specification, design, and methodology for measuring this parameter are described. A description of special instrumentation that was developed for the test measurements and initial test data resulting from the system tests performed at Canberra, Australia and Usuda, Japan are given.

NASA management of the Space Shuttle Program

NASA Technical Reports Server (NTRS)

Peters, F.

1975-01-01

The management system and management technology described have been developed to meet stringent cost and schedule constraints of the Space Shuttle Program. Management of resources available to this program requires control and motivation of a large number of efficient creative personnel trained in various technical specialties. This must be done while keeping track of numerous parallel, yet interdependent activities involving different functions, organizations, and products all moving together in accordance with intricate plans for budgets, schedules, performance, and interaction. Some techniques developed to identify problems at an early stage and seek immediate solutions are examined.

Model predictive control of a lean-burn gasoline engine coupled with a passive selective catalytic reduction system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Pingen; Lin, Qinghua; Prikhodko, Vitaly Y.

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuelmore » penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.« less

40 CFR 63.2241 - What are the work practice requirements and how must I meet them?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Products Compliance Options, Operating Requirements, and Work Practice Requirements § 63.2241 What are the...) If you have a dry rotary dryer, you may choose to designate your dry rotary dryer as a green rotary dryer and meet the more stringent compliance options and operating requirements in § 63.2240 for green...

Performance and Reliability of Bonded Interfaces for High-Temperature Packaging. Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeVoto, Douglas

2016-04-01

Current generation automotive power electronics packages utilize silicon devices and lead-free solder alloys. To meet stringent technical targets for 2020 and beyond (for cost, power density, specific power, efficiency and reliability), wide-bandgap devices are being considered since they offer advantages such as operation at higher frequencies, voltages, and temperatures. Traditional power electronics packages must be redesigned to utilize the full potential of wide-bandgap devices, and the die- and substrate-attach layers are key areas where new material development and validation is required. Present solder alloys do not meet the performance requirements for these new package designs while also meeting cost andmore » hazardous substance restrictions. Sintered silver (Ag) promises to meet the needs for die- and substrate-attach interfaces but synthesis optimization and reliability evaluation must be completed. Sintered Ag material was proposed as an alternative solution in power electronics packages almost 20 years back. However, synthesis pressure requirements up 40 MPa caused a higher complexity in the production process and more stringent flatness specifications for the substrates. Recently, several manufacturers have developed sintered Ag materials that require lower (3-5 MPa) or even no bonding pressures. Degradation mechanisms for these sintered Ag materials are not well known and need to be addressed. We are addressing these aspects to some extent in this project. We are developing generalized (i.e., independent of geometry) stress intensity factor versus cycles-to-failure relations for sintered Ag. Because sintered Ag is a relatively new material for automotive power electronics, the industry currently does not have a good understanding of recommended synthesis parameters or expected reliability under prescribed conditions. It is an important deliverable of this project to transfer findings to industry to eliminate barriers to using sintered Ag as a viable and commercialized die- and substrate-attach material. Only a few manufacturers produce sintered Ag pastes and may consider some processing conditions as proprietary. It is the goal of this project to openly explore and define best practices in order to impact the maximum number of power electronics module manufacturers and suppliers.« less

Scanning mirror for infrared sensors

NASA Technical Reports Server (NTRS)

Anderson, R. H.; Bernstein, S. B.

1972-01-01

A high resolution, long life angle-encoded scanning mirror, built for application in an infrared attitude sensor, is described. The mirror uses a Moire' fringe type optical encoder and unique torsion bar suspension together with a magnetic drive to meet stringent operational and environmental requirements at a minimum weight and with minimum power consumption. Details of the specifications, design, and construction are presented with an analysis of the mirror suspension that allows accurate prediction of performance. The emphasis is on mechanical design considerations, and brief discussions are included on the encoder and magnetic drive to provide a complete view of the mirror system and its capabilities.

Ideas for Future GPS Timing Improvements

NASA Technical Reports Server (NTRS)

Hutsell, Steven T.

1996-01-01

Having recently met stringent criteria for full operational capability (FOC) certification, the Global Positioning System (GPS) now has higher customer expectations than ever before. In order to maintain customer satisfaction, and the meet the even high customer demands of the future, the GPS Master Control Station (MCS) must play a critical role in the process of carefully refining the performance and integrity of the GPS constellation, particularly in the area of timing. This paper will present an operational perspective on several ideas for improving timing in GPS. These ideas include the desire for improving MCS - US Naval Observatory (USNO) data connectivity, an improved GPS-Coordinated Universal Time (UTC) prediction algorithm, a more robust Kalman Filter, and more features in the GPS reference time algorithm (the GPS composite clock), including frequency step resolution, a more explicit use of the basic time scale equation, and dynamic clock weighting. Current MCS software meets the exceptional challenge of managing an extremely complex constellation of 24 navigation satellites. The GPS community will, however, always seek to improve upon this performance and integrity.

Joint Optics Structures Experiment (JOSE)

NASA Technical Reports Server (NTRS)

Founds, David

1987-01-01

The objectives of the JOSE program is to develop, demonstrate, and evaluate active vibration suppression techniques for Directed Energy Weapons (DEW). DEW system performance is highly influenced by the line-of-sight (LOS) stability and in some cases by the wave front quality. The missions envisioned for DEW systems by the Strategic Defense Initiative require LOS stability and wave front quality to be significantly improved over any current demonstrated capability. The Active Control of Space Structures (ACOSS) program led to the development of a number of promising structural control techniques. DEW structures are vastly more complex than any structures controlled to date. They will be subject to disturbances with significantly higher magnitudes and wider bandwidths, while holding higher tolerances on allowable motions and deformations. Meeting the performance requirements of the JOSE program requires upgrading the ACOSS techniques to meet new more stringent requirements, the development of requisite sensors and acturators, improved control processors, highly accurate system identification methods, and the integration of hardware and methodologies into a successful demonstration.

Tradeoff analysis of technology needs for public service helicopters

NASA Technical Reports Server (NTRS)

Bauchspies, J. S.; Bryant, W. R., Jr.; Simpson, W. E.

1985-01-01

The design requirements for a family or type of Public Service Helicopter (PSH) is examined which will satisfy the needs of municipal and state governments in the following mission areas: Emergency Medical Service--Airborne Rescue Squad; Law Enforcement; Search and Rescue; and Environmental Control (Fire Fighting, Pollution, Resource Management). The report compares both design and performance requirements as specified by the PSH user's group against current technological capabilities, RTOPS and US Army LHX design requirements. The study explores various design trade-offs and options available to the aircraft designer/manufacturer in order to meet the several criteria specified by the PSH user's group. In addition, the report includes a brief assessment of the feasibility of employing certain advanced rotorcraft designs to meet the stringent combination of operational capabilities desired by the Public Service Helicopter Users.

[Mechanical Shimming Method and Implementation for Permanent Magnet of MRI System].

PubMed

Xue, Tingqiang; Chen, Jinjun

2015-03-01

A mechanical shimming method and device for permanent magnet of MRI system has been developed to meet its stringent homogeneity requirement without time-consuming passive shimming on site, installation and adjustment efficiency has been increased.

GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

NASA Astrophysics Data System (ADS)

Khanafseh, Samer Mahmoud

Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted measurements as an additional inter-vehicle ranging measurement were also introduced. The algorithms and methods developed in this work are generally applicable to realize high-performance GPS-based navigation in partially obstructed environments. Navigation performance for AAR was quantified through covariance analysis, and it was shown that the stringent navigation requirements for this application are achievable. Finally, a real-time implementation of the algorithms was developed and successfully validated in autopiloted flight tests.

The Streptococcus agalactiae Stringent Response Enhances Virulence and Persistence in Human Blood

PubMed Central

Hooven, Thomas A.; Catomeris, Andrew J.; Bonakdar, Maryam; Tallon, Luke J.; Santana-Cruz, Ivette; Ott, Sandra; Daugherty, Sean C.; Tettelin, Hervé

2017-01-01

ABSTRACT Streptococcus agalactiae (group B Streptococcus [GBS]) causes serious infections in neonates. We previously reported a transposon sequencing (Tn-seq) system for performing genomewide assessment of gene fitness in GBS. In order to identify molecular mechanisms required for GBS to transition from a mucosal commensal lifestyle to bloodstream invasion, we performed Tn-seq on GBS strain A909 with human whole blood. Our analysis identified 16 genes conditionally essential for GBS survival in blood, of which 75% were members of the capsular polysaccharide (cps) operon. Among the non-cps genes identified as conditionally essential was relA, which encodes an enzyme whose activity is central to the bacterial stringent response—a conserved adaptation to environmental stress. We used blood coincubation studies of targeted knockout strains to confirm the expected growth defects of GBS deficient in capsule or stringent response activation. Unexpectedly, we found that the relA knockout strains demonstrated decreased expression of β-hemolysin/cytolysin, an important cytotoxin implicated in facilitating GBS invasion. Furthermore, chemical activation of the stringent response with serine hydroxamate increased β-hemolysin/cytolysin expression. To establish a mechanism by which the stringent response leads to increased cytotoxicity, we performed transcriptome sequencing (RNA-seq) on two GBS strains grown under stringent response or control conditions. This revealed a conserved decrease in the expression of genes in the arginine deiminase pathway during stringent response activation. Through coincubation with supplemental arginine and the arginine antagonist canavanine, we show that arginine availability is a determinant of GBS cytotoxicity and that the pathway between stringent response activation and increased virulence is arginine dependent. PMID:29109175

Colorado River Sewer System Joint Venture to Upgrade Wastewater System

EPA Pesticide Factsheets

SAN FRANCISCO -Today, the Colorado River Sewer System Joint Venture, located in Parker, Ariz. entered into an agreement with the EPA to upgrade their wastewater treatment system to meet stringent water quality standards. The cost of the upgrade is ap

Development of Temperature Sensitive Paints for the Detection of Small Temperature Differences

NASA Technical Reports Server (NTRS)

Oglesby, Donald M.; Upchurch, Billy T.; Sealey, Bradley S.; Leighty, Bradley D.; Burkett, Cecil G., Jr.; Jalali, Amir

1997-01-01

Temperature sensitive paints (TSP s) have recently been used to detect small temperature differences on aerodynamic model surfaces. These types of applications impose stringent performance requirements on a paint system. The TSP s must operate over a broad temperature range, must be physically robust (cannot chip or peel), must be polishable to at least the smoothness of the model surface, and must have sufficient sensitivity to detect small temperature differences. TSP coatings based on the use of metal complexes in polymer binders were developed at NASA Langley Research Center which meet most of the requirements for detection of small temperature differences under severe environmental conditions.

Thermal Design to Meet Stringent Temperature Gradient/Stability Requirements of SWIFT BAT Detectors

NASA Technical Reports Server (NTRS)

Choi, Michael K.

2000-01-01

The Burst Alert Telescope (BAT) is an instrument on the National Aeronautics and Space Administration (NASA) SWIFT spacecraft. It is designed to detect gamma ray burst over a broad region of the sky and quickly align the telescopes on the spacecraft to the gamma ray source. The thermal requirements for the BAT detector arrays are very stringent. The maximum allowable temperature gradient of the 256 cadmium zinc telluride (CZT) detectors is PC. Also, the maximum allowable rate of temperature change of the ASICs of the 256 Detector Modules (DMs) is PC on any time scale. The total power dissipation of the DMs and Block Command & Data Handling (BCDH) is 180 W. This paper presents a thermal design that uses constant conductance heat pipes (CCHPs) to minimize the temperature gradient of the DMs, and loop heat pipes (LHPs) to transport the waste heat to the radiator. The LHPs vary the effective thermal conductance from the DMs to the radiator to minimize heater power to meet the heater power budget, and to improve the temperature stability. The DMs are cold biased, and active heater control is used to meet the temperature gradient and stability requirements.

Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

AUGUSTONI, ARNOLD L.

Laser safety evaluation and output emission measurements were performed (during October and November 2001) on SNL MILES and Mini MILES laser emitting components. The purpose, to verify that these components, not only meet the Class 1 (eye safe) laser hazard criteria of the CDRH Compliance Guide for Laser Products and 21 CFR 1040 Laser Product Performance Standard; but also meet the more stringent ANSI Std. z136.1-2000 Safe Use of Lasers conditions for Class 1 lasers that govern SNL laser operations. The results of these measurements confirmed that all of the Small Arms Laser Transmitters, as currently set (''as is''), meetmore » the Class 1 criteria. Several of the Mini MILES Small Arms Transmitters did not. These were modified and re-tested and now meet the Class 1 laser hazard criteria. All but one System Controllers (hand held and rifle stock) met class 1 criteria for single trigger pulls and all presented Class 3a laser hazard levels if the trigger is held (continuous emission) for more than 5 seconds on a single point target. All units were Class 3a for ''aided'' viewing. These units were modified and re-tested and now meet the Class 1 hazard criteria for both ''aided'' as well as ''unaided'' viewing. All the Claymore Mine laser emitters tested are laser hazard Class 1 for both ''aided'' as well as ''unaided'' viewing.« less

Environmental Life Cycle Assessment and Cost Analysis of Bath, NY Wastewater Treatment Plant: Potential Upgrade Implications

EPA Science Inventory

Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pot...

Economics of oversized cyclones in the cotton ginning industry

USDA-ARS?s Scientific Manuscript database

Cost of reducing pollution to meet increasingly stringent air quality standards particularly for the U.S. cotton ginning industry is rising overtime. Most industry participants use cyclones to control air pollutants. These cyclones have no moving parts and their initial investment costs are relative...

RT-MATRIX: Measuring Total Organic Carbon by Photocatalytic Oxidation of Volatile Organic Compounds

NASA Technical Reports Server (NTRS)

2008-01-01

Volatile organic compounds (VOCs) inevitably accumulate in enclosed habitats such as the International Space Station and the Crew Exploration Vehicle (CEV) as a result of human metabolism, material off-gassing, and leaking equipment. Some VOCs can negatively affect the quality of the crew's life, health, and performance; and consequently, the success of the mission. Air quality must be closely monitored to ensure a safe living and working environment. Currently, there is no reliable air quality monitoring system that meets NASA's stringent requirements for power, mass, volume, or performance. The ultimate objective of the project -- the development of a Real-Time, Miniaturized, Autonomous Total Risk Indicator System (RT.MATRIX).is to provide a portable, dual-function sensing system that simultaneously determines total organic carbon (TOC) and individual contaminants in air streams.

Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland.

PubMed

Kadewa, W W; Le Corre, K; Pidou, M; Jeffrey, P J; Jefferson, B

2010-01-01

A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m² and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m³ m⁻² d⁻¹ were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of < 2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76-85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L⁻¹ for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD₅ and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.

Principals' Leadership Styles and Student Achievement

ERIC Educational Resources Information Center

Harnish, David Alan

2012-01-01

Many schools struggle to meet No Child Left Behind's stringent adequate yearly progress standards, although the benchmark has stimulated national creativity and reform. The purpose of this study was to explore teacher perceptions of principals' leadership styles, curriculum reform, and student achievement to ascertain possible factors to improve…

Nutrient Removal and Resource Recovery: Effect on Life Cycle Cost and Environmental Impacts of Small Scale Wastewater Treatment

EPA Science Inventory

Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pote...

Early Benchmarks of Product Generation Capabilities of the GOES-R Ground System for Operational Weather Prediction

NASA Astrophysics Data System (ADS)

Kalluri, S. N.; Haman, B.; Vititoe, D.

2014-12-01

The ground system under development for Geostationary Operational Environmental Satellite-R (GOES-R) series of weather satellite has completed a key milestone in implementing the science algorithms that process raw sensor data to higher level products in preparation for launch. Real time observations from GOES-R are expected to make significant contributions to Earth and space weather prediction, and there are stringent requirements to product weather products at very low latency to meet NOAA's operational needs. Simulated test data from all the six GOES-R sensors are being processed by the system to test and verify performance of the fielded system. Early results show that the system development is on track to meet functional and performance requirements to process science data. Comparison of science products generated by the ground system from simulated data with those generated by the algorithm developers show close agreement among data sets which demonstrates that the algorithms are implemented correctly. Successful delivery of products to AWIPS and the Product Distribution and Access (PDA) system from the core system demonstrate that the external interfaces are working.

Characterization of three-way automotive catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenik, E.A.; More, K.L.; LaBarge, W.

1997-04-01

The CRADA between Delphi Automotive Systems (Delphi; formerly General Motors - AC Delco, Systems) and Lockheed Martin Energy Research (LMER) on automotive catalysts was completed at the end of FY96, after a ten month, no-cost extension. The CRADA was aimed at improved performance and lifetime of noble metal based three-way-catalysts (TWC), which are the primary catalytic system for automotive emission control systems. While these TWC can meet the currently required emission standards, higher than optimum noble metal loadings are often required to meet lifetime requirements. In addition, more stringent emission standards will be imposed in the near future, demanding improvedmore » performance and service life from these catalysts. Understanding the changes of TWC conversion efficiency with ageing is a critical need in improving these catalysts. Initially in a fresh catalyst, the active material is often distributed on a very fine scale, approaching single atoms or small atomic clusters. As such, a wide range of analytical techniques have been employed to provide high spatial resolution characterization of the evolving state of the catalytic material.« less

Astrometric Telescope Facility isolation and pointing study

NASA Technical Reports Server (NTRS)

Hibble, William; Allen, Terry; Jackson, Louis; Medbery, James; Self, Richard

1988-01-01

The Astrometric Telescope Facility (ATF), an optical telescope designed to detect extrasolar planetary systems, is scheduled to be a major user of the Space Station's Payload Pointing System (PPS). However, because the ATF has such a stringent pointing stability specification and requires + or - 180 deg roll about its line of sight, mechanisms to enhance the basic PPS capability are required. The ATF pointing performance achievable by the addition of a magnetic isolation and pointing system (MIPS) between the PPS upper gimbal and the ATF, and separately, by the addition of a passive isolation system between the Space Station and the PPS base was investigated. The candidate MIPS can meet the ATF requirements in the presence of a 0.01 g disturbance. It fits within the available annular region between the PPS and the ATF while meeting power and weight limitations and providing the required roll motion, payload data and power services. By contrast, the passive base isolator system must have an unrealistically low isolation bandwidth on all axes to meet ATF pointing requirements and does not provide roll about the line of sight.

Ten Year Study of the Stringently Defined Otitis Prone Child in Rochester, NY

PubMed Central

Pichichero, Michael E.

2016-01-01

This review summarizes a prospective, longitudinal 10-year study in Rochester NY with virtually every clinically diagnosed acute otitis media (AOM) confirmed by bacterial culture of middle ear fluid. Children experiencing 3 episodes within 6 months or 4 episodes in 12 months were considered stringently-defined otitis prone (sOP). We found stringent diagnosis compared with clinical diagnosis reduced the frequency of children meeting the OP definition from 27% to 6% resulting in 14.8% and 2.4% receiving tympanostomy tubes, respectively. Significantly more often RSV infection led to AOM in sOP than non-otitis prone (NOP) children that correlated with diminished total RSV-specific serum IgG. sOP children produced low levels of antibody to Streptococcus pneumoniae and Haemophilus influenzae candidate vaccine protein antigens and to routine pediatric vaccines. sOP children generated significantly fewer memory B cells, functional and memory T cells to otopathogens following NP colonization and AOM than NOP children and they had defects in antigen presenting cells. PMID:27273691

78 FR 20039 - Reportable Events and Certain Other Notification Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

...'' test and four other criteria designed to measure various aspects of financial soundness. The credit... controlled group changes. Like section 4043, the reportable events regulation generally requires post-event... available for plans that could meet one of two funding tests that would be more stringent than those...

FY 2002 Pollution Prevention/Compliance, Acquisition and Technology Division Annual Report

DTIC Science & Technology

2003-03-03

will be better able to preserve readiness, save money and avoid bad decisions by knowing which alternative cleaning products meet its stringent...partnership with commodity managers, USAEC and ATC are leading an initiative to compre- hensively test several cleaning products and gather data the Army

Heavy-Duty Vehicle Thermal Management | Transportation Research | NREL

Science.gov Websites

Heavy-Duty Vehicle Thermal Management Heavy-Duty Vehicle Thermal Management Infrared image of a and meet more stringent idling regulations. NREL's HDV thermal management program, CoolCab, focuses on thermal management technologies undergo assessment at NREL's Vehicle Testing and Integration Facility test

Fixed-Abrasive Grinding of Thin-Film Recording Heads Final Report CRADA No. TC-0498-93

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaedel, K. L.; Newman, C.

The goals of this project were (1) to significantly reduce the cost of manufacturing thin-film recording heads for magnetic storage media and (2) to meet the stringent dimensional tolerances required for heads in the next generation high-density disc drives.

Live, Online Short-Courses: A Case Study of Innovative Teacher Professional Development

ERIC Educational Resources Information Center

Marrero, Meghan E.; Woodruff, Karen A.; Schuster, Glen S.; Riccio, Jessica Fitzsimons

2010-01-01

Teachers are searching for new venues through which they may meet stringent professional development requirements. Under competitive funding from NASA's (National Aeronautics and Space Administration) Office of Education and the NASA Explorer Schools Project, U.S. Satellite Laboratory, Inc. created a series of live, online, interactive…

A Near-Optimal Distributed QoS Constrained Routing Algorithm for Multichannel Wireless Sensor Networks

PubMed Central

Lin, Frank Yeong-Sung; Hsiao, Chiu-Han; Yen, Hong-Hsu; Hsieh, Yu-Jen

2013-01-01

One of the important applications in Wireless Sensor Networks (WSNs) is video surveillance that includes the tasks of video data processing and transmission. Processing and transmission of image and video data in WSNs has attracted a lot of attention in recent years. This is known as Wireless Visual Sensor Networks (WVSNs). WVSNs are distributed intelligent systems for collecting image or video data with unique performance, complexity, and quality of service challenges. WVSNs consist of a large number of battery-powered and resource constrained camera nodes. End-to-end delay is a very important Quality of Service (QoS) metric for video surveillance application in WVSNs. How to meet the stringent delay QoS in resource constrained WVSNs is a challenging issue that requires novel distributed and collaborative routing strategies. This paper proposes a Near-Optimal Distributed QoS Constrained (NODQC) routing algorithm to achieve an end-to-end route with lower delay and higher throughput. A Lagrangian Relaxation (LR)-based routing metric that considers the “system perspective” and “user perspective” is proposed to determine the near-optimal routing paths that satisfy end-to-end delay constraints with high system throughput. The empirical results show that the NODQC routing algorithm outperforms others in terms of higher system throughput with lower average end-to-end delay and delay jitter. In this paper, for the first time, the algorithm shows how to meet the delay QoS and at the same time how to achieve higher system throughput in stringently resource constrained WVSNs.

Creating an optical spectroscopy system for use in a primary care clinical setting (Conference Presentation)

NASA Astrophysics Data System (ADS)

Eshein, Adam; Nguyen, The-Quyen; Radosevich, Andrew J.; Gould, Bradley; Wu, Wenli; Konda, Vani; Yang, Leslie W.; Koons, Ann; Feder, Seth; Valuckaite, Vesta; Roy, Hemant K.; Backman, Vadim

2016-03-01

While there are a plethora of in-vivo spectroscopic techniques that have demonstrated the ability to detect a number of diseases in research trials, very few techniques have successfully become a fully realized clinical technology. This is primarily due to the stringent demands on a clinical device for widespread implementation. Some of these demands include: simple operation requiring minimal or no training, safe for in-vivo patient use, no disruption to normal clinic workflow, tracking of system performance, warning for measurement abnormality, and meeting all FDA guidelines for medical use. Previously, our group developed a fiber optic probe-based optical sensing technique known as low-coherence enhanced backscattering spectroscopy (LEBS) to quantify tissue ultrastructure in-vivo. Now we have developed this technique for the application of prescreening patients for colonoscopy in a primary care (PC) clinical setting. To meet the stringent requirements for a viable medical device used in a PC clinical setting, we developed several novel components including an automated calibration tool, optical contact sensor for signal acquisition, and a contamination sensor to identify measurements which have been affected by debris. The end result is a state-of-the-art medical device that can be realistically used by a PC physician to assess a person's risk for harboring colorectal precancerous lesions. The pilot study of this system shows great promise with excellent stability and accuracy in identifying high-risk patients. While this system has been designed and optimized for our specific application, the system and design concepts are universal to most in-vivo fiber optic based spectroscopic techniques.

Diffraction based overlay metrology for α-carbon applications

NASA Astrophysics Data System (ADS)

Saravanan, Chandra Saru; Tan, Asher; Dasari, Prasad; Goelzer, Gary; Smith, Nigel; Woo, Seouk-Hoon; Shin, Jang Ho; Kang, Hyun Jae; Kim, Ho Chul

2008-03-01

Applications that require overlay measurement between layers separated by absorbing interlayer films (such as α- carbon) pose significant challenges for sub-50nm processes. In this paper scatterometry methods are investigated as an alternative to meet these stringent overlay metrology requirements. In this article, a spectroscopic Diffraction Based Overlay (DBO) measurement technique is used where registration errors are extracted from specially designed diffraction targets. DBO measurements are performed on detailed set of wafers with varying α-carbon (ACL) thicknesses. The correlation in overlay values between wafers with varying ACL thicknesses will be discussed. The total measurement uncertainty (TMU) requirements for these layers are discussed and the DBO TMU results from sub-50nm samples are reviewed.

Hologram interferometry in automotive component vibration testing

NASA Astrophysics Data System (ADS)

Brown, Gordon M.; Forbes, Jamie W.; Marchi, Mitchell M.; Wales, Raymond R.

1993-02-01

An ever increasing variety of automotive component vibration testing is being pursued at Ford Motor Company, U.S.A. The driving force for use of hologram interferometry in these tests is the continuing need to design component structures to meet more stringent functional performance criteria. Parameters such as noise and vibration, sound quality, and reliability must be optimized for the lightest weight component possible. Continually increasing customer expectations and regulatory pressures on fuel economy and safety mandate that vehicles be built from highly optimized components. This paper includes applications of holographic interferometry for powertrain support structure tuning, body panel noise reduction, wiper system noise and vibration path analysis, and other vehicle component studies.

Electrophoresis for biological production

NASA Technical Reports Server (NTRS)

Mccreight, L. R.

1977-01-01

Preparative electrophoresis may provide a unique method for meeting ever more stringent purity requirements. Prolonged near zero gravity in space may permit the operation of preparative electrophoresis equipment with 100 times greater throughput than is currently available. Some experiments with influenza Virus Antigen, Erythropoietin and Antihemophaliac Factor, along with process and economic projections, are briefly reviewed.

VEHICLE MASS REDUCTION STUDY | Science Inventory ...

EPA Pesticide Factsheets

Analysis of the potential to reduce light-duty vehicle mass through the application of low density or high strength materials, component consolidation, and changes to vehicle architecture. Find a holistic vehicle design approach that establishes a potential path for future feasible vehicle mass reduction in light-duty vehicles to meet more stringent GHG and Fuel Economy Standards.

Small Body Landing Accuracy Using In-Situ Navigation

NASA Technical Reports Server (NTRS)

Bhaskaran, Shyam; Nandi, Sumita; Broschart, Stephen; Wallace, Mark; Olson, Corwin; Cangahuala, L. Alberto

2011-01-01

Spacecraft landings on small bodies (asteroids and comets) can require target accuracies too stringent to be met using ground-based navigation alone, especially if specific landing site requirements must be met for safety or to meet science goals. In-situ optical observations coupled with onboard navigation processing can meet the tighter accuracy requirements to enable such missions. Recent developments in deep space navigation capability include a self-contained autonomous navigation system (used in flight on three missions) and a landmark tracking system (used experimentally on the Japanese Hayabusa mission). The merging of these two technologies forms a methodology to perform autonomous onboard navigation around small bodies. This paper presents an overview of these systems, as well as the results from Monte Carlo studies to quantify the achievable landing accuracies by using these methods. Sensitivity of the results to variations in spacecraft maneuver execution error, attitude control accuracy and unmodeled forces are examined. Cases for two bodies, a small asteroid and on a mid-size comet, are presented.

Next Generation P-Band Planetary Synthetic Aperture Radar

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Carter, Lynn; Lu, Dee Pong Daniel

2016-01-01

The Space Exploration Synthetic Aperture Radar (SESAR) is an advanced P-band beamforming radar instrument concept to enable a new class of observations suitable to meet Decadal Survey science goals for planetary exploration. The radar operates at full polarimetry and fine (meter scale) resolution, and achieves beam agility through programmable waveform generation and digital beamforming. The radar architecture employs a novel low power, lightweight design approach to meet stringent planetary instrument requirements. This instrument concept has the potential to provide unprecedented surface and near- subsurface measurements applicable to multiple DecadalSurvey Science Goals.

Next Generation P-Band Planetary Synthetic Aperture Radar

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Carter, Lynn; Lu, Dee Pong Daniel

2017-01-01

The Space Exploration Synthetic Aperture Radar (SESAR) is an advanced P-band beamforming radar instrument concept to enable a new class of observations suitable to meet Decadal Survey science goals for planetary exploration. The radar operates at full polarimetry and fine (meter scale) resolution, and achieves beam agility through programmable waveform generation and digital beamforming. The radar architecture employs a novel low power, lightweight design approach to meet stringent planetary instrument requirements. This instrument concept has the potential to provide unprecedented surface and near- subsurface measurements applicable to multiple Decadal Survey Science Goals.

Model Performance of Water-Current Meters

USGS Publications Warehouse

Fulford, J.M.; ,

2002-01-01

The measurement of discharge in natural streams requires hydrographers to use accurate water-current meters that have consistent performance among meters of the same model. This paper presents the results of an investigation into the performance of four models of current meters - Price type-AA, Price pygmy, Marsh McBirney 2000 and Swoffer 2100. Tests for consistency and accuracy for six meters of each model are summarized. Variation of meter performance within a model is used as an indicator of consistency, and percent velocity error that is computed from a measured reference velocity is used as an indicator of meter accuracy. Velocities measured by each meter are also compared to the manufacturer's published or advertised accuracy limits. For the meters tested, the Price models werer found to be more accurate and consistent over the range of test velocities compared to the other models. The Marsh McBirney model usually measured within its accuracy specification. The Swoffer meters did not meet the stringent Swoffer accuracy limits for all the velocities tested.

Inertial Navigation System for India's Reusable Launch Vehicle-Technology Demonstrator (RLV-TD HEX) Mission

NASA Astrophysics Data System (ADS)

Umadevi, P.; Navas, A.; Karuturi, Kesavabrahmaji; Shukkoor, A. Abdul; Kumar, J. Krishna; Sreekumar, Sreejith; Basim, A. Mohammed

2017-12-01

This work presents the configuration of Inertial Navigation System (INS) used in India's Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) Program. In view of the specific features and requirements of the RLV-TD, specific improvements and modifications were required in the INS. A new system was designed, realised and qualified meeting the mission requirements of RLV-TD, at the same time taking advantage of the flight heritage attained in INS through various Launch vehicle Missions of the country. The new system has additional redundancy in acceleration channel, in-built inclinometer based bias update scheme for acceleration channels and sign conventions as employed in an aircraft. Data acquisition in micro cycle periodicity (10 ms) was incorporated which was required to provide rate and attitude information at higher sampling rate for ascent phase control. Provision was incorporated for acquisition of rate and acceleration data with high resolution for aerodynamic characterisation and parameter estimation. GPS aided navigation scheme was incorporated to meet the stringent accuracy requirements of the mission. Navigation system configuration for RLV-TD, specific features incorporated to meet the mission requirements, various tests carried out and performance during RLV-TD flight are highlighted.

Conceptual design of a coherent optical system of modular imaging collectors (COSMIC). [telescope array deployed by space shuttle in 1990's

NASA Technical Reports Server (NTRS)

Nein, M. E.; Davis, B. G.

1982-01-01

The Coherent Optical System of Modular Imaging Collectors (COSMIC) is the design concept for a phase-coherent optical telescope array that may be placed in earth orbit by the Space Shuttle in the 1990s. The initial system module is a minimum redundancy array whose photon collecting area is three times larger than that of the Space Telescope, and possesses a one-dimensional resoution of better than 0.01 arcsec in the visible range. Thermal structural requirements are assessed. Although the coherent beam combination requirements will be met by an active control system, the COSMIC structural/thermal design must meet more stringent performance criteria than even those of the Space Telescope.

Cryogenic Evaluation of an Advanced DC/DC Converter Module for Deep Space Applications

NASA Technical Reports Server (NTRS)

Elbuluk, Malik E.; Hammoud, Ahmad; Gerber, Scott S.; Patterson, Richard

2003-01-01

DC/DC converters are widely used in power management, conditioning, and control of space power systems. Deep space applications require electronics that withstand cryogenic temperature and meet a stringent radiation tolerance. In this work, the performance of an advanced, radiation-hardened (rad-hard) commercial DC/DC converter module was investigated at cryogenic temperatures. The converter was investigated in terms of its steady state and dynamic operations. The output voltage regulation, efficiency, terminal current ripple characteristics, and output voltage response to load changes were determined in the temperature range of 20 to -140 C. These parameters were obtained at various load levels and at different input voltages. The experimental procedures along with the results obtained on the investigated converter are presented and discussed.

Design and experimental validation of a flutter suppression controller for the active flexible wing

NASA Technical Reports Server (NTRS)

Waszak, Martin R.; Srinathkumar, S.

1992-01-01

The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and extensive simulation based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite modeling errors in predicted flutter dynamic pressure and flutter frequency. The flutter suppression controller was also successfully operated in combination with another controller to perform flutter suppression during rapid rolling maneuvers.

Development of Turbulence-Measuring Equipment

NASA Technical Reports Server (NTRS)

Kovasznay, Leslie S G

1954-01-01

Hot wire turbulence-measuring equipment has been developed to meet the more stringent requirements involved in the measurement of fluctuations in flow parameters at supersonic velocities. The higher mean speed necessitates the resolution of higher frequency components than at low speed, and the relatively low turbulence level present at supersonic speed makes necessary an improved noise level for the equipment. The equipment covers the frequency range from 2 to about 70,000 cycles per second. Constant-current operation is employed. Compensation for hot-wire lag is adjusted manually using square-wave testing to indicate proper setting. These and other features make the equipment adaptable to all-purpose turbulence work with improved utility and accuracy over that of older types of equipment. Sample measurements are given to demonstrate the performance.

Diving into Data: Developing the Capacity for Data Literacy in Teacher Education

ERIC Educational Resources Information Center

Dunlap, Karen; Piro, Jody S.

2016-01-01

Educators by definition are now required to utilize a variety of student data to shape the decisions they make and design the lessons they teach. As accountability standards become more stringent and as teachers face increasingly diverse student populations within their classrooms, they often struggle to adequately meet the needs of all learners.…

Early decision framework for integrating sustainable risk management for complex remediation sites: Drivers, barriers, and performance metrics.

PubMed

Harclerode, Melissa A; Macbeth, Tamzen W; Miller, Michael E; Gurr, Christopher J; Myers, Teri S

2016-12-15

As the environmental remediation industry matures, remaining sites often have significant underlying technical challenges and financial constraints. More often than not, significant remediation efforts at these "complex" sites have not achieved stringent, promulgated cleanup goals. Decisions then have to be made about whether and how to commit additional resources towards achieving those goals, which are often not achievable nor required to protect receptors. Guidance on cleanup approaches focused on evaluating and managing site-specific conditions and risks, rather than uniformly meeting contaminant cleanup criteria in all media, is available to aid in this decision. Although these risk-based cleanup approaches, such as alternative endpoints and adaptive management strategies, have been developed, they are under-utilized due to environmental, socio-economic, and risk perception barriers. Also, these approaches are usually implemented late in the project life cycle after unsuccessful remedial attempts to achieve stringent cleanup criteria. In this article, we address these barriers by developing an early decision framework to identify if site characteristics support sustainable risk management, and develop performance metrics and tools to evaluate and implement successful risk-based cleanup approaches. In addition, we address uncertainty and risk perception challenges by aligning risk-based cleanup approaches with the concepts of risk management and sustainable remediation. This approach was developed in the context of lessons learned from implementing remediation at complex sites, but as a framework can, and should, be applied to all sites undergoing remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prescription practice of biological drugs in rheumatoid arthritis during the first 3 years of post-marketing use in Denmark and Norway: criteria are becoming less stringent

PubMed Central

Hjardem, E; Hetland, M; Ostergaard, M; Krogh, N; Kvien, T

2005-01-01

Objective: To investigate changes in prescription practice during the first 3 years of post-marketing use of biological drugs, and to determine the proportion of patients who would not have received tumour necrosis factor (TNF) blocking agents if the prescription guidelines of the UK and the Netherlands had been applied. Methods: Patients with rheumatoid arthritis (RA) receiving TNF blocking agents from Denmark (n = 823, median age 56.0, 72.2% women) and Norway (n = 371, median age 52.5, 75.4% women) were studied. Prescription guidelines in the UK and the Netherlands were applied to the data. Results: Baseline disease activity and number of previous DMARDs declined significantly during the 3 years (median baseline DAS28 decreased from 5.8 to 5.2 in Denmark (p<0.001) and from 6.0 to 5.6 in Norway (p<0.01)). 47.9% and 41.3% of the Norwegian and Danish patients, respectively, did not meet the UK criteria for using TNF blocking agents, and 10.5% and 5.7% did not meet the Dutch criteria. Conclusion: Danish and Norwegian prescription practices of biological treatments in RA were similar, and became less stringent from 2000 to 2003. Prescriptions agreed well with the Dutch guidelines, but almost half the patients did not meet the UK guidelines. PMID:15640272

Antennas for 20/30 GHz and beyond

NASA Technical Reports Server (NTRS)

Chen, C. Harry; Wong, William C.; Hamada, S. Jim

1989-01-01

Antennas of 20/30 GHz and higher frequency, due to the small wavelength, offer capabilities for many space applications. With the government-sponsored space programs (such as ACTS) in recent years, the industry has gone through the learning curve of designing and developing high-performance, multi-function antennas in this frequency range. Design and analysis tools (such as the computer modelling used in feedhorn design and reflector surface and thermal distortion analysis) are available. The components/devices (such as BFN's, weight modules, feedhorns and etc.) are space-qualified. The manufacturing procedures (such as reflector surface control) are refined to meet the stringent tolerance accompanying high frequencies. The integration and testing facilities (such as Near-Field range) also advance to facilitate precision assembling and performance verification. These capabilities, essential to the successful design and development of high-frequency spaceborne antennas, shall find more space applications (such as ESGP) than just communications.

Passive isolation/damping system for the Hubble space telescope reaction wheels

NASA Technical Reports Server (NTRS)

Hasha, Martin D.

1987-01-01

NASA's Hubble Space Telescope contain large, diffraction limited optics with extraordinary resolution and performance for surpassing existing observatories. The need to reduce structural borne vibration and resultant optical jitter from critical Pointing Control System components, Reaction Wheels, prompted the feasibility investigation and eventual development of a passive isolation system. Alternative design concepts considered were required to meet a host of stringent specifications and pass rigid tests to be successfully verified and integrated into the already built flight vehicle. The final design employs multiple arrays of fluid damped springs that attenuate over a wide spectrum, while confining newly introduced resonances to benign regions of vehicle dynamic response. Overall jitter improvement of roughly a factor of 2 to 3 is attained with this system. The basis, evolution, and performance of the isolation system, specifically discussing design concepts considered, optimization studies, development lessons learned, innovative features, and analytical and ground test verified results are presented.

Stringent DDI-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

PubMed

Zhou, Hufeng; Rezaei, Javad; Hugo, Willy; Gao, Shangzhi; Jin, Jingjing; Fan, Mengyuan; Yong, Chern-Han; Wozniak, Michal; Wong, Limsoon

2013-01-01

H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are very important information to illuminate the infection mechanism of M. tuberculosis H37Rv. But current H. sapiens-M. tuberculosis H37Rv PPI data are very scarce. This seriously limits the study of the interaction between this important pathogen and its host H. sapiens. Computational prediction of H. sapiens-M. tuberculosis H37Rv PPIs is an important strategy to fill in the gap. Domain-domain interaction (DDI) based prediction is one of the frequently used computational approaches in predicting both intra-species and inter-species PPIs. However, the performance of DDI-based host-pathogen PPI prediction has been rather limited. We develop a stringent DDI-based prediction approach with emphasis on (i) differences between the specific domain sequences on annotated regions of proteins under the same domain ID and (ii) calculation of the interaction strength of predicted PPIs based on the interacting residues in their interaction interfaces. We compare our stringent DDI-based approach to a conventional DDI-based approach for predicting PPIs based on gold standard intra-species PPIs and coherent informative Gene Ontology terms assessment. The assessment results show that our stringent DDI-based approach achieves much better performance in predicting PPIs than the conventional approach. Using our stringent DDI-based approach, we have predicted a small set of reliable H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. We also analyze the H. sapiens-M. tuberculosis H37Rv PPIs predicted by our stringent DDI-based approach using cellular compartment distribution analysis, functional category enrichment analysis and pathway enrichment analysis. The analyses support the validity of our prediction result. Also, based on an analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent DDI-based approach, we have discovered some important properties of domains involved in host-pathogen PPIs. We find that both host and pathogen proteins involved in host-pathogen PPIs tend to have more domains than proteins involved in intra-species PPIs, and these domains have more interaction partners than domains on proteins involved in intra-species PPI. The stringent DDI-based prediction approach reported in this work provides a stringent strategy for predicting host-pathogen PPIs. It also performs better than a conventional DDI-based approach in predicting PPIs. We have predicted a small set of accurate H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxwell, S.; Berger, D.; Zuluaga, M.

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent. CARB researchers have found that most new high performance, multifamily housing in the Northeast use one of four strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unitmore » HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. Product performance data are based on laboratory tests, but there is no guarantee that those conditions will exist consistently in the finished building. In this research project, CARB evaluated the four ventilation strategies in the field to validate system performance.« less

InAs/GaInSb strained layer superlattice as an infrared detector material: an overview

NASA Astrophysics Data System (ADS)

Johnson, Jeffrey L.

2000-04-01

The investigation of the InAs/Ga1-xInxSb strained layer superlattice (SLS) has been largely motivated by the promise of overcoming limitations of current mature high-performance IR detectors, such as those using HgCdTe and extrinsic silicon. It also offers fundamentally superior performance over other newly emerging III-V bandgap- engineered materials such as QWIPs. The inherent properties of the InAs/GaInSb SLS have identified it as an attractive alternative for niche VLWIR applications requiring high performance under low backgrounds at operating temperatures > 40K. If this material system proves to meet the stringent demands of VLWIR applications, it will most certainly play a significant role as an alternative materials for photovoltaic focal pane arrays operating in the LWIR and MWIR regimes as well. This paper is an overview of SLS technology development, and focuses on critical development needs as seen from the perspective of the IR detector industry.

Challenges in Aeropropulsion

NASA Technical Reports Server (NTRS)

Campbell, Donald C.

1995-01-01

Aeropropulsion technologies must progress to satisfy increasingly stringent global environmental requirements with economically viable air transportation systems. In this paper, key propulsion technologies to meet future needs are identified and the associated challenges are briefly discussed. Also discussed are NASA's vision, NASA's changing role in meeting today's challenge of a shrinking research budget, and propulsion technology impacts on the environment and air transport economics. Critical aeropropulsion technology drivers are identified and their impact evaluated. The aviation industry is critical to the nation's economy, job creation, and national security. NASA's advanced aeropropulsion technology programs and their relation to the aviation industry are discussed.

Optimized Biasing of Pump Laser Diodes in a Highly Reliable Metrology Source for Long-Duration Space Missions

NASA Technical Reports Server (NTRS)

Poberezhskiy, Ilya; Chang, Daniel; Erlig, Hernan

2011-01-01

Non Planar Ring Oscillator (NPRO) lasers are highly attractive for metrology applications. NPRO reliability for prolonged space missions is limited by reliability of 808 nm pump diodes. Combined laser farm aging parameter allows comparing different bias approaches. Monte-Carlo software developed to calculate the reliability of laser pump architecture, perform parameter sensitivity studies To meet stringent Space Interferometry Mission (SIM) Lite lifetime reliability / output power requirements, we developed a single-mode Laser Pump Module architecture that: (1) provides 2 W of power at 808 nm with >99.7% reliability for 5.5 years (2) consists of 37 de-rated diode lasers operating at -5C, with outputs combined in a very low loss 37x1 all-fiber coupler

Gold coatings for cube-corner retro-reflectors

NASA Astrophysics Data System (ADS)

Dligatch, Svetlana; Gross, Mark; Netterfield, Roger P.; Pereira, Nathan; Platt, Benjamin C.; Nemati, Bijan

2005-09-01

The Space Interferometry Mission (SIM) PlanetQuest is managed by the Jet Propulsion Laboratory for the National Aeronautics and Space Administration. SIM requires, among other things, high precision double cube-corner retroreflectors. A test device has recently been fabricated for this project with demanding specifications on the optical surfaces and gold reflective coatings. Several gold deposition techniques were examined to meet the stringent specifications on uniformity, optical properties, micro-roughness and surface quality. We report on a comparative study of optical performance of gold films deposited by resistive and e-beam pvaporation, including measurements of the scattering from the coated surfaces. The effects of oxygen bombardment and titanium under-layer on optical properties and adhesion were evaluated. The influence of surface preparation on the optical properties was examined also.

Transmission of multiplexed video signals in multimode optical fiber systems

NASA Technical Reports Server (NTRS)

White, Preston, III

1988-01-01

Kennedy Space Center has the need for economical transmission of two multiplexed video signals along multimode fiberoptic systems. These systems must span unusual distances and must meet RS-250B short-haul standards after reception. Bandwidth is a major problem and studies of the installed fibers, available LEDs and PINFETs led to the choice of 100 MHz as the upper limit for the system bandwidth. Optical multiplexing and digital transmission were deemed inappropriate. Three electrical multiplexing schemes were chosen for further study. Each of the multiplexing schemes included an FM stage to help meet the stringent S/N specification. Both FM and AM frequency division multiplexing methods were investigated theoretically and these results were validated with laboratory tests. The novel application of quadrature amplitude multiplexing was also considered. Frequency division multiplexing of two wideband FM video signal appears the most promising scheme although this application requires high power highly linear LED transmitters. Futher studies are necessary to determine if LEDs of appropriate quality exist and to better quantify performance of QAM in this application.

Risk management for the Space Exploration Initiative

NASA Technical Reports Server (NTRS)

Buchbinder, Ben

1993-01-01

Probabilistic Risk Assessment (PRA) is a quantitative engineering process that provides the analytic structure and decision-making framework for total programmatic risk management. Ideally, it is initiated in the conceptual design phase and used throughout the program life cycle. Although PRA was developed for assessment of safety, reliability, and availability risk, it has far greater application. Throughout the design phase, PRA can guide trade-off studies among system performance, safety, reliability, cost, and schedule. These studies are based on the assessment of the risk of meeting each parameter goal, with full consideration of the uncertainties. Quantitative trade-off studies are essential, but without full identification, propagation, and display of uncertainties, poor decisions may result. PRA also can focus attention on risk drivers in situations where risk is too high. For example, if safety risk is unacceptable, the PRA prioritizes the risk contributors to guide the use of resources for risk mitigation. PRA is used in the Space Exploration Initiative (SEI) Program. To meet the stringent requirements of the SEI mission, within strict budgetary constraints, the PRA structure supports informed and traceable decision-making. This paper briefly describes the SEI PRA process.

Stringent DDI-based Prediction of H. sapiens-M. tuberculosis H37Rv Protein-Protein Interactions

PubMed Central

2013-01-01

Background H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are very important information to illuminate the infection mechanism of M. tuberculosis H37Rv. But current H. sapiens-M. tuberculosis H37Rv PPI data are very scarce. This seriously limits the study of the interaction between this important pathogen and its host H. sapiens. Computational prediction of H. sapiens-M. tuberculosis H37Rv PPIs is an important strategy to fill in the gap. Domain-domain interaction (DDI) based prediction is one of the frequently used computational approaches in predicting both intra-species and inter-species PPIs. However, the performance of DDI-based host-pathogen PPI prediction has been rather limited. Results We develop a stringent DDI-based prediction approach with emphasis on (i) differences between the specific domain sequences on annotated regions of proteins under the same domain ID and (ii) calculation of the interaction strength of predicted PPIs based on the interacting residues in their interaction interfaces. We compare our stringent DDI-based approach to a conventional DDI-based approach for predicting PPIs based on gold standard intra-species PPIs and coherent informative Gene Ontology terms assessment. The assessment results show that our stringent DDI-based approach achieves much better performance in predicting PPIs than the conventional approach. Using our stringent DDI-based approach, we have predicted a small set of reliable H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. We also analyze the H. sapiens-M. tuberculosis H37Rv PPIs predicted by our stringent DDI-based approach using cellular compartment distribution analysis, functional category enrichment analysis and pathway enrichment analysis. The analyses support the validity of our prediction result. Also, based on an analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent DDI-based approach, we have discovered some important properties of domains involved in host-pathogen PPIs. We find that both host and pathogen proteins involved in host-pathogen PPIs tend to have more domains than proteins involved in intra-species PPIs, and these domains have more interaction partners than domains on proteins involved in intra-species PPI. Conclusions The stringent DDI-based prediction approach reported in this work provides a stringent strategy for predicting host-pathogen PPIs. It also performs better than a conventional DDI-based approach in predicting PPIs. We have predicted a small set of accurate H. sapiens-M. tuberculosis H37Rv PPIs which could be very useful for a variety of related studies. PMID:24564941

Prototyping Control and Data Acquisition for the ITER Neutral Beam Test Facility

NASA Astrophysics Data System (ADS)

Luchetta, Adriano; Manduchi, Gabriele; Taliercio, Cesare; Soppelsa, Anton; Paolucci, Francesco; Sartori, Filippo; Barbato, Paolo; Breda, Mauro; Capobianco, Roberto; Molon, Federico; Moressa, Modesto; Polato, Sandro; Simionato, Paola; Zampiva, Enrico

2013-10-01

The ITER Neutral Beam Test Facility will be the project's R&D facility for heating neutral beam injectors (HNB) for fusion research operating with H/D negative ions. Its mission is to develop technology to build the HNB prototype injector meeting the stringent HNB requirements (16.5 MW injection power, -1 MeV acceleration energy, 40 A ion current and one hour continuous operation). Two test-beds will be built in sequence in the facility: first SPIDER, the ion source test-bed, to optimize the negative ion source performance, second MITICA, the actual prototype injector, to optimize ion beam acceleration and neutralization. The SPIDER control and data acquisition system is under design. To validate the main architectural choices, a system prototype has been assembled and performance tests have been executed to assess the prototype's capability to meet the control and data acquisition system requirements. The prototype is based on open-source software frameworks running under Linux. EPICS is the slow control engine, MDSplus is the data handler and MARTe is the fast control manager. The prototype addresses low and high-frequency data acquisition, 10 kS/s and 10 MS/s respectively, camera image acquisition, data archiving, data streaming, data retrieval and visualization, real time fast control with 100 μs control cycle and supervisory control.

A microdisplay-based HUD for automotive applications: Backplane design, planarization, and optical implementation

NASA Astrophysics Data System (ADS)

Schuck, Miller Harry

Automotive head-up displays require compact, bright, and inexpensive imaging systems. In this thesis, a compact head-up display (HUD) utilizing liquid-crystal-on-silicon microdisplay technology is presented from concept to implementation. The thesis comprises three primary areas of HUD research: the specification, design and implementation of a compact HUD optical system, the development of a wafer planarization process to enhance reflective device brightness and light immunity and the design, fabrication and testing of an inexpensive 640 x 512 pixel active matrix backplane intended to meet the HUD requirements. The thesis addresses the HUD problem at three levels, the systems level, the device level, and the materials level. At the systems level, the optical design of an automotive HUD must meet several competing requirements, including high image brightness, compact packaging, video-rate performance, and low cost. An optical system design which meets the competing requirements has been developed utilizing a fully-reconfigurable reflective microdisplay. The design consists of two optical stages, the first a projector stage which magnifies the display, and a second stage which forms the virtual image eventually seen by the driver. A key component of the optical system is a diffraction grating/field lens which forms a large viewing eyebox while reducing the optical system complexity. Image quality biocular disparity and luminous efficacy were analyzed and results of the optical implementation are presented. At the device level, the automotive HUD requires a reconfigurable, video-rate, high resolution image source for applications such as navigation and night vision. The design of a 640 x 512 pixel active matrix backplane which meets the requirements of the HUD is described. The backplane was designed to produce digital field sequential color images at video rates utilizing fast switching liquid crystal as the modulation layer. The design methodology is discussed, and the example of a clock generator is described from design to implementation. Electrical and optical test results of the fabricated backplane are presented. At the materials level, a planarization method was developed to meet the stringent brightness requirements of automotive HUD's. The research efforts described here have resulted in a simple, low cost post-processing method for planarizing microdisplay substrates based on a spin-cast polymeric resin, benzocyclobutene (BCB). Six- fold reductions in substrate step height were accomplished with a single coating. Via masking and dry etching methods were developed. High reflectivity metal was deposited and patterned over the planarized substrate to produce high aperture pixel mirrors. The process is simple, rapid, and results in microdisplays better able to meet the stringent requirements of high brightness display systems. Methods and results of the post- processing are described.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meinke, Rainer B.; Goodzeit, Carl L.; Ball, Millicent J.

This research project advanced the development of reliable, cost-effective arrays of superconducting quadrupole magnets for use in multi-beam inertial fusion accelerators. The field in each array cell must be identical and meet stringent requirements for field quality and strength. An optimized compact array design using flat double-layer pancake coils was developed. Analytical studies of edge termination methods showed that it is feasible to meet the requirements for field uniformity in all cells and elimination of stray external field in several ways: active methods that involve placement of field compensating coils on the periphery of the array or a passive methodmore » that involves use of iron shielding.« less

A Viking satellite orbit trim strategy

NASA Technical Reports Server (NTRS)

Hintz, G. R.

1971-01-01

One strategy is submitted for meeting the varied and stringent requirements of the Viking Project on the control of the satellite orbit to obtain reconnaissance and to prepare for lander release. To satisfy these requirements, different orbit trim maneuver strategies were developed for two typical Viking missions. In addition, a summary of recent numerical results is included to show that this strategy satisfies the mission requirements which have been identified.

Development of hermetic electrical connectors for SSC spool pieces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kountanis, B.; Kalny, L.

1993-05-01

The Superconducting Super Collider ring is about 54 miles (87 km circumference) and primarily includes a series of magnets. Spool piece assemblies are interspaced in the ring at predetermined intervals to provide specific functions such as cryogenic interfaces, vacuum interface, magnet power, magnet power dump, quench heater power, and special instrumentation. Electrical connectors serve as interfaces for instrumentation and quench heater circuits. These connectors have to meet stringent requirements.

Reducing secondary organic aerosol formation from gasoline vehicle exhaust

PubMed Central

Zhao, Yunliang; Saleh, Rawad; Presto, Albert A.; Gordon, Timothy D.; Drozd, Greg T.; Goldstein, Allen H.; Robinson, Allen L.

2017-01-01

On-road gasoline vehicles are a major source of secondary organic aerosol (SOA) in urban areas. We investigated SOA formation by oxidizing dilute, ambient-level exhaust concentrations from a fleet of on-road gasoline vehicles in a smog chamber. We measured less SOA formation from newer vehicles meeting more stringent emissions standards. This suggests that the natural replacement of older vehicles with newer ones that meet more stringent emissions standards should reduce SOA levels in urban environments. However, SOA production depends on both precursor concentrations (emissions) and atmospheric chemistry (SOA yields). We found a strongly nonlinear relationship between SOA formation and the ratio of nonmethane organic gas to oxides of nitrogen (NOx) (NMOG:NOx), which affects the fate of peroxy radicals. For example, changing the NMOG:NOx from 4 to 10 ppbC/ppbNOx increased the SOA yield from dilute gasoline vehicle exhaust by a factor of 8. We investigated the implications of this relationship for the Los Angeles area. Although organic gas emissions from gasoline vehicles in Los Angeles are expected to fall by almost 80% over the next two decades, we predict no reduction in SOA production from these emissions due to the effects of rising NMOG:NOx on SOA yields. This highlights the importance of integrated emission control policies for NOx and organic gases. PMID:28630318

Contamination Control Assessment of the World's Largest Space Environment Simulation Chamber

NASA Technical Reports Server (NTRS)

Snyder, Aaron; Henry, Michael W.; Grisnik, Stanley P.; Sinclair, Stephen M.

2012-01-01

The Space Power Facility s thermal vacuum test chamber is the largest chamber in the world capable of providing an environment for space simulation. To improve performance and meet stringent requirements of a wide customer base, significant modifications were made to the vacuum chamber. These include major changes to the vacuum system and numerous enhancements to the chamber s unique polar crane, with a goal of providing high cleanliness levels. The significance of these changes and modifications are discussed in this paper. In addition, the composition and arrangement of the pumping system and its impact on molecular back-streaming are discussed in detail. Molecular contamination measurements obtained with a TQCM and witness wafers during two recent integrated system tests of the chamber are presented and discussed. Finally, a concluding remarks section is presented.

Wear of seal materials used in aircraft propulsion systems

NASA Technical Reports Server (NTRS)

Bill, R. C.; Ludwig, L. P.

1978-01-01

The various types of seal locations in a gas turbine engine are described, and the significance of wear to each type is reviewed. Starting with positive contact shaft seals, existing material selection guidelines are reviewed, and the existing PV (contact pressure X sliding velocity) criteria for selecting seal materials are discussed, along with the theoretical background for these criteria. Examples of wear mechanisms observed to operate in positive contact seals are shown. Design features that can extend the operating capabilities of positive contact seals, including pressure balancing and incorporation of hydrodynamic lift are briefly discussed. It is concluded that, despite the benefits arising from these design features, improved positive contact seal materials from the standpoint of wear, erosion and oxidation resistance will be necessary for further improvements in seal performance and durability, and to meet stringent future challenges.

An analysis of Landsat Thematic Mapper P-Product internal geometry and conformity to earth surface geometry

NASA Technical Reports Server (NTRS)

Bryant, N. A.; Zobrist, A. L.; Walker, R. E.; Gokhman, B.

1985-01-01

Performance requirements regarding geometric accuracy have been defined in terms of end product goals, but until recently no precise details have been given concerning the conditions under which that accuracy is to be achieved. In order to achieve higher spatial and spectral resolutions, the Thematic Mapper (TM) sensor was designed to image in both forward and reverse mirror sweeps in two separate focal planes. Both hardware and software have been augmented and changed during the course of the Landsat TM developments to achieve improved geometric accuracy. An investigation has been conducted to determine if the TM meets the National Map Accuracy Standards for geometric accuracy at larger scales. It was found that TM imagery, in terms of geometry, has come close to, and in some cases exceeded, its stringent specifications.

A spacecraft integrated power/attitude control system

NASA Technical Reports Server (NTRS)

Keckler, C. R.; Jacobs, K. L.

