Science.gov

Sample records for reference designs study

  1. Mars Design Reference Architecture 5.0 Study: Executive Summary

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.

    2008-01-01

    The NASA Mars Design Reference Architecture 5.0 Study seeks to update its long term goals and objective for human exploration missions; flight and surface systems for human missions and supporting infrastructure; operational concept for human and robotic exploration of Mars; key challenges including risk and cost drivers; and, its development schedule options. It additionally seeks to assess strategic linkages between lunar and Mars strategies and develop and understanding of methods for reducing the cost/risk of human Mars missions through investment in research, technology development, and synergy with other exploration plans. Recommendations are made regarding conjunction class (long-stay) missions which are seen as providing the best balance of cost, risk, and performance. Additionally, this study reviews entry, descent, and landing challenges; in-space transportation systems; launch vehicle and Orion assessments; risk and risk mitigation; key driving requirements and challenges; and, lunar linkages.

  2. Mars Aerocapture Studies for the Design Reference Mission

    NASA Technical Reports Server (NTRS)

    Lyne, James Evans; Wercinski, Paul; Walberg, Gerald; Jits, Roman

    1997-01-01

    The recent discovery of possible fossilized microbes in a Martian meteorite sample and the spectacular success of the Mars Pathfinder mission have substantially increased public interest and support for future robotic and manned exploration of Mars. NASA is currently refining a plan known as the Design Reference Mission (DRM) in which the first human landing would occur in 2014 after a series of cargo launches which would place surface systems and an Earth return vehicle at Mars two years prior to the crew's arrival. At each subsequent launch opportunity (which occur approximately every twenty-six months), an additional Earth return vehicle, surface facility and crew would depart for Mars, with each crew employing the systems launched during the previous opportunity. The mission design calls for a long-duration surface stay, rapid crew transits, in-situ manufacture of the Mars ascent propellant, nuclear thermal propulsion for the trans-Mars injection burn, and the use of aerocapture for both the cargo and crew vehicles at Mars.

  3. Design and Cohort Characteristics of the Social Spectrum Study: A Multicenter Study of the Autism Spectrum among Clinically Referred Children

    ERIC Educational Resources Information Center

    Duvekot, Jorieke; Hoopen, Leontine W.; Slappendel, Geerte; van der Ende, Jan; Verhulst, Frank C.; van der Sijde, Ad; Greaves-Lord, Kirstin

    2017-01-01

    This paper provides an overview of the design and cohort characteristics of the Social Spectrum Study: a clinical cohort study that used a two-phase sampling design to identify children at risk for ASD. After screening 1281 children aged 2.5-10 years who had been consecutively referred to one of six mental health services in the Netherlands,…

  4. ILC cryogenic systems reference design

    SciTech Connect

    Peterson, T.J.; Geynisman, M.; Klebaner, A.; Theilacker, J.; Parma, V.; Tavian, L.; /CERN

    2008-01-01

    A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

  5. The value of well-designed experiments in studying diseases with special reference to amphibians.

    PubMed

    Blaustein, Andrew R; Alford, Ross A; Harris, Reid N

    2009-09-01

    Relatively few studies of amphibian diseases have employed standard ecological experimental designs. We discuss what constitutes a well-designed ecological experiment and encourage their use in disease studies. We illustrate how well-designed experiments can be used to determine the effects of pathogens on amphibians and we illustrate how ancillary information, including that collected using molecular tools, can be used to enhance the value of such experiments.

  6. The Reference Ability Neural Network Study: motivation, design, and initial feasibility analyses.

    PubMed

    Stern, Yaakov; Habeck, Christian; Steffener, Jason; Barulli, Daniel; Gazes, Yunglin; Razlighi, Qolamreza; Shaked, Danielle; Salthouse, Timothy

    2014-12-01

    We introduce and describe the Reference Ability Neural Network Study and provide initial feasibility data. Based on analyses of large test batteries administered to individuals ranging from young to old, four latent variables, or reference abilities (RAs) that capture the majority of the variance in age-related cognitive change have been identified: episodic memory, fluid reasoning, perceptual speed, and vocabulary. We aim to determine whether spatial fMRI networks can be derived that are uniquely associated with the performance of each reference ability. We plan to image 375 healthy adults (50 per decade from age 20 to 50; 75 per decade from age 50 to 80) while performing a set of 12 cognitive tasks. Data on 174 participants are reported here. Three tasks were grouped a priori into each of the four reference ability domains. We first assessed to what extent both cognitive task scores and activation patterns readily show convergent and discriminant validity, i.e. increased similarity between tasks within the same domain and decreased similarity between tasks between domains, respectively. Block-based time-series analysis of each individual task was conducted for each participant via general linear modeling. We partialled activation common to all tasks out of the imaging data. For both test scores and activation topographies, we then calculated correlations for each of 66 possible pairings of tasks, and compared the magnitude of correlation of tasks within reference ability domains to that of tasks between domains. For the behavioral data, globally there were significantly stronger inter-task correlations within than between domains. When examining individual abilities, 3 of the domains also met these criteria but memory reached only borderline significance. Overall there was greater topographic similarity within reference abilities than between them (p<0.0001), but when examined individually, statistical significance was reached only for episodic memory and

  7. The Reference Ability Neural Network Study: Motivation, Design, and Initial Feasibility Analyses

    PubMed Central

    Stern, Yaakov; Habeck, Christian; Steffener, Jason; Barulli, Daniel; Gazes, Yunglin; Razlighi, Qolamreza; Shaked, Danielle; Salthouse, Timothy

    2014-01-01

    We introduce and describe the Reference Ability Neural Network Study and provide initial feasibility data. Based on analyses of large test batteries administered to individuals ranging from young to old, four latent variables, or reference abilities (RAs) that capture the majority of the variance in age-related cognitive change have been identified: episodic memory, fluid reasoning, perceptual speed, and vocabulary. We aim to determine whether spatial fMRI networks can be derived that are uniquely associated with the performance of each reference ability. We plan to image 375 healthy adults (50 per decade from age 20 to 50; 75 per decade from age 50 to 80) while performing a set of 12 cognitive tasks. Data on 174 participants are reported here. Three tasks were grouped a priori into each of the four reference ability domains. We first assessed to what extent both cognitive task scores and activation patterns readily show convergent and discriminant validity, i.e. increased similarity between tasks within the same domain and decreased similarity between tasks between domains, respectively. Block-based time-series analysis of each individual task was conducted for each participant via general linear modeling. We partialled activation common to all tasks out of the imaging data. For both test scores and activation topographies, we then calculated correlations for each of 66 possible pairings of tasks, and compared the magnitude of correlation of tasks within reference ability domains to that of tasks between domains. For the behavioral data, globally there were significantly stronger inter-task correlations within than between domains. When examining individual abilities, 3 of the domains also met these criteria but memory reached only borderline significance. Overall there was greater topographic similarity within reference abilities than between them (p<0.0001), but when examined individually, statistical significance was reached only for episodic memory and

  8. Validation Studies for Numerical Simulations of Flow Phenomena Expected in the Lower Plenum of a Prismatic VHTR Reference Design

    SciTech Connect

    Richard W. Johnson

    2005-09-01

    The final design of the very high temperature reactor (VHTR) of the fourth generation of nuclear power plants (Gen IV) has not yet been established. The VHTR may be either a prismatic (block) or pebble bed type. It may be either gas-cooled or cooled with an as yet unspecified molten salt. However, a conceptual design of a gas-cooled VHTR, based on the General Atomics GT-MHR, does exist and is called the prismatic VHTR reference design, MacDonald et al [2003], General Atomics [1996]. The present validation studies are based on the prismatic VHTR reference design. In the prismatic VHTR reference design, the flow in the lower plenum will be introduced by dozens of turbulent jets issuing into a large crossflow that must negotiate dozens of cylindrical support columns as it flows toward the exit duct of the reactor vessel. The jets will not all be at the same temperature due to the radial variation of power density expected in the core. However, it is important that the coolant be well mixed when it enters the power conversion unit to ensure proper operation and long life of the power conversion machinery. Hence, it is deemed important to be able to accurately model the flow and mixing of the variable temperature coolant in the lower plenum and exit duct. Accurate flow modeling involves determining modeling strategies including the fineness of the grid needed, iterative convergence tolerance, numerical discretization method used, whether the flow is steady or unsteady, and the turbulence model and wall treatment employed. It also involves validation of the computer code and turbulence model against a series of separate and combined flow phenomena and selection of the data used for the validation. The present report describes progress made to date for the task entitled ‘CFD software validation of jets in crossflow’ which was designed to investigate the issues pertaining to the validation process.

  9. Gathering Design References from Nature

    ERIC Educational Resources Information Center

    Debs, Luciana; Kelley, Todd

    2015-01-01

    Teaching design to middle and high school students can be challenging. One of the first procedures in teaching design is to help students gather information that will be useful in the design phase. An early stage of engineering design as described by Lewis (2005), calls for the designer to establish the state of the art of the problem. During this…

  10. A reference Pelton turbine design

    NASA Astrophysics Data System (ADS)

    Solemslie, B. W.; Dahlhaug, O. G.

    2012-09-01

    The designs of hydraulic turbines are usually close kept corporation secrets. Therefore, the possibility of innovation and co-operation between different academic institutions regarding a specific turbine geometry is difficult. A Ph.D.-project at the Waterpower Laboratory, NTNU, aim to design several model Pelton turbines where all measurements, simulations, the design strategy, design software in addition to the physical model will be available to the public. In the following paper a short description of the methods and the test rig that are to be utilized in the project are described. The design will be based on empirical data and NURBS will be used as the descriptive method for the turbine geometry. In addition CFX and SPH simulations will be included in the design process. Each turbine designed and produced in connection to this project will be based on the experience and knowledge gained from the previous designs. The first design will be based on the philosophy to keep a near constant relative velocity through the bucket.

  11. Benefits of statistical molecular design, covariance analysis, and reference models in QSAR: a case study on acetylcholinesterase

    NASA Astrophysics Data System (ADS)

    Andersson, C. David; Hillgren, J. Mikael; Lindgren, Cecilia; Qian, Weixing; Akfur, Christine; Berg, Lotta; Ekström, Fredrik; Linusson, Anna

    2015-03-01

    Scientific disciplines such as medicinal- and environmental chemistry, pharmacology, and toxicology deal with the questions related to the effects small organic compounds exhort on biological targets and the compounds' physicochemical properties responsible for these effects. A common strategy in this endeavor is to establish structure-activity relationships (SARs). The aim of this work was to illustrate benefits of performing a statistical molecular design (SMD) and proper statistical analysis of the molecules' properties before SAR and quantitative structure-activity relationship (QSAR) analysis. Our SMD followed by synthesis yielded a set of inhibitors of the enzyme acetylcholinesterase (AChE) that had very few inherent dependencies between the substructures in the molecules. If such dependencies exist, they cause severe errors in SAR interpretation and predictions by QSAR-models, and leave a set of molecules less suitable for future decision-making. In our study, SAR- and QSAR models could show which molecular sub-structures and physicochemical features that were advantageous for the AChE inhibition. Finally, the QSAR model was used for the prediction of the inhibition of AChE by an external prediction set of molecules. The accuracy of these predictions was asserted by statistical significance tests and by comparisons to simple but relevant reference models.

  12. EBT-P proposed reference design report

    SciTech Connect

    Boch, A.L.

    1980-01-01

    This report describes the proposed reference design for the EBT-P proof-of-principle test device. The device described is a result of broad studies by many participating organizations from industry and from Department of Energy-sponsored fusion research groups, some working together and some in competitive studies, but all with the goal of defining a device at minimum cost and with maximum probability of meeting its goals. This design work is based upon advances in experimental and theoretical understanding of EBT achieved at Oak Ridge National Laboratory. The strategy adopted permits an initial test and validation of the key scaling properties of the ELMO Bumpy Torus concept, with a degree of built-in flexibility to extend the performance parameters toward the condition for containing a fusion reactor plasma. This will lead the way, then, to determination of a later power break-even demonstration and an eventual fusion reactor that can exploit the special high power-density and steady-state properties of the EBT concept.

  13. Crew Transportation System Design Reference Missions

    NASA Technical Reports Server (NTRS)

    Mango, Edward J.

    2015-01-01

    Contains summaries of potential design reference mission goals for systems to transport humans to andfrom low Earth orbit (LEO) for the Commercial Crew Program. The purpose of this document is to describe Design Reference Missions (DRMs) representative of the end-to-end Crew Transportation System (CTS) framework envisioned to successfully execute commercial crew transportation to orbital destinations. The initial CTS architecture will likely be optimized to support NASA crew and NASA-sponsored crew rotation missions to the ISS, but consideration may be given in this design phase to allow for modifications in order to accomplish other commercial missions in the future. With the exception of NASA’s mission to the ISS, the remaining commercial DRMs are notional. Any decision to design or scar the CTS for these additional non-NASA missions is completely up to the Commercial Provider. As NASA’s mission needs evolve over time, this document will be periodically updated to reflect those needs.

  14. MSDS sky reference and preamplifier study

    NASA Technical Reports Server (NTRS)

    Larsen, L.; Stewart, S.; Lambeck, P.

    1974-01-01

    The major goals in re-designing the Multispectral Scanner and Data System (MSDS) sky reference are: (1) to remove the sun-elevation angle and aircraft-attitude angle dependence from the solar-sky illumination measurement, and (2) to obtain data on the optical state of the atmosphere. The present sky reference is dependent on solar elevation and provides essentially no information on important atmospheric parameters. Two sky reference designs were tested. One system is built around a hyperbolic mirror and the reflection approach. A second approach to a sky reference utilizes a fish-eye lens to obtain a 180 deg field of view. A detailed re-design of the present sky reference around the fish-eye approach, even with its limitations, is recommended for the MSDS system. A preamplifier study was undertaken to find ways of improving the noise-equivalent reflectance by reducing the noise level for silicon detector channels on the MSDS.

  15. International linear collider reference design report

    SciTech Connect

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  16. Automotive Stirling reference engine design report

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The reference Stirling engine system is described which provides the best possible fuel economy while meeting or exceeding all other program objectives. The system was designed to meet the requirements of a 1984 Pontiac Phoenix (X-body). This design utilizes all new technology that can reasonably be expected to be developed by 1984 and that is judged to provide significant improvement, relative to development risk and cost. Topics covered include: (1) external heat system; (2) hot engine system; (3) cold engine system; (4) engine drive system; (5) power control system and auxiliaries; (6) engine instalation; (7) optimization and vehicle simulation; (8) engine materials; and (9) production cost analysis.

  17. ILC Reference Design Report: Accelerator Executive Summary

    SciTech Connect

    Phinney, Nan; /SLAC

    2007-12-14

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radiofrequency (SCRF) accelerating cavities. The use of the SCRF technology was recommended by the International Technology Recommendation Panel (ITRP) in August 2004 [1], and shortly thereafter endorsed by the International Committee for Future Accelerators (ICFA). In an unprecedented milestone in high-energy physics, the many institutes around the world involved in linear collider R&D united in a common effort to produce a global design for the ILC. In November 2004, the 1st International Linear Collider Workshop was held at KEK, Tsukuba, Japan. The workshop was attended by some 200 accelerator physicists from around the world, and paved the way for the 2nd ILC Workshop in August 2005, held at Snowmass, Colorado, USA, where the ILC Global Design Effort (GDE) was officially formed. The GDE membership reflects the global nature of the collaboration, with accelerator experts from all three regions (Americas, Asia and Europe). The first major goal of the GDE was to define the basic parameters and layout of the machine--the Baseline Configuration. This was achieved at the first GDE meeting held at INFN, Frascati, Italy in December 2005 with the creation of the Baseline Configuration Document (BCD). During the next 14 months, the BCD was used as the basis for the detailed design work and value estimate (as described in section 1.6) culminating in the completion of the second major milestone, the publication of the draft ILC Reference Design Report (RDR). The technical design and cost estimate for the ILC is based on two decades of world-wide Linear Collider R&D, beginning with the construction and operation of the SLAC Linear Collider (SLC). The SLC is acknowledged as a proof-of-principle machine for the linear collider concept. The ILC SCRF linac technology was pioneered by the TESLA collaboration*, culminating in

  18. Reference repository design concept for bedded salt

    SciTech Connect

    Carpenter, D.W.; Martin, R.W.

    1980-10-08

    A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

  19. Nuclear Thermal Rocket/Vehicle Characteristics And Sensitivity Trades For NASA's Mars Design Reference Architecture (DRA) 5.0 Study

    NASA Technical Reports Server (NTRS)

    Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

    2009-01-01

    This paper summarizes Phase I and II analysis results from NASA's recent Mars DRA 5.0 study which re-examined mission, payload and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal rocket (NTR) propulsion was again identified as the preferred in-space transportation system over chemical/aerobrake because of its higher specific impulse (I(sub sp)) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit (IMLEO) which is important for reducing the number of Ares-V heavy lift launches and overall mission cost. DRA 5.0 features a long surface stay (approximately 500 days) split mission using separate cargo and crewed Mars transfer vehicles (MTVs). All vehicles utilize a common core propulsion stage with three 25 klbf composite fuel NERVA-derived NTR engines (T(sub ex) approximately 2650 - 2700 K, p(sub ch) approximately 1000 psia, epsilon approximately 300:1, I(sub sp) approximately 900 - 910 s, engine thrust-toweight ratio approximately 3.43) to perform all primary mission maneuvers. Two cargo flights, utilizing 1-way minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crewed MTV during the next mission opportunity (approximately 26 months later). The cargo payload elements aerocapture (AC) into Mars orbit and are enclosed within a large triconicshaped aeroshell which functions as payload shroud during launch, then as an aerobrake and thermal protection system during Mars orbit capture and subsequent entry, descent and landing (EDL) on Mars. The all propulsive crewed MTV is a 0-gE vehicle design that utilizes a fast conjunction trajectory that allows approximately 6-7 month 1-way transit times to and from Mars. Four 12.5 kW(sub e) per 125 square meter rectangular photovoltaic arrays provide the crewed MTV with

  20. Moderator design studies for a new neutron reference source based on the D-T fusion reaction

    NASA Astrophysics Data System (ADS)

    Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

    2016-06-01

    The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuteriumtritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2-5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

  1. Moderator design studies for a new neutron reference source based on the D–T fusion reaction

    SciTech Connect

    Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

    2016-06-01

    The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuterium-tritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14.6 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2 to 5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

  2. A Future Large-Aperture UVOIR Space Observatory: Reference Designs

    NASA Technical Reports Server (NTRS)

    Thronson, Harley; Rioux, Norman; Feinberg, Lee; Stahl, H. Philip; Redding, Dave; Jones, Andrew; Sturm, James; Collins, Christine; Liu, Alice

    2015-01-01

    Our joint NASA GSFC/JPL/MSFC/STScI study team has used community-provided science goals to derive mission needs, requirements, and candidate mission architectures for a future large-aperture, non-cryogenic UVOIR space observatory. We describe the feasibility assessment of system thermal and dynamic stability for supporting coronagraphy. The observatory is in a Sun-Earth L2 orbit providing a stable thermal environment and excellent field of regard. Reference designs include a 36-segment 9.2 m aperture telescope that stows within a five meter diameter launch vehicle fairing. Performance needs developed under the study are traceable to a variety of reference designs including options for a monolithic primary mirror.

  3. A future large-aperture UVOIR space observatory: reference designs

    NASA Astrophysics Data System (ADS)

    Rioux, Norman; Thronson, Harley; Feinberg, Lee; Stahl, H. Philip; Redding, Dave; Jones, Andrew; Sturm, James; Collins, Christine; Liu, Alice

    2015-09-01

    Our joint NASA GSFC/JPL/MSFC/STScI study team has used community-provided science goals to derive mission needs, requirements, and candidate mission architectures for a future large-aperture, non-cryogenic UVOIR space observatory. We describe the feasibility assessment of system thermal and dynamic stability for supporting coronagraphy. The observatory is in a Sun-Earth L2 orbit providing a stable thermal environment and excellent field of regard. Reference designs include a 36-segment 9.2 m aperture telescope that stows within a five meter diameter launch vehicle fairing. Performance needs developed under the study are traceable to a variety of reference designs including options for a monolithic primary mirror.

  4. High Flux Isotope Reactor cold neutron source reference design concept

    SciTech Connect

    Selby, D.L.; Lucas, A.T.; Hyman, C.R.

    1998-05-01

    In February 1995, Oak Ridge National Laboratory`s (ORNL`s) deputy director formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. In May 1995, a team was formed to examine the feasibility of retrofitting a liquid hydrogen (LH{sub 2}) cold source facility into an existing HFIR beam tube. The results of this feasibility study indicated that the most practical location for such a cold source was the HB-4 beam tube. This location provides a potential flux environment higher than the Institut Laue-Langevin (ILL) vertical cold source and maximizes the space available for a future cold neutron guide hall expansion. It was determined that this cold neutron beam would be comparable, in cold neutron brightness, to the best facilities in the world, and a decision was made to complete a preconceptual design study with the intention of proceeding with an activity to install a working LH{sub 2} cold source in the HFIR HB-4 beam tube. During the development of the reference design the liquid hydrogen concept was changed to a supercritical hydrogen system for a number of reasons. This report documents the reference supercritical hydrogen design and its performance. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and testing, (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the conceptual design phase and establishes the baseline reference concept.

  5. Mooring Design for the Floating Oscillating Water Column Reference Model

    SciTech Connect

    Brefort, Dorian; Bull, Diana L.

    2014-09-01

    To reduce the price of the reference Backward Bent Duct Buoy (BBDB), a study was done analyzing the effects of reducing the mooring line length, and a new mooring design was developed. It was found that the overall length of the mooring lines could be reduced by 1290 meters, allowing a significant price reduction of the system. In this paper, we will first give a description of the model and the storm environment it will be subject to. We will then give a recommendation for the new mooring system, followed by a discussion of the severe weather simulation results, and an analysis of the conservative and aggressive aspects of the design.

  6. The Reference Design for the ILC, Costs, and What's Next

    SciTech Connect

    Barish, Barry

    2007-03-26

    A Reference Design for the International Linear Collider was recently released. The scale of the ILC is such that it must be built by an international collaboration and the design is the culmination of a unique global effort. Through ICFA, a decision was made to base the design on superconducting RF technology and then the Global Design Effort (GDE) was created to coordinate the actual accelerator design toward a construction proposal. The reference design establishes all the features of the machine, and defines both the R&D program and engineering design that will now follow over the next few years.

  7. Establishment of reference standards in biosimilar studies.

    PubMed

    Zhang, Aijing; Tzeng, Jung-Ying; Chow, Shein-Chung

    2013-07-31

    When an innovative biological product goes off-patent, biopharmaceutical or biotechnological companies may file an application for regulatory approval of biosimilar products. In practice, however, important information on the innovative (reference) product may not be available for assessment. Thus, it is important to first establish a reference standard while assessing biosimilarity between a biosimilar product and the reference product. In this paper, reference standard is established through the biosimilarity index approach based on a reference-replicated study (or R-R study), in which the reference product is compared with itself under various scenarios. The reference standard can then be used for assessing the degree of similarity between the test and reference drugs in biosimilar studies.

  8. Human Factors Experimental Design and Analysis Reference

    DTIC Science & Technology

    2007-07-01

    and R2Adj – PRESS Statistic – Mallows C(p) A linear regression model that includes all predictors investigated may not be the best model in terms of...as the Adjusted Coefficient of Determination, R2Adj, the PRESS statistic, and Mallows C(p) value. Human Factors Experimental Design and Analysis...equations with highest R2 using R2Adj, PRESS, and Mallows C(p) • Evaluation – Cumbersome as number of X’s increase 10 X’s = (210-1) = 1,023 Regression

  9. Backfill LA Reference Design Feature Evaluation

    SciTech Connect

    Kramer, Norman

    1999-11-17

    Backfill is one of the design features of the repository to be considered for License Application (LA). The objective of this report is to discuss the benefits and liabilities to the repository of the inclusion of backfill in emplacement drifts. Backfill may act as a barrier to water flow, may reduce the waste dissolution rate, and can provide structural protection for the waste package. However, installation of the backfill material can be costly in terms of time, money, and human effort. The scope of this report is to: (1) Analyze the behavior of backfill materials following the intrusion of groundwater for influxes of 1 to 300 mm per year. The report will demonstrate dispersion of groundwater intrusions into backfill over an extended time period when seismic activity and consolidation may cause the potential for liquefaction and settlement of the backfill material. (2) Review the thermal effects of backfill on material behavior. (3) Analyze the effect of rockfall on the performance of backfill and the depth of backfill required to protect waste packages under backfill. (4) Review radiological and heating conditions on placement of backfill. Subsurface Nuclear Safety personnel will perform calculations to determine the radiation reduction-time relationship and shielding capacity of backfill. (5) Evaluate the effects of ventilation on cooling of emplacement drifts and dusting potential. (6) Evaluate drift conditions and configurations to determine the suitability of backfilling methodology. (7) Perform cost assessment of backfill material placement. (8) Evaluate the feature with criteria that will be supplied by the License Application Design Selection (LADS) Team. This report does not discuss backfill for sealing of ramps, shafts and mains but is limited to backfill in emplacement drifts.

  10. Consideration of design and calibration of terrestrial reference solar cells

    NASA Technical Reports Server (NTRS)

    Weizer, V. G.

    1976-01-01

    A discussion is presented on the problems encountered in the design of a reference cell that meets basic criteria, starting with basic design considerations, and proceeding with the precautions taken to ensure a global monitoring capability. The effects of the variations in atmospheric conditions on the calibration and use of reference cells are presented along with a discussion of the simplifications brought about by the use of spectrally matched test and reference cells. Finally, a method of matching test modules and arrays to reference cells by a red/blue response ratio technique is described.

  11. Richards Barrier LA Reference Design Feature Evaluation

    SciTech Connect

    N.E. Kramer

    1999-11-17

    The Richards Barrier is one of the design features of the repository to be considered for the License Application (LA), Richards was a soil scientist who first described the diversion of moisture between two materials with different hydrologic properties. In this report, a Richards Barrier is a special type of backfill with a fine-grained material (such as sand) overlaying a coarse-grained material (such as gravel). Water that enters an emplacement drift will first encounter the fine-grained material and be transported around the coarse-grained material covering the waste package, thus protecting the waste package from contact with most of the groundwater. The objective of this report is to discuss the benefits and liabilities to the repository by the inclusion of a Richards Barrier type backfill in emplacement drifts. The Richards Barrier can act as a barrier to water flow, can reduce the waste package material dissolution rate, limit mobilization of the radionuclides, and can provide structural protection for the waste package. The scope of this report is to: (1) Analyze the behavior of barrier materials following the intrusion of groundwater for influxes of 1 to 300 mm per year. The report will demonstrate diversion of groundwater intrusions into the barrier over an extended time period when seismic activity and consolidation may cause the potential for liquefaction and settlement of the Richards Barrier. (2) Review the thermal effects of the Richards Barrier on material behavior. (3) Analyze the effect of rockfall on the performance of the Richards Barrier and the depth of the barrier required to protect waste packages under the barrier. (4) Review radiological and heating conditions on placement of multiple layers of the barrier. Subsurface Nuclear Safety personnel will perform calculations to determine the radiation reduction-time relationship and shielding capacity of the barrier. (5) Evaluate the effects of ventilation on cooling of emplacement drifts and

  12. Artificial Intelligence for VHSIC Systems Design (AIVD) User Reference Manual

    DTIC Science & Technology

    1988-12-01

    AD-A259 518 C;ý I RESEARCH TRIANGLE INSTITUTE ARTIFICIAL INTELLIGENCE FOR IVHSIC SYSTEMS DESIGN (AIVD) DTIC USER REFERENCE MANUAL * ScELECTE fl2...Report 14. SUBJECT TERMS IS. MUMBER OF PAGES VHSIC, Software/hardware codesign, Artificial Intelligence graph transformation, ADAS 14. PRICE CODE 17... ARTIFICIAL INTELLIGENCE FOR I VHSIC SYSTEMS DESIGN (AIVD) USER REFERENCE MANUAL December 1988 I Department of the Army ,,’ U.S. Army Electronics Research

  13. Reference design description for a geologic repository: Revision 01

    SciTech Connect

    1997-09-01

    This document describes the current design expectations for a potential geologic repository that could be located at Yucca Mountain in Nevada. This Reference Design Description (RDD) looks at the surface and subsurface repository and disposal container design. Additionally, it reviews the expected long-term performance of the potential repository. In accordance with current legislation, the reference design for the potential repository does not include an interim storage option. The reference design presented allows the disposal of highly radioactive material received from government-owned spent fuel custodian sites; produces high-level waste sites, and commercial spent fuel sites. All design elements meet current federal, state, and local regulations governing the disposal of high-level radioactive waste and protection of the public and the environment. Due to the complex nature of developing a repository, the design will be created in three phases to support Viability Assessment, License Application, and construction. This document presents the current reference design. It will be updated periodically as the design progresses. Some of the details presented here may change significantly as more cost-effective solutions, technical advancements, or changes to requirements are identified.

  14. Jewish Studies: A Guide to Reference Sources.

    ERIC Educational Resources Information Center

    McGill Univ., Montreal (Quebec). McLennan Library.

    An annotated bibliography to the reference sources for Jewish Studies in the McLennan Library of McGill University (Canada) is presented. Any titles in Hebrew characters are listed by their transliterated equivalents. There is also a list of relevant Library of Congress Subject Headings. General reference sources listed are: encyclopedias,…

  15. STS ancillary equipment study. User reference book

    NASA Technical Reports Server (NTRS)

    Plough, J. A.

    1977-01-01

    A record of what is currently known about STS ancillary equipment is presented in this user-oriented design so that a potential user may evaluate whether he could use the described ancillary equipment or if he would need to design and fabricate a payload-unique item. References that the user can use to obtain additional details and requirements to aid in his evaluation and decision are included.

  16. LOXT mirror design study

    NASA Technical Reports Server (NTRS)

    Vanspeybroeck, L.; Antrim, W.; Boyd, D.; Giacconi, R.; Sinnamon, G.; Stille, F.

    1972-01-01

    The final report for the large orbiting X-ray telescope (LOXT) high resolution mirror design study is presented. The following tasks were performed: (1) Generation of a reference and alternate preliminary design for the LOXT high resolution mirror assembly, which will meet the LOXT scientific requirements, and are within the present state of the art of materials and fabrication techniques. (2) Measurement, in X-rays, of the scattering properties of a variety of optical flats, embodying materials, coatings, and polishing techniques which might be applicable to the flight configuration LOXT high resolution mirror. (3) Preparation of a procurement specification for a paraboloid test mirror of the size of the innermost paraboloid of the high resolution mirror assembly, including the design requirements for the reference design evolved from this preliminary design study. The results of the engineering and scientific analysis and the conclusions drawn are presented. The procurement specification for the test mirror is included.

  17. Design Reference Missions for Deep-Space Optical Communication

    NASA Astrophysics Data System (ADS)

    Breidenthal, J.; Abraham, D.

    2016-05-01

    We examined the potential, but uncertain, NASA mission portfolio out to a time horizon of 20 years, to identify mission concepts that potentially could benefit from optical communication, considering their communications needs, the environments in which they would operate, and their notional size, weight, and power constraints. A set of 12 design reference missions was selected to represent the full range of potential missions. These design reference missions span the space of potential customer requirements, and encompass the wide range of applications that an optical ground segment might eventually be called upon to serve. The design reference missions encompass a range of orbit types, terminal sizes, and positions in the solar system that reveal the chief system performance variables of an optical ground segment, and may be used to enable assessments of the ability of alternative systems to meet various types of customer needs.

  18. Human Exploration of Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.

    2009-01-01

    This document reviews the Design Reference Architecture (DRA) for human exploration of Mars. The DRA represents the current best strategy for human missions. The DRA is not a formal plan, but provides a vision and context to tie current systems and technology developments to potential missions to Mars, and it also serves as a benchmark against which alternative architectures can be measured. The document also reviews the objectives and products of the 2007 study that was to update NASA's human Mars mission reference architecture, assess strategic linkages between lunar and Mars strategies, develop an understanding of methods for reducing cost/risk of human missions through investment in research, technology development and synergy with other exploration plans. There is also a review of the process by which the DRA will continue to be refined. The unique capacities of human exploration is reviewed. The possible goals and objectives of the first three human missions are presented, along with the recommendation that the mission involve a long stay visiting multiple sites.The deployment strategy is outlined and diagrammed including the pre-deployment of the many of the material requirements, and a six crew travel to Mars on a six month trajectory. The predeployment and the Orion crew vehicle are shown. The ground operations requirements are also explained. Also the use of resources found on the surface of Mars is postulated. The Mars surface exploration strategy is reviewed, including the planetary protection processes that are planned. Finally a listing of the key decisions and tenets is posed.

  19. Radioisotope Power Systems Reference Book for Mission Designers and Planners

    NASA Technical Reports Server (NTRS)

    Lee, Young; Bairstow, Brian

    2015-01-01

    The RPS Program's Program Planning and Assessment (PPA) Office commissioned the Mission Analysis team to develop the Radioisotope Power Systems (RPS) Reference Book for Mission Planners and Designers to define a baseline of RPS technology capabilities with specific emphasis on performance parameters and technology readiness. The main objective of this book is to provide RPS technology information that could be utilized by future mission concept studies and concurrent engineering practices. A progress summary from the major branches of RPS technology research provides mission analysis teams with a vital tool for assessing the RPS trade space, and provides concurrent engineering centers with a consistent set of guidelines for RPS performance characteristics. This book will be iterated when substantial new information becomes available to ensure continued relevance, serving as one of the cornerstone products of the RPS PPA Office. This book updates the original 2011 internal document, using data from the relevant publicly released RPS technology references and consultations with RPS technologists. Each performance parameter and RPS product subsection has been reviewed and cleared by at least one subject matter representative. A virtual workshop was held to reach consensus on the scope and contents of the book, and the definitions and assumptions that should be used. The subject matter experts then reviewed and updated the appropriate sections of the book. The RPS Mission Analysis Team then performed further updates and crosschecked the book for consistency. Finally, a second virtual workshop was held to ensure all subject matter experts and stakeholders concurred on the contents.

  20. Reference design description for a geologic repository. Revision 02

    SciTech Connect

    1999-01-01

    This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada. It describes the proposed design for a surface facility, subsurface repository, and waste packaging; it also presents the current design of the key engineering systems for the final four phases: operations, monitoring, closure, and postclosure. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. In accordance with current law, this design does not include an interim storage option. This document has six major sections. Section 1 describes the physical layout of the proposed repository. The second section describes the 4-phase evolution of the development of the proposed repository. Section 3 describes the reception of waste from offsite locations. The fourth section details the various systems that will package the waste and move it below ground as well as safety monitoring and closure. Section 5 describes the systems (both physical and analytical) that ensure continued safety after closure. The final section offers design options that may be adopted to increase the margin of safety.

  1. Human Exploration of Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.

    2010-01-01

    This paper provides a summary of the Mars Design Reference Architecture 5.0 (DRA 5.0), which is the latest in a series of NASA Mars reference missions. It provides a vision of one potential approach to human Mars exploration. The reference architecture provides a common framework for future planning of systems concepts, technology development, and operational testing as well as Mars robotic missions, research that is conducted on the International Space Station, and future lunar exploration missions. This summary the Mars DRA 5.0 provides an overview of the overall mission approach, surface strategy and exploration goals, as well as the key systems and challenges for the first three human missions to Mars.

  2. Human Exploration of Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G.; Hoffman, Stephen J.; Beaty, David W.

    2009-01-01

    This paper provides a summary of the 2007 Mars Design Reference Architecture 5.0 (DRA 5.0), which is the latest in a series of NASA Mars reference missions. It provides a vision of one potential approach to human Mars exploration including how Constellation systems can be used. The reference architecture provides a common framework for future planning of systems concepts, technology development, and operational testing as well as Mars robotic missions, research that is conducted on the International Space Station, and future lunar exploration missions. This summary the Mars DRA 5.0 provides an overview of the overall mission approach, surface strategy and exploration goals, as well as the key systems and challenges for the first three human missions to Mars.

  3. Next-Generation Space Telescope design reference mission

    NASA Astrophysics Data System (ADS)

    Smith, Eric P.; Mather, John C.; Stockman, Hervey S.; Bely, Pierre Y.; Stiavelli, Massimo; Burg, Richard

    1998-08-01

    The Next Generation Space Telescope (NGST) Design Reference Mission (DRM) represents a suite of potential astronomical programs and targets along with their expected physical properties, and desired observation modes. This broad science program is being used to drive the observatory design in a way as fundamental as traditional engineering parameters. Astronomers use the DRM to communicate their desires in a quantitative fashion to the engineers who will eventually construct the observatory. The DRM is also the primary tool used to measure the relative value of NGST mission architectures and technological readiness of the program. Specifically, the fraction of the DRM completed by a given observatory configuration in a given time is, to first order, a measure of the value of the design. Those designs which complete a higher fraction of the observations listed below are more capable than those complete lesser fractions.

  4. Basic coaxial mass driver reference design. [electromagnetic lunar launch

    NASA Technical Reports Server (NTRS)

    Kolm, H. H.

    1977-01-01

    The reference design for a basic coaxial mass driver is developed to illustrate the principles and optimization procedures on the basis of numerical integration by programmable pocket calculators. The four inch caliber system uses a single-coil bucket and a single-phase propulsion track with discrete coils, separately energized by capacitors. An actual driver would use multiple-coil buckets and an oscillatory multi-phase drive system. Even the basic, table-top demonstration system should in principle be able to achieve accelerations in the 1,000 m/sq sec range. Current densities of the order of 25 ka/sq cm, continuously achievable only in superconductors, are carried by an ordinary aluminum bucket coil for a short period in order to demonstrate the calculated acceleration. Ultimately the system can be lengthened and provided with a magnetically levitated, superconducting bucket to study levitation dynamics under quasi-steady-state conditions, and to approach lunar escape velocity in an evacuated tube.

  5. Updated reference design of a liquid metal cooled tandem mirror fusion breeder

    SciTech Connect

    Berwald, D.H.; Whitley, R.H.; Garner, J.K.; Gromada, R.J.; McCarville, T.J.; Moir, R.W.; Lee, J.D.; Bandini, B.R.; Fulton, F.J.; Wong, C.P.C.; Maya, I.; Hoot, C.G.; Schultz, K.R.; Miller, L.G.; Beeston, J.M.; Harris, B.L.; Westman, R.A.; Ghoniem, N.M.; Orient, G.; Wolfer, M.; DeVan, J.H.; Torterelli, P.

    1985-09-01

    Detailed studies of key techinical issues for liquid metal cooled fusion breeder (fusion-fission hybrid blankets) have been performed during the period 1983-4. Based upon the results of these studies, the 1982 reference liquid metal cooled tandem mirror fusion breeder blanket design was updated and is described. The updated reference blankets provides increased breeding and lower technological risk in comparison with the original reference blanket. In addition to the blanket design revisions, a plant concept, cost, and fuel cycle economics assessment is provided. The fusion breeder continues to promise an economical source of fissile fuel for the indefinite future.