1974-01-01

A study to determine the viability and application of a system capable of performing the dual function of power storage/generation and attitude control has been conducted. Results from the study indicate that an integrated power/attitude control system (IPACS) can satisfy future mission requirements while providing significant savings in weight, volume, and cost over conventional systems. A failure-mode configuration of an IPACS was applied to a shuttle-launched RAM free-flyer and simulated using make-do hardware linked to a hybrid computer. Data from the simulation runs indicate that control interactions resulting from heavy power demands have minimal effect on system control effectiveness. The system was shown to be capable of meeting the stringent pointing requirements of 1 arc-second while operating under the influence of an orbital disturbance environment and during periods of momentum variations imposed by energy transfer requirements.

Seismic isolation of Advanced LIGO: Review of strategy, instrumentation and performance

NASA Astrophysics Data System (ADS)

Matichard, F.; Lantz, B.; Mittleman, R.; Mason, K.; Kissel, J.; Abbott, B.; Biscans, S.; McIver, J.; Abbott, R.; Abbott, S.; Allwine, E.; Barnum, S.; Birch, J.; Celerier, C.; Clark, D.; Coyne, D.; DeBra, D.; DeRosa, R.; Evans, M.; Foley, S.; Fritschel, P.; Giaime, J. A.; Gray, C.; Grabeel, G.; Hanson, J.; Hardham, C.; Hillard, M.; Hua, W.; Kucharczyk, C.; Landry, M.; Le Roux, A.; Lhuillier, V.; Macleod, D.; Macinnis, M.; Mitchell, R.; O'Reilly, B.; Ottaway, D.; Paris, H.; Pele, A.; Puma, M.; Radkins, H.; Ramet, C.; Robinson, M.; Ruet, L.; Sarin, P.; Shoemaker, D.; Stein, A.; Thomas, J.; Vargas, M.; Venkateswara, K.; Warner, J.; Wen, S.

2015-09-01

The new generation of gravitational waves detectors require unprecedented levels of isolation from seismic noise. This article reviews the seismic isolation strategy and instrumentation developed for the Advanced LIGO observatories. It summarizes over a decade of research on active inertial isolation and shows the performance recently achieved at the Advanced LIGO observatories. The paper emphasizes the scientific and technical challenges of this endeavor and how they have been addressed. An overview of the isolation strategy is given. It combines multiple layers of passive and active inertial isolation to provide suitable rejection of seismic noise at all frequencies. A detailed presentation of the three active platforms that have been developed is given. They are the hydraulic pre-isolator, the single-stage internal isolator and the two-stage internal isolator. The architecture, instrumentation, control scheme and isolation results are presented for each of the three systems. Results show that the seismic isolation sub-system meets Advanced LIGO’s stringent requirements and robustly supports the operation of the two detectors.

Energy Efficient Engine (E3) combustion system component technology performance report

NASA Technical Reports Server (NTRS)

Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

1984-01-01

The Energy Efficient Engine (E3) combustor effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent of this effort was to evolve a design that meets the stringent emissions and life goals of the E3, as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this effort was incorporated into the engine combustion hardware design. The advanced engine combustion system was then evaluated in component testing to verify the design intent. What evolved from this effort was an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3.

A mechanistic review on vermifiltration of wastewater: Design, operation and performance.

PubMed

Singh, Rajneesh; Bhunia, Puspendu; Dash, Rajesh R

2017-07-15

With global population explosion, the available water resources are slowly being polluted due to the excessive human interference. To encounter this, it is the need of this hour to find out sustainable pollution remediating technologies to meet the stringent discharge standards for domestic as well as industrial wastewaters. In addition, those techniques should have the capabilities for effective implementation even in developing countries. Based on the available literatures, one such technique, named vermifilter, has been identified which takes care of almost all the sustainable and economical criteria for its effective implementation even in developing countries. The aim of this meta-analysis is to provide a comprehensive review on assessment mechanisms involved, factors affecting the process and performance of vermifiltration under different scenarios. The present review envisages the current state of the knowledge regarding physical, chemical and biological aspects related to the treatment mechanisms and effective functioning of earthworms. This review has also proposed several suggestive plans on its application at any proposed site. Copyright © 2017 Elsevier Ltd. All rights reserved.

On-Orbit Maneuver Calibrations for the Stardust Spacecraft

NASA Technical Reports Server (NTRS)

Nandi, Sumita; Kennedy, Brian; Williams, Kenneth E.; Byrnes, Dennis V.

2006-01-01

The Stardust spacecraft, launched February 7, 1999, successfully delivered its sample return capsule to the Utah Test and Training Range on January 15, 2006. The entry maneuver strategy included a trajectory correction at entry minus 10 days (TCM18) targeted to entry with the inclusion of a final biased fixed direction maneuver at entry minus 29 hours (TCM19). To meet the stringent entry targeting requirements necessary for human safety and capsule integrity, a campaign of maneuver calibrations were undertaken in summers of 2003 and 2005 to improve performance for both maneuvers. The results of the calibration program are reported here. The in-flight calibrations included a series of several turns to various final attitudes via deadband walks about each of the three spacecraft axes, as well as 12 in-place burns with magnitudes between 0.5 and 1.0 m/s, the range initially expected for TCM19. The turn and burn calibrations as well as the performance of TCM 17, 18 and 19 are discussed.

Millimeter-wave MMIC technology for smart weapons

NASA Astrophysics Data System (ADS)

Seashore, Charles R.

1994-12-01

Millimeter wave MMIC component technology has made dramatic progress over the last ten years largely due to funding stimulation received under the ARPA Tri-Service MIMIC program. In several smart weapon systems, MMIC components are now specified as the baseline approach for millimeter wave radar transceiver hardware. Availability of this new frontier in microelectronics has also enabled realization of sensor fusion for multispectral capability to defeat many forms of known countermeasures. The current frequency range for these MMIC-based components is approximately 30 to 100 GHz. In several cases, it has been demonstrated that the MMIC component performance has exceeded that available from hybrid microstrip circuits using selected discrete devices. However, challenges still remain in chip producibility enhancement and cost reduction since many of the essential device structure candidates are themselves emerging technologies with a limited wafer fabrication history and accumulated test databases. It is concluded that smart weapons of the future will rely heavily on advanced microelectronics to satisfy performance requirements as well as meeting stringent packaging and power source constraints.

NIST torsion oscillator viscometer response: Performance on the LeRC active vibration isolation platform

NASA Technical Reports Server (NTRS)

Berg, Robert F.; Grodsinsky, Carlos M.

1992-01-01

Critical point viscosity measurements are limited to their reduced temperature approach to T(sub c) in an Earth bound system, because of density gradients imposed by gravity. Therefore, these classes of experiments have been proposed as good candidates for 'microgravity' science experiments where this limitation is not present. The nature of these viscosity measurements dictate hardware that is sensitive to low frequency excitations. Because of the vibratory acceleration sensitivity of a torsion oscillator viscometer, used to acquire such measurements, a vibration isolation sensitivity test was performed on candidate 'microgravity' hardware to study the possibility of meeting the stringent oscillatory sensitivity requirements of a National Institute of Standards and Technology (NIST) torsion oscillator viscometer. A prototype six degree of freedom active magnetic isolation system, developed at NASA Lewis Research Center, was used as the isolation system. The ambient acceleration levels of the platform were reduced to the noise floor levels of its control sensors, about one microgravity in the 0.1 to 10 Hz bandwidth.

Low Cost High Performance Nanostructured Spectrally Selective Coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Sungho

2017-04-05

Sunlight absorbing coating is a key enabling technology to achieve high-temperature high-efficiency concentrating solar power operation. A high-performance solar absorbing material must simultaneously meet all the following three stringent requirements: high thermal efficiency (usually measured by figure of merit), high-temperature durability, and oxidation resistance. The objective of this research is to employ a highly scalable process to fabricate and coat black oxide nanoparticles onto solar absorber surface to achieve ultra-high thermal efficiency. Black oxide nanoparticles have been synthesized using a facile process and coated onto absorber metal surface. The material composition, size distribution and morphology of the nanoparticle are guidedmore » by numeric modeling. Optical and thermal properties have been both modeled and measured. High temperature durability has been achieved by using nanocomposites and high temperature annealing. Mechanical durability on thermal cycling have also been investigated and optimized. This technology is promising for commercial applications in next-generation high-temperature concentration solar power (CSP) plants.« less

Programming Models for Concurrency and Real-Time

NASA Astrophysics Data System (ADS)

Vitek, Jan

Modern real-time applications are increasingly large, complex and concurrent systems which must meet stringent performance and predictability requirements. Programming those systems require fundamental advances in programming languages and runtime systems. This talk presents our work on Flexotasks, a programming model for concurrent, real-time systems inspired by stream-processing and concurrent active objects. Some of the key innovations in Flexotasks are that it support both real-time garbage collection and region-based memory with an ownership type system for static safety. Communication between tasks is performed by channels with a linear type discipline to avoid copying messages, and by a non-blocking transactional memory facility. We have evaluated our model empirically within two distinct implementations, one based on Purdue’s Ovm research virtual machine framework and the other on Websphere, IBM’s production real-time virtual machine. We have written a number of small programs, as well as a 30 KLOC avionics collision detector application. We show that Flexotasks are capable of executing periodic threads at 10 KHz with a standard deviation of 1.2us and have performance competitive with hand coded C programs.

VETA-1 x ray detection system

NASA Technical Reports Server (NTRS)

Podgorski, W. A.; Flanagan, Kathy A.; Freeman, Mark D.; Goddard, R. G.; Kellogg, Edwin M.; Norton, T. J.; Ouellette, J. P.; Roy, A. G.; Schwartz, Daniel A.

1992-01-01

The alignment and X-ray imaging performance of the Advanced X-ray Astrophysics Facility (AXAF) Verification Engineering Test Article-I (VETA-I) was measured by the VETA-I X-Ray Detection System (VXDS). The VXDS was based on the X-ray detection system utilized in the AXAF Technology Mirror Assembly (TMA) program, upgraded to meet the more stringent requirements of the VETA-I test program. The VXDS includes two types of X-ray detectors: (1) a High Resolution Imager (HRI) which provides X-ray imaging capabilities, and (2) sealed and flow proportional counters which, in conjunction with apertures of various types and precision translation stages, provide the most accurate measurement of VETA-I performance. Herein we give an overview of the VXDS hardware including X-ray detectors, translation stages, apertures, proportional counters and flow counter gas supply system and associated electronics. We also describe the installation of the VXDS into the Marshall Space Flight Center (MSFC) X-Ray Calibration Facility (XRCF). We discuss in detail the design and performance of those elements of the VXDS which have not been discussed elsewhere; translation systems, flow counter gas supply system, apertures and thermal monitoring system.

Diesel fuel detergent additive performance and assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vincent, M.W.; Papachristos, M.J.; Williams, D.

Diesel fuel detergent additives are increasingly linked with high quality automotive diesel fuels. Both in Europe and in the USA, field problems associated with fuel injector coking or fouling have been experienced. In Europe indirect injection (IDI) light duty engines used in passenger cars were affected, while in the USA, a direct injection (DI) engine in heavy duty truck applications experienced field problems. In both cases, a fuel additive detergent performance test has evolved using an engine linked with the original field problem, although engine design modifications employed by the manufacturers have ensured improved operation in service. Increasing awareness ofmore » the potential for injector nozzle coking to cause deterioration in engine performance is coupled with a need to meet ever more stringent exhaust emissions legislation. These two requirements indicate that the use of detergency additives will continue to be associated with high quality diesel fuels. The paper examines detergency performance evaluated in a range of IDI and DI engines and correlates performance in the two most widely recognised test engines, namely the Peugeot 1.9 litre IDI, and Cummins L10 DI engines. 17 refs., 18 figs., 5 tabs.« less

A Superior Kirchhoff Method for Aeroacoustic Noise Prediction: The Ffowcs Williams-Hawkings Equation

NASA Technical Reports Server (NTRS)

Brentner, Kenneth S.

1997-01-01

The prediction of aeroacoustic noise is important; all new aircraft must meet noise certification requirements. Local noise standards can be even more stringent. The NASA noise reduction goal is to reduce perceived noise levels by a factor of two in 10 years. The objective of this viewgraph presentation is to demonstrate the superiority of the FW-H approach over the Kirchoff method for aeroacoustics, both analytically and numerically.

Optical calibration of SNO +

NASA Astrophysics Data System (ADS)

Leming, Edward; SNO+ Collaboration

2015-04-01

Situated 2 km underground in Sudbury, Northern Ontario, the SNO + detector consists of an acrylic sphere 12 m in diameter containing 780 tons of target mass, surrounded by approximately 9,500 PMTs. For SNO, this target mass was heavy water, however the change to SNO + is defined by the change of this target mass to a novel scintillator. With the lower energy threshold, low intrinsic radioactivity levels and the best shielding against muons and cosmogenic activation of all existing neutrino experiments, SNO + will be sensitive to exciting new physics. The experiment will be studying solar, reactor, super nova and geo-neutrinos, though the main purpose of SNO + is the search for neutrinoless double-beta decay of Te-130. To meet the requirements imposed by the physics on detector performance, a detailed optical calibration is needed. Source deployment must be kept to a minimum and eliminated if possible, in order to meet the stringent radiopurity requirements. This led to the development of the Embedded LED/laser Light Injection Entity (ELLIE) system. This talk provides a summary of the upgrades to from SNO to SNO +, discussing the requirements on and methods of optical calibration, focusing on the deployed laserball and ELLIE system.

High performance real-time flight simulation at NASA Langley

NASA Technical Reports Server (NTRS)

Cleveland, Jeff I., II

1994-01-01

In order to meet the stringent time-critical requirements for real-time man-in-the-loop flight simulation, computer processing operations must be deterministic and be completed in as short a time as possible. This includes simulation mathematical model computational and data input/output to the simulators. In 1986, in response to increased demands for flight simulation performance, personnel at NASA's Langley Research Center (LaRC), working with the contractor, developed extensions to a standard input/output system to provide for high bandwidth, low latency data acquisition and distribution. The Computer Automated Measurement and Control technology (IEEE standard 595) was extended to meet the performance requirements for real-time simulation. This technology extension increased the effective bandwidth by a factor of ten and increased the performance of modules necessary for simulator communications. This technology is being used by more than 80 leading technological developers in the United States, Canada, and Europe. Included among the commercial applications of this technology are nuclear process control, power grid analysis, process monitoring, real-time simulation, and radar data acquisition. Personnel at LaRC have completed the development of the use of supercomputers for simulation mathematical model computational to support real-time flight simulation. This includes the development of a real-time operating system and the development of specialized software and hardware for the CAMAC simulator network. This work, coupled with the use of an open systems software architecture, has advanced the state of the art in real time flight simulation. The data acquisition technology innovation and experience with recent developments in this technology are described.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, D.; Alekou, A.; Apollonio, M.

Here, the international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less thanmore » $$\\sim$$1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $$f_\\pi < 1.4\\%$$ at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.« less

Structural Bus and Release Mechanisms on the ST5 Satellites: Summary and Status

NASA Technical Reports Server (NTRS)

Rossoni, Peter

2007-01-01

The Space Technology 5 Mechanical System met the challenge of packaging a fully functional science and technology satellite system with its Deployer mechanism into a compact 0.07cu m volume. Three 25 kg satellites were orbited in constellation in March, 2006. The ST5 mechanical system is composed of 1) The Structural Bus; 2) Magnetometer Instrument Boom 3) Spacecraft Deployer Release Mechanism This system includes a highly integrated electronics enclosure as a multifunctional structure; a lightweight, magnetically clean Magnetometer Boom; the first use of Nitinol Shape-Memory Alloy trigger devices for deploying multiple spacecraft; an innovative compliant mount for the umbilical connector and a Deployer mechanism that imparts both separation velocity and mission spin rate to three constellation flying satellites These elements employed cutting-edge design and analysis tools, state-of-the-art testing facilities and proven engineering techniques to meet stringent performance criteria, enabling the mission s success.

NASA's Solar Dynamics Observatory (SDO): A Systems Approach to a Complex Mission

NASA Technical Reports Server (NTRS)

Ruffa, John A.; Ward, David K.; Bartusek, LIsa M.; Bay, Michael; Gonzales, Peter J.; Pesnell, William D.

2012-01-01

The Solar Dynamics Observatory (SDO) includes three advanced instruments, massive science data volume, stringent science data completeness requirements, and a custom ground station to meet mission demands. The strict instrument science requirements imposed a number of challenging drivers on the overall mission system design, leading the SDO team to adopt an integrated systems engineering presence across all aspects of the mission to ensure that mission science requirements would be met. Key strategies were devised to address these system level drivers and mitigate identified threats to mission success. The global systems engineering team approach ensured that key drivers and risk areas were rigorously addressed through all phases of the mission, leading to the successful SDO launch and on-orbit operation. Since launch, SDO's on-orbit performance has met all mission science requirements and enabled groundbreaking science observations, expanding our understanding of the Sun and its dynamic processes.

NASA's Solar Dynamics Observatory (SDO): A Systems Approach to a Complex Mission

NASA Technical Reports Server (NTRS)

Ruffa, John A.; Ward, David K.; Bartusek, Lisa M.; Bay, Michael; Gonzales, Peter J.; Pesnell, William D.

2012-01-01

The Solar Dynamics Observatory (SDO) includes three advanced instruments, massive science data volume, stringent science data completeness requirements, and a custom ground station to meet mission demands. The strict instrument science requirements imposed a number of challenging drivers on the overall mission system design, leading the SDO team to adopt an integrated systems engineering presence across all aspects of the mission to ensure that mission science requirements would be met. Key strategies were devised to address these system level drivers and mitigate identified threats to mission success. The global systems engineering team approach ensured that key drivers and risk areas were rigorously addressed through all phases of the mission, leading to the successful SDO launch and on-orbit operation. Since launch, SDO s on-orbit performance has met all mission science requirements and enabled groundbreaking science observations, expanding our understanding of the Sun and its dynamic processes.

A 0.18 μm CMOS LDO Regulator for an On-Chip Sensor Array Impedance Measurement System.

PubMed

Pérez-Bailón, Jorge; Márquez, Alejandro; Calvo, Belén; Medrano, Nicolás

2018-05-02

This paper presents a fully integrated 0.18 μm CMOS Low-Dropout (LDO) Voltage Regulator specifically designed to meet the stringent requirements of a battery-operated impedance spectrometry multichannel CMOS micro-instrument. The proposed LDO provides a regulated 1.8 V voltage from a 3.6 V to 1.94 V battery voltage over a −40 °C to 100 °C temperature range, with a compact topology (<0.10 mm² area) and a constant quiescent current of only 7.45 μA with 99.985% current efficiency, achieving remarkable state-of-art Figures of Merit (FoMs) for the regulating⁻transient performance. Experimental measurements validate its suitability for the target application, paving the way towards the future achievement of a truly portable System on Chip (SoC) platform for impedance sensors.

Lightweight ECC based RFID authentication integrated with an ID verifier transfer protocol.

PubMed

He, Debiao; Kumar, Neeraj; Chilamkurti, Naveen; Lee, Jong-Hyouk

2014-10-01

The radio frequency identification (RFID) technology has been widely adopted and being deployed as a dominant identification technology in a health care domain such as medical information authentication, patient tracking, blood transfusion medicine, etc. With more and more stringent security and privacy requirements to RFID based authentication schemes, elliptic curve cryptography (ECC) based RFID authentication schemes have been proposed to meet the requirements. However, many recently published ECC based RFID authentication schemes have serious security weaknesses. In this paper, we propose a new ECC based RFID authentication integrated with an ID verifier transfer protocol that overcomes the weaknesses of the existing schemes. A comprehensive security analysis has been conducted to show strong security properties that are provided from the proposed authentication scheme. Moreover, the performance of the proposed authentication scheme is analyzed in terms of computational cost, communicational cost, and storage requirement.

Pion contamination in the MICE muon beam

NASA Astrophysics Data System (ADS)

Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V. J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C. N.; Bowring, D.; Boyd, S.; Brashaw, T. W.; Bravar, U.; Bross, A. D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, C.; Chignoli, F.; Cline, D.; Cobb, J. H.; Colling, G.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L. M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Drews, M.; Drielsma, F.; Filthaut, F.; Fitzpatrick, T.; Franchini, P.; Francis, V.; Fry, L.; Gallagher, A.; Gamet, R.; Gardener, R.; Gourlay, S.; Grant, A.; Greis, J. R.; Griffiths, S.; Hanlet, P.; Hansen, O. M.; Hanson, G. G.; Hart, T. L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Hunt, C.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D. M.; Karadzhov, Y.; Kim, Y. K.; Kuno, Y.; Kyberd, P.; Lagrange, J.-B.; Langlands, J.; Lau, W.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Mazza, R.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J. J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J. C.; Oates, A.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M. A.; Ricciardi, S.; Roberts, T. J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, P.; Sakamato, H.; Sanders, D. A.; Santos, E.; Savidge, T.; Smith, P. J.; Snopok, P.; Soler, F. J. P.; Speirs, D.; Stanley, T.; Stokes, G.; Summers, D. J.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C. D.; Uchida, M. A.; Vankova-Kirilova, G.; Virostek, S.; Vretenar, M.; Warburton, P.; Watson, S.; White, C.; Whyte, C. G.; Wilson, A.; Winter, M.; Yang, X.; Young, A.; Zisman, M.

2016-03-01

The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240 MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than ~1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ < 1.4% at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

Pion contamination in the MICE muon beam

DOE PAGES

Adams, D.; Alekou, A.; Apollonio, M.; ...

2016-03-01

Here, the international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less thanmore » $$\\sim$$1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $$f_\\pi < 1.4\\%$$ at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.« less

Contamination control program results from three years of ground operations on the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Ray, David C.; Jelinsky, Sharon; Welsh, Barry Y.; Malina, Roger F.

1990-01-01

A stringent contamination-control plan has been developed for the optical components of the Extreme Ultraviolet Explorer instruments, whose performance in the 80-900 A wavelength range is highly sensitive to particulate and molecular contamination. The contamination-control program has been implemented over the last three years during assembly, test and calibration phases of the instrument. These phases have now been completed and the optics cavities of the instruments have been sealed until deployment in space. Various approaches are discussed which have been used during ground operations to meet optics' contamination goals within the project schedule and budget. The measured optical properties of EUV witness mirrors are also presented which remained with the flight mirrors during ground operations. These were used to track optical degradation due to contamination from the cleanroom and high-vacuum test-chamber environments.

A rigid and thermally stable all ceramic optical support bench assembly for the LSST Camera

NASA Astrophysics Data System (ADS)

Kroedel, Matthias; Langton, J. Brian; Wahl, Bill

2017-09-01

This paper will present the ceramic design, fabrication and metrology results and assembly plan of the LSST camera optical bench structure which is using the unique manufacturing features of the HB-Cesic technology. The optical bench assembly consists of a rigid "Grid" fabrication supporting individual raft plates mounting sensor assemblies by way of a rigid kinematic support system to meet extreme stringent requirements for focal plane planarity and stability.

Earth resources ground data handling systems for the 1980's

NASA Technical Reports Server (NTRS)

Vanvleck, E. M.; Sinclair, K. F.; Pitts, S. W.; Slye, R. E.

1973-01-01

The system requirements of an operational data handling system for earth resources in the decade of the 1980's are investigated. Attention is drawn to problems encountered in meeting the stringent agricultural user requirements of that time frame. Such an understanding of requirements is essential not only in designing the ground system that will ultimately handle the data, but also in design studies of the earth resources platform, sensors, and data relay satellites which may be needed.

The design, development and qualification of a lightweight antenna pointing mechanism

NASA Technical Reports Server (NTRS)

Shmulevitz, M.; Halsband, A.

1996-01-01

This paper describes the design, development, and qualification of a new lightweight and compact Antenna Pointing Mechanism (APM). The APM was specially designed to meet the stringent mass, envelope, and environmental requirements of OFFEQ experimental satellite. During the development phase, some problems were encountered with the brushless DC motors, slip ring contact resistance, and bearing drag torque. All of these problems were resolved, and two APM units have been operating successfully in orbit since April, 1995.

Meet the Editors: JGR-Atmospheres

NASA Astrophysics Data System (ADS)

Kumar, Mohi

2006-04-01

Three scientists were newly appointed and one scientist was reappointed last year as editors of JGR-Atmospheres. The three new editors, John Austin, Jose D. Fuentes, and Ruth Lieberman, along with returning editor Colin O'Dowd, would like to see several changes made to the journal. ``JGR-Atmospheres is still regarded as the highest-quality atmospheric science journal, having perhaps one of the most stringent and rigorous review processes,'' said O'Dowd. ``However, there is still room for improvement.''

Role of UASBs in River Water Quality Conservation in India

NASA Astrophysics Data System (ADS)

Gali, Veeresh; Thakur, Manisha; Gupta, Ashok Kumar; Ganguly, Rajiv

2018-03-01

Appropriate low-cost treatment technologies are a prerequisite for sound management of natural water resources against pollution in developing countries. Among the existing technologies available, UASB is found to be economically viable for India when considering all factors including operation and maintenance cost and treatment efficiency. However, this technology suffers setbacks in meeting the effluent guidelines prescribed by the government of India. Post treatment is supplemental to this process to meet the effluent standards in terms of removal of organic matter, suspended solids, pathogens and nutrients. Recent stringent effluent guidelines notified by the Ministry of Environment, Forests and Climate Change, Government of India has further reduced the limits of BOD by 3 times, COD and TSS by 5 times, NH4-N and total Nitrogen by 10 times as compared to the previous guidelines. Fecal Coliforms has been specified as <100MPN/100mL. In this paper, the present scenario of UASB based STPs and their role in river conservation is reviewed against the backdrop of stringent effluent guidelines. The minimum removal rates of BOD, COD and TSS in these plants are around 42 - 44% and the average removal rates are reported to be 66%, 61% and 65% respectively. The enhanced removal of BOD (97%), COD (98%) and TSS has been reported in STPs in conjunction with post treatment facilities such as facultative aerated lagoons, aeration tanks and polishing ponds.

Anogenital warts contain several distinct species of human papillomavirus.

PubMed Central

Krzyzek, R A; Watts, S L; Anderson, D L; Faras, A J; Pass, F

1980-01-01

Anogenital warts from 26 patients were examined for the presence of human papillomavirus (HPV). Although no whole, intact virus could be identified, varying amounts of nonintegrated HPV DNA were detected in 18 tissue specimens (70%) by employing both an agarose gel-ethidium bromide staining method and the Southern blot hybridization procedure. When hybridization analysis was performed under stringent conditions, six anogenital warts were observed to contain HPV genomic sequences related to either of the cutaneous viruses HPV type 1 (HPV-1) or HPV-2. In 12 tissue samples lacking sequence homology to either HPV-1 or HPV-2 under stringent conditions, HPV-related sequences were detected when the hybridization was performed under less stringent conditions, indicating that an HPV distinct from both HPV-1 and HPV-2 is also associated with these lesions. This anogenital HPV also appeared to be distinct from the other characterized types of HPV. These data indicate that at least three HPVs are associated with anogenital wart disease. Images PMID:6255208

Investigation of the Impact of Fuel Properties on Particulate Number Emission of a Modern Gasoline Direct Injection Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, Robert L; Fioroni, Gina; Fatouraie, Mohammad

Gasoline Direct Injection (GDI) has become the preferred technology for spark-ignition engines resulting in greater specific power output and lower fuel consumption, and consequently reduction in CO2 emission. However, GDI engines face a substantial challenge in meeting new and future emission limits, especially the stringent particle number (PN) emissions recently introduced in Europe and China. Studies have shown that the fuel used by a vehicle has a significant impact on engine out emissions. In this study, nine fuels with varying chemical composition and physical properties were tested on a modern turbo-charged side-mounted GDI engine with design changes to reduce particulatemore » emissions. The fuels tested included four fuels meeting US certification requirements; two fuels meeting European certification requirements; and one fuel meeting China 6 certification requirements being proposed at the time of this work. Two risk safeguard fuels (RSG), representing the properties of worst case market fuels in Europe and China, were also included. The particle number concentration of the solid particulates was measured in the engine-out exhaust flow at steady state engine operations with load and speed sweeps, and semi-transient load steps. The test results showed a factor of 6 PN emission difference among all certification fuels tested. Combined with detailed fuel analyses, this study evaluated important factors (such as oxygenates, carbon chain length and thermo-physical properties) that cause PN emissions which were not included in PMI index. A linear regression was performed to develop a PN predictive model which showed improved fitting quality than using PMI.« less

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

PubMed

Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

2017-01-01

The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

An Aircraft Separation Algorithm with Feedback and Perturbation

NASA Technical Reports Server (NTRS)

White, Allan L.

2010-01-01

A separation algorithm is a set of rules that tell aircraft how to maneuver in order to maintain a minimum distance between them. This paper investigates demonstrating that separation algorithms satisfy the FAA requirement for the occurrence of incidents by means of simulation. Any demonstration that a separation algorithm, or any other aspect of flight, satisfies the FAA requirement is a challenge because of the stringent nature of the requirement and the complexity of airspace operations. The paper begins with a probability and statistical analysis of both the FAA requirement and demonstrating meeting it by a Monte Carlo approach. It considers the geometry of maintaining separation when one plane must change its flight path. It then develops a simple feedback control law that guides the planes on their paths. The presence of feedback control permits the introduction of perturbations, and the stochastic nature of the chosen perturbation is examined. The simulation program is described. This paper is an early effort in the realistic demonstration of a stringent requirement. Much remains to be done.

Thermal design of the space shuttle external tank

NASA Technical Reports Server (NTRS)

Bachrtel, F. D.; Vaniman, J. L.; Stuckey, J. M.; Gray, C.; Widofsky, B.

1985-01-01

The shuttle external tank thermal design presents many challenges in meeting the stringent requirements established by the structures, main propulsion systems, and Orbiter elements. The selected thermal protection design had to meet these requirements, and ease of application, suitability for mass production considering low weight, cost, and high reliability. This development led to a spray-on-foam (SOFI) which covers the entire tank. The need and design for a SOFI material with a dual role of cryogenic insulation and ablator, and the development of the SOFI over SLA concept for high heating areas are discussed. Further issuses of minimum surface ice/frost, no debris, and the development of the TPS spray process considering the required quality and process control are examined.

Specifying to meet multiple demands.

PubMed

West, Martyn

2014-04-01

Choosing flooring for healthcare takes careful consideration. New legislation in healthcare places greater responsibility on those throughout the supply chain to ensure the safety of staff, visitors, and patients - now, and in the future. This undoubtedly impacts on flooring choices, but there is also the need for the most stringent hygiene, an aesthetically pleasing healing environment, maintenance and cleaning considerations, environmental impact, and some very specific requirements for dementia and elderly care to consider. Martyn West, Altro's specification manager, examines these key issues.

Latch fittings for the scientific instruments on the space telescope

NASA Technical Reports Server (NTRS)

Dozier, J. D.; Kaelber, E.

1983-01-01

Latch fittings which kinematically mount the replaceable scientific instruments onto the Space Telescope must maintain precise alignment and thermal stability for on-orbit observations. Design features which are needed to meet stringent criteria include the use of ceramic isolators for thermal and electrical insulation, materials with different coefficients of thermal expansion for athermalization, precision manufacturing procedures, and extremely tight tolerances. A specific latch fitting to be discussed is a ball-and-socket design. In addition, testing, crew aids, and problems will be covered.

Defense Infrastructure: Documentation Lacking to Fully Support How DOD Determined Specifications for the Landstuhl Replacement Medical Center

DTIC Science & Technology

2012-05-01

LEED system awards points for meeting a variety of standards and certifies buildings as silver, gold , or platinum. The replacement medical center’s...indicate that it may qualify for a “ gold ” certification once it has met the more stringent German design requirements. For example, the project will... Joanne Landesman assisted in the message and report development, Amie Steele assisted in developing the report’s tables and graphics, Jennifer Echard

17-4 PH and 15-5 PH

NASA Technical Reports Server (NTRS)

Johnson, Howard T.

1995-01-01

17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

Food and Drug Administration regulation and evaluation of vaccines.

PubMed

Marshall, Valerie; Baylor, Norman W

2011-05-01

The vaccine-approval process in the United States is regulated by the Center for Biologics Evaluation and Research of the US Food and Drug Administration. Throughout the life cycle of development, from preclinical studies to after licensure, vaccines are subject to rigorous testing and oversight. Manufacturers must adhere to good manufacturing practices and control procedures to ensure the quality of vaccines. As mandated by Title 21 of the Code of Regulations, licensed vaccines must meet stringent criteria for safety, efficacy, and potency.

Atmosphere Resource Recovery and Environmental Monitoring

NASA Technical Reports Server (NTRS)

Roman, Monsi; Howard, David

2015-01-01

Atmosphere Resource Recovery and Environmental Monitoring (ARREM) is a project focused on evolving existing and maturing emerging 'closed loop' atmosphere revitalization (AR) life support systems that produce clean, breathable air for crewmembers, and developing a suite of low mass, low power environmental monitors to detect and measure air- and waterborne constituents and contaminants. The objective is to improve reliability and efficiency, reduce mass and volume, and increase recovery of oxygen from carbon dioxide created by human metabolism from 43% to greater than 90%. The technology developments under ARREM are vital to extending human space missions from low-Earth orbit like the International Space Station to destinations deeper into space such as Mars where dependency on Earth for resupply of maintenance items and critical life support elements such as water and oxygen is not possible. The primary goal of the ARREM project is to demonstrate that systems meet the more stringent performance parameters for deep space exploration and are compatible with other systems within closed loop life support through a series of integrated tests performed in an environmental test chamber capable of simulating human metabolic activities and measuring systems outputs.

Development and manufacture of visor for helmet-mounted display

NASA Astrophysics Data System (ADS)

Krevor, David H.; McNelly, Gregg; Skubon, John; Speirs, Robert

2004-01-01

The manufacturing design and process development for the Visor for the JHMCS (Joint Helmet Mounted Cueing System) are discussed. The JHMCS system is a Helmet Mounted Display (HMD) system currently flying on the F-15, F-16 and F/A-18 aircraft. The Visor manufacturing processes are essential to both system performance and economy. The Visor functions both as the system optical combiner and personal protective equipment for the pilot. The Visor material is optical polycarbonate. For a military HMD system, the mechanical and environmental properties of the Visor are as necessary as the optical properties. The visor must meet stringent dimensional requirements to assure adequate system optical performance. Injection molding can provide dimensional fidelity to the requirements, if done properly. Concurrent design of the visor and the tool (i.e., the injection mold) is essential. The concurrent design necessarily considers manufacturing operations and the use environment of the Visor. Computer modeling of the molding process is a necessary input to the mold design. With proper attention to product design and tool development, it is possible to improve upon published standard dimensional tolerances for molded polycarbonate articles.

Technology Solutions Case Study: Evaluation of Ventilation Strategies in New Construction Multifamily Buildings, New York, New York

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2014-09-01

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the "normal leakage paths through the building envelope" disappear. Consortium for Advanced Residential Buildings researchers have found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust withmore » ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. This research effort included several weeks of building pressure monitoring to validate system performance of the different strategies for providing make-up air to apartments.« less

A compact, low-loss, tunable phase shifter on defect mitigated dielectrics up to 40 GHz

NASA Astrophysics Data System (ADS)

Orloff, Nathan; Long, Christian; Lu, Xifeng; Nair, Hari; Dawley, Natalie; Schlom, Darrell; Booth, James

With the emergence of the internet-of-things and increased connectivity of modern commerce, consumers have driven demand for wireless spectrum beyond current capacity and infrastructure capabilities. One way the telecommunications industry is addressing this problem is by pushing front-end electronics to higher frequencies, introducing carrier aggregation schemes, and developing spectrum-sharing techniques. Some of these solutions require frequency agile components that are vastly different from what is in today's marketplace. Perhaps the most basic and ubiquitous component in front-end electronics is the phase shifter. Phase shifters are particularly important for compact beam-forming antennas that may soon appear in commercial technology. Here, we demonstrate a compact, tunable phase shifter with very low insertion loss up to 40 GHz on a defect mitigated tunable dielectric. We demonstrate performance compared to barium-doped strontium titanate phase shifters. Such phase shifters could potentially meet the stringent size and performance characteristics demanded by telecommunications industry, readily facilitating massive multiple-input multiple-output antennas in the next-generation of mobile handsets.

Water impacts of CO2 emission performance standards for fossil fuel-fired power plants.

PubMed

Talati, Shuchi; Zhai, Haibo; Morgan, M Granger

2014-10-21

We employ an integrated systems modeling tool to assess the water impacts of the new source performance standards recently proposed by the U.S. Environmental Protection Agency for limiting CO2 emissions from coal- and gas-fired power plants. The implementation of amine-based carbon capture and storage (CCS) for 40% CO2 capture to meet the current proposal will increase plant water use by roughly 30% in supercritical pulverized coal-fired power plants. The specific amount of added water use varies with power plant and CCS designs. More stringent emission standards than the current proposal would require CO2 emission reductions for natural gas combined-cycle (NGCC) plants via CCS, which would also increase plant water use. When examined over a range of possible future emission standards from 1100 to 300 lb CO2/MWh gross, new baseload NGCC plants consume roughly 60-70% less water than coal-fired plants. A series of adaptation approaches to secure low-carbon energy production and improve the electric power industry's water management in the face of future policy constraints are discussed both quantitatively and qualitatively.

A Wirelessly Powered Micro-Spectrometer for Neural Probe-Pin Device

NASA Technical Reports Server (NTRS)

Choi, Sang H.; Kim, Min Hyuck; Song, Kyo D.; Yoon, Hargsoon; Lee, Uhn

2015-01-01

Treatment of neurological anomalies, places stringent demands on device functionality and size. A micro-spectrometer has been developed for use as an implantable neural probe to monitor neuro-chemistry in synapses. The microspectrometer, based on a NASA-invented miniature Fresnel grating, is capable of differentiating the emission spectra from various brain tissues. The micro-spectrometer meets the size requirements, and is able to probe the neuro-chemistry and suppression voltage typically associated with a neural anomaly. This neural probe-pin device (PPD) is equipped with wireless power technology (WPT) enabling operation in a continuous manner without requiring an implanted battery. The implanted neural PPD, together with a neural electronics interface and WPT, allow real-time measurement and control/feedback for remediation of neural anomalies. The design and performance of the combined PPD/WPT device for monitoring dopamine in a rat brain will be presented to demonstrate the current level of development. Future work on this device will involve the addition of an embedded expert system capable of performing semi-autonomous management of neural functions through a routine of sensing, processing, and control.

Extractive sampling and optical remote sensing of F100 aircraft engine emissions.

PubMed

Cowen, Kenneth; Goodwin, Bradley; Joseph, Darrell; Tefend, Matthew; Satola, Jan; Kagann, Robert; Hashmonay, Ram; Spicer, Chester; Holdren, Michael; Mayfield, Howard

2009-05-01

The Strategic Environmental Research and Development Program (SERDP) has initiated several programs to develop and evaluate techniques to characterize emissions from military aircraft to meet increasingly stringent regulatory requirements. This paper describes the results of a recent field study using extractive and optical remote sensing (ORS) techniques to measure emissions from six F-15 fighter aircraft. Testing was performed between November 14 and 16, 2006 on the trim-pad facility at Tyndall Air Force Base in Panama City, FL. Measurements were made on eight different F100 engines, and the engines were tested on-wing of in-use aircraft. A total of 39 test runs were performed at engine power levels that ranged from idle to military power. The approach adopted for these tests involved extractive sampling with collocated ORS measurements at a distance of approximately 20-25 nozzle diameters downstream of the engine exit plane. The emission indices calculated for carbon dioxide, carbon monoxide, nitric oxide, and several volatile organic compounds showed very good agreement when comparing the extractive and ORS sampling methods.

A wirelessly powered microspectrometer for neural probe-pin device

NASA Astrophysics Data System (ADS)

Choi, Sang H.; Kim, Min H.; Song, Kyo D.; Yoon, Hargsoon; Lee, Uhn

2015-12-01

Treatment of neurological anomalies, whether done invasively or not, places stringent demands on device functionality and size. We have developed a micro-spectrometer for use as an implantable neural probe to monitor neuro-chemistry in synapses. The micro-spectrometer, based on a NASA-invented miniature Fresnel grating, is capable of differentiating the emission spectra from various brain tissues. The micro-spectrometer meets the size requirements, and is able to probe the neuro-chemistry and suppression voltage typically associated with a neural anomaly. This neural probe-pin device (PPD) is equipped with wireless power technology (WPT) to enable operation in a continuous manner without requiring an implanted battery. The implanted neural PPD, together with a neural electronics interface and WPT, enable real-time measurement and control/feedback for remediation of neural anomalies. The design and performance of the combined PPD/WPT device for monitoring dopamine in a rat brain will be presented to demonstrate the current level of development. Future work on this device will involve the addition of an embedded expert system capable of performing semi-autonomous management of neural functions through a routine of sensing, processing, and control.

An economical route to high quality lubricants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andre, J.P.; Hahn, S.K.; Kwon, S.H.

1996-12-01

The current rends in the automotive and industrial markets toward more efficient engines, longer drain intervals, and lower emissions all contribute to placing increasingly stringent performance requirements on lubricants. The demand for higher quality synthetic and non-conventional basestocks is expected to grow at a much faster rate than that of conventional lube basestocks to meet these higher performance standards. Yukong Limited has developed a novel technology (the Yukong UCO Lube Process) for the economic production of high quality, high-viscosity-index lube basestocks from a fuels hydrocracker unconverted oil stream. A pilot plant based on this process has been producing oils formore » testing purposes since May 1994. A commercial facility designed to produce 3,500 BPD of VHVI lube basestocks cane on-stream at Yukong`s Ulsan refinery in October 1995. The Badger Technology Center of Raytheon Engineers and Constructors assisted Yukong during the development of the technology and prepared the basic process design package for the commercial facility. This paper presents process aspects of the technology and comparative data on investment and operating costs. Yukong lube basestock product properties and performance data are compared to basestocks produced by conventional means and by lube hydrocracking.« less

Simulation of the High Performance Time to Digital Converter for the ATLAS Muon Spectrometer trigger upgrade

NASA Astrophysics Data System (ADS)

Meng, X. T.; Levin, D. S.; Chapman, J. W.; Zhou, B.

2016-09-01

The ATLAS Muon Spectrometer endcap thin-Resistive Plate Chamber trigger project compliments the New Small Wheel endcap Phase-1 upgrade for higher luminosity LHC operation. These new trigger chambers, located in a high rate region of ATLAS, will improve overall trigger acceptance and reduce the fake muon trigger incidence. These chambers must generate a low level muon trigger to be delivered to a remote high level processor within a stringent latency requirement of 43 bunch crossings (1075 ns). To help meet this requirement the High Performance Time to Digital Converter (HPTDC), a multi-channel ASIC designed by CERN Microelectronics group, has been proposed for the digitization of the fast front end detector signals. This paper investigates the HPTDC performance in the context of the overall muon trigger latency, employing detailed behavioral Verilog simulations in which the latency in triggerless mode is measured for a range of configurations and under realistic hit rate conditions. The simulation results show that various HPTDC operational configurations, including leading edge and pair measurement modes can provide high efficiency (>98%) to capture and digitize hits within a time interval satisfying the Phase-1 latency tolerance.

Invited Article: Coherent imaging using seeded free-electron laser pulses with variable polarization: First results and research opportunities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capotondi, F.; Pedersoli, E.; Mahne, N.

2013-05-15

FERMI-Elettra, the first vacuum ultraviolet and soft X-ray free-electron laser (FEL) using by default a 'seeded' scheme, became operational in 2011 and has been opened to users since December 2012. The parameters of the seeded FERMI FEL pulses and, in particular, the superior control of emitted radiation in terms of spectral purity and stability meet the stringent requirements for single-shot and resonant coherent diffraction imaging (CDI) experiments. The advantages of the intense seeded FERMI pulses with variable polarization have been demonstrated with the first experiments performed using the multipurpose experimental station operated at the diffraction and projection imaging (DiProI) beamline.more » The results reported here were obtained with fixed non-periodic targets during the commissioning period in 2012 using 20-32 nm wavelength range. They demonstrate that the performance of the FERMI FEL source and the experimental station meets the requirements of CDI, holography, and resonant magnetic scattering in both multi- and single-shot modes. Moreover, we present the first magnetic scattering experiments employing the fully circularly polarized FERMI pulses. The ongoing developments aim at pushing the lateral resolution by using shorter wavelengths provided by double-stage cascaded FERMI FEL-2 and probing ultrafast dynamic processes using different pump-probe schemes, including jitter-free seed laser pump or FEL-pump/FEL-probe with two color FEL pulses generated by the same electron bunch.« less

Non-Intrusive Laser-Induced Imaging for Speciation and Patternation in High Pressure Gas Turbine Combustors

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Zaller, Michelle M.; Hicks, Yolanda R.; Anderson, Robert C.

1999-01-01

The next generation of was turbine combustors for aerospace applications will be required to meet increasingly stringent constraints on fuel efficiency, noise abatement, and emissions. The power plants being designed to meet these constraints will operate at extreme conditions of temperature and pressure, thereby generating unique challenges to the previously employed diagnostic methodologies. Current efforts at NASA Glenn Research Center (GRC) utilize optically accessible, high pressure flametubes and sector combustor rigs to probe, via advanced nonintrusive laser techniques, the complex flowfields encountered in advanced combustor designs. The fuel-air mixing process is of particular concern for lowering NO(x) emissions generated in lean, premixed engine concepts. Using planar laser-induced fluorescence (PLIF) we have obtained real-time, detailed imaging of the fuel spray distribution for a number of fuel injector over a wide range of operational conditions that closely match those expected in the proposed propulsion systems. Using a novel combination of planar imaging, of fuel fluorescence and computational analysis that allows an examination of the flowfield from any perspective, we have produced spatially and temporally resolved fuel-air distribution maps. These maps provide detailed insight into the fuel injection at actual conditions never before possible, thereby greatly enhancing the evaluation of fuel injector performance and combustion phenomena.

3D Interconnected Carbon Fiber Network-Enabled Ultralong Life Na3 V2 (PO4 )3 @Carbon Paper Cathode for Sodium-Ion Batteries.

PubMed

Kretschmer, Katja; Sun, Bing; Zhang, Jinqiang; Xie, Xiuqiang; Liu, Hao; Wang, Guoxiu

2017-03-01

Sodium-ion batteries (NIBs) are an emerging technology, which can meet increasing demands for large-scale energy storage. One of the most promising cathode material candidates for sodium-ion batteries is Na 3 V 2 (PO 4 ) 3 due to its high capacity, thermal stability, and sodium (Na) Superionic Conductor 3D (NASICON)-type framework. In this work, the authors have significantly improved electrochemical performance and cycling stability of Na 3 V 2 (PO 4 ) 3 by introducing a 3D interconnected conductive network in the form of carbon fiber derived from ordinary paper towel. The free-standing Na 3 V 2 (PO 4 ) 3 -carbon paper (Na 3 V 2 (PO 4 ) 3 @CP) hybrid electrodes do not require a metallic current collector, polymeric binder, or conducting additives to function as a cathode material in an NIB system. The Na 3 V 2 (PO 4 ) 3 @CP cathode demonstrates extraordinary long term cycling stability for 30 000 deep charge-discharge cycles at a current density of 2.5 mA cm -2 . Such outstanding cycling stability can meet the stringent requirements for renewable energy storage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nonintrusive laser-induced imaging for speciation and patternation in high-pressure gas turbine combustors

NASA Astrophysics Data System (ADS)

Locke, Randy J.; Zaller, Michelle M.; Hicks, Yolanda R.; Anderson, Robert C.

1999-10-01

The next generation of ga turbine combustors for aerospace applications will be required to meet increasingly stringent constraints on fuel efficiency, noise abatement, and emissions. The power plants being designed to meet these constraints will operate at extreme conditions of temperature and pressure, thereby generating unique challenges to the previously employed diagnostic methodologies. Current efforts at NASA Glenn Research Center GRC utilize optically accessible, high-pressure flametubes and sector combustor rigs to probe, via advanced nonintrusive laser techniques, the complex flowfields encountered in advanced combustor designs. The fuel-air mixing process is of particular concern for lowering NOx emissions generated in lean, premixed engine concepts. Using planar laser-induced fluorescence we have obtained real- time, detailed imaging of the fuel spray distribution for a number of fuel injectors over a wide range of operational conditions that closely match those expected in the proposed propulsion systems. Using a novel combination of planar imaging of fuel fluorescence and computational analysis that allows an examination of the flowfield from any perspective, we have produced spatially and temporally resolved fuel-air distribution maps. These maps provide detailed insight into the fuel injection process at actual conditions never before possible, thereby greatly enhancing the evaluation of fuel injector performance and combustion phenomena.

New levothyroxine formulation meeting 95-105% specification over the whole shelf-life: results from two pharmacokinetic trials.

PubMed

Gottwald-Hostalek, Ulrike; Uhl, Wolfgang; Wolna, Peter; Kahaly, George J

2017-02-01

Small levothyroxine (L-T4) dose changes can lead to significant clinical effects. To ensure thyroid hormone levels are safely maintained, authorities are increasingly adopting stricter potency specifications for L-T4, the most stringent of these being 95-105% of the labeled dose over the whole shelf-life. Levothyroxine sodium (Euthyrox, Eutirox, Lévothyrox ) has been reformulated, and two studies performed, to ensure bioequivalence to the currently marketed formulation and dosage form proportionality of the new formulation. The bioequivalence study was an open-label, randomized, single-dose, two-period, two-sequence crossover comparing the highest dosage strengths of the currently marketed and the new L-T4 formulation at a total dose of 600 μg. The dosage form proportionality study was an open-label, randomized, three-period, six-sequence crossover, comparing 50 μg, 100 μg, and 200 μg L-T4 tablets, at a total dose of 600 μg. Blood samples were taken at predefined time intervals. Primary outcomes were area under the curve (AUC) and maximum concentration (C max ) of thyroxine (T4) in plasma. In the bioequivalence study, comparing the T4 profiles for the new and current formulation of L-T4, the geometric least square mean ratio of the baseline-adjusted AUC 0-72,adj was 99.3% (90% confidence interval [CI]: 95.6-103.2) and the C max,adj was 101.7% (90% CI: 98.8-104.6). Bioequivalence was established if the 90% CI lay within the predefined 0.9-1.11 limits. In the dosage form proportionality study, pairwise comparisons ranged from 99.3% to 104.8%, and all 95% CIs were within the predefined CI range (0.8-1.25): the three dose strengths were dosage form proportional. The new formulation of L-T4 meets the most stringent potency specification guidelines, and has been demonstrated to be bioequivalent to the current formulation and to show dosage form proportionality. The new formulation will enable patients to receive a dose fine tuned to their medical needs, contributing to improved safety in the use of L-T4.

RS-84 Engine Completes Design Review

NASA Technical Reports Server (NTRS)

2003-01-01

This is an artist's concept of the kerosene-fueled RS-84 engine, one of several technologies competing to power NASA's next generation of launch vehicles. The RS-84 has successfully completed its preliminary design review as a reusable, liquid kerosene booster engine that will deliver a thrust level of 1 million pounds of force. The preliminary design review is a lengthy technical analysis that evaluates engine design according to stringent system requirements. The review ensures development is on target to meet Next Generation Launch Technology goals: Improved safety, reliability, and cost.

Application of technology developed for flight simulation at NASA. Langley Research Center

NASA Technical Reports Server (NTRS)

Cleveland, Jeff I., II

1991-01-01

In order to meet the stringent time-critical requirements for real-time man-in-the-loop flight simulation, computer processing operations including mathematical model computation and data input/output to the simulators must be deterministic and be completed in as short a time as possible. Personnel at NASA's Langley Research Center are currently developing the use of supercomputers for simulation mathematical model computation for real-time simulation. This, coupled with the use of an open systems software architecture, will advance the state-of-the-art in real-time flight simulation.

Materials technology assessment for a 1050 K Stirling space engine design

NASA Technical Reports Server (NTRS)

Scheuermann, Coulson M.; Dreshfield, Robert L.; Gaydosh, Darrell J.; Kiser, James D.; Mackay, Rebecca A.; Mcdaniels, David L.; Petrasek, Donald W.; Vannucci, Raymond D.; Bowles, Kenneth J.; Watson, Gordon K.

1988-01-01

An assessment of materials technology and proposed materials selection was made for the 1050 K (superalloy) Stirling Space Engine design. The objectives of this assessment were to evaluate previously proposed materials selections, evaluate the current state-of-the-art materials, propose potential alternate materials selections and identify research and development efforts needed to provide materials that can meet the stringent system requirements. This assessment generally reaffirmed the choices made by the contractor. However, in many cases alternative choices were described and suggestions for needed materials and fabrication research and development were made.

Particulate matter emissions from combustion of wood in district heating applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghafghazi, S.; Sowlati, T.; Sokhansanj, Shahabaddine

2011-01-01

The utilization of wood biomass to generate district heat and power in communities that have access to this energy source is increasing. In this paper the effect of wood fuel properties, combustion condition, and flue gas cleaning system on variation in the amount and formation of particles in the flue gas of typical district heating wood boilers are discussed based on the literature survey. Direct measurements of particulate matter (PM) emissions from wood boilers with district heating applications are reviewed and presented. Finally, recommendations are given regarding the selection of wood fuel, combustion system condition, and flue gas cleaning systemmore » in district heating systems in order to meet stringent air quality standards. It is concluded that utilization of high quality wood fuel, such as wood pellets produced from natural, uncontaminated stem wood, would generate the least PM emissions compared to other wood fuel types. Particulate matter emissions from grate burners equipped with electrostatic precipitators when using wood pellets can be well below stringent regulatory emission limit such as particulate emission limit of Metro Vancouver, Canada.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenblatt, Jeffery B.

A California Greenhouse Gas Inventory Spreadsheet (GHGIS) model was developed to explore the impact of combinations of state policies on state greenhouse gas (GHG) and regional criteria pollutant emissions. The model included representations of all GHG- emitting sectors of the California economy (including those outside the energy sector, such as high global warming potential gases, waste treatment, agriculture and forestry) in varying degrees of detail, and was carefully calibrated using available data and projections from multiple state agencies and other sources. Starting from basic drivers such as population, numbers of households, gross state product, numbers of vehicles, etc., the modelmore » calculated energy demands by type (various types of liquid and gaseous hydrocarbon fuels, electricity and hydrogen), and finally calculated emissions of GHGs and three criteria pollutants: reactive organic gases (ROG), nitrogen oxides (NOx), and fine (2.5 ?m) particulate matter (PM2.5). Calculations were generally statewide, but in some sectors, criteria pollutants were also calculated for two regional air basins: the South Coast Air Basin (SCAB) and the San Joaquin Valley (SJV). Three scenarios were developed that attempt to model: (1) all committed policies, (2) additional, uncommitted policy targets and (3) potential technology and market futures. Each scenario received extensive input from state energy planning agencies, in particular the California Air Resources Board. Results indicate that all three scenarios are able to meet the 2020 statewide GHG targets, and by 2030, statewide GHG emissions range from between 208 and 396 MtCO2/yr. However, none of the scenarios are able to meet the 2050 GHG target of 85 MtCO2/yr, with emissions ranging from 188 to 444 MtCO2/yr, so additional policies will need to be developed for California to meet this stringent future target. A full sensitivity study of major scenario assumptions was also performed. In terms of criteria pollutants, targets were less well-defined, but while all three scenarios were able to make significant reductions in ROG, NOx and PM2.5 both statewide and in the two regional air basins, they may nonetheless fall short of what will be required by future federal standards. Specifically, in Scenario 1, regional NOx emissions are approximately three times the estimated targets for both 2023 and 2032, and in Scenarios 2 and 3, NOx emissions are approximately twice the estimated targets. Further work is required in this area, including detailed regional air quality modeling, in order to determine likely pathways for attaining these stringent targets.« less

Design, analysis, and testing of high frequency passively damped struts

NASA Technical Reports Server (NTRS)

Yiu, Y. C.; Davis, L. Porter; Napolitano, Kevin; Ninneman, R. Rory

1993-01-01

Objectives of the research are: (1) to develop design requirements for damped struts to stabilize control system in the high frequency cross-over and spill-over range; (2) to design, fabricate and test viscously damped strut and viscoelastically damped strut; (3) to verify accuracy of design and analysis methodology of damped struts; and (4) to design and build test apparatus, and develop data reduction algorithm to measure strut complex stiffness. In order to meet the stringent performance requirements of the SPICE experiment, the active control system is used to suppress the dynamic responses of the low order structural modes. However, the control system also inadvertently drives some of the higher order modes unstable in the cross-over and spill-over frequency range. Passive damping is a reliable and effective way to provide damping to stabilize the control system. It also improves the robustness of the control system. Damping is designed into the SPICE testbed as an integral part of the control-structure technology.

SeaWiFS technical report series. Volume 11: Analysis of selected orbit propagation models for the SeaWiFS mission

NASA Technical Reports Server (NTRS)

Patt, Frederick S.; Hoisington, Charles M.; Gregg, Watson W.; Coronado, Patrick L.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Indest, A. W. (Editor)

1993-01-01

An analysis of orbit propagation models was performed by the Mission Operations element of the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) Project, which has overall responsibility for the instrument scheduling. The orbit propagators selected for this analysis are widely available general perturbations models. The analysis includes both absolute accuracy determination and comparisons of different versions of the models. The results show that all of the models tested meet accuracy requirements for scheduling and data acquisition purposes. For internal Project use the SGP4 propagator, developed by the North American Air Defense (NORAD) Command, has been selected. This model includes atmospheric drag effects and, therefore, provides better accuracy. For High Resolution Picture Transmission (HRPT) ground stations, which have less stringent accuracy requirements, the publicly available Brouwer-Lyddane models are recommended. The SeaWiFS Project will make available portable source code for a version of this model developed by the Data Capture Facility (DCF).

Radiation-hardened microwave communications system

NASA Astrophysics Data System (ADS)

Smith, S. F.; Bible, D. W.; Crutcher, R. I.; Hannah, J. H.; Moore, J. A.; Nowlin, C. H.; Vandermolen, R. I.; Chagnot, D.; Leroy, A.

1993-03-01

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10(exp 7) rads and at elevated ambient temperatures.

Structural Feasibility Analysis of a Robotically Assembled Very Large Aperture Optical Space Telescope

NASA Technical Reports Server (NTRS)

Wilkie, William Keats; Williams, R. Brett; Agnes, Gregory S.; Wilcox, Brian H.

2007-01-01

This paper presents a feasibility study of robotically constructing a very large aperture optical space telescope on-orbit. Since the largest engineering challenges are likely to reside in the design and assembly of the 150-m diameter primary reflector, this preliminary study focuses on this component. The same technology developed for construction of the primary would then be readily used for the smaller optical structures (secondary, tertiary, etc.). A reasonable set of ground and on-orbit loading scenarios are compiled from the literature and used to define the structural performance requirements and size the primary reflector. A surface precision analysis shows that active adjustment of the primary structure is required in order to meet stringent optical surface requirements. Two potential actuation strategies are discussed along with potential actuation devices at the current state of the art. The finding of this research effort indicate that successful technology development combined with further analysis will likely enable such a telescope to be built in the future.

Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO

NASA Astrophysics Data System (ADS)

Yver Kwok, C.; Laurent, O.; Guemri, A.; Philippon, C.; Wastine, B.; Rella, C. W.; Vuillemin, C.; Truong, F.; Delmotte, M.; Kazan, V.; Darding, M.; Lebègue, B.; Kaiser, C.; Xueref-Rémy, I.; Ramonet, M.

2015-09-01

To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about 10 years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field.

Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO

NASA Astrophysics Data System (ADS)

Yver Kwok, C.; Laurent, O.; Guemri, A.; Philippon, C.; Wastine, B.; Rella, C. W.; Vuillemin, C.; Truong, F.; Delmotte, M.; Kazan, V.; Darding, M.; Lebègue, B.; Kaiser, C.; Ramonet, M.

2015-04-01

To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about ten years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field.

Jitter Test Program and On-Orbit Mitigation Strategies for Solar Dynamic Observatory

NASA Technical Reports Server (NTRS)

Liu, Kuo-Chia; Kenney, Thomas; Maghami, Peiman; Mule, Pete; Blaurock, Carl; Haile, William B.

2007-01-01

The Solar Dynamic Observatory (SDO) aims to study the Sun's influence on the Earth, the source, storage, and release of the solar energy, and the interior structure of the Sun. During science observations, the jitter stability at the instrument focal plane must be maintained to less than a fraction of an arcsecond for two of the SDO instruments. To meet these stringent requirements, a significant amount of analysis and test effort has been devoted to predicting the jitter induced from various disturbance sources. This paper presents an overview of the SDO jitter analysis approach and test effort performed to date. It emphasizes the disturbance modeling, verification, calibration, and validation of the high gain antenna stepping mechanism and the reaction wheels, which are the two largest jitter contributors. This paper also describes on-orbit mitigation strategies to protect the system from analysis model uncertainties. Lessons learned from the SDO jitter analyses and test programs are included in the paper to share the knowledge gained with the community.

High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.

2007-01-01

Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.

High-speed noise-free optical quantum memory

NASA Astrophysics Data System (ADS)

Kaczmarek, K. T.; Ledingham, P. M.; Brecht, B.; Thomas, S. E.; Thekkadath, G. S.; Lazo-Arjona, O.; Munns, J. H. D.; Poem, E.; Feizpour, A.; Saunders, D. J.; Nunn, J.; Walmsley, I. A.

2018-04-01

Optical quantum memories are devices that store and recall quantum light and are vital to the realization of future photonic quantum networks. To date, much effort has been put into improving storage times and efficiencies of such devices to enable long-distance communications. However, less attention has been devoted to building quantum memories which add zero noise to the output. Even small additional noise can render the memory classical by destroying the fragile quantum signatures of the stored light. Therefore, noise performance is a critical parameter for all quantum memories. Here we introduce an intrinsically noise-free quantum memory protocol based on two-photon off-resonant cascaded absorption (ORCA). We demonstrate successful storage of GHz-bandwidth heralded single photons in a warm atomic vapor with no added noise, confirmed by the unaltered photon-number statistics upon recall. Our ORCA memory meets the stringent noise requirements for quantum memories while combining high-speed and room-temperature operation with technical simplicity, and therefore is immediately applicable to low-latency quantum networks.

Evaluation of Chemical Coating Processes for AXAF

NASA Technical Reports Server (NTRS)

Engelhaupt, Darell; Ramsey, Brian; Mendrek, Mitchell

1998-01-01

The need existed at MSFC for the development and fabrication of radioisotope calibration sources of cadmium 109 and iron 55 isotopes. This was in urgent response to the AXA-F program. Several issues persisted in creating manufacturing difficulties for the supplier. In order to meet the MSFC requirements very stringent control needed to be maintained for the coating quality, specific activity and thickness. Due to the difficulties in providing the precisely controlled devices for testing, the delivery of the sources was seriously delayed. It became imperative that these fabrication issues be resolved to avoid further delays in this AXA-F observatory key component. The objectives are: 1) Research and provide expert advice on coating materials and procedures. 2) Research and recommend solutions to problems that have been experienced with the coating process. 3) Provide recommendations on the selection and preparation of substrates. 4) Provide consultation on the actual coating process including the results of the qualification and acceptance test programs. 5) Perform independent tests at UAH or MSFC as necessary.

30 CFR 810.4 - Responsibility.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR PERMANENT PROGRAM...) The Director shall ensure that performance standards and design requirements at least as stringent as... State regulatory authority shall ensure that performance standards and design requirements at least as...

Multichip module technology for automotive application

NASA Astrophysics Data System (ADS)

Johnson, R. Wayne; Evans, John L.; Bosley, Larry

1995-01-01

Advancements in multichip module technology are creating design freedoms previously unavailable to design engineers. These advancements are opening new markets for laminate based multichip module products. In particular, material improvements in laminate printed wiring boards are allowing multichip module technology to meet more stringent environmental conditions. In addition, improvements in encapsulants and adhesives are enhancing the capabilities of multichip module technology to meet harsh environment. Furthermore, improvements in manufacturing techniques are providing the reliability improvements necessary for use in high quality electronic systems. These advances are making multichip module technology viable for high volume, harsh environment applications like under-the-hood automotive electronics. This paper will provide a brief review of multichip module technology, a discussion of specific research activities with Chrysler for use of multichip modules in automotive engine controllers and finally a discussion of prototype multichip modules fabricated and tested.

Robust Multilayer Insulation for Cryogenic Systems

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Scholtens, B. F.; Augustynowicz, S. D.

2007-01-01

New requirements for thermal insulation include robust Multilayer insulation (MU) systems that work for a range of environments from high vacuum to no vacuum. Improved MLI systems must be simple to install and maintain while meeting the life-cycle cost and thermal performance objectives. Performance of actual MLI systems has been previously shown to be much worse than ideal MLI. Spacecraft that must contain cryogens for both lunar service (high vacuum) and ground launch operations (no vacuum) are planned. Future cryogenic spacecraft for the soft vacuum environment of Mars are also envisioned. Industry products using robust MLI can benefit from improved cost-efficiency and system safety. Novel materials have been developed to operate as excellent thermal insulators at vacuum levels that are much less stringent than the absolute high vacuum requirement of current MLI systems. One such robust system, Layered Composite Insulation (LCI), has been developed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. The experimental testing and development of LCI is the focus of this paper. LCI thermal performance under cryogenic conditions is shown to be six times better than MLI at soft vacuum and similar to MLI at high vacuum. The experimental apparent thermal conductivity (k-value) and heat flux data for LCI systems are compared with other MLI systems.

Assessment of wastewater treatment facility compliance with decreasing ammonia discharge limits using a regression tree model.

PubMed

Suchetana, Bihu; Rajagopalan, Balaji; Silverstein, JoAnn

2017-11-15

A regression tree-based diagnostic approach is developed to evaluate factors affecting US wastewater treatment plant compliance with ammonia discharge permit limits using Discharge Monthly Report (DMR) data from a sample of 106 municipal treatment plants for the period of 2004-2008. Predictor variables used to fit the regression tree are selected using random forests, and consist of the previous month's effluent ammonia, influent flow rates and plant capacity utilization. The tree models are first used to evaluate compliance with existing ammonia discharge standards at each facility and then applied assuming more stringent discharge limits, under consideration in many states. The model predicts that the ability to meet both current and future limits depends primarily on the previous month's treatment performance. With more stringent discharge limits predicted ammonia concentration relative to the discharge limit, increases. In-sample validation shows that the regression trees can provide a median classification accuracy of >70%. The regression tree model is validated using ammonia discharge data from an operating wastewater treatment plant and is able to accurately predict the observed ammonia discharge category approximately 80% of the time, indicating that the regression tree model can be applied to predict compliance for individual treatment plants providing practical guidance for utilities and regulators with an interest in controlling ammonia discharges. The proposed methodology is also used to demonstrate how to delineate reliable sources of demand and supply in a point source-to-point source nutrient credit trading scheme, as well as how planners and decision makers can set reasonable discharge limits in future. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic fields and the technology challenges they pose to beam-based equipment: a semiconductor perspective

NASA Astrophysics Data System (ADS)

Esqueda, Vincent; Montoya, Julian A.

2005-08-01

As semiconductor devices shrink in size to accommodate faster processing speeds, the need for higher resolution beam-based metrology equipment and beam-based writing equipment will increase. The electron and ion beams used within these types of equipment are sensitive to very small variations in magnetic force applied to the beam. This phenomenon results from changes in Alternating Current (AC) and Direct Current (DC) magnetic flux density at the beam column which causes deflections of the beam that can impact equipment performance. Currently the most sensitive beam-based microscope manufacturers require an ambient magnetic field environment that does not have variations that exceed 0.2 milli-Gauss (mG). Studies have shown that such low levels of magnetic flux density can be extremely difficult to achieve. As examples, scissor lifts, vehicles, metal chairs, and doors moving in time and space under typical use conditions can create distortions in the Earth's magnetic field that can exceed 0.2 mG at the beam column. In addition it is known that changes in the Earth's magnetic field caused by solar flares, earthquakes, and variations in the Earth's core itself all cause changes in the magnetic field that can exceed 0.2 mG. This paper will provide the reader with the basic understanding of the emerging problem, will discuss the environmental and facility level challenges associated in meeting such stringent magnetic field environments, will discuss some of the mitigation techniques used to address the problem, and will close by discussing needs for further research in this area to assure semiconductor and nanotechnology industries are pre-positioned for even more stringent magnetic field environmental requirements.

ICESat-2 ATLAS Beam Steering Mechanism (BSM)

NASA Technical Reports Server (NTRS)

Hinkle, Matthew

2015-01-01

This work covers the design and test of a beam steering mechanism (BSM) used to accurately guide a laser on the Advanced Topographic Laser Altimeter System (ATLAS) down to Earth in order to measure elevation. It describes the main components in the BSM that allows it to perform and meet stringent requirements. Requirements of the BSM include two-axis steering of the transmitted laser beam, +-5000 uRad mechanical motion in each axis, and 1.5 uRad RMS pointing stability among many other requirements. The BSM uses four voice coil actuators in order to locate the mirror at the angle we need. There are four Differential Position Sensors that determine the position and angle of the mirror at all times. These sensors were verified through optical testing in both ambient and thermal conditions. Testing and extensive analyses were performed on the two-axis flexure throughout the program to check flexure thickness, positive margins, and infinite life. The mirror mount design has been modified to eliminate radial preload, while incorporating a titanium wave spring to provide an axial preload of 10.8N. The BSM underwent multiple tests in order to verify all components work as required under various conditions.

Analytical Kinematics and Coupled Vibrations Analysis of Mechanical System Operated by Solar Array Drive Assembly

NASA Astrophysics Data System (ADS)

Sattar, M.; Wei, C.; Jalali, A.; Sattar, R.

2017-07-01

To address the impact of solar array (SA) anomalies and vibrations on performance of precision space-based operations, it is important to complete its accurate jitter analysis. This work provides mathematical modelling scheme to approximate kinematics and coupled micro disturbance dynamics of rigid load supported and operated by solar array drive assembly (SADA). SADA employed in analysis provides a step wave excitation torque to activate the system. Analytical investigations into kinematics is accomplished by using generalized linear and Euler angle coordinates, applying multi-body dynamics concepts and transformations principles. Theoretical model is extended, to develop equations of motion (EoM), through energy method (Lagrange equation). The main emphasis is to research coupled frequency response by determining energies dissipated and observing dynamic behaviour of internal vibratory systems of SADA. The disturbance model captures discrete active harmonics of SADA, natural modes and vibration amplifications caused by interactions between active harmonics and structural modes of mechanical assembly. The proposed methodology can help to predict true micro disturbance nature of SADA operating rigid load. Moreover, performance outputs may be compared against actual mission requirements to assess precise spacecraft controller design to meet next space generation stringent accuracy goals.

Advanced Envelope Research for Factory Built Housing, Phase 3. Design Development and Prototyping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levy, E.; Kessler, B.; Mullens, M.

2014-01-01

The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet themore » thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research -- stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.« less

Advanced Envelope Research for Factory Built Housing, Phase 3 -- Design Development and Prototyping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levy, E.; Kessler, B.; Mullens, M.

2014-01-01

The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet themore » thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research -- stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.« less

Stud Walls With Continuous Exterior Insulation for Factory Built Housing: New York, New York (Fact Sheet), NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet themore » thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research - stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.« less

Technology Solutions Case Study: Stud Walls with Continuous Exterior Insulation for Factory Built Housing

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

The Advanced Envelope Research effort will provide factory homebuilders with high performance, cost-effective alternative envelope designs. In the near term, these technologies will play a central role in meeting stringent energy code requirements. For manufactured homes, the thermal requirements, last updated by statute in 1994, will move up to the more rigorous IECC 2012 levels in 2013, the requirements of which are consistent with site built and modular housing. This places added urgency on identifying envelope technologies that the industry can implement in the short timeframe. The primary goal of this research is to develop wall designs that meet themore » thermal requirements based on 2012 IECC standards. Given the affordable nature of manufactured homes, impact on first cost is a major consideration in developing the new envelope technologies. This work is part of a four-phase, multi-year effort. Phase 1 identified seven envelope technologies and provided a preliminary assessment of three selected methods for building high performance wall systems. Phase 2 focused on the development of viable product designs, manufacturing strategies, addressing code and structural issues, and cost analysis of the three selected options. An industry advisory committee helped critique and select the most viable solution to move further in the research — stud walls with continuous exterior insulation. Phase 3, the subject of the current report, focused on the design development of the selected wall concept and explored variations on the use of exterior foam insulation. The scope also included material selection, manufacturing and cost analysis, and prototyping and testing.« less

High precision moving magnet chopper for variable operation conditions

NASA Technical Reports Server (NTRS)

Aicher, Winfried; Schmid, Manfred

1994-01-01

In the context of an ESTEC technology contract, a Chopping Mechanism was developed and built with the Far Infrared and Submillimeter Telescope (FIRST) astronomy mission as a reference. The task of the mechanism is to tilt the subreflector of the telescope with an assumed mass of 2.5 kg about one chopping axis at nominal frequencies of up to 5 Hz and chopping angles of up to +/- 11.25 mrad with high efficiency (minimum time for position change). The chopping axis is required to run through the subreflector vertex. After performing a concept trade-off also considering the low operational temperatures in the 130 K range, a design using moving magnet actuators was found to be the favorite one. In addition, a bearing concept using flexible pivots was chosen to meet the high chopping accuracy required. With this approach, a very reliable design could be realized, since the actuators work without any mechanical contact between its moving and fixed parts, and the only bearings used are two flexible pivots supporting the subreflector mounting interface. The mechanism was completely built in titanium in a lightweight and stiff design. The moving magnet actuators were designed to meet the stringent requirements for minimum risetime (time necessary to move from one angular position to a new one) in the 20 msec range. The angular position and the corresponding chopping frequency as well can be arbitrarily selected by the user.

A magnetic isolation and pointing system for the astrometric telescope facility

NASA Technical Reports Server (NTRS)

Smith, Marcie; Hibble, William; Wolke, Patrick J.

1993-01-01

The astrometric telescope facility (ATF), a 20-meter telescope designed for long-term detection and observation of planetary systems outside of the solar system, is scheduled to be a major user of the Space Station's payload pointing system (PPS) capabilities. However, because the ATF has such a stringent pointing stability specification (as low as 0.01 arcsec error over the frequency range from 5 to 200 hertz) and requires +/- 180-degree roll rotation around the telescope's line of sight, the ATF's utilization of the PPS requires the addition of a mechanism or mechanisms to enhance the basic PPS capabilities. The results of a study conducted to investigate the ATF pointing performance achievable by the addition of a magnetic isolation and pointing (MIPS) system between the PPS upper gimbal and the ATF, and separately, by the addition of a passive isolation system between the Space Station and the PPS base are presented. In addition, the study produced requirements on magnetic force and gap motion as a function of the level of Space Station disturbance. These results were used to support the definition of a candidate MIPS. Pointing performance results from the study indicate that a MIPS can meet the ATF pointing requirements in the presence of a PPS base transitional acceleration of up to 0.018g, with reasonable restrictions placed on the isolation and pointing bandwidths. By contrast, the passive base isolator system must have an unrealistically low isolation bandwidth on all axes (less than 0.1 hertz) to meet ATF pointing requirements. The candidate MIPS is based on an assumed base translational disturbance of 0.01g. The system fits within the available annular region between the PPS and ATF while meeting power and weight limitations and providing the required payload roll motion. Payload data and power services are provided by noncontacting transfer devices.

The Installation of a P.E.T. Pharmacy at Washington University

NASA Astrophysics Data System (ADS)

Gaehle, G.; Schwarz, S.; Mueller, M.; Margenau, B.; Welch, M. J.

2003-08-01

Washington University has produced radioisotopes for medical application since the early 1960s. In order to serve seven PET scanners and to meet more stringent government regulations we have installed a new PET pharmacy based on our past years of experiences. The new pharmacy was installed at the site of the 3.7 MeV tandem cascade accelerator that was decommissioned in April of 2001. The pharmacy consists of a production lab, quality control lab, reagent preparation lab, shipping and storage area and an office. Security and safety was a main consideration in the design of this PET pharmacy.

Current Practices and Trends in Mechanical Failure Prevention. Proceedings of the Meeting of the Mechanical Failures Prevention Group (44th) Held in Virginia Beach, Virginia 3-5 April 1990

DTIC Science & Technology

1990-01-01

become a sort of standard for the presence of microplasticity . What we have to realize is that both cleavage and MVC are larger scaled results of finer...34 Paper presented at Naval Sea Systems Command Magnetic Bearing Forum, Washington, D. C., July 1989. 11. Humphris, R. R., R. D. Kelm, D. W. Lewis and P. E...increasingly stringent. Several studies have pointed to the value of this concept. The revolution at sea SOCS study identified the need for and benefits of

Adaptive Vibration Reduction Controls for a Cryocooler With a Passive Balancer

NASA Technical Reports Server (NTRS)

Kopasakis, George; Cairelli, James E.; Traylor, Ryan M.

2001-01-01

In this paper an adaptive vibration reduction control (AVRC) design is described for a Stirling cryocooler combined with a passive balancer. The AVRC design was based on a mass-spring model of the cooler and balancer, and the AVRC algorithm described in this paper was based on an adaptive binary search. Results are shown comparing the baseline uncontrolled cooler with no balancer, the cooler with the balancer, and, finally, the cooler with the balancer and the AVRC. The comparison shows that it may be possible to meet stringent vibration reduction requirements without an active balancer.

The Installation of a P.E.T. Pharmacy at Washington University

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaehle, G.; Schwarz, S.; Mueller, M.

2003-08-26

Washington University has produced radioisotopes for medical application since the early 1960s. In order to serve seven PET scanners and to meet more stringent government regulations we have installed a new PET pharmacy based on our past years of experiences. The new pharmacy was installed at the site of the 3.7 MeV tandem cascade accelerator that was decommissioned in April of 2001. The pharmacy consists of a production lab, quality control lab, reagent preparation lab, shipping and storage area and an office. Security and safety was a main consideration in the design of this PET pharmacy.

75 FR 59469 - Energy Conservation Program: Energy Conservation Standards for Residential Refrigerators...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-27

...The Energy Policy and Conservation Act (EPCA) prescribes energy conservation standards for various consumer products and commercial and industrial equipment, including residential refrigerators, refrigerator-freezers, and freezers. EPCA also requires the U.S. Department of Energy (DOE) to determine whether more stringent, amended standards for these products are technologically feasible and economically justified, and would save a significant amount of energy. In this NOPR, DOE proposes amended energy conservation standards for residential refrigerators, refrigerator- freezers, and freezers. The NOPR also announces a public meeting to receive comment on these proposed standards and associated analyses and results.

78 FR 55889 - Energy Conservation Program: Energy Conservation Standards for Commercial Refrigeration Equipment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-11

...The Energy Policy and Conservation Act of 1975 (EPCA), as amended, prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including commercial refrigeration equipment (CRE). EPCA also requires the U.S. Department of Energy (DOE) to determine whether more-stringent, amended standards would be technologically feasible and economically justified, and would save a significant amount of energy. In this notice, DOE proposes amended energy conservation standards for commercial refrigeration equipment. The notice also announces a public meeting to receive comment on these proposed standards and associated analyses and results.

Project Cerberus: Flyby Mission to Pluto

NASA Technical Reports Server (NTRS)

Sivier, K.; Koepke, A.; Humphrey, Theodore W.; Elbel, Jeffrey P.; Hackett, Bruce E.; Kennedy, Ralph G.; Leo, Donald J.; Zimmerman, Shery A.

1990-01-01

The goal of the Cerberus Project was to design a feasible and cost-effective unmanned flyby mission to Pluto. The requirements in the request for proposal for an unmanned probe to Pluto are presented and were met. The design stresses proven technology that will avoid show stoppers which could halt mission progress. Cerberus also utilizes the latest advances in the spacecraft industry to meet the stringent demands of the mission. The topics covered include: (1) mission management, planning, and costing; (2) structures; (3) power and propulsion; (4) attitude, articulation, and control; (5) command, control, and communication; and (6) scientific instrumentation.

Evaluation of Chemical Coating Processes for AXAF

NASA Technical Reports Server (NTRS)

Engelhaupt, Darell E.

1997-01-01

The need existed at MSFC for the development and fabrication of radioisotope calibration sources of cadmium 109 and iron 55 isotopes. This was in urgent response to the AXAF program. Several issues persisted in creating manufacturing difficulties for the supplier. In order to meet the MSFC requirements very stringent control needed to be maintained for the coating quality, specific activity and thickness. Due to the difficulties in providing the precisely controlled devices for testing, the delivery of the sources was seriously delayed. It became imperative that these fabrication issues be resolved to avoid further delays in this AXAF observatory key component.

Accuracy of Surgery Clerkship Performance Raters.

ERIC Educational Resources Information Center

Littlefield, John H.; And Others

1991-01-01

Interrater reliability in numerical ratings of clerkship performance (n=1,482 students) in five surgery programs was studied. Raters were classified as accurate or moderately or significantly stringent or lenient. Results indicate that increasing the proportion of accurate raters would substantially improve the precision of class rankings. (MSE)

Building America Case Study: Evaluation of Ventilation Strategies in New Construction Multifamily Buildings, New York, New York (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2014-09-01

In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the 'fresh' air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the 'normal leakage paths through the building envelope' disappear. CARB researchers have found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air tomore » apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. Product performance data are based on laboratory tests, and the assumption is that products will perform similarly in the field. Proper application involves matching expected performance at expected building pressures, but there is no guarantee that those conditions will exist consistently in the finished building. This research effort, which included several weeks of building pressure monitoring, sought to provide field validation of system performance. The performance of four substantially different strategies for providing make-up air to apartments was evaluated.« less

Comparison of steady-state and transient CVS cycle emission of an automotive Stirling engine

NASA Technical Reports Server (NTRS)

Farrell, R. A.; Bolton, R. J.

1983-01-01

The Automotive Stirling Engine Development Program is to demonstrate a number of goals for a Stirling-powered vehicle. These goals are related to an achievement of specified maximum emission rates, a combined cycle fuel economy 30 percent better than a comparable internal-combustion engine-powered automobile, multifuel capability, competitive cost and reliability, and a meeting of Federal standards concerning noise and safety. The present investigation is concerned with efforts related to meeting the stringent emission goals. Attention is given to the initial development of a procedure for predicting transient CVS urban cycle gaseous emissions from steady-state engine data, taking into account the employment of the test data from the first-generation automotive Stirling engine. A large amount of steady-state data from three Mod I automotive Stirling engines were used to predict urban CVS cycle emissions for the Mod I Lerma vehicle.

Power system characteristics for more electric aircraft

NASA Technical Reports Server (NTRS)

Hansen, Irving G.

1993-01-01

It should not be suprising that more electric aircraft must meet significantly more difficult electrical power system requirements than were considereed when today's power distribution systems were being developed. Electric power, no longer a secondary system, will become a critical element of the primary control system. Functional reliability requiirements will be extremely stringent and can only be met by controlling element redundancy within a distributed power system. Existing electrical systems were not developed to have both the power system and the control/sensing elements distributed and yet meet the requirements of lighting tolerance and high intensity radio frequency (HIRF). In addition, the operation of electric actuators involves high transient loading and reverse energy flows. Such phenomena were also not anticipated when power quality was specified for either 270 vdc or 400 Hertz ac power systems. This paper will expand upon the issues and discuss some of the technologies involved in their resolution.

Advanced Launch System (ALS) actuation and power systems impact operability and cost

NASA Technical Reports Server (NTRS)

Sundberg, Gale R.

1990-01-01

To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications.

Advanced Launch System (ALS): Electrical actuation and power systems improve operability and cost picture

NASA Technical Reports Server (NTRS)

Sundberg, Gale R.

1990-01-01

To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrical power system and controls for all actuation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a specific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military and civilian aircraft, lunar/Martian vehicles, and a multitude of commercial applications.

Advanced launch system (ALS) - Electrical actuation and power systems improve operability and cost picture

NASA Technical Reports Server (NTRS)

Sundberg, Gale R.

1990-01-01

To obtain the Advanced Launch System (ALS) primary goals of reduced costs and improved operability, there must be significant reductions in the launch operations and servicing requirements relative to current vehicle designs and practices. One of the primary methods for achieving these goals is by using vehicle electrrical power system and controls for all aviation and avionics requirements. A brief status review of the ALS and its associated Advanced Development Program is presented to demonstrate maturation of those technologies that will help meet the overall operability and cost goals. The electric power and actuation systems are highlighted as a sdpecific technology ready not only to meet the stringent ALS goals (cryogenic field valves and thrust vector controls with peak power demands to 75 hp), but also those of other launch vehicles, military ans civilian aircraft, lunar/Martian vehicles, and a multitude of comercial applications.

KSC-06pd0783

NASA Image and Video Library

2006-04-28

KENNEDY SPACE CENTER, FLA. - Dwayne Light (left), director of Florida Operations, Astrotech, assists Jim Adams, deputy project manager for NASA's Solar Terrestrial Relations Observatory (STEREO), Goddard Space Flight Center, as he cuts the ribbon to officially open the new class 10,000 clean-room enclosure at Astrotech, a payload processing facility near Kennedy Space Center. This clean-room enclosure, within the high bay at Astrotech, meets the additional stringent cleanliness requirements necessary for processing STEREO for launch. The enclosure was designed and constructed by Astrotech to meet the spacecraft requirements provided by STEREO project management at NASA's Goddard Space Flight Center, Greenbelt, Md. STEREO consists of two spacecraft whose mission is the first to take measurements of the sun and solar wind in 3-D. Launch aboard a Boeing Delta II rocket from Launch Complex 17 on Cape Canaveral Air Force Station is scheduled to occur over the summer. Photo credit: NASA/Dimitri Gerondidakis

KSC-06pd0782

NASA Image and Video Library

2006-04-28

KENNEDY SPACE CENTER, FLA. - Jim Adams (right), deputy project manager for NASA's Solar Terrestrial Relations Observatory (STEREO), Goddard Space Flight Center, presents a certificate of appreciation to Dwayne Light, director of Florida Operations, Astrotech, a payload processing facility near Kennedy Space Center. The occasion was the ribbon-cutting for a clean-room enclosure, within the high bay at Astrotech. The enclosure meets the additional stringent cleanliness requirements necessary for processing STEREO for launch. It was designed and constructed by Astrotech to meet the spacecraft requirements provided by STEREO project management at NASA's Goddard Space Flight Center, Greenbelt, Md. STEREO consists of two spacecraft whose mission is the first to take measurements of the sun and solar wind in 3-D. Launch aboard a Boeing Delta II rocket from Launch Complex 17 on Cape Canaveral Air Force Station is scheduled to occur over the summer. Photo credit: NASA/Dimitri Gerondidakis

Advanced Turbo-Charging Research and Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2008-02-27

The objective of this project is to conduct analysis, design, procurement and test of a high pressure ratio, wide flow range, and high EGR system with two stages of turbocharging. The system needs to meet the stringent 2010MY emissions regulations at 20% + better fuel economy than its nearest gasoline competitor while allowing equivalent vehicle launch characteristics and higher torque capability than its nearest gasoline competitor. The system will also need to meet light truck/ SUV life requirements, which will require validation or development of components traditionally used only in passenger car applications. The conceived system is termed 'seriessequential turbocharger'more » because the turbocharger system operates in series at appropriate times and also sequentially when required. This is accomplished using intelligent design and control of flow passages and valves. Components of the seriessequential system will also be applicable to parallel-sequential systems which are also expected to be in use for future light truck/SUV applications.« less

Detecting Chemical Weapons: Threats, Requirements, Solutions, and Future Challenges

NASA Astrophysics Data System (ADS)

Boso, Brian

2011-03-01

Although chemicals have been reportedly used as weapons for thousands of years, it was not until 1915 at Ypres, France that an industrial chemical, chlorine, was used in World War I as an offensive weapon in significant quantity, causing mass casualties. From that point until today the development, detection, production and protection from chemical weapons has be an organized endeavor of many of the world's armed forces and in more recent times, non-governmental terrorist organizations. The number of Chemical Warfare Agents (CWAs) has steadily increased as research into more toxic substances continued for most of the 20 th century. Today there are over 70 substances including harassing agents like tear gas, incapacitating agents, and lethal agents like blister, blood, chocking, and nerve agents. The requirements for detecting chemical weapons vary depending on the context in which they are encountered and the concept of operation of the organization deploying the detection equipment. The US DoD, for example, has as a requirement, that US forces be able to continue their mission, even in the event of a chemical attack. This places stringent requirements on detection equipment. It must be lightweight (<2 lbs), detect a large array of chemical warfare agents and toxic industrial chemicals, detect and warn at concentration levels and time duration to prevent acute health effects, meet military ruggedness specifications and work over a wide range of temperature and humidity, and have a very high probability of detection with a similarly low probability of false positives. The current technology of choice to meet these stringent requirements is Ion Mobility Spectrometry. Many technologies are capable of detecting chemicals at the trace levels required and have been extensively developed for this application, including, but not limited to: mass spectroscopy, IR spectroscopy, RAMAN spectroscopy, MEMs micro-cantilever sensors, surface acoustic wave sensors, differential mobility spectrometry, and amplifying fluorescence polymers. In the future the requirements for detection equipment will continue to become even more stringent. The continuing increase in the sheer number of threats that will need to be detected, the development of binary agents requiring that even the precursor chemicals be detected, the development of new types of agents unlike any of the current chemistries, and the expansion of the list of toxic industrial chemical will require new techniques with higher specificity and more sensitivity.

Direct digital RF synthesis and modulation for MSAT mobile applications

NASA Technical Reports Server (NTRS)

Crozier, Stewart; Datta, Ravi; Sydor, John

1993-01-01

A practical method of performing direct digital RF synthesis using the Hilbert transform single sideband (SSB) technique is described. It is also shown that amplitude and phase modulation can be achieved directly at L-band with frequency stability and spurii performance exceeding stringent MSAT system requirements.

Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (p)ppGpp synthase

PubMed Central

Brockmann-Gretza, Olaf; Kalinowski, Jörn

2006-01-01

Background The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides (p)ppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize (p)ppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX) in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be responsible for the complex transcriptional patterns detected in the rel mutant when compared directly with its rel-proficient parent strain. Conclusion In C. glutamicum the stringent response enfolds a fast answer to an induced amino acid starvation on the transcriptome level. It also showed some significant differences to the transcriptional reactions occuring in Escherichia coli and Bacillus subtilis. Notable are the rel-dependent regulation of the nitrogen metabolism genes and the rel-independent regulation of the genes encoding ribosomal proteins. PMID:16961923

Incidence of Enuresis and Encopresis Among Children with Attention Deficit Hyperactivity Disorder in a Population-Based Birth Cohort

PubMed Central

Mellon, Michael W.; Natchev, Brooke E.; Katusic, Slavica K.; Colligan, Robert C.; Weaver, Amy L.; Voigt, Robert G.; Barbaresi, William J.

2013-01-01

OBJECTIVE This study reports the incidence of enuresis and encopresis among children with attention-deficit/hyperactivity disorder (AD/HD) versus those without AD/HD. METHOD Subjects included 358 (74.5% male) children with research-identified AD/HD from a 1976-1982 population-based birth cohort (N = 5718) and 729 (75.2% male) non-AD/HD control subjects from the same birth cohort, matched by gender and age. All subjects were retrospectively followed from birth until a diagnosis of enuresis or encopresis was made or last follow-up prior to 18 years of age. The complete medical record for each subject was reviewed to obtain information on age of initial diagnosis of an elimination disorder, frequency and duration of symptoms, identification of exclusionary criteria specified by DSM-IV, with confirmation of the diagnosis by expert consensus. RESULTS Children with AD/HD were 2.1 (95% CI, 1.3-3.4; p = 0.002) times more likely to meet DSM-IV criteria for enuresis than non-AD/HD controls; they were 1.8 (95% CI, 1.2 – 2.7; p = 0.006) times more likely to do so than non-AD/HD controls when less stringent criteria for a diagnosis of enuresis were employed. Though not significant, children with AD/HD were 1.8 (95% CI, 0.7-4.6; p = 0.23) times more likely to meet criteria for encopresis than non-AD/HD controls. The relative risk was 2.0 (95% CI, 1.0-4.1; p = 0.05) when a less stringent definition for encopresis was utilized. CONCLUSIONS The results of this population-based study demonstrate that children with AD/HD are more likely than their peers without AD/HD to develop enuresis with a similar trend for encopresis. PMID:23680296

Incidence of enuresis and encopresis among children with attention-deficit/hyperactivity disorder in a population-based birth cohort.

PubMed

Mellon, Michael W; Natchev, Brooke E; Katusic, Slavica K; Colligan, Robert C; Weaver, Amy L; Voigt, Robert G; Barbaresi, William J

2013-01-01

This study reports the incidence of enuresis and encopresis among children with attention-deficit/hyperactivity disorder (ADHD) versus those without ADHD. Subjects included 358 children (74.5% boys) with research-identified ADHD from a 1976 to 1982 population-based birth cohort (n = 5718) and 729 (75.2% boys) non-ADHD control subjects from the same birth cohort, matched by gender and age. All subjects were retrospectively followed from birth until a diagnosis of enuresis or encopresis was made or last follow-up before 18 years of age. The complete medical record for each subject was reviewed to obtain information on age of initial diagnosis of an elimination disorder, frequency and duration of symptoms, and identification of exclusionary criteria specified by DSM-IV, with confirmation of the diagnosis by expert consensus. Children with ADHD were 2.1 (95% confidence interval [CI], 1.3-3.4; P = .002) times more likely to meet DSM-IV criteria for enuresis than non-ADHD controls; they were 1.8 (95% CI, 1.2-2.7; P = .006) times more likely to do so than non-ADHD controls when less stringent criteria for a diagnosis of enuresis were employed. Though not significant, children with ADHD were 1.8 (95% CI, 0.7-4.6; P = .23) times more likely to meet criteria for encopresis than non-ADHD controls. The relative risk was 2.0 (95% CI, 1.0-4.1; P = .05) when a less stringent definition for encopresis was utilized. Children with ADHD are more likely than their peers without ADHD to develop enuresis with a similar trend for encopresis. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Analysis of multiuser mixed RF/FSO relay networks for performance improvements in Cloud Computing-Based Radio Access Networks (CC-RANs)

NASA Astrophysics Data System (ADS)

Alimi, Isiaka A.; Monteiro, Paulo P.; Teixeira, António L.

2017-11-01

The key paths toward the fifth generation (5G) network requirements are towards centralized processing and small-cell densification systems that are implemented on the cloud computing-based radio access networks (CC-RANs). The increasing recognitions of the CC-RANs can be attributed to their valuable features regarding system performance optimization and cost-effectiveness. Nevertheless, realization of the stringent requirements of the fronthaul that connects the network elements is highly demanding. In this paper, considering the small-cell network architectures, we present multiuser mixed radio-frequency/free-space optical (RF/FSO) relay networks as feasible technologies for the alleviation of the stringent requirements in the CC-RANs. In this study, we use the end-to-end (e2e) outage probability, average symbol error probability (ASEP), and ergodic channel capacity as the performance metrics in our analysis. Simulation results show the suitability of deployment of mixed RF/FSO schemes in the real-life scenarios.

Stringency and relaxation among the halobacteria.

PubMed Central

Cimmino, C; Scoarughi, G L; Donini, P

1993-01-01

Accumulation of stable RNA and production of guanosine polyphosphates (ppGpp and pppGpp) were studied during amino acid starvation in four species of halobacteria. In two of the four species, stable RNA was under stringent control, whereas one of the remaining two species was relaxed and the other gave an intermediate phenotype. The stringent reaction was reversed by anisomycin, an effect analogous to the chloroamphenicol-induced reversal of stringency in the eubacteria. During the stringent response, neither ppGpp nor pppGpp accumulation took place during starvation. In both growing and starved cells a very low basal level of the two polyphosphates appeared to be present. In the stringent species the intracellular concentration of GTP did not diminish but actually increased during the course of the stringent response. These data demonstrate that (i) wild-type halobacteria can have either the stringent or the relaxed phenotype (all wild-type eubacteria tested have been shown to be stringent); (ii) stringency in the halobacteria is dependent on the deaminoacylation of tRNA, as in the eubacteria; and (iii) in the halobacteria, ppGpp is not an effector of stringent control over stable-RNA synthesis. Images PMID:7691798

75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-19

... noted that the limit for baked extreme performance coatings in the rule is less stringent than the limit... the VOC limit for baked extreme performance coatings and the exemption for repair and touch-up operations. As to the emission limit for baked extreme performance coatings, the VOC limit in Rule 4603 is...

Energy Efficient Engine combustor test hardware detailed design report

NASA Technical Reports Server (NTRS)

Burrus, D. L.; Chahrour, C. A.; Foltz, H. L.; Sabla, P. E.; Seto, S. P.; Taylor, J. R.

1984-01-01

The Energy Efficient Engine (E3) Combustor Development effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent was to evolve a design which meets the stringent emissions and life goals of the E3 as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this development effort will be incorporated into the engine combustion system hardware design. This advanced engine combustion system will then be evaluated in component testing to verify the design intent. What is evolving from this development effort is an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3. Fuel nozzle, diffuser, starting, and emissions design studies are discussed.

High Accuracy Transistor Compact Model Calibrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hembree, Charles E.; Mar, Alan; Robertson, Perry J.

2015-09-01

Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirementsmore » require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.« less

Future Automotive Aftertreatment Solutions: The 150°C Challenge Workshop Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zammit, Michael; DiMaggio, Craig L.; Kim, Chang H.

2013-10-15

With future fuel economy standards enacted, the U.S. automotive manufacturers (OEMs) are committed to pursuing a variety of high risk/highly efficient stoichiometric and lean combustion strategies to achieve superior performance. In recognition of this need, the U.S. Department of Energy (DOE) has partnered with domestic automotive manufacturers through U.S. DRIVE to develop these advanced technologies. However, before these advancements can be introduced into the U.S. market, they must also be able to meet increasingly stringent emissions requirements. A significant roadblock to this implementation is the inability of current catalyst and aftertreatment technologies to provide the required activity at the muchmore » lower exhaust temperatures that will accompany highly efficient combustion processes and powertrain strategies. Therefore, the goal of this workshop and report is to create a U.S. DRIVE emission control roadmap that will identify new materials and aftertreatment approaches that offer the potential for 90% conversion of emissions at low temperature (150°C) and are consistent with highly efficient combustion technologies currently under investigation within U.S. DRIVE Advanced Combustion and Emission Control (ACEC) programs.« less

Real-time vehicle emissions monitoring using a compact LiDAR system and conventional instruments: first results of an experimental campaign in a suburban area in southern Italy

NASA Astrophysics Data System (ADS)

Parracino, Stefano; Richetta, Maria; Gelfusa, Michela; Malizia, Andrea; Bellecci, Carlo; De Leo, Leonardo; Perrimezzi, Carlo; Fin, Alessandro; Forin, Marco; Giappicucci, Francesca; Grion, Massimo; Marchese, Giuseppe; Gaudio, Pasquale

2016-10-01

Urban air pollution causes deleterious effects on human health and the environment. To meet stringent standards imposed by the European Commission, advanced measurement methods are required. Remote sensing techniques, such as light detection and ranging (LiDAR), can be a valuable option for evaluating particulate matter (PM), emitted by vehicles in urban traffic, with high sensitivity and in shorter time intervals. Since air quality problems persist not only in large urban areas, a measuring campaign was specifically performed in a suburban area of Crotone, Italy, using both a compact LiDAR system and conventional instruments for real-time vehicle emissions monitoring along a congested road. First results reported in this paper show a strong dependence between variations of LiDAR backscattering signals and traffic-related air pollution levels. Moreover, time-resolved LiDAR data averaged in limited regions, directly above conventional monitoring stations at the border of an intersection, were found to be linearly correlated to the PM concentration levels with a correlation coefficient between 0.75 and 0.84.

ADX - Advanced Divertor and RF Tokamak Experiment

NASA Astrophysics Data System (ADS)

Greenwald, Martin; Labombard, Brian; Bonoli, Paul; Irby, Jim; Terry, Jim; Wallace, Greg; Vieira, Rui; Whyte, Dennis; Wolfe, Steve; Wukitch, Steve; Marmar, Earl

2015-11-01

The Advanced Divertor and RF Tokamak Experiment (ADX) is a design concept for a compact high-field tokamak that would address boundary plasma and plasma-material interaction physics challenges whose solution is critical for the viability of magnetic fusion energy. This device would have two crucial missions. First, it would serve as a Divertor Test Tokamak, developing divertor geometries, materials and operational scenarios that could meet the stringent requirements imposed in a fusion power plant. By operating at high field, ADX would address this problem at a level of power loading and other plasma conditions that are essentially identical to those expected in a future reactor. Secondly, ADX would investigate the physics and engineering of high-field-side launch of RF waves for current drive and heating. Efficient current drive is an essential element for achieving steady-state in a practical, power producing fusion device and high-field launch offers the prospect of higher efficiency, better control of the current profile and survivability of the launching structures. ADX would carry out this research in integrated scenarios that simultaneously demonstrate the required boundary regimes consistent with efficient current drive and core performance.

Membrane thickening aerobic digestion processes.

PubMed

Woo, Bryen

2014-01-01

Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

The design of an ultra-low sidelobe offset-fed 1.22m antenna for use in the broadcasting satellite service

NASA Technical Reports Server (NTRS)

Janky, J. M.

1981-01-01

A feed design and reflector geometry were determined for an ultra low sidelobe offset fed 1.22 meter antenna suitable for use in the 12 GHz broadcasting satellite service. Arbitrary constraints used to evaluate the relative merits of the feed horns and range of f/D geometries are: minimum efficiency of 55 percent, -30 dB first sidelobe level (relative to on axis gain), a 0 dBi plateau beyond the near in sidelobe region, and a Chebyshev polynomial based envelope (borrowed from filter theory) for the region from the -3 dB beamwidth points to the 0 dBi plateau region. This envelope is extremely stringent but the results of this research effort indicate that two steps of corrugated feed and a cluster array of small 1 lambda horns do meet the constraints. A set of performance specifications and a mechanical design suitable for a consumer oriented market in the broadcasting satellite service was developed. Costs for production quantities of 10,000 units/yr. are estimated to be around $150.

Cyber Safety and Security for Reduced Crew Operations (RCO)

NASA Technical Reports Server (NTRS)

Driscoll, Kevin R.; Roy, Aloke; Ponchak, Denise S.; Downey, Alan N.

2017-01-01

NASA and the Aviation Industry is looking into reduced crew operations (RCO) that would cut today's required two-person flight crews down to a single pilot with support from ground-based crews. Shared responsibility across air and ground personnel will require highly reliable and secure data communication and supporting automation, which will be safety-critical for passenger and cargo aircraft. This paper looks at the different types and degrees of authority delegation given from the air to the ground and the ramifications of each, including the safety and security hazards introduced, the mitigation mechanisms for these hazards, and other demands on an RCO system architecture which would be highly invasive into (almost) all safety-critical avionics. The adjacent fields of unmanned aerial systems and autonomous ground vehicles are viewed to find problems that RCO may face and related aviation accident scenarios are described. The paper explores possible data communication architectures to meet stringent performance and information security (INFOSEC) requirements of RCO. Subsequently, potential challenges for RCO data communication authentication, encryption and non-repudiation are identified.

Flight dynamics facility operational orbit determination support for the ocean topography experiment

NASA Technical Reports Server (NTRS)

Bolvin, D. T.; Schanzle, A. F.; Samii, M. V.; Doll, C. E.

1991-01-01

The Ocean Topography Experiment (TOPEX/POSEIDON) mission is designed to determine the topography of the Earth's sea surface across a 3 yr period, beginning with launch in June 1992. The Goddard Space Flight Center Dynamics Facility has the capability to operationally receive and process Tracking and Data Relay Satellite System (TDRSS) tracking data. Because these data will be used to support orbit determination (OD) aspects of the TOPEX mission, the Dynamics Facility was designated to perform TOPEX operational OD. The scientific data require stringent OD accuracy in navigating the TOPEX spacecraft. The OD accuracy requirements fall into two categories: (1) on orbit free flight; and (2) maneuver. The maneuver OD accuracy requirements are of two types; premaneuver planning and postmaneuver evaluation. Analysis using the Orbit Determination Error Analysis System (ODEAS) covariance software has shown that, during the first postlaunch mission phase of the TOPEX mission, some postmaneuver evaluation OD accuracy requirements cannot be met. ODEAS results also show that the most difficult requirements to meet are those that determine the change in the components of velocity for postmaneuver evaluation.

Reaction Wheel Disturbance Modeling, Jitter Analysis, and Validation Tests for Solar Dynamics Observatory

NASA Technical Reports Server (NTRS)

Liu,Kuo-Chia; Maghami, Peiman; Blaurock, Carl

2008-01-01

The Solar Dynamics Observatory (SDO) aims to study the Sun's influence on the Earth by understanding the source, storage, and release of the solar energy, and the interior structure of the Sun. During science observations, the jitter stability at the instrument focal plane must be maintained to less than a fraction of an arcsecond for two of the SDO instruments. To meet these stringent requirements, a significant amount of analysis and test effort has been devoted to predicting the jitter induced from various disturbance sources. One of the largest disturbance sources onboard is the reaction wheel. This paper presents the SDO approach on reaction wheel disturbance modeling and jitter analysis. It describes the verification and calibration of the disturbance model, and ground tests performed for validating the reaction wheel jitter analysis. To mitigate the reaction wheel disturbance effects, the wheels will be limited to operate at low wheel speeds based on the current analysis. An on-orbit jitter test algorithm is also presented in the paper which will identify the true wheel speed limits in order to ensure that the wheel jitter requirements are met.

Combining De Novo Peptide Sequencing Algorithms, A Synergistic Approach to Boost Both Identifications and Confidence in Bottom-up Proteomics.

PubMed

Blank-Landeshammer, Bernhard; Kollipara, Laxmikanth; Biß, Karsten; Pfenninger, Markus; Malchow, Sebastian; Shuvaev, Konstantin; Zahedi, René P; Sickmann, Albert

2017-09-01

Complex mass spectrometry based proteomics data sets are mostly analyzed by protein database searches. While this approach performs considerably well for sequenced organisms, direct inference of peptide sequences from tandem mass spectra, i.e., de novo peptide sequencing, oftentimes is the only way to obtain information when protein databases are absent. However, available algorithms suffer from drawbacks such as lack of validation and often high rates of false positive hits (FP). Here we present a simple method of combining results from commonly available de novo peptide sequencing algorithms, which in conjunction with minor tweaks in data acquisition ensues lower empirical FDR compared to the analysis using single algorithms. Results were validated using state-of-the art database search algorithms as well specifically synthesized reference peptides. Thus, we could increase the number of PSMs meeting a stringent FDR of 5% more than 3-fold compared to the single best de novo sequencing algorithm alone, accounting for an average of 11 120 PSMs (combined) instead of 3476 PSMs (alone) in triplicate 2 h LC-MS runs of tryptic HeLa digestion.

Large scale simulations of the mechanical properties of layered transition metal ternary compounds for fossil energy power system applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ching, Wai-Yim

2014-12-31

Advanced materials with applications in extreme conditions such as high temperature, high pressure, and corrosive environments play a critical role in the development of new technologies to significantly improve the performance of different types of power plants. Materials that are currently employed in fossil energy conversion systems are typically the Ni-based alloys and stainless steels that have already reached their ultimate performance limits. Incremental improvements are unlikely to meet the more stringent requirements aimed at increased efficiency and reduce risks while addressing environmental concerns and keeping costs low. Computational studies can lead the way in the search for novel materialsmore » or for significant improvements in existing materials that can meet such requirements. Detailed computational studies with sufficient predictive power can provide an atomistic level understanding of the key characteristics that lead to desirable properties. This project focuses on the comprehensive study of a new class of materials called MAX phases, or Mn+1AXn (M = a transition metal, A = Al or other group III, IV, and V elements, X = C or N). The MAX phases are layered transition metal carbides or nitrides with a rare combination of metallic and ceramic properties. Due to their unique structural arrangements and special types of bonding, these thermodynamically stable alloys possess some of the most outstanding properties. We used a genomic approach in screening a large number of potential MAX phases and established a database for 665 viable MAX compounds on the structure, mechanical and electronic properties and investigated the correlations between them. This database if then used as a tool for materials informatics for further exploration of this class of intermetallic compounds.« less

Environmental, health, and safety issues of fuel cells in transportation. Volume 1: Phosphoric acid fuel-cell buses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ring, S

1994-12-01

The U.S. Department of Energy (DOE) chartered the Phosphoric Acid Fuel-Cell (PAFC) Bus Program to demonstrate the feasibility of fuel cells in heavy-duty transportation systems. As part of this program, PAFC- powered buses are being built to meet transit industry design and performance standards. Test-bed bus-1 (TBB-1) was designed in 1993 and integrated in March 1994. TBB-2 and TBB-3 are under construction and should be integrated in early 1995. In 1987 Phase I of the program began with the development and testing of two conceptual system designs- liquid- and air-cooled systems. The liquid-cooled PAFC system was chosen to continue, throughmore » a competitive award, into Phase H, beginning in 1991. Three hybrid buses, which combine fuel-cell and battery technologies, were designed during Phase III. After completing Phase II, DOE plans a comprehensive performance testing program (Phase HI) to verify that the buses meet stringent transit industry requirements. The Phase III study will evaluate the PAFC bus and compare it to a conventional diesel bus. This NREL study assesses the environmental, health, and safety (EH&S) issues that may affect the commercialization of the PAFC bus. Because safety is a critical factor for consumer acceptance of new transportation-based technologies the study focuses on these issues. The study examines health and safety together because they are integrally related. In addition, this report briefly discusses two environmental issues that are of concern to the Environmental Protection Agency (EPA). The first issue involves a surge battery used by the PAFC bus that contains hazardous constituents. The second issue concerns the regulated air emissions produced during operation of the PAFC bus.« less

TITLE: Environmental, health, and safety issues offuel cells in transportation. Volume 1: Phosphoricacid fuel-cell buses

NASA Astrophysics Data System (ADS)

Ring, Shan

1994-12-01

The U.S. Department of Energy (DOE) chartered the Phosphoric Acid Fuel-Cell (PAFC) Bus Program to demonstrate the feasibility of fuel cells in heavy-duty transportation systems. As part of this program, PAFC- powered buses are being built to meet transit industry design and performance standards. Test-bed bus-1 (TBB-1) was designed in 1993 and integrated in March 1994. TBB-2 and TBB-3 are under construction and should be integrated in early 1995. In 1987 Phase 1 of the program began with the development and testing of two conceptual system designs- liquid- and air-cooled systems. The liquid-cooled PAFC system was chosen to continue, through a competitive award, into Phase H, beginning in 1991. Three hybrid buses, which combine fuel-cell and battery technologies, were designed during Phase 3. After completing Phase 2, DOE plans a comprehensive performance testing program (Phase H1) to verify that the buses meet stringent transit industry requirements. The Phase 3 study will evaluate the PAFC bus and compare it to a conventional diesel bus. This NREL study assesses the environmental, health, and safety (EH&S) issues that may affect the commercialization of the PAFC bus. Because safety is a critical factor for consumer acceptance of new transportation-based technologies the study focuses on these issues. The study examines health and safety together because they are integrally related. In addition, this report briefly discusses two environmental issues that are of concern to the Environmental Protection Agency (EPA). The first issue involves a surge battery used by the PAFC bus that contains hazardous constituents. The second issue concerns the regulated air emissions produced during operation of the PAFC bus.

Sorbent Nanotechnologies for Water Cleaning

NASA Astrophysics Data System (ADS)

Ahmed, Snober

Despite decades of regulatory efforts to mitigate water pollution, many chemicals, particularly heavy metals, still present risks to human health. In addition to direct exposure, certain metals such as mercury threaten public health due to its persistence, bioaccumulation and bioamplification throughout the food chain. A number of U.S. Federal and State regulations have been established to reduce the levels of mercury in water. Activated carbon (AC) has been widely explored for the removal of mercury. However, AC suffers from many limitations inherent to its chemical properties, and it becomes increasingly challenging to meet current and future regulations by simply modifying AC to enhance its performance. Recently, the performance of nanosorbents have been studied in order to removal pollutants. Nanosorbents utilize the ultra-high reactive surface of nanoparticles for rapid, effective and even permanent sequestration of heavy metals from water and air, thus showed promising results as compared to AC. The goal of this thesis research is to develop nanomaterial-based sorbents for the removal of mercury from water. It describes the development of a new solid-support assisted growth of selenium nanoparticles, their use for water remediation, and the development of a new nanoselenium-based sorbent sponge for fast and efficient mercury removal. The nanoselenium sorbent not only shows irreversible interaction with mercury but also exhibits remarkable properties by overcoming the limitations of AC. The nanoselenium sponge was shown to remove mercury to undetectable levels within one minute. This new sponge technology would have an impact on inspiring new stringent regulations and lowering costs to help industries meet regulatory requirements, which will ultimately help improve air and water quality, aquatic life and public health.

Polymeric additive performance in closed whitewater systems

Treesearch

T. H. Wegner

1984-01-01

“With more stringent requirements on discharge water quality and with escalating water treatment costs, water recycling within the paper mill is of growing importance. A serious problem resulting from more white-water recycling is reduced drainage and fiber or fines retention because of diminished polymeric additive performance. To provide better insight for overcoming...

Development of a 10 Ah, Prismatic, Lithium-Ion Cell for NASA/GSFC

NASA Technical Reports Server (NTRS)

Stein, Brian; Baker, John W.; George, Douglas S.; Isaacs, Nathan D.; Shah, Pinakin M.; Rao, Gopalakrishna M.; Day, John H. (Technical Monitor)

2001-01-01

MSA's 10 Ah Li-ion cell is a rugged design suitable for the stringent requirements of aerospace applications. Eighteen cells demonstrate consistent cycling performance over a wide range of rates and temperatures. The cell passes qualification requirements for vibration survivability technology improvements at MSA continue to enhance cell performance.

Do we need a special ethics for research?

PubMed

Hansson, Sven Ove

2011-03-01

Research is subject to more stringent ethical requirements than most other human activities, and a procedure that is otherwise allowed may be forbidden in research. Hence, risk-taking is more restricted in scientific research than in most non-research contexts, and privacy is better protected in scientific questionnaires than in marketing surveys. Potential arguments for this difference are scrutinized. The case in its favour appears to be weak. A stronger case can be made in favour of a difference in the opposite direction: If perilous or otherwise problematic activities have to be performed it is usually better to perform them in a research context where they are properly evaluated so that guidance is obtained for the future. However, retreating from current ethical demands on research is not a desirable direction to go. Instead, research ethics can serve to inspire the introduction of more stringent ethical principles in other social sectors.

Optical Breath Gas Sensor for Extravehicular Activity Application

NASA Technical Reports Server (NTRS)

Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S.; Chullen, Cinda; Falconi, Eric A.; McMillin, Summer

2013-01-01

The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

78 FR 55781 - Energy Conservation Program: Energy Conservation Standards for Walk-In Coolers and Freezers

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-11

...The Energy Policy and Conservation Act of 1975 (EPCA), as amended, prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including walk-in coolers and walk-in freezers. EPCA also requires the U.S. Department of Energy (DOE) to determine whether more-stringent, amended standards would be technologically feasible and economically justified, and would save a significant amount of energy. In this notice, DOE proposes amended energy conservation standards for walk-in coolers and walk-in freezers. The notice also announces a public meeting to receive comment on these proposed standards and associated analyses and results.

Propagating Qualitative Values Through Quantitative Equations

NASA Technical Reports Server (NTRS)

Kulkarni, Deepak

1992-01-01

In most practical problems where traditional numeric simulation is not adequate, one need to reason about a system with both qualitative and quantitative equations. In this paper, we address the problem of propagating qualitative values represented as interval values through quantitative equations. Previous research has produced exponential-time algorithms for approximate solution of the problem. These may not meet the stringent requirements of many real time applications. This paper advances the state of art by producing a linear-time algorithm that can propagate a qualitative value through a class of complex quantitative equations exactly and through arbitrary algebraic expressions approximately. The algorithm was found applicable to Space Shuttle Reaction Control System model.

Mission Management Computer Software for RLV-TD

NASA Astrophysics Data System (ADS)

Manju, C. R.; Joy, Josna Susan; Vidya, L.; Sheenarani, I.; Sruthy, C. N.; Viswanathan, P. C.; Dinesh, Sudin; Jayalekshmy, L.; Karuturi, Kesavabrahmaji; Sheema, E.; Syamala, S.; Unnikrishnan, S. Manju; Ali, S. Akbar; Paramasivam, R.; Sheela, D. S.; Shukkoor, A. Abdul; Lalithambika, V. R.; Mookiah, T.

2017-12-01

The Mission Management Computer (MMC) software is responsible for the autonomous navigation, sequencing, guidance and control of the Re-usable Launch Vehicle (RLV), through lift-off, ascent, coasting, re-entry, controlled descent and splashdown. A hard real-time system has been designed for handling the mission requirements in an integrated manner and for meeting the stringent timing constraints. Redundancy management and fault-tolerance techniques are also built into the system, in order to achieve a successful mission even in presence of component failures. This paper describes the functions and features of the components of the MMC software which has accomplished the successful RLV-Technology Demonstrator mission.