  6. Reference Model 2: %22Rev 0%22 Rotor Design.

    SciTech Connect

    Barone, Matthew F.; Berg, Jonathan Charles; Griffith, Daniel

    2011-12-01

    The preliminary design for a three-bladed cross-flow rotor for a reference marine hydrokinetic turbine is presented. A rotor performance design code is described, along with modifications to the code to allow prediction of blade support strut drag as well as interference between two counter-rotating rotors. The rotor is designed to operate in a reference site corresponding to a riverine environment. Basic rotor performance and rigid-body loads calculations are performed to size the rotor elements and select the operating speed range. The preliminary design is verified with a simple finite element model that provides estimates of bending stresses during operation. A concept for joining the blades and support struts is developed and analyzed with a separate finite element analysis. Rotor mass, production costs, and annual energy capture are estimated in order to allow calculations of system cost-of-energy. Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd Evaluation Only. Created with Aspose.Pdf.Kit. Copyright 2002-2011 Aspose Pty Ltd

  7. Content Analysis of Virtual Reference Data: Reshaping Library Website Design.

    PubMed

    Fan, Suhua Caroline; Welch, Jennifer M

    2016-01-01

    An academic health sciences library wanted to redesign its website to provide better access to health information in the community. Virtual reference data were used to provide information about user searching behavior. This study analyzed three years (2012-2014) of virtual reference data, including e-mail questions, text messaging, and live chat transcripts, to evaluate the library website for redesigning, especially in areas such as the home page, patrons' terminology, and issues prompting patrons to ask for help. A coding system based on information links in the current library website was created to analyze the data.

  8. Importance of reference gene selection for articular cartilage mechanobiology studies

    PubMed Central

    Al-Sabah, A.; Stadnik, P.; Gilbert, S.J.; Duance, V.C.; Blain, E.J.

    2016-01-01

    Summary Objective Identification of genes differentially expressed in mechano-biological pathways in articular cartilage provides insight into the molecular mechanisms behind initiation and/or progression of osteoarthritis (OA). Quantitative PCR (qPCR) is commonly used to measure gene expression, and is reliant on the use of reference genes for normalisation. Appropriate validation of reference gene stability is imperative for accurate data analysis and interpretation. This study determined in vitro reference gene stability in articular cartilage explants and primary chondrocytes subjected to different compressive loads and tensile strain, respectively. Design The expression of eight commonly used reference genes (18s, ACTB, GAPDH, HPRT1, PPIA, RPL4, SDHA and YWHAZ) was determined by qPCR and data compared using four software packages (comparative delta-Ct method, geNorm, NormFinder and BestKeeper). Calculation of geometric means of the ranked weightings was carried out using RefFinder. Results Appropriate reference gene(s) for normalisation of mechanically-regulated transcript levels in articular cartilage tissue or isolated chondrocytes were dependent on experimental set-up. SDHA, YWHAZ and RPL4 were the most stable genes whilst glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and to a lesser extent Hypoxanthine-guanine phosphoribosyltransferase (HPRT), showed variable expression in response to load, demonstrating their unsuitability in such in vitro studies. The effect of using unstable reference genes to normalise the expression of aggrecan (ACAN) and matrix metalloproteinase 3 (MMP3) resulted in inaccurate quantification of these mechano-sensitive genes and erroneous interpretation/conclusions. Conclusion This study demonstrates that commonly used ‘reference genes’ may be unsuitable for in vitro cartilage chondrocyte mechanobiology studies, reinforcing the principle that careful validation of reference genes is essential prior to each experiment to

  9. Reference Design for a Simple, Durable and Refuelable Interplanetary Spacecraft

    NASA Astrophysics Data System (ADS)

    McConnell, B. S.; Tolley, A. M.

    This article describes a reference design for interplanetary vessels, composed mostly of water, that utilize simplified RF engines for low thrust, long duration propulsion, and hydrogen peroxide for short duration, high thrust burns. The electrothermal engines are designed to heat a wide range of liquid materials, possibly also milled solids or surface dusts. The system emphasizes simple components and processes based on older technologies, many well known since the 1960s, that are understandable, can process a variety of materials, and are easily serviced in flight. The goal is to radically simplify systems and their inter-dependencies, to a point where a reasonably skilled person can learn to operate these vessels, not unlike a sailboat, and to eliminate many design and testing bottlenecks in their construction. The use of water, or hydrogen peroxide generated in situ from that water, is multiply advantageous because it can be used for structure, consumption, irrigation, radiation and debris shielding, and thermal regulation, and thus greatly reduce dead weight by creating an almost fully consumable ship. This also enables the ship to utilize a wide range of in situ materials, and eventually obtain reaction mass from lower gravity sites. The ability to switch between low thrust, constant power and high thrust, short duration maneuvers will enable these ships to travel freely and reach many interesting destinations throughout the solar system. One can think of them as “spacecoaches”, not unlike the prairie schooners of the Old West, which were rugged, serviceable by tradesmen, and easily maintained.

  10. Reference Beam Pattern Design for Frequency Invariant Beamforming Based on Fast Fourier Transform

    PubMed Central

    Zhang, Wang; Su, Tao

    2016-01-01

    In the field of fast Fourier transform (FFT)-based frequency invariant beamforming (FIB), there is still an unsolved problem. That is the selection of the reference beam to make the designed wideband pattern frequency invariant (FI) over a given frequency range. This problem is studied in this paper. The research shows that for a given array, the selection of the reference beam pattern is determined by the number of sensors and the ratio of the highest frequency to the lowest frequency of the signal (RHL). The length of the weight vector corresponding to a given reference beam pattern depends on the reference frequency. In addition, the upper bound of the weight length to ensure the FI property over the whole frequency band of interest is also given. When the constraints are added to the reference beam, it does not affect the FI property of the designed wideband beam as long as the symmetry of the reference beam is ensured. Based on this conclusion, a scheme for reference beam design is proposed. PMID:27669242

  11. Reference Beam Pattern Design for Frequency Invariant Beamforming Based on Fast Fourier Transform.

    PubMed

    Zhang, Wang; Su, Tao

    2016-09-22

    In the field of fast Fourier transform (FFT)-based frequency invariant beamforming (FIB), there is still an unsolved problem. That is the selection of the reference beam to make the designed wideband pattern frequency invariant (FI) over a given frequency range. This problem is studied in this paper. The research shows that for a given array, the selection of the reference beam pattern is determined by the number of sensors and the ratio of the highest frequency to the lowest frequency of the signal (RHL). The length of the weight vector corresponding to a given reference beam pattern depends on the reference frequency. In addition, the upper bound of the weight length to ensure the FI property over the whole frequency band of interest is also given. When the constraints are added to the reference beam, it does not affect the FI property of the designed wideband beam as long as the symmetry of the reference beam is ensured. Based on this conclusion, a scheme for reference beam design is proposed.

  12. With Reference to Reference Genes: A Systematic Review of Endogenous Controls in Gene Expression Studies

    PubMed Central

    Chapman, Joanne R.; Waldenström, Jonas

    2015-01-01

    The choice of reference genes that are stably expressed amongst treatment groups is a crucial step in real-time quantitative PCR gene expression studies. Recent guidelines have specified that a minimum of two validated reference genes should be used for normalisation. However, a quantitative review of the literature showed that the average number of reference genes used across all studies was 1.2. Thus, the vast majority of studies continue to use a single gene, with β-actin (ACTB) and/or glyceraldehyde 3-phosphate dehydrogenase (GAPDH) being commonly selected in studies of vertebrate gene expression. Few studies (15%) tested a panel of potential reference genes for stability of expression before using them to normalise data. Amongst studies specifically testing reference gene stability, few found ACTB or GAPDH to be optimal, whereby these genes were significantly less likely to be chosen when larger panels of potential reference genes were screened. Fewer reference genes were tested for stability in non-model organisms, presumably owing to a dearth of available primers in less well characterised species. Furthermore, the experimental conditions under which real-time quantitative PCR analyses were conducted had a large influence on the choice of reference genes, whereby different studies of rat brain tissue showed different reference genes to be the most stable. These results highlight the importance of validating the choice of normalising reference genes before conducting gene expression studies. PMID:26555275

  13. With Reference to Reference Genes: A Systematic Review of Endogenous Controls in Gene Expression Studies.

    PubMed

    Chapman, Joanne R; Waldenström, Jonas

    2015-01-01

    The choice of reference genes that are stably expressed amongst treatment groups is a crucial step in real-time quantitative PCR gene expression studies. Recent guidelines have specified that a minimum of two validated reference genes should be used for normalisation. However, a quantitative review of the literature showed that the average number of reference genes used across all studies was 1.2. Thus, the vast majority of studies continue to use a single gene, with β-actin (ACTB) and/or glyceraldehyde 3-phosphate dehydrogenase (GAPDH) being commonly selected in studies of vertebrate gene expression. Few studies (15%) tested a panel of potential reference genes for stability of expression before using them to normalise data. Amongst studies specifically testing reference gene stability, few found ACTB or GAPDH to be optimal, whereby these genes were significantly less likely to be chosen when larger panels of potential reference genes were screened. Fewer reference genes were tested for stability in non-model organisms, presumably owing to a dearth of available primers in less well characterised species. Furthermore, the experimental conditions under which real-time quantitative PCR analyses were conducted had a large influence on the choice of reference genes, whereby different studies of rat brain tissue showed different reference genes to be the most stable. These results highlight the importance of validating the choice of normalising reference genes before conducting gene expression studies.

  14. NASA'S RPS Design Reference Mission Set for Solar System Exploration

    NASA Astrophysics Data System (ADS)

    Balint, Tibor S.

    2007-01-01

    NASA's 2006 Solar System Exploration (SSE) Strategic Roadmap identified a set of proposed large Flagship, medium New Frontiers and small Discovery class missions, addressing key exploration objectives. These objectives respond to the recommendations by the National Research Council (NRC), reported in the SSE Decadal Survey. The SSE Roadmap is down-selected from an over-subscribed set of missions, called the SSE Design Reference Mission (DRM) set Missions in the Flagship and New Frontiers classes can consider Radioisotope Power Systems (RPSs), while small Discovery class missions are not permitted to use them, due to cost constraints. In line with the SSE DRM set and the SSE Roadmap missions, the RPS DRM set represents a set of missions, which can be enabled or enhanced by RPS technologies. At present, NASA has proposed the development of two new types of RPSs. These are the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), with static power conversion; and the Stirling Radioisotope Generator (SRG), with dynamic conversion. Advanced RPSs, under consideration for possible development, aim to increase specific power levels. In effect, this would either increase electric power generation for the same amount of fuel, or reduce fuel requirements for the same power output, compared to the proposed MMRTG or SRG. Operating environments could also influence the design, such that an RPS on the proposed Titan Explorer would use smaller fins to minimize heat rejection in the extreme cold environment; while the Venus Mobile Explorer long-lived in-situ mission would require the development of a new RPS, in order to tolerate the extreme hot environment, and to simultaneously provide active cooling to the payload and other electric components. This paper discusses NASA's SSE RPS DRM set, in line with the SSE DRM set. It gives a qualitative assessment regarding the impact of various RPS technology and configuration options on potential mission architectures, which could

  15. NASA's RPS Design Reference Mission Set for Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Balint, Tibor S.

    2007-01-01

    NASA's 2006 Solar System Exploration (SSE) Strategic Roadmap identified a set of proposed large Flagship, medium New Frontiers and small Discovery class missions, addressing key exploration objectives. These objectives respond to the recommendations by the National Research Council (NRC), reported in the SSE Decadal Survey. The SSE Roadmap is down-selected from an over-subscribed set of missions, called the SSE Design Reference Mission (DRM) set. Missions in the Flagship and New Frontiers classes can consider Radioisotope Power Systems (RPSs), while small Discovery class missions are not permitted to use them, due to cost constraints. In line with the SSE DRM set and the SSE Roadmap missions, the RPS DRM set represents a set of missions, which can be enabled or enhanced by RPS technologies. At present, NASA has proposed the development of two new types of RPSs. These are the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), with static power conversion; and the Stirling Radioisotope Generator (SRG), with dynamic conversion. Advanced RPSs, under consideration for possible development, aim to increase specific power levels. In effect, this would either increase electric power generation for the same amount of fuel, or reduce fuel requirements for the same power output, compared to the proposed MMRTG or SRG. Operating environments could also influence the design, such that an RPS on the proposed Titan Explorer would use smaller fins to minimize heat rejection in the extreme cold environment; while the Venus Mobile Explorer long-lived in-situ mission would require the development of a new RPS, in order to tolerate the extreme hot environment, and to simultaneously provide active cooling to the payload and other electric components. This paper discusses NASA's SSE RPS DRM set, in line with the SSE DRM set. It gives a qualitative assessment regarding the impact of various RPS technology and configuration options on potential mission architectures, which could

  16. Conceptual spacecraft and arcjet propulsion system design for the SP-100 interim reference mission

    NASA Technical Reports Server (NTRS)

    Zafran, S.; Bell, M. W. J.

    1990-01-01

    An arcjet propulsion system, delivering 7.5 N thrust, was defined for the SP-100 Space Reactor Power System Interim Reference Mission. Conceptual design trades and configuration studies of a spacecraft suitable for the mission were performed to the extent necessary to define propulsion system requirements and interfaces. The propulsion system design is based on the use of 30-kW, constricted arc, ammonia arcjet engines operating in parallel during orbit boost from low earth to geosynchronous orbit.

  17. Biological reference materials for extracellular vesicle studies.

    PubMed

    Valkonen, S; van der Pol, E; Böing, A; Yuana, Y; Yliperttula, M; Nieuwland, R; Laitinen, S; Siljander, P R M

    2017-02-15

    Extracellular vesicles (EVs) mediate normal physiological homeostasis and pathological processes by facilitating intercellular communication. Research of EVs in basic science and clinical settings requires both methodological standardization and development of reference materials (RM). Here, we show insights and results of biological RM development for EV studies. We used a three-step approach to find and develop a biological RM. First, a literature search was done to find candidates for biological RMs. Second, a questionnaire was sent to EV researchers querying the preferences for RM and their use. Third, a biological RM was selected, developed, characterized, and evaluated. The responses to the survey demonstrated a clear and recognized need for RM optimized for the calibration of EV measurements. Based on the literature, naturally occurring and produced biological RM, such as virus particles and liposomes, were proposed as RM. However, none of these candidate RMs have properties completely matching those of EVs, such as size and refractive index distribution. Therefore, we evaluated the use of nanoerythrosomes (NanoE), vesicles produced from erythrocytes, as a potential biological RM. The strength of NanoE is their resemblance to EVs. Compared to the erythrocyte-derived EVs (eryEVs), NanoE have similar morphology, a similar refractive index (1.37), larger diameter (70% of the NanoE are over 200nm), and increased positive staining for CD235a and lipids (Di-8-ANEPPS) (58% and 67% in NanoE vs. 21% and 45% in eryEVs, respectively). Altogether, our results highlight the general need to develop and validate new RM with similar physical and biochemical properties as EVs to standardize EV measurements between instruments and laboratories.

  18. A Sneak Preview of the E-ELT Design Reference Science Plan Questionnaire Results

    NASA Astrophysics Data System (ADS)

    Kissler-Patig, M.; Küpcü Yoldaş, A.; Liske, J.

    2009-12-01

    The European Extremely Large Telescope is in its detailed design phase until the end of 2010. During this period, the telescope design is being consolidated and instrument and operation concepts are being studied. The scientific users are feeding back requirements into the project in numerous ways. One of them, the Design Reference Science Plan, was an opportunity for the entire community to provide direct feedback to the project. Here, we summarise the first results from this study. The full report will appear in the first half of 2010.

  19. Staffing by Design: A Methodology for Staffing Reference

    ERIC Educational Resources Information Center

    Ward, David; Phetteplace, Eric

    2012-01-01

    The growth in number and kind of online reference services has resulted in both new users consulting library research services as well as new patterns of service use. Staffing in-person and virtual reference services desks adequately requires a systematic analysis of patterns of use across service points in order to successfully meet fluctuating…

  20. Spintronic Memristor Based Temperature Sensor Design with CMOS Current Reference

    DTIC Science & Technology

    2012-03-01

    torques acting on its free layer magnetization vector, which is significantly impacted by thermal fluctuations. Therefore, the memristance, a.k.a. the...when HP lab firstly discovered it through a TiO2 thin-film structure [2]. Memristors show many promising characteristics as the next- generation data...As illustrated in Figure 2(a), the device is composed of two ferromagnetic layers : reference and free layers . The reference layer is coupled to a

  1. Space platform reference mission studies overview

    NASA Technical Reports Server (NTRS)

    Harrison, J. K.

    1981-01-01

    The design requirements for three major space platform systems are identified. The three were the Science and Applications Space Platform (SASP), the Geostationary Platform (GSP), and the Satellite Power System (SPS). Because the SASP and GSP were assumed to require no advanced technology for their development an advanced version of each was selected on which to base the design requirements. The SPS represented the opposite development state hence a nearer term test article was selected on which to base the requirements. The development period for these missions is estimated.

  2. Reference design and operations for deep borehole disposal of high-level radioactive waste.

    SciTech Connect

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-10-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  3. Large Synoptic Survey Telescope: From Science Drivers to Reference Design

    SciTech Connect

    Ivezic, Z.; Axelrod, T.; Brandt, W.N.; Burke, D.L.; Claver, C.F.; Connolly, A.; Cook, K.H.; Gee, P.; Gilmore, D.K.; Jacoby, S.H.; Jones, R.L.; Kahn, S.M.; Kantor, J.P.; Krabbendam, V.; Lupton, R.H.; Monet, D.G.; Pinto, P.A.; Saha, A.; Schalk, T.L.; Schneider, D.P.; Strauss, Michael A.; /Washington U., Seattle, Astron. Dept. /LSST Corp. /Penn State U., Astron. Astrophys. /KIPAC, Menlo Park /NOAO, Tucson /LLNL, Livermore /UC, Davis /Princeton U., Astrophys. Sci. Dept. /Naval Observ., Flagstaff /Arizona U., Astron. Dept. - Steward Observ. /UC, Santa Cruz /Harvard U. /Johns Hopkins U. /Illinois U., Urbana

    2011-10-14

    In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg{sup 2} with {delta} < +34.5{sup o}, and will be imaged multiple times in six bands, ugrizy, covering the wavelength range 320-1050 nm. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We describe how the

  4. An Engineering Design Reference Mission for a Future Large-Aperture UVOIR Space Observatory

    NASA Astrophysics Data System (ADS)

    Thronson, Harley A.; Bolcar, Matthew R.; Clampin, Mark; Crooke, Julie A.; Redding, David; Rioux, Norman; Stahl, H. Philip

    2016-01-01

    From the 2010 NRC Decadal Survey and the NASA Thirty-Year Roadmap, Enduring Quests, Daring Visions, to the recent AURA report, From Cosmic Birth to Living Earths, multiple community assessments have recommended development of a large-aperture UVOIR space observatory capable of achieving a broad range of compelling scientific goals. Of these priority science goals, the most technically challenging is the search for spectroscopic biomarkers in the atmospheres of exoplanets in the solar neighborhood. Here we present an engineering design reference mission (EDRM) for the Advanced Technology Large-Aperture Space Telescope (ATLAST), which was conceived from the start as capable of breakthrough science paired with an emphasis on cost control and cost effectiveness. An EDRM allows the engineering design trade space to be explored in depth to determine what are the most demanding requirements and where there are opportunities for margin against requirements. Our joint NASA GSFC/JPL/MSFC/STScI study team has used community-provided science goals to derive mission needs, requirements, and candidate mission architectures for a future large-aperture, non-cryogenic UVOIR space observatory. The ATLAST observatory is designed to operate at a Sun-Earth L2 orbit, which provides a stable thermal environment and excellent field of regard. Our reference designs have emphasized a serviceable 36-segment 9.2 m aperture telescope that stows within a five-meter diameter launch vehicle fairing. As part of our cost-management effort, this particular reference mission builds upon the engineering design for JWST. Moreover, it is scalable to a variety of launch vehicle fairings. Performance needs developed under the study are traceable to a variety of additional reference designs, including options for a monolithic primary mirror.

  5. An Earth-Moon System Trajectory Design Reference Catalog

    NASA Technical Reports Server (NTRS)

    Folta, David; Bosanac, Natasha; Guzzetti, Davide; Howell, Kathleen C.

    2014-01-01

    As demonstrated by ongoing concept designs and the recent ARTEMIS mission, there is, currently, significant interest in exploiting three-body dynamics in the design of trajectories for both robotic and human missions within the Earth-Moon system. The concept of an interactive and 'dynamic' catalog of potential solutions in the Earth-Moon system is explored within this paper and analyzed as a framework to guide trajectory design. Characterizing and compiling periodic and quasi-periodic solutions that exist in the circular restricted three-body problem may offer faster and more efficient strategies for orbit design, while also delivering innovative mission design parameters for further examination.

  6. The IST-05 Reference Model in Evaluation and Design

    DTIC Science & Technology

    2004-04-01

    bits and bytes in a computer memory. To avoid the need for telepathy in manipulating and understanding the data, the IST-05 Reference Model... synthetic views from digital elevation maps and from photographic imagery, but today’s technology makes this possible. Example 2: Instructions for the arrival

  7. 7 CFR 801.12 - Design requirements incorporated by reference.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... by reference. (a) Moisture meters. All moisture meters approved for use in official grain moisture determination and certification shall meet applicable requirements contained in the FGIS Moisture Handbook and the General Code and Grain Moisture Meters Code of the 1991 edition of the National Institute...

  8. 7 CFR 801.12 - Design requirements incorporated by reference.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... by reference. (a) Moisture meters. All moisture meters approved for use in official grain moisture determination and certification shall meet applicable requirements contained in the FGIS Moisture Handbook and the General Code and Grain Moisture Meters Code of the 1991 edition of the National Institute...

  9. 7 CFR 801.12 - Design requirements incorporated by reference.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... by reference. (a) Moisture meters. All moisture meters approved for use in official grain moisture determination and certification shall meet applicable requirements contained in the FGIS Moisture Handbook and the General Code and Grain Moisture Meters Code of the 1991 edition of the National Institute...

  10. 7 CFR 801.12 - Design requirements incorporated by reference.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... by reference. (a) Moisture meters. All moisture meters approved for use in official grain moisture determination and certification shall meet applicable requirements contained in the FGIS Moisture Handbook and the General Code and Grain Moisture Meters Code of the 1991 edition of the National Institute...

  11. A reference model for model-based design of critical infrastructure protection systems

    NASA Astrophysics Data System (ADS)

    Shin, Young Don; Park, Cheol Young; Lee, Jae-Chon

    2015-05-01

    Today's war field environment is getting versatile as the activities of unconventional wars such as terrorist attacks and cyber-attacks have noticeably increased lately. The damage caused by such unconventional wars has also turned out to be serious particularly if targets are critical infrastructures that are constructed in support of banking and finance, transportation, power, information and communication, government, and so on. The critical infrastructures are usually interconnected to each other and thus are very vulnerable to attack. As such, to ensure the security of critical infrastructures is very important and thus the concept of critical infrastructure protection (CIP) has come. The program to realize the CIP at national level becomes the form of statute in each country. On the other hand, it is also needed to protect each individual critical infrastructure. The objective of this paper is to study on an effort to do so, which can be called the CIP system (CIPS). There could be a variety of ways to design CIPS's. Instead of considering the design of each individual CIPS, a reference model-based approach is taken in this paper. The reference model represents the design of all the CIPS's that have many design elements in common. In addition, the development of the reference model is also carried out using a variety of model diagrams. The modeling language used therein is the systems modeling language (SysML), which was developed and is managed by Object Management Group (OMG) and a de facto standard. Using SysML, the structure and operational concept of the reference model are designed to fulfil the goal of CIPS's, resulting in the block definition and activity diagrams. As a case study, the operational scenario of the nuclear power plant while being attacked by terrorists is studied using the reference model. The effectiveness of the results is also analyzed using multiple analysis models. It is thus expected that the approach taken here has some merits

  12. Multi-point Adjoint-Based Design of Tilt-Rotors in a Noninertial Reference Frame

    NASA Technical Reports Server (NTRS)

    Jones, William T.; Nielsen, Eric J.; Lee-Rausch, Elizabeth M.; Acree, Cecil W.

    2014-01-01

    Optimization of tilt-rotor systems requires the consideration of performance at multiple design points. In the current study, an adjoint-based optimization of a tilt-rotor blade is considered. The optimization seeks to simultaneously maximize the rotorcraft figure of merit in hover and the propulsive efficiency in airplane-mode for a tilt-rotor system. The design is subject to minimum thrust constraints imposed at each design point. The rotor flowfields at each design point are cast as steady-state problems in a noninertial reference frame. Geometric design variables used in the study to control blade shape include: thickness, camber, twist, and taper represented by as many as 123 separate design variables. Performance weighting of each operational mode is considered in the formulation of the composite objective function, and a build up of increasing geometric degrees of freedom is used to isolate the impact of selected design variables. In all cases considered, the resulting designs successfully increase both the hover figure of merit and the airplane-mode propulsive efficiency for a rotor designed with classical techniques.

  13. Factors Influencing Digital Reference Triage: A Think-Aloud Study

    ERIC Educational Resources Information Center

    Pomerantz, Jeffrey

    2004-01-01

    This article describes a think-aloud study conducted to identify factors that influence the decisions made by digital reference "triagers" when performing triage on questions received by digital reference services. This study follows and expands on a Delphi study that identified factors that triagers agreed on after the fact of their performance…

  14. Design of zero reference codes by means of a global optimization method

    NASA Astrophysics Data System (ADS)

    Saez Landete, José; Alonso, José; Bernabeu, Eusebio

    2005-01-01

    The grating measurement systems can be used for displacement and angle measurements. They require of zero reference codes to obtain zero reference signals and absolute measures. The zero reference signals are obtained from the autocorrelation of two identical zero reference codes. The design of codes which generate optimum signals is rather complex, especially for larges codes. In this paper we present a global optimization method, a DIRECT algorithm for the design of zero reference codes. This method proves to be a powerful tool for solving this inverse problem.

  15. Design of zero reference codes by means of a global optimization method.

    PubMed

    Saez-Landete, José; Alonso, José; Bernabeu, Eusebio

    2005-01-10

    The grating measurement systems can be used for displacement and angle measurements. They require of zero reference codes to obtain zero reference signals and absolute measures. The zero reference signals are obtained from the autocorrelation of two identical zero reference codes. The design of codes which generate optimum signals is rather complex, especially for larges codes. In this paper we present a global optimization method, a DIRECT algorithm for the design of zero reference codes. This method proves to be a powerful tool for solving this inverse problem.

  16. HYBRID SULFUR PROCESS REFERENCE DESIGN AND COST ANALYSIS

    SciTech Connect

    Gorensek, M.; Summers, W.; Boltrunis, C.; Lahoda, E.; Allen, D.; Greyvenstein, R.

    2009-05-12

    This report documents a detailed study to determine the expected efficiency and product costs for producing hydrogen via water-splitting using energy from an advanced nuclear reactor. It was determined that the overall efficiency from nuclear heat to hydrogen is high, and the cost of hydrogen is competitive under a high energy cost scenario. It would require over 40% more nuclear energy to generate an equivalent amount of hydrogen using conventional water-cooled nuclear reactors combined with water electrolysis compared to the proposed plant design described herein. There is a great deal of interest worldwide in reducing dependence on fossil fuels, while also minimizing the impact of the energy sector on global climate change. One potential opportunity to contribute to this effort is to replace the use of fossil fuels for hydrogen production by the use of water-splitting powered by nuclear energy. Hydrogen production is required for fertilizer (e.g. ammonia) production, oil refining, synfuels production, and other important industrial applications. It is typically produced by reacting natural gas, naphtha or coal with steam, which consumes significant amounts of energy and produces carbon dioxide as a byproduct. In the future, hydrogen could also be used as a transportation fuel, replacing petroleum. New processes are being developed that would permit hydrogen to be produced from water using only heat or a combination of heat and electricity produced by advanced, high temperature nuclear reactors. The U.S. Department of Energy (DOE) is developing these processes under a program known as the Nuclear Hydrogen Initiative (NHI). The Republic of South Africa (RSA) also is interested in developing advanced high temperature nuclear reactors and related chemical processes that could produce hydrogen fuel via water-splitting. This report focuses on the analysis of a nuclear hydrogen production system that combines the Pebble Bed Modular Reactor (PBMR), under development by

  17. Reference Materials in LIS Instruction: A Delphi Study

    ERIC Educational Resources Information Center

    Rabina, Debbie

    2013-01-01

    This paper presents the results of a Delphi study conducted over a two-month period in 2011. The purpose of the study was to identify reference sources that should be covered in basic reference courses taught in LIS programs in the United States. The Delphi method was selected for its appropriateness in soliciting expert opinions and assessing the…

  18. Design of Low Complexity Model Reference Adaptive Controllers

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Schaefer, Jacob; Johnson, Marcus; Nguyen, Nhan

    2012-01-01

    Flight research experiments have demonstrated that adaptive flight controls can be an effective technology for improving aircraft safety in the event of failures or damage. However, the nonlinear, timevarying nature of adaptive algorithms continues to challenge traditional methods for the verification and validation testing of safety-critical flight control systems. Increasingly complex adaptive control theories and designs are emerging, but only make testing challenges more difficult. A potential first step toward the acceptance of adaptive flight controllers by aircraft manufacturers, operators, and certification authorities is a very simple design that operates as an augmentation to a non-adaptive baseline controller. Three such controllers were developed as part of a National Aeronautics and Space Administration flight research experiment to determine the appropriate level of complexity required to restore acceptable handling qualities to an aircraft that has suffered failures or damage. The controllers consist of the same basic design, but incorporate incrementally-increasing levels of complexity. Derivations of the controllers and their adaptive parameter update laws are presented along with details of the controllers implementations.

  19. [Ergonomic technology. Design study].

    PubMed

    Apostol, I; Ciobanu, O

    2007-01-01

    The paper deals with domains and technological developments and related supports that enhance the rehabilitation process. Ergonomic Technology, Rehabilitation Engineering, Accessibility and Assistive technology are factors involved in promoting a greater independence for people with disabilities by designing and developing new devices with improved design and functionality. Results of a device design study for people with disabilities are presented.

  20. A reference pelton turbine - design and efficiency measurements

    NASA Astrophysics Data System (ADS)

    Solemslie, Bjørn W.; Dahlhaug, Ole G.

    2014-03-01

    The Pelton turbine has been subject to a varying degree of research interest since the debut of the technology over a century ago. Despite its age there are gaps in the knowledge concerning the flow mechanisms effecting the flow through the turbine. A Pelton turbine has been designed at the Waterpower Laboratory at NTNU. This has been done in connection to a Ph.D. project focusing on the flow in Pelton turbine buckets. The design of the turbine has been conducted using in-house knowledge in addition to some comments from a turbine producer. To describe the geometry multiple Bezier curves were used and the design strategy aimed to give a smooth and continuous gradient along the main flow directions in the bucket. The turbine has been designed for the operational conditions of the Pelton test rig installed at the Waterpower Laboratory which is a horizontal single jet test rig with a jet diameter(ds) of 35 mm. The diameter(D) of the runner was set to 513 mm and the width(W) of a bucket 114 mm, leading to a D/W ratio of 4.5. Manufacturing of the turbine has been carried out in aluminium and the turbine has undergone efficiency testing and visual inspection during operation at a head of 70 m. The turbine did not performed as expected and the maximum efficiency was found to be 77.75%. The low efficiency is mainly caused by a large amount of water leaving the bucket through the lip and hence transferring close to zero of its energy to the shaft. The reason for the large lip loss is discussed and two possible causes are found; the jet is located too close to the lip, and the inner surface of the bucket does not lead the water away from the lip. The turbine geometry and all data from both measurements and simulations will be available upon request in an effort to increase the amount of available data concerning Pelton turbines.

  1. Design of an ultra-compact reference ULE cavity

    NASA Astrophysics Data System (ADS)

    Didier, Alexandre; Millo, Jacques; Lacroûte, Clément; Ouisse, Morvan; Delporte, Jérôme; Giordano, Vincent; Rubiola, Enrico; Kersalé, Yann

    2016-06-01

    This article presents the design and the conception of an ultra-compact Fabry-Pérot cavity which will be used to develop an ultra-stable laser. The proposed cavity is composed of a 25 mm long ULE spacer with fused silica mirrors. It leads to an expected fractional frequency stability of 1.5 x 10-15 limited by the thermal noise. The chosen geometry leads to an acceleration relative sensitivity below 10-12 /(m/s2) for all directions.

  2. Human Exploration of Mars Design Reference Architecture 5.0, Addendum #2

    NASA Technical Reports Server (NTRS)

    Drake, Bret G. (Editor); Watts Kevin D. (Editor)

    2014-01-01

    This report serves as the second Addendum to NASA-SP-2009-566, "Human Exploration of Mars Design Reference Architecture 5.0." The data and descriptions contained within this Addendum capture some of the key assessments and studies produced since publication of the original document, predominately covering those conducted from 2009 through 2012. The assessments and studies described herein are for the most part independent stand-alone contributions. Effort has not been made to assimilate the findings to provide an updated integrated strategy. That is a recognized future effort. This report should not be viewed as constituting a formal plan for the human exploration of Mars.

  3. Architectural design proposal for a Martian base to continue NASA Mars Design Reference Mission

    NASA Astrophysics Data System (ADS)

    Kozicki, Janek

    The issue of extraterrestrial bases has recently been a very vivid one. There are orbital stations currently existing and humans will travel to Mars around 2030. They will need stations established there, which will provide them the proper living conditions. Firstly, it might be a small module brought from Earth (e.g. NASA Mars Design Reference Mission module (DRM)), in later stages equivalents of Earth houses may be built from local resources. The goal of this paper is to propose an architectural design for an intermediate stage — for a larger habitable unit transported from Earth. It is inspired by terrestrial portable architecture ideas. A pneumatic structure requires small volume during transportation. However, it provides large habitable space after deployment. It is designed for transport by DRM transportation module and its deployment is considerable easy and brief. An architectural solution analogous to a terrestrial house with a studio and a workshop was assumed. Its form was a result of technical and environmental limitations, and the need for an ergonomic interior. The spatial placement of following zones was carefully considered: residential, agricultural and science, as well as a garage with a workshop, transportation routes, and a control and communication center. The issues of Life Support System, energy, food, water and waste recycling were also discussed. This Martian base was designed to be crewed by a team of eight people to stay on Mars for at least 1.5 year. An Open Plan architectural solution was assumed in pneumatic modules, with a high level of modularity. Walls of standardized sizes with zip-fasteners allow free rearrangement of the interior to adapt to a new situation (e.g. damage of one of the pneumatic modules or a psychological ,,need of a change"). The architectural design focuses on ergonomic and psychological aspects of longer stay in hostile Martian environment. This solution provides Martian crew with a comfortable habitable

  4. Time domain and frequency domain design techniques for model reference adaptive control systems

    NASA Technical Reports Server (NTRS)

    Boland, J. S., III

    1971-01-01

    Some problems associated with the design of model-reference adaptive control systems are considered and solutions to these problems are advanced. The stability of the adapted system is a primary consideration in the development of both the time-domain and the frequency-domain design techniques. Consequentially, the use of Liapunov's direct method forms an integral part of the derivation of the design procedures. The application of sensitivity coefficients to the design of model-reference adaptive control systems is considered. An application of the design techniques is also presented.

  5. Study design: the basics.

    PubMed

    Lim, Hyun Ja; Hoffmann, Raymond G

    2007-01-01

    In biomedical research, meaningful conclusions can only be drawn based on data collected from a valid scientific design using appropriate statistical methods. Therefore, the selection of an appropriate study design is important in order to provide an unbiased and scientific evaluation of the research questions. In this chapter, the different kinds of experimental studies commonly used in biology and medicine are introduced. A brief survey of basic experimental study designs, randomization, blinding, possible biases, issues in data analysis, and interpretation of the study results are mainly provided.

  6. Martian Aerocapture Terminal Point Guidance: A Reference Path Optimization Study

    NASA Technical Reports Server (NTRS)

    Ro, Theodore U.; Queen, Eric M.; Striepe, Scott A.

    1999-01-01

    An effective method of terminal point guidance is to employ influence coefficients, which are solved from a set of differential equations adjoint to the linearized perturbations of the equations of motion about a reference trajectory. Hence, to optimize this type of guidance, one must first optimize the reference trajectory that the guidance is based upon. This study concentrates on various methods to optimize a reference trajectory for a Martian aerocapture maneuver, including a parametric analysis and first order gradient method. Resulting reference trajectories were tested in separate 2000 6-DOF Monte Carlo runs, using the Atmospheric Guidance Algorithm Testbed for the Mars Surveyor Program 2001 (MSP '01) Orbiter. These results were compared to an August 1998 study using the same terminal point control guidance algorithm and simulation testbed. Satisfactory improvements over the 1998 study are amply demonstrated.

  7. Superior cross-species reference genes: a blueberry case study.

    PubMed

    Die, Jose V; Rowland, Lisa J

    2013-01-01

    The advent of affordable Next Generation Sequencing technologies has had major impact on studies of many crop species, where access to genomic technologies and genome-scale data sets has been extremely limited until now. The recent development of genomic resources in blueberry will enable the application of high throughput gene expression approaches that should relatively quickly increase our understanding of blueberry physiology. These studies, however, require a highly accurate and robust workflow and make necessary the identification of reference genes with high expression stability for correct target gene normalization. To create a set of superior reference genes for blueberry expression analyses, we mined a publicly available transcriptome data set from blueberry for orthologs to a set of Arabidopsis genes that showed the most stable expression in a developmental series. In total, the expression stability of 13 putative reference genes was evaluated by qPCR and a set of new references with high stability values across a developmental series in fruits and floral buds of blueberry were identified. We also demonstrated the need to use at least two, preferably three, reference genes to avoid inconsistencies in results, even when superior reference genes are used. The new references identified here provide a valuable resource for accurate normalization of gene expression in Vaccinium spp. and may be useful for other members of the Ericaceae family as well.

  8. Energy Efficient Drivepower : Literature Reference List, Volume 2 Design Engineer's Supplement.

    SciTech Connect

    Ula, Sadrul; Jordan, Don L.; Birnbaum, Larry E.

    1993-01-01

    A large number of information sources in the area of the efficient use of drivepower are listed. The main list is for the general user of drivepower systems. The other list is a supplemental reference list for the design engineer.

  9. Energy Efficient Drivepower : Literature Reference List, Volume 2, Design Engineer`s Supplement.

    SciTech Connect

    Ula, Sadrul.; Birnbaum, Larry E.; Jordan, Don

    1992-01-01

    A large number of information sources in the area of the efficient use of drivepower are listed. The main list is for the general user of drivepower systems. The other list is a supplemental reference list for the design engineer.

  10. Cryogenic Propulsion Stage (CPS) Configuration in Support of NASA's Multiple Design Reference Missions (DRMs)

    NASA Technical Reports Server (NTRS)

    Hanna, Stephen G.; Jones, David L.; Creech, Stephen D.; Lawrence, Thomas D.

    2012-01-01

    In support of the National Aeronautics and Space Administration's (NASA) Human Exploration and Operations Mission Directorate (HEOMD), the Space Launch System (SLS) is being designed for safe, affordable, and sustainable human and scientific exploration missions beyond Earth's or-bit (BEO). The SLS Team is tasked with developing a system capable of safely and repeatedly lofting a new fleet of spaceflight vehicles beyond Earth orbit. The Cryogenic Propulsion Stage (CPS) is a key enabler for evolving the SLS capability for BEO missions. This paper reports on the methodology and initial recommendations relative to the CPS, giving a brief retrospective of early studies on this promising propulsion hardware. This paper provides an overview of the requirements development and CPS configuration in support of NASA's multiple Design Reference Missions (DRMs).