Realization of the Contextuality-Nonlocality Tradeoff with a Qubit-Qutrit Photon Pair

NASA Astrophysics Data System (ADS)

Zhan, Xiang; Zhang, Xin; Li, Jian; Zhang, Yongsheng; Sanders, Barry C.; Xue, Peng

2016-03-01

We report our experimental results on the no-disturbance principle, which imposes a fundamental monogamy relation on contextuality versus nonlocality. We employ a photonic qutrit-qubit hybrid to explore no-disturbance monogamy at the quantum boundary spanned by noncontextuality and locality inequalities. In particular, we realize the single point where the quantum boundary meets the no-disturbance boundary. Our results agree with quantum theory and satisfy the stringent monogamy relation thereby providing direct experimental evidence of a tradeoff between locally contextual correlations and spatially separated correlations. Thus, our experiment provides evidence that entanglement is a particular manifestation of a more fundamental quantum resource.

Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

2003-01-01

A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

Vision-Aided RAIM: A New Method for GPS Integrity Monitoring in Approach and Landing Phase

PubMed Central

Fu, Li; Zhang, Jun; Li, Rui; Cao, Xianbin; Wang, Jinling

2015-01-01

In the 1980s, Global Positioning System (GPS) receiver autonomous integrity monitoring (RAIM) was proposed to provide the integrity of a navigation system by checking the consistency of GPS measurements. However, during the approach and landing phase of a flight path, where there is often low GPS visibility conditions, the performance of the existing RAIM method may not meet the stringent aviation requirements for availability and integrity due to insufficient observations. To solve this problem, a new RAIM method, named vision-aided RAIM (VA-RAIM), is proposed for GPS integrity monitoring in the approach and landing phase. By introducing landmarks as pseudo-satellites, the VA-RAIM enriches the navigation observations to improve the performance of RAIM. In the method, a computer vision system photographs and matches these landmarks to obtain additional measurements for navigation. Nevertheless, the challenging issue is that such additional measurements may suffer from vision errors. To ensure the reliability of the vision measurements, a GPS-based calibration algorithm is presented to reduce the time-invariant part of the vision errors. Then, the calibrated vision measurements are integrated with the GPS observations for integrity monitoring. Simulation results show that the VA-RAIM outperforms the conventional RAIM with a higher level of availability and fault detection rate. PMID:26378533

Vision-Aided RAIM: A New Method for GPS Integrity Monitoring in Approach and Landing Phase.

PubMed

Fu, Li; Zhang, Jun; Li, Rui; Cao, Xianbin; Wang, Jinling

2015-09-10

In the 1980s, Global Positioning System (GPS) receiver autonomous integrity monitoring (RAIM) was proposed to provide the integrity of a navigation system by checking the consistency of GPS measurements. However, during the approach and landing phase of a flight path, where there is often low GPS visibility conditions, the performance of the existing RAIM method may not meet the stringent aviation requirements for availability and integrity due to insufficient observations. To solve this problem, a new RAIM method, named vision-aided RAIM (VA-RAIM), is proposed for GPS integrity monitoring in the approach and landing phase. By introducing landmarks as pseudo-satellites, the VA-RAIM enriches the navigation observations to improve the performance of RAIM. In the method, a computer vision system photographs and matches these landmarks to obtain additional measurements for navigation. Nevertheless, the challenging issue is that such additional measurements may suffer from vision errors. To ensure the reliability of the vision measurements, a GPS-based calibration algorithm is presented to reduce the time-invariant part of the vision errors. Then, the calibrated vision measurements are integrated with the GPS observations for integrity monitoring. Simulation results show that the VA-RAIM outperforms the conventional RAIM with a higher level of availability and fault detection rate.

Use of high performance networks and supercomputers for real-time flight simulation

NASA Technical Reports Server (NTRS)

Cleveland, Jeff I., II

1993-01-01

In order to meet the stringent time-critical requirements for real-time man-in-the-loop flight simulation, computer processing operations must be consistent in processing time and be completed in as short a time as possible. These operations include simulation mathematical model computation and data input/output to the simulators. In 1986, in response to increased demands for flight simulation performance, NASA's Langley Research Center (LaRC), working with the contractor, developed extensions to the Computer Automated Measurement and Control (CAMAC) technology which resulted in a factor of ten increase in the effective bandwidth and reduced latency of modules necessary for simulator communication. This technology extension is being used by more than 80 leading technological developers in the United States, Canada, and Europe. Included among the commercial applications are nuclear process control, power grid analysis, process monitoring, real-time simulation, and radar data acquisition. Personnel at LaRC are completing the development of the use of supercomputers for mathematical model computation to support real-time flight simulation. This includes the development of a real-time operating system and development of specialized software and hardware for the simulator network. This paper describes the data acquisition technology and the development of supercomputing for flight simulation.

Highly Efficient Deep Blue Organic Light-Emitting Diodes Based on Imidazole: Significantly Enhanced Performance by Effective Energy Transfer with Negligible Efficiency Roll-off.

PubMed

Shan, Tong; Liu, Yulong; Tang, Xiangyang; Bai, Qing; Gao, Yu; Gao, Zhao; Li, Jinyu; Deng, Jian; Yang, Bing; Lu, Ping; Ma, Yuguang

2016-10-26

Great efforts have been devoted to develop efficient deep blue organic light-emitting diodes (OLEDs) materials meeting the standards of European Broadcasting Union (EBU) standard with Commission International de L'Eclairage (CIE) coordinates of (0.15, 0.06) for flat-panel displays and solid-state lightings. However, high-performance deep blue OLEDs are still rare for applications. Herein, two efficient deep blue emitters, PIMNA and PyINA, are designed and synthesized by coupling naphthalene with phenanthreneimidazole and pyreneimidazole, respectively. The balanced ambipolar transporting natures of them are demonstrated by single-carrier devices. Their nondoped OLEDs show deep blue emissions with extremely small CIE y of 0.034 for PIMNA and 0.084 for PyINA, with negligible efficiency roll-off. To take advantage of high photoluminescence quantum efficiency of PIMNA and large fraction of singlet exciton formation of PyINA, doped devices are fabricated by dispersing PyINA into PIMNA. A significantly improved maximum external quantum efficiency (EQE) of 5.05% is obtained through very effective energy transfer with CIE coordinates of (0.156, 0.060), and the EQE remains 4.67% at 1000 cd m -2 , which is among the best of deep blue OLEDs reported matching stringent EBU standard well.

Unique Systems Analysis Task 7, Advanced Subsonic Technologies Evaluation Analysis

NASA Technical Reports Server (NTRS)

Eisenberg, Joseph D. (Technical Monitor); Bettner, J. L.; Stratton, S.

2004-01-01

To retain a preeminent U.S. position in the aircraft industry, aircraft passenger mile costs must be reduced while at the same time, meeting anticipated more stringent environmental regulations. A significant portion of these improvements will come from the propulsion system. A technology evaluation and system analysis was accomplished under this task, including areas such as aerodynamics and materials and improved methods for obtaining low noise and emissions. Previous subsonic evaluation analyses have identified key technologies in selected components for propulsion systems for year 2015 and beyond. Based on the current economic and competitive environment, it is clear that studies with nearer turn focus that have a direct impact on the propulsion industry s next generation product are required. This study will emphasize the year 2005 entry into service time period. The objective of this study was to determine which technologies and materials offer the greatest opportunities for improving propulsion systems. The goals are twofold. The first goal is to determine an acceptable compromise between the thermodynamic operating conditions for A) best performance, and B) acceptable noise and chemical emissions. The second goal is the evaluation of performance, weight and cost of advanced materials and concepts on the direct operating cost of an advanced regional transport of comparable technology level.

Optical Breath Gas Extravehicular Activity Sensor for the Advanced Portable Life Support System

NASA Technical Reports Server (NTRS)

Wood, William R.; Casias, Miguel E.; Pilgrim, Jeffrey S.; Chullen, Cinda; Campbell, Colin

2016-01-01

The infrared gas transducer used during extravehicular activity (EVA) in the extravehicular mobility unit (EMU) measures and reports the concentration of carbon dioxide (CO2) in the ventilation loop. It is nearing its end of life and there are a limited number remaining. Meanwhile, the next generation advanced portable life support system (PLSS) now being developed requires CO2 sensing technology with performance beyond that presently in use. A laser diode (LD) spectrometer based on wavelength modulation spectroscopy (WMS) is being developed to address both applications by Vista Photonics, Inc. Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. Version 1.0 devices were delivered to NASA Johnson Space Center (JSC) in 2011. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement. The prototypes are controlled digitally with a field-programmable gate array (FPGA)/microcontroller architecture. Version 2.0 devices with improved electronics and significantly reduced wetted volumes were delivered to JSC in 2012. A version 2.5 upgrade recently implemented wavelength stabilized operation, better humidity measurement, and much faster data analysis/reporting. A wholly reconfigured version 3.0 will maintain the demonstrated performance of earlier versions while being backwards compatible with the EMU and offering a radiation tolerant architecture.

Resolution of the direct containment heating issue for all Westinghouse plants with large dry containments or subatmospheric containments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilch, M.M.; Allen, M.D.; Klamerus, E.W.

1996-02-01

This report uses the scenarios described in NUREG/CR-6075 and NUREG/CR-6075, Supplement 1, to address the direct containment heating (DCH) issue for all Westinghouse plants with large dry or subatmospheric containments. DCH is considered resolved if the conditional containment failure probability (CCFP) is less than 0.1. Loads versus strength evaluations of the CCFP were performed for each plant using plant-specific information. The DCH issue is considered resolved for a plant if a screening phase results in a CCFP less than 0.01, which is more stringent than the overall success criterion. If the screening phase CCFP for a plant is greater thanmore » 0.01, then refined containment loads evaluations must be performed and/or the probability of high pressure at vessel breach must be analyzed. These analyses could be used separately or could be integrated together to recalculate the CCFP for an individual plant to reduce the CCFP to meet the overall success criterion of less than 0.1. The CCFPs for all of the Westinghouse plants with dry containments were less than 0.01 at the screening phase, and thus, the DCH issue is resolved for these plants based on containment loads alone. No additional analyses are required.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinzey, Bruce R.; Royer, Michael P.; Hadjian, M.

Nine different streetlighting products were installed on various streets in Kansas City, Missouri during February, 2011, to evaluate their performance relative to the incumbent high-pressure sodium (HPS) lighting. The applications investigated included 100 W, 150 W, 250 W, and 400 W HPS installations. Initial measurements and comparisons included power, illuminance, and luminance; sample illuminance readings have continued at each of the nine locations at roughly 1,000-hour operating intervals since then. All of the LED products consumed less power than their HPS counterparts—with a mean difference of 39% and a range of 31% to 51%—but they also emitted 31% fewer lumens,more » on average. The net result is just a 15% increase in mean efficacy. Applying the city’s stringent light loss factors to the initial measured data meant that five of the LED products (and two of the HPS luminaires) were predicted to eventually fail to meet the specified mean illuminance over their lifetimes; however, the specified light loss levels are not expected to be reached by the LED products until some distant future date (between 12 and 30 years after installation according to manufacturer specification sheet estimates). The practical value of designing streetlighting systems to meet illumination requirements more than 15 years in the future is questioned. Numerous sources of variation in field measurements are noted throughout the report, particularly seasonal influences such as ambient temperature and foliage that are evident in the time-series illuminance data.« less

USABC Development of 12 Volt Battery for Start-Stop Application: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tataria, H.; Gross, O.; Bae, C.

Global automakers are accelerating the development of fuel efficient vehicles, as a part of meeting regional regulatory CO2 emissions requirements. The micro hybrid vehicles with auto start-stop functionality are considered economical solutions for the stringent European regulations. Flooded lead acid batteries were initially considered the most economical solution for idle-stop systems. However, the dynamic charge acceptance (DCA) at lower state-of-charge (SOC) was limiting the life of the batteries. While improved lead-acid batteries with AGM and VRLA features have improved battery longevity, they do not last the life of the vehicle. The United States Advanced Battery Consortium (or USABC, a consortiummore » of GM, Ford, and Chrysler) analyzed energy storage needs for a micro hybrid automobile with start-stop capability, and with a single power source. USABC has analyzed the start-stop behaviors of many drivers and has developed the requirements for the start-stop batteries (Table 3). The testing procedures to validate the performance and longevity were standardized and published. The guideline for the cost estimates calculations have also been provided, in order to determine the value of the newly developed modules. The analysis effort resulted in a set of requirements which will help the battery manufacturers to develop a module to meet the automotive Original Equipment Manufacturers (OEM) micro hybrid vehicle requirements. Battery developers were invited to submit development proposals and two proposals were selected for 50% cost share with USABC/DOE.« less

U. S. light duty vehicle fleet emissions performance and the emissions impact of technology changes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabourin, M.; Platte, L

1988-01-01

This paper determines the level of improvement in Federal Test Procedure (FTP) exhaust emissions realized by typical in-use vehicles over the last twenty years as emission standards have become increasingly stringent. Furthermore, this paper explores the likelihood that in-use emission performance improvements will continue now that emission standards have stabilized.

The Effect of Emissions Trading And Carbon Sequestration on The Cost Of CO2 Emissions Mitigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahasenan, Natesan; Scott, Michael J.; Smith, Steven J.

2002-08-05

The deployment of carbon capture and sequestration (CC&S) technologies is greatly affected by the marginal cost of controlling carbon emissions (also the value of carbon, when emissions permits are traded). Emissions limits that are more stringent in the near term imply higher near-term carbon values and therefore encourage the local development and deployment of CC&S technologies. In addition, trade in emissions obligations lowers the cost of meeting any regional or global emissions limit and so affects the rate of penetration of CC&S technologies. We examine the effects of the availability of sequestration opportunities and emissions trading (either within select regionsmore » or globally) on the cost of emissions mitigation and compliance with different emissions reduction targets for the IPCC SRES scenarios. For each base scenario and emissions target, we examine the issues outlined above and present quantitative estimates for the impacts of trade and the availability of sequestration opportunities in meeting emissions limitation obligations.« less

Lessons Learned in the Design and Use of IP1 / IP2 Flexible Packaging - 13621

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanchez, Mike; Reeves, Wendall; Smart, Bill

2013-07-01

For many years in the USA, Low Level Radioactive Waste (LLW), contaminated soils and construction debris, have been transported, interim stored, and disposed of, using IP1 / IP2 metal containers. The performance of these containers has been more than adequate, with few safety occurrences. The containers are used under the regulatory oversight of the US Department of Transportation (DOT), 49 Code of Federal Regulations (CFR). In the late 90's the introduction of flexible packaging for the transport, storage, and disposal of low level contaminated soils and construction debris was introduced. The development of flexible packaging came out of a needmore » for a more cost effective package, for the large volumes of waste generated by the decommissioning of many of the US Department of Energy (DOE) legacy sites across the US. Flexible packaging had to be designed to handle a wide array of waste streams, including soil, gravel, construction debris, and fine particulate dust migration. The design also had to meet all of the IP1 requirements under 49CFR 173.410, and be robust enough to pass the IP2 testing 49 CFR 173.465 required for many LLW shipments. Tens of thousands of flexible packages have been safely deployed and used across the US nuclear industry as well as for hazardous non-radioactive applications, with no recorded release of radioactive materials. To ensure that flexible packages are designed properly, the manufacturer must use lessons learned over the years, and the tests performed to provide evidence that these packages are suitable for transporting low level radioactive wastes. The design and testing of flexible packaging for LLW, VLLW and other hazardous waste streams must be as strict and stringent as the design and testing of metal containers. The design should take into consideration the materials being loaded into the package, and should incorporate the right materials, and manufacturing methods, to provide a quality, safe product. Flexible packaging can be shown to meet the criteria for safe and fit for purpose packaging, by meeting the US DOT regulations, and the IAEA Standards for IP-1 and IP-2 including leak tightness. (authors)« less

Nonlinear control systems - A brief overview of historical and recent advances

NASA Astrophysics Data System (ADS)

Iqbal, Jamshed; Ullah, Mukhtar; Khan, Said Ghani; Khelifa, Baizid; Ćuković, Saša

2017-12-01

Last five decades witnessed remarkable developments in linear control systems and thus problems in this subject has been largely resolved. The scope of the present paper is beyond linear solutions. Modern technology demands sophisticated control laws to meet stringent design specifications thus highlighting the increasingly conspicuous position of nonlinear control systems, which is the topic of this paper. Historical role of analytical concepts in analysis and design of nonlinear control systems is briefly outlined. Recent advancements in these systems from applications perspective are examined with critical comments on associated challenges. It is anticipated that wider dissemination of this comprehensive review will stimulate more collaborations among the research community and contribute to further developments.

Design, qualification, manufacturing and integration of IXV Ablative Thermal Protection System

NASA Astrophysics Data System (ADS)

Cioeta, Mario; Di Vita, Gandolfo; Signorelli Maria, Teresa; Bianco, Gianluca; Cutroni, Maurizio; Damiani, Francesco; Ferretti, Viviana; Rotondo, Adriano

2016-07-01

In the present paper, all the activities carried out by Avio S.p.A in order to define, qualify, manufacture and integrate the IXV Ablative TPS will be presented. In particular the extensive numerical simulation in both small and full scale testing activities will be overviewed. Wide-ranging testing activity has been carried out in order to verify, confirm and correlate the numerical models used for TPS sizing. Tests ranged from classical thermo-mechanical characterization traction specimens to tests in plasma wind tunnels on dedicated prototypes. Finally manufacturing and integration activities will be described emphasizing technological aspects solved in order to meet the stringent requirements in terms of shape accuracy and integration tolerances.

Design and testing of the Space Station Freedom Propellant Tank Assembly

NASA Technical Reports Server (NTRS)

Dudley, D. D.; Thonet, T. A.; Goforth, A. M.

1992-01-01

Propellant storage and management functions for the Propulsion Module of the U.S. Space Station Freedom are provided by the Propellant Tank Assembly (PTA). The PTA consists of a surface-tension type propellant acquisition device contained within a welded titanium pressure vessel. The PTA design concept was selected with high reliability and low program risk as primary goals in order to meet stringent NASA structural, expulsion, fracture control and reliability requirements. The PTA design makes use of Shuttle Orbital Maneuvering System and Peacekeeper Propellant Storage Assembly design and analysis techniques. This paper summarizes the PTA design solution and discusses the underlying detailed analyses. In addition, design verification and qualification test activities are discussed.

Evaluation of insulation materials and composites for use in a nuclear radiation environment, phase 1

NASA Technical Reports Server (NTRS)

Greenhow, W. A.; Lewis, J. H.

1972-01-01

This study has been carried out to evaluate flight-qualified Saturn 5 materials, components, and systems for use, with or without modification, in the radiation environment of the nuclear flight system. The results reported herein are primarily intended to aid designers in their evaluation and selection of off-the-shelf equipments which may meet the stringent requirements and specifications associated with application on a reusable nuclear powered space system, i.e., the reusable nuclear shuttle. One of the factors which must be evaluated in the design of the RNS is the effects of radiation on materials; and it is toward this aspect of the overall effort that this analysis has been directed.

High Resolution Imaging from the Stratosphere: Atmospheric Seeing and Tether Dynamics

NASA Technical Reports Server (NTRS)

Ford, Holland

2003-01-01

A balloon-borne telescope that is capable of imaging planets orbiting nearby stars requires that the flatness and tilt of the wavefront of the light entering that telescope meet certain stringent conditions. The atmosphere through which the light propagates distorts the wavefront due to turbulence in the atmosphere and due to the disturbances caused by the balloon itself The magnitude of these effects may be estimated, but no direct measurements have been made at the level of precision necessary for designing a telescope as demanding as we envision. Therefore, under this grant we carried out a study of techniques that could be used to make an in situ measurement of the distortion of the optical wavefront.

Space Suit Spins

NASA Technical Reports Server (NTRS)

2005-01-01

Space is a hostile environment where astronauts combat extreme temperatures, dangerous radiation, and a near-breathless vacuum. Life support in these unforgiving circumstances is crucial and complex, and failure is not an option for the devices meant to keep astronauts safe in an environment that presents constant opposition. A space suit must meet stringent requirements for life support. The suit has to be made of durable material to withstand the impact of space debris and protect against radiation. It must provide essential oxygen, pressure, heating, and cooling while retaining mobility and dexterity. It is not a simple article of clothing but rather a complex modern armor that the space explorers must don if they are to continue exploring the heavens

Review of measurement instruments in clinical and research ethics, 1999–2003

PubMed Central

Redman, B K

2006-01-01

Every field of practice has the responsibility to evaluate its outcomes and to test its theories. Evidence of the underdevelopment of measurement instruments in bioethics suggests that attending to strengthening existing instruments and developing new ones will facilitate the interpretation of accumulating bodies of research as well as the making of clinical judgements. A review of 65 instruments reported in the published literature showed 10 with even a minimal level of psychometric data. Two newly developed instruments provide examples of the full use of psychometric and ethical theory. Bioethicists use a wide range of methods for knowledge development and verification; each method should meet stringent standards of quality. PMID:16507659

The urgency of the development of CO2 capture from ambient air

PubMed Central

Lackner, Klaus S.; Brennan, Sarah; Matter, Jürg M.; Park, A.-H. Alissa; Wright, Allen; van der Zwaan, Bob

2012-01-01

CO2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO2 directly from the atmosphere. Air capture of CO2 could act as insurance against CO2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes. PMID:22843674

Evaluating diffraction based overlay metrology for double patterning technologies

NASA Astrophysics Data System (ADS)

Saravanan, Chandra Saru; Liu, Yongdong; Dasari, Prasad; Kritsun, Oleg; Volkman, Catherine; Acheta, Alden; La Fontaine, Bruno

2008-03-01

Demanding sub-45 nm node lithographic methodologies such as double patterning (DPT) pose significant challenges for overlay metrology. In this paper, we investigate scatterometry methods as an alternative approach to meet these stringent new metrology requirements. We used a spectroscopic diffraction-based overlay (DBO) measurement technique in which registration errors are extracted from specially designed diffraction targets for double patterning. The results of overlay measurements are compared to traditional bar-in-bar targets. A comparison between DBO measurements and CD-SEM measurements is done to show the correlation between the two approaches. We discuss the total measurement uncertainty (TMU) requirements for sub-45 nm nodes and compare TMU from the different overlay approaches.

Solid-state chemistry and particle engineering with supercritical fluids in pharmaceutics.

PubMed

Pasquali, Irene; Bettini, Ruggero; Giordano, Ferdinando

2006-03-01

The present commentary aims to review the modern and innovative strategies in particle engineering by the supercritical fluid technologies and it is principally concerned with the aspects of solid-state chemistry. Supercritical fluids based processes for particle production have been proved suitable for controlling solid-state, morphology and particle size of pharmaceuticals, in some cases on an industrial scale. Supercritical fluids should be considered in a prominent position in the development processes of drug products for the 21st century. In this respect, this innovative technology will help in meeting the more and more stringent requirements of regulatory authorities in terms of solid-state characterisation and purity, and environmental acceptability.

Toward a neurologic model of competency: Cognitive predictors of capacity to consent in Alzheimer's disease using three different legal standards.

PubMed

Marson, D C; Chatterjee, A; Ingram, K K; Harrell, L E

1996-03-01

To identify cognitive predictors of competency performance and status in Alzheimer's disease (AD) using three differentially stringent legal standards for capacity to consent. Univariate and multivariate analyses of independent neuropsychological test measures with three dependent measures of competency to consent to treatment. University medical center. 15 normal older controls and 29 patients with probably AD (15 mild and 14 moderate). Subjects were administered a batter of neuropsychological measures theoretically linked to competency function, as well as two clinical vignettes testing capacity to consent to medical treatment under five legal standards (LSs). The present study focused on three differentially stringent LSs: the capacity simply to "evidence a treatment of choice" (LS1), which is a minimal standard; the capacity to "appreciate the consequences" of a treatment of choice (LS3), a moderately stringent standard; and the capacity to "understand the treatment situation and choices" (LS5), the most stringent standard. Control subject and AD patient neuropsychological test scores were correlated with scores on the three LSs. The resulting univariate correlates were than analyzed using stepwise regression and discriminant function to identify key multivariate predictors of competency performance and status under each LS. No neuropsychological measures predicted control group performance on the LSs. For the AD group, a measure of simple auditory comprehension predicted LS1 performance (r(2)=0.44, p < 0.0001), a word fluency measure predicted LS3 performance (r(2)=0.58, p < 0.0001), and measures of conceptualization and confrontation naming together predicted LS5 performance (r(2)=0.81, p < 0.0001). Under discriminant function analysis, confrontation naming was the best single predictor of LS1 competency status for all subjects, correctly classifying 96% of cases (42/44). Measures of visumotor tracking and confrontation naming were the best single predictors, respectively, of competency status under LS3 (91% [39/43]) and LS5 (98% [43/44]). Multiple cognitive functions are associated with loss of competency in AD. Deficits in conceptualization, semantic memory, and probably verbal recall are associated with the declining capacity of mild AD patients to understand a treatment situation and choices (LS5); executive dysfunction with the declining capacity of mild to moderate AD patients to identify the consequences of treatment choice (LS3); and receptive aphasia and severe dysnomia with the declining capacity of advanced AD patients to evidence a simple treatment choice (LS1). The results offer insight into the relationship between different legal thresholds of competency and the progressive cognitive changes characteristic of AD, and represent an initial step toward a neurologic model of competency.

Stringent homology-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions.

PubMed

Zhou, Hufeng; Gao, Shangzhi; Nguyen, Nam Ninh; Fan, Mengyuan; Jin, Jingjing; Liu, Bing; Zhao, Liang; Xiong, Geng; Tan, Min; Li, Shijun; Wong, Limsoon

2014-04-08

H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are essential for understanding the infection mechanism of the formidable pathogen M. tuberculosis H37Rv. Computational prediction is an important strategy to fill the gap in experimental H. sapiens-M. tuberculosis H37Rv PPI data. Homology-based prediction is frequently used in predicting both intra-species and inter-species PPIs. However, some limitations are not properly resolved in several published works that predict eukaryote-prokaryote inter-species PPIs using intra-species template PPIs. We develop a stringent homology-based prediction approach by taking into account (i) differences between eukaryotic and prokaryotic proteins and (ii) differences between inter-species and intra-species PPI interfaces. We compare our stringent homology-based approach to a conventional homology-based approach for predicting host-pathogen PPIs, based on cellular compartment distribution analysis, disease gene list enrichment analysis, pathway enrichment analysis and functional category enrichment analysis. These analyses support the validity of our prediction result, and clearly show that our approach has better performance in predicting H. sapiens-M. tuberculosis H37Rv PPIs. Using our stringent homology-based approach, we have predicted a set of highly plausible H. sapiens-M. tuberculosis H37Rv PPIs which might be useful for many of related studies. Based on our analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent homology-based approach, we have discovered several interesting properties which are reported here for the first time. We find that both host proteins and pathogen proteins involved in the host-pathogen PPIs tend to be hubs in their own intra-species PPI network. Also, both host and pathogen proteins involved in host-pathogen PPIs tend to have longer primary sequence, tend to have more domains, tend to be more hydrophilic, etc. And the protein domains from both host and pathogen proteins involved in host-pathogen PPIs tend to have lower charge, and tend to be more hydrophilic. Our stringent homology-based prediction approach provides a better strategy in predicting PPIs between eukaryotic hosts and prokaryotic pathogens than a conventional homology-based approach. The properties we have observed from the predicted H. sapiens-M. tuberculosis H37Rv PPI network are useful for understanding inter-species host-pathogen PPI networks and provide novel insights for host-pathogen interaction studies.

Genotypic variability enhances the reproducibility of an ecological study.

PubMed

Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M; Blouin, Manuel; Scheu, Stefan; Freschet, Grégoire T; Rose, Laura; Barot, Sebastien; Cesarz, Simone; Eisenhauer, Nico; Girin, Thomas; Assandri, Davide; Bonkowski, Michael; Buchmann, Nina; Butenschoen, Olaf; Devidal, Sebastien; Gleixner, Gerd; Gessler, Arthur; Gigon, Agnès; Greiner, Anna; Grignani, Carlo; Hansart, Amandine; Kayler, Zachary; Lange, Markus; Lata, Jean-Christophe; Le Galliard, Jean-François; Lukac, Martin; Mannerheim, Neringa; Müller, Marina E H; Pando, Anne; Rotter, Paula; Scherer-Lorenzen, Michael; Seyhun, Rahme; Urban-Mead, Katherine; Weigelt, Alexandra; Zavattaro, Laura; Roy, Jacques

2018-02-01

Many scientific disciplines are currently experiencing a 'reproducibility crisis' because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduce reproducibility by amplifying the impacts of laboratory-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that a deliberate introduction of controlled systematic variability (CSV) in experimental designs may lead to increased reproducibility. To test this hypothesis, we had 14 European laboratories run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to 18% lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility was generally lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the 'reproducibility crisis', deliberately including genetic variability may be a simple solution for increasing the reproducibility of ecological studies performed under stringently controlled environmental conditions.

Regional ITS architecture guidance : developing, using, and maintaining an ITS architecture for your region

DOT National Transportation Integrated Search

1998-08-01

The purpose of this TechBrief is to discuss one of the Long Term Pavement Performance (LTPP) program's stringent data requirements - site-specific measurements for estimating pavement loadings - and to illustrate the effects of traffic loading data e...

Dimensional stability performance of a CFRP sandwich optical bench for microsatellite payload

NASA Astrophysics Data System (ADS)

Desnoyers, N.; Goyette, P.; Leduc, B.; Boucher, M.-A.

2017-09-01

Microsatellite market requires high performance while minimizing mass, volume and cost. Telescopes are specifically targeted by these trade-offs. One of these is to use the optomechanical structure of the telescope to mount electronic devices that may dissipate heat. However, such approach may be problematic in terms of distortions due to the presence of high thermal gradients throughout the telescope structure. To prevent thermal distortions, Carbon Fiber Reinforced Polymer (CFRP) technology can be used for the optomechanical telescope material structure. CFRP is typically about 100 times less sensitive to thermal gradients and its coefficient of thermal expansion (CTE) is about 200 to 600 times lower than standard aluminum alloys according to inhouse measurements. Unfortunately, designing with CFRP material is not as straightforward as with metallic materials. There are many parameters to consider in order to reach the desired dimensional stability under thermal, moisture and vibration exposures. Designing optomechanical structures using CFRP involves many challenges such as interfacing with optics and sometimes dealing with high CTE mounting interface structures like aluminum spacecraft buses. INO has designed a CFRP sandwich telescope structure to demonstrate the achievable performances of such technology. Critical parameters have been optimized to maximize the dimensional stability while meeting the stringent environmental requirements that microsatellite payloads have to comply with. The telescope structure has been tested in vacuum from -40°C to +50°C and has shown a good fit with finite element analysis predictions.

A New Generation of Real-Time Systems in the JET Tokamak

NASA Astrophysics Data System (ADS)

Alves, Diogo; Neto, Andre C.; Valcarcel, Daniel F.; Felton, Robert; Lopez, Juan M.; Barbalace, Antonio; Boncagni, Luca; Card, Peter; De Tommasi, Gianmaria; Goodyear, Alex; Jachmich, Stefan; Lomas, Peter J.; Maviglia, Francesco; McCullen, Paul; Murari, Andrea; Rainford, Mark; Reux, Cedric; Rimini, Fernanda; Sartori, Filippo; Stephen, Adam V.; Vega, Jesus; Vitelli, Riccardo; Zabeo, Luca; Zastrow, Klaus-Dieter

2014-04-01

Recently, a new recipe for developing and deploying real-time systems has become increasingly adopted in the JET tokamak. Powered by the advent of x86 multi-core technology and the reliability of JET's well established Real-Time Data Network (RTDN) to handle all real-time I/O, an official Linux vanilla kernel has been demonstrated to be able to provide real-time performance to user-space applications that are required to meet stringent timing constraints. In particular, a careful rearrangement of the Interrupt ReQuests' (IRQs) affinities together with the kernel's CPU isolation mechanism allows one to obtain either soft or hard real-time behavior depending on the synchronization mechanism adopted. Finally, the Multithreaded Application Real-Time executor (MARTe) framework is used for building applications particularly optimised for exploring multi-core architectures. In the past year, four new systems based on this philosophy have been installed and are now part of JET's routine operation. The focus of the present work is on the configuration aspects that enable these new systems' real-time capability. Details are given about the common real-time configuration of these systems, followed by a brief description of each system together with results regarding their real-time performance. A cycle time jitter analysis of a user-space MARTe based application synchronizing over a network is also presented. The goal is to compare its deterministic performance while running on a vanilla and on a Messaging Real time Grid (MRG) Linux kernel.

Optical Breath Gas Sensor for Extravehicular Activity Application

NASA Technical Reports Server (NTRS)

Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S> ; Chullen, Cinda; Falconi, Eric A.

2012-01-01

The function of the infrared gas transducer used during extravehicular activity (EVA) in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation Portable Life Support System (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode (LD) spectrometer based on wavelength modulation spectroscopy (WMS) is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen (O2) channel using a vertical cavity surface emitting laser (VCSEL). Both prototypes are controlled digitally with a field-programmable gate array (FPGA)/microcontroller architecture. Based on the results of the initial instrument development, further prototype development and testing of instruments leveraging the lessons learned were desired. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU. .

Conformal Pad-Printing Electrically Conductive Composites onto Thermoplastic Hemispheres: Toward Sustainable Fabrication of 3-Cents Volumetric Electrically Small Antennas.

PubMed

Wu, Haoyi; Chiang, Sum Wai; Yang, Cheng; Lin, Ziyin; Liu, Jingping; Moon, Kyoung-Sik; Kang, Feiyu; Li, Bo; Wong, Ching Ping

2015-01-01

Electrically small antennas (ESAs) are becoming one of the key components in the compact wireless devices for telecommunications, defence, and aerospace systems, especially for the spherical one whose geometric layout is more closely approaching Chu's limit, thus yielding significant bandwidth improvements relative to the linear and planar counterparts. Yet broad applications of the volumetric ESAs are still hindered since the low cost fabrication has remained a tremendous challenge. Here we report a state-of-the-art technology to transfer electrically conductive composites (ECCs) from a planar mould to a volumetric thermoplastic substrate by using pad-printing technology without pattern distortion, benefit from the excellent properties of the ECCs as well as the printing-calibration method that we developed. The antenna samples prepared in this way meet the stringent requirement of an ESA (ka is as low as 0.32 and the antenna efficiency is as high as 57%), suggesting that volumetric electronic components i.e. the antennas can be produced in such a simple, green, and cost-effective way. This work can be of interest for the development of studies on green and high performance wireless communication devices.

Trajectory and navigation system design for robotic and piloted missions to Mars

NASA Technical Reports Server (NTRS)

Thurman, S. W.; Matousek, S. E.

1991-01-01

Future Mars exploration missions, both robotic and piloted, may utilize Earth to Mars transfer trajectories that are significantly different from one another, depending upon the type of mission being flown and the time period during which the flight takes place. The use of new or emerging technologies for future missions to Mars, such as aerobraking and nuclear rocket propulsion, may yield navigation requirements that are much more stringent than those of past robotic missions, and are very difficult to meet for some trajectories. This article explores the interdependencies between the properties of direct Earth to Mars trajectories and the Mars approach navigation accuracy that can be achieved using different radio metric data types, such as ranging measurements between an approaching spacecraft and Mars orbiting relay satellites, or Earth based measurements such as coherent Doppler and very long baseline interferometry. The trajectory characteristics affecting navigation performance are identified, and the variations in accuracy that might be experienced over the range of different Mars approach trajectories are discussed. The results predict that three sigma periapsis altitude navigation uncertainties of 2 to 10 km can be achieved when a Mars orbiting satellite is used as a navigation aid.

An assessment of the economic status of the antifriction bearing industry

NASA Astrophysics Data System (ADS)

Peterson, Donna J.; Kelley, Gerald T.; Myers, Myron G.

1991-10-01

Military equipment with moving parts requires antifriction bearings. Superprecision bearings, which are manufactured with closer tolerances under more stringent conditions, are often needed to meet high-performance characteristics such as silencing in submarines. A steady increase in imports of antifriction bearings coupled with reduced prices and profitability in the domestic industry led domestic manufacturers to seek legislative and regulatory relief from foreign competition. Since 1987, the Government has provided two types of relief to the industry. First, after a Department of Commerce investigation established that foreign producers were selling products in the U.S. market at prices below those they charged in their home markets, the Government imposed antidumping duties on several types of bearings from 12 countries. Second, the DoD restricted the purchase of antifriction bearing for use in defense end items to those of domestic manufacture. Although that restriction is due to expire on 30 Sep. 1991, the DoD may renew it for an additional 2 years if conditions warrant. This study assesses the current economic health of the U.S. antifriction bearing industry, analyzes the relative impact of the two forms of relief provided to the industry, and discusses the advantages and disadvantages of DoD's policy options.

Fault tolerant computer control for a Maglev transportation system

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan H.; Nagle, Gail A.; Anagnostopoulos, George

1994-01-01

Magnetically levitated (Maglev) vehicles operating on dedicated guideways at speeds of 500 km/hr are an emerging transportation alternative to short-haul air and high-speed rail. They have the potential to offer a service significantly more dependable than air and with less operating cost than both air and high-speed rail. Maglev transportation derives these benefits by using magnetic forces to suspend a vehicle 8 to 200 mm above the guideway. Magnetic forces are also used for propulsion and guidance. The combination of high speed, short headways, stringent ride quality requirements, and a distributed offboard propulsion system necessitates high levels of automation for the Maglev control and operation. Very high levels of safety and availability will be required for the Maglev control system. This paper describes the mission scenario, functional requirements, and dependability and performance requirements of the Maglev command, control, and communications system. A distributed hierarchical architecture consisting of vehicle on-board computers, wayside zone computers, a central computer facility, and communication links between these entities was synthesized to meet the functional and dependability requirements on the maglev. Two variations of the basic architecture are described: the Smart Vehicle Architecture (SVA) and the Zone Control Architecture (ZCA). Preliminary dependability modeling results are also presented.

Ultra Low Outgassing silicone performance in a simulated space ionizing radiation environment

NASA Astrophysics Data System (ADS)

Velderrain, M.; Malave, V.; Taylor, E. W.

2010-09-01

The improvement of silicone-based materials used in space and aerospace environments has garnered much attention for several decades. Most recently, an Ultra Low Outgassing™ silicone incorporating innovative reinforcing and functional fillers has shown that silicone elastomers with unique and specific properties can be developed to meet applications requiring stringent outgassing requirements. This paper will report on the next crucial step in qualifying these materials for spacecraft applications requiring chemical and physical stability in the presence of ionizing radiation. As a first step in this process, selected materials were irradiated with Co-60 gamma-rays to simulate the total dose received in near- Earth orbits. The paper will present pre-and post-irradiation response data of Ultra Low Outgassing silicone samples exposed under ambient air environment coupled with measurements of collected volatile condensable material (CVCM) and total mass loss (TML) per the standard conditions in ASTM E 595. The data will show an insignificant effect on the CVCMs and TMLs after exposure to various dosages of gamma radiation. This data may favorably impact new applications for these silicone materials for use as an improved sealant for space solar cell systems, space structures, satellite systems and aerospace systems.

Adapting the Reconfigurable SpaceCube Processing System for Multiple Mission Applications

NASA Technical Reports Server (NTRS)

Petrick, Dave

2014-01-01

This paper will detail the use of SpaceCube in multiple space flight applications including the Hubble Space Telescope Servicing Mission 4 (HST-SM4), an International Space Station (ISS) radiation test bed experiment, and the main avionics subsystem for two separate ISS attached payloads. Each mission has had varying degrees of data processing complexities, performance requirements, and external interfaces. We will show the methodology used to minimize the changes required to the physical hardware, FPGA designs, embedded software interfaces, and testing.This paper will summarize significant results as they apply to each mission application. In the HST-SM4 application we utilized the FPGA resources to accelerate portions of the image processing algorithms more than 25 times faster than a standard space processor in order to meet computational speed requirements. For the ISS radiation on-orbit demonstration, the main goal is to show that we can rely on the commercial FPGAs and processors in a space environment. We describe our FPGA and processor radiation mitigation strategies that have resulted in our eight PowerPCs being available and error free for more than 99.99 of the time over the period of four years. This positive data and proven reliability of the SpaceCube on ISS resulted in the Department of Defense (DoD) selecting SpaceCube, which is replacing an older and slower computer currently used on ISS, as the main avionics for two upcoming ISS experiment campaigns. This paper will show how we quickly reconfigured the SpaceCube system to meet the more stringent reliability requirements

Addressing Thermal Model Run Time Concerns of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA)

NASA Technical Reports Server (NTRS)

Peabody, Hume; Guerrero, Sergio; Hawk, John; Rodriguez, Juan; McDonald, Carson; Jackson, Cliff

2016-01-01

The Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) utilizes an existing 2.4 m diameter Hubble sized telescope donated from elsewhere in the federal government for near-infrared sky surveys and Exoplanet searches to answer crucial questions about the universe and dark energy. The WFIRST design continues to increase in maturity, detail, and complexity with each design cycle leading to a Mission Concept Review and entrance to the Mission Formulation Phase. Each cycle has required a Structural-Thermal-Optical-Performance (STOP) analysis to ensure the design can meet the stringent pointing and stability requirements. As such, the models have also grown in size and complexity leading to increased model run time. This paper addresses efforts to reduce the run time while still maintaining sufficient accuracy for STOP analyses. A technique was developed to identify slews between observing orientations that were sufficiently different to warrant recalculation of the environmental fluxes to reduce the total number of radiation calculation points. The inclusion of a cryocooler fluid loop in the model also forced smaller time-steps than desired, which greatly increases the overall run time. The analysis of this fluid model required mitigation to drive the run time down by solving portions of the model at different time scales. Lastly, investigations were made into the impact of the removal of small radiation couplings on run time and accuracy. Use of these techniques allowed the models to produce meaningful results within reasonable run times to meet project schedule deadlines.

Controlling Precision Stepper Motors in Flight Using (Almost) No Parts

NASA Technical Reports Server (NTRS)

Randall, David

2010-01-01

This concept allows control of high-performance stepper motors with minimal parts count and minimal flight software complexity. Although it uses a small number of common flight-qualified parts and simple control algorithms, it is capable enough to meet demanding system requirements. Its programmable nature makes it trivial to implement changes to control algorithms both during integration & test and in flight. Enhancements such as microstepping, half stepping, back-emf compensation, and jitter reduction can be tailored to the requirements of a large variety of stepper motor based applications including filter wheels, focus mechanisms, antenna tracking subsystems, pointing and mobility. The hardware design (using an H-bridge motor controller IC) was adapted from JPL's MER mission, still operating on Mars. This concept has been fully developed and incorporated into the MCS instrument on MRO, currently operating in Mars orbit. It has been incorporated into the filter wheel mechanism and linear stage (focus) mechanism for the AMT instrument. On MCS/MRO, two of these circuits control the elevation and azimuth of the MCS telescope/radiometer assembly, allowing the instrument to continuously monitor the limb of the Martian atmosphere. Implementation on MCS/MRO resulted in a 4:1 reduction in the volume and mass required for the motor driver electronics (100:25 square inches of PCB space), producing a very compact instrument. In fact, all of the electronics for the MCS instrument are packaged within the movable instrument structure. It also saved approximately 3 Watts of power. Most importantly, the design enabled MCS to meet very its stringent maximum allowable torque disturbance requirements.

Orphan Toxin OrtT (YdcX) of Escherichia coli Reduces Growth during the Stringent Response

DTIC Science & Technology

2015-01-29

antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting tetrahydrofolate synthesis...in the presence of both antimicrobials trimethoprim and sulfamethoxazole; these antimicrobials induce the stringent response by inhibiting...level [20]. Toxins 2015, 7 301 Despite these difficulties in determining physiological roles, TA systems are clearly phage inhibition systems

An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

NASA Astrophysics Data System (ADS)

Robey, H. F.; Munro, D. H.; Spears, B. K.; Marinak, M. M.; Jones, O. S.; Patel, M. V.; Haan, S. W.; Salmonson, J. D.; Landen, O. L.; Boehly, T. R.; Nikroo, A.

2008-05-01

Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of <= +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

Real time testing of intelligent relays for synchronous distributed generation islanding detection

NASA Astrophysics Data System (ADS)

Zhuang, Davy

As electric power systems continue to grow to meet ever-increasing energy demand, their security, reliability, and sustainability requirements also become more stringent. The deployment of distributed energy resources (DER), including generation and storage, in conventional passive distribution feeders, gives rise to integration problems involving protection and unintentional islanding. Distributed generators need to be islanded for safety reasons when disconnected or isolated from the main feeder as distributed generator islanding may create hazards to utility and third-party personnel, and possibly damage the distribution system infrastructure, including the distributed generators. This thesis compares several key performance indicators of a newly developed intelligent islanding detection relay, against islanding detection devices currently used by the industry. The intelligent relay employs multivariable analysis and data mining methods to arrive at decision trees that contain both the protection handles and the settings. A test methodology is developed to assess the performance of these intelligent relays on a real time simulation environment using a generic model based on a real-life distribution feeder. The methodology demonstrates the applicability and potential advantages of the intelligent relay, by running a large number of tests, reflecting a multitude of system operating conditions. The testing indicates that the intelligent relay often outperforms frequency, voltage and rate of change of frequency relays currently used for islanding detection, while respecting the islanding detection time constraints imposed by standing distributed generator interconnection guidelines.

Initial Closed Operation of the CELSS Test Facility Engineering Development Unit

NASA Technical Reports Server (NTRS)

Kliss, Mark

1995-01-01

As part of the NASA Controlled Ecological Life Support System (CELSS) Program, a CELSS Test Facility (CTF) is being planned for installation on the Space Station. The CTF will be used to provide data on the productivity and efficiency of a variety of CELSS higher plant crops grown sequentially from seed to harvest in the microgravity environment of the Space Station. Stringent environmental control will be maintained while fundamental crop productivity issues, such as carbon dioxide uptake and oxygen production rates, water transpiration rates, and biomass accumulation rates are obtained for comparison with ground-based data. In order to obtain an early realistic determination of the subsystem and system requirements necessary to provide the appropriate environmental conditions specified for CTF crop productivity experiments, an Engineering Development Unit (EDU) has been constructed and is undergoing initial operational testing at NASA Ames Research Center. The EDU is a ground-based testbed which will be used to characterize the integrated performance of major subsystem technologies, to evaluate hardware candidates and control strategies required for the CTF, and to further define the ability to meet CTF requirements within present Space Station constraints. This paper describes the initial closed operational testing of the EDU. Measured performance data are compared with the specified functional requirements and results from initial closed testing are presented. Plans for future science and technology testing are discussed.

Mission Concept for the Single Aperture Far-Infrared (SAFIR) Observatory

NASA Technical Reports Server (NTRS)

Benford, Dominic J.; Amato, Michael J.; Mather, John C.; Moseley, S. Harvey, Jr.

2004-01-01

We have developed a preliminary but comprehensive mission concept for SAFIR, as a 10 m-class far-infrared and submillimeter observatory that would begin development later in this decade to meet the needs outlined above. Its operating temperature (< or = 4K) and instrument complement would be optimized to reach the natural sky confusion limit in the far-infrared with diffraction-limited performance down to at least the atmospheric cutoff, lambda > or approx. 40 microns. This would provide a point source sensitivity improvement of several orders of magnitude over that of the Spitzer Space Telescope (previously SIRTF) or the Herschel Space Observatory. Additionally, it would have an angular resolution 12 times finer than that of Spitzer and three times finer than Herschel. This sensitivity and angular resolution are necessary to perform imaging and spectroscopic studies of individual galaxies in the early universe. We have considered many aspects of the SAFIR mission, including the telescope technology (optical design, materials, and packaging), detector needs and technologies, cooling method and required technology developments, attitude and pointing, power systems, launch vehicle, and mission operations. The most challenging requirements for this mission are operating temperature and aperture size of the telescope, and the development of detector arrays. SAFIR can take advantage of much of the technology under development for JWST, but with much less stringent requirements on optical accuracy.

77 FR 51024 - Information Collection Being Reviewed by the Federal Communications Commission

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-23

... interference environment would allow the applicant to use a less stringent Category B antenna (although the applicant could choose to sue a higher performance Category A antenna); The applicant specifically acknowledges its duty to upgrade to a Category A antenna and come into compliance with the applicable...

Liberal Grading Improves Evaluations But Not Performance.

ERIC Educational Resources Information Center

Vasta, Ross; Sarmiento, Robert F.

Two grading distributions--a liberal and a more stringent curve--were compared between two sections of an undergraduate psychology course. The two classes were team taught and treated as similarly as possible. Four unit exams and an optional final were administered, with one section consistently receiving a more lenient grade distribution. No…

Revamping Teacher Evaluation

ERIC Educational Resources Information Center

Zatynski, Mandy

2012-01-01

In the past two years, as concerns over teacher quality have swelled, teacher evaluation has emerged as a crucial tool for principals and other administrators to improve instructor performance. More states are seeking federal waivers to the stringent benchmarks of No Child Left Behind; others are vying for Race to the Top funds. Both require…

Oral bioaccessibility testing and read-across hazard assessment of nickel compounds.

PubMed

Henderson, Rayetta G; Cappellini, Danielle; Seilkop, Steven K; Bates, Hudson K; Oller, Adriana R

2012-06-01

In vitro metal ion bioaccessibility, as a measure of bioavailability, can be used to read-across toxicity information from data-rich, source substances to data-poor, target substances. To meet the data requirements for oral systemic toxicity endpoints under the REACH Regulation in Europe, 12 nickel substances underwent bioaccessibility testing in stomach and intestinal fluids. A read-across paradigm was developed based on the correlation between gastric bioaccessibility and in vivo acute oral toxicity. The oral LD₅₀ values were well predicted by nickel release (R² = 0.91). Samples releasing <48% available nickel (mgNi released/mg available Ni × 100) are predicted to have an LD₅₀ > 2000 mg/kg; while samples releasing > 76% available nickel are expected to have an LD₅₀ between 300 and 2000 mg/kg. The hazard classifications (European Regulation on Classification, Labelling and Packaging of Chemical Substances and Mixtures) for all oral systemic endpoints were evaluated based on read-across from three source nickel compounds (sulfate, subsulfide, oxide). Samples releasing < 48% available nickel were read-across from nickel oxides and subsulfide. Samples releasing > 76% Ni were read-across from nickel sulfate. This assessment suggests that nickel chloride and dihydroxide should be less stringently classified and nickel sulfamate should receive a more stringent classification for oral systemic endpoints than currently assigned. Copyright © 2012 Elsevier Inc. All rights reserved.

The Bendability of Ultra High strength Steels

NASA Astrophysics Data System (ADS)

Hazra, S. K.; Efthymiadis, P.; Alamoudi, A.; Kumar, R. L. V.; Shollock, B.; Dashwood, R.

2016-08-01

Automotive manufacturers have been reducing the weight of their vehicles to meet increasingly stringent environmental legislation that reflects public demand. A strategy is to use higher strength materials for parts with reduced cross-sections. However, such materials are less formable than traditional grades. The frequent result is increased processing and piece costs. 3D roll forming is a novel and flexible process: it is estimated that a quarter of the structure of a vehicle can be made with a single set of tooling. Unlike stamping, this process requires material with low work hardening rates. In this paper, we present results of ultra high strength steels that have low elongation in a tension but display high formability in bending through the suppression of the necking response.

The NOνA Module Factory Quality Assurance System

NASA Astrophysics Data System (ADS)

Smith, Alex; the NOνA Collaboration

The NOνA experiment will measure neutrino oscillations using a long-baseline beam, a ∼220-ton near detector and a ∼14-kiloton far detector. Production of ∼12500 modules to build these detectors is an industrial scale operation requiring careful quality assurance to meet the stringent technical specifications. Unlike a typical industrial operation, this project will use primarily a part time labor force of ∼200 University of Minnesota undergraduate students managed by a small team of full time employees. The quality assurance system is involved in nearly every aspect of the production: assembly, scheduling, training, payroll, materials, machine maintenance, test data, and safety compliance. The quality assurance data collected during the assembly process allows us to quickly identify and correct any problems that arise.

Indexing system for optical beam steering

NASA Technical Reports Server (NTRS)

Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.

1990-01-01

This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

Qualification of safety-related electrical equipment in France. Methods, approach and test facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raimondo, E.; Capman, J.L.; Herovard, M.

1985-05-01

Requirements for qualification of electrical equipment used in French-built nuclear power plants are stated in a national code, the RCC-E, or Regles de Construction et de Conception des Materiels Electriques. Under the RCC-E, safety related equipment is assigned to one of three different categories, according to location in the plant and anticipated normal, accident and post-accident behavior. Qualification tests differ for each category and procedures range in scope from the standard seismic test to the highly stringent VISA program, which specifies a predetermined sequence of aging, radiation, seismic and simulated accident testing. A network of official French test facilities wasmore » developed specifically to meet RCC-E requirements.« less

Orion Spacecraft MMOD Protection Design and Assessment

NASA Technical Reports Server (NTRS)

Bohl, W.; Miller, J.; Deighton, K.; Yasensky, J.; Foreman C.; Christiansen, Eric; Hyde, J.; Nahra, H.

2010-01-01

The Orion spacecraft will replace the Space Shuttle Orbiter for American and international partner access to the International Space Station by 2015 and, afterwards, for access to the moon for initial sorties and later for extended outpost visits as part of the Constellation Exploration Initiative. This work describes some of the efforts being undertaken to ensure that the Constellation Program, Orion Crew Exploration Vehicle design will meet or exceed the stringent micrometeoroid and orbital debris (MMOD) requirements set out by NASA when exposed to the environments encountered with these missions. This paper will provide a brief overview of the approaches being used to provide MMOD protection to the Orion vehicle and to assess the spacecraft for compliance to the Constellation Program s MMOD requirements.

Basics of Compounding: Compounding Irrigation Solutions for Sterile and Nonsterile Preparations.

PubMed

Allen, Loyd V

2017-01-01

Compounding pharmacists are sometimes called upon to prepare irrigation solutions, especially in the hospital or clinical setting. Irrigations are indicated for washing or bathing surgical incisions, wounds, and body tissues, including body cavities. Some irrigation solutions coming in contact with exposed tissue, must meet stringent requirements of sterility and bacterial endotoxins. Compounded irrigation solutions may involve wound(s), the bladder, and also may be for ophthalmic, otic, and nasal application. Some vaginal douches/instillations and rectal solutions may also be used as irrigations. As with any medication administered to the body or used on body tissues, there are requirements, and these may vary depending on the type of irrigation solution involved. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

A Dependable Massive Storage Service for Medical Imaging.

PubMed

Núñez-Gaona, Marco Antonio; Marcelín-Jiménez, Ricardo; Gutiérrez-Martínez, Josefina; Aguirre-Meneses, Heriberto; Gonzalez-Compean, José Luis

2018-05-18

We present the construction of Babel, a distributed storage system that meets stringent requirements on dependability, availability, and scalability. Together with Babel, we developed an application that uses our system to store medical images. Accordingly, we show the feasibility of our proposal to provide an alternative solution for massive scientific storage and describe the software architecture style that manages the DICOM images life cycle, utilizing Babel like a virtual local storage component for a picture archiving and communication system (PACS-Babel Interface). Furthermore, we describe the communication interface in the Unified Modeling Language (UML) and show how it can be extended to manage the hard work associated with data migration processes on PACS in case of updates or disaster recovery.

Advanced technology needs for a global change science program: Perspective of the Langley Research Center

NASA Technical Reports Server (NTRS)

Rowell, Lawrence F.; Swissler, Thomas J.

1991-01-01

The focus of the NASA program in remote sensing is primarily the Earth system science and the monitoring of the Earth global changes. One of NASA's roles is the identification and development of advanced sensing techniques, operational spacecraft, and the many supporting technologies necessary to meet the stringent science requirements. Langley Research Center has identified the elements of its current and proposed advanced technology development program that are relevant to global change science according to three categories: sensors, spacecraft, and information system technologies. These technology proposals are presented as one-page synopses covering scope, objective, approach, readiness timeline, deliverables, and estimated funding. In addition, the global change science requirements and their measurement histories are briefly discussed.

Tire and runway surface research

NASA Technical Reports Server (NTRS)

Yager, Thomas J.

1986-01-01

The condition of aircraft tires and runway surfaces can be crucial in meeting the stringent demands of aircraft ground operations, particularly under adverse weather conditions. Gaining a better understanding of the factors influencing the tire/pavement interface is the aim of several ongoing NASA Langley research programs which are described in this paper. Results from several studies conducted at the Langley Aircraft Landing Dynamics Facility, tests with instrumented ground vehicles and aircraft, and some recent aircraft accident investigations are summarized to indicate effects of different tire and runway properties. The Joint FAA/NASA Runway Friction Program is described together with some preliminary test findings. The scope of future NASA Langley research directed towards solving aircraft ground operational problems related to the tire/pavement interface is given.

Influence of Design Variations on Systems Performance

NASA Technical Reports Server (NTRS)

Tumer, Irem Y.; Stone, Robert B.; Huff, Edward M.; Norvig, Peter (Technical Monitor)

2000-01-01

High-risk aerospace components have to meet very stringent quality, performance, and safety requirements. Any source of variation is a concern, as it may result in scrap or rework. poor performance, and potentially unsafe flying conditions. The sources of variation during product development, including design, manufacturing, and assembly, and during operation are shown. Sources of static and dynamic variation during development need to be detected accurately in order to prevent failure when the components are placed in operation. The Systems' Health and Safety (SHAS) research at the NASA Ames Research Center addresses the problem of detecting and evaluating the statistical variation in helicopter transmissions. In this work, we focus on the variations caused by design, manufacturing, and assembly of these components, prior to being placed in operation (DMV). In particular, we aim to understand and represent the failure and variation information, and their correlation to performance and safety and feed this information back into the development cycle at an early stage. The feedback of such critical information will assure the development of more reliable components with less rework and scrap. Variations during design and manufacturing are a common source of concern in the development and production of such components. Accounting for these variations, especially those that have the potential to affect performance, is accomplished in a variety ways, including Taguchi methods, FMEA, quality control, statistical process control, and variation risk management. In this work, we start with the assumption that any of these variations can be represented mathematically, and accounted for by using analytical tools incorporating these mathematical representations. In this paper, we concentrate on variations that are introduced during design. Variations introduced during manufacturing are investigated in parallel work.

Application of telecom planar lightwave circuits for homeland security sensing

NASA Astrophysics Data System (ADS)

Veldhuis, Gert J.; Elders, Job; van Weerden, Harm; Amersfoort, Martin

2004-03-01

Over the past decade, a massive effort has been made in the development of planar lightwave circuits (PLCs) for application in optical telecommunications. Major advances have been made, on both the technological and functional performance front. Highly sophisticated software tools that are used to tailor designs to required functional performance support these developments. In addition extensive know-how in the field of packaging, testing, and failure mode and effects analysis (FMEA) has been built up in the struggle for meeting the stringent Telcordia requirements that apply to telecom products. As an example, silica-on-silicon is now a mature technology available at several industrial foundries around the world, where, on the performance front, the arrayed-waveguide grating (AWG) has evolved into an off-the-shelf product. The field of optical chemical-biological (CB) sensors for homeland security application can greatly benefit from the advances as described above. In this paper we discuss the currently available technologies, device concepts, and modeling tools that have emerged from the telecommunications arena and that can effectively be applied to the field of homeland security. Using this profound telecom knowledge base, standard telecom components can readily be tailored for detecting CB agents. Designs for telecom components aim at complete isolation from the environment to exclude impact of environmental parameters on optical performance. For sensing applications, the optical path must be exposed to the measurand, in this area additional development is required beyond what has already been achieved in telecom development. We have tackled this problem, and are now in a position to apply standard telecom components for CB sensing. As an example, the application of an AWG as a refractometer is demonstrated, and its performance evaluated.