  11. An extended protocol for usability validation of medical devices: research design and reference model.

    PubMed

    Schmettow, Martin; Schnittker, Raphaela; Schraagen, Jan Maarten

    2017-03-21

    This paper proposes and demonstrates an extended protocol for usability validation testing of medical devices. A review of currently used methods for the usability evaluation of medical devices revealed two main shortcomings. Firstly, the lack of methods to closely trace the interaction sequences and derive performance measures. Secondly, a prevailing focus on cross-sectional validation studies, ignoring the issues of learnability and training. The U.S. Federal Drug and Food Administration's recent proposal for a validation testing protocol for medical devices is then extended to address these shortcomings: (1) a novel process measure 'normative path deviations' is introduced that is useful for both quantitative and qualitative usability studies and (2) a longitudinal, completely within-subject study design is presented that assesses learnability, training effects and allows analysis of diversity of users. A reference regression model is introduced to analyze data from this and similar studies, drawing upon generalized linear mixed-effects models and a Bayesian estimation approach. The extended protocol is implemented and demonstrated in a study comparing a novel syringe infusion pump prototype to an existing design with a sample of 25 healthcare professionals. Strong performance differences between designs were observed with a variety of usability measures, as well as varying training-on-the-job effects. We discuss our findings with regard to validation testing guidelines, reflect on the extensions and discuss the perspectives they add to the validation process.

  12. Time reference in agrammatic aphasia: A cross-linguistic study

    PubMed Central

    Bastiaanse, Roelien; Bamyaci, Elif; Hsu, Chien-Ju; Lee, Jiyeon; Duman, Tuba Yarbay; Thompson, Cynthia K.

    2015-01-01

    It has been shown across several languages that verb inflection is difficult for agrammatic aphasic speakers. In particular, Tense inflection is vulnerable. Several theoretical accounts for this have been posed, for example, a pure syntactic one suggesting that the Tense node is unavailable due to its position in the syntactic tree (Friedmann & Grodzinsky, 1997); one suggesting that the interpretable features of the Tense node are underspecified (Burchert, Swoboda-Moll, & De Bleser, 2005; Wenzlaff & Clahsen, 2004, 2005); and a morphosemantic one, arguing that the diacritic Tense features are affected in agrammatism (Faroqi–Shah & Dickey, 2009; Lee, Milman, & Thompson, 2008). However recent findings (Bastiaanse, 2008) and a reanalysis of some oral production studies (e.g. Lee et al., 2008; Nanousi, Masterson, Druks, & Atkinson, 2006) suggest that both Tense and Aspect are impaired and, most importantly, reference to the past is selectively impaired, both through simple verb forms (such as simple past in English) and through periphrastic verb forms (such as the present perfect, ‘has V-ed’, in English). It will be argued that reference to the past is discourse linked and reference to the present and future is not (Zagona, 2003, in press). In-line with Avrutin’s (2000) theory that suggests discourse linking is impaired in Broca’s aphasia, the PAst DIscourse LInking Hypothesis (PADILIH) has been formulated. Three predictions were tested: (1) patients with agrammatic aphasia are selectively impaired in use of grammatical morphology associated with reference to the past, whereas, inflected forms which refer to the present and future are relatively spared; (2) this impairment is language-independent; and (3) this impairment will occur in both production and comprehension. Agrammatic Chinese, English and Turkish speakers were tested with the Test for Assessing Reference of Time (TART; Bastiaanse, Jonkers, & Thompson, unpublished). Results showed that both the

  13. Reference Assessment

    ERIC Educational Resources Information Center

    Bivens-Tatum, Wayne

    2006-01-01

    This article presents interesting articles that explore several different areas of reference assessment, including practical case studies and theoretical articles that address a range of issues such as librarian behavior, patron satisfaction, virtual reference, or evaluation design. They include: (1) "Evaluating the Quality of a Chat Service"…

  14. Scaffolding Students' Development of Creative Design Skills: A Curriculum Reference Model

    ERIC Educational Resources Information Center

    Lee, Chien-Sing; Kolodner, Janet L.

    2011-01-01

    This paper provides a framework for promoting creative design capabilities in the context of achieving community goals pertaining to sustainable development among high school students. The framework can be used as a reference model to design formal or out-of-school curriculum units in any geographical region. This theme is chosen due to its…

  15. The use of standardized infinity reference in EEG coherency studies.

    PubMed

    Marzetti, L; Nolte, G; Perrucci, M G; Romani, G L; Del Gratta, C

    2007-05-15

    The study of large scale interactions in the brain from EEG signals is a promising method for the identification of functional networks. However, the validity of a large scale parameter is limited by two factors: the use of a non-neutral reference and the artifactual self-interactions between the measured EEG signals introduced by volume conduction. In this paper, we propose an approach to study large scale EEG coherency in which these factors are eliminated. Artifactual self-interaction by volume conduction is eliminated by using the imaginary part of the complex coherency as a measure of interaction and the Reference Electrode Standardization Technique (REST) is used for the approximate standardization of the reference of scalp EEG recordings to a point at infinity that, being far from all possible neural sources, acts like a neutral virtual reference. The application of our approach to simulated and real EEG data shows that the detection of interaction, as opposed to artifacts due to reference and volume conduction, is a goal that can be achieved from the study of a large scale parameter.

  16. The WFIRST Interim Design Reference Mission: Capabilities, Constraints, and Open Questions

    NASA Technical Reports Server (NTRS)

    Kruk, Jeffrey W.

    2012-01-01

    The Project Office and Science Definition Team for the Wide-Field Infrared Survey Telescope (WFIRST) are in the midst of a pre-Phase A study to establish a Design Reference Mission (DRM). An Interim report was released in June 2011, with a final report due later in 2012. The predicted performance of the Interim DRM Observatory will be described, including optical quality, observing efficiency, and sensitivity for representative observing scenarios. Observing constraints and other limitations on performance will also be presented, with an emphasis on potential Guest Observer programs. Finally, a brief status update will be provided on open trade studies of interest to the scientific community. The final DRM may differ from the Interim DRM presented here. However, the underlying requirements of the scientific programs are not expected to change, hence the capabilities of the IDRM are likely to be maintained even if the implementation changes in significant ways.

  17. Bibliometric study of Medical Reference Services Quarterly, 1982-2009.

    PubMed

    Kenefick, Colleen; Werner, Susan E

    2011-01-01

    Medical Reference Services Quarterly began publication in 1982, covering topics of current interest and practical value to public services librarians in medical and related specialties. Since then, it has expanded in scope to include more aspects of health sciences librarianship. This article is a systematic study of all 428 peer-reviewed articles published from 1982 through 2009, with a comprehensive description of content and a citation analysis. Content is extensively analyzed for article subject, and cited references are examined for subject, type of cited material, and average age. In addition, author, institutional, and regional productivity is determined and ranked.

  18. The Value of Chat Reference Services: A Pilot Study

    ERIC Educational Resources Information Center

    Jacoby, JoAnn; Ward, David; Avery, Susan; Marcyk, Emilia

    2016-01-01

    This article explores student, instructor, and librarian perceptions of chat reference in the context of an introductory composition course. Participants in a mixed-method study responded to an anonymized chat transcript. While student respondents valued speed and efficiency, they were willing to receive instruction and open to questions that…

  19. Environmental Reference Series, Earth and Environmental Studies, Part II.

    ERIC Educational Resources Information Center

    Qutub, Musa, Comp.

    Compiled in this reference work are bibliographic citations for books and articles dealing with the earth and environmental studies. Specific categories are geology, oceanography, meteorology, and astronomy. Items are indexed only by title but information about author, source, and date of publication is also noted. (BL)

  20. Environmental Reference Series, Earth and Environment Studies, Part I.

    ERIC Educational Resources Information Center

    Qutub, Musa, Comp.

    Compiled in this reference work are bibliographic citations for books, articles, films, and organizations dealing with the earth and environmental studies. In addition to the above topics of a general nature, specific categories include food, natural resources, origin of life, recycling, and wastes. Items are indexed only by title but information…

  1. Development of Integrated Programs for Aerospace-vehicle design (IPAD): Reference design process

    NASA Technical Reports Server (NTRS)

    Meyer, D. D.

    1979-01-01

    The airplane design process and its interfaces with manufacturing and customer operations are documented to be used as criteria for the development of integrated programs for the analysis, design, and testing of aerospace vehicles. Topics cover: design process management, general purpose support requirements, design networks, and technical program elements. Design activity sequences are given for both supersonic and subsonic commercial transports, naval hydrofoils, and military aircraft.

  2. Optimal design of optical reference signals by use of a genetic algorithm

    NASA Astrophysics Data System (ADS)

    Saez-Landete, José; Salcedo-Sanz, Sancho; Rosa-Zurera, Manuel; Alonso, José; Bernabeu, Eusebio

    2005-10-01

    A new technique for the generation of optical reference signals with optimal properties is presented. In grating measurement systems a reference signal is needed to achieve an absolute measurement of the position. The optical signal is the autocorrelation of two codes with binary transmittance. For a long time, the design of this type of code has required great computational effort, which limits the size of the code to ˜30 elements. Recently, the application of the dividing rectangles (DIRECT) algorithm has allowed the automatic design of codes up to 100 elements. Because of the binary nature of the problem and the parallel processing of the genetic algorithms, these algorithms are efficient tools for obtaining codes with particular autocorrelation properties. We design optimum zero reference codes with arbitrary length by means of a genetic algorithm enhanced with a restricted search operator.

  3. Human Health and Performance Aspects of the Mars Design Reference Mission

    NASA Technical Reports Server (NTRS)

    Charles, John B.

    2000-01-01

    This paper will describe the current planning for exploration-class missions, emphasizing the medical, and human factors aspects of such expeditions. The details of mission architecture are still under study, but a typical Mars design reference mission comprises a six-month transit from Earth to Mar, eighteen months in residence on Mars, and a six-month transit back to Earth. Physiological stressors will include environmental factors such as prolonged exposure to radiation, weightlessness in transit, and hypogravity and a toxic atmosphere while on Mars. Psychological stressors will include remoteness from Earth, confinement, and potential interpersonal conflicts, all complicated by circadian alterations. Medical risks including trauma must also be considered. Results of planning for assuring human health and performance will be presented.

  4. Operationalization of a Frame of Reference for Studying Organizational Culture in Middle Schools.

    ERIC Educational Resources Information Center

    Daniel, Larry G.

    A frame of reference for studying culture in middle schools was developed. Items for the Middle School Description Survey (MSDS), which was designed to test elements of the ideal middle school culture, were created based on middle school advocacy literature. The items were conceptually categorized according to E. H. Schein's (1985) cultural…

  5. 77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... for Air Pollution Measurement Systems, Volume I,'' EPA/600/R-94/038a and ``Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air Quality Monitoring Program'' EPA-454/B... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New...

  6. The Role of Virtual Reference in Library Web Site Design: A Qualitative Source for Usage Data

    ERIC Educational Resources Information Center

    Powers, Amanda Clay; Shedd, Julie; Hill, Clay

    2011-01-01

    Gathering qualitative information about usage behavior of library Web sites is a time-consuming process requiring the active participation of patron communities. Libraries that collect virtual reference transcripts, however, hold valuable data regarding how the library Web site is used that could benefit Web designers. An analysis of virtual…

  7. An Automated Tool for Developing Experimental Designs: The Computer-Aided Design Reference for Experiments (CADRE)

    DTIC Science & Technology

    2009-01-01

    survey procedures, and cognitive task analysis), system design methods (e.g., focus groups , design guidelines, specifications, and requirements), and...LABORATORY - HRED ATTN AMSRD ARL HR MZ A DAVISON 199 E 4TH ST STE C TECH PARK BLG 2 FT LEONARD WOOD MO 65473-1949 1 ARMY RSCH LABORATORY

  8. Slurry reactor design studies

    SciTech Connect

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. ); Akgerman, A. ); Smith, J.M. )

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  9. Seal design alternatives study

    SciTech Connect

    Van Sambeek, L.L.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information.

  10. Shuttle communications design study

    NASA Technical Reports Server (NTRS)

    Cartier, D. E.

    1975-01-01

    The design and development of a space shuttle communication system are discussed. The subjects considered include the following: (1) Ku-band satellite relay to shuttle, (2) phased arrays, (3) PN acquisition, (4) quadriplexing of direct link ranging and telemetry, (5) communications blackout on launch and reentry, (6) acquisition after blackout on reentry, (7) wideband communications interface with the Ku-Band rendezvous radar, (8) aeroflight capabilities of the space shuttle, (9) a triple multiplexing scheme equivalent to interplex, and (10) a study of staggered quadriphase for use on the space shuttle.

  11. Integrated technology wing design study

    NASA Technical Reports Server (NTRS)

    Hays, A. P.; Beck, W. E.; Morita, W. H.; Penrose, B. J.; Skarshaug, R. E.; Wainfan, B. S.

    1984-01-01

    The technology development costs and associated benefits in applying advanced technology associated with the design of a new wing for a new or derivative trijet with a capacity for 350 passengers and maximum range of 8519 km, entering service in 1990 were studied. The areas of technology are: (1) airfoil technology; (2) planform parameters; (3) high lift; (4) pitch active control system; (5) all electric systems; (6) E to 3rd power propulsion; (7) airframe/propulsion integration; (8) graphite/epoxy composites; (9) advanced aluminum alloys; (10) titanium alloys; and (11) silicon carbide/aluminum composites. These technologies were applied to the reference aircraft configuration. Payoffs were determined for block fuel reductions and net value of technology. These technologies are ranked for the ratio of net value of technology (NVT) to technology development costs.

  12. Bias due to composite reference standards in diagnostic accuracy studies.

    PubMed

    Schiller, Ian; van Smeden, Maarten; Hadgu, Alula; Libman, Michael; Reitsma, Johannes B; Dendukuri, Nandini

    2016-04-30

    Composite reference standards (CRSs) have been advocated in diagnostic accuracy studies in the absence of a perfect reference standard. The rationale is that combining results of multiple imperfect tests leads to a more accurate reference than any one test in isolation. Focusing on a CRS that classifies subjects as disease positive if at least one component test is positive, we derive algebraic expressions for sensitivity and specificity of this CRS, sensitivity and specificity of a new (index) test compared with this CRS, as well as the CRS-based prevalence. We use as a motivating example the problem of evaluating a new test for Chlamydia trachomatis, an asymptomatic disease for which no gold-standard test exists. As the number of component tests increases, sensitivity of this CRS increases at the expense specificity, unless all tests have perfect specificity. Therefore, such a CRS can lead to significantly biased accuracy estimates of the index test. The bias depends on disease prevalence and accuracy of the CRS. Further, conditional dependence between the CRS and index test can lead to over-estimation of index test accuracy estimates. This commonly-used CRS combines results from multiple imperfect tests in a way that ignores information and therefore is not guaranteed to improve over a single imperfect reference unless each component test has perfect specificity, and the CRS is conditionally independent of the index test. When these conditions are not met, as in the case of C. trachomatis testing, more realistic statistical models should be researched instead of relying on such CRSs.

  13. Design Of A SCRAMJET Nozzle With Streamline Tracing Technique And Reference Temerature Methode

    NASA Astrophysics Data System (ADS)

    Riehmer, J.; Gulhan, A.

    2011-05-01

    This study presents a method to find an optimal shape of a three-dimensional supersonic nozzle for a rectangular scramjet combustion chamber with rounded edges by taking into account the skin friction effects. The geometric and flow constraints are defined within the German DFG GRK 1095/2 project and the designed nozzle will be part of a scramjet demonstrator configuration [1]. The nozzle inlet conditions are mean values of the combustion chamber exit conditions with the assumption of a constant specific heat ratio. To generate the shape of the nozzle a streamline tracing technique is applied to an axis-symmetric flow field calculated by the Method of Characteristics (MOC). Skin friction in relatively high pressure supersonic flow from the combustion chamber is very dominant and cannot be neglected in the design process. Therefore the skin friction is calculated using the Reference Temperature Method (RTM) and used for the determination of the thrust and moment vectors. This allows considering viscous effects without boundary layer calculations. With this approach an optimal truncated ideal nozzle contour which yields the geometric constraints can be derived. For the validation of this method comparative calculations have been carried out with the DLR code TAU on an exemplary axis-symmetric supersonic nozzle for different flow conditions. Results showed a good agreement. Finally for the three-dimensional nozzle the analytical solution for the inviscous and viscous case provided comparable data like TAU simulations. Further simplifications of the approach for an efficient three-dimensional nozzle design will be addressed in the paper.

  14. Automated Question Triage for Social Reference: A Study of Adopting Decision Factors from Digital Reference

    ERIC Educational Resources Information Center

    Park, Jong Do

    2013-01-01

    The increasing popularity of Social Reference (SR) services has enabled a corresponding growth in the number of users engaging in them as well as in the number of questions submitted to the services. However, the efficiency and quality of the services are being challenged because a large quantity of the questions have not been answered or…

  15. Conceptual design optimization study

    NASA Technical Reports Server (NTRS)

    Hollowell, S. J.; Beeman, E. R., II; Hiyama, R. M.

    1990-01-01

    The feasibility of applying multilevel functional decomposition and optimization techniques to conceptual design of advanced fighter aircraft was investigated. Applying the functional decomposition techniques to the conceptual design phase appears to be feasible. The initial implementation of the modified design process will optimize wing design variables. A hybrid approach, combining functional decomposition techniques for generation of aerodynamic and mass properties linear sensitivity derivatives with existing techniques for sizing mission performance and optimization, is proposed.

  16. Thermal design and test results for SUNLITE ultra-stable reference cavity

    NASA Technical Reports Server (NTRS)

    Amundsen, Ruth M.

    1991-01-01

    SUNLITE (Stanford University-NASA Laser In-Space Technology Experiment) is a space-based experiment which uses a reference cavity to provide a stable frequency reference for a terahertz laser oscillator. Thermal stability of the cavity is a key factor in attaining a stable narrow-linewidth laser beam. The mount which is used to support and align the cavity will provide thermal isolation from the environment. The baseline requirement for thermal stability of the cavity is 0.025 C/min, but the design is directed toward achieving stability well beyond this requirement to improve the science data gained. A prototype of the cavity mount was fabricated and tested to characterize the thermal performance. The thermal vacuum test involved stable high-resolution temperature measurements and stable baseplate temperature control over long durations. Based on test data, the cavity mount design satisfies the severe requirement for the cavity thermal stability.

  17. Thermionic Reactor Design Studies

    SciTech Connect

    Schock, Alfred

    1994-06-01

    During the 1960's and early 70's the author performed extensive design studies, analyses, and tests aimed at thermionic reactor concepts that differed significantly from those pursued by other investigators. Those studies, like most others under Atomic Energy Commission (AEC and DOE) and the National Aeronautics and Space Administration (NASA) sponsorship, were terminated in the early 1970's. Some of this work was previously published, but much of it was never made available in the open literature. U.S. interest in thermionic reactors resumed in the early 80's, and was greatly intensified by reports about Soviet ground and flight tests in the late 80's. This recent interest resulted in renewed U.S. thermionic reactor development programs, primarily under Department of Defense (DOD) and Department of Energy (DOE) sponsorship. Since most current investigators have not had an opportunity to study all of the author's previous work, a review of the highlights of that work may be of value to them. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling. Where the author's concepts differed from the later Topaz-2 design was in the relative location of the emitter and the collector. Placing the fueled emitter on the outside of the cylindrical diodes permits much higher axial conductances to reduce ohmic losses in the electrodes of full

  18. Analysis of Improved Reference Design for a Nuclear-Driven High Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect

    Edwin A. Harvego; James E. O'Brien; Michael G. McKellar

    2010-06-01

    The use of High Temperature Electrolysis (HTE) for the efficient production of hydrogen without the greenhouse gas emissions associated with conventional fossil-fuel hydrogen production techniques has been under investigation at the Idaho National Engineering Laboratory (INL) for the last several years. The activities at the INL have included the development, testing and analysis of large numbers of solid oxide electrolysis cells, and the analyses of potential plant designs for large scale production of hydrogen using an advanced Very-High Temperature Reactor (VHTR) to provide the process heat and electricity to drive the electrolysis process. The results of these system analyses, using the UniSim process analysis software, have shown that the HTE process, when coupled to a VHTR capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to produce the large quantities of hydrogen needed to meet future energy and transportation needs with hydrogen production efficiencies in excess of 50%. In addition, economic analyses performed on the INL reference plant design, optimized to maximize the hydrogen production rate for a 600 MWt VHTR, have shown that a large nuclear-driven HTE hydrogen production plant can to be economically competitive with conventional hydrogen production processes, particularly when the penalties associated with greenhouse gas emissions are considered. The results of this research led to the selection in 2009 of HTE as the preferred concept in the U.S. Department of Energy (DOE) hydrogen technology down-selection process. However, the down-selection process, along with continued technical assessments at the INL, has resulted in a number of proposed modifications and refinements to improve the original INL reference HTE design. These modifications include changes in plant configuration, operating conditions and individual component designs. This paper describes the resulting new INL reference design and presents

  19. SENIORLAB: a prospective observational study investigating laboratory parameters and their reference intervals in the elderly

    PubMed Central

    Risch, Martin; Nydegger, Urs; Risch, Lorenz

    2017-01-01

    Abstract Background: In clinical practice, laboratory results are often important for making diagnostic, therapeutic, and prognostic decisions. Interpreting individual results relies on accurate reference intervals and decision limits. Despite the considerable amount of resources in clinical medicine spent on elderly patients, accurate reference intervals for the elderly are rarely available. The SENIORLAB study set out to determine reference intervals in the elderly by investigating a large variety of laboratory parameters in clinical chemistry, hematology, and immunology. Methods/design: The SENIORLAB study is an observational, prospective cohort study. Subjectively healthy residents of Switzerland aged 60 years and older were included for baseline examination (n = 1467), where anthropometric measurements were taken, medical history was reviewed, and a fasting blood sample was drawn under optimal preanalytical conditions. More than 110 laboratory parameters were measured, and a biobank was set up. The study participants are followed up every 3 to 5 years for quality of life, morbidity, and mortality. The primary aim is to evaluate different laboratory parameters at age-related reference intervals. The secondary aims of this study include the following: identify associations between different parameters, identify diagnostic characteristics to diagnose different circumstances, identify the prevalence of occult disease in subjectively healthy individuals, and identify the prognostic factors for the investigated outcomes, including mortality. Discussion: To obtain better grounds to justify clinical decisions, specific reference intervals for laboratory parameters of the elderly are needed. Reference intervals are obtained from healthy individuals. A major obstacle when obtaining reference intervals in the elderly is the definition of health in seniors because individuals without any medical condition and any medication are rare in older adulthood. Reference

  20. Control system design for the large space systems technology reference platform

    NASA Technical Reports Server (NTRS)

    Edmunds, R. S.

    1982-01-01

    Structural models and classical frequency domain control system designs were developed for the large space systems technology (LSST) reference platform which consists of a central bus structure, solar panels, and platform arms on which a variety of experiments may be mounted. It is shown that operation of multiple independently articulated payloads on a single platform presents major problems when subarc second pointing stability is required. Experiment compatibility will be an important operational consideration for systems of this type.

  1. Integrated Design and Production Reference Integration with ArchGenXML V1.00

    SciTech Connect

    Barter, R H

    2004-07-20

    ArchGenXML is a tool that allows easy creation of Zope products through the use of Archetypes. The Integrated Design and Production Reference (IDPR) should be highly configurable in order to meet the needs of a diverse engineering community. Ease of configuration is key to the success of IDPR. The purpose of this paper is to describe a method of using a UML diagram editor to configure IDPR through ArchGenXML and Archetypes.

  2. Design of bandgap reference circuits in a 65 nm CMOS technology for HL-LHC applications

    NASA Astrophysics Data System (ADS)

    Traversi, G.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Ratti, L.; Re, V.

    2015-02-01

    This work is concerned with the design and characterization of bandgap reference circuits capable of operating with a power supply of 1.2 V in view of applications to HL-LHC experiments. Due to the harsh environment foreseen for these devices, different solutions have been considered and implemented in a 65 nm CMOS technology. Together with a conventional structure which exploits bipolar devices, a smaller solution based on pn diodes and a version with MOS transistors biased in weak inversion region are included. This paper intends to describe and compare the features of the different circuits designed.

  3. Design of two-dimensional zero reference codes with cross-entropy method.

    PubMed

    Chen, Jung-Chieh; Wen, Chao-Kai

    2010-06-20

    We present a cross-entropy (CE)-based method for the design of optimum two-dimensional (2D) zero reference codes (ZRCs) in order to generate a zero reference signal for a grating measurement system and achieve absolute position, a coordinate origin, or a machine home position. In the absence of diffraction effects, the 2D ZRC design problem is known as the autocorrelation approximation. Based on the properties of the autocorrelation function, the design of the 2D ZRC is first formulated as a particular combination optimization problem. The CE method is then applied to search for an optimal 2D ZRC and thus obtain the desirable zero reference signal. Computer simulation results indicate that there are 15.38% and 14.29% reductions in the second maxima value for the 16x16 grating system with n(1)=64 and the 100x100 grating system with n(1)=300, respectively, where n(1) is the number of transparent pixels, compared with those of the conventional genetic algorithm.

  4. Developing Areas Studies: A Guide to Reference Sources.

    ERIC Educational Resources Information Center

    McGill Univ., Montreal (Quebec). McLennan Library.

    This multi-disciplinary annotated bibliography introduces students to reference resources on developing nations. The collection looks at reference works on developing areas of the world as a whole. The reference collection contains many specialized subject bibliographies that may be identified by a keyword search. Sections of the bibliography…

  5. Analysis of the LSC microbunching instability in MaRIE linac reference design

    SciTech Connect

    Yampolsky, Nikolai

    2016-09-22

    In this report we estimate the effect of the microbunching instability in the MaRIE XFEL linac. The reference design for the linac is described in a separate report. The parameters of the L1, L2, and L3 linacs as well as BC1 and BC2 bunch compressors were the same as in the referenced report. The beam dynamics was assumed to be linear along the accelerator (which is a reasonable assumption for estimating the effect of the microbunching instability). The parameters of the bunch also match the parameters described in the referenced report. Additionally, it was assumed that the beam radius is equal to R = 100 m and does not change along linac. This assumption needs to be revisited at later studies. The beam dynamics during acceleration was accounted in the matrix formalism using a Matlab code. The input parameters for the linacs are: RF peak gradient, RF frequency, RF phase, linac length, and initial beam energy. The energy gain and the imposed chirp are calculated based on the RF parameters self-consistently. The bunch compressors are accounted in the matrix formalism as well. Each chicane is characterized by the beam energy and the R56 matrix element. It was confirmed that the linac and beam parameters described previously provide two-stage bunch compression with compression ratios of 10 and 20 resulting in the bunch of 3kA peak current.

  6. Modular antenna design study

    NASA Technical Reports Server (NTRS)

    Ribble, J. W.

    1981-01-01

    The mechanical design of a modular antenna concept was developed sufficiently to allow manufacture of a working demonstration model of a module, to predict mass properties, and to make performance estimates for antenna reflectors composed of these modules. The primary features of this concept are: (1) each module is an autonomous structural element which can be attached to adjacent modules through a three point connection; (2) the upper surface is a folding hexagonal truss plate mechanism which serves as the supporting structure for a reflective surface; and (3) the entire truss and surface can be folded into a cylindrical envelope in which all truss elements are essentially parallel. The kinematic studies and engineering demonstration model fully verified the deployment kinematics, stowing philosophy, and deployment sequencing for large antenna modules. It was established that such modules can be stowed in packages as small as 25 cm in diameter, using 1.27 cm diameter structural tubes. The development activity indicates that this deployable modular approach towards building large structures in space will support erection of 450 m apertures for operation up to 3 GHz with a single space shuttle flight.

  7. Planetary benchmarks. [structural design criteria for radar reference devices on planetary surfaces

    NASA Technical Reports Server (NTRS)

    Uphoff, C.; Staehle, R.; Kobrick, M.; Jurgens, R.; Price, H.; Slade, M.; Sonnabend, D.

    1978-01-01

    Design criteria and technology requirements for a system of radar reference devices to be fixed to the surfaces of the inner planets are discussed. Offshoot applications include the use of radar corner reflectors as landing beacons on the planetary surfaces and some deep space applications that may yield a greatly enhanced knowledge of the gravitational and electromagnetic structure of the solar system. Passive retroreflectors with dimensions of about 4 meters and weighing about 10 kg are feasible for use with orbiting radar at Venus and Mars. Earth-based observation of passive reflectors, however, would require very large and complex structures to be delivered to the surfaces. For Earth-based measurements, surface transponders offer a distinct advantage in accuracy over passive reflectors. A conceptual design for a high temperature transponder is presented. The design appears feasible for the Venus surface using existing electronics and power components.

  8. High density wireless EEG prototype: Design and evaluation against reference equipment.

    PubMed

    Rossi, Stefano; Patki, Shrishail; Passoni, Marco; Perko, Hannes; Gritsch, Gerhard; Ossenblok, Pauly; Yazicioglu, Refet Firat

    2014-01-01

    A high density wireless electroencephalographic (EEG) platform has been designed. It is able to record up to 64 EEG channels with electrode to tissue impedance (ETI) monitoring. The analog front-end is based on two kinds of low power ASICs implementing the active electrodes and the amplifier. A power efficient compression algorithm enables the use of continuous wireless transmission of data through Bluetooth for real-time monitoring with an overall power consumption of about 350 mW. EEG acquisitions on five subjects (one healthy subject and four patients suffering from epilepsy) have been recorded in parallel with a reference system commonly used in clinical practice and data of the wireless prototype and reference system have been processed with an automatic tool for seizure detection and localization. The false alarm rates (0.1-0.5 events per hour) are comparable between the two system and wireless prototype also detected the seizure correctly and allowed its localization.

  9. Requirements and design reference mission for the WFIRST/AFTA coronagraph instrument

    NASA Astrophysics Data System (ADS)

    Demers, Richard T.; Dekens, Frank; Calvet, Rob; Chang, Zensheu; Effinger, Robert; Ek, Eric; Hovland, Larry; Jones, Laura; Loc, Anthony; Nemati, Bijan; Noecker, Charley; Neville, Timothy; Pham, Hung; Rud, Mike; Tang, Hong; Villalvazo, Juan

    2015-09-01

    The WFIRST-AFTA coronagraph instrument takes advantage of AFTAs 2.4-meter aperture to provide novel exoplanet imaging science at approximately the same instrument cost as an Explorer mission. The AFTA coronagraph also matures direct imaging technologies to high TRL for an Exo-Earth Imager in the next decade. The coronagraph Design Reference Mission (DRM) optical design is based on the highly successful High Contrast Imaging Testbed (HCIT), with modifications to accommodate the AFTA telescope design, service-ability, volume constraints, and the addition of an Integral Field Spectrograph (IFS). In order to optimally satisfy the three science objectives of planet imaging, planet spectral characterization and dust debris imaging, the coronagraph is designed to operate in two different modes: Hybrid Lyot Coronagraph or Shaped Pupil Coronagraph. Active mechanisms change pupil masks, focal plane masks, Lyot masks, and bandpass filters to shift between modes. A single optical beam train can thus operate alternatively as two different coronagraph architectures. Structural Thermal Optical Performance (STOP) analysis predicts the instrument contrast with the Low Order Wave Front Control loop closed. The STOP analysis was also used to verify that the optical/structural/thermal design provides the extreme stability required for planet characterization in the presence of thermal disturbances expected in a typical observing scenario. This paper describes the instrument design and the flow down from science requirements to high level engineering requirements.

  10. Selected, annotated bibliography of studies relevant to the isolation of nuclear wastes. [705 references

    SciTech Connect

    Hyder, L.K.; Fore, C.S.; Vaughan, N.D.; Faust, R.A.

    1980-09-01

    This annotated bibliography of 705 references represents the first in a series to be published by the Ecological Sciences Information Center containing scientific, technical, economic, and regulatory information relevant to nuclear waste isolation. Most references discuss deep geologic disposal, with fewer studies of deep seabed disposal; space disposal is also included. The publication covers both domestic and foreign literature for the period 1954 to 1980. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Envirnmental Transport; General Studies and Reviews; Geology, Hydrology and Site Resources; Regulatory and Economic Aspects; Repository Design and Engineering; Transportation Technology; Waste Production; and Waste Treatment. Specialized data fields have been incorporated to improve the ease and accuracy of locating pertinent references. Specific radionuclides for which data are presented are listed in the Measured Radionuclides field, and specific parameters which affect the migration of these radionuclides are presented in the Measured Parameters field. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. When the author is not given, the corporate affiliation appears first. If these two levels of authorship are not given, the title of the document is used as the identifying level. Indexes are provided for author(s), keywords, subject category, title, geographic location, measured parameters, measured radionuclides, and publication description.

  11. Connecting Online Learners with Diverse Local Practices: The Design of Effective Common Reference Points for Conversation

    ERIC Educational Resources Information Center

    Friend Wise, Alyssa; Padmanabhan, Poornima; Duffy, Thomas M.

    2009-01-01

    This mixed-methods study probed the effectiveness of three kinds of objects (video, theory, metaphor) as common reference points for conversations between online learners (student teachers). Individuals' degree of detail-focus was examined as a potentially interacting covariate and the outcome measure was learners' level of tacit knowledge related…

  12. Architecture as Design Study.

    ERIC Educational Resources Information Center

    Kauppinen, Heta

    1989-01-01

    Explores the use of analogies in architectural design, the importance of Gestalt theory and aesthetic cannons in understanding and being sensitive to architecture. Emphasizes the variation between public and professional appreciation of architecture. Notes that an understanding of architectural process enables students to improve the aesthetic…

  13. A Whole-Transcriptome Approach to Evaluating Reference Genes for Quantitative Gene Expression Studies: A Case Study in Mimulus

    PubMed Central

    Stanton, Kimmy A.; Edger, Patrick P.; Puzey, Joshua R.; Kinser, Taliesin; Cheng, Philip; Vernon, Daniel M.; Forsthoefel, Nancy R.; Cooley, Arielle M.

    2017-01-01

    While quantitative PCR (qPCR) is widely recognized as being among the most accurate methods for quantifying gene expression, it is highly dependent on the use of reliable, stably expressed reference genes. With the increased availability of high-throughput methods for measuring gene expression, whole-transcriptome approaches may be increasingly utilized for reference gene selection and validation. In this study, RNA-seq was used to identify a set of novel qPCR reference genes and evaluate a panel of traditional “housekeeping” reference genes in two species of the evolutionary model plant genus Mimulus. More broadly, the methods proposed in this study can be used to harness the power of transcriptomes to identify appropriate reference genes for qPCR in any study organism, including emerging and nonmodel systems. We find that RNA-seq accurately estimates gene expression means in comparison to qPCR, and that expression means are robust to moderate environmental and genetic variation. However, measures of expression variability were only in agreement with qPCR for samples obtained from a shared environment. This result, along with transcriptome-wide comparisons, suggests that environmental changes have greater impacts on expression variability than on expression means. We discuss how this issue can be addressed through experimental design, and suggest that the ever-expanding pool of published transcriptomes represents a rich and low-cost resource for developing better reference genes for qPCR. PMID:28258113

  14. Thermionic Reactor Design Studies

    SciTech Connect

    Schock, Alfred

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. The present paper describes some of the author's conceptual designs and their rationale, and the special analytical techniques developed to analyze their (thermionic reactor) performance. The basic designs, first published in 1963, are based on single-cell converters, either double-ended diodes extending over the full height of the reactor core or single-ended diodes extending over half the core height. In that respect they are similar to the thermionic fuel elements employed in the Topaz-2 reactor subsequently developed in the Soviet Union, copies of which were recently imported by the U.S. As in the Topaz-2 case, electrically heated steady-state performance tests of the converters are possible before fueling.

  15. A framework and experimental study of an improved VOC/formaldehyde emission reference for environmental chamber tests

    NASA Astrophysics Data System (ADS)

    Wei, Wenjuan; Xiong, Jianyin; Zhao, Weiping; Zhang, Yinping

    2014-01-01

    Environmental chamber systems are usually employed in the testing of volatile organic compound (VOC) and formaldehyde emissions from building materials. The measurement accuracy of environmental chamber systems can be evaluated by VOC/formaldehyde emission references. However, the available VOC/formaldehyde emission references all have some limitations for applications to various scales of chambers. A framework for designing and using a target VOC/formaldehyde emission references to evaluate the performance of chamber systems for measuring VOC/formaldehyde emissions from building materials is studied. Liquid-inner tube diffusion-film-emission (LIFE) reference is improved in this study to meet the requirements of a target VOC/formaldehyde emission reference, such as reliability, similarity as building materials, efficiency for measurement. Equivalent emission characteristic parameters are designed for a toluene LIFE reference to perform similar to a building material. Chamber test of the LIFE reference is made in a 30 m3 stainless steel ventilated environmental chamber at 23 ± 1 °C and 50 ± 5% relative humidity. The experimental data match the predictions using LIFE emission model as well as building material emission model. The improvement of the LIFE reference enables its application for the evaluation of the performance of all kinds of environmental chambers as a general reference in tests of VOCs/formaldehyde emissions from building materials.

  16. A Multicenter Reference Intervals Study for Specific Proteins in China

    PubMed Central

    Qin, Xuzhen; Tang, Guodong; Qiu, Ling; Li, Peng Chang; Xia, Liangyu; Chen, Ming; Tao, Zhihua; Li, Shijun; Liu, Min; Wang, Liang; Gao, Shang; Yu, Songlin; Cheng, Xinqi; Han, Jianhua; Hou, Li’an; Kawano, Reo; Ichihara, Kiyoshi

    2015-01-01

    Abstract A multicenter study conducted in healthy population of 6 cities from the 4 corners and central China for 7 serum-specific proteins to identify the sources of variation and establish the reference intervals on 2 automation platforms. A total of 3148 subjects aged 19 to 64 years old were enrolled in this study to ensure at least 120 participants in each 10-year age group and each city. The majority of samples were transported to central laboratory and measured on both Beckman AU5800 and Immage 800 analytical systems. Three-level nested ANOVA, multiple regression analysis, and the scatter plot were used to explore the variations from sex, age, region, BMI, cigarette smoking, and so on. The latent abnormal value exclusion (LAVE) method was applied at the time of computing RIs as a method for secondary exclusion. Regionality was not observed in any of the immunoassay in China. Variations for sex were significant for IgM among the immune analytes. For CRP and hsCRP results with turbidimetry method (Beckman Coulter AU5800) were lower than the nephelometry method (Beckman Immage). The LAVE method did not affect the RIs computed for the majority of analytes except C4, CRP, and hsCRP. In the scatter plot at the age of 45 years old C3, C4, and IgM reached an inflection point, accordingly RIs were separated by the age group. With the lack of regional differences and the well-standardized status of test results, the RIs of C3, IgG, IgA, IgM derived from this nationwide study can be used for the entire Chinese population. C4, CRP, and hsCRP were affected by different platforms and gender was a significant source of variation for IgM, so they had separated RIs. PMID:26656356

  17. Dietary intake and anthropometric reference values in population studies.

    PubMed

    Arija, Victoria; Pérez Rodrigo, Carmen; Martínez de Vitoria, Emilio; Ortega, Rosa M; Serra-Majem, Luis; Ribas, Lourdes; Aranceta, Javier

    2015-02-26

    In nutritional epidemiology it is essential to have reference values for nutrition and anthropometry in order to compare individual and population data. With respect to reference nutritional intake, the new concept of Dietary Reference Intakes is generated based more on the prevention of chronic diseases than on covering nutritional deficiencies, as would occur in the early Recommendations. As such, the more relevant international organizations incorporated new concepts in their tables, such as the Adequate Intake levels or the Tolerable Upper Intake levels. Currently, the EURRECA recommendations (EURopean micronutrient RECommendations Aligned) are generating reference values for Europe in a transparent, systematic and scientific manner. Using the DRI, health-care authorities formulated nutritional objectives for countries or territories and Dietary Guides to disseminate the dietary advice to the population. Anthropometric assessment continues to be one of the most-used methods for evaluating and monitoring health status, nutritional state and growth in children, not only individuals but also communities. Different organizations have established anthropometric reference patterns of body mass index (BMI) with cut-off points to define overweight and obesity. In children, growth curves have been revised and adapted to the characteristics of healthy children in order to obtain anthropometric reference standards that better reflect optimum growth in children. The Growth Standards for children below 5 years of age of the WHO are a response to these principles, and are widely accepted and used worldwide.

  18. Advanced turbocharger design study program

    NASA Technical Reports Server (NTRS)

    Culy, D. G.; Heldenbrand, R. W.; Richardson, N. R.

    1984-01-01

    The advanced Turbocharger Design Study consisted of: (1) the evaluation of three advanced engine designs to determine their turbocharging requirements, and of technologies applicable to advanced turbocharger designs; (2) trade-off studies to define a turbocharger conceptual design and select the engine with the most representative requirements for turbocharging; (3) the preparation of a turbocharger conceptual design for the Curtiss Wright RC2-32 engine selected in the trade-off studies; and (4) the assessment of market impact and the preparation of a technology demonstration plan for the advanced turbocharger.

  19. A Local Reference For Bar Studies In The Distant Universe

    NASA Astrophysics Data System (ADS)

    Menéndez-Delmestre, Karín; Sheth, Kartik; S4G Team

    2015-08-01

    Stellar bars are present in ~2/3 of nearby spirals and play a critical role in the evolution of their hosts. With the advent of large high-resolution imaging surveys, bar studies are being extended to distant galaxies. However, photometric studies of the distant universe are invariably subject to the effects of band-shifting, the progressive shift of the photometric band to bluer rest-frame wavelengths. In order to reliably characterize the intrinsic evolution of bars with redshift, safe from band-shifting effects, it is necessary to establish a local anchor of how bar properties vary with wavelength. We present a detailed multi-band study of bar properties from UV through mid-infrared for a sample of 16 large nearby barred galaxies. Based on ellipticity and position angle profiles resulting from fitting elliptical isophotes to the 2D light distribution of each galaxy, we find that both the bar length and the bar ellipticity increase at bluer wavebands. We attribute the increase in bar length to the frequent presence of prominent star forming knots at the end of bars: these regions are significantly brighter in bluer bands, resulting in the “artificial” lengthening of the bar. The increase in bar ellipticity, on the other hand, is driven by the bulge size: the bulge, composed primarily of old/red stars, is less prominent at bluer bands, allowing for thinner ellipses to be fit within the bar region. The resulting effect is that bars appear longer and thinner at bluer bands. Although we find that ~50% of the bars disappear in the UV, the results on bar ellipticity and length extend to those cases in which the bar is still visible in the UV. These results imply that careful correction for band-shifting effects is necessary for high-z studies to reliably gauge any intrinsic evolution of the bar properties with redshift. In the light of the ample space-based optical data now available, this study may be used as a reference to implement band-shifting corrections to

  20. Design verification of large time constant thermal shields for optical reference cavities

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Wu, W.; Shi, X. H.; Zeng, X. Y.; Deng, K.; Lu, Z. H.

    2016-02-01

    In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Pérot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing.

  1. Spacecraft and mission design for the SpaceNuclear PowerSystem Reference Mission

    NASA Technical Reports Server (NTRS)

    Deininger, William D.; Vondra, Robert J.

    1987-01-01

    The design and performance of a spacecraft employing arcjet nuclear electric propulsion, suitable for use in the Space Nuclear Power System Reference Mission, are outlined. The vehicle design is based on a 92 kW ammonia arcjet system operating at an I(sp) of 1050 s and an efficiency of 45 percent. The arcjet/gimbal system, power processing unit, and propellant feed-system are described. A 100 kW(e) space nuclear power system is assumed and the spacecraft mass is baselined at 5250 kg excluding the propellant, propellent feed system, and integrated chemical boost engine. A radiation/arcjet efflux diagnostics package is included in the performance analysis. Three mission scenarios are described and are capable of demonstrating the full capability of the space nuclear power source. The missions considered include power system deployment to possible SDI platform orbits and a spacecraft storage mission to an orbit of three times geosynchronous (GEO) with return to GEO corresponding to Delta V's between 7400 m/s, and 7900 m/s. This spacecraft meets the Reference Mission constraint of low developmental risk and is scaleable to power levels projected for future space platforms.

  2. Design verification of large time constant thermal shields for optical reference cavities.

    PubMed

    Zhang, J; Wu, W; Shi, X H; Zeng, X Y; Deng, K; Lu, Z H

    2016-02-01

    In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Pérot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing.

  3. Designing verbal autopsy studies

    PubMed Central

    2010-01-01

    Background Verbal autopsy analyses are widely used for estimating cause-specific mortality rates (CSMR) in the vast majority of the world without high-quality medical death registration. Verbal autopsies -- survey interviews with the caretakers of imminent decedents -- stand in for medical examinations or physical autopsies, which are infeasible or culturally prohibited. Methods and Findings We introduce methods, simulations, and interpretations that can improve the design of automated, data-derived estimates of CSMRs, building on a new approach by King and Lu (2008). Our results generate advice for choosing symptom questions and sample sizes that is easier to satisfy than existing practices. For example, most prior effort has been devoted to searching for symptoms with high sensitivity and specificity, which has rarely if ever succeeded with multiple causes of death. In contrast, our approach makes this search irrelevant because it can produce unbiased estimates even with symptoms that have very low sensitivity and specificity. In addition, the new method is optimized for survey questions caretakers can easily answer rather than questions physicians would ask themselves. We also offer an automated method of weeding out biased symptom questions and advice on how to choose the number of causes of death, symptom questions to ask, and observations to collect, among others. Conclusions With the advice offered here, researchers should be able to design verbal autopsy surveys and conduct analyses with greatly reduced statistical biases and research costs. PMID:20573233

  4. Technical Reference Suite Addressing Challenges of Providing Assurance for Fault Management Architectural Design

    NASA Technical Reports Server (NTRS)

    Fitz, Rhonda; Whitman, Gerek

    2016-01-01

    Research into complexities of software systems Fault Management (FM) and how architectural design decisions affect safety, preservation of assets, and maintenance of desired system functionality has coalesced into a technical reference (TR) suite that advances the provision of safety and mission assurance. The NASA Independent Verification and Validation (IVV) Program, with Software Assurance Research Program support, extracted FM architectures across the IVV portfolio to evaluate robustness, assess visibility for validation and test, and define software assurance methods applied to the architectures and designs. This investigation spanned IVV projects with seven different primary developers, a wide range of sizes and complexities, and encompassed Deep Space Robotic, Human Spaceflight, and Earth Orbiter mission FM architectures. The initiative continues with an expansion of the TR suite to include Launch Vehicles, adding the benefit of investigating differences intrinsic to model-based FM architectures and insight into complexities of FM within an Agile software development environment, in order to improve awareness of how nontraditional processes affect FM architectural design and system health management.

  5. Instant Messaging Reference in an Academic Library: A Case Study.

    ERIC Educational Resources Information Center

    Foley, Marianne

    2002-01-01

    During the 2000-2001 academic year, the General Libraries of the University at Buffalo conducted a pilot project to assess feasibility of providing reference through instant messaging. Describes the project, its implementation, the software used, staffing issues, and publicity efforts. Discusses results of the project in terms of user…

  6. Language Arts: Study and Reference Skills K-12.

    ERIC Educational Resources Information Center

    Instructional Objectives Exchange, Los Angeles, CA.

    The purpose of this revised collection is to help prepare students in kindergarten through high school to do better work in all subjects. Usually one sample item is included for each objective, and it can be simplified or sophisticated according to any age group. This material is divided into two sections: (1) Reference Skills, and (2) Study…

  7. [Study of image quality at various positions of reference scan].

    PubMed

    Takatsu, Yasuo; Umezaki, Yoshie; Miyati, Tosiaki

    2013-03-01

    In magnetic resonance imaging (MRI), we can use sensitivity encoding (SENSE) as a parallel imaging reconstruct from aliasing based on the sensitivity map of each coil element by reference scan. We researched SENSE reconstruction depending on the position of the reference scan. 1.5 T MRI (Achiva, Philips), 32-channel SENSE cardiac coil and rectangular solid phantom (nickel chloride) were used. Seven slices (A to G: from head to foot) were set at the phantom, slice thickness was 1 cm, and each slice interval was 5 cm. When T2 weighted axial images (TR: 3000 ms, TE: 120 ms) were taken, the center of the reference scan (C-Ref) was changed A to G, SENSE factor was changed 1 to 5, and number of signals averaged (NSA) was changed 1 to 3 with fold over suppression. Signal-to-noise ratio (SNR) and coefficient of variation (CV) from 9 regions of interest (ROI) of axial images were calculated. The SNR of slices A and G were lower than the other slices. %CV of slices F with C-Ref D was 69.4% lower than C-Ref A. %CV of slices D to F were higher than the other slices when C-Ref was A. %CV had no relation with SNR. Therefore, a 30 cm area around the center of reference can obtain best SENSE reconstruction.

  8. Characterization of bandgap reference circuits designed for high energy physics applications

    NASA Astrophysics Data System (ADS)

    Traversi, G.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Mattiazzo, S.; Ratti, L.; Re, V.; Riceputi, E.

    2016-07-01

    The objective of this work is to design a high performance bandgap voltage reference circuit in a standard commercial 65 nm CMOS technology capable of operating in harsh radiation environments. A prototype circuit based on three different devices (diode, bipolar transistor and MOSFET) was fabricated and tested. Measurement results show a temperature variation as low as ±3.4 mV over a temperature range of 170 ° C (-30 °C to 140 °C) and a line regulation at room temperature of 5.2%/V. Measured VREF is 690 mV±15 mV (3σ) for 26 samples on the same wafer. Circuits correctly operate with supply voltages in the range from 1.32 V down to 0.78 V. A reference voltage shift of only 7.6 mV (around 1.1%) was measured after irradiation with 10 keV X-rays up to an integrated dose of 225 Mrad (SiO2).

  9. Performance of three 4. 5 m dipoles for SSC reference design D

    SciTech Connect

    Dahl, P.; Cottingham, J.; Fernow, R.; Garber, M.; Ghosh, A.; Goodzeit, C.; Greene, A.; Herrera, J.; Kahn, S.; Kelly, E.

    1985-01-01

    Three 4.5 m long dipoles for Reference Design D of the proposed Superconducting Super Collider have been successfully tested. The magnets are cold-iron (and cold bore) 1-in-1 dipoles, wound with current density-graded high homogeneity NbTi cable in a two-layer cos theta coil of 40 mm inner diameter. The coil is prestressed by 15 mm wide stainless steel collars, and mounted in a circular, split iron yoke of 267 mm outer diameter, supported in a cylindrical yoke containment vessel. At 4.5 K the magnets reached a field of about 6.6T with little training, or the short sample limit of the conductor, and in subcooled (2.6 to 2.4 K) liquid, 8T was achieved. The allowed harmonics were close to the predicted values, and the unallowed harmonics small. The sextupole trim coil operated at eight times the required current without training.

  10. A mussel tissue certified reference material for multiple phycotoxins. Part 1: design and preparation.

    PubMed

    McCarron, Pearse; Emteborg, Håkan; Nulty, Cíara; Rundberget, Thomas; Loader, Jared I; Teipel, Katharina; Miles, Christopher O; Quilliam, Michael A; Hess, Philipp

    2011-05-01

    The development of multi-analyte methods for lipophilic shellfish toxins based on liquid chromatography-mass spectrometry permits rapid screening and analysis of samples for a wide variety of toxins in a single run. Validated methods and appropriate certified reference materials (CRMs) are required to ensure accuracy of results. CRMs are essential for accurate instrument calibration, for assessing the complete analytical method from sample extraction to data analysis and for verifying trueness. However, CRMs have hitherto only been available for single toxin groups. Production of a CRM containing six major toxin groups was achieved through an international collaboration. Preparation of this material, CRM-FDMT1, drew on information from earlier studies as well as improved methods for isolation of toxins, handling bulk tissues and production of reference materials. Previous investigations of stabilisation techniques indicated freeze-drying to be a suitable procedure for preparation of shellfish toxin reference materials and applicable to a wide range of toxins. CRM-FDMT1 was initially prepared as a bulk wet tissue homogenate containing domoic acid, okadaic acid, dinophysistoxins, azaspiracids, pectenotoxin-2, yessotoxin and 13-desmethylspirolide C. The homogenate was then freeze-dried, milled and bottled in aliquots suitable for distribution and analysis. The moisture content and particle size distribution were measured, and determined to be appropriate. A preliminary toxin analysis of the final material showed a comprehensive toxin profile.

  11. Technical Reference Suite Addressing Challenges of Providing Assurance for Fault Management Architectural Design

    NASA Technical Reports Server (NTRS)

    Fitz, Rhonda; Whitman, Gerek

    2016-01-01

    Research into complexities of software systems Fault Management (FM) and how architectural design decisions affect safety, preservation of assets, and maintenance of desired system functionality has coalesced into a technical reference (TR) suite that advances the provision of safety and mission assurance. The NASA Independent Verification and Validation (IV&V) Program, with Software Assurance Research Program support, extracted FM architectures across the IV&V portfolio to evaluate robustness, assess visibility for validation and test, and define software assurance methods applied to the architectures and designs. This investigation spanned IV&V projects with seven different primary developers, a wide range of sizes and complexities, and encompassed Deep Space Robotic, Human Spaceflight, and Earth Orbiter mission FM architectures. The initiative continues with an expansion of the TR suite to include Launch Vehicles, adding the benefit of investigating differences intrinsic to model-based FM architectures and insight into complexities of FM within an Agile software development environment, in order to improve awareness of how nontraditional processes affect FM architectural design and system health management. The identification of particular FM architectures, visibility, and associated IV&V techniques provides a TR suite that enables greater assurance that critical software systems will adequately protect against faults and respond to adverse conditions. Additionally, the role FM has with regard to strengthened security requirements, with potential to advance overall asset protection of flight software systems, is being addressed with the development of an adverse conditions database encompassing flight software vulnerabilities. Capitalizing on the established framework, this TR suite provides assurance capability for a variety of FM architectures and varied development approaches. Research results are being disseminated across NASA, other agencies, and the

  12. Multinomial tree models for assessing the status of the reference in studies of the accuracy of tools for binary classification

    PubMed Central

    Botella, Juan; Huang, Huiling; Suero, Manuel

    2013-01-01

    Studies that evaluate the accuracy of binary classification tools are needed. Such studies provide 2 × 2 cross-classifications of test outcomes and the categories according to an unquestionable reference (or gold standard). However, sometimes a suboptimal reliability reference is employed. Several methods have been proposed to deal with studies where the observations are cross-classified with an imperfect reference. These methods require that the status of the reference, as a gold standard or as an imperfect reference, is known. In this paper a procedure for determining whether it is appropriate to maintain the assumption that the reference is a gold standard or an imperfect reference, is proposed. This procedure fits two nested multinomial tree models, and assesses and compares their absolute and incremental fit. Its implementation requires the availability of the results of several independent studies. These should be carried out using similar designs to provide frequencies of cross-classification between a test and the reference under investigation. The procedure is applied in two examples with real data. PMID:24106484

  13. RAD hard PROM design study

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The results of a preliminary study on the design of a radiation hardened fusible link programmable read-only memory (PROM) are presented. Various fuse technologies and the effects of radiation on MOS integrated circuits are surveyed. A set of design rules allowing the fabrication of a radiation hardened PROM using a Si-gate CMOS process is defined. A preliminary cell layout was completed and the programming concept defined. A block diagram is used to describe the circuit components required for a 4 K design. A design goal data sheet giving target values for the AC, DC, and radiation parameters of the circuit is presented.

  14. REFERENCE MANUAL FOR RASSMIT VERSION 2.1: SUB-SLAB DEPRESSURIZATION SYSTEM DESIGN PERFORMANCE SIMULATION PROGRAM

    EPA Science Inventory

    The report is a reference manual for RASSMlT Version 2.1, a computer program that was developed to simulate and aid in the design of sub-slab depressurization systems used for indoor radon mitigation. The program was designed to run on DOS-compatible personal computers to ensure ...

  15. Study of reference waves in single-exposure generalized phase-shifting digital holography.

    PubMed

    Imbe, Masatoshi; Nomura, Takanori

    2013-06-20

    The appropriate reference wave in single-exposure phase-shifting digital holography using a random-complex-amplitude encoded reference wave is experimentally investigated. Although the reference wave is generalized, the quality of reconstructed images depends on it. Furthermore, when the reference wave satisfies a certain condition, reconstructed images cannot be obtained in this method. After the certain condition is presented, the appropriate condition is studied using a speckle property. Experimental results are given to investigate the relations between the quality of reconstructed images and the sizes of speckles of the reference waves. The results prove that the appropriate reference wave exists in this method.

  16. The X-ray Microcalorimeter Spectrometer (XMS): A Reference Cryogenic Instrument Design for Constellation-X

    NASA Technical Reports Server (NTRS)

    Whitehouse, Paul L.

    2003-01-01

    Constellation-X, a mission now belonging to the Beyond Einstein initiative, is being planned to inherit the x-ray sky from Chandra, XMM-Newton and Astro-E. The first two of four observatories in the constellation will be launched together in 2013 and followed a year later by the launch of the remaining two. The four will independently orbit the Sun-Earth Lagrange point L2. An instrument compliment resides in the Focal Plane Module (FPM) of each observatory 10 m from the Optics Module and consists of three Hard X-ray Telescope (HXT) detectors, a Reflection Grating Spectrometer (RGS) focal plane CCD camera and an X-ray Microcalorimeter Spectrometer (XMS). Instrument awards are scheduled for early 2006. The reference detector for XMS is a 32 x 32 array of microcalorimetric superconducting Transition Edge Sensors (TES). Each pixel casts a variable resistance in a SQUID based multiplexed readout circuit which is coupled to series SQUID arrays for amplification and finally read out by external electronics. A multi-stage continuous ADR will provide the stable 50 mK desired for the TES array and a stable 1 K for the series SQUID arrays while also lifting thermal parasitic and inefficiency loads to a 6 K cryocooler interface. The 6 K cryocooler is expected to emerge from the joint-project Advanced Cryocooler Technology Development Program (ACTDP) in which Constellation-X is an active participant. Project Pre-Formulation activities are marked by extensive technology development necessitating early, but realistic, thermal and cooling load requirements for ADR and ACTDP-cryocooler design points. Such requirements are driven by the encompassing XMS cryostat and ultimately by the thermal environment imposed by the FPM. It is further desired that the XMS instrument be able to operate on its side in the laboratory, with a warm vacuum shell, during an extensive calibration regime. It is that reference system design of the XMS instrument (microcalorimeter, ADR, cryocooler and

  17. Vehicle occupancy detection camera position optimization using design of experiments and standard image references

    NASA Astrophysics Data System (ADS)

    Paul, Peter; Hoover, Martin; Rabbani, Mojgan

    2013-03-01

    Camera positioning and orientation is important to applications in domains such as transportation since the objects to be imaged vary greatly in shape and size. In a typical transportation application that requires capturing still images, inductive loops buried in the ground or laser trigger sensors are used when a vehicle reaches the image capture zone to trigger the image capture system. The camera in such a system is in a fixed position pointed at the roadway and at a fixed orientation. Thus the problem is to determine the optimal location and orientation of the camera when capturing images from a wide variety of vehicles. Methods from Design for Six Sigma, including identifying important parameters and noise sources and performing systematically designed experiments (DOE) can be used to determine an effective set of parameter settings for the camera position and orientation under these conditions. In the transportation application of high occupancy vehicle lane enforcement, the number of passengers in the vehicle is to be counted. Past work has described front seat vehicle occupant counting using a camera mounted on an overhead gantry looking through the front windshield in order to capture images of vehicle occupants. However, viewing rear seat passengers is more problematic due to obstructions including the vehicle body frame structures and seats. One approach is to view the rear seats through the side window. In this situation the problem of optimally positioning and orienting the camera to adequately capture the rear seats through the side window can be addressed through a designed experiment. In any automated traffic enforcement system it is necessary for humans to be able to review any automatically captured digital imagery in order to verify detected infractions. Thus for defining an output to be optimized for the designed experiment, a human defined standard image reference (SIR) was used to quantify the quality of the line-of-sight to the rear seats of

  18. Los Alamos Controlled Air Incinerator for radioactive waste. Volume II. Engineering design reference manual

    SciTech Connect

    Koenig, R.A.; Draper, W.E.; Newmyer, J.M.; Warner, C.L.

    1982-10-01

    This two-volume report is a detailed design and operating documentation of the Los Alamos National Laboratory Controlled Air Incinerator (CAI) and is an aid to technology transfer to other Department of Energy contractor sites and the commercial sector. Volume I describes the CAI process, equipment, and performance, and it recommends modifications based on Los Alamos experience. It provides the necessary information for conceptual design and feasibility studies. Volume II provides descriptive engineering information such as drawings, specifications, calculations, and costs. It aids duplication of the process at other facilities.

  19. A Cross-Cultural Study of Reference Point Adaptation: Evidence from China, Korea, and the US

    ERIC Educational Resources Information Center

    Arkes, Hal R.; Hirshleifer, David; Jiang, Danling; Lim, Sonya S.

    2010-01-01

    We examined reference point adaptation following gains or losses in security trading using participants from China, Korea, and the US. In both questionnaire studies and trading experiments with real money incentives, reference point adaptation was larger for Asians than for Americans. Subjects in all countries adapted their reference points more…

  20. Diffusive Barrier and Getter Under Waste Packages VA Reference Design Feature Evaluations

    SciTech Connect

    MacNeil, K.

    1999-05-24

    This technical document evaluates those aspects of the diffusive barrier and getter features which have the potential for enhancing the performance of the Viability Assessment Reference Design and are also directly related to the key attributes for the repository safety strategy of that design. The effects of advection, hydrodynamic dispersion, and diffusion on the radionuclide migration rates through the diffusive barrier were determined through the application of the one-dimensional, advection/dispersion/diffusion equation. The results showed that because advective flow described by the advection-dispersion equation dominates, the diffusive barrier feature alone would not be effective in retarding migration of radiocuclides. However, if the diffusive barrier were combined with one or more features that reduced the potential for advection, then transport of radionuclides would be dominated by diffusion and their migration from the EBS would be impeded. Apatite was chosen as the getter material used for this report. Two getter configurations were developed, Case 1 and Case 2. As in the evaluation of the diffusive barrier, the effects of advection, hydrodynamic dispersion, and diffusion on the migration of radionuclides through the getter are evaluated. However, in addition to these mechanisms, the one-dimensional advection/dispersion/diffusion model is modified to include the effect of sorption on radionuclide migration rates through the sorptive medium (getter). As a result of sorption, the longitudinal dispersion coefficient, and the average linear velocity are effectively reduced by the retardation factor. The retardation factor is a function of the getter material's dry bulk density, sorption coefficient and moisture content. The results of the evaluation showed that a significant delay in breakthrough through the getter can be achieved if the thickness of the getter barrier is increased.

  1. A Design Method of Code Correlation Reference Waveform in GNSS Based on Least-Squares Fitting.

    PubMed

    Xu, Chengtao; Liu, Zhe; Tang, Xiaomei; Wang, Feixue

    2016-07-29

    The multipath effect is one of the main error sources in the Global Satellite Navigation Systems (GNSSs). The code correlation reference waveform (CCRW) technique is an effective multipath mitigation algorithm for the binary phase shift keying (BPSK) signal. However, it encounters the false lock problem in code tracking, when applied to the binary offset carrier (BOC) signals. A least-squares approximation method of the CCRW design scheme is proposed, utilizing the truncated singular value decomposition method. This algorithm was performed for the BPSK signal, BOC(1,1) signal, BOC(2,1) signal, BOC(6,1) and BOC(7,1) signal. The approximation results of CCRWs were presented. Furthermore, the performances of the approximation results are analyzed in terms of the multipath error envelope and the tracking jitter. The results show that the proposed method can realize coherent and non-coherent CCRW discriminators without false lock points. Generally, there is performance degradation in the tracking jitter, if compared to the CCRW discriminator. However, the performance promotions in the multipath error envelope for the BOC(1,1) and BPSK signals makes the discriminator attractive, and it can be applied to high-order BOC signals.

  2. A Design Method of Code Correlation Reference Waveform in GNSS Based on Least-Squares Fitting

    PubMed Central

    Xu, Chengtao; Liu, Zhe; Tang, Xiaomei; Wang, Feixue

    2016-01-01

    The multipath effect is one of the main error sources in the Global Satellite Navigation Systems (GNSSs). The code correlation reference waveform (CCRW) technique is an effective multipath mitigation algorithm for the binary phase shift keying (BPSK) signal. However, it encounters the false lock problem in code tracking, when applied to the binary offset carrier (BOC) signals. A least-squares approximation method of the CCRW design scheme is proposed, utilizing the truncated singular value decomposition method. This algorithm was performed for the BPSK signal, BOC(1,1) signal, BOC(2,1) signal, BOC(6,1) and BOC(7,1) signal. The approximation results of CCRWs were presented. Furthermore, the performances of the approximation results are analyzed in terms of the multipath error envelope and the tracking jitter. The results show that the proposed method can realize coherent and non-coherent CCRW discriminators without false lock points. Generally, there is performance degradation in the tracking jitter, if compared to the CCRW discriminator. However, the performance promotions in the multipath error envelope for the BOC(1,1) and BPSK signals makes the discriminator attractive, and it can be applied to high-order BOC signals. PMID:27483275

  3. Protein interference with ion-selective electrode measurement depends on reference electrode composition and design.

    PubMed

    Payne, R B; Buckley, B M; Rawson, K M

    1991-01-01

    There is controversy about whether protein interferes with ion measurements using ion-selective electrodes. We have investigated the effects of changes in the salt-bridge composition of five commercially available analysers with open, membrane-restricted or porous frit-restricted reference electrode junctions on measurements of an albumin solution prepared by gel filtration. When the manufacturers' salt bridges were used, instruments with open or membrane-restricted junctions showed apparent increases in the activity of ionized calcium, sodium and potassium in the presence of protein. When the hypertonic bridge solutions were replaced with 150 mmol/L potassium chloride this increase disappeared. The instrument with a porous frit-restricted junction showed no protein effect, but its response to changes in sample sodium chloride concentration in protein-free solution suggested that its junction was functionally equivalent to that formed with an isotonic sodium chloride bridge. Our results emphasize that liquid junction design and composition affect ion measurements in protein-containing solutions and suggest that the use of hypertonic bridge solutions for biological samples needs to be re-examined.

  4. Design of a Model Reference Adaptive Controller for an Unmanned Air Vehicle

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

    2010-01-01

    This paper presents the "Adaptive Control Technology for Safe Flight (ACTS)" architecture, which consists of a non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off nominal ones. The design and implementation procedures of both controllers are presented. The aim of these procedures, which encompass both theoretical and practical considerations, is to develop a controller suitable for flight. The ACTS architecture is applied to the Generic Transport Model developed by NASA-Langley Research Center. The GTM is a dynamically scaled test model of a transport aircraft for which a flight-test article and a high-fidelity simulation are available. The nominal controller at the core of the ACTS architecture has a multivariable LQR-PI structure while the adaptive one has a direct, model reference structure. The main control surfaces as well as the throttles are used as control inputs. The inclusion of the latter alleviates the pilot s workload by eliminating the need for cancelling the pitch coupling generated by changes in thrust. Furthermore, the independent usage of the throttles by the adaptive controller enables their use for attitude control. Advantages and potential drawbacks of adaptation are demonstrated by performing high fidelity simulations of a flight-validated controller and of its adaptive augmentation.

  5. The first lunar outpost: The design reference mission and a new era in lunar science

    NASA Technical Reports Server (NTRS)

    Lofgren, Gary E.

    1993-01-01

    The content of the First Lunar Outpost (FLO) Design Reference Mission has been formulated and a 'strawman' science program has been established. The mission consists of two independent launches using heavy lift vehicles that land directly on the lunar surface. A habitat module and support systems are flown to the Moon first. After confirmation of a successful deployment of the habitat systems, the crewed lunar lander is launched and piloted to within easy walking distance (2 km) of the habitat. By eliminating the Apollo style lunar orbit rendezvous, landing sites at very high latitudes can be considered. A surface rover and the science experiments will accompany the crew. The planned stay time is 45 days, two lunar days and one night. A payload of 3.3 metric tons will support a series of geophysics, geology, astronomy, space physics, resource utilization, and life science experiments. Sample return is 150 to 200 kg. The rover is unpressurized and can carry four astronauts or two astronauts and 500 kg of payload. The rover can also operate in robotic mode with the addition of a robotics package. The science and engineering experiment strategy is built around a representative set of place holder experiments.

  6. Design and characterisation of a thin-film electrode array with shared reference/counter electrodes for electrochemical detection.

    PubMed

    Uludag, Yildiz; Olcer, Zehra; Sagiroglu, Mahmut Samil

    2014-07-15

    In the current study, a novel electrode array and integrated microfluidics have been designed and characterised in order to create a sensor chip which is not only easy, rapid and cheaper to produce but also have a smaller imprint and good electrochemical sensing properties. The current study includes the assessment of the effects of an Au quasi-reference electrode and the use of shared reference/counter electrodes for the array, in order to obtain a small array that can be produced using a fine metal mask. In the study, it is found that when Au is used as the quasi-reference electrode, the arrays with shared reference and counter electrodes result in faster electron transfer kinetics and prevent the potential change with respect to scan rate, and hence is advantageous with respect to conventional electrodes. In addition, the resulting novel electrode array has been shown to result in higher current density (10.52 µA/cm(2); HRP detection assay) and measured diffusion coefficient (14.40×10(-12) cm(2)/s; calculated from the data of cyclic voltammetry with 1mM potassium ferricyanide) with respect to conventional electrodes tested in the study. Using the new electrode arrays, the detection limits obtained from horse radish peroxidase (HRP) and bisphenol A assays were 12.5 ng/ml (2.84×10(-10) M ) and 10 ng/ml (44×10(-9) M), respectively. Performing the HRP detection assay in a flow injection system using array integrated microfluidics provided 25 times lower detection limit (11.36×10(-12) M), although Ti has been used as electrode material instead of Au. In short, incorporation of this new electrode array to lab-on-a-chip or MEMs (micro-electro mechanic systems) technologies may pave the way for easy to use automated biosensing devices that could be used for a variety of applications from diagnostics to environmental monitoring, and studies will continue to move forward in this direction.

  7. Plasma motor/generator reference system designs for power and propulsion

    NASA Technical Reports Server (NTRS)

    Mccoy, James E.

    1987-01-01

    Four Plasma Motor/Generator (PMG) Reference Systems, hollow cathode-based versions of the electrodynamic tether concept which are to be used in study and analysis of future propulsion and power applications, are discussed. These systems are equally applicable for use as electric generators to provide power to a spacecraft or as electric motors using power from the spacecraft. Operating at relatively high current and low voltage, the PMGs avoid requirements for technological advances to handle very high voltages. Permanent deployment with passive I x B control of tether dynamics eliminates the complexity and weight of a TSS style tether reel. A 20 kW PMG uses 10 km of number two aluminum wire, weighs 1200 kg, and has an electrical efficiency of 93 percent. A larger 200 kW system uses 20 km of number 00 aluminum wire, weighs 4200 kg, and operates at 87 percent efficiency.

  8. Instructional Designers at Work: A Study of How Designers Design

    ERIC Educational Resources Information Center

    Dicks, Dennis; Ives, Cindy

    2008-01-01

    Instructional design (ID) in its short life has been dominated by behaviourist approaches despite critique focusing on issues of practice as well as theory. Nonetheless, little research has addressed two fundamental questions: "What constitutes good instructional design?" and "How do instructional designers create good design?"…

  9. Adjoint-Based Design of Rotors using the Navier-Stokes Equations in a Noninertial Reference Frame

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Lee-Rausch, Elizabeth M.; Jones, William T.

    2009-01-01

    Optimization of rotorcraft flowfields using an adjoint method generally requires a time-dependent implementation of the equations. The current study examines an intermediate approach in which a subset of rotor flowfields are cast as steady problems in a noninertial reference frame. This technique permits the use of an existing steady-state adjoint formulation with minor modifications to perform sensitivity analyses. The formulation is valid for isolated rigid rotors in hover or where the freestream velocity is aligned with the axis of rotation. Discrete consistency of the implementation is demonstrated using comparisons with a complex-variable technique, and a number of single- and multi-point optimizations for the rotorcraft figure of merit function are shown for varying blade collective angles. Design trends are shown to remain consistent as the grid is refined.

  10. Adjoint-Based Design of Rotors Using the Navier-Stokes Equations in a Noninertial Reference Frame

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Lee-Rausch, Elizabeth M.; Jones, William T.

    2010-01-01

    Optimization of rotorcraft flowfields using an adjoint method generally requires a time-dependent implementation of the equations. The current study examines an intermediate approach in which a subset of rotor flowfields are cast as steady problems in a noninertial reference frame. This technique permits the use of an existing steady-state adjoint formulation with minor modifications to perform sensitivity analyses. The formulation is valid for isolated rigid rotors in hover or where the freestream velocity is aligned with the axis of rotation. Discrete consistency of the implementation is demonstrated by using comparisons with a complex-variable technique, and a number of single- and multipoint optimizations for the rotorcraft figure of merit function are shown for varying blade collective angles. Design trends are shown to remain consistent as the grid is refined.

  11. Visual Design Principles: An Empirical Study of Design Lore

    ERIC Educational Resources Information Center

    Kimball, Miles A.

    2013-01-01

    Many books, designers, and design educators talk about visual design principles such as balance, contrast, and alignment, but with little consistency. This study uses empirical methods to explore the lore surrounding design principles. The study took the form of two stages: a quantitative literature review to determine what design principles are…

  12. Weather parameters and nosocomial bloodstream infection: a case-referent study

    PubMed Central

    Caldeira, Silvia Maria; da Cunha, Antonio Ribeiro; Akazawa, Renata Tamie; Moreira, Rayana Gonçalves; de Souza, Lenice do Rosário; Fortaleza, Carlos Magno Castelo Branco

    2015-01-01

    OBJECTIVE To evaluate if temperature and humidity influenced the etiology of bloodstream infections in a hospital from 2005 to 2010. METHODS The study had a case-referent design. Individual cases of bloodstream infections caused by specific groups or pathogens were compared with several references. In the first analysis, average temperature and humidity values for the seven days preceding collection of blood cultures were compared with an overall “seven-days moving average” for the study period. The second analysis included only patients with bloodstream infections. Several logistic regression models were used to compare different pathogens and groups with respect to the immediate weather parameters, adjusting for demographics, time, and unit of admission. RESULTS Higher temperatures and humidity were related to the recovery of bacteria as a whole (versus fungi) and of gram-negative bacilli. In the multivariable models, temperature was positively associated with the recovery of gram-negative bacilli (OR = 1.14; 95%CI 1.10;1.19) or Acinetobacter baumannii (OR = 1.26; 95%CI 1.16;1.37), even after adjustment for demographic and admission data. An inverse association was identified for humidity. CONCLUSIONS The study documented the impact of temperature and humidity on the incidence and etiology of bloodstream infections. The results correspond with those from ecological studies, indicating a higher incidence of gram-negative bacilli during warm seasons. These findings should guide policies directed at preventing and controlling healthcare-associated infections. PMID:25830871

  13. Towards a reference cavitating vessel Part III—design and acoustic pressure characterization of a multi-frequency sonoreactor

    NASA Astrophysics Data System (ADS)

    Wang, Lian; Memoli, Gianluca; Hodnett, Mark; Butterworth, Ian; Sarno, Dan; Zeqiri, Bajram

    2015-08-01

    A multi-frequency cavitation vessel (RV-multi) has been commissioned at the National Physical Laboratory (NPL, UK), with the aim of establishing a standard source of acoustic cavitation in water, with reference to which details of the cavitation process can be studied and cavitation measurement techniques evaluated. The vessel is a cylindrical cavity with a maximum capacity up to 17 L, and is designed to work at six frequency ranges, from 21 kHz to 136 kHz, under controlled temperature conditions. This paper discusses the design of RV-multi and reports experiments carried out to establish the reproducibility of the acoustic pressure field established within the vessel and its operating envelope, including sensitivity to aspects such as water depth and temperature. The acoustic field distribution was determined along the radial and depth directions within the vessel using a miniature hydrophone, for two input voltage levels under low power transducer excitation conditions (e.g. below the cavitation threshold). Particular care was taken in determining peak acoustic pressure locations, as these are critical for accompanying cavitation studies. Perturbations of the vessel by the measuring hydrophone were also monitored with a bottom-mounted pressure sensor.

  14. Using DOE Commercial Reference Buildings for Simulation Studies: Preprint

    SciTech Connect

    Field, K.; Deru, M.; Studer, D.

    2010-08-01

    The U.S. Department of Energy developed 256 EnergyPlus models for use in studies that aim to characterize about 70% of the U.S. commercial building stock. Sixteen building types - including restaurants, health care, schools, offices, supermarkets, retail, lodging, and warehouses - are modeled across 16 cities to represent the diversity of U.S. climate zones. Weighting factors have been developed to combine the models in proportions similar to those of the McGraw-Hill Construction Projects Starts Database for 2003-2007. This paper reviews the development and contents of these models and their applications in simulation studies.

  15. Advanced turbine systems: Studies and conceptual design

    SciTech Connect

    van der Linden, S.; Gnaedig, G.; Kreitmeier, F.

    1993-11-01

    The ABB selection for the Advanced Turbine System (ATS) includes advanced developments especially in the hot gas path of the combustion turbine and new state-of-the-art units such as the steam turbine and the HRSG. The increase in efficiency by more than 10% multiplicative compared to current designs will be based on: (1) Turbine Inlet Temperature Increase; (2) New Cooling Techniques for Stationary and Rotating Parts; and New Materials. Present, projected component improvements that will be introduced with the above mentioned issues will yield improved CCSC turbine performance, which will drive the ATS selected gas-fired reference CC power plant to 6 % LHV or better. The decrease in emission levels requires a careful optimization of the cycle design, where cooling air consumption has to be minimized. All interfaces of the individual systems in the complete CC Plant need careful checks, especially to avoid unnecessary margins in the individual designs. This study is an important step pointing out the feasibility of the ATS program with realistic goals set by DOE, which, however, will present challenges for Phase II time schedule of 18 months. With the approach outlined in this study and close cooperation with DOE, ATS program success can be achieved to deliver low emissions and low cost of electricity by the year 2002. The ABB conceptual design and step approach will lead to early component demonstration which will help accelerate the overall program objectives.

  16. A Phobos-Deimos Mission as an Element of the NASA Mars Design Reference Architecture 5.0

    NASA Technical Reports Server (NTRS)

    Hoffman, Stephen J.

    2011-01-01

    NASA has conducted a series of mission studies over the past 25 years examining the eventual exploration of the surface of Mars by humans. The latest version of this evolutionary series of design reference missions/architectures - Design Reference Architecture 5 or DRA-5 - was completed in 2007. This paper examines the implications of including a human mission to explore the moons of Mars and teleoperate robots in various locations, but not to land the human crews on Mars, as an element of this reference architecture. Such a mission has been proposed several times during this same 25 year evolution leading up to the completion of DRA-5 primarily as a mission of testing the in-space vehicles and operations while surface vehicles and landers are under development. But such a precursor or test mission has never been explicitly included as an element of this Architecture. This paper will first summarize the key features of the DRA-5 to provide context for the remainder of the assessment. This will include a description of the in-space vehicles that would be the subject of a shakedown test during the Mars orbital mission. A decision tree will be used to illustrate the factors that will be analyzed, and the sequence in which they will be addressed, for this assessment. The factors that will be analyzed include the type of interplanetary transfer orbit (opposition class versus conjunction class), the type of parking orbit (circular versus elliptical), and the type of propulsion technology (high thrust chemical versus nuclear thermal rocket). The manner in which each of these factors impacts an individual mission will be described. In addition to the direct impact of these factors, additional considerations impacting crew health and overall programmatic outcomes will be discussed. Numerical results for each of the factors in the decision tree will be grouped with derived qualitative impacts from crew health and programmatic consideration. These quantitative and qualitative

  17. National accounts manager: Design study. Final report

    SciTech Connect

    Waggoner, J.