Advances in structural monitoring with Global Positioning System technology: 1997-2006

NASA Astrophysics Data System (ADS)

Ogaja, Clement; Li, Xiaojing; Rizos, Chris

2007-11-01

Over the last decade, users of the Global Positioning System (GPS) have developed the technology capable of meeting stringent requirements to study the dynamics of tall buildings, towers, and bridges during earthquakes, wind-induced deformation and traffic loading. Dynamic measurements of relative displacements of structures is currently possible using real-time kinematic (RTK) positioning techniques, now advanced to record typically at 10-20 Hz (or higher - e.g., 100 Hz) with an accuracy of ±1 cm horizontally and ±2 cm vertically. With further advances in the technology and improvements in sampling capability, it is possible to meet the needs of real-time displacement information for the structural engineering community. After a decade of great strides in proving the feasibility of the technology, focus is moving to sensor integration and operational systems. Several investigators are now routinely researching the integration of GPS with other sensors (accelerometers, fibre optics, pseudolites, etc.) to utilise the complementary benefits and overcome limitations of the individual systems. Examples of real-time operational systems exist to demonstrate the significance of GPS technology in measuring the dynamic behaviour of large engineering structures.

Design and CFD analysis of intake port and exhaust port for a 4 valve cylinder head engine

NASA Astrophysics Data System (ADS)

Latheesh, V. M.; Parthasarathy, P.; Baskaran, V.; Karthikeyan, S.

2018-02-01

In cylinder air motion in a compression ignition engine effects mixing of air-fuel, quality of combustion and emission produced. The primary objective is to design and analyze intake and the exhaust port for a four valve cylinder head to meet higher emission norms for a given diesel engine with two valves. In this work, an existing cylinder head designed for two valves was redesigned with 4 valves. The modern trend also confirms this approach. This is being followed in the design and development of new generation engines to meet the stringent environment norms, competition in market and demand for more fuel-efficient engines. The swirl ratio and flow coefficient were measured for different valve lifts using STAR CCM+. CFD results were validated with the two-valve cylinder experimental results. After validation, a comparison between two-valve and four-valve cylinder head was done. The conversion of two valve cylinder head to 4 valves may not support modern high swirl generating port layout and requires a trade-off between many design parameters.

A military grade, field usable, Raman analyzer: measurement of captured fuel

NASA Astrophysics Data System (ADS)

Farquharson, Stuart; Smith, Wayne; Shende, Chetan; Patient, Michael; Huang, Hermes; Brouillette, Carl

2014-05-01

Portable Raman analyzers have emerged during the first part of this century as an important field tool for crime scene and forensic analysis, primarily for their ability to identify unknown substances. This ability is also important to the US military, which has been investigating such analyzers for identification of explosive materials that may be used to produce improvised explosive devices, chemicals that may be used to produce chemical warfare agents, and fuels in storage tanks that may be used to power US military vehicles. However, the use of such portable analyzers requires that they meet stringent military standards (specifically MIL-STD 810G). These requirements include among others: 1) light weight and small size (< 35 pounds, < 3 cu. ft.), 2) vibration and shock resistant (26 four foot drops), 3) operation from -4 to 110 oF, 4) operation in blowing dust, sand and rain, 5) battery operation, and of course 6) safe operation (no laser or shock hazards). Here we describe a portable Raman analyzer that meets all of these requirements, and its use to determine if captured fuels are suitable for use.

The myriad challenges of the Paris Agreement

NASA Astrophysics Data System (ADS)

Mitchell, Dann; Allen, Myles R.; Hall, Jim W.; Muller, Benito; Rajamani, Lavanya; Le Quéré, Corinne

2018-05-01

The much awaited and intensely negotiated Paris Agreement was adopted on 12 December 2015 by the Parties to the United Nations Framework Convention on Climate Change. The agreement set out a more ambitious long-term temperature goal than many had anticipated, implying more stringent emissions reductions that have been under-explored by the research community. By its very nature a multidisciplinary challenge, filling the knowledge gap requires not only climate scientists, but the whole Earth system science community, as well as economists, engineers, lawyers, philosophers, politicians, emergency planners and others to step up. To kick start cross-disciplinary discussions, the University of Oxford's Environmental Change Institute focused its 25th anniversary conference upon meeting the challenges of the Paris Agreement for science and society. This theme issue consists of review papers, opinion pieces and original research from some of the presentations within that meeting, covering a wide range of issues underpinning the Paris Agreement. This article is part of the theme issue `The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.

The myriad challenges of the Paris Agreement.

PubMed

Mitchell, Dann; Allen, Myles R; Hall, Jim W; Muller, Benito; Rajamani, Lavanya; Le Quéré, Corinne

2018-05-13

The much awaited and intensely negotiated Paris Agreement was adopted on 12 December 2015 by the Parties to the United Nations Framework Convention on Climate Change. The agreement set out a more ambitious long-term temperature goal than many had anticipated, implying more stringent emissions reductions that have been under-explored by the research community. By its very nature a multidisciplinary challenge, filling the knowledge gap requires not only climate scientists, but the whole Earth system science community, as well as economists, engineers, lawyers, philosophers, politicians, emergency planners and others to step up. To kick start cross-disciplinary discussions, the University of Oxford's Environmental Change Institute focused its 25th anniversary conference upon meeting the challenges of the Paris Agreement for science and society. This theme issue consists of review papers, opinion pieces and original research from some of the presentations within that meeting, covering a wide range of issues underpinning the Paris Agreement.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'. © 2018 The Author(s).

The myriad challenges of the Paris Agreement

PubMed Central

Mitchell, Dann; Allen, Myles R.; Hall, Jim W.; Muller, Benito; Rajamani, Lavanya; Le Quéré, Corinne

2018-01-01

The much awaited and intensely negotiated Paris Agreement was adopted on 12 December 2015 by the Parties to the United Nations Framework Convention on Climate Change. The agreement set out a more ambitious long-term temperature goal than many had anticipated, implying more stringent emissions reductions that have been under-explored by the research community. By its very nature a multidisciplinary challenge, filling the knowledge gap requires not only climate scientists, but the whole Earth system science community, as well as economists, engineers, lawyers, philosophers, politicians, emergency planners and others to step up. To kick start cross-disciplinary discussions, the University of Oxford's Environmental Change Institute focused its 25th anniversary conference upon meeting the challenges of the Paris Agreement for science and society. This theme issue consists of review papers, opinion pieces and original research from some of the presentations within that meeting, covering a wide range of issues underpinning the Paris Agreement. This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'. PMID:29610376

Stringent homology-based prediction of H. sapiens-M. tuberculosis H37Rv protein-protein interactions

PubMed Central

2014-01-01

Background H. sapiens-M. tuberculosis H37Rv protein-protein interaction (PPI) data are essential for understanding the infection mechanism of the formidable pathogen M. tuberculosis H37Rv. Computational prediction is an important strategy to fill the gap in experimental H. sapiens-M. tuberculosis H37Rv PPI data. Homology-based prediction is frequently used in predicting both intra-species and inter-species PPIs. However, some limitations are not properly resolved in several published works that predict eukaryote-prokaryote inter-species PPIs using intra-species template PPIs. Results We develop a stringent homology-based prediction approach by taking into account (i) differences between eukaryotic and prokaryotic proteins and (ii) differences between inter-species and intra-species PPI interfaces. We compare our stringent homology-based approach to a conventional homology-based approach for predicting host-pathogen PPIs, based on cellular compartment distribution analysis, disease gene list enrichment analysis, pathway enrichment analysis and functional category enrichment analysis. These analyses support the validity of our prediction result, and clearly show that our approach has better performance in predicting H. sapiens-M. tuberculosis H37Rv PPIs. Using our stringent homology-based approach, we have predicted a set of highly plausible H. sapiens-M. tuberculosis H37Rv PPIs which might be useful for many of related studies. Based on our analysis of the H. sapiens-M. tuberculosis H37Rv PPI network predicted by our stringent homology-based approach, we have discovered several interesting properties which are reported here for the first time. We find that both host proteins and pathogen proteins involved in the host-pathogen PPIs tend to be hubs in their own intra-species PPI network. Also, both host and pathogen proteins involved in host-pathogen PPIs tend to have longer primary sequence, tend to have more domains, tend to be more hydrophilic, etc. And the protein domains from both host and pathogen proteins involved in host-pathogen PPIs tend to have lower charge, and tend to be more hydrophilic. Conclusions Our stringent homology-based prediction approach provides a better strategy in predicting PPIs between eukaryotic hosts and prokaryotic pathogens than a conventional homology-based approach. The properties we have observed from the predicted H. sapiens-M. tuberculosis H37Rv PPI network are useful for understanding inter-species host-pathogen PPI networks and provide novel insights for host-pathogen interaction studies. Reviewers This article was reviewed by Michael Gromiha, Narayanaswamy Srinivasan and Thomas Dandekar. PMID:24708540

Mobile Router Technology Development

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Stewart, David H.; Bell, Terry L.; Kachmar, Brian A.; Shell, Dan; Leung, Kent

2002-01-01

Cisco Systems and NASA have been performing joint research on mobile routing technology under a NASA Space Act Agreement. Cisco developed mobile router technology and provided that technology to NASA for applications to aeronautic and space-based missions. NASA has performed stringent performance testing of the mobile router, including the interaction of routing and transport-level protocols. This paper describes mobile routing, the mobile router, and some key configuration parameters. In addition, the paper describes the mobile routing test network and test results documenting the performance of transport protocols in dynamic routing environments.

Are More Stringent NCLB State Accountability Systems Associated with Better Student Outcomes? An Analysis of NAEP Results across States

ERIC Educational Resources Information Center

Wei, Xin

2012-01-01

This study developed a comprehensive measure of the stringency level of NCLB states' accountability systems, including the strength of their annual measurable objectives, confidence intervals, performance indexing, retesting, minimum subgroup size, and the difficulty levels of proficiency standards. This study related accountability stringency in…

Neoliberal Competition in Higher Education Today: Research, Accountability and Impact

ERIC Educational Resources Information Center

Olssen, Mark

2016-01-01

Drawing on Foucault's elaboration of neoliberalism as a positive form of state power, the ascendancy of neoliberalism in higher education in Britain is examined in terms of the displacement of public good models of governance, and their replacement with individualised incentives and performance targets, heralding new and more stringent conceptions…

A high-temperature furnace for applications in microgravity

NASA Technical Reports Server (NTRS)

1991-01-01

Technology in the area of material processing and crystal growth has been greatly furthered by research in microgravity environments. The role of efficient, lightweight furnaces with reliable performance is crucial in these experiments. A need exists for the development of a readily duplicated, high-temperature furnace satisfying stringent weight, volume, and power constraints. A furnace was designed and is referred to as the UAH SHIELD. Stringent physical and operating characteristics for the system were specified, including a maximum weight of 20 kg, a maximum power requirement of 60 W, and a volume of the furnace assembly, excluding the batteries, limited to half a Get-Away-Special canister. The UAH SHIELD furnace uses radiation shield and vacuum technology applied in the form of a series of concentric cylinders enclosed on either end with disks. Thermal testing of a furnace prototype was performed in addition to some thermal and structural analysis. Results indicate the need for spacing of the shields to accommodate the thermal expansion during furnace operation. In addition, a power dissipation of approximately 100 W and system weight of approximately 30 kg was found for the current design.

Fabrication and Improvement of Lmsc's All-silica RSI

NASA Technical Reports Server (NTRS)

Beasley, R. M.; Izu, Y. D.; Nakano, H. N.; Ozolin, A. A.; Peachman, A.

1973-01-01

The LI-1500 and LI-900 all silica RSI materials have made the transition from laboratory to manufacturing operation. Improvements in both quality and reproducibility have been achieved. The LI-1500 material has displayed superior reliability in evaluations conducted at various facilities. The dependable performance of the material is attributed to the adherence to the stringent requirements of the numerous material, process, and product control evaluations and inspection points performed during manufacture.

Do Contemporary Randomized Controlled Trials Meet ESMO Thresholds for Meaningful Clinical Benefit?

PubMed

Del Paggio, J C; Azariah, B; Sullivan, R; Hopman, W M; James, F V; Roshni, S; Tannock, I F; Booth, C M

2017-01-01

The European Society for Medical Oncology (ESMO) recently released a magnitude of clinical benefit scale (ESMO-MCBS) for systemic therapies for solid cancers. Here, we evaluate contemporary randomized controlled trials (RCTs) against the proposed ESMO thresholds for meaningful clinical benefit. RCTs evaluating systemic therapy for breast cancer, nonsmall cell lung cancer (NSCLC), colorectal cancer (CRC), and pancreatic cancer published 2011-2015 were reviewed. Data were abstracted regarding trial characteristics and outcomes, and these were applied to the ESMO-MCBS. We also determined whether RCTs were designed to detect an effect that would meet clinical benefit as defined by the ESMO-MCBS. About 277 eligible RCTs were included (40% breast, 31% NSCLC, 22% CRC, 6% pancreas). Median sample size was 532 and 83% were funded by industry. Among all 277 RCTs, the experimental therapy was statistically superior to the control arm in 138 (50%) trials: results of only 31% (43/138) of these trials met the ESMO-MCBS clinical benefit threshold. RCTs with curative intent were more likely to meet clinically meaningful thresholds than those with palliative intent [61% (19/31) versus 22% (24/107), P < 0.001]. Among the 226 RCTs for which the ESMO-MCBS could be applied, 31% (70/226) were designed to detect an effect size that could meet ESMO-MCBS thresholds. Less than one-third of contemporary RCTs with statistically significant results meet ESMO thresholds for meaningful clinical benefit, and this represents only 15% of all published trials. Investigators, funding agencies, regulatory agencies, and industry should adopt more stringent thresholds for meaningful benefit in the design of future RCTs. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Evaluation of Beckman Coulter DxI 800 immunoassay system using clinically oriented performance goals.

PubMed

Akbas, Neval; Schryver, Patricia G; Algeciras-Schimnich, Alicia; Baumann, Nikola A; Block, Darci R; Budd, Jeffrey R; Gaston, S J Stephen; Klee, George G

2014-11-01

We evaluated the analytical performance of 24 immunoassays using the Beckman Coulter DxI 800 immunoassay systems at Mayo Clinic, Rochester, MN for trueness, precision, detection limits, linearity, and consistency (across instruments and reagent lots). Clinically oriented performance goals were defined using the following methods: trueness-published desirable accuracy limits, precision-published desirable biologic variation; detection limits - 0.1 percentile of patient test values, linearity - 50% of total error, and consistency-percentage test values crossing key decision points. Local data were collected for precision, linearity, and consistency. Data were provided by Beckman Coulter, Inc. for trueness and detection limits. All evaluated assays except total thyroxine were within the proposed goals for trueness. Most of the assays met the proposed goals for precision (86% of intra-assay results and 75% of inter-assay results). Five assays had more than 15% of the test results below the minimum detection limits. Carcinoembryonic antigen, total thyroxine and free triiodothyronine exceeded the proposed goals of ±6.3%, ±5% and ±5.7% for dilution linearity. All evaluated assays were within the proposed goals for instrument consistency. Lot-to-lot consistency results for cortisol, ferritin and total thyroxine exceeded the proposed goals of 3.3%, 11.4% and 7% at one medical decision level, while vitamin B12 exceeded the proposed goals of 5.2% and 3.8% at two decision levels. The Beckman Coulter DxI 800 immunoassay system meets most of these proposed goals, even though these clinically focused performance goals represent relatively stringent limits. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Global Space-Based Inter-Calibration System Reflective Solar Calibration Reference: From Aqua MODIS to S-NPP VIIRS

NASA Technical Reports Server (NTRS)

Xiong, Xiaoxiong; Angal, Amit; Butler, James; Cao, Changyong; Doelling, Daivd; Wu, Aisheng; Wu, Xiangqian

2016-01-01

The MODIS has successfully operated on-board the NASA's EOS Terra and Aqua spacecraft for more than 16 and 14 years, respectively. MODIS instrument was designed with stringent calibration requirements and comprehensive on-board calibration capability. In the reflective solar spectral region, Aqua MODIS has performed better than Terra MODIS and, therefore, has been chosen by the Global Space-based Inter-Calibration System (GSICS) operational community as the calibration reference sensor in cross-sensor calibration and calibration inter-comparisons. For the same reason, it has also been used by a number of earth observing sensors as their calibration reference. Considering that Aqua MODIS has already operated for nearly 14 years, it is essential to transfer its calibration to a follow-on reference sensor with a similar calibration capability and stable performance. The VIIRS is a follow-on instrument to MODIS and has many similar design features as MODIS, including their on-board calibrators (OBC). As a result, VIIRS is an ideal candidate to replace MODIS to serve as the future GSICS reference sensor. Since launch, the S-NPP VIIRS has already operated for more than 4 years and its overall performance has been extensively characterized and demonstrated to meet its overall design requirements. This paper provides an overview of Aqua MODIS and S-NPP VIIRS reflective solar bands (RSB) calibration methodologies and strategies, traceability, and their on-orbit performance. It describes and illustrates different methods and approaches that can be used to facilitate the calibration reference transfer, including the use of desert and Antarctic sites, deep convective clouds (DCC), and the lunar observations.

X-ray Cryogenic Facility (XRCF) Handbook

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey R.

2016-01-01

The X-ray & Cryogenic Facility (XRCF) Handbook is a guide for planning operations at the facility. A summary of the capabilities, policies, and procedures is provided to enhance project coordination between the facility user and XRCF personnel. This handbook includes basic information that will enable the XRCF to effectively plan and support test activities. In addition, this handbook describes the facilities and systems available at the XRCF for supporting test operations. 1.2 General Facility Description The XRCF was built in 1989 to meet the stringent requirements associated with calibration of X-ray optics, instruments, and telescopes and was subsequently modified in 1999 & 2005 to perform the challenging cryogenic verification of Ultraviolet, Optical, and Infrared mirrors. These unique and premier specialty capabilities, coupled with its ability to meet multiple generic thermal vacuum test requirements for large payloads, make the XRCF the most versatile and adaptable space environmental test facility in the Agency. XRCF is also recognized as the newest, most cost effective, most highly utilized facility in the portfolio and as one of only five NASA facilities having unique capabilities. The XRCF is capable of supporting and has supported missions during all phases from technology development to flight verification. Programs/projects that have benefited from XRCF include Chandra, Solar X-ray Imager, Hinode, and James Webb Space Telescope. All test programs have been completed on-schedule and within budget and have experienced no delays due to facility readiness or failures. XRCF is currently supporting Strategic Astrophysics Technology Development for Cosmic Origins. Throughout the years, XRCF has partnered with and continues to maintain positive working relationships with organizations such as ATK, Ball Aerospace, Northrop Grumman Aerospace, Excelis (formerly Kodak/ITT), Smithsonian Astrophysical Observatory, Goddard Space Flight Center, University of Alabama Huntsville, and more.

Logistics, Costs, and GHG Impacts of Utility-Scale Co-Firing with 20% Biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichol, Corrie Ian

This study analyzes the possibility that biopower in the U.S. is a cost-competitive option to significantly reduce greenhouse gas emissions. In 2009, net greenhouse gas (GHG) emitted in the United States was equivalent to 5,618 million metric tons CO 2, up 5.6% from 1990 (EPA 2011). Coal-fired power generation accounted for 1,748 million metric tons of this total. Intuitively, life-cycle CO 2 emissions in the power sector could be reduced by substituting renewable biomass for coal. If just 20% of the coal combusted in 2009 had been replaced with biomass, CO 2 emissions would have been reduced by 350 millionmore » metric tons, or about 6% of net annual GHG emission. This would have required approximately 225 million tons of dry biomass. Such an ambitious fuel substitution would require development of a biomass feedstock production and supply system tantamount to coal. This material would need to meet stringent specifications to ensure reliable conveyance to boiler burners, efficient combustion, and no adverse impact on heat transfer surfaces and flue gas cleanup operations. Therefore, this report addresses the potential cost/benefit tradeoffs of co-firing 20% specification-qualified biomass (on an energy content basis) in large U.S. coal-fired power plants. The dependence and sensitivity of feedstock cost on source of material, location, supply distance, and demand pressure was established. Subsequently, the dependence of levelized cost of electricity (LCOE) on feedstock costs, power plant feed system retrofit, and impact on boiler performance was determined. Overall life-cycle assessment (LCA) of greenhouse gas emissions saving were next evaluated and compared to wind and solar energy to benchmark the leading alternatives for meeting renewable portfolio standards (or RPS).« less

Reaching 1 m deep on Mars: the Icebreaker drill.

PubMed

Zacny, K; Paulsen, G; McKay, C P; Glass, B; Davé, A; Davila, A F; Marinova, M; Mellerowicz, B; Heldmann, J; Stoker, C; Cabrol, N; Hedlund, M; Craft, J

2013-12-01

The future exploration of Mars will require access to the subsurface, along with acquisition of samples for scientific analysis and ground-truthing of water ice and mineral reserves for in situ resource utilization. The Icebreaker drill is an integral part of the Icebreaker mission concept to search for life in ice-rich regions on Mars. Since the mission targets Mars Special Regions as defined by the Committee on Space Research (COSPAR), the drill has to meet the appropriate cleanliness standards as requested by NASA's Planetary Protection Office. In addition, the Icebreaker mission carries life-detection instruments; and in turn, the drill and sample delivery system have to meet stringent contamination requirements to prevent false positives. This paper reports on the development and testing of the Icebreaker drill, a 1 m class rotary-percussive drill and triple redundant sample delivery system. The drill acquires subsurface samples in short, approximately 10 cm bites, which makes the sampling system robust and prevents thawing and phase changes in the target materials. Autonomous drilling, sample acquisition, and sample transfer have been successfully demonstrated in Mars analog environments in the Arctic and the Antarctic Dry Valleys, as well as in a Mars environmental chamber. In all environments, the drill has been shown to perform at the "1-1-100-100" level; that is, it drilled to 1 m depth in approximately 1 hour with less than 100 N weight on bit and approximately 100 W of power. The drilled substrate varied and included pure ice, ice-rich regolith with and without rocks and with and without 2% perchlorate, and whole rocks. The drill is currently at a Technology Readiness Level (TRL) of 5. The next-generation Icebreaker drill weighs 10 kg, which is representative of the flightlike model at TRL 5/6.

Solar Heating And Cooling Of Buildings (SHACOB): Requirements definition and impact analysis-2. Volume 1: Energy-conserving design for residential structures

NASA Astrophysics Data System (ADS)

Cretcher, C. K.

1980-11-01

The impact of stringent energy conserving building standards on electric utility service areas and their customers was analyzed. The demands on the seven broadly representative electric utilities were aggregated to represent the total new construction electric heating demands in the years 1990 and 2000 to be compared to the aggregate obtained similarly for a nominal, less stringent standard, viz., ASHRAE 90-75. Results presented include the percentage of energy savings achieved in both heating and cooling seasons and typical demand profile changes. A utility economic impact analysis was performed for the cases investigated to determine changes in operating costs and potential capacity sales. A third cost component considered is the incremental cost of superinsulation (over ASHRAE 90-75) to the customer. The aggregate net cost to the utility/customer entity is utilized as a measure of overall economic benefit.

The aerodynamic design of an advanced rotor airfoil

NASA Technical Reports Server (NTRS)

Blackwell, J. A., Jr.; Hinson, B. L.

1978-01-01

An advanced rotor airfoil, designed utilizing supercritical airfoil technology and advanced design and analysis methodology is described. The airfoil was designed subject to stringent aerodynamic design criteria for improving the performance over the entire rotor operating regime. The design criteria are discussed. The design was accomplished using a physical plane, viscous, transonic inverse design procedure, and a constrained function minimization technique for optimizing the airfoil leading edge shape. The aerodynamic performance objectives of the airfoil are discussed.

75 FR 32611 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-08

... implement more stringent standards for stationary compression ignition engines with displacement greater... engines with displacement at or above 30 liters per cylinder to align more closely with recent standards.... Standards for New Engines With Displacement Greater Than or Equal to 10 l/cyl and Less Than 30 l/cyl B...

Design and Evaluation of Energy Efficient Modular Classroom Structures.

ERIC Educational Resources Information Center

Brown, G. Z.; And Others

This paper describes a study that developed innovations that would enable modular builders to improve the energy performance of their classrooms without increasing their first cost. The Modern Building Systems' classroom building conforms to the stringent Oregon and Washington energy codes, and, at $18 per square foot, it is at the low end of the…

Flow condensation on copper-based nanotextured superhydrophobic surfaces.

PubMed

Torresin, Daniele; Tiwari, Manish K; Del Col, Davide; Poulikakos, Dimos

2013-01-15

Superhydrophobic surfaces have shown excellent ability to promote dropwise condensation with high droplet mobility, leading to enhanced surface thermal transport. To date, however, it is unclear how superhydrophobic surfaces would perform under the stringent flow condensation conditions of saturated vapor at high temperature, which can affect superhydrophobicity. Here, we investigate this issue employing "all-copper" superhydrophobic surfaces with controlled nanostructuring for minimal thermal resistance. Flow condensation tests performed with saturated vapor at a high temperature (110 °C) showed the condensing drops penetrate the surface texture (i.e., attain the Wenzel state with lower droplet mobility). At the same time, the vapor shear helped ameliorate the mobility and enhanced the thermal transport. At the high end of the examined vapor velocity range, a heat flux of ~600 kW m(-2) was measured at 10 K subcooling and 18 m s(-1) vapor velocity. This clearly highlights the excellent potential of a nanostructured superhydrophobic surface in flow condensation applications. The surfaces sustained dropwise condensation and vapor shear for five days, following which mechanical degradation caused a transition to filmwise condensation. Overall, our results underscore the need to investigate superhydrophobic surfaces under stringent and realistic flow condensation conditions before drawing conclusions regarding their performance in practically relevant condensation applications.

NOx adsorber and method of regenerating same

DOEpatents

Endicott, Dennis L [Peoria, IL; Verkiel, Maarten [Metamora, IL; Driscoll, James J [Dunlap, IL

2007-01-30

New technologies, such as NOx adsorber catalytic converters, are being used to meet increasingly stringent regulations on undesirable emissions, including NOx emissions. NOx adsorbers must be periodically regenerated, which requires an increased fuel consumption. The present disclosure includes a method of regenerating a NOx adsorber within a NOx adsorber catalytic converter. At least one sensor positioned downstream from the NOx adsorber senses, in the downstream exhaust, at least one of NOx, nitrous oxide and ammonia concentrations a plurality of times during a regeneration phase. The sensor is in communication with an electronic control module that includes a regeneration monitoring algorithm operable to end the regeneration phase when a time rate of change of the at least one of NOx, nitrous oxide and ammonia concentrations is after an expected plateau region begins.

Analysis of Energy Intensive Enterprises under EU Emission Trading System in Latvia

NASA Astrophysics Data System (ADS)

Zahare, Dace; Rosa, Marika

2011-01-01

Climate change and global warming has become one of the main topics worldwide. The European Union Emission Trading System (EU ETS) was established to limit climate change, providing regulations which encourage companies to invest in cleaner production and more energy efficient production. Latvian energy intensive enterprises are operating under the EU ETS from the year 2005. The main goal of this paper is to provide an analysis of energy intensive installations in terms of their energy efficiency. Additionally, an analysis of EU ETS phase III which will start to operate in 2013 under new, more stringent rules has been conducted by modelling three Latvian energy intensive enterprise operations under this phase and estimating the barriers to meet the goal of the EU ETS phase III.

Space Research Fortifies Nutrition Worldwide

NASA Technical Reports Server (NTRS)

2008-01-01

NASA's Controlled Ecological Life Support Systems program attempted to address basic needs of crews, meet stringent payload and power usage restrictions, and minimize space occupancy, by developing living, regenerative ecosystems that would take care of themselves and their inhabitants. An experiment from this program evolved into one of the most widespread NASA spinoffs of all time-a method for manufacturing an algae-based food supplement that provides the nutrients previously only available in breast milk. Martek Biosciences Corporation, in Columbia, Maryland, now manufactures this supplement, and it can be found in over 90 percent of the infant formulas sold in the United States, as well as those sold in over 65 other countries. With such widespread use, the company estimates that over 24 million babies worldwide have consumed its nutritional additives.

Non-destructive thermo-mechanical behavior assessment of glass-ceramics for dental applications

NASA Astrophysics Data System (ADS)

Kordatos, E. Z.; Abdulkadhim, Z.; Feteira, A. M.

2017-05-01

Every year millions of people seek dental treatment to either repair damaged, unaesthetic and dysfunctional teeth or replace missing natural teeth. Several dental materials have been developed to meet the stringent requirements in terms of mechanical properties, aesthetics and chemical durability in the oral environment. Glass-ceramics exhibit a suitable combination of these properties for dental restorations. This research is focused on the assessment of the thermomechanical behavior of bio-ceramics and particularly lithium aluminosilicate glass-ceramics (LAS glass-ceramics). Specifically, methodologies based on Infrared Thermography (IRT) have been applied in order the structure - property relationship to be evaluated. Non-crystallized, partially crystallized and fully crystallized glass-ceramic samples have been non-destructively assessed in order their thermo-mechanical behavior to be associated with their micro-structural features.

Multiphysics Analysis of Frequency Detuning in Superconducting RF Cavities for Proton Particle Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Awida, M. H.; Gonin, I.; Passarelli, D.

2016-01-22

Multiphysics analyses for superconducting cavities are essential in the course of cavity design to meet stringent requirements on cavity frequency detuning. Superconducting RF cavities are the core accelerating elements in modern particle accelerators whether it is proton or electron machine, as they offer extremely high quality factors thus reducing the RF losses per cavity. However, the superior quality factor comes with the challenge of controlling the resonance frequency of the cavity within few tens of hertz bandwidth. In this paper, we investigate how the multiphysics analysis plays a major role in proactively minimizing sources of frequency detuning, specifically; microphonics andmore » Lorentz Force Detuning (LFD) in the stage of RF design of the cavity and mechanical design of the niobium shell and the helium vessel.« less

Beam alignment based on two-dimensional power spectral density of a near-field image.

PubMed

Wang, Shenzhen; Yuan, Qiang; Zeng, Fa; Zhang, Xin; Zhao, Junpu; Li, Kehong; Zhang, Xiaolu; Xue, Qiao; Yang, Ying; Dai, Wanjun; Zhou, Wei; Wang, Yuanchen; Zheng, Kuixing; Su, Jingqin; Hu, Dongxia; Zhu, Qihua

2017-10-30

Beam alignment is crucial to high-power laser facilities and is used to adjust the laser beams quickly and accurately to meet stringent requirements of pointing and centering. In this paper, a novel alignment method is presented, which employs data processing of the two-dimensional power spectral density (2D-PSD) for a near-field image and resolves the beam pointing error relative to the spatial filter pinhole directly. Combining this with a near-field fiducial mark, the operation of beam alignment is achieved. It is experimentally demonstrated that this scheme realizes a far-field alignment precision of approximately 3% of the pinhole size. This scheme adopts only one near-field camera to construct the alignment system, which provides a simple, efficient, and low-cost way to align lasers.

Secondary lead production in Malaysia

NASA Astrophysics Data System (ADS)

Phillips, M. J.; Lim, S. S.

The increase in the number of vehicles and, subsequently, the volume of batteries made by manufacturers in Malaysia have seen a dramatic rise in lead demand over the last five years. Without any lead mines, the only source of lead in Malaysia has been from the recycling of lead/acid batteries. Metal Reclamation (Industries) has commenced the design of a new and advanced secondary lead plant at West Port, Malaysia to meet the increasing demand for lead and the increasingly stringent environmental regulations. The plant is designed to produce up to 75 000 t of lead and lead alloys per year. The plant will also produce, as by-products: polypropylene chips, wallboard-grade gypsum, non-leachable slag for use in construction. A discussion of the process and the products from the new secondary smelter is outlined.

"Reliability Of Fiber Optic Lans"

NASA Astrophysics Data System (ADS)

Code n, Michael; Scholl, Frederick; Hatfield, W. Bryan

1987-02-01

Fiber optic Local Area Network Systems are being used to interconnect increasing numbers of nodes. These nodes may include office computer peripherals and terminals, PBX switches, process control equipment and sensors, automated machine tools and robots, and military telemetry and communications equipment. The extensive shared base of capital resources in each system requires that the fiber optic LAN meet stringent reliability and maintainability requirements. These requirements are met by proper system design and by suitable manufacturing and quality procedures at all levels of a vertically integrated manufacturing operation. We will describe the reliability and maintainability of Codenoll's passive star based systems. These include LAN systems compatible with Ethernet (IEEE 802.3) and MAP (IEEE 802.4), and software compatible with IBM Token Ring (IEEE 802.5). No single point of failure exists in this system architecture.

A highly reliable, autonomous data communication subsystem for an advanced information processing system

NASA Technical Reports Server (NTRS)

Nagle, Gail; Masotto, Thomas; Alger, Linda

1990-01-01

The need to meet the stringent performance and reliability requirements of advanced avionics systems has frequently led to implementations which are tailored to a specific application and are therefore difficult to modify or extend. Furthermore, many integrated flight critical systems are input/output intensive. By using a design methodology which customizes the input/output mechanism for each new application, the cost of implementing new systems becomes prohibitively expensive. One solution to this dilemma is to design computer systems and input/output subsystems which are general purpose, but which can be easily configured to support the needs of a specific application. The Advanced Information Processing System (AIPS), currently under development has these characteristics. The design and implementation of the prototype I/O communication system for AIPS is described. AIPS addresses reliability issues related to data communications by the use of reconfigurable I/O networks. When a fault or damage event occurs, communication is restored to functioning parts of the network and the failed or damage components are isolated. Performance issues are addressed by using a parallelized computer architecture which decouples Input/Output (I/O) redundancy management and I/O processing from the computational stream of an application. The autonomous nature of the system derives from the highly automated and independent manner in which I/O transactions are conducted for the application as well as from the fact that the hardware redundancy management is entirely transparent to the application.

Environmentally regulated aerospace coatings

NASA Technical Reports Server (NTRS)

Morris, Virginia L.

1995-01-01

Aerospace coatings represent a complex technology which must meet stringent performance requirements in the protection of aerospace vehicles. Topcoats and primers are used, primarily, to protect the structural elements of the air vehicle from exposure to and subsequent degradation by environmental elements. There are also many coatings which perform special functions, i.e., chafing resistance, rain erosion resistance, radiation and electric effects, fuel tank coatings, maskants, wire and fastener coatings. The scheduled promulgation of federal environmental regulations for aerospace manufacture and rework materials and processes will regulate the emissions of photochemically reactive precursors to smog and air toxics. Aerospace organizations will be required to identify, qualify and implement less polluting materials. The elimination of ozone depleting chemicals (ODC's) and implementation of pollution prevention requirements are added constraints which must be addressed concurrently. The broad categories of operations affected are the manufacture, operation, maintenance, and repair of military, commercial, general aviation, and space vehicles. The federal aerospace regulations were developed around the precept that technology had to be available to support the reduction of organic and air toxic emissions, i.e., the regulations cannot be technology forcing. In many cases, the regulations which are currently in effect in the South Coast Air Quality Management District (SCAQMD), located in Southern California, were used as the baseline for the federal regulations. This paper addresses strategies used by Southern California aerospace organizations to cope with these regulatory impacts on aerospace productions programs. All of these regulatory changes are scheduled for implementation in 1993 and 1994, with varying compliance dates established.

Advanced Collaborative Emissions Study (ACES)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenbaum, Daniel; Costantini, Maria; Van Erp, Annemoon

2013-12-31

The objective of the Advanced Collaborative Emissions Study (ACES) was to determine before widespread commercial deployment whether or not the new, energy-efficient, heavy duty diesel engines (2007 and 2010 EPA Emissions Standards Compliant) may generate anticipated toxic emissions that could adversely affect the environment and human health. ACES was planned to take place in three phases. In Phase 1, extensive emissions characterization of four production-intent prototype engine and control systems designed to meet 2007 standards for nitrogen oxides (NOx) and particulate matter (PM) was conducted at an existing emissions characterization facility: Southwest Research Institute (SwRI). One of the tested enginesmore » was selected (at random, after careful comparison of results) for health testing in Phase 3. In Phase 2, extensive emission characterization of three production-intent prototype engine and control systems meeting the 2010 standards (including more advanced NOx controls to meet the more stringent 2010 NOx standards) was conducted at the same test facility. In Phase 3, one engine/aftertreatment system selected from Phase 1 was further characterized during health effects studies (at an existing inhalation toxicology laboratory: Lovelace Respiratory Research Institute, [LRRI]) to form the basis of the ACES safety assessment. The Department of Energy (DOE) award provided funding for emissions characterization in Phases 1 and 2 as well as exposure characterization in Phase 3. The main health analyses in Phase 3 were funded separately and are not reported here.« less

MAP Propulsion System Thermal Design

NASA Technical Reports Server (NTRS)

Mosier, Carol L.

2003-01-01

The propulsion system of the Microwave Anisotropy Probe (MAP) had stringent requirements that made the thermal design unique. To meet instrument stability requirements the system had to be designed to keep temperatures of all components within acceptable limits without heater cycling. Although the spacecraft remains at a fixed 22 sun angle at L2, the variations in solar constant, property degradation, and bus voltage range all significantly affect the temperature. Large portions of the fuel lines are external to the structure and all components are mounted to non-conductive composite structure. These two facts made the sensitivity to the MLI effective emissivity and bus temperature very high. Approximately two years prior to launch the propulsion system was redesigned to meet MAP requirements. The new design utilized hardware that was already installed in order to meet schedule constraints. The spacecraft design and the thermal requirements were changed to compensate for inadequacies of the existing hardware. The propulsion system consists of fuel lines, fill and drain lines/valve, eight thrusters, a HXCM, and a propulsion tank. A voltage regulator was added to keep critical components within limits. Software was developed to control the operational heaters. Trim resistors were put in series with each operational heater circuits and the tank survival heater. A highly sophisticated test program, which included real time model correlation, was developed to determine trim resistors sizes. These trim resistors were installed during a chamber break and verified during thermal balance testing.

Overview of innovative remediation of emerging contaminants

NASA Astrophysics Data System (ADS)

Keller, A. A.; Adeleye, A. S.; Huang, Y.; Garner, K.

2015-12-01

The application of nanotechnology in drinking water treatment and pollution cleanup is promising, as demonstrated by a number of field-based (pilot and full scale) and bench scale studies. A number of reviews exist for these nanotechnology-based applications; but to better illustrate its importance and guide its development, a direct comparison between traditional treatment technologies and emerging approaches using nanotechnology is needed. In this review, the performances of traditional technologies and nanotechnology for water treatment and environmental remediation were compared with the goal of providing an up-to-date reference on the state of treatment techniques for researchers, industry, and policy makers. Pollutants were categorized into broad classes, and the most cost-effective techniques (traditional and nanotechnology-based) in each category reported in the literature were compared. Where information was available, cost and environmental implications of both technologies were also compared. Traditional treatment technologies were found to currently offer the most cost-effective choices for removal of several common pollutants from drinking water and polluted sites. Nano-based techniques may however become important in complicated remediation conditions and meeting increasingly stringent water quality standards, especially in removal of emerging pollutants and low levels of contaminants. We also discuss challenges facing environmental application of nanotechnology were also discussed and potential solutions.

Fast force actuators for LSST primary/tertiary mirror

NASA Astrophysics Data System (ADS)

Hileman, Edward; Warner, Michael; Wiecha, Oliver

2010-07-01

The very short slew times and resulting high inertial loads imposed upon the Large Synoptic Survey Telescope (LSST) create new challenges to the primary mirror support actuators. Traditionally large borosilicate mirrors are supported by pneumatic systems, which is also the case for the LSST. These force based actuators bear the weight of the mirror and provide active figure correction, but do not define the mirror position. A set of six locating actuators (hardpoints) arranged in a hexapod fashion serve to locate the mirror. The stringent dynamic requirements demand that the force actuators must be able to counteract in real time for dynamic forces on the hardpoints during slewing to prevent excessive hardpoint loads. The support actuators must also maintain the prescribed forces accurately during tracking to maintain acceptable mirror figure. To meet these requirements, candidate pneumatic cylinders incorporating force feedback control and high speed servo valves are being tested using custom instrumentation with automatic data recording. Comparative charts are produced showing details of friction, hysteresis cycles, operating bandwidth, and temperature dependency. Extremely low power actuator controllers are being developed to avoid heat dissipation in critical portions of the mirror and also to allow for increased control capabilities at the actuator level, thus improving safety, performance, and the flexibility of the support system.

The influence of periodic wind turbine noise on infrasound array measurements

NASA Astrophysics Data System (ADS)

Pilger, Christoph; Ceranna, Lars

2017-02-01

Aerodynamic noise emissions from the continuously growing number of wind turbines in Germany are creating increasing problems for infrasound recording systems. These systems are equipped with highly sensitive micro pressure sensors accurately measuring acoustic signals in a frequency range inaudible to the human ear. Ten years of data (2006-2015) from the infrasound array IGADE in Northern Germany are analysed to quantify the influence of wind turbine noise on infrasound recordings. Furthermore, a theoretical model is derived and validated by a field experiment with mobile micro-barometer stations. Fieldwork was carried out 2004 to measure the infrasonic pressure level of a single horizontal-axis wind turbine and to extrapolate the sound effect for a larger number of nearby wind turbines. The model estimates the generated sound pressure level of wind turbines and thus enables for specifying the minimum allowable distance between wind turbines and infrasound stations for undisturbed recording. This aspect is particularly important to guarantee the monitoring performance of the German infrasound stations I26DE in the Bavarian Forest and I27DE in Antarctica. These stations are part of the International Monitoring System (IMS) verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), and thus have to meet stringent specifications with respect to infrasonic background noise.

Pathways to low-cost electrochemical energy storage: a comparison of aqueous and nonaqueous flow batteries

DOE PAGES

Darling, Robert M.; Gallagher, Kevin G.; Kowalski, Jeffrey A.; ...

2014-11-01

Energy storage is increasingly seen as a valuable asset for electricity grids composed of high fractions of intermittent sources, such as wind power or, in developing economies, unreliable generation and transmission services. However, the potential of batteries to meet the stringent cost and durability requirements for grid applications is largely unquantified. We investigate electrochemical systems capable of economically storing energy for hours and present an analysis of the relationships among technological performance characteristics, component cost factors, and system price for established and conceptual aqueous and nonaqueous batteries. We identified potential advantages of nonaqueous flow batteries over those based on aqueousmore » electrolytes; however, new challenging constraints burden the nonaqueous approach, including the solubility of the active material in the electrolyte. Requirements in harmony with economically effective energy storage are derived for aqueous and nonaqueous systems. The attributes of flow batteries are compared to those of aqueous and nonaqueous enclosed and hybrid (semi-flow) batteries. Flow batteries are a promising technology for reaching these challenging energy storage targets owing to their independent power and energy scaling, reliance on facile and reversible reactants, and potentially simpler manufacture as compared to established enclosed batteries such as lead–acid or lithium-ion.« less

Finger impedance evaluation by means of hand exoskeleton.

PubMed

Fiorilla, Angelo Emanuele; Nori, Francesco; Masia, Lorenzo; Sandini, Giulio

2011-12-01

Modulation of arm mechanical impedance is a fundamental aspect for interaction with the external environment and its regulation is essential for stability preservation during manipulation. Even though past research on human arm movements has suggested that models of human finger impedance would benefit the study of neural control mechanisms and the design of novel hand prostheses, relatively few studies have focused on finger and hand impedance. This article touches on the two main aspects of this research topic: first it introduces a mechanical refinement of a device that can be used to effectively measure finger impedance during manipulation tasks; then, it describes a pilot study aimed at identifying the inertia of the finger and the viscous and elastic properties of finger muscles. The proposed wearable exoskeleton, which has been designed to measure finger posture and impedance modulation while leaving the palm free, is capable of applying fast displacements while monitoring the interaction forces between the human finger and the robotic links. Moreover, due to the relatively small inertia of the fingers, it allows us to meet some stringent specifications, performing relatively large displacements (~45°) before the stretch reflex intervenes (~25 ms). The results of measurements on five subjects show that inertia, damping, and stiffness can be effectively identified and that the parameters obtained are comparable with values from previous studies.

High-throughput electrical characterization for robust overlay lithography control

NASA Astrophysics Data System (ADS)

Devender, Devender; Shen, Xumin; Duggan, Mark; Singh, Sunil; Rullan, Jonathan; Choo, Jae; Mehta, Sohan; Tang, Teck Jung; Reidy, Sean; Holt, Jonathan; Kim, Hyung Woo; Fox, Robert; Sohn, D. K.

2017-03-01

Realizing sensitive, high throughput and robust overlay measurement is a challenge in current 14nm and advanced upcoming nodes with transition to 300mm and upcoming 450mm semiconductor manufacturing, where slight deviation in overlay has significant impact on reliability and yield1). Exponentially increasing number of critical masks in multi-patterning lithoetch, litho-etch (LELE) and subsequent LELELE semiconductor processes require even tighter overlay specification2). Here, we discuss limitations of current image- and diffraction- based overlay measurement techniques to meet these stringent processing requirements due to sensitivity, throughput and low contrast3). We demonstrate a new electrical measurement based technique where resistance is measured for a macro with intentional misalignment between two layers. Overlay is quantified by a parabolic fitting model to resistance where minima and inflection points are extracted to characterize overlay control and process window, respectively. Analyses using transmission electron microscopy show good correlation between actual overlay performance and overlay obtained from fitting. Additionally, excellent correlation of overlay from electrical measurements to existing image- and diffraction- based techniques is found. We also discuss challenges of integrating electrical measurement based approach in semiconductor manufacturing from Back End of Line (BEOL) perspective. Our findings open up a new pathway for accessing simultaneous overlay as well as process window and margins from a robust, high throughput and electrical measurement approach.

Toward a Dynamically Reconfigurable Computing and Communication System for Small Spacecraft

NASA Technical Reports Server (NTRS)

Kifle, Muli; Andro, Monty; Tran, Quang K.; Fujikawa, Gene; Chu, Pong P.

2003-01-01

Future science missions will require the use of multiple spacecraft with multiple sensor nodes autonomously responding and adapting to a dynamically changing space environment. The acquisition of random scientific events will require rapidly changing network topologies, distributed processing power, and a dynamic resource management strategy. Optimum utilization and configuration of spacecraft communications and navigation resources will be critical in meeting the demand of these stringent mission requirements. There are two important trends to follow with respect to NASA's (National Aeronautics and Space Administration) future scientific missions: the use of multiple satellite systems and the development of an integrated space communications network. Reconfigurable computing and communication systems may enable versatile adaptation of a spacecraft system's resources by dynamic allocation of the processor hardware to perform new operations or to maintain functionality due to malfunctions or hardware faults. Advancements in FPGA (Field Programmable Gate Array) technology make it possible to incorporate major communication and network functionalities in FPGA chips and provide the basis for a dynamically reconfigurable communication system. Advantages of higher computation speeds and accuracy are envisioned with tremendous hardware flexibility to ensure maximum survivability of future science mission spacecraft. This paper discusses the requirements, enabling technologies, and challenges associated with dynamically reconfigurable space communications systems.

Effect of reductive treatments on Pt behavior and NOx storage in lean NOx trap catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xianqin; Kim, Do Heui; Kwak, Ja Hun

2011-10-01

Lean NOx trap (LNT) catalysts represent a promising approach to meet increasingly stringent NOx emission regulations on diesel and other lean-burn engines. Pt material properties, including dispersion and particle size, are known to be important factors in determining NOx uptake performance, since Pt provides active sites for NO oxidation to NO2 necessary for storing NOx as nitrates, and for the reduction of nitrates to N2. In this work, the physicochemical properties of Pt in Pt-BaO/Al2O3 LNT catalysts, such as the Pt accessible surface area and particle size, were investigated by using various tools, such as irreversible volumetric H2 chemisorption, highmore » resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD), following successive reductive treatments at elevated temperatures. NOx uptake activities were also measured to establish a relationship between the properties of Pt and NOx storage following identical high-temperature reductive treatments. We find that the reductive treatments of Pt-BaO/Al2O3 lean NOx trap catalysts at temperatures up to 500 ºC promote a significant increase in NOx uptake explained, in part, by an induced close interaction between Pt and BaO phases in the catalyst, thus enabling facilitation of the NOx storage process.« less

Safe water supply without disinfection in a large city case study: Berlin.

PubMed

Grohmann, A; Petersohn, D

2000-01-01

Berlin's water supplies originate exclusively from groundwater. For sustainable water management, river water is treated by flocculation and filtration and used either for artificial groundwater recharge (rivers Spree and Havel) or for bank filtration (Nordgraben and Lake Tegel). Drinking water chlorination was abandoned in Berlin (West) in 1978, and in Berlin (East) in 1992, following German unification. Chlorine consumption for the purpose of weekly performance checks in the chlorination plants of Berlin's 11 waterworks and occasional chlorination within the pipe system following pipe burst events amounts to 2500 kg per year. Based on the annual water demand of 250 million cubic metres, this is equivalent to 0.01 mg of chlorine per litre. Microbiological monitoring at the 11 waterworks and at 383 sampling points within the pipe system shows CFU at less than 10/1 ml-1 and coliforms and E. coli invariably at 0/100 ml-1. In view of the low AOX content, a multiplication of bacteria within the pipe system can be expected to occur not at all or only to a small extent. Resource protection measures, filter backwashing and pipe system maintenance in observance of the relevant technical rules will continue to ensure that the quality of Berlin's drinking water meets stringent hygiene requirements without chlorination.

Circuitry Linking the Csr and Stringent Response Global Regulatory Systems

PubMed Central

Edwards, Adrianne N.; Patterson-Fortin, Laura M.; Vakulskas, Christopher A.; Mercante, Jeffrey W.; Potrykus, Katarzyna; Vinella, Daniel; Camacho, Martha I.; Fields, Joshua A.; Thompson, Stuart A.; Georgellis, Dimitris; Cashel, Michael; Babitzke, Paul; Romeo, Tony

2011-01-01

Summary CsrA protein regulates important cellular processes by binding to target mRNAs and altering their translation and/or stability. In Escherichia coli, CsrA binds to sRNAs, CsrB and CsrC, which sequester CsrA and antagonize its activity. Here, mRNAs for relA, spoT and dksA of the stringent response system were found among 721 different transcripts that copurified with CsrA. Many of the transcripts that copurified with CsrA were previously determined to respond to ppGpp and/or DksA. We examined multiple regulatory interactions between the Csr and stringent response systems. Most importantly, DksA and ppGpp robustly activated csrB/C transcription (10-fold), while they modestly activated csrA expression. We propose that CsrA-mediated regulation is relieved during the stringent response. Gel shift assays confirmed high affinity binding of CsrA to relA mRNA leader and weaker interactions with dksA and spoT. Reporter fusions, qRT-PCR, and immunoblotting showed that CsrA repressed relA expression, and (p)ppGpp accumulation during stringent response was enhanced in a csrA mutant. CsrA had modest to negligible effects on dksA and spoT expression. Transcription of dksA was negatively autoregulated via a feedback loop that tended to mask CsrA effects. We propose that the Csr system fine-tunes the stringent response and discuss biological implications of the composite circuitry. PMID:21488981

Rugged, Tunable Extended-Cavity Diode Laser

NASA Technical Reports Server (NTRS)

Moore, Donald; Brinza, David; Seidel, David; Klipstein, William; Choi, Dong Ho; Le, Lam; Zhang, Guangzhi; Iniguez, Roberto; Tang, Wade

2007-01-01

A rugged, tunable extended-cavity diode laser (ECDL) has been developed to satisfy stringent requirements for frequency stability, notably including low sensitivity to vibration. This laser is designed specifically for use in an atomic-clock experiment to be performed aboard the International Space Station (ISS). Lasers of similar design would be suitable for use in terrestrial laboratories engaged in atomic-clock and atomic-physics research.

Dummy and injury criteria for aircraft crashworthiness.

DOT National Transportation Integrated Search

1996-04-01

Since 1988, newly type-certificated aircraft are required to comply with stringent crashworthiness requirements. Central to these more stringent requirements is a dynamic test that assesses the potential for injury for someone exposed to similar cond...

Final Report of a CRADA Between Pacific Northwest National Laboratory and the Ford Motor Company (CRADA No. PNNL/265): “Deactivation Mechanisms of Base Metal/Zeolite Urea Selective Catalytic Reduction Materials, and Development of Zeolite-Based Hydrocarbon Adsorber Materials”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Feng; Kwak, Ja Hun; Lee, Jong H.

2013-02-14

Reducing NOx emissions and particulate matter (PM) are primary concerns for diesel vehicles required to meet current LEV II and future LEV III emission standards which require 90+% NOx conversion. Currently, urea SCR as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) are being used for emission control system components by Ford Motor Company for 2010 and beyond diesel vehicles. Because the use of this technology for vehicle applications is new, the relative lack of experience makes it especially challenging to satisfy durability requirements. Of particular concern is being able to realistically simulate actual field aging of themore » catalyst systems under laboratory conditions. This is necessary both as a rapid assessment tool for verifying improved performance and certifiability of new catalyst formulations, and to develop a good understanding of deactivation mechanisms that can be used to develop improved catalyst materials. In addition to NOx and PM, the hydrocarbon (HC) emission standards are expected to become much more stringent during the next few years. Meanwhile, the engine-out HC emissions are expected to increase and/or be more difficult to remove. Since HC can be removed only when the catalyst becomes warm enough for its oxidation, three-way catalyst (TWC) and diesel oxidation catalyst (DOC) formulations often contain proprietary zeolite materials to hold the HC produced during the cold start period until the catalyst reaches its operating temperature (e.g., >200°C). Unfortunately, much of trapped HC tends to be released before the catalyst reaches the operating temperature. Among materials effective for trapping HC during the catalyst warm-up period, siliceous zeolites are commonly used because of their high surface area and high stability under typical operating conditions. However, there has been little research on the physical properties of these materials related to the adsorption and release of various hydrocarbon species found in the engine exhaust. For these reasons, automakers and engine manufacturers have difficulty improving their catalytic converters for meeting the stringent HC emission standards. In this collaborative program, scientists and engineers in the Institute for Integrated Catalysis at Pacific Northwest National Laboratory and at Ford Motor Company have investigated laboratory- and engine-aged SCR catalysts, containing mainly base metal zeolites. These studies are leading to a better understanding of various aging factors that impact the long-term performance of SCR catalysts and improve the correlation between laboratory and engine aging, saving experimental time and cost. We have also studied materials effective for the temporary storage of HC species during the cold-start period. In particular, we have examined the adsorption and desorption of various HC species produced during the combustion with different fuels (e.g., gasoline, E85, diesel) over potential HC adsorber materials, and measured the kinetic parameters to update Ford’s HC adsorption model. Since this CRADA has now been completed, in this final report we will provide brief summaries of most of the work carried out on this CRADA over the last several years.« less

Enhanced Communication Network Solution for Positive Train Control Implementation

NASA Technical Reports Server (NTRS)

Fatehi, M. T.; Simon, J.; Chang, W.; Chow, E. T.; Burleigh, S. C.

2011-01-01

The commuter and freight railroad industry is required to implement Positive Train Control (PTC) by 2015 (2012 for Metrolink), a challenging network communications problem. This paper will discuss present technologies developed by the National Aeronautics and Space Administration (NASA) to overcome comparable communication challenges encountered in deep space mission operations. PTC will be based on a new cellular wireless packet Internet Protocol (IP) network. However, ensuring reliability in such a network is difficult due to the "dead zones" and transient disruptions we commonly experience when we lose calls in commercial cellular networks. These disruptions make it difficult to meet PTC s stringent reliability (99.999%) and safety requirements, deployment deadlines, and budget. This paper proposes innovative solutions based on space-proven technologies that would help meet these challenges: (1) Delay Tolerant Networking (DTN) technology, designed for use in resource-constrained, embedded systems and currently in use on the International Space Station, enables reliable communication over networks in which timely data acknowledgments might not be possible due to transient link outages. (2) Policy-Based Management (PBM) provides dynamic management capabilities, allowing vital data to be exchanged selectively (with priority) by utilizing alternative communication resources. The resulting network may help railroads implement PTC faster, cheaper, and more reliably.

Analysis of QoS Requirements for e-Health Services and Mapping to Evolved Packet System QoS Classes

PubMed Central

Skorin-Kapov, Lea; Matijasevic, Maja

2010-01-01

E-Health services comprise a broad range of healthcare services delivered by using information and communication technology. In order to support existing as well as emerging e-Health services over converged next generation network (NGN) architectures, there is a need for network QoS control mechanisms that meet the often stringent requirements of such services. In this paper, we evaluate the QoS support for e-Health services in the context of the Evolved Packet System (EPS), specified by the Third Generation Partnership Project (3GPP) as a multi-access all-IP NGN. We classify heterogeneous e-Health services based on context and network QoS requirements and propose a mapping to existing 3GPP QoS Class Identifiers (QCIs) that serve as a basis for the class-based QoS concept of the EPS. The proposed mapping aims to provide network operators with guidelines for meeting heterogeneous e-Health service requirements. As an example, we present the QoS requirements for a prototype e-Health service supporting tele-consultation between a patient and a doctor and illustrate the use of the proposed mapping to QCIs in standardized QoS control procedures. PMID:20976301

Compression Ignition Engines – Revolutionary Technology That has Civilized Frontiers all Over the Globe from the Industrial Revolution into the Twenty-First Century

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciatti, Stephen A.

The history, present and future of the compression ignition engine is a fascinating story that spans over 100 years, from the time of Rudolf Diesel to the highly regulated and computerized engines of the 21st Century. The development of these engines provided inexpensive, reliable and high power density machines to allow transportation, construction and farming to be more productive with less human effort than in any previous period of human history. The concept that fuels could be consumed efficiently and effectively with only the ignition of pressurized and heated air was a significant departure from the previous coal-burning architecture ofmore » the 1800s. Today, the compression ignition engine is undergoing yet another revolution. The equipment that provides transport, builds roads and infrastructure, and harvests the food we eat needs to meet more stringent requirements than ever before. How successfully 21st Century engineers are able to make compression ignition engine technology meet these demands will be of major influence in assisting developing nations (with over 50% of the world’s population) achieve the economic and environmental goals they seek.« less

Ka-band monopulse antenna-pointing systems analysis and simulation

NASA Technical Reports Server (NTRS)

Lo, V. Y.