    1998-09-01

    This document addresses a typical application -- that of a hypothetical nationwide chain of restaurants. The design study uses the Reference Model for Open Distributed Processing (RM-ODP) as a guideline for specifying standard systems. Far from limiting the study`s usefulness to a particular type of National Account, this guideline is highly portable, and will be useful, with slight modifications only, in similarly specifying systems for other types of customers. A brief list of other applications could include many ``campus`` environments -- government agencies and university systems as well as manufacturers, airports, railyards, ski resorts, apartment complexes, hotels, hospitals, telecommunication facilities, oil fields, irrigation systems, municipal water/sewer systems, and so on.

  18. The development of risk assessment models for carpal tunnel syndrome: a case-referent study.

    PubMed

    You, Heecheon; Simmons, Zachary; Freivalds, Andris; Kothari, Milind; Naidu, Sanjiv; Young, Ronda

    2004-05-15

    The present study developed risk assessment models for carpal tunnel syndrome (CTS) which can provide information of the likelihood of developing CTS for an individual having certain personal characteristics and occupational risks. A case-referent study was conducted consisting of two case groups and one referent group: (1) 22 work-related CTS patients (W-CTS), (2) 25 non-work related CTS patients (NW-CTS), and (3) 50 healthy workers (HEALTHY) having had no CTS history. The classification of CTS patients into one of the case groups was determined according to the type of insurance covering their medical costs. Personal characteristics, psychosocial stresses at work, and physical work conditions were surveyed by using a questionnaire tailor-designed to CTS (reliability of each scale > or = 0.7). By contrasting the risk information of each case group to that of the referent group, three logistic regression models were developed: W-CTS/HEALTHY, NW-CTS/HEALTHY, and C-CTS/HEALTHY (C-CTS, the combined group of W-CTS and NW-CTS). ROC analysis indicated that the models have satisfactory discriminability (d' = 1.91 to 2.51) and high classification accuracy (overall accuracy = 83-89%). Both W-CTS/HEALTHY and C-CTS/HEALTHY include personal and physical factors, while NW-CTS/HEALTHY involves only personal factors. This suggests that the injury causation of NW-CTS patients should be attributable mainly to their 'high' personal susceptibility to the disorder rather than exposure to adverse work conditions, while that of W-CTS patients be attributable to improper work conditions and CTS-prone personal characteristics in combination.

  19. Liquid belt radiator design study

    NASA Technical Reports Server (NTRS)

    Teagan, W. P.; Fitzgerald, K. F.

    1986-01-01

    The Liquid Belt Radiator (LBR) is an advanced concept developed to meet the needs of anticipated future space missions. A previous study documented the advantages of this concept as a lightweight, easily deployable alternative to present day space heat rejection systems. The technical efforts associated with this study concentrate on refining the concept of the LBR as well as examining the issues of belt dynamics and potential application of the LBR to intermediate and high temperature heat rejection applications. A low temperature point design developed in previous work is updated assuming the use of diffusion pump oil, Santovac-6, as the heat transfer media. Additional analytical and design effort is directed toward determining the impact of interface heat exchanger, fluid bath sealing, and belt drive mechanism designs on system performance and mass. The updated design supports the earlier result by indicating a significant reduction in system specific system mass as compared to heat pipe or pumped fluid radiator concepts currently under consideration (1.3 kg/sq m versus 5 kg/sq m).

  20. Heat source reentry vehicle design study

    NASA Technical Reports Server (NTRS)

    Ryan, R. L.

    1971-01-01

    The design details are presented of a flight-type heat source reentry vehicle and heat exchanger compatible with the isotope Brayton power conversion system. The reference reentry vehicle and heat exchanger were modified, orbital and superorbital capability was assessed, and a complete set of detail design layout drawings were provided.

  1. STUDY CARRELS, DESIGNS FOR INDEPENDENT STUDY SPACE.

    ERIC Educational Resources Information Center

    BEYNON, JOHN

    BECAUSE OF THE DEMAND FOR INDIVIDUALIZED INSTRUCTION, NEW SCHOOLS ARE BEING PLANNED WITH LESS CLASSROOM SPACE AND MORE LIBRARY AND INDIVIDUAL STUDY SPACES. THESE NEW SCHOOLS REQUIRE NEW KINDS OF FURNITURE DESIGNED PRIMARILY TO GIVE THE STUDENT A DEGREE OF PRIVACY RATHER THAN TO PROVIDE OPTIMUM CONTROL TO TEACHERS. THE CARREL, PREVIOUSLY USED…

  2. Design and implementation of magnetically maneuverable capsule endoscope system with direction reference for image navigation.

    PubMed

    Sun, Zhen-Jun; Ye, Bo; Sun, Yi; Zhang, Hong-Hai; Liu, Sheng

    2014-07-01

    This article describes a novel magnetically maneuverable capsule endoscope system with direction reference for image navigation. This direction reference was employed by utilizing a specific magnet configuration between a pair of external permanent magnets and a magnetic shell coated on the external capsule endoscope surface. A pair of customized Cartesian robots, each with only 4 degrees of freedom, was built to hold the external permanent magnets as their end-effectors. These robots, together with their external permanent magnets, were placed on two opposite sides of a "patient bed." Because of the optimized configuration based on magnetic analysis between the external permanent magnets and the magnetic shell, a simplified control strategy was proposed, and only two parameters, yaw step angle and moving step, were necessary for the employed robotic system. Step-by-step experiments demonstrated that the proposed system is capable of magnetically maneuvering the capsule endoscope while providing direction reference for image navigation.

  3. H2FIRST Reference Station Design Task: Project Deliverable 2-2

    SciTech Connect

    Pratt, Joseph; Terlip, Danny; Ainscough, Chris; Kurtz, Jennifer; Elgowainy, Amgad

    2015-04-20

    This report presents near-term station cost results and discusses cost trends of different station types. It compares various vehicle rollout scenarios and projects realistic near-term station utilization values using the station infrastructure rollout in California as an example. It describes near-term market demands and matches those to cost-effective station concepts. Finally, the report contains detailed designs for five selected stations, which include piping and instrumentation diagrams, bills of materials, and several site-specific layout studies that incorporate the setbacks required by NFPA 2, the National Fire Protection Association Hydrogen Technologies Code. This work identified those setbacks as a significant factor affecting the ability to site a hydrogen station, particularly liquid stations at existing gasoline stations. For all station types, utilization has a large influence on the financial viability of the station.

  4. Design and assembly sequence analysis of option 3 for CETF reference space station

    NASA Technical Reports Server (NTRS)

    Garrett, L. Bernard; Andersen, Gregory C.; Hall, John B., Jr.; Allen, Cheryl L.; Scott, A. D., Jr.; So, Kenneth T.

    1987-01-01

    A design and assembly sequence was conducted on one option of the Dual Keel Space Station examined by a NASA Critical Evaluation Task Force to establish viability of several variations of that option. A goal of the study was to produce and analyze technical data to support Task Force decisions to either examine particular Option 3 variations in more depth or eliminate them from further consideration. An analysis of the phasing assembly showed that use of an Expendable Launch Vehicle in conjunction with the Space Transportation System (STS) can accelerate the buildup of the Station and ease the STS launch rate constraints. The study also showed that use of an Orbital Maneuvering Vehicle on the first flight can significantly benefit Station assembly and, by performing Station subsystem functions, can alleviate the need for operational control and reboost systems during the early flights. In addition to launch and assembly sequencing, the study assessed stability and control, and analyzed node-packaging options and the effects of keel removal on the structural dynamics of the Station. Results of these analyses are presented and discussed.

  5. Warm gas TVC design study

    NASA Technical Reports Server (NTRS)

    Moorhead, S. B., Jr.

    1973-01-01

    A warm gas thrust vector control system was studied to optimize the injection geometry for a specific engine configuration, and an injection valve was designed capable of meeting the base line requirements. To optimize injection geometry, studies were made to determine the performance effects of varying injection location, angle, port size, and port configuration. Having minimized the injection flow rate required, a warm gas valve was designed to handle the required flow. A direct drive hydraulic servovalve capable of operating with highly contaminated hydraulic fluid was designed. The valve is sized to flow 15 gpm at 3000 psia and the direct drive feature is capable of applying a spool force of 200 pounds. The baseline requirements are the development of 6 deg of thrust vector control utilizing 2000 F (total temperature) gas for 180 seconds on a 1.37 million pound thrust engine burning LOX and RP-1 at a chamber pressure of 250 psia with a 155 inch long conical nozzle having a 68 inch diameter throat and a 153 inch diameter exit.

  6. Design implementation and control of MRAS error dynamics. [Model-Reference Adaptive System

    NASA Technical Reports Server (NTRS)

    Colburn, B. K.; Boland, J. S., III

    1974-01-01

    Use is made of linearized error characteristic equation for model-reference adaptive systems to determine a parameter adjustment rule for obtaining time-invariant error dynamics. Theoretical justification of error stability is given and an illustrative example included to demonstrate the utility of the proposed technique.

  7. Validation of reference genes for gene expression studies in soybean aphid, Aphis glycines Matsumura

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative real-time PCR (qRT-PCR) is a common tool for quantifying mRNA transcripts. To normalize results, a reference gene is mandatory. Aphis glycines is a significant soybean pest, yet gene expression and functional genomics studies are hindered by a lack of stable reference genes. We evalu...

  8. Digital Reference: A Case Study of Question Types in an Academic Library.

    ERIC Educational Resources Information Center

    Diamond, Wendy; Pease, Barbara

    2001-01-01

    Describes a study at California State University at Chico that analyzed the types of reference questions received by their digital reference service over a two-year period. Suggests a strategy for improving the process of answering broad or complex questions remotely. (Author/LRW)

  9. Essentials of College and University Accounting: A Reference Companion to NACUBO's Online Self-Study Course

    ERIC Educational Resources Information Center

    National Association of College and University Business Officers (NJ3), 2006

    2006-01-01

    This reference guide presents the basic accounting concepts, terminology, and definitions used by colleges and universities. The guide, a companion to the National Association of College and University Business Officers' (NACUBO's) online self-study course of the same name or a standalone reference, compares college and university accounting…

  10. Development and Evaluation of Reference Standards for Image-based Telemedicine Diagnosis and Clinical Research Studies in Ophthalmology

    PubMed Central

    Ryan, Michael C.; Ostmo, Susan; Jonas, Karyn; Berrocal, Audina; Drenser, Kimberly; Horowitz, Jason; Lee, Thomas C.; Simmons, Charles; Martinez-Castellanos, Maria-Ana; Chan, R.V. Paul; Chiang, Michael F.

    2014-01-01

    Information systems managing image-based data for telemedicine or clinical research applications require a reference standard representing the correct diagnosis. Accurate reference standards are difficult to establish because of imperfect agreement among physicians, and discrepancies between clinical vs. image-based diagnosis. This study is designed to describe the development and evaluation of reference standards for image-based diagnosis, which combine diagnostic impressions of multiple image readers with the actual clinical diagnoses. We show that agreement between image reading and clinical examinations was imperfect (689 [32%] discrepancies in 2148 image readings), as was inter-reader agreement (kappa 0.490-0.652). This was improved by establishing an image-based reference standard defined as the majority diagnosis given by three readers (13% discrepancies with image readers). It was further improved by establishing an overall reference standard that incorporated the clinical diagnosis (10% discrepancies with image readers). These principles of establishing reference standards may be applied to improve robustness of real-world systems supporting image-based diagnosis. PMID:25954463

  11. Development and Evaluation of Reference Standards for Image-based Telemedicine Diagnosis and Clinical Research Studies in Ophthalmology.

    PubMed

    Ryan, Michael C; Ostmo, Susan; Jonas, Karyn; Berrocal, Audina; Drenser, Kimberly; Horowitz, Jason; Lee, Thomas C; Simmons, Charles; Martinez-Castellanos, Maria-Ana; Chan, R V Paul; Chiang, Michael F

    2014-01-01

    Information systems managing image-based data for telemedicine or clinical research applications require a reference standard representing the correct diagnosis. Accurate reference standards are difficult to establish because of imperfect agreement among physicians, and discrepancies between clinical vs. image-based diagnosis. This study is designed to describe the development and evaluation of reference standards for image-based diagnosis, which combine diagnostic impressions of multiple image readers with the actual clinical diagnoses. We show that agreement between image reading and clinical examinations was imperfect (689 [32%] discrepancies in 2148 image readings), as was inter-reader agreement (kappa 0.490-0.652). This was improved by establishing an image-based reference standard defined as the majority diagnosis given by three readers (13% discrepancies with image readers). It was further improved by establishing an overall reference standard that incorporated the clinical diagnosis (10% discrepancies with image readers). These principles of establishing reference standards may be applied to improve robustness of real-world systems supporting image-based diagnosis.

  12. Design Evolution Study - Aging Options

    SciTech Connect

    P. McDaniel

    2002-04-05

    The purpose of this study is to identify options and issues for aging commercial spent nuclear fuel received for disposal at the Yucca Mountain Mined Geologic Repository. Some early shipments of commercial spent nuclear fuel to the repository may be received with high-heat-output (younger) fuel assemblies that will need to be managed to meet thermal goals for emplacement. The capability to age as much as 40,000 metric tons of heavy metal of commercial spent nuclear he1 would provide more flexibility in the design to manage this younger fuel and to decouple waste receipt and waste emplacement. The following potential aging location options are evaluated: (1) Surface aging at four locations near the North Portal; (2) Subsurface aging in the permanent emplacement drifts; and (3) Subsurface aging in a new subsurface area. The following aging container options are evaluated: (1) Complete Waste Package; (2) Stainless Steel inner liner of the waste package; (3) Dual Purpose Canisters; (4) Multi-Purpose Canisters; and (5) New disposable canister for uncanistered commercial spent nuclear fuel. Each option is compared to a ''Base Case,'' which is the expected normal waste packaging process without aging. A Value Engineering approach is used to score each option against nine technical criteria and rank the options. Open issues with each of the options and suggested future actions are also presented. Costs for aging containers and aging locations are evaluated separately. Capital costs are developed for direct costs and distributable field costs. To the extent practical, unit costs are presented. Indirect costs, operating costs, and total system life cycle costs will be evaluated outside of this study. Three recommendations for aging commercial spent nuclear fuel--subsurface, surface, and combined surface and subsurface are presented for further review in the overall design re-evaluation effort. Options that were evaluated but not recommended are: subsurface aging in a new

  13. Mars Global Reference Atmospheric Model (Mars-GRAM) and Database for Mission Design

    NASA Technical Reports Server (NTRS)

    Justus, C. G.; Duvall, Aleta; Johnson, D. L.

    2003-01-01

    Mars Global Reference Atmospheric Model (Mars-GRAM 2001) is an engineering-level Mars atmosphere model widely used for many Mars mission applications. From 0-80 km, it is based on NASA Ames Mars General Circulation Model, while above 80 km it is based on Mars Thermospheric General Circulation Model. Mars-GRAM 2001 and MGCM use surface topography from Mars Global Surveyor Mars Orbiting Laser Altimeter. Validation studies are described comparing Mars-GRAM with Mars Global Surveyor Radio Science and Thermal Emission Spectrometer data. RS data from 2480 profiles were used, covering latitudes 75 deg S to 72 deg N, surface to approximately 40 km, for seasons ranging from areocentric longitude of Sun (Ls) = 70-160 deg and 265-310 deg. RS data spanned a range of local times, mostly 0-9 hours and 18-24 hours. For interests in aerocapture and precision landing, comparisons concentrated on atmospheric density. At a fixed height of 20 km, RS density varied by about a factor of 2.5 over ranges of latitudes and Ls values observed. Evaluated at matching positions and times, these figures show average RSMars-GRAM density ratios were generally 1+/-)0.05, except at heights above approximately 25 km and latitudes above approximately 50 deg N. Average standard deviation of RSMars-GRAM density ratio was 6%. TES data were used covering surface to approximately 40 km, over more than a full Mars year (February, 1999 - June, 2001, just before start of a Mars global dust storm). Depending on season, TES data covered latitudes 85 deg S to 85 deg N. Most TES data were concentrated near local times 2 hours and 14 hours. Observed average TES/Mars-GRAM density ratios were generally 1+/-0.05, except at high altitudes (15-30 km, depending on season) and high latitudes (greater than 45 deg N), or at most altitudes in the southern hemisphere at Ls approximately 90 and 180 deg. Compared to TES averages for a given latitude and season, TES data had average density standard deviation about the mean of

  14. The proton driver design study

    SciTech Connect

    Editors: W. Chou, C.M. Ankenbrandt and E.I. Malamud

    2001-03-08

    In a 1997 summer study, a team led by Steve Holmes formulated a development plan for the Fermilab proton source and described the results in TM-2021. Subsequently, at the end of 1998, a task group was formed to prepare a detailed design of a high intensity facility called the Proton Driver to replace the Fermilab Booster. In the past two years the design effort has attracted more than fifty participants, mostly from the Beams Division. Physicists and engineers from the Technical Division and FESS as well as other institutions, including the Illinois Institute of Technology (IIT), Stanford University, University of Hawaii, CERN in Switzerland, Rutherford Appleton Laboratory in England and the IHEP in Russia also contributed heavily. The results of that effort are summarized in this document describing the design of a 16 GeV synchrotron, two new beam transport lines (a 400 MeV injection line and a 12/16 GeV extraction line), and related improvements to the present negative ion source and the 400 MeV Linac. A construction cost estimate is presented in Appendix A.

  15. Design Issues in Transgender Studies

    PubMed Central

    Emel, Lynda; Hanscom, Brett; Zangeneh, Sahar

    2016-01-01

    Abstract: Transgender individuals constitute an important focus for HIV prevention, but studies in this population present some unique methodologic and operational challenges. We consider issues related to sampling, sample size, number of sites, and trial cost. We discuss relevant design issues for evaluating interventions in both HIV-negative and HIV-infected transgender populations, as well as a method for assessing the impact of an intervention on population HIV incidence. We find that HIV-endpoint studies of transgender individuals will likely require fewer participants but more sites and have higher operational costs than HIV prevention trials in other populations. Because any intervention targeted to transgender individuals will likely include antiretroviral drugs, small scale studies looking at potential interactions between antiretroviral therapy and hormone therapy are recommended. Finally, assessing the impact of an intervention targeted to transgender individuals will require better information on the contribution of such individuals to the population HIV incidence. PMID:27429191

  16. Radioactive waste isolation in salt: peer review of Westinghouse Electric Corporation's report on reference conceptual designs for a repository waste package

    SciTech Connect

    Rote, D.M.; Hull, A.B.; Was, G.S.; Macdonald, D.D.; Wilde, B.E.; Russell, J.E.; Kruger, J.; Harrison, W.; Hambley, D.F.

    1985-10-01

    This report documents the findings of the peer panel constituted by Argonne National Laboratory to review Region A of Westinghouse Electric Corporation's report entitled Waste Package Reference Conceptual Designs for a Repository in Salt. The panel determined that the reviewed report does not provide reasonable assurance that US Nuclear Regulatory Commission (NRC) requirements for waste packages will be met by the proposed design. It also found that it is premature to call the design a ''reference design,'' or even a ''reference conceptual design.'' This review report provides guidance for the preparation of a more acceptable design document.

  17. Optimal adaptive sequential designs for crossover bioequivalence studies.

    PubMed

    Xu, Jialin; Audet, Charles; DiLiberti, Charles E; Hauck, Walter W; Montague, Timothy H; Parr, Alan F; Potvin, Diane; Schuirmann, Donald J

    2016-01-01

    In prior works, this group demonstrated the feasibility of valid adaptive sequential designs for crossover bioequivalence studies. In this paper, we extend the prior work to optimize adaptive sequential designs over a range of geometric mean test/reference ratios (GMRs) of 70-143% within each of two ranges of intra-subject coefficient of variation (10-30% and 30-55%). These designs also introduce a futility decision for stopping the study after the first stage if there is sufficiently low likelihood of meeting bioequivalence criteria if the second stage were completed, as well as an upper limit on total study size. The optimized designs exhibited substantially improved performance characteristics over our previous adaptive sequential designs. Even though the optimized designs avoided undue inflation of type I error and maintained power at ≥ 80%, their average sample sizes were similar to or less than those of conventional single stage designs.

  18. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    SciTech Connect

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  19. Determination of reference genes for circadian studies in different tissues and mouse strains

    PubMed Central

    2010-01-01

    Background Circadian rhythms have a profound effect on human health. Their disruption can lead to serious pathologies, such as cancer and obesity. Gene expression studies in these pathologies are often studied in different mouse strains by quantitative real time polymerase chain reaction (qPCR). Selection of reference genes is a crucial step of qPCR experiments. Recent studies show that reference gene stability can vary between species and tissues, but none has taken circadian experiments into consideration. Results In the present study the expression of ten candidate reference genes (Actb, Eif2a, Gapdh, Hmbs, Hprt1, Ppib, Rn18s, Rplp0, Tbcc and Utp6c) was measured in 131 liver and 97 adrenal gland samples taken from three mouse strains (C57BL/6JOlaHsd, 129Pas plus C57BL/6J and Crem KO on 129Pas plus C57BL/6J background) every 4 h in a 24 h period. Expression stability was evaluated by geNorm and NormFinder programs. Differences in ranking of the most stable reference genes were observed both between individual mouse strains as well as between tissues within each mouse strain. We show that selection of reference gene (Actb) that is often used for analyses in individual mouse strains leads to errors if used for normalization when different mouse strains are compared. We identified alternative reference genes that are stable in these comparisons. Conclusions Genetic background and circadian time influence the expression stability of reference genes. Differences between mouse strains and tissues should be taken into consideration to avoid false interpretations. We show that the use of a single reference gene can lead to false biological conclusions. This manuscript provides a useful reference point for researchers that search for stable reference genes in the field of circadian biology. PMID:20712867

  20. Power Requirements for The NASA Mars Design Reference Architecture (DRA) 5.0

    NASA Technical Reports Server (NTRS)

    Cataldo, Robert L.

    2009-01-01

    This paper summarizes the power systems analysis results from NASA s recent Mars DRA 5.0 study which examined three architecture options and resulting mission requirements for a human Mars landing mission in the post-2030 timeframe. DRA 5.0 features a long approximately 500 day surface stay split mission using separate cargo and crewed Mars transfer vehicles. Two cargo flights, utilizing minimum energy trajectories, pre-deploy a cargo lander to the surface and a habitat lander into a 24-hour elliptical Mars parking orbit where it remains until the arrival of the crew during the next mission opportunity approximately 26 months later. The pre-deployment of cargo poses unique challenges for set-up and emplacement of surface assets that results in the need for self or robotically deployed designs. Three surface architecture options were evaluated for breadth of science content, extent of exploration range/capability and variations in system concepts and technology. This paper describes the power requirements for the surface operations of the three mission options, power system analyses including discussion of the nuclear fission, solar photovoltaic and radioisotope concepts for main base power and long range mobility.

  1. Design and realization of the high-precision weighing systems as the gravimetric references in PTB's national water flow standard

    NASA Astrophysics Data System (ADS)

    Engel, Rainer; Beyer, Karlheinz; Baade, Hans-Joachim

    2012-07-01

    PTB's ‘Hydrodynamic Test Field’, which represents a high-accuracy water flow calibration facility, serves as the national primary standard for liquid flow measurands. As the core reference device of this flow facility, a gravimetric standard has been incorporated, which comprises three special-design weighing systems: 300 kg, 3 tons and 30 tons. These gravimetric references were realized as a combination of a strain-gauge-based and an electromagnetic-force-compensation load-cell-based balance, each. Special emphasis had to be placed upon the dynamics design of the whole weighing system, due to the high measurement resolution and the dynamic behavior of the weighing systems, which are dynamically affected by mechanical vibrations caused by environmental impacts, flow machinery operation, flow noise in the pipework and induced wave motions in the weigh tanks. Taking into account all the above boundary conditions, the design work for the gravimetric reference resulted in a concrete foundation ‘rock’ of some 300 tons that rests on a number of vibration isolators. In addition to these passively operating vibration isolators, the vibration damping effect is enhanced by applying an electronic level regulation device.

  2. MIUS community conceptual design study

    NASA Technical Reports Server (NTRS)

    Fulbright, B. E.

    1976-01-01

    The feasibility, practicality, and applicability of the modular integrated utility systems (MIUS) concept to a satellite new-community development with a population of approximately 100,000 were analyzed. Two MIUS design options, the 29-MIUS-unit (option 1) and the 8-MIUS-unit (option 2) facilities were considered. Each resulted in considerable resource savings when compared to a conventional utility system. Economic analyses indicated that the total cash outlay and operations and maintenance costs for these two options were considerably less than for a conventional system. Computer analyses performed in support of this study provided corroborative data for the study group. An environmental impact assessment was performed to determine whether the MIUS meets or will meet necessary environmental standards. The MIUS can provide improved efficiency in the conservation of natural resources while not adversely affecting the physical environment.

  3. Multiple myeloma and engine exhausts, fresh wood, and creosote: a case-referent study

    SciTech Connect

    Flodin, U.; Fredriksson, M.; Persson, B.

    1987-01-01

    The effect of potential risk factors for multiple myeloma was evaluated in a case-referent study encompassing 131 cases and 431 randomized referents, all alive. Information on exposure was obtained with questionnaires mailed to the subjects. An analysis of the material by means of the Miettinen confounder score technique resulted in a few rate ratios significantly exceeding unity--namely, occupational exposure to engine exhausts, creosote, and fresh wood. In view of other studies that suggest ionizing radiation as a risk factor, it was somewhat surprising that low-level gamma radiation from background exposure was less common among the cases than the referents.

  4. Multiple myeloma and engine exhausts, fresh wood, and creosote: a case-referent study.

    PubMed

    Flodin, U; Fredriksson, M; Persson, B

    1987-01-01

    The effect of potential risk factors for multiple myeloma was evaluated in a case-referent study encompassing 131 cases and 431 randomized referents, all alive. Information on exposure was obtained with questionnaires mailed to the subjects. An analysis of the material by means of the Miettinen confounder score technique resulted in a few rate ratios significantly exceeding unity--namely, occupational exposure to engine exhausts, creosote, and fresh wood. In view of other studies that suggest ionizing radiation as a risk factor, it was somewhat surprising that low-level gamma radiation from background exposure was less common among the cases than the referents.

  5. SP-100 system definition conceptual reference design activities: February through June 1983. Technical information report

    SciTech Connect

    Fortenberry, J.W.; Moore, D.M.; Petrick, S.W.; Smoak, R.H.

    1983-12-01

    The original SP-100 conceptual system design was examined from the mechanical design and integration viewpoint for the purpose of updating the design, identifying concerns, and providing recommendations for future work. Some of the findings were that: Integration of heat pipes into the radiator structure appears practical, but a number of problems remain to be addressed and resolved through development effort; thermal and structural interfacing of the shield and defining shield weight are key areas that need to be addressed; the radiator may be critical in shell buckling which would make beryllium a leading candidate material; material problems such as beryllium vs. shuttle fracture mechanics criteria need to be addressed.

  6. Gain-Scheduled Complementary Filter Design for a MEMS Based Attitude and Heading Reference System

    PubMed Central

    Yoo, Tae Suk; Hong, Sung Kyung; Yoon, Hyok Min; Park, Sungsu

    2011-01-01

    This paper describes a robust and simple algorithm for an attitude and heading reference system (AHRS) based on low-cost MEMS inertial and magnetic sensors. The proposed approach relies on a gain-scheduled complementary filter, augmented by an acceleration-based switching architecture to yield robust performance, even when the vehicle is subject to strong accelerations. Experimental results are provided for a road captive test during which the vehicle dynamics are in high-acceleration mode and the performance of the proposed filter is evaluated against the output from a conventional linear complementary filter. PMID:22163824

  7. Gain-scheduled complementary filter design for a MEMS based attitude and heading reference system.

    PubMed

    Yoo, Tae Suk; Hong, Sung Kyung; Yoon, Hyok Min; Park, Sungsu

    2011-01-01

    This paper describes a robust and simple algorithm for an attitude and heading reference system (AHRS) based on low-cost MEMS inertial and magnetic sensors. The proposed approach relies on a gain-scheduled complementary filter, augmented by an acceleration-based switching architecture to yield robust performance, even when the vehicle is subject to strong accelerations. Experimental results are provided for a road captive test during which the vehicle dynamics are in high-acceleration mode and the performance of the proposed filter is evaluated against the output from a conventional linear complementary filter.

  8. Genome-wide selection of superior reference genes for expression studies in Ganoderma lucidum.

    PubMed

    Xu, Zhichao; Xu, Jiang; Ji, Aijia; Zhu, Yingjie; Zhang, Xin; Hu, Yuanlei; Song, Jingyuan; Chen, Shilin

    2015-12-15

    Quantitative real-time polymerase chain reaction (qRT-PCR) is widely used for the accurate analysis of gene expression. However, high homology among gene families might result in unsuitability of reference genes, which leads to the inaccuracy of qRT-PCR analysis. The release of the Ganoderma lucidum genome has triggered numerous studies to be done on the homology among gene families with the purpose of selecting reliable reference genes. Based on the G. lucdum genome and transcriptome database, 38 candidate reference genes including 28 novel genes were systematically selected and evaluated for qRT-PCR normalization. The result indicated that commonly used polyubiquitin (PUB), beta-actin (BAT), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were unsuitable reference genes because of the high sequence similarity and low primer specificity. According to the evaluation of RefFinder, cyclophilin 5 (CYP5) was ranked as the most stable reference gene for 27 tested samples under all experimental conditions and eighteen mycelial samples. Based on sequence analysis and expression analysis, our study suggested that gene characteristic, primer specificity of high homologous genes, allele-specificity expression of candidate genes and under-evaluation of reference genes influenced the accuracy and sensitivity of qRT-PCR analysis. This investigation not only revealed potential factors influencing the unsuitability of reference genes but also selected the superior reference genes from more candidate genes and testing samples than those used in the previous study. Furthermore, our study established a model for reference gene analysis by using the genomic sequence.

  9. MYCIN II: design and implementation of a therapy reference with complex content-based indexing.

    PubMed

    Kim, D K; Fagan, L M; Jones, K T; Berrios, D C; Yu, V L

    1998-01-01

    We describe the construction of MYCIN II, a prototype system that provides for content-based markup and search of a forthcoming clinical therapeutics textbook, Antimicrobial Therapy and Vaccines. Existing commercial search technology for digital references utilizes generic tools such as textword-based searches with geographical or statistical refinements. We suggest that the drawbacks of such systems significantly restrict their use in everyday clinical practice. This is in spite of the fact that there is a great need for the information contained within these same references. The system we describe is intended to supplement keyword searching so that certain important questions can be asked easily and can be answered reliably (in terms of precision and recall). Our method attacks this problem in a restricted domain of knowledge-clinical infectious disease. For example, we would like to be able to answer the class of questions exemplified by the following query: "What antimicrobial agents can be used to treat endocarditis caused by Eikenella corrodens?" We have compiled and analyzed a list of such questions to develop a concept-based markup scheme. This scheme was then applied within an HTML markup to electronically "highlight" passages from three textbook chapters. We constructed a functioning web-based search interface. Our system also provides semi-automated querying of PubMed using our concept markup and the user's actions as a guide.

  10. DAKOTA, a multilevel parallel object-oriented framework for design optimization, parameter estimation, uncertainty quantification, and sensitivity analysis:version 4.0 reference manual

    SciTech Connect

    Griffin, Joshua D. (Sandai National Labs, Livermore, CA); Eldred, Michael Scott; Martinez-Canales, Monica L.; Watson, Jean-Paul; Kolda, Tamara Gibson; Adams, Brian M.; Swiler, Laura Painton; Williams, Pamela J.; Hough, Patricia Diane; Gay, David M.; Dunlavy, Daniel M.; Eddy, John P.; Hart, William Eugene; Guinta, Anthony A.; Brown, Shannon L.

    2006-10-01

    The DAKOTA (Design Analysis Kit for Optimization and Terascale Applications) toolkit provides a flexible and extensible interface between simulation codes and iterative analysis methods. DAKOTA contains algorithms for optimization with gradient and nongradient-based methods; uncertainty quantification with sampling, reliability, and stochastic finite element methods; parameter estimation with nonlinear least squares methods; and sensitivity/variance analysis with design of experiments and parameter study methods. These capabilities may be used on their own or as components within advanced strategies such as surrogate-based optimization, mixed integer nonlinear programming, or optimization under uncertainty. By employing object-oriented design to implement abstractions of the key components required for iterative systems analyses, the DAKOTA toolkit provides a flexible and extensible problem-solving environment for design and performance analysis of computational models on high performance computers. This report serves as a reference manual for the commands specification for the DAKOTA software, providing input overviews, option descriptions, and example specifications.

  11. DAKOTA : a multilevel parallel object-oriented framework for design optimization, parameter estimation, uncertainty quantification, and sensitivity analysis. Version 5.0, user's reference manual.

    SciTech Connect

    Eldred, Michael Scott; Dalbey, Keith R.; Bohnhoff, William J.; Adams, Brian M.; Swiler, Laura Painton; Hough, Patricia Diane; Gay, David M.; Eddy, John P.; Haskell, Karen H.

    2010-05-01

    The DAKOTA (Design Analysis Kit for Optimization and Terascale Applications) toolkit provides a flexible and extensible interface between simulation codes and iterative analysis methods. DAKOTA contains algorithms for optimization with gradient and nongradient-based methods; uncertainty quantification with sampling, reliability, and stochastic finite element methods; parameter estimation with nonlinear least squares methods; and sensitivity/variance analysis with design of experiments and parameter study methods. These capabilities may be used on their own or as components within advanced strategies such as surrogate-based optimization, mixed integer nonlinear programming, or optimization under uncertainty. By employing object-oriented design to implement abstractions of the key components required for iterative systems analyses, the DAKOTA toolkit provides a flexible and extensible problem-solving environment for design and performance analysis of computational models on high performance computers. This report serves as a reference manual for the commands specification for the DAKOTA software, providing input overviews, option descriptions, and example specifications.

  12. Identification of suitable reference genes for gene expression studies of shoulder instability.

    PubMed

    Leal, Mariana Ferreira; Belangero, Paulo Santoro; Cohen, Carina; Figueiredo, Eduardo Antônio; Loyola, Leonor Casilla; Pochini, Alberto Castro; Smith, Marília Cardoso; Andreoli, Carlos Vicente; Belangero, Sintia Iole; Ejnisman, Benno; Cohen, Moises

    2014-01-01

    Shoulder instability is a common shoulder injury, and patients present with plastic deformation of the glenohumeral capsule. Gene expression analysis may be a useful tool for increasing the general understanding of capsule deformation, and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) has become an effective method for such studies. Although RT-qPCR is highly sensitive and specific, it requires the use of suitable reference genes for data normalization to guarantee meaningful and reproducible results. In the present study, we evaluated the suitability of a set of reference genes using samples from the glenohumeral capsules of individuals with and without shoulder instability. We analyzed the expression of six commonly used reference genes (ACTB, B2M, GAPDH, HPRT1, TBP and TFRC) in the antero-inferior, antero-superior and posterior portions of the glenohumeral capsules of cases and controls. The stability of the candidate reference gene expression was determined using four software packages: NormFinder, geNorm, BestKeeper and DataAssist. Overall, HPRT1 was the best single reference gene, and HPRT1 and B2M composed the best pair of reference genes from different analysis groups, including simultaneous analysis of all tissue samples. GenEx software was used to identify the optimal number of reference genes to be used for normalization and demonstrated that the accumulated standard deviation resulting from the use of 2 reference genes was similar to that resulting from the use of 3 or more reference genes. To identify the optimal combination of reference genes, we evaluated the expression of COL1A1. Although the use of different reference gene combinations yielded variable normalized quantities, the relative quantities within sample groups were similar and confirmed that no obvious differences were observed when using 2, 3 or 4 reference genes. Consequently, the use of 2 stable reference genes for normalization, especially HPRT1 and B2M, is a

  13. Sample size of the reference sample in a case-augmented study.

    PubMed

    Ghosh, Palash; Dewanji, Anup

    2017-03-13

    The case-augmented study, in which a case sample is augmented with a reference (random) sample from the source population with only covariates information known, is becoming popular in different areas of applied science such as pharmacovigilance, ecology, and econometrics. In general, the case sample is available from some source (for example, hospital database, case registry, etc.); however, the reference sample is required to be drawn from the corresponding source population. The required minimum size of the reference sample is an important issue in this regard. In this work, we address the minimum sample size calculation and discuss related issues. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Managing data for a multicountry longitudinal study: experience from the WHO Multicentre Growth Reference Study.

    PubMed

    Onyango, Adelheid W; Pinol, Alain J; de Onis, Mercedes

    2004-03-01

    The World Health Organization (WHO) Multicentre Growth Reference (MGRS) data management protocol was designed to create and manage a large data bank of information collected from multiple sites over a period of several years. Data collection and processing instruments were prepared centrally and used in a standardized fashion across sites. The data management system contained internal validation features for timely detection of data errors, and its standard operating procedures stipulated a method of master file updating and correction that maintained a clear trail for data auditing purposes. Each site was responsible for collecting, entering, verifying, and validating data, and for creating site-level master files. Data from the sites were sent to the MGRS Coordinating Centre every month for master file consolidation and more extensive quality control checking. All errors identified at the Coordinating Centre were communicated to the site for correction at source. The protocol imposed transparency on the sites' data management activities but also ensured access to technical help with operation and maintenance of the system. Through the rigorous implementation of what has been a highly demanding protocol, the MGRS has accumulated a large body of very high-quality data.

  15. Selection and evaluation of reference genes for improved interrogation of microbial transcriptomes: case study with the extremophile Acidithiobacillus ferrooxidans

    PubMed Central

    Nieto, Pamela A; Covarrubias, Paulo C; Jedlicki, Eugenia; Holmes, David S; Quatrini, Raquel

    2009-01-01

    Background Normalization is a prerequisite for accurate real time PCR (qPCR) expression analysis and for the validation of microarray profiling data in microbial systems. The choice and use of reference genes that are stably expressed across samples, experimental conditions and designs is a key consideration for the accurate interpretation of gene expression data. Results Here, we evaluate a carefully selected set of reference genes derived from previous microarray-based transcriptional profiling experiments performed on Acidithiobacillus ferrooxidans and identify a set of genes with minimal variability under five different experimental conditions that are frequently used in Acidithiobacilli research. Suitability of these and other previously reported reference genes to monitor the expression of four selected target genes from A. ferrooxidans grown with different energy sources was investigated. Utilization of reference genes map, rpoC, alaS and era results in improved interpretation of gene expression profiles in A. ferrooxidans. Conclusion This investigation provides a validated set of reference genes for studying A. ferrooxidans gene expression under typical biological conditions and an initial point of departure for exploring new experimental setups in this microorganism and eventually in other closely related Acidithiobacilli. The information could also be of value for future transcriptomic experiments in other bacterial systems. PMID:19555508

  16. Validation of endogenous control reference genes for normalizing gene expression studies in endometrial carcinoma.

    PubMed

    Ayakannu, Thangesweran; Taylor, Anthony H; Willets, Jonathon M; Brown, Laurence; Lambert, David G; McDonald, John; Davies, Quentin; Moss, Esther L; Konje, Justin C

    2015-09-01

    Real-time quantitative RT-PCR (qRT-PCR) is a powerful technique used for the relative quantification of target genes, using reference (housekeeping) genes for normalization to ensure the generation of accurate and robust data. A systematic examination of the suitability of endogenous reference genes for gene expression studies in endometrial cancer tissues is absent. The aims of this study were therefore to identify and evaluate from the thirty-two possible reference genes from a TaqMan(®) array panel their suitability as an internal control gene. The mathematical software packages geNorm qBasePLUS identified Pumilio homolog 1 (Drosophila) (PUM1), ubiquitin C (UBC), phosphoglycerate kinase (PGK1), mitochondrial ribosomal protein L19 (MRPL19) and peptidylpropyl isomerase A (cyclophilin A) (PPIA) as the best reference gene combination, whilst NormFinder identified MRPL19 as the best single reference gene, with importin 8 (IPO8) and PPIA being the best combination of two reference genes. BestKeeper ranked MRPL19 as the most stably expressed gene. In addition, the study was validated by examining the relative expression of a test gene, which encodes the cannabinoid receptor 1 (CB1). A significant difference in CB1 mRNA expression between malignant and normal endometrium using MRPL19, PPIA, and IP08 in combination was observed. The use of MRPL19, IPO8 and PPIA was identified as the best reference gene combination for the normalization of gene expression levels in endometrial carcinoma. This study demonstrates that the arbitrary selection of endogenous control reference genes for normalization in qRT-PCR studies of endometrial carcinoma, without validation, risks the production of inaccurate data and should therefore be discouraged.

  17. Vertical Field of View Reference Point Study for Flight Path Control and Hazard Avoidance

    NASA Technical Reports Server (NTRS)

    Comstock, J. Raymond, Jr.; Rudisill, Marianne; Kramer, Lynda J.; Busquets, Anthony M.

    2002-01-01

    Researchers within the eXternal Visibility System (XVS) element of the High-Speed Research (HSR) program developed and evaluated display concepts that will provide the flight crew of the proposed High-Speed Civil Transport (HSCT) with integrated imagery and symbology to permit path control and hazard avoidance functions while maintaining required situation awareness. The challenge of the XVS program is to develop concepts that would permit a no-nose-droop configuration of an HSCT and expanded low visibility HSCT operational capabilities. This study was one of a series of experiments exploring the 'design space' restrictions for physical placement of an XVS display. The primary experimental issues here was 'conformality' of the forward display vertical position with respect to the side window in simulated flight. 'Conformality' refers to the case such that the horizon and objects appear in the same relative positions when viewed through the forward windows or display and the side windows. This study quantified the effects of visual conformality on pilot flight path control and hazard avoidance performance. Here, conformality related to the positioning and relationship of the artificial horizon line and associated symbology presented on the forward display and the horizon and associated ground, horizon, and sky textures as they would appear in the real view through a window presented in the side window display. No significant performance consequences were found for the non-conformal conditions.

  18. Environmental Design and Educational Performance, with Particular Reference to "Green" Schools in Hampshire and Essex

    ERIC Educational Resources Information Center

    Edwards, Brian W.

    2006-01-01

    This article examines the argument that "green" schools enhance educational performance. Having set the context of the relationship between environmentalism and the design of schools in the twentieth century, the article explores the performance of a number of green schools built in the UK between 1980 and 1995. The aim is to discover…

  19. An Electronic Service Quality Reference Model for Designing E-Commerce Websites Which Maximizes Customer Satisfaction

    ERIC Educational Resources Information Center

    Shaheen, Amer N.

    2011-01-01

    This research investigated Electronic Service Quality (E-SQ) features that contribute to customer satisfaction in an online environment. The aim was to develop an approach which improves E-CRM processes and enhances online customer satisfaction. The research design adopted mixed methods involving qualitative and quantitative methods to…

  20. Durability-Based Design Properties of Reference Crossply Carbon-Fiber Composite

    SciTech Connect

    Corum, J.M.

    2001-04-16

    This report provides recommended durability-based design properties and criteria for a crossply carbon-fiber composite for possible automotive structural applications. Although the composite utilized aerospace-grade carbon-fiber reinforcement, it was made by a rapid-molding process suitable for high-volume automotive use. The material is the first in a planned progression of candidate composites to be characterized as part of an Oak Ridge National Laboratory project entitled Durability of Carbon-Fiber Composites. The overall goal of the project, which is sponsored by the U.S. Department of Energy's Office of Advanced Automotive Technologies and is closely coordinated with the Advanced Composites Consortium, is to develop durability-driven design data and criteria to assure the long-term integrity of carbon-fiber-based composite systems for automotive structural applications. The composite addressed in this report is a ({+-}45{degree})3S crossply consisting of continuous Thornel T300 fibers in a Baydur 420 IMR urethane matrix. This composite is highly anisotropic with two dominant fiber orientations--0/90{degree} and {+-}45{degree}. Properties and models were developed for both orientations. This document is in two parts. Part 1 provides design data and correlations, while Part 2 provides the underlying experimental data and models. The durability issues addressed include the effects of short-time, cyclic, and sustained loadings; temperature; fluid environments; and low-energy impacts (e.g., tool drops and kickups of roadway debris) on deformation, strength, and stiffness. Guidance for design analysis, time-independent and time-dependent allowable stresses, rules for cyclic loadings, and damage-tolerance design guidance are provided.

  1. Novel Compressor Blade Design Study

    NASA Astrophysics Data System (ADS)

    Srinivas, Abhay

    Jet engine efficiency goals are driving compressors to higher pressure ratios and engines to higher bypass ratios, each one driving to smaller cores. This is leading to larger tip gaps relative to the blade height. These larger relative tip clearances would negate some of the cycle improvements, and ways to mitigate this effect must be found. A novel split tip blade geometry has been created which helps improve the efficiency at large clearances while also improving operating range. Two identical blades are leaned in opposite directions starting at 85% span. They are cut at mid chord and the 2 halves then merged together so a split tip is created. The result is similar to the alula feathers on a soaring bird. The concept is that the split tip will energize the tip flow and increase range. For higher relative tip clearance, this will also improve efficiency. The 6th rotor of a highly loaded 10 stage machine was chosen as the baseline for this study. Three dimensional CFD simulations were performed using CD Adapco's Star-CCM+ at 5 clearances for the baseline and split tip geometry. The choking flow and stall margin of the split tip blade was higher than that of the baseline blade for all tip clearances. The pressure ratio of the novel blade was higher than that of the baseline blade near choke, but closer to stall it decreased. The sensitivity of peak efficiency to clearance was improved. At tight clearances of 0.62% of blade height, the maximum efficiency of the new design was less than the baseline blade, but as the tip clearance was increased above 2.5%, the maximum efficiency increased. Structural analysis was also performed to ascertain the feasibility of the design.

  2. Light weight radioisotope heater unit (LWRHU): a technical description of the reference design

    SciTech Connect

    Tate, R.E.

    1982-01-01

    The Light Weight Radioisotope Heater Unit (LWRHU), a new radioisotope heater unit for use in space missions, is a /sup 238/PuO/sub 2/-fueled unit designed to provide a thermal watt in dispersed locations on a spacecraft. The LWRHU is required to maintain the temperature of a component at a level where the component will function reliably in space. Two major constraints are placed on the unit's design; it must be as light as possible and must provide enough protection to immobilize the plutonium fuel to the maximum extent in all phases of the unit's lifetime. The four components are pelletized fuel, platinum-alloy encapsulation, pyrolytic graphite thermal insulation, and high-technology graphite ablation shell. The LWRHU is a cylinder 32 mm (1.26 in.) high and 26 mm (1.02 in.) in diameter. It weighs slightly less than 40 g(.09 lb).

  3. Learning Science by Designing Artifacts (LSDA)--A Case Study of the Development of a Design-Based Science Curriculum.

    ERIC Educational Resources Information Center

    Mamlok, Rachel; Dershimer, Charles; Fortus, David; Krajcik, Joe; Marx, Ron

    The purpose of this study was to document the iterative development of a design-based science curriculum called Learning Science by Designing Artifacts (LSDA). The study refers to the enactment of the Safer Cell Phones curriculum in a high school located in the Midwest. The curriculum was a 5- or 9-week unit in an 18-week science elective course.…

  4. Schematic designs for penetration seals for a reference repository in bedded salt

    SciTech Connect

    Kelsall, P.C.; Case, J.B.; Meyer, D.; Coons, W.E.

    1982-11-01

    The isolation of radioactive wastes in geologic repositories requires that man-made penetrations such as shafts, tunnels, or boreholes are adequately sealed. This report describes schematic seal designs for a repository in bedded salt referenced to the straitigraphy of southeastern New Mexico. The designs are presented for extensive peer review and will be updated as site-specific conceptual designs when a site for a repository in salt has been selected. The principal material used in the seal system is crushed salt obtained from excavating the repository. It is anticipated that crushed salt will consolidate as the repository rooms creep close to the degree that mechanical and hydrologic properties will eventually match those of undisturbed, intact salt. For southeastern New Mexico salt, analyses indicate that this process will require approximately 1000 years for a seal located at the base of one of the repository shafts (where there is little increase in temperature due to waste emplacement) and approximately 400 years for a seal located in an access tunnel within the repository. Bulkheads composed of contrete or salt bricks are also included in the seal system as components which will have low permeability during the period required for salt consolidation.

  5. Appropriate Real-Time PCR Reference Genes for Fluoride Treatment Studies Performed In Vitro or In Vivo

    PubMed Central

    Faibish, D.; Suzuki, M.; Bartlett, J.D.

    2015-01-01

    Objective Quantitative real-time PCR (qPCR) is routinely performed for experiments designed to identify the molecular mechanisms involved in the pathogenesis of dental fluorosis. Expression of reference gene(s) is expected to remain unchanged in fluoride-treated cells or in rodents relative to the corresponding untreated controls. The aim of this study was to select optimal reference genes for fluoride experiments performed in vitro and in vivo. Design Five candidate genes were evaluated: B2m, Eef1a1, Gapdh, Hprt and Tbp. For in vitro experiments, LS8 cells derived from mouse enamel organ were treated with 0, 1, 3 and/or 5 mM sodium fluoride (NaF) for 6 or 18 hours followed by RNA isolation. For in vivo experiments, six-week old rats were treated with 0 or 100 ppm fluoride as NaF for six weeks at which time RNA was isolated from enamel organs. RNA from cells and enamel organs were reverse-transcribed and stability of gene expression for the candidate reference genes was evaluated by qPCR in treated versus non-treated samples. Results The most stably expressed genes in vitro according to geNorm were B2m and Tbp, and according to Normfinder were Hprt and Gapdh. The most stable genes in vivo were Eef1a1 and Gapdh. Expression of Ddit3, a gene previously shown to be induced by fluoride, was demonstrated to be accurately calculated only when using an optimal reference gene. Conclusions This study identifies suitable reference genes for relative quantification of gene expression by qPCR after fluoride treatment both in cultured cells and in the rodent enamel organ. PMID:26615575

  6. Altair Descent and Ascent Reference Trajectory Design and Initial Dispersion Analyses

    NASA Technical Reports Server (NTRS)

    Kos, Larry D.; Polsgrove, Tara T.; Sostaric, Ronald r.; Braden, Ellen M.; Sullivan, Jacob J.; Lee, Thanh T.

    2010-01-01

    The Altair Lunar Lander is the linchpin in the Constellation Program (CxP) for human return to the Moon. Altair is delivered to low Earth orbit (LEO) by the Ares V heavy lift launch vehicle, and after subsequent docking with Orion in LEO, the Altair/Orion stack is delivered through translunar injection (TLI). The Altair/Orion stack separating from the Earth departure stage (EDS) shortly after TLI and continues the flight to the Moon as a single stack. Altair performs the lunar orbit insertion (LOI) maneuver, targeting a 100-km circular orbit. This orbit will be a polar orbit for missions landing near the lunar South Pole. After spending nearly 24 hours in low lunar orbit (LLO), the lander undocks from Orion and performs a series of small maneuvers to set up for descending to the lunar surface. This descent begins with a small deorbit insertion (DOI) maneuver, putting the lander on an orbit that has a perilune of 15.24 km (50,000 ft), the altitude where the actual powered descent initiation (PDI) commences. At liftoff from Earth, Altair has a mass of 45 metric tons (mt). However after LOI (without Orion attached), the lander mass is slightly less than 33 mt at PDI. The lander currently has a single descent module main engine, with TBD lb(sub f) thrust (TBD N), providing a thrust-to-weight ratio of approximately TBD Earth g's at PDI. LDAC-3 (Lander design and analysis cycle #3) is the most recently closed design sizing and mass properties iteration. Upgrades for loss of crew (LDAC-2) and loss of mission (LDAC-3) have been incorporated into the lander baseline design (and its Master Equipment List). Also, recently, Altair has been working requirements analyses (LRAC-1). All nominal data here are from the LDAC-3 analysis cycle. All dispersions results here are from LRAC-1 analyses.

  7. Analysis of Reference Design for Nuclear-Assisted Hydrogen Production at 750°C Reactor Outlet Temperature

    SciTech Connect

    Michael G. McKellar; Edwin A. Harvego

    2010-05-01

    The use of High Temperature Electrolysis (HTE) for the efficient production of hydrogen without the greenhouse gas emissions associated with conventional fossil-fuel hydrogen production techniques has been under investigation at the Idaho National Engineering Laboratory (INL) for the last several years. The activities at the INL have included the development, testing and analysis of large numbers of solid oxide electrolysis cells, and the analyses of potential plant designs for large scale production of hydrogen using a high-temperature gas-cooled reactor (HTGR) to provide the process heat and electricity to drive the electrolysis process. The results of this research led to the selection in 2009 of HTE as the preferred concept in the U.S. Department of Energy (DOE) hydrogen technology down-selection process. However, the down-selection process, along with continued technical assessments at the INL, has resulted in a number of proposed modifications and refinements to improve the original INL reference HTE design. These modifications include changes in plant configuration, operating conditions and individual component designs. This report describes the resulting new INL reference design coupled to two alternative HTGR power conversion systems, a Steam Rankine Cycle and a Combined Cycle (a Helium Brayton Cycle with a Steam Rankine Bottoming Cycle). Results of system analyses performed to optimize the design and to determine required plant performance and operating conditions when coupled to the two different power cycles are also presented. A 600 MWt high temperature gas reactor coupled with a Rankine steam power cycle at a thermal efficiency of 44.4% can produce 1.85 kg/s of hydrogen and 14.6 kg/s of oxygen. The same capacity reactor coupled with a combined cycle at a thermal efficiency of 42.5% can produce 1.78 kg/s of hydrogen and 14.0 kg/s of oxygen.

  8. Human Health and Performance Aspects of Mars Design Reference Mission of July, 1997

    NASA Technical Reports Server (NTRS)

    Charles, John B.

    1999-01-01

    The human element is the most complex element of the mission design Mars missions will pose significant physiological and psychological challenges to crew members Some challenges (human engineering, life support) must be overcome (potential "non-starters") Some challenges (bone, radiation) may be show-stoppers ISS will only Indirectly address Mars questions before any "Go/No Go" decision Significant amount of ground-based and specialized flight research will be required -- Critical Path Roadmap project will direct HSLSPO's research toward Mars exploration objectives

  9. Destination Deimos: A Design Reference Architecture for Initial Human Exploration of the Mars System

    NASA Technical Reports Server (NTRS)

    Logan, James S.; Adamo, D. R.

    2011-01-01

    The two biggest challenges to successful human operations in interplanetary space are flight dynamics, constrained by the cold hard physics of the rocket equation, and bioastronautics, the psychophysiological realities of human adaptation, or lack thereof, to the deep space environment. Without substantial innovation in project/mission architecture and vehicle design, human exploration of the Mars system could be problematic for decades. Although a human landing on Mars is inevitable, humans-in-the-loop telerobotic exploration from the outer Martian moon Deimos is the best way to begin. Precursor robotic missions for reconnaissance and local site preparation will be required.

  10. Economic Analysis of the Reference Design for a Nuclear-Driven High-Temperature-Electrolysis Hydrogen Production Plant

    SciTech Connect

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-01-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540°C and 900°C, respectively. The electrolysis unit used to produce hydrogen consists of 4,009,177 cells with a per-cell active area of 225 cm2. A nominal cell area-specific resistance, ASR, value of 0.4 Ohm•cm2 with a current density of 0.25 A/cm2 was used, and isothermal boundary conditions were assumed. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating current, AC, to direct current, DC, conversion is 96%. The overall system thermal-to-hydrogen production efficiency (based on the low heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of the plant was also performed using the H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost using realistic financial and cost estimating assumptions. A required cost of $3.23 per kg of hydrogen produced was calculated assuming an internal rate of return of 10%. Approximately 73% of this cost ($2.36/kg) is the result of capital costs associated

  11. Turning Electromyography Reports Upside Down: A Pilot Study Surveying Referring Providers.

    PubMed

    Shenoy, Anant M; Baquis, Kate G; Baquis, George D

    2016-01-01

    Providers are expressing a desire for more efficient ways to retrieve relevant clinical data from the Electronic Health Record. In an effort to improve our Electromyography and Nerve Conduction Study reports, we surveyed referring providers on the effects of having the IMPRESSION at the start of the report. Our survey respondents felt that using this format for an Electromyography and Nerve Conduction Study report significantly improved the quality of the report while saving them time and/or mouse clicks when interpreting the report. Electro diagnosticians might consider using this format for their Electromyography and Nerve Conduction Study reports to improve referring provider satisfaction.

  12. Collaborative studies on the development of national reference standards for potency determination of H7N9 influenza vaccine

    PubMed Central

    Li, Changgui; Xu, Kangwei; Hashem, Anwar; Shao, Ming; Liu, Shuzhen; Zou, Yong; Gao, Qiang; Zhang, Yongchao; Yuan, Liyong; Xu, Miao; Li, Xuguang; Wang, Junzhi

    2015-01-01

    The outbreak of human infections of a novel avian influenza virus A (H7N9) prompted the development of the vaccines against this virus. Like all types of influenza vaccines, H7N9 vaccine must be tested for its potency prior to being used in humans. However, the unavailability of international reference reagents for the potency determination of H7N9 vaccines substantially hinders the progress in vaccine development. To facilitate clinical development, we enlisted 5 participants in a collaborative study to develop critical reagents used in Single Radial Immunodiffusion (SRID), the currently acceptable assay for potency determination of influenza vaccine. Specifically, the hemagglutinin (HA) content of one vaccine bulk for influenza A (H7N9), herein designated as Primary Liquid Standard (PLS), was determined by SDS-PAGE. In addition, the freeze-dried antigen references derived from PLS were prepared to enhance the stability for long term storage. The final HA content of lyophilized antigen references were calibrated against PLS by SRID assay in a collaborative study. Importantly, application of these national reference standards to potency analyses greatly facilitated the development of H7N9 vaccines in China. PMID:25970793

  13. Collaborative studies on the development of national reference standards for potency determination of H7N9 influenza vaccine.

    PubMed

    Li, Changgui; Xu, Kangwei; Hashem, Anwar; Shao, Ming; Liu, Shuzhen; Zou, Yong; Gao, Qiang; Zhang, Yongchao; Yuan, Liyong; Xu, Miao; Li, Xuguang; Wang, Junzhi

    2015-01-01

    The outbreak of human infections of a novel avian influenza virus A (H7N9) prompted the development of the vaccines against this virus. Like all types of influenza vaccines, H7N9 vaccine must be tested for its potency prior to being used in humans. However, the unavailability of international reference reagents for the potency determination of H7N9 vaccines substantially hinders the progress in vaccine development. To facilitate clinical development, we enlisted 5 participants in a collaborative study to develop critical reagents used in Single Radial Immunodiffusion (SRID), the currently acceptable assay for potency determination of influenza vaccine. Specifically, the hemagglutinin (HA) content of one vaccine bulk for influenza A (H7N9), herein designated as Primary Liquid Standard (PLS), was determined by SDS-PAGE. In addition, the freeze-dried antigen references derived from PLS were prepared to enhance the stability for long term storage. The final HA content of lyophilized antigen references were calibrated against PLS by SRID assay in a collaborative study. Importantly, application of these national reference standards to potency analyses greatly facilitated the development of H7N9 vaccines in China.

  14. A study of commuter airplane design optimization

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Wyatt, R. D.; Griswold, D. A.; Hammer, J. L.

    1977-01-01

    Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program.

  15. Identification of reference genes and validation for gene expression studies in diverse axolotl (Ambystoma mexicanum) tissues.

    PubMed

    Guelke, Eileen; Bucan, Vesna; Liebsch, Christina; Lazaridis, Andrea; Radtke, Christine; Vogt, Peter M; Reimers, Kerstin

    2015-04-10

    For the precise quantitative RT-PCR normalization a set of valid reference genes is obligatory. Moreover have to be taken into concern the experimental conditions as they bias the regulation of reference genes. Up till now, no reference targets have been described for the axolotl (Ambystoma mexicanum). In a search in the public database SalSite for genetic information of the axolotl we identified fourteen presumptive reference genes, eleven of which were further tested for their gene expression stability. This study characterizes the expressional patterns of 11 putative endogenous control genes during axolotl limb regeneration and in an axolotl tissue panel. All 11 reference genes showed variable expression. Strikingly, ACTB was to be found most stable expressed in all comparative tissue groups, so we reason it to be suitable for all different kinds of axolotl tissue-type investigations. Moreover do we suggest GAPDH and RPLP0 as suitable for certain axolotl tissue analysis. When it comes to axolotl limb regeneration, a validated pair of reference genes is ODC and RPLP0. With these findings, new insights into axolotl gene expression profiling might be gained.

  16. Student-Designed River Study.

    ERIC Educational Resources Information Center

    Turkall, Sheila Florian

    1996-01-01

    Describes an integrated student-designed investigation in which students explore different aspects of the Chagrin River including the river ecosystem, velocity and average depth, river flooding, water quality, and economic and political factors. (JRH)

  17. Reference allocations and use of a disparity measure to inform the design of allocation funding formulas in public health programs.

    PubMed

    Buehler, James W; Bernet, Patrick M; Ogden, Lydia L

    2012-01-01

    Funding formulas are commonly used by federal agencies to allocate program funds to states. As one approach to evaluating differences in allocations resulting from alternative formula calculations, we propose the use of a measure derived from the Gini index to summarize differences in allocations relative to 2 referent allocations: one based on equal per-capita funding across states and another based on equal funding per person living in poverty, which we define as the "proportionality of allocation" (PA). These referents reflect underlying values that often shape formula-based allocations for public health programs. The size of state populations serves as a general proxy for the amount of funding needed to support programs across states. While the size of state populations living in poverty is correlated with overall population size, allocations based on states' shares of the national population living in poverty reflect variations in funding need shaped by the association between poverty and multiple adverse health outcomes. The PA measure is a summary of the degree of dispersion in state-specific allocations relative to the referent allocations and provides a quick assessment of the impact of selecting alternative funding formula designs. We illustrate the PA values by adjusting a sample allocation, using various measures of the salary costs and in-state wealth, which might modulate states' needs for federal funding.

  18. Selection of Reliable Reference Genes for Gene Expression Studies on Rhododendron molle G. Don

    PubMed Central

    Xiao, Zheng; Sun, Xiaobo; Liu, Xiaoqing; Li, Chang; He, Lisi; Chen, Shangping; Su, Jiale

    2016-01-01

    The quantitative real-time polymerase chain reaction (qRT-PCR) approach has become a widely used method to analyze expression patterns of target genes. The selection of an optimal reference gene is a prerequisite for the accurate normalization of gene expression in qRT-PCR. The present study constitutes the first systematic evaluation of potential reference genes in Rhododendron molle G. Don. Eleven candidate reference genes in different tissues and flowers at different developmental stages of R. molle were assessed using the following three software packages: GeNorm, NormFinder, and BestKeeper. The results showed that EF1-α (elongation factor 1-alpha), 18S (18s ribosomal RNA), and RPL3 (ribosomal protein L3) were the most stable reference genes in developing rhododendron flowers and, thus, in all of the tested samples, while tublin (TUB) was the least stable. ACT5 (actin), RPL3, 18S, and EF1-α were found to be the top four choices for different tissues, whereas TUB was not found to favor qRT-PCR normalization in these tissues. Three stable reference genes are recommended for the normalization of qRT-PCR data in R. molle. Furthermore, the expression profiles of RmPSY (phytoene synthase) and RmPDS (phytoene dehydrogenase) were assessed using EF1-α, 18S, ACT5, RPL3, and their combination as internals. Similar trends were found, but these trends varied when the least stable reference gene TUB was used. The results further prove that it is necessary to validate the stability of reference genes prior to their use for normalization under different experimental conditions. This study provides useful information for reliable qRT-PCR data normalization in gene studies of R. molle. PMID:27803707

  19. Bacterial reference genes for gene expression studies by RT-qPCR: survey and analysis.

    PubMed

    Rocha, Danilo J P; Santos, Carolina S; Pacheco, Luis G C

    2015-09-01

    The appropriate choice of reference genes is essential for accurate normalization of gene expression data obtained by the method of reverse transcription quantitative real-time PCR (RT-qPCR). In 2009, a guideline called the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) highlighted the importance of the selection and validation of more than one suitable reference gene for obtaining reliable RT-qPCR results. Herein, we searched the recent literature in order to identify the bacterial reference genes that have been most commonly validated in gene expression studies by RT-qPCR (in the first 5 years following publication of the MIQE guidelines). Through a combination of different search parameters with the text mining tool MedlineRanker, we identified 145 unique bacterial genes that were recently tested as candidate reference genes. Of these, 45 genes were experimentally validated and, in most of the cases, their expression stabilities were verified using the software tools geNorm and NormFinder. It is noteworthy that only 10 of these reference genes had been validated in two or more of the studies evaluated. An enrichment analysis using Gene Ontology classifications demonstrated that genes belonging to the functional categories of DNA Replication (GO: 0006260) and Transcription (GO: 0006351) rendered a proportionally higher number of validated reference genes. Three genes in the former functional class were also among the top five most stable genes identified through an analysis of gene expression data obtained from the Pathosystems Resource Integration Center. These results may provide a guideline for the initial selection of candidate reference genes for RT-qPCR studies in several different bacterial species.

  20. Religious Studies: The Shaping of a Field and a Guide to Reference Resources.

    ERIC Educational Resources Information Center

    Lippy, Charles H.

    1992-01-01

    Discusses the development of religious studies as an academic discipline. Examines the work of leading thinkers in the field, including anthropologists Sir James Fraser and Edward Burnett Taylor, sociologist Max Weber, and psychologist Erik Erikson. Identifies some of the many reference works that deal with religious studies. (SG)

  1. A REFERENCE GRAMMAR OF HINDI, A STUDY OF SOME SELECTED TOPICS IN HINDI GRAMMAR.

    ERIC Educational Resources Information Center

    BAHL, KALI C.

    A REFERENCE GRAMMAR WAS COMPILED FOR MODERN STANDARD HINDI GRAMMAR. THIS GRAMMAR IS BASED UPON A VIEW THAT HINDI IS A LITERARY LANGUAGE, AND THAT ITS SYNTAX SHOULD THEREFORE BE STUDIED NOT ONLY AS THE SYNTAX OF A COLLOQUIAL LANGUAGE BUT ALSO AS THE SYNTAX OF A LITERARY LANGUAGE. THE MATERIAL FOR THE STUDY WAS TAKEN FROM LITERARY TEXTS. SOME…

  2. Study of the influence of reference system in surface finishing parameters evaluation

    NASA Astrophysics Data System (ADS)

    Sanz, A.; Fernández, R.; Pindado, S.; Núñez, P.

    2012-04-01

    In the present paper the influence of the reference system with regard to the characterization of the surface finishing is analyzed. The effect of the reference system's choice on the most representative surface finishing parameters (e.g. roughness average Ra and root mean square values Rq) is studied. The study can also be applied to their equivalent parameters in waviness and primary profiles. Based on ISO and ASME standards, three different types of regression lines (central, mean and orthogonal) are theoretically and experimentally analyzed, identifying the validity and applicability fields of each one depending on profile's geometry.

  3. Pilot study for U.S. Geological Survey Standard Reference Water Samples for pesticides

    USGS Publications Warehouse

    Friedman, L.C.; Fishman, M. J.; Boyle, D.K.

    1984-01-01

    The U. S. Geological Survey has been preparing and maintaining a library of standard reference water samples for inorganic constituents for 19 years. Recently, a pilot study was conducted to see if the reference-sample program could be expanded to include pesticides and other organic materials. Two samples containing organochlorine and organophosphorus insecticides, and chlorophenoxy acid herbicides were distributed to a number of laboratories in the United States. One of the samples also contained polychlorinated biphenyls. Interlaboratory data obtained from these round robin studies are presented with intralaboratory information on long-term stability.

  4. Epidemiological study air disaster in Amsterdam (ESADA): study design

    PubMed Central

    Slottje, Pauline; Huizink, Anja C; Twisk, Jos WR; Witteveen, Anke B; van der Ploeg, Henk M; Bramsen, Inge; Smidt, Nynke; Bijlsma, Joost A; Bouter, Lex M; van Mechelen, Willem; Smid, Tjabe

    2005-01-01

    Background In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. Methods/Design Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. Discussion In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers. PMID:15921536

  5. Design and performance of an arcjet nuclear electric propulsion system for a mid-1990's reference mission

    NASA Technical Reports Server (NTRS)

    Deininger, William D.; Vondra, Robert J.

    1987-01-01

    The design and performance of an arcjet nuclear-electric-propulsion spacecraft, suitable for use in the Space Nuclear Power System (SNPS) reference mission, are outlined. The vehicle design was based on a 30-kW ammonia arcjet system operating at an Isp of 1050 s and an efficiency of 45 percent. The arcjet/gimbal system, power-processing unit, and propellant-feed system are described. A 100-kWe SNPS was assumed, and the spacecraft mass was baselined at 5250 kg (excluding the propellant-feed system). A radiation/arcjet efflux diagnostics package was included in the performance analysis. This spacecraft, assuming a Shuttle launch from KSC, can perform a 50-deg inclination change and reach a final orbit of 35,860 km with a 120-d trip time providing a 4-mo active load for the SNPS. Alternatively, a Titan IV launch would provide a mass margin of 120 kg to a 10,000-km, 58-deg final orbit in 74 d. This spacecraft meets the reference-mission constraint of low developmental risk, and is scalable to power levels projected for future space platforms.

  6. Final safety analysis report for the Galileo Mission: Volume 1, Reference design document

    SciTech Connect

    Not Available

    1988-05-01

    The Galileo mission uses nuclear power sources called Radioisotope Thermoelectric Generators (RTGs) to provide the spacecraft's primary electrical power. Because these generators contain nuclear material, a Safety Analysis Report (SAR) is required. A preliminary SAR and an updated SAR were previously issued that provided an evolving status report on the safety analysis. As a result of the Challenger accident, the launch dates for both Galileo and Ulysses missions were later rescheduled for November 1989 and October 1990, respectively. The decision was made by agreement between the DOE and the NASA to have a revised safety evaluation and report (FSAR) prepared on the basis of these revised vehicle accidents and environments. The results of this latest revised safety evaluation are presented in this document (Galileo FSAR). Volume I, this document, provides the background design information required to understand the analyses presented in Volumes II and III. It contains descriptions of the RTGs, the Galileo spacecraft, the Space Shuttle, the Inertial Upper Stage (IUS), the trajectory and flight characteristics including flight contingency modes, and the launch site. There are two appendices in Volume I which provide detailed material properties for the RTG.

  7. On the Design of Attitude-Heading Reference Systems Using the Allan Variance.

    PubMed

    Hidalgo-Carrió, Javier; Arnold, Sascha; Poulakis, Pantelis

    2016-04-01

    The Allan variance is a method to characterize stochastic random processes. The technique was originally developed to characterize the stability of atomic clocks and has also been successfully applied to the characterization of inertial sensors. Inertial navigation systems (INS) can provide accurate results in a short time, which tend to rapidly degrade in longer time intervals. During the last decade, the performance of inertial sensors has significantly improved, particularly in terms of signal stability, mechanical robustness, and power consumption. The mass and volume of inertial sensors have also been significantly reduced, offering system-level design and accommodation advantages. This paper presents a complete methodology for the characterization and modeling of inertial sensors using the Allan variance, with direct application to navigation systems. Although the concept of sensor fusion is relatively straightforward, accurate characterization and sensor-information filtering is not a trivial task, yet they are essential for good performance. A complete and reproducible methodology utilizing the Allan variance, including all the intermediate steps, is described. An end-to-end (E2E) process for sensor-error characterization and modeling up to the final integration in the sensor-fusion scheme is explained in detail. The strength of this approach is demonstrated with representative tests on novel, high-grade inertial sensors. Experimental navigation results are presented from two distinct robotic applications: a planetary exploration rover prototype and an autonomous underwater vehicle (AUV).

  8. Advanced Design Studies. Final report

    SciTech Connect

    Steiner, Don

    2012-12-01

    The ARIES-CS project was a multi-year multi-institutional project to assess the feasibility of a compact stellarator as a fusion power plant. The work herein describes efforts to help design one aspect of the device, the divertor, which is responsible for the removal of particle and heat flux from the system, acting as the first point of contact between the magnetically confined hot plasma and the outside world. Specifically, its location and topology are explored, extending previous work on the sub ject. An optimized design is determined for the thermal particle flux using a suite of 3D stellarator design codes which trace magnetic field lines from just inside the confined plasma edge to their strike points on divertor plates. These divertor plates are specified with a newly developed plate design code. It is found that a satisfactory thermal design exists which maintains the plate temperature and heat load distribution below tolerable engineering limits. The design is unique, including a toroidal taper on the outboard plates which was found to be important to our results. The maximum thermal heat flux for the final design was 3.61 M W/m2 and the maximum peaking factor was 10.3, below prescribed limits of 10 M W/m2 and 15.6, respectively. The median length of field lines reaching the plates is about 250 m and their average angle of inclination to the surface is 2 deg. Finally, an analysis of the fast alphas, resulting from fusion in the core, which escape the plasma was performed. A method is developed for obtaining the mapping from magnetic coordinates to real-space coordinates for the ARIES-CS. This allows the alpha exit locations to be identified in real space for the first time. These were then traced using the field line algorithm as well as a guiding center routine accounting for their mass, charge, and specific direction and energy. Results show that the current design is inadequate for accommodating the alpha heat flux, capturing at most 1/3 of lost alphas

  9. Assessment of Suitable Reference Genes for Quantitative Gene Expression Studies in Melon Fruits

    PubMed Central

    Kong, Qiusheng; Gao, Lingyun; Cao, Lei; Liu, Yue; Saba, Hameed; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Melon (Cucumis melo L.) is an attractive model plant for investigating fruit development because of its morphological, physiological, and biochemical diversity. Quantification of gene expression by quantitative reverse transcription polymerase chain reaction (qRT-PCR) with stably expressed reference genes for normalization can effectively elucidate the biological functions of genes that regulate fruit development. However, the reference genes for data normalization in melon fruits have not yet been systematically validated. This study aims to assess the suitability of 20 genes for their potential use as reference genes in melon fruits. Expression variations of these genes were measured in 24 samples that represented different developmental stages of fertilized and parthenocarpic melon fruits by qRT-PCR analysis. GeNorm identified ribosomal protein L (CmRPL) and cytosolic ribosomal protein S15 (CmRPS15) as the best pair of reference genes, and as many as five genes including CmRPL, CmRPS15, TIP41-like family protein (CmTIP41), cyclophilin ROC7 (CmCYP7), and ADP ribosylation factor 1 (CmADP) were required for more reliable normalization. NormFinder ranked CmRPS15 as the best single reference gene, and RAN GTPase gene family (CmRAN) and TATA-box binding protein (CmTBP2) as the best combination of reference genes in melon fruits. Their effectiveness was further validated by parallel analyses on the activities of soluble acid invertase and sucrose phosphate synthase, and expression profiles of their respective encoding genes CmAIN2 and CmSPS1, as well as sucrose contents during melon fruit ripening. The validated reference genes will help to improve the accuracy of gene expression studies in melon fruits. PMID:27536316

  10. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    NASA Technical Reports Server (NTRS)

    Petersen, Walter; Wolff, David; Krajewski, Witek; Gatlin, Patrick

    2015-01-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  11. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    NASA Astrophysics Data System (ADS)

    Petersen, Walt; Krajewski, Witek; Wolff, David; Gatlin, Patrick

    2015-04-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  12. Advances on ELIC Design Studies

    SciTech Connect

    Bogacz, S. Alex; Bogacz, S.; Chevtsov, P.; Derbenev, Ya.; Evtushenko, P.; Krafft, G.; Hutton, A.; Li, R.; Merminga, L.; Musson, J.; Yunn, B.; Zhang, Y.; Sayed, H.; Qiang, J.

    2008-06-16

    A conceptual design of a ring-ring electron-ion collider based on CEBAF with a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 has been proposed at JLab to fulfil science requirements. Here, we summarize design progress including collider ring and interaction region optics with chromatic aberration compensation. Electron polarization in the Figure-8 ring, stacking of ion beams in an accumulator-cooler ring, beam-beam simulations and a faster kicker for the circulator electron cooler ring are also discussed.

  13. A Panel of Stably Expressed Reference Genes for Real-Time qPCR Gene Expression Studies of Mallards (Anas platyrhynchos).

    PubMed

    Chapman, Joanne R; Helin, Anu S; Wille, Michelle; Atterby, Clara; Järhult, Josef D; Fridlund, Jimmy S; Waldenström, Jonas

    2016-01-01

    Determining which reference genes have the highest stability, and are therefore appropriate for normalising data, is a crucial step in the design of real-time quantitative PCR (qPCR) gene expression studies. This is particularly warranted in non-model and ecologically important species for which appropriate reference genes are lacking, such as the mallard--a key reservoir of many diseases with relevance for human and livestock health. Previous studies assessing gene expression changes as a consequence of infection in mallards have nearly universally used β-actin and/or GAPDH as reference genes without confirming their suitability as normalisers. The use of reference genes at random, without regard for stability of expression across treatment groups, can result in erroneous interpretation of data. Here, eleven putative reference genes for use in gene expression studies of the mallard were evaluated, across six different tissues, using a low pathogenic avian influenza A virus infection model. Tissue type influenced the selection of reference genes, whereby different genes were stable in blood, spleen, lung, gastrointestinal tract and colon. β-actin and GAPDH generally displayed low stability and are therefore inappropriate reference genes in many cases. The use of different algorithms (GeNorm and NormFinder) affected stability rankings, but for both algorithms it was possible to find a combination of two stable reference genes with which to normalise qPCR data in mallards. These results highlight the importance of validating the choice of normalising reference genes before conducting gene expression studies in ducks. The fact that nearly all previous studies of the influence of pathogen infection on mallard gene expression have used a single, non-validated reference gene is problematic. The toolkit of putative reference genes provided here offers a solid foundation for future studies of gene expression in mallards and other waterfowl.