1996-01-01

NASA 's Deep Space Network (DSN) has been using both 70-m and 34-m reflector antennas to communicate with spacecraft at S-band (2.3 GHz) and X-band (8.45 GHz). To improve the quality of telecommunication and to meet future mission requirements, JPL has been developing 34-m Ka-band (32-GHz) beam waveguide antennas. Presently, antenna pointing operates in either the open-loop mode with blind pointing using navigation predicts or the closed-loop mode with conical scan (conscan). Pointing accuracy under normal conscan operating conditions is in the neighborhood of 5 mdeg. This is acceptable at S- and X-bands, but not enough at Ka-band. Due to the narrow beamwidth at Ka-band, it is important to improve pointing accuracy significantly (approximately 2 mdeg). Monopulse antenna tracking is one scheme being developed to meet the stringent pointing-accuracy requirement at Ka-band. Other advantages of monopulse tracking include low sensitivity to signal amplitude fluctuations as well as single-pulse processing for acquisition and tracking. This article presents system modeling, signal processing, simulation, and implementation of Ka-band monopulse tracking feed for antennas in NASA/DSN ground stations.

Circuitry linking the Csr and stringent response global regulatory systems.

PubMed

Edwards, Adrianne N; Patterson-Fortin, Laura M; Vakulskas, Christopher A; Mercante, Jeffrey W; Potrykus, Katarzyna; Vinella, Daniel; Camacho, Martha I; Fields, Joshua A; Thompson, Stuart A; Georgellis, Dimitris; Cashel, Michael; Babitzke, Paul; Romeo, Tony

2011-06-01

CsrA protein regulates important cellular processes by binding to target mRNAs and altering their translation and/or stability. In Escherichia coli, CsrA binds to sRNAs, CsrB and CsrC, which sequester CsrA and antagonize its activity. Here, mRNAs for relA, spoT and dksA of the stringent response system were found among 721 different transcripts that copurified with CsrA. Many of the transcripts that copurified with CsrA were previously determined to respond to ppGpp and/or DksA. We examined multiple regulatory interactions between the Csr and stringent response systems. Most importantly, DksA and ppGpp robustly activated csrB/C transcription (10-fold), while they modestly activated csrA expression. We propose that CsrA-mediated regulation is relieved during the stringent response. Gel shift assays confirmed high affinity binding of CsrA to relA mRNA leader and weaker interactions with dksA and spoT. Reporter fusions, qRT-PCR and immunoblotting showed that CsrA repressed relA expression, and (p)ppGpp accumulation during stringent response was enhanced in a csrA mutant. CsrA had modest to negligible effects on dksA and spoT expression. Transcription of dksA was negatively autoregulated via a feedback loop that tended to mask CsrA effects. We propose that the Csr system fine-tunes the stringent response and discuss biological implications of the composite circuitry. © Published 2011. This article is a US Government work and is in the public domain in the USA.

Design Tools for Cost-Effective Implementation of Planetary Protection Requirements

NASA Technical Reports Server (NTRS)

Hamlin, Louise; Belz, Andrea; Evans, Michael; Kastner, Jason; Satter, Celeste; Spry, Andy

2006-01-01

Since the Viking missions to Mars in the 1970s, accounting for the costs associated with planetary protection implementation has not been done systematically during early project formulation phases, leading to unanticipated costs during subsequent implementation phases of flight projects. The simultaneous development of more stringent planetary protection requirements, resulting from new knowledge about the limits of life on Earth, together with current plans to conduct life-detection experiments on a number of different solar system target bodies motivates a systematic approach to integrating planetary protection requirements and mission design. A current development effort at NASA's Jet Propulsion Laboratory is aimed at integrating planetary protection requirements more fully into the early phases of mission architecture formulation and at developing tools to more rigorously predict associated cost and schedule impacts of architecture options chosen to meet planetary protection requirements.

Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design

NASA Technical Reports Server (NTRS)

Runkle, R. E.; Drobnik, R. F.

1979-01-01

The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

Design and Error Analysis of a Vehicular AR System with Auto-Harmonization.

PubMed

Foxlin, Eric; Calloway, Thomas; Zhang, Hongsheng

2015-12-01

This paper describes the design, development and testing of an AR system that was developed for aerospace and ground vehicles to meet stringent accuracy and robustness requirements. The system uses an optical see-through HMD, and thus requires extremely low latency, high tracking accuracy and precision alignment and calibration of all subsystems in order to avoid mis-registration and "swim". The paper focuses on the optical/inertial hybrid tracking system and describes novel solutions to the challenges with the optics, algorithms, synchronization, and alignment with the vehicle and HMD systems. Tracker accuracy is presented with simulation results to predict the registration accuracy. A car test is used to create a through-the-eyepiece video demonstrating well-registered augmentations of the road and nearby structures while driving. Finally, a detailed covariance analysis of AR registration error is derived.

Achieving Vibration Stability of the NSLS-II Hard X-ray Nanoprobe Beamline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simos, N.; Chu, Y. N.; Broadbent, A.

2010-08-30

The Hard X-ray Nanoprobe (HXN) Beamline of National Synchrotron Light Source II (NSLS-lI) requires high levels of stability in order to achieve the desired instrument resolution. To ensure that the design of the endstation helps meet the stringent criteria and that natural and cultural vibration is mitigated both passively and actively, a comprehensive study complimentary to the design process has been undertaken. Vibration sources that have the potential to disrupt sensitive experiments such as wind, traffic and NSLS II operating systems have been studied using state of the art simulations and an array of field data. Further, final stage vibrationmore » isolation principles have been explored in order to be utilized in supporting endstation instruments. This paper presents results of the various study aspects and their influence on the HXN design optimization.« less

Multilevel DC Link Inverter for Brushless Permanent Magnet Motors with Very Low Inductance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, G.J.

2001-10-29

Due to their long effective air gaps, permanent magnet motors tend to have low inductance. The use of ironless stator structure in present high power PM motors (several tens of kWs) reduces the inductance even further (< 100 {micro}H). This low inductance imposes stringent current regulation demands for the inverter to obtain acceptable current ripple. An analysis of the current ripple for these low inductance brushless PM motors shows that a standard inverter with the most commonly used IGBT switching devices cannot meet the current regulation demands and will produce unacceptable current ripples due to the IGBT's limited switching frequency.more » This paper introduces a new multilevel dc link inverter, which can dramatically reduce the current ripple for brushless PM motor drives. The operating principle and design guidelines are included.« less

The Orbital Design of Alpha Centauri Exoplanet Satellite (ACESat)

NASA Technical Reports Server (NTRS)

Weston, Sasha; Belikov, Rus; Bendek, Eduardo

2015-01-01

Exoplanet candidates discovered by Kepler are too distant for biomarkers to be detected with foreseeable technology. Alpha Centauri has high separation from other stars and is of close proximity to Earth, which makes the binary star system 'low hanging fruit' for scientists. Alpha Centauri Exoplanet Satellite (ACESat) is a mission proposed to Small Explorer Program (SMEX) that will use a coronagraph to search for an orbiting planet around one of the stars of Alpha Centauri. The trajectory design for this mission is presented here where three different trajectories are considered: Low Earth Orbit (LEO), Geosynchronous Orbit (GEO) and a Heliocentric Orbit. Uninterrupted stare time to Alpha Centauri is desirable for meeting science requirements, or an orbit that provides 90% stare time to the science target. The instrument thermal stability also has stringent requirements for proper function, influencing trajectory design.

Multicolour synthesis in lanthanide-doped nanocrystals through cation exchange in water

NASA Astrophysics Data System (ADS)

Han, Sanyang; Qin, Xian; An, Zhongfu; Zhu, Yihan; Liang, Liangliang; Han, Yu; Huang, Wei; Liu, Xiaogang

2016-10-01

Meeting the high demand for lanthanide-doped luminescent nanocrystals across a broad range of fields hinges upon the development of a robust synthetic protocol that provides rapid, just-in-time nanocrystal preparation. However, to date, almost all lanthanide-doped luminescent nanomaterials have relied on direct synthesis requiring stringent controls over crystal nucleation and growth at elevated temperatures. Here we demonstrate the use of a cation exchange strategy for expeditiously accessing large classes of such nanocrystals. By combining the process of cation exchange with energy migration, the luminescence properties of the nanocrystals can be easily tuned while preserving the size, morphology and crystal phase of the initial nanocrystal template. This post-synthesis strategy enables us to achieve upconversion luminescence in Ce3+ and Mn2+-activated hexagonal-phased nanocrystals, opening a gateway towards applications ranging from chemical sensing to anti-counterfeiting.

Design, fabrication, and test of a Graphite/Epoxy Metering Shell (GEMS). [for the large space telescope

NASA Technical Reports Server (NTRS)

1975-01-01

A program to design, fabricate and test a dimensionally stable metering structure in support of the large space telescope (LST) program is discussed. Graphite/epoxy was the material selected as the only viable candidate material which can meet the stringent thermal expansion criteria of the LST. A metering shell was designed and fabricated, with emphasis on dimensional stability in conjunction with low cost. Thermal expansion test coupons extracted from the layups of the skin panels indicated the attainment of a coefficient of thermal expansion of 0.0666 micrometers/m K. Subsequent thermal vacuum chamber tests on the complete metering shell demonstrated an expansion of the 2.95-meter overall length of 0.27 micrometers/K. Static and dynamics tests, which demonstrated adequacy with respect to limit loads and stiffness, were also accomplished.

SCDU (Spectral Calibration Development Unit) Testbed Narrow Angle Astrometric Performance

NASA Technical Reports Server (NTRS)

Wang, Xu; Goullioud, Renaud; Nemati, Bijan; Shao, Michael; Wehmeier, Udo J.; Weilert, Mark A.; Werne, Thomas A.; Wu, Janet P.; Zhai, Chengxing

2010-01-01

The most stringent astrometric performance requirements on NASA's SIM(Space Interferometer Mission)-Lite mission will come from the so-called Narrow-Angle (NA) observing scenario, aimed at finding Earth-like exoplanets, where the interferometer chops between the target star and several nearby reference stars multiple times over the course of a single visit. Previously, about 20 pm NA error with various shifts was reported. Since then, investigation has been under way to understand the mechanisms that give rise to these shifts. In this paper we report our findings, the adopted mitigation strategies, and the resulting testbed performance.

Integrated Analysis of Greenhouse Gas Mitigation Options and Related Impacts

EPA Science Inventory

Increased concerns over air pollution (combined with detrimental health effects) and climate change have called for more stringent emission reduction strategies for criteria air pollutants and greenhouse gas emissions. However, stringent regulatory policies can possibly have a...

A Cross-Cancer Genetic Association Analysis of the DNA Repair and DNA Damage Signaling Pathways for Lung, Ovary, Prostate, Breast, and Colorectal Cancer.

PubMed

Scarbrough, Peter M; Weber, Rachel Palmieri; Iversen, Edwin S; Brhane, Yonathan; Amos, Christopher I; Kraft, Peter; Hung, Rayjean J; Sellers, Thomas A; Witte, John S; Pharoah, Paul; Henderson, Brian E; Gruber, Stephen B; Hunter, David J; Garber, Judy E; Joshi, Amit D; McDonnell, Kevin; Easton, Doug F; Eeles, Ros; Kote-Jarai, Zsofia; Muir, Kenneth; Doherty, Jennifer A; Schildkraut, Joellen M

2016-01-01

DNA damage is an established mediator of carcinogenesis, although genome-wide association studies (GWAS) have identified few significant loci. This cross-cancer site, pooled analysis was performed to increase the power to detect common variants of DNA repair genes associated with cancer susceptibility. We conducted a cross-cancer analysis of 60,297 single nucleotide polymorphisms, at 229 DNA repair gene regions, using data from the NCI Genetic Associations and Mechanisms in Oncology (GAME-ON) Network. Our analysis included data from 32 GWAS and 48,734 controls and 51,537 cases across five cancer sites (breast, colon, lung, ovary, and prostate). Because of the unavailability of individual data, data were analyzed at the aggregate level. Meta-analysis was performed using the Association analysis for SubSETs (ASSET) software. To test for genetic associations that might escape individual variant testing due to small effect sizes, pathway analysis of eight DNA repair pathways was performed using hierarchical modeling. We identified three susceptibility DNA repair genes, RAD51B (P < 5.09 × 10(-6)), MSH5 (P < 5.09 × 10(-6)), and BRCA2 (P = 5.70 × 10(-6)). Hierarchical modeling identified several pleiotropic associations with cancer risk in the base excision repair, nucleotide excision repair, mismatch repair, and homologous recombination pathways. Only three susceptibility loci were identified, which had all been previously reported. In contrast, hierarchical modeling identified several pleiotropic cancer risk associations in key DNA repair pathways. Results suggest that many common variants in DNA repair genes are likely associated with cancer susceptibility through small effect sizes that do not meet stringent significance testing criteria. ©2015 American Association for Cancer Research.

Multi-objective Optimization for the Robust Performance of Drinking Water Treatment Plants under Climate Change and Climate Extremes

NASA Astrophysics Data System (ADS)

Raseman, W. J.; Kasprzyk, J. R.; Rosario-Ortiz, F.; Summers, R. S.; Stewart, J.; Livneh, B.

2016-12-01

To promote public health, the United States Environmental Protection Agency (US EPA), and similar entities around the world enact strict laws to regulate drinking water quality. These laws, such as the Stage 1 and 2 Disinfectants and Disinfection Byproducts (D/DBP) Rules, come at a cost to water treatment plants (WTPs) which must alter their operations and designs to meet more stringent standards and the regulation of new contaminants of concern. Moreover, external factors such as changing influent water quality due to climate extremes and climate change, may force WTPs to adapt their treatment methods. To grapple with these issues, decision support systems (DSSs) have been developed to aid WTP operation and planning. However, there is a critical need to better address long-term decision making for WTPs. In this poster, we propose a DSS framework for WTPs for long-term planning, which improves upon the current treatment of deep uncertainties within the overall potable water system including the impact of climate on influent water quality and uncertainties in treatment process efficiencies. We present preliminary results exploring how a multi-objective evolutionary algorithm (MOEA) search can be coupled with models of WTP processes to identify high-performing plans for their design and operation. This coupled simulation-optimization technique uses Borg MOEA, an auto-adaptive algorithm, and the Water Treatment Plant Model, a simulation model developed by the US EPA to assist in creating the D/DBP Rules. Additionally, Monte Carlo sampling methods were used to study the impact of uncertainty of influent water quality on WTP decision-making and generate plans for robust WTP performance.

Competency to consent to medical treatment in cognitively impaired patients with Parkinson's disease.

PubMed

Dymek, M P; Atchison, P; Harrell, L; Marson, D C

2001-01-09

To investigate capacity to consent to medical treatment (competency) in cognitively impaired patients with PD. Although competency has been studied empirically in patients with cortical dementia (AD), no empirical studies have examined competency in patients with PD or other subcortical neurodegenerative disorders. Patients with PD with cognitive impairment (n = 20) and older controls (n = 20) were compared using a standardized competency measure (Capacity to Consent to Treatment Instrument [CCTI]) and neuropsychological test measures. The CCTI tests competency performance and assigns outcomes (capable, marginally capable, incapable) under four different legal standards (LS). Patients with PD performed below controls on the four LS: capacity to evidence a treatment choice (LS1) (p < 0.03), capacity to appreciate consequences of a treatment choice (LS3) (p < 0.03), capacity to provide rational reasons for a treatment choice (LS4) (p < 0.0001), and capacity to understand the treatment situation and choices (LS5) (p < 0.0001). With respect to competency outcomes, patients with PD demonstrated increasing compromise (marginally capable or incapable outcomes) across the four standards: LS1 (25%), LS3 (45%), LS4 (55%), and LS5 (80%). In the PD group, simple measures of executive function (the Executive Interview) and to a lesser extent memory/orientation (Dementia Rating Scale, Memory subscale) were key predictors of competency performance and outcome on the LS. Cognitively impaired patients with PD are likely to have impaired consent capacity, and are at risk of losing competency over the course of their neurodegenerative illness. Patients with PD have particular difficulty meeting more stringent, clinically relevant competency standards that tap reasoning skills and comprehension of treatment information. Executive dysfunction appears to be a primary neurocognitive mechanism for competency loss in PD.

Implementation of fast handover for proxy mobile IPv6: Resolving out-of-order packets

PubMed Central

Anh, Khuong Quoc; Choo, Hyunseung

2017-01-01

Mobile IP allows for location-independent routing of IP datagrams on the Internet. Mobile IP specifies how a mobile node (MN) registers with its home agent and how the home agent routes datagrams to the MN through the tunnel. Current Mobile IP protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. Fast handover for Proxy Mobile IPv6 (FPMIPv6) is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6) protocol. However, while implementing the FPMIPv6 scheme in a testbed, we encounter the out-of-order packet (OoOP) problem. The cause of this problem is the existence of two paths for data transmitted from a correspondent node (CN) to an MN. Since the problem affects the quality of service (QoS) of the network and the performance of the MN, we propose a new scheme using the last packet marker and packet buffering to solve this problem in FPMIPv6. The new Mobile Access Gateway (MAG) can control and deliver the data transmitted via the old path or the new path to an MN in order, using the last packet marker to notify the end of the data delivery in the old path and the packet buffering for holding the data delivered in the new path. We implement both the proposed scheme and FPMIPv6 in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. A performance evaluation reveals that the proposed scheme can handle the OoOP problem efficiently. PMID:28968450

Implementation of fast handover for proxy mobile IPv6: Resolving out-of-order packets.

PubMed

Kang, Byungseok; Anh, Khuong Quoc; Choo, Hyunseung

2017-01-01

Mobile IP allows for location-independent routing of IP datagrams on the Internet. Mobile IP specifies how a mobile node (MN) registers with its home agent and how the home agent routes datagrams to the MN through the tunnel. Current Mobile IP protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. Fast handover for Proxy Mobile IPv6 (FPMIPv6) is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6) protocol. However, while implementing the FPMIPv6 scheme in a testbed, we encounter the out-of-order packet (OoOP) problem. The cause of this problem is the existence of two paths for data transmitted from a correspondent node (CN) to an MN. Since the problem affects the quality of service (QoS) of the network and the performance of the MN, we propose a new scheme using the last packet marker and packet buffering to solve this problem in FPMIPv6. The new Mobile Access Gateway (MAG) can control and deliver the data transmitted via the old path or the new path to an MN in order, using the last packet marker to notify the end of the data delivery in the old path and the packet buffering for holding the data delivered in the new path. We implement both the proposed scheme and FPMIPv6 in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. A performance evaluation reveals that the proposed scheme can handle the OoOP problem efficiently.

Multi objective multi refinery optimization with environmental and catastrophic failure effects objectives

NASA Astrophysics Data System (ADS)

Khogeer, Ahmed Sirag

2005-11-01

Petroleum refining is a capital-intensive business. With stringent environmental regulations on the processing industry and declining refining margins, political instability, increased risk of war and terrorist attacks in which refineries and fuel transportation grids may be targeted, higher pressures are exerted on refiners to optimize performance and find the best combination of feed and processes to produce salable products that meet stricter product specifications, while at the same time meeting refinery supply commitments and of course making profit. This is done through multi objective optimization. For corporate refining companies and at the national level, Intea-Refinery and Inter-Refinery optimization is the second step in optimizing the operation of the whole refining chain as a single system. Most refinery-wide optimization methods do not cover multiple objectives such as minimizing environmental impact, avoiding catastrophic failures, or enhancing product spec upgrade effects. This work starts by carrying out a refinery-wide, single objective optimization, and then moves to multi objective-single refinery optimization. The last step is multi objective-multi refinery optimization, the objectives of which are analysis of the effects of economic, environmental, product spec, strategic, and catastrophic failure. Simulation runs were carried out using both MATLAB and ASPEN PIMS utilizing nonlinear techniques to solve the optimization problem. The results addressed the need to debottleneck some refineries or transportation media in order to meet the demand for essential products under partial or total failure scenarios. They also addressed how importing some high spec products can help recover some of the losses and what is needed in order to accomplish this. In addition, the results showed nonlinear relations among local and global objectives for some refineries. The results demonstrate that refineries can have a local multi objective optimum that does not follow the same trends as either global or local single objective optimums. Catastrophic failure effects on refinery operations and on local objectives are more significant than environmental objective effects, and changes in the capacity or the local objectives follow a discrete behavioral pattern, in contrast to environmental objective cases in which the effects are smoother. (Abstract shortened by UMI.)

SUSY searches at the LHC with the ATLAS experiment

ScienceCinema

D' Onofrio, Monica

2017-12-18

First ATLAS searches for signals of Supersymmetry in proton-proton collisions at the LHC are presented. These searches are performed in various channels containing different lepton and jet multiplicities in the final states; the full data sample recorded in the 2010 LHC run, corresponding to an integrated luminosity of 35 pb-1, has been analysed. Limits on squarks and gluins are the most stringent to date.

Universal Industrial Solution and Industrial Sectors Module for Pulp and Paper Sector

EPA Science Inventory

Increased concerns over air pollution and its detrimental effects on health have called for more stringent emission reduction strategies in the industrial sector. However, stringent regulatory policies can potentially adversely affect domestic and international trade. Therefore E...

Occurrence of the regulatory nucleotides ppGpp and pppGpp following induction of the stringent response in staphylococci.

PubMed Central

Cassels, R; Oliva, B; Knowles, D

1995-01-01

The stringent response in Escherichia coli and many other organisms is regulated by the nucleotides ppGpp and pppGpp. We show here for the first time that at least six staphylococcal species also synthesize ppGpp and pppGpp upon induction of the stringent response by mupirocin. Spots corresponding to ppGpp and pppGpp on thin-layer chromatograms suggest that pppGpp is the principal regulatory nucleotide synthesized by staphylococci in response to mupirocin, rather than ppGpp as in E. coli. PMID:7665499

The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus.

PubMed

Hood, Rachel D; Higgins, Sean A; Flamholz, Avi; Nichols, Robert J; Savage, David F

2016-08-16

The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3'-diphosphate 5'-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle.

The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus

PubMed Central

Hood, Rachel D.; Higgins, Sean A.; Flamholz, Avi; Nichols, Robert J.

2016-01-01

The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3′-diphosphate 5′-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle. PMID:27486247

Medical Device Regulation: A Comparison of the United States and the European Union.

PubMed

Maak, Travis G; Wylie, James D

2016-08-01

Medical device regulation is a controversial topic in both the United States and the European Union. Many physicians and innovators in the United States cite a restrictive US FDA regulatory process as the reason for earlier and more rapid clinical advances in Europe. The FDA approval process mandates that a device be proved efficacious compared with a control or be substantially equivalent to a predicate device, whereas the European Union approval process mandates that the device perform its intended function. Stringent, peer-reviewed safety data have not been reported. However, after recent high-profile device failures, political pressure in both the United States and the European Union has favored more restrictive approval processes. Substantial reforms of the European Union process within the next 5 to 10 years will result in a more stringent approach to device regulation, similar to that of the FDA. Changes in the FDA regulatory process have been suggested but are not imminent.

Probiotic use in at-risk populations.

PubMed

Sanders, Mary Ellen; Merenstein, Daniel J; Ouwehand, Arthur C; Reid, Gregor; Salminen, Seppo; Cabana, Michael D; Paraskevakos, George; Leyer, Gregory

To inform health care providers about quality standards for manufacture of probiotic products being recommended for at-risk patient populations. Probiotics are used in a variety of clinical settings, sometimes in at-risk populations for therapeutic endpoints. Although probiotics might not be approved as drugs, they are sometimes used for the prevention or treatment of disease. In the United States, and many regions of the world, probiotic products are marketed as dietary supplements (not drugs) and are therefore subject to different manufacturing and quality control standards than approved drugs are. Health care providers need to be assured that probiotic products used in at-risk populations are safe for this use. Pharmacists should require certificates of analysis, which document quality standards, from manufacturers of products stocked in hospital formularies or other pharmacies dispensing to at-risk people. Although responsible manufacturers use stringent quality standards on their processes and finished products, using a third party to verify compliance with manufacturing and accuracy of product labeling adds assurance to end users that the product is of high quality. It is in patients' best interest to use probiotics in the prevention and treatment of conditions when the evidence is convincing. To protect high-risk patients, probiotic products should meet stringent microbiological standards. Product testing results should be available for review before recommending probiotic products to at-risk individuals. For products used in at-risk populations, manufacturers should provide this information or participate in a third-party verification program that certifies compliance. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Digital orthoimagery base specification V1.0

USGS Publications Warehouse

Rufe, Philip P.

2014-01-01

The resolution requirement for orthoimagery in support of the The National Map of the U.S. Geological Survey (USGS) is 1 meter. However, as the Office of Management and Budget A-16 designated Federal agency responsible for base orthoimagery, the USGS National Geospatial Program (NGP) has developed this base specification to include higher resolution orthoimagery. Many Federal, State, and local programs use high-resolution orthoimagery for various purposes including critical infrastructure management, vector data updates, land-use analysis, natural resource inventory, and extraction of data. The complex nature of large-area orthoimagery datasets, combined with the broad interest in orthoimagery, which is of consistent quality and spatial accuracy, requires high-resolution orthoimagery to meet or exceed the format and content outlined in this specification. The USGS intends to use this specification primarily to create consistency across all NGP funded and managed orthoimagery collections, in particular, collections in support of the National Digital Orthoimagery Program (NDOP). In the absence of other comprehensive specifications or standards, the USGS intends that this specification will, to the highest degree practical, be adopted by other USGS programs and mission areas, and by other Federal agencies. This base specification, defining minimum parameters for orthoimagery data collection. Local conditions in any given project area, specialized applications for the data, or the preferences of cooperators, may mandate more stringent requirements. The USGS fully supports the acquisition of more detailed, accurate, or value-added data that exceed the base specification outlined herein. A partial list of common “buy-up” options is provided in appendix 1 for those areas and projects that require more stringent or expanded specifications.

The role of tramadol in pain management in Latin America: a report by the Change Pain Latin America Advisory Panel.

PubMed

Santos Garcia, Joäo Batista; Lech, Osvandré; Campos Kraychete, Durval; Rico, María Antonieta; Hernández-Castro, John Jairo; Colimon, Frantz; Guerrero, Carlos; Sempértegui Gallegos, Manuel; Lara-Solares, Argelia; Flores Cantisani, José Alberto; Amescua-Garcia, César; Guillén Núñez, María Del Rocío; Berenguel Cook, María Del Rosario; Jreige Iskandar, Aziza; Bonilla Sierra, Patricia

2017-09-01

Change Pain Latin America (CPLA) was created to enhance chronic pain understanding and develop pain management improving strategies in this region. During its seventh meeting (August 2016), the main objective was to discuss tramadol's role in treating pain in Latin America. Furthermore, potential pain management consequences were considered, if tramadol was to become more stringently controlled. Key topics discussed were: main indications for prescribing tramadol, its pharmacological characteristics, safety and tolerability, effects of restrictions on its availability and use, and consequent impact on pain care quality. The experts agreed that tramadol is used to treat a wide spectrum of non-oncological pain conditions (e.g. post-surgical, musculoskeletal, post-traumatic, neuropathic, fibromyalgia), as well as cancer pain. Its relevance when treating special patient groups (e.g. the elderly) is recognized. The main reasons for tramadol's high significance as a treatment option are: its broad efficacy, an inconspicuous safety profile and its availability, considering that access to strong analgesics - mainly controlled drugs (classical opioids) - is highly restricted in some countries. The CPLA also agreed that tramadol is well tolerated, without the safety issues associated with long-term nonsteroidal anti-inflammatory drug (NSAID) use, with fewer opioid-like side effects than classical opioids and lower abuse risk. In Latin America, tramadol is a valuable and frequently used medication for treating moderate to severe pain. More stringent regulations would have significant impact on its availability, especially for outpatients. This could cause regression to older and frequently inadequate pain management methods, resulting in unnecessary suffering for many Latin American patients.

System Noise Assessment of Blended-Wing-Body Aircraft With Open Rotor Propulsion

NASA Technical Reports Server (NTRS)

Guo, Yueping; Thomas, Russell H.

2015-01-01

An aircraft system noise study is presented for the Blended-Wing-Body (BWB) aircraft concept with three open rotor engines mounted on the upper surface of the airframe. It is shown that for such an aircraft, the cumulative Effective Perceived Noise Level (EPNL) is about 24 dB below the current aircraft noise regulations of Stage 4. While this makes the design acoustically viable in meeting the regulatory requirements, even with the consideration of more stringent noise regulations of a possible Stage 5 in the next decade or so, the design will likely meet stiff competitions from aircraft with turbofan engines. It is shown that the noise levels of the BWB design are held up by the inherently high noise levels of the open rotor engines and the limitation on the shielding benefit due to the practical design constraint on the engine location. Furthermore, it is shown that the BWB design has high levels of noise from the main landing gear, due to their exposure to high speed flow at the junction between the center body and outer wing. These are also the reasons why this baseline BWB design does not meet the NASA N+2 noise goal of 42 dB below Stage 4. To identify approaches that may further reduce noise, parametric studies are also presented, including variations in engine location, vertical tail and elevon variations, and airframe surface acoustic liner treatment effect. These have the potential to further reduce noise but they are only at the conceptual stage.

On-the-fly Locata/inertial navigation system integration for precise maritime application

NASA Astrophysics Data System (ADS)

Jiang, Wei; Li, Yong; Rizos, Chris

2013-10-01

The application of Global Navigation Satellite System (GNSS) technology has meant that marine navigators have greater access to a more consistent and accurate positioning capability than ever before. However, GNSS may not be able to meet all emerging navigation performance requirements for maritime applications with respect to service robustness, accuracy, integrity and availability. In particular, applications in port areas (for example automated docking) and in constricted waterways, have very stringent performance requirements. Even when an integrated inertial navigation system (INS)/GNSS device is used there may still be performance gaps. GNSS signals are easily blocked or interfered with, and sometimes the satellite geometry may not be good enough for high accuracy and high reliability applications. Furthermore, the INS accuracy degrades rapidly during GNSS outages. This paper investigates the use of a portable ground-based positioning system, known as ‘Locata’, which was integrated with an INS, to provide accurate navigation in a marine environment without reliance on GNSS signals. An ‘on-the-fly’ Locata resolution algorithm that takes advantage of geometry change via an extended Kalman filter is proposed in this paper. Single-differenced Locata carrier phase measurements are utilized to achieve accurate and reliable solutions. A ‘loosely coupled’ decentralized Locata/INS integration architecture based on the Kalman filter is used for data processing. In order to evaluate the system performance, a field trial was conducted on Sydney Harbour. A Locata network consisting of eight Locata transmitters was set up near the Sydney Harbour Bridge. The experiment demonstrated that the Locata on-the-fly (OTF) algorithm is effective and can improve the system accuracy in comparison with the conventional ‘known point initialization’ (KPI) method. After the OTF and KPI comparison, the OTF Locata/INS integration is then assessed further and its performance improvement on both stand-alone OTF Locata and INS is shown. The Locata/INS integration can achieve centimetre-level accuracy for position solutions, and centimetre-per-second accuracy for velocity determination.

Role of the Stringent Stress Response in the Antibiotic Resistance Phenotype of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Aedo, Sandra

2016-01-01

Resistance to beta-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA) requires the presence of an acquired genetic determinant, mecA or mecC, which encode penicillin-binding protein PBP2A or PBP2A′, respectively. Although all MRSA strains share a mechanism of resistance, the phenotypic expression of beta-lactam resistance shows considerable strain-to-strain variation. The stringent stress response, a stress response that results from nutrient limitation, was shown to play a key role in determining the resistance level of an MRSA strain. In the present study, we validated the impact of the stringent stress response on transcription and translation of mecA in the MRSA clinical isolate strain N315, which also carries known regulatory genes (mecI/mecR1/mecR2 and blaI/blaR1) for mecA transcription. We showed that the impact of the stringent stress response on the resistance level may be restricted to beta-lactam resistance based on a “foreign” determinant such as mecA, as opposed to resistance based on mutations in the native S. aureus determinant pbpB (encoding PBP2). Our observations demonstrate that high-level resistance mediated by the stringent stress response follows the current model of beta-lactam resistance in which the native PBP2 protein is also essential for expression of the resistance phenotype. We also show that the Staphylococcus sciuri pbpD gene (also called mecAI), the putative evolutionary precursor of mecA, confers oxacillin resistance in an S. aureus strain, generating a heterogeneous phenotype that can be converted to high and homogenous resistance by induction of the stringent stress response in the bacteria. PMID:26833147

Context-Aware Reviewer Assignment for Trust Enhanced Peer Review

PubMed Central

Li, Lei; Wang, Yan; Liu, Guanfeng; Wang, Meng; Wu, Xindong

2015-01-01

Reviewer assignment is critical to peer review systems, such as peer-reviewed research conferences or peer-reviewed funding applications, and its effectiveness is a deep concern of all academics. However, there are some problems in existing peer review systems during reviewer assignment. For example, some of the reviewers are much more stringent than others, leading to an unfair final decision, i.e., some submissions (i.e., papers or applications) with better quality are rejected. In this paper, we propose a context-aware reviewer assignment for trust enhanced peer review. More specifically, in our approach, we first consider the research area specific expertise of reviewers, and the institution relevance and co-authorship between reviewers and authors, so that reviewers with the right expertise are assigned to the corresponding submissions without potential conflict of interest. In addition, we propose a novel cross-assignment paradigm, and reviewers are cross-assigned in order to avoid assigning a group of stringent reviewers or a group of lenient reviewers to the same submission. More importantly, on top of them, we propose an academic CONtext-aware expertise relevanCe oriEnted Reviewer cross-assignmenT approach (CONCERT), which aims to effectively estimate the “true” ratings of submissions based on the ratings from all reviewers, even though no prior knowledge exists about the distribution of stringent reviewers and lenient reviewers. The experiments illustrate that compared with existing approaches, our proposed CONCERT approach can less likely assign more than one stringent reviewers or lenient reviewers to a submission simultaneously and significantly reduce the influence of ratings from stringent reviewers and lenient reviewers, leading to trust enhanced peer review and selection, no matter what kind of distributions of stringent reviewers and lenient reviewers are. PMID:26090849

Cholera Toxin Production during Anaerobic Trimethylamine N-Oxide Respiration Is Mediated by Stringent Response in Vibrio cholerae*

PubMed Central

Oh, Young Taek; Park, Yongjin; Yoon, Mi Young; Bari, Wasimul; Go, Junhyeok; Min, Kyung Bae; Raskin, David M.; Lee, Kang-Mu; Yoon, Sang Sun

2014-01-01

As a facultative anaerobe, Vibrio cholerae can grow by anaerobic respiration. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly promoted during anaerobic growth using trimethylamine N-oxide (TMAO) as an alternative electron acceptor. Here, we investigated the molecular mechanisms of TMAO-stimulated CT production and uncovered the crucial involvement of stringent response in this process. V. cholerae 7th pandemic strain N16961 produced a significantly elevated level of ppGpp, the bacterial stringent response alarmone, during anaerobic TMAO respiration. Bacterial viability was impaired, and DNA replication was also affected under the same growth condition, further suggesting that stringent response is induced. A ΔrelA ΔspoT ppGpp overproducer strain produced an enhanced level of CT, whereas anaerobic growth via TMAO respiration was severely inhibited. In contrast, a ppGpp-null strain (ΔrelA ΔspoT ΔrelV) grew substantially better, but produced no CT, suggesting that CT production and bacterial growth are inversely regulated in response to ppGpp accumulation. Bacterial capability to produce CT was completely lost when the dksA gene, which encodes a protein that works cooperatively with ppGpp, was deleted. In the ΔdksA mutant, stringent response growth inhibition was alleviated, further supporting the inverse regulation of CT production and anaerobic growth. In vivo virulence of ΔrelA ΔspoT ΔrelV or ΔdksA mutants was significantly attenuated. The ΔrelA ΔspoT mutant maintained virulence when infected with exogenous TMAO despite its defective growth. Together, our results reveal that stringent response is activated under TMAO-stimulated anaerobic growth, and it regulates CT production in a growth-dependent manner in V. cholerae. PMID:24648517

Body composition and military performance--many things to many people.

PubMed

Friedl, Karl E

2012-07-01

Soldiers are expected to maintain the highest possible level of physical readiness because they must be ready to mobilize and perform their duties anywhere in the world at any time. The objective of Army body composition standards is to motivate physical training and good nutrition habits to ensure a high state of readiness. Establishment of enforceable and rational standards to support this objective has been challenging even at extremes of body size. Morbidly obese individuals are clearly not suited to military service, but very large muscular individuals may be superbly qualified for soldier performance demands. For this reason, large individuals are measured for body fat using a waist circumference-based equation (female soldiers are also measured for hip circumference). The main challenge comes in setting appropriate fat standards to support the full range of Army requirements. Military appearance ideals dictate the most stringent body fat standards, whereas health risk thresholds anchor the most liberal standards, and physical performance associations fall on a spectrum between these 2 poles. Standards should not exclude or penalize specialized performance capabilities such as endurance running or power lifting across a spectrum of body sizes and fat. The full integration of women into the military further complicates the issue because of sexually dimorphic characteristics that make gender-appropriate standards essential and where inappropriately stringent standards can compromise both health and performance of this segment of the force. Other associations with body composition such as stress effects on intraabdominal fat distribution patterns and metabolic implications of a fat reserve for survival in extreme environments are also relevant considerations. This is a review of the science that underpins the U.S. Army body composition standards.

New aspects relating to the behaviour of composites and adhesives in space

NASA Technical Reports Server (NTRS)

Carpenter, A.

1991-01-01

Some of the specialized testing procedures performed at the JPL Molecular Contamination Investigation Facility for the WideField Planetary Camera II (WFPC II) program for the screening of polymeric materials for outgassing properties are described. For WFPC II, a science performance goal of 1-percent photometric accuracy at 1470 A over an extended time (at least 30 days) has been established. Utilization of the newest technology using CCD detectors poses even more stringent requirements. Test results are presented, and data reduction and modeling techniques are discussed.

The Landsat Data Continuity Mission Operational Land Imager: Pre-Launch Performance

NASA Technical Reports Server (NTRS)

Markham, Brian L.; Knight, Edward J.; Canova, Brent; Donley, Eric; Kvaran, Geir; Lee, Kenton

2011-01-01

The Operational Land Imager(OLI) will be the main instrument on Landsat-8 when it launches in 2012. OLI represents a generational change from heritage Landsat instruments in its design but must maintain data continuity with the 30+ year Landsat data archive. As a result, OLI has undergone a stringent calibration and characterization campaign to ensure its characteristics are understood and consistent with past instruments. This paper presents an overview of the OLI design, its major differences from previous Landsat instruments, and a summary of its expected performance.

Tracker controls development and control architecture for the Hobby-Eberly Telescope Wide Field Upgrade

NASA Astrophysics Data System (ADS)

Mock, Jason R.; Beno, Joe; Rafferty, Tom H.; Cornell, Mark E.

2010-07-01

To enable the Hobby-Eberly Telescope Wide Field Upgrade, the University of Texas Center for Electromechanics and McDonald Observatory are developing a precision tracker system - a 15,000 kg robot to position a 3,100 kg payload within 10 microns of a desired dynamic track. Performance requirements to meet science needs and safety requirements that emerged from detailed Failure Modes and Effects Analysis resulted in a system of 14 precision controlled actuators and 100 additional analog and digital devices (primarily sensors and safety limit switches). This level of system complexity and emphasis on fail-safe operation is typical of large modern telescopes and numerous industrial applications. Due to this complexity, demanding accuracy requirements, and stringent safety requirements, a highly versatile and easily configurable centralized control system that easily links with modeling and simulation tools during the hardware and software design process was deemed essential. The Matlab/Simulink simulation environment, coupled with dSPACE controller hardware, was selected for controls development and realization. The dSPACE real-time operating system collects sensor information; motor commands are transmitted over a PROFIBUS network to servo amplifiers and drive motor status is received over the same network. Custom designed position feedback loops, supplemented by feed forward force commands for enhanced performance, and algorithms to accommodate self-locking gearboxes (for safety), reside in dSPACE. To interface the dSPACE controller directly to absolute Heidenhain sensors with EnDat 2.2 protocol, a custom communication board was developed. This paper covers details of software and hardware, design choices and analysis, and supporting simulations (primarily Simulink).

NASA Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Carter, David; Wetzel, Scott

2000-01-01

The NASA SLR Operational Center is responsible for: 1) NASA SLR network control, sustaining engineering, and logistics; 2) ILRS mission operations; and 3) ILRS and NASA SLR data operations. NASA SLR network control and sustaining engineering tasks include technical support, daily system performance monitoring, system scheduling, operator training, station status reporting, system relocation, logistics and support of the ILRS Networks and Engineering Working Group. These activities ensure the NASA SLR systems are meeting ILRS and NASA mission support requirements. ILRS mission operations tasks include mission planning, mission analysis, mission coordination, development of mission support plans, and support of the ILRS Missions Working Group. These activities ensure than new mission and campaign requirements are coordinated with the ILRS. Global Normal Points (NP) data, NASA SLR FullRate (FR) data, and satellite predictions are managed as part of data operations. Part of this operation includes supporting the ILRS Data Formats and Procedures Working Group. Global NP data operations consist of receipt, format and data integrity verification, archiving and merging. This activity culminates in the daily electronic transmission of NP files to the CDDIS. Currently of all these functions are automated. However, to ensure the timely and accurate flow of data, regular monitoring and maintenance of the operational software systems, computer systems and computer networking are performed. Tracking statistics between the stations and the data centers are compared periodically to eliminate lost data. Future activities in this area include sub-daily (i.e., hourly) NP data management, more stringent data integrity tests, and automatic station notification of format and data integrity issues.

Is bigger better? Driving factors of POTW performance in New York.

PubMed

Rahm, Brian G; Morse, Natalie; Bowen, Michelle; Choi, Jun; Mehta, Dhaval; Vedachalam, Sridhar

2018-05-15

Like many regions around the world, New York State, USA, faces challenges in meeting wastewater treatment quality standards because of aging infrastructure, limited funding, shifting demographics and increasingly stringent environmental regulations. In recent decades construction of new wastewater treatment and distribution infrastructure in NY has most often occurred in exurban communities and suburban developments that are less dense than traditional urban cores. Here, we examine the role of size and capacity utilization on wastewater treatment effectiveness with respect to critical effluent parameters, and additionally explore which common facility engineering controls influence water quality treatment using a unique dataset of descriptive information. Our results challenge conventional wisdom, suggesting that the largest facilities (>30,000 m 3 /d), not the smallest (<300 m 3 /d), discharge TSS, BOD, and coliform at significantly higher relative effluent concentrations (i.e., the ratio of discharged concentrations to allowable limits). Capacity utilization was also positively correlated to higher concentrations of TSS, BOD, and coliform effluent concentrations in larger facilities, though those concentrations were often within regulated limits. This implies that smaller-sized facilities may perform better in terms of environmental quality, but that the largest facilities demonstrate efficiency in the sense that they are not "over-treating" wastewater while avoiding violations. Results from NY suggest that medium sized facilities (300-30,000 m 3 /d) are sophisticated enough to incorporate appropriate unit processes, and employ operators with sufficient training and oversight, to reach treatment outcomes that are both reliable and of high quality. Copyright © 2018 Elsevier Ltd. All rights reserved.

Messiah College Biodiesel Fuel Generation Project Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zummo, Michael M; Munson, J; Derr, A

Many obvious and significant concerns arise when considering the concept of small-scale biodiesel production. Does the fuel produced meet the stringent requirements set by the commercial biodiesel industry? Is the process safe? How are small-scale producers collecting and transporting waste vegetable oil? How is waste from the biodiesel production process handled by small-scale producers? These concerns and many others were the focus of the research preformed in the Messiah College Biodiesel Fuel Generation project over the last three years. This project was a unique research program in which undergraduate engineering students at Messiah College set out to research the feasibilitymore » of small-biodiesel production for application on a campus of approximately 3000 students. This Department of Energy (DOE) funded research program developed out of almost a decade of small-scale biodiesel research and development work performed by students at Messiah College. Over the course of the last three years the research team focused on four key areas related to small-scale biodiesel production: Quality Testing and Assurance, Process and Processor Research, Process and Processor Development, and Community Education. The objectives for the Messiah College Biodiesel Fuel Generation Project included the following: 1. Preparing a laboratory facility for the development and optimization of processors and processes, ASTM quality assurance, and performance testing of biodiesel fuels. 2. Developing scalable processor and process designs suitable for ASTM certifiable small-scale biodiesel production, with the goals of cost reduction and increased quality. 3. Conduct research into biodiesel process improvement and cost optimization using various biodiesel feedstocks and production ingredients.« less

High dynamic range pixel architecture for advanced diagnostic medical x-ray imaging applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izadi, Mohammad Hadi; Karim, Karim S.

2006-05-15

The most widely used architecture in large-area amorphous silicon (a-Si) flat panel imagers is a passive pixel sensor (PPS), which consists of a detector and a readout switch. While the PPS has the advantage of being compact and amenable toward high-resolution imaging, small PPS output signals are swamped by external column charge amplifier and data line thermal noise, which reduce the minimum readable sensor input signal. In contrast to PPS circuits, on-pixel amplifiers in a-Si technology reduce readout noise to levels that can meet even the stringent requirements for low noise digital x-ray fluoroscopy (<1000 noise electrons). However, larger voltagesmore » at the pixel input cause the output of the amplified pixel to become nonlinear thus reducing the dynamic range. We reported a hybrid amplified pixel architecture based on a combination of PPS and amplified pixel designs that, in addition to low noise performance, also resulted in large-signal linearity and consequently higher dynamic range [K. S. Karim et al., Proc. SPIE 5368, 657 (2004)]. The additional benefit in large-signal linearity, however, came at the cost of an additional pixel transistor. We present an amplified pixel design that achieves the goals of low noise performance and large-signal linearity without the need for an additional pixel transistor. Theoretical calculations and simulation results for noise indicate the applicability of the amplified a-Si pixel architecture for high dynamic range, medical x-ray imaging applications that require switching between low exposure, real-time fluoroscopy and high-exposure radiography.« less

Improving multispectral satellite image compression using onboard subpixel registration

NASA Astrophysics Data System (ADS)

Albinet, Mathieu; Camarero, Roberto; Isnard, Maxime; Poulet, Christophe; Perret, Jokin

2013-09-01

Future CNES earth observation missions will have to deal with an ever increasing telemetry data rate due to improvements in resolution and addition of spectral bands. Current CNES image compressors implement a discrete wavelet transform (DWT) followed by a bit plane encoding (BPE) but only on a mono spectral basis and do not profit from the multispectral redundancy of the observed scenes. Recent CNES studies have proven a substantial gain on the achievable compression ratio, +20% to +40% on selected scenarios, by implementing a multispectral compression scheme based on a Karhunen Loeve transform (KLT) followed by the classical DWT+BPE. But such results can be achieved only on perfectly registered bands; a default of registration as low as 0.5 pixel ruins all the benefits of multispectral compression. In this work, we first study the possibility to implement a multi-bands subpixel onboard registration based on registration grids generated on-the-fly by the satellite attitude control system and simplified resampling and interpolation techniques. Indeed bands registration is usually performed on ground using sophisticated techniques too computationally intensive for onboard use. This fully quantized algorithm is tuned to meet acceptable registration performances within stringent image quality criteria, with the objective of onboard real-time processing. In a second part, we describe a FPGA implementation developed to evaluate the design complexity and, by extrapolation, the data rate achievable on a spacequalified ASIC. Finally, we present the impact of this approach on the processing chain not only onboard but also on ground and the impacts on the design of the instrument.

CHEOPS: status summary of the instrument development

NASA Astrophysics Data System (ADS)

Beck, T.; Broeg, C.; Fortier, A.; Cessa, V.; Malvasio, L.; Piazza, D.; Benz, W.; Thomas, N.; Magrin, D.; Viotto, V.; Bergomi, M.; Ragazzoni, R.; Pagano, I.; Peter, G.; Buder, M.; Plesseria, J. Y.; Steller, M.; Ottensamer, R.; Ehrenreich, D.; Van Damme, C.; Isaak, K.; Ratti, F.; Rando, N.; Ngan, I.

2016-07-01

CHEOPS (CHaracterizing ExOPlanets Satellite) is the first ESA Small Mission as part of the ESA Cosmic Vision program 2015-2025. The mission was formally adopted in early February 2014 with a planned launch readiness end of 2017. The mission lead is performed in a partnership between Switzerland, led by the University of Bern, and the European Space Agency with important contributions from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The mission is dedicated to searching for exoplanetary transits by performing ultrahigh precision photometry on bright starts already known to host planets whose mass has been already estimated through ground based observations. The instrument is an optical Ritchey-Chretien telescope of 30 cm clear aperture using a single CCD detector. The optical system is designed to image a de-focused PSF onto the focal plane with very stringent stability and straylight rejection requirements providing a FoV of 0.32 degrees full cone. The system design is adapted to meet the top-level science requirements, which ask for a photometric precision of 20ppm, in 6 hours integration time, on transit measurements of G5 dwarf stars with V-band magnitudes in the range 6≤V≤9 mag. Additionally they ask for a photometric precision of 85 ppm in 3 hours integration time of Neptune-size planets transiting K-type dwarf stars with V-band magnitudes as faint as V=12 mag. Given the demanding schedule and cost constrains, the mission relies mostly on components with flight heritage for the platform as well as for the payload components. Nevertheless, several new developments are integrated into the design as for example the telescope structure and the very low noise, high stability CCD front end electronics. The instrument and mission have gone through critical design review in fall 2015 / spring 2016. This paper describes the current instrument and mission design with a focus on the instrument. It outlines the technical challenges and selected design implementation. Based on the current status, the instrument noise budget is presented including the current best estimate for instrument performance. The current instrument design meets the science requirements and mass and power margins are adequate for the current development status.

A New Generation of Micro Satellite Radiometers for Atmospheric Remote Sensing

NASA Astrophysics Data System (ADS)

He, jieying

2017-04-01

The need for low-cost, mission-flexible, and rapidly deployable space borne sensors that meet stringent performance requirements pervades the extreme weather monitoring programs, including especially the strong rainfall and typhoon. New technologies have enabled a novel approach toward this science observational goal, and in this paper we describe recent technology develop efforts to address the challenges above through the use of radiometers on a Micro-sized Microwave Atmospheric Satellite (Microsat), which operates in the type of constellation, and enable the capabilities of rapidly progressing. Recent work has involved the design and development of highly integrated radiometer component technologies that would enable the realization of a high-performance, multi-band sounder that would conform to the 3U CubeSat size (10 x 10 x 30 cm), weight, and power requirements. This paper partly focuses on the constellation to realize a scalable CubeSat-based system that will pave the path towards improved revisit rates over critical earth regions, and achieve state-of-the-art performance relative to current systems with respect to spatial, spectral, and radiometric resolution. As one of the important payloads on the platform, sub-millimeter radiometer is advised to house for providing atmospheric and oceanographic information all weather and all day. The first portion of the radiometer comprises a horn-fed reflector antenna, with a full-width at half-maximum (FWHM) beamwidth of 1.2°. Hence, the scanned beam has an approximate footprint diameter of 9.6 km at nadir incidence from a nominal altitude of 500 km. The antenna system is designed for a minimum 95% beam efficiency. Approximately 98 pixels are sampled for every scanning line, which covers a range of 1500km. The period of a round is about 94.47 minutes and re-visit period is four days. For the radiometer, which is a passive cross-track-scanning microwave spectrometer operating near the 118.75-GHz oxygen absorption line and 183 water vapor line for more than 100 channels based on high-speed digital processing technique, with a calibration accuracy of 0.5K for each channel to ensure the capability of temperature and ice-cloud retrievals. To meet the requirements of spatial and temporal specifications, a primarily concept of 41 Microsats in constellation are considered to achieve the retrievals in the resolution of 10km and 10 minutes.

Vision Technology for Automated Inspection of Hybrid Microelectronics Assemblies

DTIC Science & Technology

1988-06-01

circuits are a very efficient packaging technique, with the primary advantages of size, better resistance to environ - 0 ments, and the flexibility to...produced for the military are much more complex and have more stringent performance requirements, particularly in their resistance to environments and...boards, particularly because of the need to protect circuits from a hostile environment such as salt, heat, and moisture. Included among the major U.S

Prospects and Pitfalls in the Coming Wave of High-frequency Environmental Data: What to Look Forward to, and Watch out for

NASA Astrophysics Data System (ADS)

Keller, A. A.; Adeleye, A. S.; Huang, Y.; Garner, K.

2014-12-01

The application of nanotechnology in drinking water treatment and pollution cleanup is promising, as demonstrated by a number of field-based (pilot and full scale) and bench scale studies. A number of reviews exist for these nanotechnology-based applications; but to better illustrate its importance and guide its development, a direct comparison between traditional treatment technologies and emerging approaches using nanotechnology is needed. In this review, the performances of traditional technologies and nanotechnology for water treatment and environmental remediation were compared with the goal of providing an up-to-date reference on the state of treatment techniques for researchers, industry, and policy makers. Pollutants were categorized into broad classes, and the most cost-effective techniques (traditional and nanotechnology-based) in each category reported in the literature were compared. Where information was available, cost and environmental implications of both technologies were also compared. Traditional treatment technologies were found to currently offer the most cost-effective choices for removal of several common pollutants from drinking water and polluted sites. Nano-based techniques may however become important in complicated remediation conditions and meeting increasingly stringent water quality standards, especially in removal of emerging pollutants and low levels of contaminants. We also discuss challenges facing environmental application of nanotechnology were also discussed and potential solutions.

A Novel Method for Quantifying Helmeted Field of View of a Spacesuit - And What It Means for Constellation

NASA Technical Reports Server (NTRS)

McFarland, Shane M.

2010-01-01

Field of view has always been a design feature paramount to helmet design, and in particular spacesuit design, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. Historically, suited field of view has been evaluated either qualitatively in parallel with design or quantitatively using various test methods and protocols. As such, oftentimes legacy suit field of view information is either ambiguous for lack of supporting data or contradictory to other field of view tests performed with different subjects and test methods. This paper serves to document a new field of view testing method that is more reliable and repeatable than its predecessors. It borrows heavily from standard ophthalmologic field of vision tests such as the Goldmann kinetic perimetry test, but is designed specifically for evaluating field of view of a spacesuit helmet. In this test, four suits utilizing three different helmet designs were tested for field of view. Not only do these tests provide more reliable field of view data for legacy and prototype helmet designs, they also provide insight into how helmet design impacts field of view and what this means for the Constellation Project spacesuit helmet, which must meet stringent field of view requirements that are more generous to the crewmember than legacy designs.

Laboratory directed research and development FY98 annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Ayat, R; Holzrichter, J

1999-05-01

In 1984, Congress and the Department of Energy (DOE) established the Laboratory Directed Research and Development (LDRD) Program to enable the director of a national laboratory to foster and expedite innovative research and development (R and D) in mission areas. The Lawrence Livermore National Laboratory (LLNL) continually examines these mission areas through strategic planning and shapes the LDRD Program to meet its long-term vision. The goal of the LDRD Program is to spur development of new scientific and technical capabilities that enable LLNL to respond to the challenges within its evolving mission areas. In addition, the LDRD Program provides LLNLmore » with the flexibility to nurture and enrich essential scientific and technical competencies and enables the Laboratory to attract the most qualified scientists and engineers. The FY98 LDRD portfolio described in this annual report has been carefully structured to continue the tradition of vigorously supporting DOE and LLNL strategic vision and evolving mission areas. The projects selected for LDRD funding undergo stringent review and selection processes, which emphasize strategic relevance and require technical peer reviews of proposals by external and internal experts. These FY98 projects emphasize the Laboratory's national security needs: stewardship of the U.S. nuclear weapons stockpile, responsibility for the counter- and nonproliferation of weapons of mass destruction, development of high-performance computing, and support of DOE environmental research and waste management programs.« less

TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

PubMed

Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

2015-01-01

A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

Review of modern low emissions combustion technologies for aero gas turbine engines

NASA Astrophysics Data System (ADS)

Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Nalianda, Devaiah; Li, Yi-Guang; Wang, Lu

2017-10-01

Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of the review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.

Cyber Safety and Security for Reduced Crew Operations (RCO)

NASA Technical Reports Server (NTRS)

Driscoll, Kevin

2017-01-01

NASA and the Aviation Industry is looking into reduced crew operations (RCO) that would cut today's required two-person flight crews down to a single pilot with support from ground-based crews. Shared responsibility across air and ground personnel will require highly reliable and secure data communication and supporting automation, which will be safety-critical for passenger and cargo aircraft. This paper looks at the different types and degrees of authority delegation given from the air to the ground and the ramifications of each, including the safety and security hazards introduced, the mitigation mechanisms for these hazards, and other demands on an RCO system architecture which would be highly invasive into (almost) all safety-critical avionics. The adjacent fields of unmanned aerial systems and autonomous ground vehicles are viewed to find problems that RCO may face and related aviation accident scenarios are described. The paper explores possible data communication architectures to meet stringent performance and information security (INFOSEC) requirements of RCO. Subsequently, potential challenges for RCO data communication authentication, encryption and non-repudiation are identified. The approach includes a comprehensive safety-hazard analysis of the RCO system to determine top level INFOSEC requirements for RCO and proposes an option for effective RCO implementation. This paper concludes with questioning the economic viability of RCO in light of the expense of overcoming the operational safety and security hazards it would introduce.

76 FR 20850 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Stage I Vapor Recovery Rule

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... gasoline dispensing facilities more stringent by applying them statewide, making the rule applicable to... Emissions Standards for Hazardous Air Pollutants (NESHAPs) for gasoline dispensing facilities. The revisions... January 10, 2008, EPA issued new, more stringent National Regulations for Gasoline Dispensing Facilities...

40 CFR 281.37 - Financial responsibility for UST systems containing petroleum.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Financial responsibility for UST... for No-Less-Stringent § 281.37 Financial responsibility for UST systems containing petroleum. (a) In order to be considered no less stringent than the federal requirements for financial responsibility for...

49 CFR 355.21 - Regulatory review.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) It applies to interstate commerce; (iii) It is more stringent than the FMCSRs in that it is more... law or regulation applies to interstate commerce and is more stringent than the FMCSRs, the State shall determine: (i) The safety benefits associated with such State law or regulation; and (ii) The...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be published in the Federal Register. (b) Any State law or regulation which provides for more stringent land use and environmental controls and regulations of coal exploration and surface coal mining... the control and regulation of coal exploration and surface coal mining and reclamation operations for...

40 CFR 503.5 - Additional or more stringent requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements. 503.5 Section 503.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR DISPOSAL OF SEWAGE SLUDGE General Provisions § 503.5 Additional or more... the use or disposal of sewage sludge in addition to or more stringent than the requirements in this...

Problems of Technology of Energy-Saving Buildings and Their Impact on Energy Efficiency in Buildings

NASA Astrophysics Data System (ADS)

Kwasnowski, Pawel; Fedorczak-Cisak, Malgorzata; Knap, Katarzyna

2017-10-01

Introduction of EPBD in legislation of the EU member states caused that buildings must meet very stringent requirements of thermal protection and energy efficiency. On the basis of EPBD provisions, EU Member States introduce standard of NZEB (Nearly Zero-Energy Buildings). Such activities cause a need for new, innovative materials and technologies, and new approaches to design, construction and retrofitting of buildings. Indispensable is the precise coordination of the design of structure and technical installations of building, which may be provided in an integrated design process in the system BIM. Good coordination and cooperation of all contractors during the construction phase is also necessary. The article presents the problems and the new methodology for the design, construction and use of energy efficient buildings in terms of energy saving technologies, including discussion of the significant impact of the automation of technical installations on the building energy efficiency.

Applications and challenges of multivalent recombinant vaccines

PubMed Central

Naim, Hussein Y.

2013-01-01

The exceptional discoveries of antigen/gene delivery systems have allowed the development of novel prophylactic and therapeutic vaccine candidates. The vaccine candidates employ various antigen-delivery systems, particularly recombinant viral vectors. Recombinant viral vectors are experimental vaccines similar to DNA vaccines, but they use attenuated viruses or bacterium as a carrier “vector” to introduce microbial DNA to cells of the body. They closely mimic a natural infection and therefore can efficiently stimulate the immune system. Although such recombinant vectors may face extensive preclinical testing and will possibly have to meet stringent regulatory requirements, some of these vectors (e.g. measles virus vectors) may benefit from the profound industrial and clinical experience of the parent vaccine. Most notably, novel vaccines based on live attenuated viruses combine the induction of broad, strong and persistent immune responses with acceptable safety profiles. We assess certain technologies in light of their use against human immunodeficiency virus (HIV). PMID:23249651

Ver-i-Fus: an integrated access control and information monitoring and management system

NASA Astrophysics Data System (ADS)

Thomopoulos, Stelios C.; Reisman, James G.; Papelis, Yiannis E.

1997-01-01

This paper describes the Ver-i-Fus Integrated Access Control and Information Monitoring and Management (IAC-I2M) system that INTELNET Inc. has developed. The Ver-i-Fus IAC-I2M system has been designed to meet the most stringent security and information monitoring requirements while allowing two- way communication between the user and the system. The systems offers a flexible interface that permits to integrate practically any sensing device, or combination of sensing devices, including a live-scan fingerprint reader, thus providing biometrics verification for enhanced security. Different configurations of the system provide solutions to different sets of access control problems. The re-configurable hardware interface, tied together with biometrics verification and a flexible interface that allows to integrate Ver-i-Fus with an MIS, provide an integrated solution to security, time and attendance, labor monitoring, production monitoring, and payroll applications.

Review of current interest and research in water hyacinth-based wastewater treatment

NASA Technical Reports Server (NTRS)

Markarian, R. K.; Balon, J. E.; Robinson, A. C.

1977-01-01

The status of activity in the user community for water hyacinth-based wastewater treatment was evaluated. The principal technique used was that of interviewing people who either (1) were known to be engaged in hyacinth research or development or (2) had made inquiry to NASA about hyacinth systems. About 40 non-research organizations and a similar number of research organizations were contacted. As a result of the interviews and a review of the relevant literature, it was concluded that hyacinth systems have the potential for providing a lower cost way for small cities to meet increasingly stringent effluent requirements. A limited amount of full-scale demonstration of hyacinth systems has been carried out during the past two years, but the yield of design data has been small. Several organizations are currently planning construction of experimental full-scale hyacinth-based wastewater treatment systems during 1977-1978.

Design and Development of a Regenerative Blower for EVA Suit Ventilation

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Chen, Weibo; Hill, Roger W.; Phillips, Scott D.; Paul, Heather L.

2011-01-01

Ventilation subsystems in future space suits require a dedicated ventilation fan. The unique requirements for the ventilation fan - including stringent safety requirements and the ability to increase output to operate in buddy mode - combine to make a regenerative blower an attractive choice. This paper describes progress in the design, development, and testing of a regenerative blower designed to meet requirements for ventilation subsystems in future space suits. We have developed analysis methods for the blower s complex, internal flows and identified impeller geometries that enable significant improvements in blower efficiency. We verified these predictions by test, measuring aerodynamic efficiencies of 45% at operating conditions that correspond to the ventilation fan s design point. We have developed a compact motor/controller to drive the blower efficiently at low rotating speed (4500 rpm). Finally, we have assembled a low-pressure oxygen test loop to demonstrate the blower s reliability under prototypical conditions.

Environmental policy constraints for acidic exhaust gas scrubber discharges from ships.

PubMed

Ülpre, H; Eames, I

2014-11-15

Increasingly stringent environmental legislation on sulphur oxide emissions from the combustion of fossil fuels onboard ships (International Maritime Organization (IMO) Regulation 14) can be met by either refining the fuel to reduce sulphur content or by scrubbing the exhaust gases. Commonly used open loop marine scrubbers discharge warm acidic exhaust gas wash water into the sea, depressing its pH. The focus on this paper is on the physics and chemistry behind the disposal of acidic discharges in seawater. The IMO Marine Environment Protection Committee (MEPC 59/24/Add.1 Annex 9) requires the wash water to reach a pH greater than 6.5 at a distance of 4m from the point of discharge. We examine the engineering constraints, specifically size and number of ports, to identify the challenges of meeting regulatory compliance. Copyright © 2014. Published by Elsevier Ltd.

Prediction and Characterization of NaGaS2, A High Thermal Conductivity Mid-Infrared Nonlinear Optical Material for High-Power Laser Frequency Conversion.

PubMed

Hou, Dianwei; Nissimagoudar, Arun S; Bian, Qiang; Wu, Kui; Pan, Shilie; Li, Wu; Yang, Zhihua

2018-06-15

Infrared nonlinear optical (IR NLO) crystals are the major materials to widen the output range of solid-state lasers to mid- or far-infrared regions. The IR NLO crystals used in the middle IR region are still inadequate for high-power laser applications because of deleterious thermal effects (lensing and expansion), low laser-induced damage threshold, and two-photon absorption. Herein, the unbiased global minimum search method was used for the first time to search for IR NLO optical materials and ultimately found a new IR NLO material NaGaS 2 . It meets the stringent demands for IR NLO materials pumped by high-power laser with the highest thermal conductivity among common IR NLO materials able to avoid two-photon absorption, a classic nonlinear coefficient, and wide infrared transparency.

Open Rotor Noise Prediction Methods at NASA Langley- A Technology Review

NASA Technical Reports Server (NTRS)

Farassat, F.; Dunn, Mark H.; Tinetti, Ana F.; Nark, Douglas M.

2009-01-01

Open rotors are once again under consideration for propulsion of the future airliners because of their high efficiency. The noise generated by these propulsion systems must meet the stringent noise standards of today to reduce community impact. In this paper we review the open rotor noise prediction methods available at NASA Langley. We discuss three codes called ASSPIN (Advanced Subsonic-Supersonic Propeller Induced Noise), FW - Hpds (Ffowcs Williams-Hawkings with penetrable data surface) and the FSC (Fast Scattering Code). The first two codes are in the time domain and the third code is a frequency domain code. The capabilities of these codes and the input data requirements as well as the output data are presented. Plans for further improvements of these codes are discussed. In particular, a method based on equivalent sources is outlined to get rid of spurious signals in the FW - Hpds code.

A One-Step Route to CO2 -Based Block Copolymers by Simultaneous ROCOP of CO2 /Epoxides and RAFT Polymerization of Vinyl Monomers.

PubMed

Wang, Yong; Zhao, Yajun; Ye, Yunsheng; Peng, Haiyan; Zhou, Xingping; Xie, Xiaolin; Wang, Xianhong; Wang, Fosong

2018-03-26

The one-step synthesis of well-defined CO 2 -based diblock copolymers was achieved by simultaneous ring-opening copolymerization (ROCOP) of CO 2 /epoxides and RAFT polymerization of vinyl monomers using a trithiocarbonate compound bearing a carboxylic group (TTC-COOH) as the bifunctional chain transfer agent (CTA). The double chain-transfer effect allows for independent and precise control over the molecular weight of the two blocks and ensures narrow polydispersities of the resultant block copolymers (1.09-1.14). Notably, an unusual axial group exchange reaction between the aluminum porphyrin catalyst and TTC-COOH impedes the formation of homopolycarbonates. By taking advantage of the RAFT technique, it is able to meet the stringent demand for functionality control to well expand the application scopes of CO 2 -based polycarbonates. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fuel processing requirements and techniques for fuel cell propulsion power

NASA Astrophysics Data System (ADS)

Kumar, R.; Ahmed, S.; Yu, M.

Fuels for fuel cells in transportation systems are likely to be methanol, natural gas, hydrogen, propane, or ethanol. Fuels other than hydrogen will need to be reformed to hydrogen on-board the vehicle. The fuel reformer must meet stringent requirements for weight and volume, product quality, and transient operation. It must be compact and lightweight, must produce low levels of CO and other byproducts, and must have rapid start-up and good dynamic response. Catalytic steam reforming, catalytic or noncatalytic partial oxidation reforming, or some combination of these processes may be used. This paper discusses salient features of the different kinds of reformers and describes the catalysts and processes being examined for the oxidation reforming of methanol and the steam reforming of ethanol. Effective catalysts and reaction conditions for the former have been identified; promising catalysts and reaction conditions for the latter are being investigated.

Nutation and precession control of the High Energy Solar Physics (HESP) satellite

NASA Technical Reports Server (NTRS)

Jayaraman, C. P.; Robertson, B. P.

1993-01-01

The High Energy Solar Physics (HESP) spacecraft is an intermediate class satellite proposed by NASA to study solar high-energy phenomena during the next cycle of high solar activity in the 1998 to 2005 time frame. The HESP spacecraft is a spinning satellite which points to the sun with stringent pointing requirements. The natural dynamics of a spinning satellite includes an undesirable effect: nutation, which is due to the presence of disturbances and offsets of the spin axis from the angular momentum vector. The proposed Attitude Control System (ACS) attenuates nutation with reaction wheels. Precessing the spacecraft to track the sun in the north-south and east-west directions is accomplished with the use of torques from magnetic torquer bars. In this paper, the basic dynamics of a spinning spacecraft are derived, control algorithms to meet HESP science requirements are discussed and simulation results to demonstrate feasibility of the ACS concept are presented.

Electronic structure and optical properties of some anthocyanins extracted from grapes

NASA Astrophysics Data System (ADS)

Iosub, Ion; Kajzar, Francois; Makowska-Janusik, Malgorzata; Meghea, Aurelia; Tane, Alexandrina; Rau, Ileana

2012-08-01

The pallet of applications of natural dyes and pigments is continuously extending as a stringent need to meet the challenges arisen from sustainable development, particularly related to replacing synthetic chemicals by eco-friendly renewable raw materials. In this respect, the well known nutritive and therapeutic properties demonstrated by anthocyanin compounds present in selective plant extracts of numerous fruits, vegetables and flowers could be largely complemented by their characteristics as chromophores and fluorophores with high potential in promising applications in bio-imaging for diagnostic and therapy, but also in electronic and photonic devices, solar cells, etc. In this context, this paper proposes an improved protocol for extraction and HPLC detection of anthocyanins from black grapes. Moreover, in order to exploit their potential to be applied as chromatic and fluorescence molecular probes, the electronic properties have been studied by correlating spectral characteristics with trichromatic parameters, combined with quantum chemistry computation.

Natural environment application for NASP-X-30 design and mission planning

NASA Technical Reports Server (NTRS)

Johnson, D. L.; Hill, C. K.; Brown, S. C.; Batts, G. W.

1993-01-01

The NASA/MSFC Mission Analysis Program has recently been utilized in various National Aero-Space Plane (NASP) mission and operational planning scenarios. This paper focuses on presenting various atmospheric constraint statistics based on assumed NASP mission phases using established natural environment design, parametric, threshold values. Probabilities of no-go are calculated using atmospheric parameters such as temperature, humidity, density altitude, peak/steady-state winds, cloud cover/ceiling, thunderstorms, and precipitation. The program although developed to evaluate test or operational missions after flight constraints have been established, can provide valuable information in the design phase of the NASP X-30 program. Inputting the design values as flight constraints the Mission Analysis Program returns the probability of no-go, or launch delay, by hour by month. This output tells the X-30 program manager whether the design values are stringent enough to meet his required test flight schedules.

Fimag: the United Kingdom disaster victim/forensic identification imaging system.

PubMed

Rutty, Guy N; Robinson, Claire; Morgan, Bruno; Black, Sue; Adams, Catherine; Webster, Philip

2009-11-01

Imaging is an integral diagnostic tool in mass fatality investigations undertaken traditionally by plain X-rays, fluoroscopy, and dental radiography. However, little attention has been given to appropriate image reporting, secure data transfer and storage particularly in relation to the need to meet stringent judicial requirements. Notwithstanding these limitations, it is the risk associated with the safe handling and investigation of contaminated fatalities which is providing new challenges for mass fatality radiological imaging. Mobile multi-slice computed tomography is an alternative to these traditional modalities as it provides a greater diagnostic yield and an opportunity to address the requirements of the criminal justice system. We present a new national disaster victim/forensic identification imaging system--Fimag--which is applicable for both contaminated and non-contaminated mass fatality imaging and addresses the issues of judicial reporting. We suggest this system opens a new era in radiological diagnostics for mass fatalities.

Best performing definition of accelerated knee osteoarthritis: data from the Osteoarthritis Initiative

PubMed Central

Driban, Jeffrey B.; Stout, Alina C.; Lo, Grace H.; Eaton, Charles B.; Price, Lori Lyn; Lu, Bing; Barbe, Mary F.; McAlindon, Timothy E.

2016-01-01

Background: We evaluated agreement among several definitions of accelerated knee osteoarthritis (AKOA) and construct validity by comparing their individual associations with injury, age, obesity, and knee pain. Methods: We selected knees from the Osteoarthritis Initiative that had no radiographic knee osteoarthritis [Kellgren–Lawrence (KL) 0 or 1] at baseline and had high-quality quantitative medial joint space width (JSW) measures on two or more consecutive visits (n = 1655 knees, 1143 participants). Quantitative medial JSW was based on a semi-automated method and was location specific (x = 0.25). We compared six definitions of AKOA: stringent JSW (averaged): average JSW loss greater than 1.05 mm/year over 4 years; stringent JSW (consistent): JSW loss greater than 1.05 mm/year for at least 2 years; lenient JSW (averaged): average JSW loss greater than 0.25 mm/year over 4 years; lenient JSW (consistent): JSW loss greater than 0.25 mm/year for at least 2 years; comprehensive KL based: progression from no radiographic osteoarthritis to advance-stage osteoarthritis (KL 3 or 4; development of definite osteophyte and joint space narrowing) within 4 years; and lenient KL based: an increase of at least two KL grades within 4 years. Results: Over 4 years the incidence rate of AKOA was 0.4%, 0.8%, 15.5%, 22.1%, 12.4%, and 7.2% based on the stringent JSW (averaged and consistent), lenient JSW (averaged and consistent), lenient KL-based definition, and comprehensive KL-based definition. All but one knee that met the stringent JSW definition also met the comprehensive KL-based definition. There was fair substantial agreement between the lenient JSW (averaged), lenient KL-based, and comprehensive KL-based definitions. A comprehensive KL-based definition led to larger effect sizes for injury, age, body mass index, and average pain over 4 years. Conclusions: A comprehensive KL-based definition of AKOA may be ideal because it represents a broader definition of joint deterioration compared with those focused on just joint space or osteophytes alone. PMID:27721902

Influence of diagnostic criteria on the interpretation of adrenal vein sampling.

PubMed

Lethielleux, Gaëlle; Amar, Laurence; Raynaud, Alain; Plouin, Pierre-François; Steichen, Olivier

2015-04-01

Guidelines promote the use of adrenal vein sampling (AVS) to document lateralized aldosterone hypersecretion in primary aldosteronism. However, there are large discrepancies between institutions in the criteria used to interpret its results. This study evaluates the consequences of these differences on the classification and management of patients. The results of all 537 AVS procedures performed between January 2001 and July 2010 in our institution were interpreted with 4 diagnostic criteria used in experienced institutions where AVS is performed without cosyntropin (Brisbane, Padua, Paris, and Turin) and with criteria proposed by a recent consensus statement. AVS procedures were classified as unsuccessful, lateralized, or not lateralized according to each set of criteria. Almost 5× more AVS procedures were classified as unsuccessful with the strictest criteria than with the least strict criteria (18% versus 4%, respectively). Similarly, over 2× more AVS procedures were classified as lateralized with the least stringent criteria than with the most stringent criteria (60% versus 26%, respectively). Multiple samples were available from ≥1 side for 155 AVS procedures. These procedures were classified differently by ≥2 right-left sample pairs in 12% to 20% of cases. Thus, different sets of criteria used to interpret AVS in experienced institutions translate into heterogeneous classifications and hence management decisions, for patients with primary aldosteronism. Defining the most appropriate procedures and diagnostic criteria is needed for AVS to achieve optimal performance and fully justify its status as a gold standard. © 2015 American Heart Association, Inc.

Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Frankenberg, Christian; Kulawik, Susan S.; Wofsy, Steven C.; Chevallier, Frédéric; Daube, Bruce; Kort, Eric A.; O'Dell, Christopher; Olsen, Edward T.; Osterman, Gregory

2016-06-01

In recent years, space-borne observations of atmospheric carbon dioxide (CO2) have been increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column-averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network (TCCON). Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) flights from 01/2009 through 09/2011 to validate CO2 measurements from satellites (Greenhouse Gases Observing Satellite - GOSAT, Thermal Emission Sounder - TES, Atmospheric Infrared Sounder - AIRS) and atmospheric inversion models (CarbonTracker CT2013B, Monitoring Atmospheric Composition and Climate (MACC) v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, in particular at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of -0.06 ppm, and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm, and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm, and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20, and 50 atmospheric soundings have been averaged for GOSAT, TES, and AIRS, respectively. Overall, we find that GOSAT soundings over the remote Pacific Ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

Dynamic Loading Assembly for Testing Actuators of Segmented Mirror Telescope

NASA Astrophysics Data System (ADS)

Deshmukh, Prasanna Gajanan; Parihar, Padmakar; Balasubramaniam, Karthik A.; Mishra, Deepta Sundar; Mahesh, P. K.

Upcoming large telescopes are based on Segmented Mirror Telescope (SMT) technology which uses small hexagonal mirror segments placed side by side to form the large monolithic surface. The segments alignment needs to be maintained against external disturbances like wind, gravity, temperature and structural vibration. This is achieved by using three position actuators per segment working at few-nanometer scale range along with a local closed loop controller. The actuator along with a controller is required to meet very stringent performance requirements, such as track rates up to 300nm/s (90mN/s) with tracking errors less than 5nm, dynamical forces of up to ±40N, ability to reject disturbances introduced by the wind as well as by mechanical vibration generated in the mirror cell, etc. To conduct these performance tests in more realistic manner, we have designed and developed a Dynamic Loading Assembly (DLA) at Indian Institute of Astrophysics (IIA), Bangalore. DLA is a computer controlled force-inducing device, designed in a modular fashion to generate different types of user-defined disturbances in extremely precise and controlled manner. Before realizing the device, using a simple spring-mass-damper-based mathematical model, we ensured that the concept would indeed work. Subsequently, simple concept was converted into a detailed mechanical design and parts were manufactured and assembled. DLA has static and dynamic loading capabilities up to 250N and 18N respectively, with a bandwidth sufficient to generate wind disturbances. In this paper, we present various performance requirements of SMT actuators as well as our effort to develop a dynamic loading device which can be used to test these actuators. Well before using DLA for meaningful testing of the actuator, the DLA itself have gone through various tests and improvements phases. We have successfully demonstrated that DLA can be used to check the extreme performance of two different SMT actuators, which are expected to track the position/force with a few nanometer accuracy.

Model based design of electronic throttle control

NASA Astrophysics Data System (ADS)

Cherian, Fenin; Ranjan, Ashish; Bhowmick, Pathikrit; Rammohan, A.

2017-11-01

With the advent of torque based Engine Management Systems, the precise control and robust performance of the throttle body becomes a key factor in the overall performance of the vehicle. Electronic Throttle Control provides benefits such as improved air-fuel ratio for improving the vehicle performance and lower exhausts emissions to meet the stringent emission norms. Modern vehicles facilitate various features such as Cruise Control, Traction Control, Electronic Stability Program and Pre-crash systems. These systems require control over engine power without driver intervention, which is not possible with conventional mechanical throttle system. Thus these systems are integrated to function with the electronic throttle control. However, due to inherent non-linearities in the throttle body, the control becomes a difficult task. In order to eliminate the influence of this hysteresis at the initial operation of the butterfly valve, a control to compensate the shortage must be added to the duty required for starting throttle operation when the initial operation is detected. Therefore, a lot of work is being done in this field to incorporate the various nonlinearities to achieve robust control. In our present work, the ETB was tested to verify the working of the system. Calibration of the TPS sensors was carried out in order to acquire accurate throttle opening angle. The response of the calibrated system was then plotted against a step input signal. A linear model of the ETB was prepared using Simulink and its response was compared with the experimental data to find out the initial deviation of the model from the actual system. To reduce this deviation, non-linearities from existing literature were introduced to the system and a response analysis was performed to check the deviation from the actual system. Based on this investigation, an introduction of a new nonlinearity parameter can be used in future to reduce the deviation further making the control of the ETB more precise and accurate.

Optical Breath Gas Extravehicular Activity Sensor for the Advanced Portable Life Support System

NASA Technical Reports Server (NTRS)

Wood, William R.; Casias, Miguel E.; Pilgrim, Jeffrey S.; Chullen, Cinda; Campbell, Colin

2016-01-01

The function of the infrared gas transducer used during extravehicular activity (EVA) in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires highly accurate CO2 sensing technology with performance beyond that presently in use on the International Space Station extravehicular mobility unit (EMU). Further, that accuracy needs to be provided over the full operating pressure range of the suit (3 to 25 psia). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode (LD) sensor based on infrared absorption spectroscopy is being developed for this purpose by Vista Photonics, Inc. Version 1.0 prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The prototypes were upgraded with more sophisticated communications and faster response times to version 2.0 and delivered to JSC in July 2012. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement. The prototypes are controlled digitally with an field-programmable gate array microcontroller architecture. Based on the results of the iterative instrument development, further prototype development and testing of instruments were performed leveraging the lessons learned where feasible. The present development extends and upgrades the earlier hardware for the advanced PLSS 2.5 prototypes for testing at JSC. The prototypes provide significantly enhanced accuracy for water vapor measurement and eliminate wavelength drift affecting the earlier versions. Various improvements to the electronics and gas sampling are currently being advanced including the companion development of engineering development units that will ultimately be capable of radiation tolerance. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

Student Research and Ethics: Contributing to the Debate

ERIC Educational Resources Information Center

Winder, Belinda; Brunsden, Vivienne; Farnsworth, Bill

2007-01-01

In this article, the authors comment on Hugh Foot's article on student research and ethics ["Psychology Teaching Review," 12(1), 82-86 (2006)] The authors agree with Foot that there is no case for accepting less stringent ethical criteria when the researcher is a student. However, they argue that greater attention and more stringent measures…

30 CFR 730.11 - Inconsistent and more stringent State laws and regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... regulations. 730.11 Section 730.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT... Register setting forth the text or a summary of any State law or regulation initially determined by him to... stringent land use and environmental controls and regulations of coal exploration and surface coal mining...

49 CFR 350.333 - What are the guidelines for the compatibility review?

Code of Federal Regulations, 2010 CFR

2010-10-01

... to interstate or intrastate commerce Less stringent or more stringent Action authorized (1) Yes Compatible—Interstate and intrastate commerce enforcement authorized. (2) No Intrastate Refer to § 350.341 (3... authorized if the State can demonstrate the law or regulation has a safety benefit or does not create an...

76 FR 74057 - Clean Water Act Section 303(d): Availability of List Decisions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-30

... for which existing technology-based pollution controls are not stringent enough to attain or maintain... marine criterion for dissolved oxygen was not attained in these segments. EPA is providing the public the... which existing technology-based pollution controls are not stringent enough to attain or maintain State...

Regulation of early mRNA synthesis after bacteriophage T4 infection of Escherichia coli.

PubMed Central

Linder, C H; Fast, R

1975-01-01

Regulation of T4-specific mRNA synthesis was studied during leucine starvation of a leucine-requiring stringent Escherichia coli B strain. This was done by imposing starvation prior to T4 infection and then letting RNA synthesis proceed for different time periods. Rifampin or streptolydigin was added to stop further RNA synthesis, and protein synthesis was restored by addition of leucine. Samples were withdrawn at different times, and the enzyme-forming capacities found that, during conditions which elicit the stringent response in uninfected bacteria, immediate early mRNA is not stringently regulated. This conclusion contradicts the earlier conclusion of others, obtained by measuring incorporation of radioactive uracil; this is explained by the observation of Edlin and Neuhard (1967), confirmed and extended by us to the T4-infected cell, that the incorporation of uracil into RNA of a stringent strain is virtually blocked by amino acid starvation, whereas that of adenine continues at 30 to 50% of the rate seen in the presence of the required amino acid. PMID:1099229

Modular Wireless Data-Acquisition and Control System

NASA Technical Reports Server (NTRS)

Perotti, Jose; Lucena, Angel; Medelius, Pedro; Mata, Carlos; Eckhoff, Anthony; Blalock, Norman

2004-01-01

A modular wireless data-acquisition and control system, now in operation at Kennedy Space Center, offers high performance at relatively low cost. The system includes a central station and a finite number of remote stations that communicate with each other through low-power radio frequency (RF) links. Designed to satisfy stringent requirements for reliability, integrity of data, and low power consumption, this system could be reproduced and adapted to use in a broad range of settings.

A Ten-Meter Ground-Station Telescope for Deep-Space Optical Communications: A Preliminary Design

NASA Technical Reports Server (NTRS)

Britcliffe, M.; Hoppe, D.; Roberts, W.; Page, N.

2001-01-01

This article describes a telescope design for a 10-m optical ground station for deep-space communications. The design for a direct-detection optical communications telescope differs dramatically from a telescope for imaging applications. In general, the requirements for optical manufacturing and tracking performance are much less stringent for direct detection of optical signals. The technical challenge is providing a design that will operate in the daytime/nighttime conditions required for a Deep Space Network tracking application. The design presented addresses these requirements. The design will provide higher performance at lower cost than existing designs.

Cost savings in a hospital clinical laboratory with a pay-for-performance incentive program for supervisors.

PubMed

Winkelman, J W; Aitken, J L; Wybenga, D R

1991-01-01

A pay-for-performance incentive program for clinical laboratory supervisors was developed and implemented at Brigham and Women's Hospital (Boston, Mass). It provides monetary rewards to personnel who directly produce cost savings in their area of responsibility. This reward system is new to the hospital laboratory but is commonly used in industry. Substantial true cost savings over and above previously established stringent budgets were achieved, 11% of which was returned to first-line supervisors in the form of a bonus. The program expanded the scope of professionalism for supervisors to include fiscal management.

Unregulated greenhouse gas and ammonia emissions from current technology heavy-duty vehicles.

PubMed

Thiruvengadam, Arvind; Besch, Marc; Carder, Daniel; Oshinuga, Adewale; Pasek, Randall; Hogo, Henry; Gautam, Mridul

2016-11-01

The study presents the measurement of carbonyl, BTEX (benzene, toluene, ethyl benzene, and xylene), ammonia, elemental/organic carbon (EC/OC), and greenhouse gas emissions from modern heavy-duty diesel and natural gas vehicles. Vehicles from different vocations that included goods movement, refuse trucks, and transit buses were tested on driving cycles representative of their duty cycle. The natural gas vehicle technologies included the stoichiometric engine platform equipped with a three-way catalyst and a diesel-like dual-fuel high-pressure direct-injection technology equipped with a diesel particulate filter (DPF) and a selective catalytic reduction (SCR). The diesel vehicles were equipped with a DPF and SCR. Results of the study show that the BTEX emissions were below detection limits for both diesel and natural gas vehicles, while carbonyl emissions were observed during cold start and low-temperature operations of the natural gas vehicles. Ammonia emissions of about 1 g/mile were observed from the stoichiometric natural gas vehicles equipped with TWC over all the driving cycles. The tailpipe GWP of the stoichiometric natural gas goods movement application was 7% lower than DPF and SCR equipped diesel. In the case of a refuse truck application the stoichiometric natural gas engine exhibited 22% lower GWP than a diesel vehicle. Tailpipe methane emissions contribute to less than 6% of the total GHG emissions. Modern heavy-duty diesel and natural gas engines are equipped with multiple after-treatment systems and complex control strategies aimed at meeting both the performance standards for the end user and meeting stringent U.S. Environmental Protection Agency (EPA) emissions regulation. Compared to older technology diesel and natural gas engines, modern engines and after-treatment technology have reduced unregulated emissions to levels close to detection limits. However, brief periods of inefficiencies related to low exhaust thermal energy have been shown to increase both carbonyl and nitrous oxide emissions.

Design and Performance of a Miniature Lidar Wind Profiler (MLWP)

NASA Technical Reports Server (NTRS)

Cornwell, Donald M., Jr.; Miodek, Mariusz J.

1998-01-01

The directional velocity of the wind is one of the most critical components for understanding meteorological and other dynamic atmospheric processes. Altitude-resolved wind velocity measurements, also known as wind profiles or soundings, are especially necessary for providing data for meteorological forecasting and overall global circulation models (GCM's). Wind profiler data are also critical in identifying possible dangerous weather conditions for aviation. Furthermore, a system has yet to be developed for wind profiling from the surface of Mars which could also meet the stringent requirements on size, weight, and power of such a mission. Obviously, a novel wind profiling approach based on small and efficient technology is required to meet these needs. A lidar system based on small and highly efficient semiconductor lasers is now feasible due to recent developments in the laser and detector technologies. The recent development of high detection efficiency (50%), silicon-based photon-counting detectors when combined with high laser pulse repetition rates and long receiver integration times has allowed these transmitter energies to be reduced to the order of microjoules per pulse. Aerosol lidar systems using this technique have been demonstrated for both Q-switched, diode-pumped solid-state laser transmitters (lambda = 523 nm) and semiconductor diode lasers (lambda = 830 nm); however, a wind profiling lidar based on this technique has yet to be developed. We will present an investigation of a semiconductor-laser-based lidar system which uses the "edge-filter" direct detection technique to infer Doppler frequency shifts of signals backscattered from aerosols in the planetary boundary layer (PBL). Our investigation will incorporate a novel semiconductor laser design which mitigates the deleterious effects of frequency chirp in pulsed diode lasers, a problem which has limited their use in such systems in the past. Our miniature lidar could be used on a future Mars lander and perhaps find its own niche in terrestrial applications due to its potential low cost an small size.

Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca

USGS Publications Warehouse

Besser, John M.; Ivey, Chris D.; Brumbaugh, William G.; Ingersoll, Christopher G.

2016-01-01

The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeastþcereal leafþtrout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatomsþTetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20]¼13 mg/L and 15mg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 mg/L, but these endpoints were significantly reduced by Pb in the YCT test—and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model–normalized effect concentrations for the 3 tests ranged from 3.7mg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 mg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes.

Combined Structural and Trajectory Control of Variable-Geometry Planetary Entry Systems

NASA Technical Reports Server (NTRS)

Quadrelli, Marco B.; Pellegrino, Sergio; Kwok, Kawai

2011-01-01

Some of the key challenges of planetary entry are to dissipate the large kinetic energy of the entry vehicle and to land with precision. Past missions to Mars were based on unguided entry, where entry vehicles carried payloads of less than 0.6 T and landed within 100 km of the designated target. The Mars Science Laboratory (MSL) is expected to carry a mass of almost 1 T to within 20 km of the target site. Guided lifting entry is needed to meet these higher deceleration and targeting demands. If the aerodynamic characteristics of the decelerator are variable during flight, more trajectory options are possible, and can be tailored to specific mission requirements. In addition to the entry trajectory modulation, having variable aerodynamic properties will also favor maneuvering of the vehicle prior to descent. For proper supersonic parachute deployment, the vehicle needs to turn to a lower angle of attack. One approach to entry trajectory improvement and angle of attack control is to embed a variable geometry decelerator in the design of the vehicle. Variation in geometry enables the vehicle to adjust its aerodynamic performance continuously without additional fuel cost because only electric power is needed for actuating the mechanisms that control the shape change. Novel structural and control concepts have been developed that enable the decelerator to undergo variation in geometry. Changing the aerodynamic characteristics of a flight vehicle by active means can potentially provide a mechanically simple, affordable, and enabling solution for entry, descent, and landing across a wide range of mission types, sample capture and return, and reentry to Earth, Titan, Venus, or Mars. Unguided ballistic entry is not sufficient to meet this more stringent deceleration, heating, and targeting demands. Two structural concepts for implementing the cone angle variation, a segmented shell, and a corrugated shell, have been presented.

Using self-reported callous-unemotional traits to cross-nationally assess the DSM-5 'With Limited Prosocial Emotions' specifier.

PubMed

Kimonis, Eva R; Fanti, Kostas A; Frick, Paul J; Moffitt, Terrie E; Essau, Cecilia; Bijttebier, Patricia; Marsee, Monica A

2015-11-01

The presence of callous-unemotional (CU) traits designates an important subgroup of antisocial youth at risk for severe, persistent, and impairing conduct problems. As a result, the fifth revision of the Diagnostic and Statistical Manual includes a specifier for youth meeting diagnostic criteria for Conduct Disorder who show elevated CU traits. The current study evaluated the DSM-5 criteria using Item Response Theory (IRT) analyses and evaluated two methods for using a self-report measure of CU traits to make this diagnosis. The sample included 2257 adolescent (M age = 15.64, SD = 1.69 years) boys (53%) and girls (47%) from community and incarcerated settings in the United States and the European countries of Belgium, Germany, and Cyprus. IRT analyses suggested that four- or eight-item sets from the self-report measure (comparable to the symptoms used by the DSM-5 specifier) provided good model fit, suggesting that they assess a single underlying CU construct. Further, the most stringent method of scoring the self-report scale (i.e. taking only the most extreme responses) to approximate symptom presence provided the best discrimination in IRT analyses, showed reasonable prevalence rates of the specifier, and designated community adolescents who were highly antisocial, whereas the less stringent method best discriminated detained youth. Refined self-report scales developed on the basis of IRT findings provided good assessments of most of the symptoms used in the DSM-5 criteria. These scales may be used as one component of a multimethod assessment of the 'With Limited Prosocial Emotions' specifier for Conduct Disorder. © 2014 Association for Child and Adolescent Mental Health.

Evidence for somatic gene conversion and deletion in bipolar disorder, Crohn's disease, coronary artery disease, hypertension, rheumatoid arthritis, type-1 diabetes, and type-2 diabetes

PubMed Central

2011-01-01

Background During gene conversion, genetic information is transferred unidirectionally between highly homologous but non-allelic regions of DNA. While germ-line gene conversion has been implicated in the pathogenesis of some diseases, somatic gene conversion has remained technically difficult to investigate on a large scale. Methods A novel analysis technique is proposed for detecting the signature of somatic gene conversion from SNP microarray data. The Wellcome Trust Case Control Consortium has gathered SNP microarray data for two control populations and cohorts for bipolar disorder (BD), cardiovascular disease (CAD), Crohn's disease (CD), hypertension (HT), rheumatoid arthritis (RA), type-1 diabetes (T1D) and type-2 diabetes (T2D). Using the new analysis technique, the seven disease cohorts are analyzed to identify cohort-specific SNPs at which conversion is predicted. The quality of the predictions is assessed by identifying known disease associations for genes in the homologous duplicons, and comparing the frequency of such associations with background rates. Results Of 28 disease/locus pairs meeting stringent conditions, 22 show various degrees of disease association, compared with only 8 of 70 in a mock study designed to measure the background association rate (P < 10-9). Additional candidate genes are identified using less stringent filtering conditions. In some cases, somatic deletions appear likely. RA has a distinctive pattern of events relative to other diseases. Similarities in patterns are apparent between BD and HT. Conclusions The associations derived represent the first evidence that somatic gene conversion could be a significant causative factor in each of the seven diseases. The specific genes provide potential insights about disease mechanisms, and are strong candidates for further study. Please see Commentary: http://www.biomedcentral.com/1741-7015/9/13/abstract. PMID:21291537

Evidence for somatic gene conversion and deletion in bipolar disorder, Crohn's disease, coronary artery disease, hypertension, rheumatoid arthritis, type-1 diabetes, and type-2 diabetes.

PubMed

Ross, Kenneth Andrew

2011-02-03

During gene conversion, genetic information is transferred unidirectionally between highly homologous but non-allelic regions of DNA. While germ-line gene conversion has been implicated in the pathogenesis of some diseases, somatic gene conversion has remained technically difficult to investigate on a large scale. A novel analysis technique is proposed for detecting the signature of somatic gene conversion from SNP microarray data. The Wellcome Trust Case Control Consortium has gathered SNP microarray data for two control populations and cohorts for bipolar disorder (BD), cardiovascular disease (CAD), Crohn's disease (CD), hypertension (HT), rheumatoid arthritis (RA), type-1 diabetes (T1D) and type-2 diabetes (T2D). Using the new analysis technique, the seven disease cohorts are analyzed to identify cohort-specific SNPs at which conversion is predicted. The quality of the predictions is assessed by identifying known disease associations for genes in the homologous duplicons, and comparing the frequency of such associations with background rates. Of 28 disease/locus pairs meeting stringent conditions, 22 show various degrees of disease association, compared with only 8 of 70 in a mock study designed to measure the background association rate (P < 10-9). Additional candidate genes are identified using less stringent filtering conditions. In some cases, somatic deletions appear likely. RA has a distinctive pattern of events relative to other diseases. Similarities in patterns are apparent between BD and HT. The associations derived represent the first evidence that somatic gene conversion could be a significant causative factor in each of the seven diseases. The specific genes provide potential insights about disease mechanisms, and are strong candidates for further study.

Precision growth index using the clustering of cosmic structures and growth data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pouri, Athina; Basilakos, Spyros; Plionis, Manolis, E-mail: athpouri@phys.uoa.gr, E-mail: svasil@academyofathens.gr, E-mail: mplionis@physics.auth.gr

2014-08-01

We use the clustering properties of Luminous Red Galaxies (LRGs) and the growth rate data provided by the various galaxy surveys in order to constrain the growth index γ) of the linear matter fluctuations. We perform a standard χ{sup 2}-minimization procedure between theoretical expectations and data, followed by a joint likelihood analysis and we find a value of γ=0.56± 0.05, perfectly consistent with the expectations of the ΛCDM model, and Ω{sub m0} =0.29± 0.01, in very good agreement with the latest Planck results. Our analysis provides significantly more stringent growth index constraints with respect to previous studies, as indicated by the fact thatmore » the corresponding uncertainty is only ∼ 0.09 γ. Finally, allowing γ to vary with redshift in two manners (Taylor expansion around z=0, and Taylor expansion around the scale factor), we find that the combined statistical analysis between our clustering and literature growth data alleviates the degeneracy and obtain more stringent constraints with respect to other recent studies.« less

Theory and design of interferometric synthetic aperture radars

NASA Technical Reports Server (NTRS)

Rodriguez, E.; Martin, J. M.

1992-01-01

A derivation of the signal statistics, an optimal estimator of the interferometric phase, and the expression necessary to calculate the height-error budget are presented. These expressions are used to derive methods of optimizing the parameters of the interferometric synthetic aperture radar system (InSAR), and are then employed in a specific design example for a system to perform high-resolution global topographic mapping with a one-year mission lifetime, subject to current technological constraints. A Monte Carlo simulation of this InSAR system is performed to evaluate its performance for realistic topography. The results indicate that this system has the potential to satisfy the stringent accuracy and resolution requirements for geophysical use of global topographic data.

Responding to hypnotic and nonhypnotic suggestions: performance standards, imaginative suggestibility, and response expectancies.

PubMed

Meyer, Eric C; Lynn, Steven Jay

2011-07-01

This study examined the relative impact of hypnotic inductions and several other variables on hypnotic and nonhypnotic responsiveness to imaginative suggestions. The authors examined how imaginative suggestibility, response expectancies, motivation to respond to suggestions, and hypnotist-induced performance standards affected participants' responses to both hypnotic and nonhypnotic suggestions and their suggestion-related experiences. Suggestions were administered to 5 groups of participants using a test-retest design: (a) stringent performance standards; (b) lenient performance standards; (c) hypnosis test-retest; (d) no-hypnosis test-retest; and (e) no-hypnosis/hypnosis control. The authors found no support for the influence of a hypnotic induction or performance standards on responding to suggestions but found considerable support for the role of imaginative suggestibility and response expectancies in predicting responses to both hypnotic and nonhypnotic suggestions.

Feedback System Theory

DTIC Science & Technology

1978-11-01

R 2. GOVT A $ SION NO. 3 RIEqLPýIVT’S.;TALOG NUMBER r/ 4. TITLE (and wbiFflT, -L M4 1 , FEEDBACK SYSTEM THEORY ~r Inter in- 6. PERFORMING ORG. REPORT...ANNUAL REPORT FEEDBACK SYSTEM THEORY AFOSR GRANT NO. 76-2946B Air Force Office of Scientific Research for year ending October 31, 1978 79 02 08 L|I...re less stringent than in other synthesis techniques which cannot handle significant parameter uncertainty. _I FEEDBACK SYSTEM THEORY 1. Introduction

Hubble Space Telescope servicing mission scientific instrument protective enclosure design requirements and contamination controls

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.; Hughes, David W.; Hedgeland, Randy J.; Chivatero, Craig J.; Studer, Robert J.; Kostos, Peter J.

1994-01-01

The Scientific Instrument Protective Enclosures were designed for the Hubble Space Telescope Servicing Missions to provide a beginning environment to a Scientific Instrument during ground and on orbit activities. The Scientific Instruments required very stringent surface cleanliness and molecular outgassing levels to maintain ultraviolet performance. Data from the First Servicing Mission verified that both the Scientific Instruments and Scientific Instrument Protective Enclosures met surface cleanliness level requirements during ground and on-orbit activities.

Lube oil-dependent ash chemistry on soot oxidation reactivity in a gasoline direct-injection engine

DOE PAGES

Choi, Seungmok; Seong, Heeje

2016-09-30

Gasoline particulate filters (GPF) are considered an enabling technology to meet stringent particulate matter (PM) regulations for gasoline direct-injection (GDI) engines, which are known to produce significant PM emissions. While ash loading in filters has been recognized to be detrimental in filter performance by increasing back pressure, increased ash fractions in soot were observed to enhance soot oxidation. In this study, GDI soot samples derived from different gasoline/lube oil blends were evaluated to identify potential promoting factors when formulated lube oils were dosed into gasoline fuel. Ca-derived ash enhanced soot oxidation remarkably, while P- and ZDDP-derived ash deteriorated soot oxidation.more » It is apparent that the promoting effect of lube oil-derived ash is due mainly to the Ca component that is the most abundant among additive components in lube oil. Bulk and surface analyses of these ash compounds indicate that Ca-derived ash would be complex compounds, while the contribution of CaSO 4, which is one of the most abundant ash compounds from diesel engines, is almost negligible. For the validation of the ash promoting impact in filters, the regeneration experiments were compared for a TWC-coated GPF in a GDI engine before and after ash loading was performed. The pressure drop of the ash-loaded GPF decreased noticeably in the initial regeneration stage and it increased gradually, whereas that of no ash-loaded GPF increased gradually without any reduction. So, it is concluded that the ash layer in the GPF assisted soot oxidation in the early regeneration stage when it was in close contact with soot.« less

Desorption electrospray ionization mass spectrometry for trace analysis of agrochemicals in food.

PubMed

García-Reyes, Juan F; Jackson, Ayanna U; Molina-Díaz, Antonio; Cooks, R Graham

2009-01-15

Desorption electrospray ionization (DESI) is applied to the rapid, in situ, direct qualitative and quantitative (ultra)trace analysis of agrochemicals in foodstuffs. To evaluate the potential of DESI mass spectrometry (MS) in toxic residue testing in food, 16 representative multiclass agricultural chemicals (pesticides, insecticides, herbicides, and fungicides) were selected (namely, ametryn, amitraz, azoxystrobin, bitertanol, buprofezin, imazalil, imazalil metabolite, isofenphos-methyl, malathion, nitenpyram, prochloraz, spinosad, terbuthylazine, thiabendazole, and thiacloprid). The DESI-MS experiments were performed using 3 microL of solution spotted onto conventional smooth poly(tetrafluoroethylene) (PTFE) surfaces, with examination by MS and tandem mass spectrometry (MS/MS) using an ion trap mass spectrometer. Optimization of the spray solvent led to the use of acetonitrile/water (80:20) (v/v), with 1% formic acid. Most of the compounds tested showed remarkable sensitivity in the positive ion mode, approaching that attainable with conventional direct infusion electrospray mass spectrometry. To evaluate the potential of the proposed approach in real samples, different experiments were performed including the direct DESI-MS/MS analysis of fruit peels and also of fruit/vegetable extracts. The results proved that DESI allows the detection and confirmation of traces of agrochemicals in actual market-purchased samples. In addition, MS/MS confirmation of selected pesticides in spiked vegetable extracts was obtained at absolute levels as low as 1 pg for ametryn. Quantitation of imazalil residues was also undertaken using an isotopically labeled standard. The data obtained were in agreement with those from the liquid chromatography mass spectrometry (LC-MS) reference method, with relative standard deviation (RSD) values consistently below 15%. The results obtained demonstrate the sensitivity of DESI as they meet the stringent European Union pesticide regulation requirements (maximum residue levels) for a large percentage of the studied compounds.

Lube oil-dependent ash chemistry on soot oxidation reactivity in a gasoline direct-injection engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seungmok; Seong, Heeje

Gasoline particulate filters (GPF) are considered an enabling technology to meet stringent particulate matter (PM) regulations for gasoline direct-injection (GDI) engines, which are known to produce significant PM emissions. While ash loading in filters has been recognized to be detrimental in filter performance by increasing back pressure, increased ash fractions in soot were observed to enhance soot oxidation. In this study, GDI soot samples derived from different gasoline/lube oil blends were evaluated to identify potential promoting factors when formulated lube oils were dosed into gasoline fuel. Ca-derived ash enhanced soot oxidation remarkably, while P- and ZDDP-derived ash deteriorated soot oxidation.more » It is apparent that the promoting effect of lube oil-derived ash is due mainly to the Ca component that is the most abundant among additive components in lube oil. Bulk and surface analyses of these ash compounds indicate that Ca-derived ash would be complex compounds, while the contribution of CaSO 4, which is one of the most abundant ash compounds from diesel engines, is almost negligible. For the validation of the ash promoting impact in filters, the regeneration experiments were compared for a TWC-coated GPF in a GDI engine before and after ash loading was performed. The pressure drop of the ash-loaded GPF decreased noticeably in the initial regeneration stage and it increased gradually, whereas that of no ash-loaded GPF increased gradually without any reduction. So, it is concluded that the ash layer in the GPF assisted soot oxidation in the early regeneration stage when it was in close contact with soot.« less

33 CFR 154.1045 - Response plan development and evaluation criteria for facilities that handle, store, or transport...

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Reclassifications may be to— (i) A more stringent operating environment if the prevailing wave conditions exceed the significant wave height criteria during more than 35 percent of the year; or (ii) A less stringent operating environment if the prevailing wave conditions do not exceed the significant wave height criteria for the less...

Size ratio performance in detecting cerebral aneurysm rupture status is insensitive to small vessel removal.

PubMed

Lauric, Alexandra; Baharoglu, Merih I; Malek, Adel M

2013-04-01

The variable definition of size ratio (SR) for sidewall (SW) vs bifurcation (BIF) aneurysms raises confusion for lesions harboring small branches, such as carotid ophthalmic or posterior communicating locations. These aneurysms are considered SW by many clinicians, but SR methodology classifies them as BIF. To evaluate the effect of ignoring small vessels and SW vs stringent BIF labeling on SR ruptured aneurysm detection performance in borderline aneurysms with small branches, and to reconcile SR-based labeling with clinical SW/BIF classification. Catheter rotational angiographic datasets of 134 consecutive aneurysms (60 ruptured) were automatically measured in 3-dimensional. Stringent BIF labeling was applied to clinically labeled aneurysms, with 21 aneurysms switching label from SW to BIF. Parent vessel size was evaluated both taking into account, and ignoring, small vessels. SR was defined accordingly as the ratio between aneurysm and parent vessel sizes. Univariate and multivariate statistics identified significant features. The square of the correlation coefficient (R(2)) was reported for bivariate analysis of alternative SR calculations. Regardless of SW/BIF labeling method, SR was equally significant in discriminating aneurysm ruptured status (P < .001). Bivariate analysis of alternative SR had a high correlation of R(2) = 0.94 on the whole dataset, and R = 0.98 on the 21 borderline aneurysms. Ignoring small branches from SR calculation maintains rupture status detection performance, while reducing postprocessing complexity and removing labeling ambiguity. Aneurysms adjacent to these vessels can be considered SW for morphometric analysis. It is reasonable to use the clinical SW/BIF labeling when using SR for rupture risk evaluation.

Feasibility of magnetic resonance imaging-guided liver stereotactic body radiation therapy: A comparison between modulated tri-cobalt-60 teletherapy and linear accelerator-based intensity modulated radiation therapy.

PubMed

Kishan, Amar U; Cao, Minsong; Wang, Pin-Chieh; Mikaeilian, Argin G; Tenn, Stephen; Rwigema, Jean-Claude M; Sheng, Ke; Low, Daniel A; Kupelian, Patrick A; Steinberg, Michael L; Lee, Percy

2015-01-01

The purpose of this study was to investigate the dosimetric feasibility of liver stereotactic body radiation therapy (SBRT) using a teletherapy system equipped with 3 rotating (60)Co sources (tri-(60)Co system) and a built-in magnetic resonance imager (MRI). We hypothesized tumor size and location would be predictive of favorable dosimetry with tri-(60)Co SBRT. The primary study population consisted of 11 patients treated with SBRT for malignant hepatic lesions whose linear accelerator (LINAC)-based SBRT plans met all mandatory Radiation Therapy Oncology Group (RTOG) 1112 organ-at-risk (OAR) constraints. The secondary study population included 5 additional patients whose plans did not meet the mandatory constraints. Patients received 36 to 60 Gy in 3 to 5 fractions. Tri-(60)Co system SBRT plans were planned with ViewRay system software. All patients in the primary study population had tri-(60)Co SBRT plans that passed all RTOG constraints, with similar planning target volume coverage and OAR doses to LINAC plans. Mean liver doses and V10Gy to the liver, although easily meeting RTOG 1112 guidelines, were significantly higher with tri-(60)Co plans. When the 5 additional patients were included in a univariate analysis, the tri-(60)Co SBRT plans were still equally able to pass RTOG constraints, although they did have inferior ability to pass more stringent liver and kidney constraints (P < .05). A multivariate analysis found the ability of a tri-(60)Co SBRT plan to meet these constraints depended on lesion location and size. Patients with smaller or more peripheral lesions (as defined by distance from the aorta, chest wall, liver dome, and relative lesion volume) were significantly more likely to have tri-(60)Co plans that spared the liver and kidney as well as LINAC plans did (P < .05). It is dosimetrically feasible to perform liver SBRT with a tri-(60)Co system with a built-in MRI. Patients with smaller or more peripheral lesions are more likely to have optimal liver and kidney sparing, with the added benefit of MRI guidance, when receiving tri-(60)Co-based SBRT. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Robust Fixed-Structure Controller Synthesis

NASA Technical Reports Server (NTRS)

Corrado, Joseph R.; Haddad, Wassim M.; Gupta, Kajal (Technical Monitor)

2000-01-01

The ability to develop an integrated control system design methodology for robust high performance controllers satisfying multiple design criteria and real world hardware constraints constitutes a challenging task. The increasingly stringent performance specifications required for controlling such systems necessitates a trade-off between controller complexity and robustness. The principle challenge of the minimal complexity robust control design is to arrive at a tractable control design formulation in spite of the extreme complexity of such systems. Hence, design of minimal complexitY robust controllers for systems in the face of modeling errors has been a major preoccupation of system and control theorists and practitioners for the past several decades.

Nocturnality constrains morphological and functional diversity in the eyes of reef fishes.

PubMed

Schmitz, Lars; Wainwright, Peter C

2011-11-19

Ambient light levels are often considered to drive the evolution of eye form and function. Diel activity pattern is the main mechanism controlling the visual environment of teleost reef fish, with day-active (diurnal) fish active in well-illuminated conditions, whereas night-active (nocturnal) fish cope with dim light. Physiological optics predicts several specific evolutionary responses to dim-light vision that should be reflected in visual performance features of the eye. We analyzed a large comparative dataset on morphological traits of the eyes in 265 species of teleost reef fish in 43 different families. The eye morphology of nocturnal reef teleosts is characterized by a syndrome that indicates better light sensitivity, including large relative eye size, high optical ratio and large, rounded pupils. Improved dim-light image formation comes at the cost of reduced depth of focus and reduction of potential accommodative lens movement. Diurnal teleost reef fish, released from the stringent functional requirements of dim-light vision have much higher morphological and optical diversity than nocturnal species, with large ranges of optical ratio, depth of focus, and lens accommodation. Physical characteristics of the environment are an important factor in the evolution and diversification of the vertebrate eye. Both teleost reef fish and terrestrial amniotes meet the functional requirements of dim-light vision with a similar evolutionary response of morphological and optical modifications. The trade-off between improved dim-light vision and reduced optical diversity may be a key factor in explaining the lower trophic diversity of nocturnal reef teleosts.

Aerodynamic Decelerators for Planetary Exploration: Past, Present, and Future

NASA Technical Reports Server (NTRS)

Cruz, Juna R.; Lingard, J. Stephen

2006-01-01

In this paper, aerodynamic decelerators are defined as textile devices intended to be deployed at Mach numbers below five. Such aerodynamic decelerators include parachutes and inflatable aerodynamic decelerators (often known as ballutes). Aerodynamic decelerators play a key role in the Entry, Descent, and Landing (EDL) of planetary exploration vehicles. Among the functions performed by aerodynamic decelerators for such vehicles are deceleration (often from supersonic to subsonic speeds), minimization of descent rate, providing specific descent rates (so that scientific measurements can be obtained), providing stability (drogue function - either to prevent aeroshell tumbling or to meet instrumentation requirements), effecting further aerodynamic decelerator system deployment (pilot function), providing differences in ballistic coefficients of components to enable separation events, and providing height and timeline to allow for completion of the EDL sequence. Challenging aspects in the development of aerodynamic decelerators for planetary exploration missions include: deployment in the unusual combination of high Mach numbers and low dynamic pressures, deployment in the wake behind a blunt-body entry vehicle, stringent mass and volume constraints, and the requirement for high drag and stability. Furthermore, these aerodynamic decelerators must be qualified for flight without access to the exotic operating environment where they are expected to operate. This paper is an introduction to the development and application of aerodynamic decelerators for robotic planetary exploration missions (including Earth sample return missions) from the earliest work in the 1960s to new ideas and technologies with possible application to future missions. An extensive list of references is provided for additional study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Storey, John Morse; Lewis Sr, Samuel Arthur; Szybist, James P

Gasoline direct injection (GDI) engines can offer improved fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet more stringent fuel economy standards. GDI engines typically emit the most particulate matter (PM) during periods of rich operation such as start-up and acceleration, and emissions of air toxics are also more likely during this condition. A 2.0 L GDI engine was operated at lambda ofmore » 0.91 at typical loads for acceleration (2600 rpm, 8 bar BMEP) on three different fuels; an 87 anti-knock index (AKI) gasoline (E0), 30% ethanol blended with the 87 AKI fuel (E30), and 48% isobutanol blended with the 87 AKI fuel. E30 was chosen to maximize octane enhancement while minimizing ethanol-blend level and iBu48 was chosen to match the same fuel oxygen level as E30. Particle size and number, organic carbon and elemental carbon (OC/EC), soot HC speciation, and aldehydes and ketones were all analyzed during the experiment. A new method for soot HC speciation is introduced using a direct, thermal desorption/pyrolysis inlet for the gas chromatograph (GC). Results showed high levels of aromatic compounds were present in the PM, including downstream of the catalyst, and the aldehydes were dominated by the alcohol blending.« less

Essentials of the disclosure review process: a federal perspective.

PubMed

Zarate, Alvan O; Zayatz, Laura

2006-09-01

MANY RESEARCHERS NEED TO MAKE arrangements to share de-identified electronic data files. However, the ways in which respondent identity may be protected are not well understood or are assumed to be the special province of large statistical agencies or specialized statisticians. Approaches to data sharing and protecting respondent identity have been pioneered by federal agencies which gather data vital to political and economic decision making. These agencies are required by statutory law both to assure confidentiality and to share data in usable form with other governmental agencies and with scholars who perform needed analyses of those data. The basic principles of disclosure limitation developed by the Census Bureau, the National Center for Health Statistics, and other federal agencies are fundamental to meeting new funding requirements to share and deidentify data, and are often referred to in the literature on data sharing. We describe how these principles are employed by the Disclosure Review Boards (DRBs) of these two agencies, and then state these principles in more general terms that are applicable to any disclosure review process. The kinds of data that academic institutions share may call for less complex or stringent DRBs and specific nondisclosure procedures different from those employed by federal agencies, but the same general principles apply. Specific application of these six principles by non-government researchers will depend on the nature of their data, their own institutional resources, and the likely future usefulness of their data.

An embedded barcode for "connected" malaria rapid diagnostic tests.

PubMed

Scherr, Thomas F; Gupta, Sparsh; Wright, David W; Haselton, Frederick R

2017-03-29

Many countries are shifting their efforts from malaria control to disease elimination. New technologies will be necessary to meet the more stringent demands of elimination campaigns, including improved quality control of malaria diagnostic tests, as well as an improved means for communicating test results among field healthcare workers, test manufacturers, and national ministries of health. In this report, we describe and evaluate an embedded barcode within standard rapid diagnostic tests as one potential solution. This information-augmented diagnostic test operates on the familiar principles of traditional lateral flow assays and simply replaces the control line with a control grid patterned in the shape of a QR (quick response) code. After the test is processed, the QR code appears on both positive or negative tests. In this report we demonstrate how this multipurpose code can be used not only to fulfill the control line role of test validation, but also to embed test manufacturing details, serve as a trigger for image capture, enable registration for image analysis, and correct for lighting effects. An accompanying mobile phone application automatically captures an image of the test when the QR code is recognized, decodes the QR code, performs image processing to determine the concentration of the malarial biomarker histidine-rich protein 2 at the test line, and transmits the test results and QR code payload to a secure web portal. This approach blends automated, sub-nanomolar biomarker detection, with near real-time reporting to provide quality assurance data that will help to achieve malaria elimination.