  14. Unpacking Frames of Reference to Inform the Design of Virtual World Learning in Higher Education

    ERIC Educational Resources Information Center

    Wimpenny, Katherine; Savin-Baden, Maggi; Mawer, Matt; Steils, Nicole; Tombs, Gemma

    2012-01-01

    In the changing context of globalised higher education, a series of pedagogical shifts have occurred, and with them, a number of interactive learning approaches have emerged. This article reports on findings taken from a large-scale study that explored the socio-political impact of virtual world learning on higher education in the UK, specifically…

  15. Primary care REFerral for EchocaRdiogram (REFER) in heart failure: a diagnostic accuracy study

    PubMed Central

    Taylor, Clare J; Roalfe, Andrea K; Iles, Rachel; Hobbs, FD Richard; Barton, P; Deeks, J; McCahon, D; Cowie, MR; Sutton, G; Davis, RC; Mant, J; McDonagh, T; Tait, L

    2017-01-01

    Background Symptoms of breathlessness, fatigue, and ankle swelling are common in general practice but deciding which patients are likely to have heart failure is challenging. Aim To evaluate the performance of a clinical decision rule (CDR), with or without N-Terminal pro-B type natriuretic peptide (NT-proBNP) assay, for identifying heart failure. Design and setting Prospective, observational, diagnostic validation study of patients aged >55 years, presenting with shortness of breath, lethargy, or ankle oedema, from 28 general practices in England. Method The outcome was test performance of the CDR and natriuretic peptide test in determining a diagnosis of heart failure. The reference standard was an expert consensus panel of three cardiologists. Results Three hundred and four participants were recruited, with 104 (34.2%; 95% confidence interval [CI] = 28.9 to 39.8) having a confirmed diagnosis of heart failure. The CDR+NT-proBNP had a sensitivity of 90.4% (95% CI = 83.0 to 95.3) and specificity 45.5% (95% CI = 38.5 to 52.7). NT-proBNP level alone with a cut-off <400 pg/ml had sensitivity 76.9% (95% CI = 67.6 to 84.6) and specificity 91.5% (95% CI = 86.7 to 95.0). At the lower cut-off of NT-proBNP <125 pg/ml, sensitivity was 94.2% (95% CI = 87.9 to 97.9) and specificity 49.0% (95% CI = 41.9 to 56.1). Conclusion At the low threshold of NT-proBNP <125 pg/ml, natriuretic peptide testing alone was better than a validated CDR+NT-proBNP in determining which patients presenting with symptoms went on to have a diagnosis of heart failure. The higher NT-proBNP threshold of 400 pg/ml may mean more than one in five patients with heart failure are not appropriately referred. Guideline natriuretic peptide thresholds may need to be revised. PMID:27919937

  16. Multimission Aircraft Design Study, Payload

    DTIC Science & Technology

    2003-03-01

    number MC2A Multisensor Command and Control Aircraft MC2A-X Multisensor Command and Control Aircraft Experiment MIDS Multifunctional Information and...reconnaissance (ISR) fleet. The MMA is alternately designated as the Multisensor Command and Control Aircraft (MC2A) as indicated in this text. Figure

  17. Decomposing the n-back task: An individual differences study using the reference-back paradigm.

    PubMed

    Rac-Lubashevsky, Rachel; Kessler, Yoav

    2016-09-01

    Working memory (WM) has two major functions: Maintenance, which is the ability to shield information from being overwritten by irrelevant information, and updating, the ability to modify the maintained information when needed. These two conflicting demands are suggested to be controlled by a gating mechanism (for review see O'Reilly (2006)) which enables selective control over updating. Information is robustly maintained in WM when the gate is closed, while opening the gate enables updating. In the present study, we utilized the reference-back paradigm in order to examine their unique contribution to individual differences in n-back, presumably the most widely-used WM updating task. The reference-back is composed of two types of trials: reference trials which require both matching (i.e., a same/different judgment) and WM updating, and comparison trials which require matching and maintenance. Eighty-eight participants performed the following tasks: 2-choice RT, 1-back, 2-back and the reference-back task. A multiple regression approach was taken in order to explain individual differences in 1-back and 2-back. The reference-back task enabled separating the contribution of the matching decision (difference between mismatch and match), gate-opening (the switch cost in reference trials), gate closing (the switch cost in comparison trials) and WM updating (the difference between reference and comparison trials) to task performance. An intrusion component (WM based proactive interference) was also calculated from 2-back performance. The results indicate that RT in 1-back is mainly predicted by gate opening and by WM updating while 2-back is mainly predicted by gate closing and intrusion. These results confirmed that n-back is not merely an updating task, but also that controlling the contents of WM is the main source of individual differences in the task. The implications for understanding the n-back task and WM updating in general are discussed.

  18. Participation in workplace design with reference to low back pain: a case for the improvement of the police patrol car.

    PubMed

    Kuorinka, I; Côté, M M; Baril, R; Geoffrion, R; Giguère, D; Dalzell, M A; Larue, C

    1994-07-01

    Thirty Canadian police officers, divided into six groups, participated in the redesign of the interior of the patrol car. Three of the groups consisted of individuals having a history of low back disease. The effect of participating in a design process on the characteristics of the final design and on the perception of the low back pain was studied in a semi-experimental setting. The participants developed a strong commitment to the participatory design process, which was reflected in their productions. The differences between participants with and without a history of a low back disease was not marked. The former tended to stress posture-related elements in their analysis and design.

  19. Validation of commonly used reference genes for sleep-related gene expression studies

    PubMed Central

    Lee, Kil S; Alvarenga, Tathiana A; Guindalini, Camila; Andersen, Monica L; Castro, Rosa MRPS; Tufik, Sergio

    2009-01-01

    Background Sleep is a restorative process and is essential for maintenance of mental and physical health. In an attempt to understand the complexity of sleep, multidisciplinary strategies, including genetic approaches, have been applied to sleep research. Although quantitative real time PCR has been used in previous sleep-related gene expression studies, proper validation of reference genes is currently lacking. Thus, we examined the effect of total or paradoxical sleep deprivation (TSD or PSD) on the expression stability of the following frequently used reference genes in brain and blood: beta-actin (b-actin), beta-2-microglobulin (B2M), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and hypoxanthine guanine phosphoribosyl transferase (HPRT). Results Neither TSD nor PSD affected the expression stability of all tested genes in both tissues indicating that b-actin, B2M, GAPDH and HPRT are appropriate reference genes for the sleep-related gene expression studies. In order to further verify these results, the relative expression of brain derived neurotrophic factor (BDNF) and glycerol-3-phosphate dehydrogenase1 (GPD1) was evaluated in brain and blood, respectively. The normalization with each of four reference genes produced similar pattern of expression in control and sleep deprived rats, but subtle differences in the magnitude of expression fold change were observed which might affect the statistical significance. Conclusion This study demonstrated that sleep deprivation does not alter the expression stability of commonly used reference genes in brain and blood. Nonetheless, the use of multiple reference genes in quantitative RT-PCR is required for the accurate results. PMID:19445681

  20. Combining cow and bull reference populations to increase accuracy of genomic prediction and genome-wide association studies.

    PubMed

    Calus, M P L; de Haas, Y; Veerkamp, R F

    2013-10-01

    Genomic selection holds the promise to be particularly beneficial for traits that are difficult or expensive to measure, such that access to phenotypes on large daughter groups of bulls is limited. Instead, cow reference populations can be generated, potentially supplemented with existing information from the same or (highly) correlated traits available on bull reference populations. The objective of this study, therefore, was to develop a model to perform genomic predictions and genome-wide association studies based on a combined cow and bull reference data set, with the accuracy of the phenotypes differing between the cow and bull genomic selection reference populations. The developed bivariate Bayesian stochastic search variable selection model allowed for an unbalanced design by imputing residuals in the residual updating scheme for all missing records. The performance of this model is demonstrated on a real data example, where the analyzed trait, being milk fat or protein yield, was either measured only on a cow or a bull reference population, or recorded on both. Our results were that the developed bivariate Bayesian stochastic search variable selection model was able to analyze 2 traits, even though animals had measurements on only 1 of 2 traits. The Bayesian stochastic search variable selection model yielded consistently higher accuracy for fat yield compared with a model without variable selection, both for the univariate and bivariate analyses, whereas the accuracy of both models was very similar for protein yield. The bivariate model identified several additional quantitative trait loci peaks compared with the single-trait models on either trait. In addition, the bivariate models showed a marginal increase in accuracy of genomic predictions for the cow traits (0.01-0.05), although a greater increase in accuracy is expected as the size of the bull population increases. Our results emphasize that the chosen value of priors in Bayesian genomic prediction

  1. Chronic lymphatic leukaemia and engine exhausts, fresh wood, and DDT: a case-referent study.

    PubMed

    Flodin, U; Fredriksson, M; Persson, B; Axelson, O

    1988-01-01

    The effect of potential risk factors for chronic lymphatic leukaemia was evaluated in a case-referent study encompassing 111 cases and 431 randomised referents, all alive. Information on exposure was obtained by questionnaires posted to the subjects. Crude rate ratios were increased for occupational exposure to solvents. DDT, engine exhausts, fresh wood (lumberjacks, paper pulp workers, and sawmill workers, for example) and also in farming. Further analysis of the material by means of the Miettinen confounder score technique reduced the number of rate ratios significantly exceeding unity to encompass only occupational exposure to engine exhaust, fresh wood, DDT, and contact with horses.

  2. Chronic lymphatic leukaemia and engine exhausts, fresh wood, and DDT: a case-referent study.

    PubMed Central

    Flodin, U; Fredriksson, M; Persson, B; Axelson, O

    1988-01-01

    The effect of potential risk factors for chronic lymphatic leukaemia was evaluated in a case-referent study encompassing 111 cases and 431 randomised referents, all alive. Information on exposure was obtained by questionnaires posted to the subjects. Crude rate ratios were increased for occupational exposure to solvents. DDT, engine exhausts, fresh wood (lumberjacks, paper pulp workers, and sawmill workers, for example) and also in farming. Further analysis of the material by means of the Miettinen confounder score technique reduced the number of rate ratios significantly exceeding unity to encompass only occupational exposure to engine exhaust, fresh wood, DDT, and contact with horses. PMID:2449239

  3. PILOT STUDY FOR ESTABLISHMENT OF A NETWORK OF COASTAL REFERENCE SITES

    EPA Science Inventory

    The National Oceanic and Atmospheric Administration (NOAA), U.S. Environmental Protection Agency (EPA), and the National Aeronautics and Space Administration (NASA) have joined in partnership for a pilot study for the establishment of a network of reference sites, the Coastal Int...

  4. Identification of reference genes in human myelomonocytic cells for gene expression studies in altered gravity.

    PubMed

    Thiel, Cora S; Hauschild, Swantje; Tauber, Svantje; Paulsen, Katrin; Raig, Christiane; Raem, Arnold; Biskup, Josefine; Gutewort, Annett; Hürlimann, Eva; Unverdorben, Felix; Buttron, Isabell; Lauber, Beatrice; Philpot, Claudia; Lier, Hartwin; Engelmann, Frank; Layer, Liliana E; Ullrich, Oliver

    2015-01-01

    Gene expression studies are indispensable for investigation and elucidation of molecular mechanisms. For the process of normalization, reference genes ("housekeeping genes") are essential to verify gene expression analysis. Thus, it is assumed that these reference genes demonstrate similar expression levels over all experimental conditions. However, common recommendations about reference genes were established during 1 g conditions and therefore their applicability in studies with altered gravity has not been demonstrated yet. The microarray technology is frequently used to generate expression profiles under defined conditions and to determine the relative difference in expression levels between two or more different states. In our study, we searched for potential reference genes with stable expression during different gravitational conditions (microgravity, normogravity, and hypergravity) which are additionally not altered in different hardware systems. We were able to identify eight genes (ALB, B4GALT6, GAPDH, HMBS, YWHAZ, ABCA5, ABCA9, and ABCC1) which demonstrated no altered gene expression levels in all tested conditions and therefore represent good candidates for the standardization of gene expression studies in altered gravity.

  5. A Survey and Empirical Study of Virtual Reference Service in Academic Libraries

    ERIC Educational Resources Information Center

    Mu, Xiangming; Dimitroff, Alexandra; Jordan, Jeanette; Burclaff, Natalie

    2011-01-01

    Virtual Reference Services (VRS) have high user satisfaction. The main problem is its low usage. We surveyed 100 academic library web sites to understand how VRS are presented. We then conducted a usability study to further test an active VRS model regarding its effectiveness.

  6. A Sixteen Journal Study of Accuracy of Direct Quotes and Associated Reference List Entries.

    ERIC Educational Resources Information Center

    White, Arden; And Others

    A study examined the nature and frequency of faults and errors in reference list entries and direct quotes selected from all 1988 issues of 16 social and biological science journals. All departures from the original (additions, omissions, or changes) were labelled as either a word or punctuation deviation. Of the 402 quotes verified, 33.33%…

  7. The Learning Outcomes of Mentoring Library Science Students in Virtual World Reference: A Case Study

    ERIC Educational Resources Information Center

    Purpur, Geraldine; Morris, Jon Levi

    2015-01-01

    This article reports on the cognitive and affective development of students being mentored in virtual reference interview skills by professional librarians. The authors present a case study which examines the impact on student learning resulting from librarian mentor participation and collaboration with students on a course assignment. This study…

  8. Selection of Reference Genes for Expression Studies of Xenobiotic Adaptation in Tetranychus urticae

    PubMed Central

    Morales, Mariany Ashanty; Mendoza, Bianca Marie; Lavine, Laura Corley; Lavine, Mark Daniel; Walsh, Douglas Bruce; Zhu, Fang

    2016-01-01

    Quantitative real-time PCR (qRT-PCR) is an extensively used, high-throughput method to analyze transcriptional expression of genes of interest. An appropriate normalization strategy with reliable reference genes is required for calculating gene expression across diverse experimental conditions. In this study, we aim to identify the most stable reference genes for expression studies of xenobiotic adaptation in Tetranychus urticae, an extremely polyphagous herbivore causing significant yield reduction of agriculture. We chose eight commonly used housekeeping genes as candidates. The qRT-PCR expression data for these genes were evaluated from seven populations: a susceptible and three acaricide resistant populations feeding on lima beans, and three other susceptible populations which had been shifted host from lima beans to three other plant species. The stability of the candidate reference genes was then assessed using four different algorithms (comparative ΔCt method, geNorm, NormFinder, and BestKeeper). Additionally, we used an online web-based tool (RefFinder) to assign an overall final rank for each candidate gene. Our study found that CycA and Rp49 are best for investigating gene expression in acaricide susceptible and resistant populations. GAPDH, Rp49, and Rpl18 are best for host plant shift studies. And GAPDH and Rp49 were the most stable reference genes when investigating gene expression under changes in both experimental conditions. These results will facilitate research in revealing molecular mechanisms underlying the xenobiotic adaptation of this notorious agricultural pest. PMID:27570487

  9. Reference values for cardiopulmonary exercise testing in healthy volunteers: the SHIP study.

    PubMed

    Koch, B; Schäper, C; Ittermann, T; Spielhagen, T; Dörr, M; Völzke, H; Opitz, C F; Ewert, R; Gläser, S

    2009-02-01

    Cardiopulmonary exercise testing (CPET) is a widely applied clinical procedure. The aim of the present study was to acquire a comprehensive set of reference values for cardiopulmonary responses to exercise and to evaluate possible associations with sex, age and body mass index (BMI). A standardised progressive incremental exercise protocol on a cycle ergometer was applied to 1,708 volunteers of a cross-sectional epidemiologic survey, called "Study of Health in Pomerania". Individuals with cardiopulmonary disorders, or echocardiographic or lung function pathologies, were excluded. The influence of potential confounding factors, such as smoking, taking beta-blockers, hypertension, diastolic dysfunction, BMI and physical activity, were analysed for their influencing power. Reference values of CPET parameters were determined by regression analyses. Of the volunteers, 542 current smokers and obese individuals were excluded for not being representative of a healthy population. The final sample size was 534 (253 males), with age 25-80 yrs. The current study provides a representative set of reference values for CPET parameters based on age and weight. Sex and age have a significant influence on exercise parameters. While addressing the problem of a selection bias, the current study provides the first comprehensive set of reference values obtained in a large number of healthy volunteers within a population-based survey.

  10. Identification of Reference Genes in Human Myelomonocytic Cells for Gene Expression Studies in Altered Gravity

    PubMed Central

    Thiel, Cora S.; Hauschild, Swantje; Tauber, Svantje; Paulsen, Katrin; Raig, Christiane; Raem, Arnold; Biskup, Josefine; Gutewort, Annett; Hürlimann, Eva; Philpot, Claudia; Lier, Hartwin; Engelmann, Frank; Layer, Liliana E.

    2015-01-01

    Gene expression studies are indispensable for investigation and elucidation of molecular mechanisms. For the process of normalization, reference genes (“housekeeping genes”) are essential to verify gene expression analysis. Thus, it is assumed that these reference genes demonstrate similar expression levels over all experimental conditions. However, common recommendations about reference genes were established during 1 g conditions and therefore their applicability in studies with altered gravity has not been demonstrated yet. The microarray technology is frequently used to generate expression profiles under defined conditions and to determine the relative difference in expression levels between two or more different states. In our study, we searched for potential reference genes with stable expression during different gravitational conditions (microgravity, normogravity, and hypergravity) which are additionally not altered in different hardware systems. We were able to identify eight genes (ALB, B4GALT6, GAPDH, HMBS, YWHAZ, ABCA5, ABCA9, and ABCC1) which demonstrated no altered gene expression levels in all tested conditions and therefore represent good candidates for the standardization of gene expression studies in altered gravity. PMID:25654098

  11. Researching Refugee and Forced Migration Studies: An Introduction to the Field and the Reference Literature.

    ERIC Educational Resources Information Center

    Mason, Elisa

    1999-01-01

    Describes the evolution of refugee and forced migration studies, identifies factors that render it a challenging field to research, and highlights a variety of Internet-based and other electronic resources that can be used to locate monographs, periodicals, grey literature, and current information. Provides a bibliography of reference materials in…

  12. Validation of internal reference genes for relative quantitation studies of gene expression in human laryngeal cancer

    PubMed Central

    Wang, Xiaofeng; He, Jinting; Wang, Wei; Ren, Ming; Gao, Sujie; Zhao, Guanjie

    2016-01-01

    Background The aim of this study was to determine the expression stabilities of 12 common internal reference genes for the relative quantitation analysis of target gene expression performed by reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) in human laryngeal cancer. Methods Hep-2 cells and 14 laryngeal cancer tissue samples were investigated. The expression characteristics of 12 internal reference gene candidates (18S rRNA, GAPDH, ACTB, HPRT1, RPL29, HMBS, PPIA, ALAS1, TBP, PUM1, GUSB, and B2M) were assessed by RT-qPCR. The data were analyzed by three commonly used software programs: geNorm, NormFinder, and BestKeeper. Results The use of the combination of four internal reference genes was more appropriate than the use of a single internal reference gene. The optimal combination was PPIA + GUSB + RPL29 + HPRT1 for both the cell line and tissues; while the most appropriate combination was GUSB + RPL29 + HPRT1 + HMBS for the tissues. Conclusions Our recommended internal reference genes may improve the accuracy of relative quantitation analysis of target gene expression performed by the RT-qPCR method in further gene expression research on laryngeal tumors. PMID:27957397

  13. An incident case-referent study of epileptic seizures in adults.

    PubMed

    Forsgren, L; Nyström, L

    1990-01-01

    An epidemiological community-based study of incident cases with non-provoked epileptic seizures, using case-referent methodology, was carried out to explore possible risk factors for epileptic seizures. 83 cases, between 17 and 74 years of age, of whom 67.4% had seizures of localized onset, were compared with 2 age- and sex-matched referents. Higher birth weight, movement disabilities, mental retardation, head trauma, brain tumor, depression, a period of unemployment during the previous 6 months and a history of epilepsy in relatives were more common in cases than in referent subjects. No difference was found in the socioeconomic factors investigated, except that the cases belonged to smaller households. Prematurity, home or hospital birth, parents' age at birth of cases or referents, febrile convulsions in relatives, various infections including meningitis and encephalitis, cerebrovascular disease, and alcohol, tobacco, sleep and nutritional habits were not found to be associated with development of seizures. The recent life events investigated, at home or at work, occurred as often in cases as in referents, except that significantly fewer cases had received any increase in salary during the last 6 months. The relationship between depression and development of seizures should be explored further. Moreover, the possibility of false negative results should be considered because of the sample size.

  14. Submersible Aircraft Concept Design Study

    DTIC Science & Technology

    2010-08-01

    lead to the tips of the wing stalling before the inboard sections, making the aircraft pitch up and potentially stall. In order to combat this, an...the lift being produced by the wing and so reduce hull draft, albeit at the expense of induced drag from the wing . Naval Surface Warfare Center... delta wing design with some blended wing body characteristics was adopted. This approach gives excellent internal volume characteristics whilst

  15. Evaluation of reference genes for gene expression studies in human brown adipose tissue.

    PubMed

    Taube, Magdalena; Andersson-Assarsson, Johanna C; Lindberg, Kristin; Pereira, Maria J; Gäbel, Markus; Svensson, Maria K; Eriksson, Jan W; Svensson, Per-Arne

    2015-01-01

    Human brown adipose tissue (BAT) has during the last 5 year been subjected to an increasing research interest, due to its putative function as a target for future obesity treatments. The most commonly used method for molecular studies of human BAT is the quantitative polymerase chain reaction (qPCR). This method requires normalization to a reference gene (genes with uniform expression under different experimental conditions, e.g. similar expression levels between human BAT and WAT), but so far no evaluation of reference genes for human BAT has been performed. Two different microarray datasets with samples containing human BAT were used to search for genes with low variability in expression levels. Seven genes (FAM96B, GNB1, GNB2, HUWE1, PSMB2, RING1 and TPT1) identified by microarray analysis, and 8 commonly used reference genes (18S, B2M, GAPDH, LRP10, PPIA, RPLP0, UBC, and YWHAZ) were selected and further analyzed by quantitative PCR in both BAT containing perirenal adipose tissue and subcutaneous adipose tissue. Results were analyzed using 2 different algorithms (Normfinder and geNorm). Most of the commonly used reference genes displayed acceptably low variability (geNorm M-values <0.5) in the samples analyzed, but the novel reference genes identified by microarray displayed an even lower variability (M-values <0.25). Our data suggests that PSMB2, GNB2 and GNB1 are suitable novel reference genes for qPCR analysis of human BAT and we recommend that they are included in future gene expression studies of human BAT.

  16. Effects of zero reference position on bladder pressure measurements: an observational study

    PubMed Central

    2012-01-01

    Background Although the World Society for Abdominal Compartment Syndrome in its guidelines recommends midaxillary line (MAL) as zero reference level in intra-abdominal pressure (IAP) measurements in aiming at standardizing the technique, evidence supporting this suggestion is scarce. The aim of this study is to study if the zero reference position influences bladder pressure measurements as estimate for IAP. Methods The IAP of 100 surgical patients was measured during the first 24 h of admission to the surgical intensive care unit of General Calixto Garcia Hospital in Havana (Cuba) following laparotomy. The period was January 2009 to January 2010. The IAP was measured twice with a six-hour interval using the transurethral technique with a priming volume of 25 ml. IAP was first measured with the zero reference level placed at MAL (IAPMAL), followed by a second measurement at the level of the symphysis pubis (SP) after 3 minutes (IAPSP). Correlations were made between IAP and body mass index (BMI), type of surgery, gender, and age. Results Mean IAPMAL was 8.5 ± 2.8 mmHg vs. IAPSP 6.5 ± 2.8 mmHg (p < 0.0001). The bias between measurements was 2.0 ± 1.5, 95% confidence interval of 1.4 to 3.0, upper limit of 4.9, lower limit of -0.9, and a percentage error of 35.1%. IAPMAL was consistently higher than IAPSP regardless of the type of surgery. The BMI correlated with IAP values regardless of the zero reference level (R2 = 0.4 and 0.3 with IAPMAL and IAPSP respectively, p < 0.0001). Conclusions The zero reference level has an important impact on IAP measurement in surgical patients after laparotomy and can potentially lead to over or underestimation. Further anthropometric studies are needed with regard to the relative MAL and SP zero reference position in relation to the theoretical ideal reference level at midpoint of the abdomen. Until better evidence is available, MAL remains the recommended zero reference position due to its best anatomical localization at iliac

  17. Reference values of clinical pathology parameters in cynomolgus monkeys (Macaca fascicularis) used in preclinical studies

    PubMed Central

    Park, Hyun-Kyu; Cho, Jae-Woo; Lee, Byoung-Seok; Park, Heejin; Han, Ji-Seok; Yang, Mi-Jin; Im, Wan-Jung; Park, Do-Yong; Kim, Woo-Jin; Han, Su-Cheol

    2016-01-01

    Nonhuman primates are increasingly used in biomedical research since they are highly homologous to humans compared to other rodent animals. However, there is limited reliable reference data of the clinical pathology parameters in cynomolgus monkeys, and in particular, only some coagulation and urinalysis parameters have been reported. Here, we reported the reference data of clinical chemical, hematological, blood coagulation, and urinalysis parameters in cynomolgus monkeys. The role of sex differences was analyzed and several parameters (including hematocrit, hemoglobin, red blood cell, blood urea nitrogen, total bilirubin, alkaline phosphatase, creatinine kinase, gamma-glutamyl tranferase, and lactate dehydrogenase) significantly differed between male and female subjects. In addition, compared to previous study results, lactate dehydrogenase, creatinine kinase, and aspartate aminotransferase showed significant variation. Interstudy differences could be affected by several factors, including age, sex, geographic origin, presence/absence of anesthetics, fasting state, and the analytical methods used. Therefore, it is important to deliberate with the overall reference indices. In conclusion, the current study provides a comprehensive and updated reference data of the clinical pathology parameters in cynomolgus monkeys and provides improved assessment criteria for evaluating preclinical studies or biomedical research. PMID:27382375

  18. International Linear Collider Reference Design Report Volume 2: Physics at the ILC

    SciTech Connect

    Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; /SLAC /Tokyo U. /Victoria U. /Beijing, Inst. High Energy Phys. /Tel Aviv U. /Birmingham U. /Annecy, LAPP /Minsk, High Energy Phys. Ctr. /DESY /Royal Holloway, U. of London /CERN /Pusan Natl. U. /KEK, Tsukuba /Orsay, LAL /Notre Dame U. /Frascati /Cornell U., Phys. Dept. /Oxford U. /Hefei, CUST /Bangalore, Indian Inst. Sci. /Fermilab

    2011-11-14

    The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic and weak

  19. Design and characterization of an RF excited micro atmospheric pressure plasma jet for reference in plasma medicine

    NASA Astrophysics Data System (ADS)

    Schulz-von der Gathen, Volker

    2015-09-01

    Over the last decade a huge variety of atmospheric pressure plasma jets has been developed and applied for plasma medicine. The efficiency of these non-equilibrium plasmas for biological application is based on the generated amounts of reactive species and radiation. The gas temperatures stay within a range tolerable for temperature-sensitive tissues. The variety of different discharge geometries complicates a direct comparison. In addition, in plasma-medicine the combination of plasma with reactive components, ambient air, as well as biologic tissue - typically also incorporating fluids - results in a complex system. Thus, real progress in plasma-medicine requires a profound knowledge of species, their fluxes and processes hitting biological tissues. That will allow in particular the necessary tailoring of the discharge to fit the conditions. The complexity of the problem can only be overcome by a common effort of many groups and requires a comparison of their results. A reference device based on the already well-investigated micro-scaled atmospheric pressure plasma jet is presented. It is developed in the frame of the European COST initiative MP1101 to establish a publicly available, stable and reproducible source, where required plasma conditions can be investigated. Here we present the design and the ideas behind. The presentation discusses the requirements for the reference source and operation conditions. Biological references are also defined by the initiative. A specific part of the talk will be attributed to the reproducibility of results from various samples of the device. Funding by the DFG within the Package Project PAK816 ``Plasma Cell Interaction in Dermatology'' and the Research Unit FOR 1123 ``Physics of microplasmas'' is gratefully acknowledged.

  20. [Study on temperature measurement of solution by reference-wavelength method].

    PubMed

    Chen, Yun; Liang, Yu-Jie; Chen, Wen-Liang; Xu, Ke-Xin

    2009-10-01

    Near-infrared (NIR) spectroscopy has been widely used in agriculture, medicine, petrochemical and food industries. However, the measurement precision of NIR spectroscopy is adversely affected by the change in external conditions. Among these influence factors, temperature fluctuation is harder to be controlled than other conditions such as contact pressure and measurement position. Based on the displacement effect between solvent and solute molecules in solution, a reference-wavelength method for temperature measurement of solution is presented in the present paper. The theoretical expression of the method was introduced. The experiment was designed to measure the spectra of glucose aqueous solution under different temperatures, and the effect of eliminating the temperature disturbance was evaluated. When the temperature and solute concentration of solution change simultaneously, the absorbency difference value at reference-wavelength is insensitive to solute concentration, and is totally affected by temperature fluctuation. Therefore, according to the absorbance difference, the actual temperature of the sample can be calculated. The regression model of temperature measurement was established, and the solution temperature was calculated based on this model. The information about temperature can be acquired exactly by reference-wavelength method, and the experimental results showed that the average error of calculated temperafure is 0.03 degree C.

  1. Critical Studies in Art and Design Education.

    ERIC Educational Resources Information Center

    Thistlewood, David, Ed.

    This book brings together British and U.S. contributions to the debate of a critical studies approach to art and design education. The approach links practice and appreciation. But critical differences exist in definitions of the term design, with the U.S. recognition of design as the use of principles and elements of art in works and a British…

  2. Design Study for a Mars Geyser Hopper

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Oleson, Steven J.; McGuire, Melissa

    2012-01-01

    The Mars Geyser Hopper is a design reference missions (DRMs) for a Discovery-class spacecraft using Advanced Stirling Radioisotope Generator (ASRG) power source. The Geyser Hopper is a mission concept that will investigate the springtime carbon-dioxide geysers found in regions around the south pole of Mars. The Geyser Hopper design uses Phoenix heritage systems and approach, but uses a single ASRG as the power source, rather than twin solar arrays, and is designed to last over a one-year stay on the South Pole. The spacecraft will land at a target landing area near the south pole of Mars, and have the ability to "hop" after a summertime landing to reposition itself close to a geyser site, and wait through the winter until the first sunlight of spring to witness first-hand the geyser phenomenon.

  3. Recycler ring conceptual design study

    SciTech Connect

    Jackson, G.

    1995-07-18

    The Tevatron Collider provides the highest center of mass energy collisions in the world. To fully exploit this unique tool, Fermilab is committed to a program of accelerator upgrades for the purpose of increasing the Collider luminosity. Over the past 7 years the luminosity has been increased from a peak of 1.6{times}10{sup 30}cm{sup {minus}2}sec{sup {minus}1} in 1989 to over 3{times}10{sup 31}cm{sup {minus}2}sec{sup {minus}1} during 1995. The Main Injector will supply a larger flux of protons for antiproton production and more intense proton bunches for use in the Collider, and this is expected to increase the peak luminosity to close to 1{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}. Further increases in luminosity will require additional upgrades to the Fermilab accelerator complex. This report documents the design of a new fixed-energy storage ring to be placed in the Main Injector tunnel which will provide an initial factor of 2 increase to 2{times}10{sup 32}cm{sup {minus}2}sec{sup {minus}1}, and ultimately provide the basis for an additional order of magnitude luminosity increase up to 1{times}10{sup 33}cm{sup {minus}2}sec{sup {minus}1}.

  4. Defining Top-of-Atmosphere Flux Reference Level for Earth Radiation Budget Studies

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Kato, S.; Wielicki, B. A.

    2002-01-01

    To estimate the earth's radiation budget at the top of the atmosphere (TOA) from satellite-measured radiances, it is necessary to account for the finite geometry of the earth and recognize that the earth is a solid body surrounded by a translucent atmosphere of finite thickness that attenuates solar radiation differently at different heights. As a result, in order to account for all of the reflected solar and emitted thermal radiation from the planet by direct integration of satellite-measured radiances, the measurement viewing geometry must be defined at a reference level well above the earth s surface (e.g., 100 km). This ensures that all radiation contributions, including radiation escaping the planet along slant paths above the earth s tangent point, are accounted for. By using a field-of- view (FOV) reference level that is too low (such as the surface reference level), TOA fluxes for most scene types are systematically underestimated by 1-2 W/sq m. In addition, since TOA flux represents a flow of radiant energy per unit area, and varies with distance from the earth according to the inverse-square law, a reference level is also needed to define satellite-based TOA fluxes. From theoretical radiative transfer calculations using a model that accounts for spherical geometry, the optimal reference level for defining TOA fluxes in radiation budget studies for the earth is estimated to be approximately 20 km. At this reference level, there is no need to explicitly account for horizontal transmission of solar radiation through the atmosphere in the earth radiation budget calculation. In this context, therefore, the 20-km reference level corresponds to the effective radiative top of atmosphere for the planet. Although the optimal flux reference level depends slightly on scene type due to differences in effective transmission of solar radiation with cloud height, the difference in flux caused by neglecting the scene-type dependence is less than 0.1%. If an inappropriate

  5. Interval Management Display Design Study

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Beyer, Timothy M.; Cooke, Stuart D.; Grant, Karlus A.

    2014-01-01

    In 2012, the Federal Aviation Administration (FAA) estimated that U.S. commercial air carriers moved 736.7 million passengers over 822.3 billion revenue-passenger miles. The FAA also forecasts, in that same report, an average annual increase in passenger traffic of 2.2 percent per year for the next 20 years, which approximates to one-and-a-half times the number of today's aircraft operations and passengers by the year 2033. If airspace capacity and throughput remain unchanged, then flight delays will increase, particularly at those airports already operating near or at capacity. Therefore it is critical to create new and improved technologies, communications, and procedures to be used by air traffic controllers and pilots. National Aeronautics and Space Administration (NASA), the FAA, and the aviation industry are working together to improve the efficiency of the National Airspace System and the cost to operate in it in several ways, one of which is through the creation of the Next Generation Air Transportation System (NextGen). NextGen is intended to provide airspace users with more precise information about traffic, routing, and weather, as well as improve the control mechanisms within the air traffic system. NASA's Air Traffic Management Technology Demonstration-1 (ATD-1) Project is designed to contribute to the goals of NextGen, and accomplishes this by integrating three NASA technologies to enable fuel-efficient arrival operations into high-density airports. The three NASA technologies and procedures combined in the ATD-1 concept are advanced arrival scheduling, controller decision support tools, and aircraft avionics to enable multiple time deconflicted and fuel efficient arrival streams in high-density terminal airspace.

  6. An oil flow study of the reference Shuttle-C configuration

    NASA Technical Reports Server (NTRS)

    Pokora, Darlene C.; Springer, Anthony M.

    1994-01-01

    An oil flow study of the reference Shuttle-C configuration is presented. The Shuttle-C vehicle was a proposed shuttle derived vehicle where the orbiter was to be replaced by an unmanned cargo carrier element. Oil flows are shown for the range of Mach numbers from Mach 1.10 to 3.48 at various angles-of-attack and roll angles. The major flow field phenomena over the Shuttle-C reference configuration are shown in these oil flows. Using the oil flows, a qualitative understanding of the flow around the vehicle can be determined, aiding the quantitative definition of aerodynamic data from theoretical analyses and test results. The oil flows presented in this study were obtained from configurations tested in the NASA Marshall Space Flight Center's 14-Inch Trisonic Wind Tunnel from October 1988 through February 1989.

  7. Screening for the Most Suitable Reference Genes for Gene Expression Studies in Equine Milk Somatic Cells.

    PubMed

    Cieslak, Jakub; Mackowski, Mariusz; Czyzak-Runowska, Grazyna; Wojtowski, Jacek; Puppel, Kamila; Kuczynska, Beata; Pawlak, Piotr

    2015-01-01

    Apart from the well-known role of somatic cell count as a parameter reflecting the inflammatory status of the mammary gland, the composition of cells isolated from milk is considered as a valuable material for gene expression studies in mammals. Due to its unique composition, in recent years an increasing interest in mare's milk consumption has been observed. Thus, investigating the genetic background of horse's milk variability presents and interesting study model. Relying on 39 milk samples collected from mares representing three breeds (Polish Primitive Horse, Polish Cold-blooded Horse, Polish Warmblood Horse) we aimed to investigate the utility of equine milk somatic cells as a source of mRNA and to screen the best reference genes for RT-qPCR using geNorm and NormFinder algorithms. The results showed that despite relatively low somatic cell counts in mare's milk, the amount and the quality of the extracted RNA are sufficient for gene expression studies. The analysis of the utility of 7 potential reference genes for RT-qPCR experiments for the normalization of equine milk somatic cells revealed some differences between the outcomes of the applied algorithms, although in both cases the KRT8 and TOP2B genes were pointed as the most stable. Analysis by geNorm showed that the combination of 4 reference genes (ACTB, GAPDH, TOP2B and KRT8) is required for apropriate RT-qPCR experiments normalization, whereas NormFinder algorithm pointed the combination of KRT8 and RPS9 genes as the most suitable. The trial study of the relative transcript abundance of the beta-casein gene with the use of various types and numbers of internal control genes confirmed once again that the selection of proper reference gene combinations is crucial for the final results of each real-time PCR experiment.

  8. A comparative neutron activation analysis study of common generic manipulated and reference medicines commercialized in Brazil.

    PubMed

    Leal, A S; Menezes, M A B C; Rodrigues, R R; Andonie, O; Vermaercke, P; Sneyers, L

    2008-10-01

    In this work, a comparative study of neutron activation analysis (NAA) was performed by the nuclear institutes: CDTN/CNEN-Brazil, CCHEN-Chile and the SCK.CEN-Belgium aiming to investigate some generic, manipulated and reference medicines largely commercialized in Brazil. Some impurities such as: As, Ba, Br, Ce, Co, Cr, Eu, Fe, Hf, Sb, Sc, Sm, Ti and Zn were found, and the heterogeneity of the samples pointed out the lack of an efficient public system of quality control.

  9. How Toddlers and Preschoolers Learn to Uniquely Identify Referents for Others: A Training Study

    ERIC Educational Resources Information Center

    Matthews, Danielle; Lieven, Elena; Tomasello, Michael

    2007-01-01

    This training study investigates how children learn to refer to things unambiguously. Two hundred twenty-four children aged 2.6, 3.6, and 4.6 years were pre- and post-tested for their ability to request stickers from a dense array. Between test sessions, children were assigned to a training condition in which they (a) asked for stickers from an…

  10. Reference tissue modeling with parameter coupling: application to a study of SERT binding in HIV

    NASA Astrophysics Data System (ADS)

    Endres, Christopher J.; Hammoud, Dima A.; Pomper, Martin G.

    2011-04-01

    When applicable, it is generally preferred to evaluate positron emission tomography (PET) studies using a reference tissue-based approach as that avoids the need for invasive arterial blood sampling. However, most reference tissue methods have been shown to have a bias that is dependent on the level of tracer binding, and the variability of parameter estimates may be substantially affected by noise level. In a study of serotonin transporter (SERT) binding in HIV dementia, it was determined that applying parameter coupling to the simplified reference tissue model (SRTM) reduced the variability of parameter estimates and yielded the strongest between-group significant differences in SERT binding. The use of parameter coupling makes the application of SRTM more consistent with conventional blood input models and reduces the total number of fitted parameters, thus should yield more robust parameter estimates. Here, we provide a detailed evaluation of the application of parameter constraint and parameter coupling to [11C]DASB PET studies. Five quantitative methods, including three methods that constrain the reference tissue clearance (kr2) to a common value across regions were applied to the clinical and simulated data to compare measurement of the tracer binding potential (BPND). Compared with standard SRTM, either coupling of kr2 across regions or constraining kr2 to a first-pass estimate improved the sensitivity of SRTM to measuring a significant difference in BPND between patients and controls. Parameter coupling was particularly effective in reducing the variance of parameter estimates, which was less than 50% of the variance obtained with standard SRTM. A linear approach was also improved when constraining kr2 to a first-pass estimate, although the SRTM-based methods yielded stronger significant differences when applied to the clinical study. This work shows that parameter coupling reduces the variance of parameter estimates and may better discriminate between

  11. DROPOUT STUDIES, DESIGN AND CONDUCT.

    ERIC Educational Resources Information Center

    SCHRIEBER, DANIEL; AND OTHERS

    ALTHOUGH THE DROPOUT PROBLEM IS ONE OF GREAT CONCERN AT BOTH LOCAL AND NATIONAL LEVELS, IT IS READILY APPARENT THAT THE PROBLEM IS NOT THE SAME EVERYWHERE IN THE COUNTRY. DROPOUT RATES VARY CONSIDERABLY FROM ONE COMMUNITY TO ANOTHER, AND EVEN DIFFER BETWEEN HIGH SCHOOLS IN THE SAME SCHOOL SYSTEM. LIMITATIONS IN PREVIOUS STUDIES OF THE PROBLEM HAVE…

  12. [Historical cohort study in the German rubber industry: goals, study design and data collection].