Engine Validation of Noise and Emission Reduction Technology Phase I

NASA Technical Reports Server (NTRS)

Weir, Don (Editor)

2008-01-01

This final report has been prepared by Honeywell Aerospace, Phoenix, Arizona, a unit of Honeywell International, Inc., documenting work performed during the period December 2004 through August 2007 for the NASA Glenn Research Center, Cleveland, Ohio, under the Revolutionary Aero-Space Engine Research (RASER) Program, Contract No. NAS3-01136, Task Order 8, Engine Validation of Noise and Emission Reduction Technology Phase I. The NASA Task Manager was Dr. Joe Grady of the NASA Glenn Research Center. The NASA Contract Officer was Mr. Albert Spence of the NASA Glenn Research Center. This report is for a test program in which NASA funded engine validations of integrated technologies that reduce aircraft engine noise. These technologies address the reduction of engine fan and jet noise, and noise associated with propulsion/airframe integration. The results of these tests will be used by NASA to identify the engineering tradeoffs associated with the technologies that are needed to enable advanced engine systems to meet stringent goals for the reduction of noise. The objectives of this program are to (1) conduct system engineering and integration efforts to define the engine test-bed configuration; (2) develop selected noise reduction technologies to a technical maturity sufficient to enable engine testing and validation of those technologies in the FY06-07 time frame; (3) conduct engine tests designed to gain insight into the sources, mechanisms and characteristics of noise in the engines; and (4) establish baseline engine noise measurements for subsequent use in the evaluation of noise reduction.

Dual Regulation of Bacillus subtilis kinB Gene Encoding a Sporulation Trigger by SinR through Transcription Repression and Positive Stringent Transcription Control.

PubMed

Fujita, Yasutaro; Ogura, Mitsuo; Nii, Satomi; Hirooka, Kazutake

2017-01-01

It is known that transcription of kinB encoding a trigger for Bacillus subtilis sporulation is under repression by SinR, a master repressor of biofilm formation, and under positive stringent transcription control depending on the adenine species at the transcription initiation nucleotide (nt). Deletion and base substitution analyses of the kinB promoter (P kinB ) region using lacZ fusions indicated that either a 5-nt deletion (Δ5, nt -61/-57, +1 is the transcription initiation nt) or the substitution of G at nt -45 with A (G-45A) relieved kinB repression. Thus, we found a pair of SinR-binding consensus sequences (GTTCTYT; Y is T or C) in an inverted orientation (SinR-1) between nt -57/-42, which is most likely a SinR-binding site for kinB repression. This relief from SinR repression likely requires SinI, an antagonist of SinR. Surprisingly, we found that SinR is essential for positive stringent transcription control of P kinB . Electrophoretic mobility shift assay (EMSA) analysis indicated that SinR bound not only to SinR-1 but also to SinR-2 (nt -29/-8) consisting of another pair of SinR consensus sequences in a tandem repeat arrangement; the two sequences partially overlap the '-35' and '-10' regions of P kinB . Introduction of base substitutions (T-27C C-26T) in the upstream consensus sequence of SinR-2 affected positive stringent transcription control of P kinB , suggesting that SinR binding to SinR-2 likely causes this positive control. EMSA also implied that RNA polymerase and SinR are possibly bound together to SinR-2 to form a transcription initiation complex for kinB transcription. Thus, it was suggested in this work that derepression of kinB from SinR repression by SinI induced by Spo0A∼P and occurrence of SinR-dependent positive stringent transcription control of kinB might induce effective sporulation cooperatively, implying an intimate interplay by stringent response, sporulation, and biofilm formation.

SS/RCS surface tension propellant acquisition/expulsion tankage technology

NASA Technical Reports Server (NTRS)

1975-01-01

The analysis, design, fabrication, and testing of a propellant tank that satisfies the requirements of the space shuttle is presented. This mission presents very stringent and sometimes conflicting requirements. A compartmented-tank device was developed and various ground and drop tower test techniques were employed to verify the design using both subscale and full-scale hardware. Performance was established with scale models and further substantiation was obtained with the full-scale tankage. Fabrication, acceptance, fill and drain, inspection, and other ground handling procedures were developed.

Global Rsh-dependent transcription profile of Brucella suis during stringent response unravels adaptation to nutrient starvation and cross-talk with other stress responses

PubMed Central

2013-01-01

Background In the intracellular pathogen Brucella spp., the activation of the stringent response, a global regulatory network providing rapid adaptation to growth-affecting stress conditions such as nutrient deficiency, is essential for replication in the host. A single, bi-functional enzyme Rsh catalyzes synthesis and hydrolysis of the alarmone (p)ppGpp, responsible for differential gene expression under stringent conditions. Results cDNA microarray analysis allowed characterization of the transcriptional profiles of the B. suis 1330 wild-type and Δrsh mutant in a minimal medium, partially mimicking the nutrient-poor intramacrophagic environment. A total of 379 genes (11.6% of the genome) were differentially expressed in a rsh-dependent manner, of which 198 were up-, and 181 were down-regulated. The pleiotropic character of the response was confirmed, as the genes encoded an important number of transcriptional regulators, cell envelope proteins, stress factors, transport systems, and energy metabolism proteins. Virulence genes such as narG and sodC, respectively encoding respiratory nitrate reductase and superoxide dismutase, were under the positive control of (p)ppGpp, as well as expression of the cbb3-type cytochrome c oxidase, essential for chronic murine infection. Methionine was the only amino acid whose biosynthesis was absolutely dependent on stringent response in B. suis. Conclusions The study illustrated the complexity of the processes involved in adaptation to nutrient starvation, and contributed to a better understanding of the correlation between stringent response and Brucella virulence. Most interestingly, it clearly indicated (p)ppGpp-dependent cross-talk between at least three stress responses playing a central role in Brucella adaptation to the host: nutrient, oxidative, and low-oxygen stress. PMID:23834488

3D Integration for Wireless Multimedia

NASA Astrophysics Data System (ADS)

Kimmich, Georg

The convergence of mobile phone, internet, mapping, gaming and office automation tools with high quality video and still imaging capture capability is becoming a strong market trend for portable devices. High-density video encode and decode, 3D graphics for gaming, increased application-software complexity and ultra-high-bandwidth 4G modem technologies are driving the CPU performance and memory bandwidth requirements close to the PC segment. These portable multimedia devices are battery operated, which requires the deployment of new low-power-optimized silicon process technologies and ultra-low-power design techniques at system, architecture and device level. Mobile devices also need to comply with stringent silicon-area and package-volume constraints. As for all consumer devices, low production cost and fast time-to-volume production is key for success. This chapter shows how 3D architectures can bring a possible breakthrough to meet the conflicting power, performance and area constraints. Multiple 3D die-stacking partitioning strategies are described and analyzed on their potential to improve the overall system power, performance and cost for specific application scenarios. Requirements and maturity of the basic process-technology bricks including through-silicon via (TSV) and die-to-die attachment techniques are reviewed. Finally, we highlight new challenges which will arise with 3D stacking and an outlook on how they may be addressed: Higher power density will require thermal design considerations, new EDA tools will need to be developed to cope with the integration of heterogeneous technologies and to guarantee signal and power integrity across the die stack. The silicon/wafer test strategies have to be adapted to handle high-density IO arrays, ultra-thin wafers and provide built-in self-test of attached memories. New standards and business models have to be developed to allow cost-efficient assembly and testing of devices from different silicon and technology providers.

Long-wavelength photonic integrated circuits and avalanche photodetectors

NASA Astrophysics Data System (ADS)

Tsou, Yi-Jen D.; Zaytsev, Sergey; Pauchard, Alexandre; Hummel, Steve; Lo, Yu-Hwa

2001-10-01

Fast-growing internet traffic volume require high data communication bandwidth over longer distances. Access network bottlenecks put pressure on short-range (SR) telecommunication systems. To effectively address these datacom and telecom market needs, low-cost, high-speed laser modules at 1310 to 1550 nm wavelengths and avalanche photodetectors are required. The great success of GaAs 850nm VCSEls for Gb/s Ethernet has motivated efforts to extend VCSEL technology to longer wavelengths in the 1310 and 1550 nm regimes. However, the technological challenges associated with materials for long wavelength VCSELs are tremendous. Even with recent advances in this area, it is believed that significant additional development is necessary before long wavelength VCSELs that meet commercial specifications will be widely available. In addition, the more stringent OC192 and OC768 specifications for single-mode fiber (SMF) datacom may require more than just a long wavelength laser diode, VCSEL or not, to address numerous cost and performance issues. We believe that photonic integrated circuits (PICs), which compactly integrate surface-emitting lasers with additional active and passive optical components with extended functionality, will provide the best solutions to today's problems. Photonic integrated circuits have been investigated for more than a decade. However, they have produced limited commercial impact to date primarily because the highly complicated fabrication processes produce significant yield and device performance issues. In this presentation, we will discuss a new technology platform of InP-based PICs compatible with surface-emitting laser technology, as well as a high data rate externally modulated laser module. Avalanche photodetectors (APDs) are the key component in the receiver to achieve high data rate over long transmission distance because of their high sensitivity and large gain- bandwidth product. We have used wafer fusion technology to achieve InGaAs/Si APDs with much greater potential than the traditional InGaAs/InP APDs. Preliminary results on their performance will be presented.

Do family physicians electronic health records support meaningful use?

PubMed

Peterson, Lars E; Blackburn, Brenna; Ivins, Douglas; Mitchell, Jason; Matson, Christine; Phillips, Robert L

2015-03-01

Spurred by government incentives, the use of electronic health records (EHRs) in the United States has increased; however, whether these EHRs have the functionality necessary to meet meaningful use (MU) criteria remains unknown. Our objective was to characterize family physician access to MU functionality when using a MU-certified EHR. Data were obtained from a convenience survey of family physicians accessing their American Board of Family Medicine online portfolio in 2011. A brief survey queried MU functionality. We used descriptive statistics to characterize the responses and bivariate statistics to test associations between MU and patient communication functions by presence of a MU-certified EHR. Out of 3855 respondents, 60% reported having an EHR that supports MU. Physicians with MU-certified EHRs were more likely than physicians without MU-certified EHRs to report patient registry activities (49.7% vs. 32.3%, p-value<0.01), tracking quality measures (74.1% vs. 56.4%, p-value<0.01), access to labs or consultation notes, and electronic prescribing; but electronic communication abilities were low regardless of EHR capabilities. Family physicians with MU-certified EHRs are more likely to report MU functionality; however, a sizeable minority does not report MU functions. Many family physicians with MU-certified EHRs may not successfully meet the successively stringent MU criteria and may face significant upgrade costs to do so. Cross sectional survey. Copyright © 2014 Elsevier Inc. All rights reserved.

DEMONSTRATION OF POTENTIAL FOR SELECTIVE CATALYTIC REDUCTION AND DIESEL PARTICULATE FILTERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGILL,R; KHAIR, M; SHARP, C

2003-08-24

This project addresses the potential for Selective Catalytic Reduction (SCR) devices (using urea as reductant) together with Diesel Particulate Filters (DPF) and low-pressure loop exhaust gas recirculation (EGR) to achieve future stringent emissions standards for heavy-duty engines powering Class 8 vehicles. Two emission control systems consisting of the three technologies (EGR, SCR, and DPF) were calibrated on a Caterpillar C-12 heavy-duty diesel engine. Results of these calibrations showed good promise in meeting the 2010 heavy-duty emission standards as set forth by the Environmental Protection Agency (EPA). These two emission control systems were developed to evaluate a series of fuels thatmore » have similar formulations except for their sulfur content. Additionally, one fuel, code-named BP15, was also evaluated. This fuel was prepared by processing straight-run distillate stocks through a commercial, single stage hydrotreater employing high activity catalyst at maximum severity. An additional goal of this program is to provide data for an on-going EPA technology review that evaluates progress toward meeting 2007/2010 emission standards. These emissions levels were to be achieved not only on the transient test cycles but in other modes of operation such as the steady-state Euro-III style emission test known as the OICA (Organisation Internationale des Compagnies d'Automobiles) or the ESC (European Stationary Cycle). Additionally, hydrocarbon and carbon monoxide emissions standards are to be met.« less

Intelligent redundant actuation system requirements and preliminary system design

NASA Technical Reports Server (NTRS)

Defeo, P.; Geiger, L. J.; Harris, J.

1985-01-01

Several redundant actuation system configurations were designed and demonstrated to satisfy the stringent operational requirements of advanced flight control systems. However, this has been accomplished largely through brute force hardware redundancy, resulting in significantly increased computational requirements on the flight control computers which perform the failure analysis and reconfiguration management. Modern technology now provides powerful, low-cost microprocessors which are effective in performing failure isolation and configuration management at the local actuator level. One such concept, called an Intelligent Redundant Actuation System (IRAS), significantly reduces the flight control computer requirements and performs the local tasks more comprehensively than previously feasible. The requirements and preliminary design of an experimental laboratory system capable of demonstrating the concept and sufficiently flexible to explore a variety of configurations are discussed.

The Tapered Hybrid Undulator (THUNDER) of the visible free-electron laser oscillator experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, K.E.; Quimby, D.C.; Slater, J.M.

A 5 m tapered hybrid undulator (THUNDER) has been designed and built as part of the Boeing Aerospace Company and Spectra Technology, Inc. visible free-electron laser (FEL) oscillator experiment. The performance goals required of an undulator for a visible oscillator with large extraction are ambitious. They require the establishment of stringent magnetic field quality tolerances which impact design and fabrication techniques. The performance goals of THUNDER are presented. The tolerances resulting from the FEL interaction are contrasted and compared to those of a synchrotron radiation source. The design, fabrication, and field measurements are discussed. The performance of THUNDER serves asmore » a benchmark for future wiggler/undulator design for advanced FEL's and synchrotron radiation sources.« less

Performance intensification of Prague wastewater treatment plant.

PubMed

Novák, L; Havrlíková, D

2004-01-01

Prague wastewater treatment plant was intensified during 1994--1997 by construction of new regeneration tank and four new secondary settling tanks. Nevertheless, more stringent effluent limits and operational problems gave rise to necessity for further intensification and optimisation of plant performance. This paper describes principal operational problems of the plant and shows solutions and achieved results that have lead to plant performance stabilisation. The following items are discussed: low nitrification capacity, nitrification bioaugmentation, activated sludge bulking, insufficient sludge disposal capacity, chemical precipitation of raw wastewater, simultaneous precipitation, sludge chlorination, installation of denitrification zones, sludge rising in secondary settling tanks due to denitrification, dosage of cationic polymeric organic flocculant to secondary settling tanks, thermophilic operation of digestors, surplus activated sludge pre-thickening, mathematical modelling.

Atomic force microscopy characterization of Zerodur mirror substrates for the extreme ultraviolet telescopes aboard NASA's Solar Dynamics Observatory.

PubMed

Soufli, Regina; Baker, Sherry L; Windt, David L; Gullikson, Eric M; Robinson, Jeff C; Podgorski, William A; Golub, Leon

2007-06-01

The high-spatial frequency roughness of a mirror operating at extreme ultraviolet (EUV) wavelengths is crucial for the reflective performance and is subject to very stringent specifications. To understand and predict mirror performance, precision metrology is required for measuring the surface roughness. Zerodur mirror substrates made by two different polishing vendors for a suite of EUV telescopes for solar physics were characterized by atomic force microscopy (AFM). The AFM measurements revealed features in the topography of each substrate that are associated with specific polishing techniques. Theoretical predictions of the mirror performance based on the AFM-measured high-spatial-frequency roughness are in good agreement with EUV reflectance measurements of the mirrors after multilayer coating.

Could martial arts fall training be safe for persons with osteoporosis?: a feasibility study

PubMed Central

2010-01-01

Background Osteoporosis is a well-established risk factor for fall-related hip fractures. Training fall arrest strategies, such as martial arts (MA) fall techniques, might be useful to prevent hip fractures in persons with osteoporosis, provided that the training itself is safe. This study was conducted to determine whether MA fall training would be safe for persons with osteoporosis extrapolated from the data of young adults and using stringent safety criteria. Methods Young adults performed sideways and forward MA falls from a kneeling position on both a judo mat and a mattress as well as from a standing position on a mattress. Hip impact forces and kinematic data were collected. For each condition, the highest hip impact force was compared with two safety criteria based on the femoral fracture load and the use of a hip protector. Results The highest hip impact force during the various fall conditions ranged between 1426 N and 3132 N. Sideways falls from a kneeling and standing position met the safety criteria if performed on the mattress (max 1426 N and 2012 N, respectively) but not if the falls from a kneeling position were performed on the judo mat (max 2219 N). Forward falls only met the safety criteria if performed from a kneeling position on the mattress (max 2006 N). Hence, forward falls from kneeling position on a judo mat (max 2474 N) and forward falls from standing position on the mattress (max 3132 N) did not meet both safety criteria. Conclusions Based on the data of young adults and safety criteria, the MA fall training was expected to be safe for persons with osteoporosis if appropriate safety measures are taken: during the training persons with osteoporosis should wear hip protectors that could attenuate the maximum hip impact force by at least 65%, perform the fall exercises on a thick mattress, and avoid forward fall exercises from a standing position. Hence, a modified MA fall training might be useful to reduce hip fracture risk in persons with osteoporosis. PMID:20412560

The effect of fuel/air mixer design parameters on the continuous and discrete phase structure in the reaction-stabilizing region

NASA Astrophysics Data System (ADS)

Ateshkadi, Arash

The demands on current and future aero gas turbine combustors are demanding a greater insight into the role of the injector/dome design on combustion performance. The structure of the two-phase flow and combustion performance associated with practical injector/dome hardware is thoroughly investigated. A spray injector with two radial inflow swirlers was custom-designed to maintain tight tolerances and strict assembly protocol to isolate the sensitivity of performance to hardware design. The custom set is a unique modular design that (1) accommodates parametric variation in geometry, (2) retains symmetry, and (3) maintains effective area. Swirl sense and presence of a venturi were found to be the most influential on fuel distribution and Lean Blowout. The venturi acts as a fuel-prefilming surface and constrains the highest fuel mass concentration to an annular ring near the centerline. Co-swirl enhances the radial dispersion of the continuous phase and counter-swirl increases the level of mixing that occurs in the downstream region of the mixer. The smallest drop size distributions were found to occur with the counter-swirl configuration with venturi. In the case of counter-swirl without venturi the high concentration of fluid mass is found in the center region of the flow. The Lean Blowout (LBO) equivalence ratio was lower for counter-swirl due to the coupling of the centerline recirculation zone with the location of high fuel concentration emanating from smaller droplets. In the co-swirl configuration a more intense reaction was found near the mixer exit leading to the lowest concentration of NOx, CO and UHC. An LBO model with good agreement to the measured values was developed that related, for the first time, specific hardware parameters and operating condition to stability performance. A semi-analytical model, which agreed best with co-swirl configurations, was modified and used to describe the axial velocity profile downstream of the mixer exit. The development of these two models exemplifies the use of mathematical expressions to guide the design and development procedure for mixer geometry that meet the stringent demands on increasing combustion performance.

Global patterns of protection of elevational gradients in mountain ranges.

PubMed

Elsen, Paul R; Monahan, William B; Merenlender, Adina M

2018-05-21

Protected areas (PAs) that span elevational gradients enhance protection for taxonomic and phylogenetic diversity and facilitate species range shifts under climate change. We quantified the global protection of elevational gradients by analyzing the elevational distributions of 44,155 PAs in 1,010 mountain ranges using the highest resolution digital elevation models available. We show that, on average, mountain ranges in Africa and Asia have the lowest elevational protection, ranges in Europe and South America have intermediate elevational protection, and ranges in North America and Oceania have the highest elevational protection. We use the Convention on Biological Diversity's Aichi Target 11 to assess the proportion of elevational gradients meeting the 17% suggested minimum target and examine how different protection categories contribute to elevational protection. When considering only strict PAs [International Union for Conservation of Nature (IUCN) categories I-IV, n = 24,706], nearly 40% of ranges do not contain any PAs, roughly half fail to meet the 17% target at any elevation, and ∼75% fail to meet the target throughout ≥50% of the elevational gradient. Observed elevational protection is well below optimal, and frequently below a null model of elevational protection. Including less stringent PAs (IUCN categories V-VI and nondesignated PAs, n = 19,449) significantly enhances elevational protection for most continents, but several highly biodiverse ranges require new or expanded PAs to increase elevational protection. Ensuring conservation outcomes for PAs with lower IUCN designations as well as strategically placing PAs to better represent and connect elevational gradients will enhance ecological representation and facilitate species range shifts under climate change. Copyright © 2018 the Author(s). Published by PNAS.

77 FR 1944 - Merchant Marine Personnel Advisory Committee: Intercessional Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-12

... Performance Measures (Assessment Criteria).'' This meeting will be open to the public. DATES: A MERPAC working..., working group meeting is as follows: (1) Review existing performance measures and develop new performance... Committee Working Group Meeting. SUMMARY: The Merchant Marine Personnel Advisory Committee (MERPAC) will...

Is ionizing radiation regulated more stringently than chemical carcinogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Travis, C.C.; Pack, S.R.; Hattemer-Frey, H.A.

1989-04-01

It is widely believed that United States government agencies regulate exposure to ionizing radiation more stringently than exposure to chemical carcinogens. It is difficult to verify this perception, however, because chemical carcinogens and ionizing radiation are regulated using vastly different strategies. Chemical carcinogens are generally regulated individually. Regulators consider the risk of exposure to one chemical rather than the cumulative radiation exposure from all sources. Moreover, standards for chemical carcinogens are generally set in terms of quantities released or resultant environmental concentrations, while standards for ionizing radiation are set in terms of dose to the human body. Since chemicals andmore » ionizing radiation cannot be compared on the basis of equal dose to the exposed individual, standards regulating chemicals and ionizing radiation cannot be compared directly. It is feasible, however, to compare the two sets of standards on the basis of equal risk to the exposed individual, assuming that standards for chemicals and ionizing radiation are equivalent if estimated risk levels are equitable. This paper compares risk levels associated with current standards for ionizing radiation and chemical carcinogens. The authors do not attempt to determine whether either type of risk is regulated too stringently or not stringently enough but endeavor only to ascertain if ionizing radiation is actually regulated more strictly than chemical carcinogens.« less

[Biosimilars--opportunity or threat?].

PubMed

Swierkot, Jerzy

2013-01-01

Strong interest in biosimilars dates back several years. In the coming years the patent protection ends for subsequent biological drugs, including monoclonal antibodies. This paper organizes the most important facts related to the issue of biosimilars. A biosimilar is a biotherapeutic product which is similar in terms of quality, efficacy and safety to an already licensed reference biotherapeutic product'. It should be noted that biosimilars approved underthe current regulations of the European Medicines Agency (EMA) meet the stringent standards of safety, efficacy and immunogenicity. It is also important to realize that the biosimilar has the right to that name, if it is registered by regulatory authorities like EMA or FDA. One should not confuse biosimilar drugs with those which counterfeit or imitate. Clinical trials on the convertibility of innovative and biosimilar drugs are ongoing. Nevertheless,there is no regulatory framework and clear guidelines of conduct in this regard. In the near future, thanks to the registration of the first biosimilar monoclonal antibodies in rheumatology and gastroenterology the availability of biological treatment for patients should increase.

Mission in the works promises precise global topographic data

USGS Publications Warehouse

Farr, T.; Evans, D.; Zebker, H.; Harding, D.; Bufton, J.; Dixon, T.; Vetrella, S.; Gesch, D.B.

1995-01-01

Significant deficiencies in the quality of today's topographic data severely limit scientific applications. Very few available data sets meet the stringent requirements of 10–30 m for global digital topography and 5 m or better vertical accuracy, and existing satellite systems are unlikely to fulfill these requirements. The Joint Topographic Science Working Group, appointed by NASA and the Italian Space Agency, concluded that radar interferometry coupled with a laser altimeter would be the most promising approach for improving data quality. By providing its own illumination at a wavelength Ion g enough to (e.g., λ = 25 cm) to penetrate clouds and rain, the interferometer would provide a global, uniform high-quality topographic data set. One mission under study, TOPSAT, is well positioned to fill this niche and promises to pave the way toward a more standardized and precise topographic database. TOPSAT would be an international mission, designed to make use of recent technology advances in such programs as NASA's New Millennium. It could be ready to launch by the end of this decade.

SWIFT BAT Loop Heat Pipe Thermal System Characteristics and Ground/Flight Operation Procedure

NASA Technical Reports Server (NTRS)

Choi, Michael K.

2003-01-01

The SWIFT Burst Alert Telescope (BAT) Detector Array has a total power dissipation of 208 W. To meet the stringent temperature gradient and thermal stability requirements in the normal operational mode, and heater power budget in both the normal operational and safehold modes, the Detector Array is thermally well coupled to eight constant conductance heat pipes (CCHPs) embedded in the Detector Array Plate (DAP), and two loop heat pipes (LHPs) transport heat fiom the CCHPs to a radiator. The CCHPs have ammonia as the working fluid and the LHPs have propylene as the working fluid. Precision heater controllers, which have adjustable set points in flight, are used to control the LHP compensation chamber and Detector Array XA1 ASIC temperatures. The radiator has the AZ-Tek AZW-LA-II low-alpha white paint as the thermal coating and is located on the anti-sun side of the spacecraft. This paper presents the characteristics, ground operation and flight operation procedures of the LHP thermal system.

The Future of Low-Carbon Transportation Fuels

NASA Astrophysics Data System (ADS)

Yang, Christopher; Yeh, Sonia

2011-11-01

Petroleum fuel uses make up essentially all of transportation fuel usage today and will continue to dominate transportation fuel usage well into future without any major policy changes. This chapter focuses on low-carbon transportation fuels, specifically, biofuels, electricity and hydrogen, that are emerging options to displace petroleum based fuels. The transition to cleaner, lower carbon fuel sources will need significant technology advancement, and sustained coordination efforts among the vehicle and fuel industry and policymakers/regulators over long period of time in order to overcome market barriers, consumer acceptance, and externalities of imported oil. We discuss the unique infrastructure challenges, and compare resource, technology, economics and transitional issues for each of these fuels. While each fuel type has important technical and implementation challenges to overcome (including vehicle technologies) in order to contribute a large fraction of our total fuel demand, it is important to note that a portfolio approach will give us the best chance of meeting stringent environmental and energy security goals for a sustainable transportation future.

A resolution expressing the sense of the Senate that, at the 21st Regular Meeting of the International Commission on the Conservation of Atlantic Tunas, the United States should seek to ensure management of the eastern Atlantic and Mediterranean bluefin tuna fishery adheres to the scientific advice provided by the Standing Committee on Research and Statistics and has a high probability of achieving the established rebuilding target, pursue strengthened protections for spawning bluefin populations in the Mediterranean Sea to facilitate the recovery of the Atlantic bluefin tuna, pursue imposition of more stringent measures to ensure compliance by all Members with the International Commission for the Conservation of Atlantic Tunas' conservation and management recommendations for Atlantic bluefin tuna and other species, and ensure that United States' quotas of tuna and swordfish are not reallocated to other nations, and for other purposes.

THOMAS, 111th Congress

Sen. Snowe, Olympia J. [R-ME

2009-11-09

Senate - 11/09/2009 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

The advanced LIGO input optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, Chris L., E-mail: cmueller@phys.ufl.edu; Arain, Muzammil A.; Ciani, Giacomo

The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions requiredmore » every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Toshiba Display Services, a television picture-tube manufacturer in Horseheads, NY, recently was able to meet stringent state regulations to reduce emissions from two of its film applications lines by installing a regenerative catalytic oxidation system. Toshiba officials initially evaluated several technologies to control volatile organic compounds. After deciding that oxidation was the best technology for its facility, the company invited a number of suppliers to submit proposals. Because all of the oxidation technologies considered by Toshiba had the capability to achieve the destruction and removal efficiency requirement, the company combined the second and third decision elements and conducted an in-depthmore » comparison of the initial capital and ongoing operating costs for each proposal. Officials narrowed the field to two systems--the lowest-cost regenerative thermal oxidation system on the market and a regenerative catalytic oxidation system. The company selected St. Louis, Mo.-based Monsanto Enviro-Chem Systems Inc., to install its DynaCycle{reg_sign} regenerative catalytic oxidation system, marking the first Dyna-Cycle installation in a US television picture-tube facility.« less

Sequential Anaerobic/Aerobic Digestion for Enhanced Carbon/Nitrogen Removal and Cake Odor Reduction.

PubMed

Ahmad, Muneer; Denee, Marco Abel; Jiang, Hao; Eskicioglu, Cigdem; Kadota, Paul; Gregonia, Theresa

2016-12-01

  Anaerobic digestion (AD) has been proven to be an effective process for the treatment of wastewater sludge. However, it produces high levels of ammonia in the digester effluent, which may jeopardize meeting stringent nutrient discharge limits. In this study, the effect of a sequential anaerobic/aerobic (AN/AERO) digestion and a single-stage conventional AN digestion (as control) was investigated on mixed (primary + secondary) sludge generated by the Annacis Island wastewater treatment plant (WWTP) (BC, Canada). An overall sludge retention time (SRT) of 22.5 days under three different scenarios was chosen based on the current operational SRT of the digesters at the Annacis Island WWTP. The steady state results have shown that sequential AN/AERO digestion configurations achieved up to 11% higher volatile solids (VS) removal and 72% lower ammonia generation over single-stage conventional AN digestion. Furthermore, sequential AN/AERO system also showed enhanced dewaterability, improved fecal coliform destruction and reduced digested cake odors over control digesters.

Impacts of using rainwater tanks on stormwater harvesting and runoff quality.

PubMed

Khastagir, A; Jayasuriya, L N N

2010-01-01

The popularity of rainwater use in Australia depends completely on the individual householder's preference. The quality of reticulated water supplies in major cities of Australia is far superior to water stored in rainwater tanks. However, due to persistent drought and the implementation of stringent water restrictions, cities such as Melbourne have encouraged the use of rainwater harvesting within the property. The benefits of trapping stormwater within a property and using it effectively also reduce polluted runoff excess reaching receiving water. The study reported herein focuses on the effectiveness of rainwater tanks as a potential water sensitive urban design element used to manage stormwater using the MUSIC model. The study shows that the installation of a 3 kL tank reduces hydraulic loading by 75%, Total Suspended Solids by 97%, Total Phosphorous by 90% and Total Nitrogen by 81% if the rainwater stored in the tank is used to meet the indoor demand (toilet flushing and laundry use) as well as the outdoor demand (garden watering).

Bonded Lubricants

NASA Technical Reports Server (NTRS)

1977-01-01

Another spinoff to the food processing industry involves a dry lubricant developed by General Magnaplate Corp. of Linden, N.J. Used in such spacecraft as Apollo, Skylab and Viking, the lubricant is a coating bonded to metal surfaces providing permanent lubrication and corrosion resistance. The coating lengthens equipment life and permits machinery to be operated at greater speed, thus increasing productivity and reducing costs. Bonded lubricants are used in scores of commercia1 applications. They have proved particularly valuable to food processing firms because, while increasing production efficiency, they also help meet the stringent USDA sanitation codes for food-handling equipment. For example, a cookie manufacturer plagued production interruptions because sticky batter was clogging the cookie molds had the brass molds coated to solve the problem. Similarly, a pasta producer faced USDA action on a sanitation violation because dough was clinging to an automatic ravioli-forming machine; use of the anti-stick coating on the steel forming plates solved the dual problem of sanitation deficiency and production line downtime.

Open-systems architecture of a standardized command interface chip-set for switching and control of a spacecraft power bus

NASA Technical Reports Server (NTRS)

Ruiz, Ian B.; Burke, Gary R.; Lung, Gerald; Whitaker, William D.; Nowicki, Robert M.

2004-01-01

The Jet Propulsion Laboratory (JPL) has developed a command interface chip-set that primarily consists of two mixed-signal ASICs'; the Command Interface ASIC (CIA) and Analog Interface ASIC (AIA). The Open-systems architecture employed during the design of this chip-set enables its use as both an intelligent gateway between the system's flight computer and the control, actuation, and activation of the spacecraft's loads, valves, and pyrotechnics respectfully as well as the regulator of the spacecraft power bus. Furthermore, the architecture is highly adaptable and employed fault-tolerant design methods enabling a host of other mission uses including reliable remote data collection. The objective of this design is to both provide a needed flight component that meets the stringent environmental requirements of current deep space missions and to add a new element to a growing library that can be used as a standard building block for future missions to the outer planets.

Hydrogeology and ground-water quality of the Bay Mills Indian Community Study Area, near Brimley, Michigan

USGS Publications Warehouse

,

1996-01-01

Bay Mills Indian Community (BMIC) near Brimley, Mich. (fig. 1), with a population of about 1,000, needs hydrogeologic and ground-water-quality information to help assure a reliable ground-water supply for future economic development. Currently (1995), three wells supply water to a housing development adjacent to Mission Hill, but the remainder of BMIC is dependent on private low-capacity wells. Currently (1995), motel and gaming facilities are being constructed at the former Fisherman's Wharf site. These facilities will require large-capacity wells for public supply and fire protection. In addition, a proposed fish hatchery would require a water supply that would meet stringent water-quality requirements and be capable of producing about 500 to 600 gallons per minute (gal/min). This report summarizes hydrogeologic and ground-water-quality information needed to effectively plan for water-supply development at BMIC and is the result of a cooperative effort between BMIC and the U.S. Geological Survey (USGS).

NASA's Space Launch System: An Evolving Capability for Exploration

NASA Technical Reports Server (NTRS)

Creech, Stephen D.; Robinson, Kimberly F.

2016-01-01

Designed to meet the stringent requirements of human exploration missions into deep space and to Mars, NASA's Space Launch System (SLS) vehicle represents a unique new launch capability opening new opportunities for mission design. NASA is working to identify new ways to use SLS to enable new missions or mission profiles. In its initial Block 1 configuration, capable of launching 70 metric tons (t) to low Earth orbit (LEO), SLS is capable of not only propelling the Orion crew vehicle into cislunar space, but also delivering small satellites to deep space destinations. The evolved configurations of SLS, including both the 105 t Block 1B and the 130 t Block 2, offer opportunities for launching co-manifested payloads and a new class of secondary payloads with the Orion crew vehicle, and also offer the capability to carry 8.4- or 10-m payload fairings, larger than any contemporary launch vehicle, delivering unmatched mass-lift capability, payload volume, and C3.

Navigation of the space VLBI mission-HALCA

NASA Technical Reports Server (NTRS)

You, Tung Han; Ellis, Jordan; Mottinger, Neil

1998-01-01

In February 1997, the Japanese Space Agency ISAS launched the first space VLBI satellite, HALCA, with an 8 meter diameter wire mesh antenna and radio astronomy receivers capable of observing at 1.6, 4.8, and 22 Ghz. In a 560 by 21000 km orbit with a 6 hour period and 31 degree inclination, it observes celestial radio sources in conjunction with a world wide network of ground radio telescopes as part of an international collaborative effort which includes facilities in Japan, the U.S., Canada, Australia, and Europe. JPL is providing tracking and navigation support using a dedicated subnet of 11 meter antennas as well as co-observations using the DSN 70 meter antennas. This paper describes the spacecraft dynamics model and orbit determination strategies developed to meet the stringent trajectory accuracy requirements for generating predictions for the transfer of a stable uplink frequency to the spacecraft and for determining reconstructed orbits for delivery to the NRAO VLBI correlator and the international VLBI science community.

Synthesis and analysis of jet fuel from shale oil and coal syncrudes

NASA Technical Reports Server (NTRS)

Gallagher, J. P.; Collins, T. A.; Nelson, T. J.; Pedersen, M. J.; Robison, M. G.; Wisinski, L. J.

1976-01-01

Thirty-two jet fuel samples of varying properties were produced from shale oil and coal syncrudes, and analyzed to assess their suitability for use. TOSCO II shale oil and H-COAL and COED syncrudes were used as starting materials. The processes used were among those commonly in use in petroleum processing-distillation, hydrogenation and catalytic hydrocracking. The processing conditions required to meet two levels of specifications regarding aromatic, hydrogen, sulfur and nitrogen contents at two yield levels were determined and found to be more demanding than normally required in petroleum processing. Analysis of the samples produced indicated that if the more stringent specifications of 13.5% hydrogen (min.) and 0.02% nitrogen (max.) were met, products similar in properties to conventional jet fuels were obtained. In general, shale oil was easier to process (catalyst deactivation was seen when processing coal syncrudes), consumed less hydrogen and yielded superior products. Based on these considerations, shale oil appears to be preferred to coal as a petroleum substitute for jet fuel production.

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R F; Bailey, J E; Cuneo, M E

We report the development of techniques to diagnose plasmas produced by X-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW X-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated 3-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments in which 1 cm, 180 eV tungsten pinches photoionized foils composed of 200{angstrom} Fe and 300{angstrom} NaF co-mixed and sandwiched between 1000{angstrom} layers of Lexan (CHO), and discuss the application of this work to benchmarking astrophysical models.« less

Plasma diagnostics for x-ray driven foils at Z

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heeter, R. F.; Bailey, J. E.; Cuneo, M. E.

We report the development of techniques to diagnose plasmas produced by x-ray photoionization of thin foils placed near the Z-pinch on the Sandia Z Machine. The development of 100+ TW x-ray sources enables access to novel plasma regimes, such as the photoionization equilibrium. To diagnose these plasmas one must simultaneously characterize both the foil and the driving pinch. The desired photoionized plasma equilibrium is only reached transiently for a 2-ns window, placing stringent requirements on diagnostic synchronization. We have adapted existing Sandia diagnostics and fielded an additional gated three-crystal Johann spectrometer with dual lines of sight to meet these requirements.more » We present sample data from experiments using 1-cm, 180-eV tungsten pinches to photoionize foils made of 200 Aa Fe and 300 Aa NaF co-mixed and sandwiched between 1000 Aa layers of Lexan (C16H14O3), and discuss the application of this work to benchmarking astrophysical models.« less

A novel approach to enhance biological nutrient removal using a culture supernatant from Micrococcus luteus containing resuscitation-promoting factor (Rpf) in SBR process.

PubMed

Liu, Yindong; Su, Xiaomei; Lu, Lian; Ding, Linxian; Shen, Chaofeng

2016-03-01

A culture supernatant from Micrococcus luteus containing resuscitation-promoting factor (SRpf) was used to enhance the biological nutrient removal of potentially functional bacteria. The obtained results suggest that SRpf accelerated the start-up process and significantly enhanced the biological nutrient removal in sequencing batch reactor (SBR). PO4 (3-)-P removal efficiency increased by over 12 % and total nitrogen removal efficiency increased by over 8 % in treatment reactor acclimated by SRpf compared with those without SRpf addition. The Illumina high-throughput sequencing analysis showed that SRpf played an essential role in shifts in the composition and diversity of bacterial community. The phyla of Proteobacteria and Actinobacteria, which were closely related to biological nutrient removal, were greatly abundant after SRpf addition. This study demonstrates that SRpf acclimation or addition might hold great potential as an efficient and cost-effective alternative for wastewater treatment plants (WWTPs) to meet more stringent operation conditions and legislations.

Implementation of biological variation-based analytical performance specifications in the laboratory: Stringent evaluation of Improvacutor blood collection tubes.

PubMed

Chung, Hee-Jung; Song, Yoon Kyung; Hong, Sung Kuk; Hwang, Sang-Hyun; Seo, Hee Seung; Whang, Dong Hee; Nam, Myung-Hyun; Lee, Do Hoon

2017-01-01

Recently, because the quality of laboratory analyses has increased along with the need for quality improvement, several external quality control bodies have adapted performance specifications using the Desirable Biological Variation Database, termed "Ricos goals"; these criteria are more stringent than those presented in CLIA 88. In this study, we aimed to validate newly introduced serum separator tubes, Improvacutor, for routine clinical chemistry testing in accordance with Ricos goals and CLIA 88. Blood samples were collected from 100 volunteers into three types of serum vacuum tubes: Greiner Vacuette, Becton Dickinson (BD) Vacutainer, and Improve Improvacutor. The samples were subjected to 16 routine chemistry tests using a TBA-200fr NEO chemistry autoanalyzer. In the comparison analysis, all 16 test results were acceptable according to CLIA 88. However, in the comparison of Improve and BD tubes, creatinine showed 4.31% (+0.08 μmol/L) bias. This slightly exceeded the Desirable Specification for Inaccuracy Ricos limit of ±3.96%, but still satisfied the CLIS88 limit of ±26.52 μmol/L. The remaining 15 analytes performed acceptably according to the Desirable Specifications of Ricos. The correlation coefficient of 12 analytes was greater than 0.95 in Passing-Bablok regression analysis among the three tubes, but was lower for four analytes: calcium, sodium, potassium, and chloride. In the stability assay, only potassium tested in the Greiner tube revealed a larger positive bias (2.18%) than the Ricos Desirable Specification for Inaccuracy based on biologic variation (1.8%). The BD tube also showed a positive bias of 1.74%, whereas the new Improve tube showed the smallest positive bias of 1.17% in potassium level after 72 h storage. Thus, the results of this study demonstrate that recently introduced analytical performance specifications based on components of biological variation (Rico's goal) could be extended to criterion for performance evaluation and applied.

Evolutionary stability concepts in a stochastic environment

NASA Astrophysics Data System (ADS)

Zheng, Xiu-Deng; Li, Cong; Lessard, Sabin; Tao, Yi

2017-09-01

Over the past 30 years, evolutionary game theory and the concept of an evolutionarily stable strategy have been not only extensively developed and successfully applied to explain the evolution of animal behaviors, but also widely used in economics and social sciences. Nonetheless, the stochastic dynamical properties of evolutionary games in randomly fluctuating environments are still unclear. In this study, we investigate conditions for stochastic local stability of fixation states and constant interior equilibria in a two-phenotype model with random payoffs following pairwise interactions. Based on this model, we develop the concepts of stochastic evolutionary stability (SES) and stochastic convergence stability (SCS). We show that the condition for a pure strategy to be SES and SCS is more stringent than in a constant environment, while the condition for a constant mixed strategy to be SES is less stringent than the condition to be SCS, which is less stringent than the condition in a constant environment.

Evaluation of Immunoassays and General Biological Indicator Tests for Field Screening of Bacillus anthracis and Ricin

PubMed Central

Bartholomew, Rachel A.; Ozanich, Richard M.; Arce, Jennifer S.; Engelmann, Heather E.; Heredia-Langner, Alejandro; Hofstad, Beth A.; Hutchison, Janine R.; Jarman, Kristin; Melville, Angela M.; Victry, Kristin D.

2017-01-01

There is little published data on the performance of biological indicator tests and immunoassays that could be used by first responders to determine if a suspicious powder contains a potential biothreat agent. We evaluated a range of biological indicator tests, including 3 protein tests, 2 ATP tests, 1 DNA test, and 1 FTIR spectroscopy instrument for their ability to screen suspicious powders for Bacillus anthracis (B. anthracis) spores and ricin. We also evaluated 12 immunoassays (mostly lateral flow immunoassays) for their ability to screen for B. anthracis and ricin. We used a cost-effective, statistically based test plan that allows instruments to be evaluated at performance levels ranging from 0.85 to 0.95 lower confidence bound of the probability of detection at confidence levels of 80% to 95%. We also assessed interference with 22 common suspicious powders encountered in the field. The detection reproducibility for the biological indicators was evaluated at 108 B. anthracis spores and 62.5 μg ricin, and the immunoassay detection reproducibility was evaluated at 107 spores/mL (B. anthracis) and 0.1 μg/mL (ricin). Seven out of 12 immunoassays met our most stringent criteria for B. anthracis detection, while 9 out of 12 met our most stringent test criteria for ricin detection. Most of the immunoassays also detected ricin in 3 different crude castor seed preparations. Our testing results varied across products and sample preparations, indicating the importance of reviewing performance data for specific instruments and sample types of interest for the application in order to make informed decisions regarding the selection of biodetection equipment for field use. PMID:28192054

Evaluation of Immunoassays and General Biological Indicator Tests for Field Screening of Bacillus anthracis and Ricin.

PubMed

Bartholomew, Rachel A; Ozanich, Richard M; Arce, Jennifer S; Engelmann, Heather E; Heredia-Langner, Alejandro; Hofstad, Beth A; Hutchison, Janine R; Jarman, Kristin; Melville, Angela M; Victry, Kristin D; Bruckner-Lea, Cynthia J

There is little published data on the performance of biological indicator tests and immunoassays that could be used by first responders to determine if a suspicious powder contains a potential biothreat agent. We evaluated a range of biological indicator tests, including 3 protein tests, 2 ATP tests, 1 DNA test, and 1 FTIR spectroscopy instrument for their ability to screen suspicious powders for Bacillus anthracis (B. anthracis) spores and ricin. We also evaluated 12 immunoassays (mostly lateral flow immunoassays) for their ability to screen for B. anthracis and ricin. We used a cost-effective, statistically based test plan that allows instruments to be evaluated at performance levels ranging from 0.85 to 0.95 lower confidence bound of the probability of detection at confidence levels of 80% to 95%. We also assessed interference with 22 common suspicious powders encountered in the field. The detection reproducibility for the biological indicators was evaluated at 10 8 B. anthracis spores and 62.5 μg ricin, and the immunoassay detection reproducibility was evaluated at 10 7 spores/mL (B. anthracis) and 0.1 μg/mL (ricin). Seven out of 12 immunoassays met our most stringent criteria for B. anthracis detection, while 9 out of 12 met our most stringent test criteria for ricin detection. Most of the immunoassays also detected ricin in 3 different crude castor seed preparations. Our testing results varied across products and sample preparations, indicating the importance of reviewing performance data for specific instruments and sample types of interest for the application in order to make informed decisions regarding the selection of biodetection equipment for field use.

ASTM and ASME-BPE Standards--Complying with the Needs of the Pharmaceutical Industry.

PubMed

Huitt, William M

2011-01-01

Designing and building a pharmaceutical facility requires the owner, engineer of record, and constructor to be knowledgeable with regard to the industry codes and standards that apply to this effort. Up until 1997 there were no industry standards directed at the needs and requirements of the pharmaceutical industry. Prior to that time it was a patchwork effort at resourcing and adopting nonpharmaceutical-related codes and standards and then modifying them in order to meet the more stringent requirements of the Food and Drug Administration (FDA). In 1997 the American Society of Mechanical Engineers (ASME) published the first Bioprocessing Equipment (BPE) Standard. Through harmonization efforts this relatively new standard has brought together, scrutinized, and refined industry accepted methodologies together with FDA compliance requirements, and has established an American National Standard that provides a comprehensive set of standards that are integral to the pharmaceutical industry. This article describes various American National Standards, including those developed and published by the American Society for Testing and Materials (ASTM), and how they apply to the pharmaceutical industry. It goes on to discuss the harmonization effort that takes place between the various standards developers in an attempt to prevent conflicts and omissions between the many standards. Also included are examples of tables and figures taken from the ASME-BPE Standard. These examples provide the reader with insight to the relevant content of the ASME-BPE Standard. Designing and building a pharmaceutical facility requires the owner, engineer of record, and constructor to be knowledgeable with regard to the industry codes and standards that apply to this effort. Up until 1997 there were no industry standards directed at the needs and requirements of the pharmaceutical industry. Prior to that time it was a patchwork effort at resourcing and adopting nonpharmaceutical-related codes and standards and then modifying them in order to meet the more stringent requirements of the Food and Drug Administration (FDA). In 1997 the American Society of Mechanical Engineers (ASME) published the first Bioprocessing Equipment (BPE) Standard. In its initial development and ongoing maintenance it works with other American National Standards developers to harmonize the many standards associated with the design, engineering, and construction of bioprocessing facilities. This harmonization effort has established a comprehensive set of standards for the betterment of the pharmaceutical industry at large. This effort is, and will remain, very important as technology, along with new and improved product and processes, evolve into the future.

Proportion of US adults potentially affected by the 2014 hypertension guideline.

PubMed

Navar-Boggan, Ann Marie; Pencina, Michael J; Williams, Ken; Sniderman, Allan D; Peterson, Eric D

2014-04-09

The new 2014 blood pressure (BP) guideline released by the panel members appointed to the Eighth Joint National Committee (JNC 8; 2014 BP guideline) proposed less restrictive BP targets for adults aged 60 years or older and for those with diabetes and chronic kidney disease. To estimate the proportion of US adults potentially affected by recent changes in recommendations for management of hypertension. Cross-sectional, nationally representative survey. Using data from the National Health and Nutrition Examination Survey between 2005 and 2010 (n = 16,372), we evaluated hypertension control and treatment recommendations for US adults. Proportion of adults estimated to meet guideline-based BP targets under the 2014 BP guideline and under the previous seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guideline. The proportion of younger adults (18-59 years) with treatment-eligible hypertension under the JNC 7 guideline was 20.3% (95% CI, 19.1%-21.4%) and decreased to 19.2% (95% CI, 18.1%-20.4%) under the 2014 BP guideline. Larger declines were observed among older adults (≥60 years), decreasing from 68.9% (95% CI, 66.9%-70.8%) under JNC 7 to 61.2% (95% CI, 59.3%-63.0%) under the 2014 BP guideline. The proportion of adults with treatment-eligible hypertension who met BP goals increased slightly for younger adults, from 41.2% (95% CI, 38.1%-44.3%) under JNC 7 to 47.5% (95% CI, 44.4%-50.6%) under the 2014 BP guideline, and more substantially for older adults, from 40.0% (95% CI, 37.8%-42.3%) under JNC 7 to 65.8% (95% CI, 63.7%-67.9%) under the 2014 BP guideline. Overall, 1.6% (95% CI, 1.3%-1.9%) of US adults aged 18-59 years and 27.6% (95% CI, 25.9%-29.3%) of adults aged 60 years or older were receiving BP-lowering medication and meeting more stringent JNC 7 targets. These patients may be eligible for less stringent or no BP therapy with the 2014 BP guideline. Compared with the JNC 7 guideline, the 2014 BP guideline from the panel members appointed to the JNC 8 was associated with a reduction in the proportion of US adults recommended for hypertension treatment and a substantial increase in the proportion of adults considered to have achieved goal BP, primarily in older adults.

The control of satellites with microgravity constraints: The COMET Control System

NASA Astrophysics Data System (ADS)

Grossman, Walter; Freesland, Douglas

1994-05-01

The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.

The control of satellites with microgravity constraints: The COMET Control System

NASA Technical Reports Server (NTRS)

Grossman, Walter; Freesland, Douglas

1994-01-01

The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.

Physical insight into the simultaneous optimization of structure and control

NASA Technical Reports Server (NTRS)

Jacques, Robert N.; Miller, David W.

1993-01-01

Recent trends in spacecraft design which yield larger structures with more stringent performance requirements place many flexible modes of the structure within the bandwidth of active controllers. The resulting complications to the spacecraft design make it highly desirable to understand the impact of structural changes on an optimally controlled structure. This work uses low structural models with optimal H(sub 2) and H(sub infinity) controllers to develop some basic insight into this problem. This insight concentrates on several basic approaches to improving controlled performance and how these approaches interact in determining the optimal designs. A numerical example is presented to demonstrate how this insight can be generalized to more complex problems.

Movement amplitude and tempo change in piano performance

NASA Astrophysics Data System (ADS)

Palmer, Caroline

2004-05-01

Music performance places stringent temporal and cognitive demands on individuals that should yield large speed/accuracy tradeoffs. Skilled piano performance, however, shows consistently high accuracy across a wide variety of rates. Movement amplitude may affect the speed/accuracy tradeoff, so that high accuracy can be obtained even at very fast tempi. The contribution of movement amplitude changes in rate (tempo) is investigated with motion capture. Cameras recorded pianists with passive markers on hands and fingers, who performed on an electronic (MIDI) keyboard. Pianists performed short melodies at faster and faster tempi until they made errors (altering the speed/accuracy function). Variability of finger movements in the three motion planes indicated most change in the plane perpendicular to the keyboard across tempi. Surprisingly, peak amplitudes of motion before striking the keys increased as tempo increased. Increased movement amplitudes at faster rates may reduce or compensate for speed/accuracy tradeoffs. [Work supported by Canada Research Chairs program, HIMH R01 45764.

Strategic parenting, birth order, and school performance.

PubMed

Hotz, V Joseph; Pantano, Juan

2015-10-01

Fueled by new evidence, there has been renewed interest about the effects of birth order on human capital accumulation. The underlying causal mechanisms for such effects remain unsettled. We consider a model in which parents impose more stringent disciplinary environments in response to their earlier-born children's poor performance in school in order to deter such outcomes for their later-born offspring. We provide robust empirical evidence that school performance of children in the National Longitudinal Study Children (NLSY-C) declines with birth order as does the stringency of their parents' disciplinary restrictions. When asked how they will respond if a child brought home bad grades, parents state that they would be less likely to punish their later-born children. Taken together, these patterns are consistent with a reputation model of strategic parenting.

Strategic parenting, birth order, and school performance

PubMed Central

Pantano, Juan

2015-01-01

Fueled by new evidence, there has been renewed interest about the effects of birth order on human capital accumulation. The underlying causal mechanisms for such effects remain unsettled. We consider a model in which parents impose more stringent disciplinary environments in response to their earlier-born children’s poor performance in school in order to deter such outcomes for their later-born offspring. We provide robust empirical evidence that school performance of children in the National Longitudinal Study Children (NLSY-C) declines with birth order as does the stringency of their parents’ disciplinary restrictions. When asked how they will respond if a child brought home bad grades, parents state that they would be less likely to punish their later-born children. Taken together, these patterns are consistent with a reputation model of strategic parenting. PMID:26366045

Atomic force microscopy characterization of Zerodur mirror substrates for the extreme ultraviolet telescopes aboard NASA's Solar Dynamics Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soufli, Regina; Baker, Sherry L.; Windt, David L.

2007-06-01

The high-spatial frequency roughness of a mirror operating at extreme ultraviolet (EUV)wavelengths is crucial for the reflective performance and is subject to very stringent specifications. To understand and predict mirror performance, precision metrology is required for measuring the surface roughness. Zerodur mirror substrates made by two different polishing vendors for a suite of EUV telescopes for solar physics were characterized by atomic force microscopy (AFM). The AFM measurements revealed features in the topography of each substrate that are associated with specific polishing techniques. Theoretical predictions of the mirror performance based on the AFM-measured high-spatial-frequency roughness are in good agreement withmore » EUV reflectance measurements of the mirrors after multilayer coating.« less

An Ada implementation of the network manager for the advanced information processing system

NASA Technical Reports Server (NTRS)

Nagle, Gail A.

1986-01-01

From an implementation standpoint, the Ada language provided many features which facilitated the data and procedure abstraction process. The language supported a design which was dynamically flexible (despite strong typing), modular, and self-documenting. Adequate training of programmers requires access to an efficient compiler which supports full Ada. When the performance issues for real time processing are finally addressed by more stringent requirements for tasking features and the development of efficient run-time environments for embedded systems, the full power of the language will be realized.

Results from the CUORE-0 experiment

DOE PAGES

Canonica, L.; Alduino, C.; Alfonso, K.; ...

2016-06-09

The CUORE-0 experiment searched for neutrinoless double beta decay in 130 Te using an array of 52 tellurium dioxide crystals, operated as bolometers at a temperature of 10 mK. It took data in the Gran Sasso National Laboratory (Italy) since March 2013 to March 2015. We present the results of a search for neutrinoless double beta decay in 9.8 kg-years 130 Te exposure that allowed us to set the most stringent limit to date on this half-life. The performance of the detector in terms of background and energy resolution is also reported.

Design, fabrication, and operation of dished accelerator grids on a 30-cm ion thruster

NASA Technical Reports Server (NTRS)

Rawlin, V. K.; Banks, B. A.; Byers, D. C.

1972-01-01

Several closely-space dished accelerator grid systems were fabricated and tested on a 30-cm diameter mercury bombardment thruster and they appear to be a solution to the stringent requirements imposed by the near-term, high-thrust, low specific impulse electric propulsion missions. The grids were simultaneously hydroformed and then simultaneously stress relieved. The ion extraction capability and discharge chamber performance were studied as the total accelerating voltage, the ratio of net-to-total voltage, grid spacing, and dish direction were varied.

Design, Qualification, and On Orbit Performance of the CALIPSO Aerosol Lidar Transmitter

NASA Technical Reports Server (NTRS)

Hovis, Floyd E.; Witt, Greg; Sullivan, Edward T.; Le, Khoa; Weimer, Carl; Applegate, Jeff; Luck, William S., Jr.; Verhapen, Ron; Cisewski, Michael S.

2007-01-01

The laser transmitter for the CALIPSO aerosol lidar mission has been operating on orbit as planned since June 2006. This document discusses the optical and laser system design and qualification process that led to this success. Space-qualifiable laser design guidelines included the use of mature laser technologies, the use of alignment sensitive resonator designs, the development and practice of stringent contamination control procedures, the operation of all optical components at appropriately derated levels, and the proper budgeting for the space-qualification of the electronics and software.

Control system design for flexible structures using data models

NASA Technical Reports Server (NTRS)

Irwin, R. Dennis; Frazier, W. Garth; Mitchell, Jerrel R.; Medina, Enrique A.; Bukley, Angelia P.

1993-01-01

The dynamics and control of flexible aerospace structures exercises many of the engineering disciplines. In recent years there has been considerable research in the developing and tailoring of control system design techniques for these structures. This problem involves designing a control system for a multi-input, multi-output (MIMO) system that satisfies various performance criteria, such as vibration suppression, disturbance and noise rejection, attitude control and slewing control. Considerable progress has been made and demonstrated in control system design techniques for these structures. The key to designing control systems for these structures that meet stringent performance requirements is an accurate model. It has become apparent that theoretically and finite-element generated models do not provide the needed accuracy; almost all successful demonstrations of control system design techniques have involved using test results for fine-tuning a model or for extracting a model using system ID techniques. This paper describes past and ongoing efforts at Ohio University and NASA MSFC to design controllers using 'data models.' The basic philosophy of this approach is to start with a stabilizing controller and frequency response data that describes the plant; then, iteratively vary the free parameters of the controller so that performance measures become closer to satisfying design specifications. The frequency response data can be either experimentally derived or analytically derived. One 'design-with-data' algorithm presented in this paper is called the Compensator Improvement Program (CIP). The current CIP designs controllers for MIMO systems so that classical gain, phase, and attenuation margins are achieved. The center-piece of the CIP algorithm is the constraint improvement technique which is used to calculate a parameter change vector that guarantees an improvement in all unsatisfied, feasible performance metrics from iteration to iteration. The paper also presents a recently demonstrated CIP-type algorithm, called the Model and Data Oriented Computer-Aided Design System (MADCADS), developed for achieving H(sub infinity) type design specifications using data models. Control system design for the NASA/MSFC Single Structure Control Facility are demonstrated for both CIP and MADCADS. Advantages of design-with-data algorithms over techniques that require analytical plant models are also presented.