    PubMed

    Birk, T; Weiland, S K; Schumann, J; Person, M; Mundt, K; Keil, U

    1995-01-01

    A historical cohort study is carried out to investigate occupational hazards in the German rubber industry since 1991. We present and discuss the study objectives and study design features such as cohort definition, assessment of occupational exposure and selection of the reference population. Cohort enumeration, assessment of vital status and cause of death ascertainment are described. With approximately 2,800 deaths throughout the observation period 1981 to 1991 it will be possible also to study the occupational etiology of rare diseases.

  13. Quarter-scale modeling of room convergence effects on CH (contact-handled) TRU drum waste emplacements using WIPP (Waste Isolation Pilot Plant) reference design geometries

    SciTech Connect

    VandeKraats, J.

    1987-11-01

    This study investigates the effect of horizontal room convergence on CH waste packages emplaced in the WIPP Reference Design geometry (rooms 13 feet high by 33 feet wide, with minus 3/8 inch screened backfill emplaced over and around the waste packages) as a function of time. Based on two tests, predictions were made with regard to full-scale 6-packs emplaced in the Reference Design geometry. These are that load will be transmitted completely through the stack within the first five years after waste emplacement and all drums in all 6-packs will be affected; that virtually all drums will show some deformation eight years after emplacement; that some drums may breach before the eighth year after emplacement has elapsed; and that based on criteria developed during testing, it is predicted that 1% of the drums emplaced will be breached after 8 years and, after 15 years, approximately 12% of the drums are predicted to be breached. 8 refs., 41 figs., 3 tabs.

  14. Initial Piloted Simulation Evaluation of the Reference-H High-Speed Civil Transport Design During Takeoff and Recovery From Limit Flight Conditions

    NASA Technical Reports Server (NTRS)

    Glaab, Louis J.

    1999-01-01

    An initial assessment of a proposed High-Speed Civil Transport (HSCT) was conducted in the fall of 1995 at the NASA Langley Research Center. This configuration, known as the Industry Reference-H (Ref.-H), was designed by the Boeing Aircraft Company as part of their work in the High Speed Research program. It included a conventional tail, a cranked-arrow wing, four mixed-flow turbofan engines, and capacity for transporting approximately 300 passengers. The purpose of this assessment was to evaluate and quantify operational aspects of the Reference-H configuration from a pilot's perspective with the additional goal of identifying design strengths as well as any potential configuration deficiencies. This study was aimed at evaluating the Ref.-H configuration at many points of the aircraft's envelope to determine the suitability of the vehicle to accomplish typical mission profiles as well as emergency or envelope-limit conditions. Pilot-provided Cooper-Harper ratings and comments constituted the primary vehicle evaluation metric. The analysis included simulated real-time piloted evaluations, performed in a 6 degree of freedom motion base NASA Langley Visual-Motion Simulator, combined with extensive bath analysis. The assessment was performed using the third major release of the simulation data base (known as Ref.-H cycle 2B).

  15. On the Science of Education Design Studies.

    ERIC Educational Resources Information Center

    Shavelson, Richard J.; Phillips, D. C.; Towne, Lisa; Feuer, Michael J.

    2003-01-01

    Asserts that design studies, like all scientific work, must comport with guiding scientific principles and provide adequate warrants for their knowledge claims. Provides a framework that links design study research questions as they evolve over time with corresponding research methods, thus allowing an integration of research methods focused on…

  16. Homogeneity study of a corn flour laboratory reference material candidate for inorganic analysis.

    PubMed

    Dos Santos, Ana Maria Pinto; Dos Santos, Liz Oliveira; Brandao, Geovani Cardoso; Leao, Danilo Junqueira; Bernedo, Alfredo Victor Bellido; Lopes, Ricardo Tadeu; Lemos, Valfredo Azevedo

    2015-07-01

    In this work, a homogeneity study of a corn flour reference material candidate for inorganic analysis is presented. Seven kilograms of corn flour were used to prepare the material, which was distributed among 100 bottles. The elements Ca, K, Mg, P, Zn, Cu, Fe, Mn and Mo were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after acid digestion procedure. The method accuracy was confirmed by analyzing the rice flour certified reference material, NIST 1568a. All results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA). In the study, a sample mass of 400mg was established as the minimum mass required for analysis, according to the PCA. The between-bottle test was performed by analyzing 9 bottles of the material. Subsamples of a single bottle were analyzed for the within-bottle test. No significant differences were observed for the results obtained through the application of both statistical methods. This fact demonstrates that the material is homogeneous for use as a laboratory reference material.

  17. Reference Mission Version 3.0 Addendum to the Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team. Addendum; 3.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G. (Editor)

    1998-01-01

    This Addendum to the Mars Reference Mission was developed as a companion document to the NASA Special Publication 6107, "Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team." It summarizes changes and updates to the Mars Reference Missions that were developed by the Exploration Office since the final draft of SP 6107 was printed in early 1999. The Reference Mission is a tool used by the exploration community to compare and evaluate approaches to mission and system concepts that could be used for human missions to Mars. It is intended to identify and clarify system drivers, significant sources of cost, performance, risk, and schedule variation. Several alternative scenarios, employing different technical approaches to solving mission and technology challenges, are discussed in this Addendum. Comparing alternative approaches provides the basis for continual improvement to technology investment plan and a general understanding of future human missions to Mars. The Addendum represents a snapshot of work in progress in support of planning for future human exploration missions through May 1998.

  18. Design study for asteroidal exploitation

    NASA Astrophysics Data System (ADS)

    Adams, Carl; Blissit, Jim; Jarrett, Dave; Sanner, Rob; Yanagawa, Koji

    1985-08-01

    A systematic approach to asteroidal exploitation for the 1990 to 2010 time frame is presented as an initial step toward expanding the use of space beyond the space station by providing a source of lower cost materials. With only a limited amount of information known about the asteroids, reconnaissance and exploration phases to determine the exact locations and compositions of several earth-approaching asteroids are required. Earth-based telescopes are used to locate and study the asteroids, while unmanned probes will return samples of asteroidal material to earth for analysis. After these phases are completed, the retrieval of a 35,000 metric ton piece of the asteroid Anteros is undertaken. A cargo transporter uses magnetoplasmadynamic (MPD) arcjets outbound and a mass-driver using asteroidal material inbound. A crew ship uses ion engines. Low thrust trajectories are used for both spacecraft. A materials processing facility will manufacture propellant pellets and retrieve non-propellant materials for spacecraft use. The cost is 1/10th that to transport the same materials from earth to high earth orbit. The project will cost 25 percent less if done in conjunction with a lunar and Martian base.

  19. Reference genes for gene expression studies in wheat flag leaves grown under different farming conditions

    PubMed Central

    2011-01-01

    Background Internal control genes with highly uniform expression throughout the experimental conditions are required for accurate gene expression analysis as no universal reference genes exists. In this study, the expression stability of 24 candidate genes from Triticum aestivum cv. Cubus flag leaves grown under organic and conventional farming systems was evaluated in two locations in order to select suitable genes that can be used for normalization of real-time quantitative reverse-transcription PCR (RT-qPCR) reactions. The genes were selected among the most common used reference genes as well as genes encoding proteins involved in several metabolic pathways. Findings Individual genes displayed different expression rates across all samples assayed. Applying geNorm, a set of three potential reference genes were suitable for normalization of RT-qPCR reactions in winter wheat flag leaves cv. Cubus: TaFNRII (ferredoxin-NADP(H) oxidoreductase; AJ457980.1), ACT2 (actin 2; TC234027), and rrn26 (a putative homologue to RNA 26S gene; AL827977.1). In addition of these three genes that were also top-ranked by NormFinder, two extra genes: CYP18-2 (Cyclophilin A, AY456122.1) and TaWIN1 (14-3-3 like protein, AB042193) were most consistently stably expressed. Furthermore, we showed that TaFNRII, ACT2, and CYP18-2 are suitable for gene expression normalization in other two winter wheat varieties (Tommi and Centenaire) grown under three treatments (organic, conventional and no nitrogen) and a different environment than the one tested with cv. Cubus. Conclusions This study provides a new set of reference genes which should improve the accuracy of gene expression analyses when using wheat flag leaves as those related to the improvement of nitrogen use efficiency for cereal production. PMID:21951810

  20. Reference Charts for Fetal Cerebellar Vermis Height: A Prospective Cross-Sectional Study of 10605 Fetuses

    PubMed Central

    Cignini, Pietro; Giorlandino, Maurizio; Brutti, Pierpaolo; Mangiafico, Lucia; Aloisi, Alessia; Giorlandino, Claudio

    2016-01-01

    Objective To establish reference charts for fetal cerebellar vermis height in an unselected population. Methods A prospective cross-sectional study between September 2009 and December 2014 was carried out at ALTAMEDICA Fetal–Maternal Medical Centre, Rome, Italy. Of 25203 fetal biometric measurements, 12167 (48%) measurements of the cerebellar vermis were available. After excluding 1562 (12.8%) measurements, a total of 10605 (87.2%) fetuses were considered and analyzed once only. Parametric and nonparametric quantile regression models were used for the statistical analysis. In order to evaluate the robustness of the proposed reference charts regarding various distributional assumptions on the ultrasound measurements at hand, we compared the gestational age-specific reference curves we produced through the statistical methods used. Normal mean height based on parametric and nonparametric methods were defined for each week of gestation and the regression equation expressing the height of the cerebellar vermis as a function of gestational age was calculated. Finally the correlation between dimension/gestation was measured. Results The mean height of the cerebellar vermis was 12.7mm (SD, 1.6mm; 95% confidence interval, 12.7–12.8mm). The regression equation expressing the height of the CV as a function of the gestational age was: height (mm) = -4.85+0.78 x gestational age. The correlation between dimension/gestation was expressed by the coefficient r = 0.87. Conclusion This is the first prospective cross-sectional study on fetal cerebellar vermis biometry with such a large sample size reported in literature. It is a detailed statistical survey and contains new centile-based reference charts for fetal height of cerebellar vermis measurements. PMID:26812238

  1. ACSYNT inner loop flight control design study

    NASA Technical Reports Server (NTRS)

    Bortins, Richard; Sorensen, John A.

    1993-01-01

    The NASA Ames Research Center developed the Aircraft Synthesis (ACSYNT) computer program to synthesize conceptual future aircraft designs and to evaluate critical performance metrics early in the design process before significant resources are committed and cost decisions made. ACSYNT uses steady-state performance metrics, such as aircraft range, payload, and fuel consumption, and static performance metrics, such as the control authority required for the takeoff rotation and for landing with an engine out, to evaluate conceptual aircraft designs. It can also optimize designs with respect to selected criteria and constraints. Many modern aircraft have stability provided by the flight control system rather than by the airframe. This may allow the aircraft designer to increase combat agility, or decrease trim drag, for increased range and payload. This strategy requires concurrent design of the airframe and the flight control system, making trade-offs of performance and dynamics during the earliest stages of design. ACSYNT presently lacks means to implement flight control system designs but research is being done to add methods for predicting rotational degrees of freedom and control effector performance. A software module to compute and analyze the dynamics of the aircraft and to compute feedback gains and analyze closed loop dynamics is required. The data gained from these analyses can then be fed back to the aircraft design process so that the effects of the flight control system and the airframe on aircraft performance can be included as design metrics. This report presents results of a feasibility study and the initial design work to add an inner loop flight control system (ILFCS) design capability to the stability and control module in ACSYNT. The overall objective is to provide a capability for concurrent design of the aircraft and its flight control system, and enable concept designers to improve performance by exploiting the interrelationships between

  2. Odontogenic keratocysts: a clinical and histological study with special reference to enzyme histochemistry.

    PubMed

    Magnusson, B C

    1978-02-01

    Of a total of 1,420 odontogenic cysts, 52 (3.3%) were diagnosed as odontogenic keratocysts. Clinical and histological findings in these 52 cysts are reported. Frozen sections of 26 of the keratocysts were incubated to show the following enzyme activities: NADH2- and NADPH2-diaphorase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, acid phosphatase, leucine aminopeptidase and ATPase. Furthermore, keratinization was studied with the rhodamine B method and lipids with the oil red O, the OTAN and the acid hematein methods. Sections from epidermis, oral mucosa, radicular cysts, residual cysts and follicular cysts served as reference material. The oxidative enzymes showed strong activity in the keratocyst epithelium which contrasted with weak activity in the reference cysts. Acid phosphatase activity was weak in all epithelia except that in keratocysts, which displayed a marked activity. In the fibrous capsule of the keratocyst a high activity of leucine aminopeptidase was recorded. This high activity contrasted with a weak activity in the reference material. The significance of the histochemical results in relation to the aggressive behavior of the keratocyst is discussed.

  3. Small-Angle Neutron Scattering study of the NIST mAb reference material

    NASA Astrophysics Data System (ADS)

    Castellanos, Maria Monica; Liu, Yun; Krueger, Susan; Curtis, Joseph

    Monoclonal antibodies (mAbs) are of great interest to the biopharmaceutical industry because they can be engineered to target specific antigens. Due to their importance, the biomanufacturing initiative at NIST is developing an IgG1 mAb reference material `NIST mAb', which can be used by industry, academia, and regulatory authorities. As part of this collaborative effort, we aim at characterizing the reference material using neutron scattering techniques. We have studied the small-angle scattering profile of the NIST mAb in a histidine buffer at 0 and 150 mM NaCl. Using Monte Carlo simulations, we generate an ensemble of structures and calculate their theoretical scattering profile, which can be directly compared with experimental data. Moreover, we analyze the structure factor to understand the effect of solution conditions on the protein-protein interactions. Finally, we have measured the solution scattering of the NIST mAb, while simultaneously performing freeze/thaw cycles, in order to investigate if the solution structure was affected upon freezing. The results from neutron scattering not only support the development of the reference material, but also provide insights on its stability and guide efforts for its development under different formulations.

  4. Preliminary design study of lunar housing configurations

    NASA Technical Reports Server (NTRS)

    Reynolds, K. H.

    1992-01-01

    A preliminary design study assesses various configurations for habitation of the lunar surface. The study assumes an initial 4-man habitation module expandable to a 48-man concept. Through the numerous coupling combinations of identical modules, five basic configuration types are identified. A design model presents each configuration in light of certain issues. The issues include circulation, internal and external spatial characteristics, functional organizations, and future growth potential. The study discusses the attributes, potentials, and unique requirements of each configuration.

  5. Design of Linear DC Motor Two-degree-of-freedom Positioning System using Model Reference type Sliding Mode Controller

    NASA Astrophysics Data System (ADS)

    Urushihara, Shiro; Kamano, Takuya; Yura, Satoshi; Yasuno, Takashi; Suzuki, Takayuki

    One of fundamental problems in the factory automation is how to obtain linear motion. Linear motors produce directly the linear motion force without a motion-transform mechanism. Linear d.c. motors (LDMs) have excellent performance and controllability. However, the dynamics of small-sized LDMs is adversely affected by the dead-band due to the friction between brushes and commutators. In this paper, it is described that the design of the two-degree-of-freedom positioning system with a LDM using model reference type sliding mode controller (SMC). The proposed positioning system consists of a fixed gain feedforward controller and a SMC used as a feedback controller. The objective of the SMC is to repress the influence of nonlinear characteristics (the dead-band and parameter variations etc.). The tracking performance can be improved as the fixed gain feedforward controller makes a dynamic inverse system in the feedforward path. The effectiveness of the proposed system for improvement of the tracking performance is demonstrated by experimental results.

  6. Mirror Advanced Reactor Study interim design report

    SciTech Connect

    Not Available

    1983-04-01

    The status of the design of a tenth-of-a-kind commercial tandem-mirror fusion reactor is described at the midpoint of a two-year study. When completed, the design is to serve as a strategic goal for the mirror fusion program. The main objectives of the Mirror Advanced Reactor Study (MARS) are: (1) to design an attractive tandem-mirror fusion reactor producing electricity and synfuels (in alternate versions), (2) to identify key development and technology needs, and (3) to exploit the potential of fusion for safety, low activation, and simple disposal of radioactive waste. In the first year we have emphasized physics and engineering of the central cell and physics of the end cell. Design optimization and trade studies are continuing, and we expect additional modifications in the end cells to further improve the performance of the final design.

  7. Cost studies for commercial fuselage crown designs

    NASA Technical Reports Server (NTRS)

    Walker, T. H.; Smith, P. J.; Truslove, G.; Willden, K. S.; Metschan, S. L.; Pfahl, C. L.

    1991-01-01

    Studies were conducted to evaluate the cost and weight potential of advanced composite design concepts in the crown region of a commercial transport. Two designs from each of three design families were developed using an integrated design-build team. A range of design concepts and manufacturing processes were included to allow isolation and comparison of cost centers. Detailed manufacturing/assembly plans were developed as the basis for cost estimates. Each of the six designs was found to have advantages over the 1995 aluminum benchmark in cost and weight trade studies. Large quadrant panels and cobonded frames were found to save significant assembly labor costs. Comparisons of high- and intermediate-performance fiber systems were made for skin and stringer applications. Advanced tow placement was found to be an efficient process for skin lay up. Further analysis revealed attractive processes for stringers and frames. Optimized designs were informally developed for each design family, combining the most attractive concepts and processes within that family. A single optimized design was selected as the most promising, and the potential for further optimization was estimated. Technical issues and barriers were identified.

  8. Optimal Reference Strain Structure for Studying Dynamic Responses of Flexible Rockets

    NASA Technical Reports Server (NTRS)

    Tsushima, Natsuki; Su, Weihua; Wolf, Michael G.; Griffin, Edwin D.; Dumoulin, Marie P.

    2017-01-01

    In the proposed paper, the optimal design of reference strain structures (RSS) will be performed targeting for the accurate observation of the dynamic bending and torsion deformation of a flexible rocket. It will provide the detailed description of the finite-element (FE) model of a notional flexible rocket created in MSC.Patran. The RSS will be attached longitudinally along the side of the rocket and to track the deformation of the thin-walled structure under external loads. An integrated surrogate-based multi-objective optimization approach will be developed to find the optimal design of the RSS using the FE model. The Kriging method will be used to construct the surrogate model. For the data sampling and the performance evaluation, static/transient analyses will be performed with MSC.Natran/Patran. The multi-objective optimization will be solved with NSGA-II to minimize the difference between the strains of the launch vehicle and RSS. Finally, the performance of the optimal RSS will be evaluated by checking its strain-tracking capability in different numerical simulations of the flexible rocket.

  9. New SCALE Sensitivity/Uncertainty Capabilities Applied to Bias Estimation and to Design of MIRTE Reference Experiments

    SciTech Connect

    Rearden, Bradley T; Duhamel, Isabelle; Letang, Eric

    2009-01-01

    New TSUNAMI tools of SCALE 6, TSURFER and TSAR, are demonstrated to examine the bias effects of small-worth test materials, relative to reference experiments. TSURFER is a data adjustment bias and bias uncertainty assessment tool, and TSAR computes the sensitivity of the change in reactivity between two systems to the cross-section data common to their calculation. With TSURFER, it is possible to examine biases and bias uncertainties in fine detail. For replacement experiments, the application of TSAR to TSUNAMI-3D sensitivity data for pairs of experiments allows the isolation of sources of bias that could otherwise be obscured by materials with more worth in an individual experiment. The application of TSUNAMI techniques in the design of nine reference experiments for the MIRTE program will allow application of these advanced techniques to data acquired in the experimental series. The validation of all materials in a complex criticality safety application likely requires consolidating information from many different critical experiments. For certain materials, such as structural materials or fission products, only a limited number of critical experiments are available, and the fuel and moderator compositions of the experiments may differ significantly from those of the application. In these cases, it is desirable to extract the computational bias of a specific material from an integral keff measurement and use that information to quantify the bias due to the use of the same material in the application system. Traditional parametric and nonparametric methods are likely to prove poorly suited for such a consolidation of specific data components from a diverse set of experiments. An alternative choice for consolidating specific data from numerous sources is a data adjustment tool, like the ORNL tool TSURFER (Tool for Sensitivity/Uncertainty analysis of Response Functionals using Experimental Results) from SCALE 6.1 However, even with TSURFER, it may be difficult to

  10. The Reference Ability Neural Network Study: Life-time stability of reference-ability neural networks derived from task maps of young adults.

    PubMed

    Habeck, C; Gazes, Y; Razlighi, Q; Steffener, J; Brickman, A; Barulli, D; Salthouse, T; Stern, Y

    2016-01-15

    Analyses of large test batteries administered to individuals ranging from young to old have consistently yielded a set of latent variables representing reference abilities (RAs) that capture the majority of the variance in age-related cognitive change: Episodic Memory, Fluid Reasoning, Perceptual Processing Speed, and Vocabulary. In a previous paper (Stern et al., 2014), we introduced the Reference Ability Neural Network Study, which administers 12 cognitive neuroimaging tasks (3 for each RA) to healthy adults age 20-80 in order to derive unique neural networks underlying these 4 RAs and investigate how these networks may be affected by aging. We used a multivariate approach, linear indicator regression, to derive a unique covariance pattern or Reference Ability Neural Network (RANN) for each of the 4 RAs. The RANNs were derived from the neural task data of 64 younger adults of age 30 and below. We then prospectively applied the RANNs to fMRI data from the remaining sample of 227 adults of age 31 and above in order to classify each subject-task map into one of the 4 possible reference domains. Overall classification accuracy across subjects in the sample age 31 and above was 0.80±0.18. Classification accuracy by RA domain was also good, but variable; memory: 0.72±0.32; reasoning: 0.75±0.35; speed: 0.79±0.31; vocabulary: 0.94±0.16. Classification accuracy was not associated with cross-sectional age, suggesting that these networks, and their specificity to the respective reference domain, might remain intact throughout the age range. Higher mean brain volume was correlated with increased overall classification accuracy; better overall performance on the tasks in the scanner was also associated with classification accuracy. For the RANN network scores, we observed for each RANN that a higher score was associated with a higher corresponding classification accuracy for that reference ability. Despite the absence of behavioral performance information in the

  11. Protocol and standard operating procedures for common use in a worldwide multicenter study on reference values.

    PubMed

    Ozarda, Yesim; Ichihara, Kiyoshi; Barth, Julian H; Klee, George

    2013-05-01

    The reference intervals (RIs) given in laboratory reports have an important role in aiding clinicians in interpreting test results in reference to values of healthy populations. In this report, we present a proposed protocol and standard operating procedures (SOPs) for common use in conducting multicenter RI studies on a national or international scale. The protocols and consensus on their contents were refined through discussions in recent C-RIDL meetings. The protocol describes in detail (1) the scheme and organization of the study, (2) the target population, inclusion/exclusion criteria, ethnicity, and sample size, (3) health status questionnaire, (4) target analytes, (5) blood collection, (6) sample processing and storage, (7) assays, (8) cross-check testing, (9) ethics, (10) data analyses, and (11) reporting of results. In addition, the protocol proposes the common measurement of a panel of sera when no standard materials exist for harmonization of test results. It also describes the requirements of the central laboratory, including the method of cross-check testing between the central laboratory of each country and local laboratories. This protocol and the SOPs remain largely exploratory and may require a reevaluation from the practical point of view after their implementation in the ongoing worldwide study. The paper is mainly intended to be a basis for discussion in the scientific community.

  12. Reference Ranges for Uterine Artery Pulsatility Index during the Menstrual Cycle: A Cross-Sectional Study

    PubMed Central

    Guedes-Martins, Luís; Gaio, Rita; Saraiva, Joaquim; Cerdeira, Sofia; Matos, Liliana; Silva, Elisabete; Macedo, Filipe; Almeida, Henrique

    2015-01-01

    Background Cyclic endometrial neoangiogenesis contributes to changes in local vascular patterns and is amenable to non-invasive assessment with Doppler sonography. We hypothesize that the uterine artery (UtA) impedance, measured by its pulsatility index (PI), exhibits a regular pattern during the normal menstrual cycle. Therefore, the main study objective was to derive normative new day-cycle-based reference ranges for the UtA-PI during the entire cycle from days 1 to 34 according to the isolated time effect and potential confounders such as age and parity. Methods From January 2009 to December 2012, a cross-sectional study of 1,821 healthy women undergoing routine gynaecological ultrasound was performed. The Doppler flow of the right and left UtA-PI was studied transvaginally by colour and pulsed Doppler imaging. The mean right and left values and the presence or absence of a bilateral protodiastolic notch were recorded. Reference intervals for the PI according to the cycle day were generated by classical linear regression. Results The majority of patients (97.5%) presented unilateral or bilateral UtA notches. The crude 5th, 50th, and 95th reference percentile curves of the UtA-PI at 1–34 days of the normal menstrual cycle were derived. In all curves, a progressive significant decrease occurred during the first 13 days, followed by an increase and recovery in the UtA-PI. The adjusted 5th, 50th, and 95th reference percentile curves for the effects of age and parity were also obtained. These two conditions generated an approximately identical UtA-PI pattern during the cycle, except with small but significant reductions at the temporal extremes. Conclusions The median, 5th, and the 95th percentiles of the UtA-PI decrease during the first third of the menstrual cycle and recover to their initial values during the last two thirds of the cycle. The rates of decrease and recovery depend significantly on age and parity. PMID:25742286

  13. Sequential design approaches for bioequivalence studies with crossover designs.

    PubMed

    Potvin, Diane; DiLiberti, Charles E; Hauck, Walter W; Parr, Alan F; Schuirmann, Donald J; Smith, Robert A

    2008-01-01

    The planning of bioequivalence (BE) studies, as for any clinical trial, requires a priori specification of an effect size for the determination of power and an assumption about the variance. The specified effect size may be overly optimistic, leading to an underpowered study. The assumed variance can be either too small or too large, leading, respectively, to studies that are underpowered or overly large. There has been much work in the clinical trials field on various types of sequential designs that include sample size reestimation after the trial is started, but these have seen only little use in BE studies. The purpose of this work was to validate at least one such method for crossover design BE studies. Specifically, we considered sample size reestimation for a two-stage trial based on the variance estimated from the first stage. We identified two methods based on Pocock's method for group sequential trials that met our requirement for at most negligible increase in type I error rate.

  14. Selection of reference genes for quantitative RT-PCR studies in striped dolphin (Stenella coeruleoalba) skin biopsies

    PubMed Central

    Spinsanti, Giacomo; Panti, Cristina; Lazzeri, Elisa; Marsili, Letizia; Casini, Silvia; Frati, Francesco; Fossi, Cristina Maria

    2006-01-01

    Background Odontocete cetaceans occupy the top position of the marine food-web and are particularly sensitive to the bioaccumulation of lipophilic contaminants. The effects of environmental pollution on these species are highly debated and various ecotoxicological studies have addressed the impact of xenobiotic compounds on marine mammals, raising conservational concerns. Despite its sensitivity, quantitative real-time PCR (qRT-PCR) has never been used to quantify gene induction caused by exposure of cetaceans to contaminants. A limitation for the application of qRT-PCR is the need for appropriate reference genes which allow the correct quantification of gene expression. A systematic evaluation of potential reference genes in cetacean skin biopsies is presented, in order to validate future qRT-PCR studies aiming at using the expression of selected genes as non-lethal biomarkers. Results Ten commonly used housekeeping genes (HKGs) were partially sequenced in the striped dolphin (Stenella coeruleoalba) and, for each gene, PCR primer pairs were specifically designed and tested in qRT-PCR assays. The expression of these potential control genes was examined in 30 striped dolphin skin biopsy samples, obtained from specimens sampled in the north-western Mediterranean Sea. The stability of selected control genes was determined using three different specific VBA applets (geNorm, NormFinder and BestKeeper) which produce highly comparable results. Glyceraldehyde-3P-dehydrogenase (GAPDH) and tyrosine 3-monooxygenase (YWHAZ) always rank as the two most stably expressed HKGs according to the analysis with geNorm and Normfinder, and are defined as optimal control genes by BestKepeer. Ribosomal protein L4 (RPL4) and S18 (RPS18) also exhibit a remarkable stability of their expression levels. On the other hand, transferrin receptor (TFRC), phosphoglycerate kinase 1 (PGK1), hypoxanthine ribosyltransferase (HPRT1) and β-2-microglobin (B2M) show variable expression among the studied

  15. Measurement of human energy expenditure, with particular reference to field studies: an historical perspective.

    PubMed

    Shephard, Roy J; Aoyagi, Yukitoshi

    2012-08-01

    Over the years, techniques for the study of human movement have ranged in complexity and precision from direct observation of the subject through activity diaries, questionnaires, and recordings of body movement, to the measurement of physiological responses, studies of metabolism and indirect and direct calorimetry. This article reviews developments in each of these domains. Particular reference is made to their impact upon the continuing search for valid field estimates of activity patterns and energy expenditures, as required by the applied physiologist, ergonomist, sports scientist, nutritionist and epidemiologist. Early observers sought to improve productivity in demanding employment. Direct observation and filming of workers were supplemented by monitoring of heart rates, ventilation and oxygen consumption. Such methods still find application in ergonomics and sport, but many investigators are now interested in relationships between habitual physical activity and chronic disease. Even sophisticated questionnaires still do not provide valid information on the absolute energy expenditures associated with good health. Emphasis has thus shifted to use of sophisticated pedometer/accelerometers, sometimes combining their output with GPS and other data. Some modern pedometer/accelerometers perform well in the laboratory, but show substantial systematic errors relative to laboratory reference criteria such as the metabolism of doubly labeled water when assessing the varied activities of daily life. The challenge remains to develop activity monitors that are sufficiently inexpensive for field use, yet meet required accuracy standards. Possibly, measurements of oxygen consumption by portable respirometers may soon satisfy part of this need, although a need for valid longer term monitoring will remain.

  16. Selection of reference genes for gene expression studies in zucchini (Cucurbita pepo) using qPCR.

    PubMed

    Obrero, Angeles; Die, Jose V; Román, Belén; Gómez, Pedro; Nadal, Salvador; González-Verdejo, Clara I

    2011-05-25

    The zucchini (Cucurbita pepo) is an important food crop, the transcriptomics of which are a fundamental tool to accelerate the development of new varieties by breeders. However, the suitability of reference genes for data normalization in zucchini has not yet been studied. The aim of this study was to assess the suitability of 13 genes for their potential use as reference genes in quantitative real-time PCR. Assays were performed on 34 cDNA samples representing plants under different stresses and at different developmental stages. The application of geNorm and NormFinder software revealed that the use of a combination of UFP, EF-1A, RPL36aA, PP2A, and CAC genes for the different experimental sets was the best strategy for reliable normalization. In contrast, 18S rRNA and TUA were less stable and unsuitable for use as internal controls. These results provide the possibility to allow more accurate use of qPCR in this horticultural crop.

  17. Lower Columbia River and Estuary Ecosystem Restoration Program Reference Site Study: 2011 Restoration Analysis - FINAL REPORT

    SciTech Connect

    Borde, Amy B.; Cullinan, Valerie I.; Diefenderfer, Heida L.; Thom, Ronald M.; Kaufmann, Ronald M.; Zimmerman, Shon A.; Sagar, Jina; Buenau, Kate E.; Corbett, C.

    2012-05-31

    The Reference Site (RS) study is part of the research, monitoring, and evaluation (RME) effort developed by the Action Agencies (Bonneville Power Administration [BPA], U.S. Army Corps of Engineers, Portland District [USACE], and U.S. Bureau of Reclamation) in response to Federal Columbia River Power System (FCRPS) Biological Opinions (BiOp). While the RS study was initiated in 2007, data have been collected at relatively undisturbed reference wetland sites in the LCRE by PNNL and collaborators since 2005. These data on habitat structural metrics were previously summarized to provide baseline characterization of 51 wetlands throughout the estuarine and tidal freshwater portions of the 235-km LCRE; however, further analysis of these data has been limited. Therefore, in 2011, we conducted additional analyses of existing field data previously collected for the Columbia Estuary Ecosystem Restoration Program (CEERP) - including data collected by PNNL and others - to help inform the multi-agency restoration planning and ecosystem management work underway in the LCRE.

  18. Nanomaterials for environmental studies: classification, reference material issues, and strategies for physico-chemical characterisation.

    PubMed

    Stone, Vicki; Nowack, Bernd; Baun, Anders; van den Brink, Nico; Kammer, Frank von der; Dusinska, Maria; Handy, Richard; Hankin, Steven; Hassellöv, Martin; Joner, Erik; Fernandes, Teresa F

    2010-03-01

    NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions: 1. What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies? 2. What reference materials should be developed for use in environmental and ecotoxicological studies? 3. Is it possible to group different nanomaterials into categories for consideration in environmental studies? Such questions have been, at least partially, addressed by other projects/workshops especially in relation to human health effects. Such projects provide a useful basis on which this workshop was based, but in this particular case these questions were reformulated in order to focus specifically on environmental studies. The workshop participants, through a series of discussion and reflection sessions, generated the conclusions listed below. The physicochemical characterisation information identified as important for environmental studies included measures of aggregation/agglomeration/dispersability, size, dissolution (solubility), surface area, surface charge, surface chemistry/composition, with the assumption that chemical composition would already be known. There is a need to have test materials for ecotoxicology, and several substances are potentially useful, including TiO(2) nanoparticles, polystyrene beads labelled with fluorescent dyes, and silver nanoparticles. Some of these test materials could then be developed into certified reference materials over time. No clear consensus was reached regarding the classification of nanomaterials into categories to aid environmental studies, except that a chemistry-based classification system was a reasonable starting point, with some modifications. It was suggested, that additional work may be

  19. Design optimization studies using COSMIC NASTRAN

    NASA Technical Reports Server (NTRS)

    Pitrof, Stephen M.; Bharatram, G.; Venkayya, Vipperla B.

    1993-01-01

    The purpose of this study is to create, test and document a procedure to integrate mathematical optimization algorithms with COSMIC NASTRAN. This procedure is very important to structural design engineers who wish to capitalize on optimization methods to ensure that their design is optimized for its intended application. The OPTNAST computer program was created to link NASTRAN and design optimization codes into one package. This implementation was tested using two truss structure models and optimizing their designs for minimum weight, subject to multiple loading conditions and displacement and stress constraints. However, the process is generalized so that an engineer could design other types of elements by adding to or modifying some parts of the code.

  20. Validation of reference genes for RT-qPCR studies of gene expression in banana fruit under different experimental conditions.

    PubMed

    Chen, Lei; Zhong, Hai-ying; Kuang, Jian-fei; Li, Jian-guo; Lu, Wang-jin; Chen, Jian-ye

    2011-08-01

    Reverse transcription quantitative real-time PCR (RT-qPCR) is a sensitive technique for quantifying gene expression, but its success depends on the stability of the reference gene(s) used for data normalization. Only a few studies on validation of reference genes have been conducted in fruit trees and none in banana yet. In the present work, 20 candidate reference genes were selected, and their expression stability in 144 banana samples were evaluated and analyzed using two algorithms, geNorm and NormFinder. The samples consisted of eight sample sets collected under different experimental conditions, including various tissues, developmental stages, postharvest ripening, stresses (chilling, high temperature, and pathogen), and hormone treatments. Our results showed that different suitable reference gene(s) or combination of reference genes for normalization should be selected depending on the experimental conditions. The RPS2 and UBQ2 genes were validated as the most suitable reference genes across all tested samples. More importantly, our data further showed that the widely used reference genes, ACT and GAPDH, were not the most suitable reference genes in many banana sample sets. In addition, the expression of MaEBF1, a gene of interest that plays an important role in regulating fruit ripening, under different experimental conditions was used to further confirm the validated reference genes. Taken together, our results provide guidelines for reference gene(s) selection under different experimental conditions and a foundation for more accurate and widespread use of RT-qPCR in banana.

  1. Design Considerations for Artificial Pancreas Pivotal Studies.

    PubMed

    Russell, Steven J; Beck, Roy W

    2016-07-01

    The development of artificial pancreas systems has evolved to the point that pivotal studies designed to assess efficacy and safety are in progress or soon to be initiated. These pivotal studies are intended to provide the necessary data to gain clearance from the U.S. Food and Drug Administration, coverage by payers, and adoption by patients and clinicians. Although there will not be one design that is appropriate for every system, there are certain aspects of protocol design that will be considerations in all pivotal studies designed to assess efficacy and safety. One key aspect of study design is the intervention to be used by the control group. A case can be made that the control group should use the currently available best technology, which is sensor-augmented pump therapy. However, an equally, if not more, compelling case can be made that the control intervention should be usual care. In this Perspective, we elaborate on this issue and provide a pragmatic approach to the design of clinical trials of artificial pancreas systems.

  2. Selection of Reference Genes for Gene Expression Studies related to lung injury in a preterm lamb model

    PubMed Central

    Pereira-Fantini, Prue M.; Rajapaksa, Anushi E.; Oakley, Regina; Tingay, David G.

    2016-01-01

    Preterm newborns often require invasive support, however even brief periods of supported ventilation applied inappropriately to the lung can cause injury. Real-time quantitative reverse transcriptase-PCR (qPCR) has been extensively employed in studies of ventilation-induced lung injury with the reference gene 18S ribosomal RNA (18S RNA) most commonly employed as the internal control reference gene. Whilst the results of these studies depend on the stability of the reference gene employed, the use of 18S RNA has not been validated. In this study the expression profile of five candidate reference genes (18S RNA, ACTB, GAPDH, TOP1 and RPS29) in two geographical locations, was evaluated by dedicated algorithms, including geNorm, Normfinder, Bestkeeper and ΔCt method and the overall stability of these candidate genes determined (RefFinder). Secondary studies examined the influence of reference gene choice on the relative expression of two well-validated lung injury markers; EGR1 and IL1B. In the setting of the preterm lamb model of lung injury, RPS29 reference gene expression was influenced by tissue location; however we determined that individual ventilation strategies influence reference gene stability. Whilst 18S RNA is the most commonly employed reference gene in preterm lamb lung studies, our results suggest that GAPDH is a more suitable candidate. PMID:27210246

  3. Engineering study for ISSTRS design concept

    SciTech Connect

    Hertzel, J.S.

    1997-01-31

    Los Alamos Technical Associates, Inc., is pleased to transmit the attached Conceptual Design Package for the Initial Single Shell Tank Retrieval System (ISSTRS), 90% Conceptual Design Review. The package includes the following: (1) ISSTRS Trade Studies: (a) Retrieval Facility Cooling Requirements; (b) Equipment Re-usability between Project W-320 and Tanks 241-C-103 and 241-C-1 05; (c) Sluice Line Options; and (d) Options for the Location of Tanks AX-103 and A-1 02 HVAC Equipment; (2) Drawings; (3) Risk Management Plan; (4) 0850 Interface Control Document; (5) Requirements Traceability Report; and (6) Project Design Specification.

  4. Carpal tunnel syndrome (CTS) and exposure to vibration, repetitive wrist movements, and heavy manual work: a case-referent study.

    PubMed Central

    Wieslander, G; Norbäck, D; Göthe, C J; Juhlin, L

    1989-01-01

    Possible connections between carpal tunnel syndrome (CTS) and exposure to vibrating handheld tools, repetitive wrist movements, and heavy manual work were examined in a case-referent study. The cases were 38 men operated on for CTS between 1974 and 1980. For each case, two referents were drawn from among other surgical cases (hospital referents) and two further referents from the population register and telephone directory, respectively (population referents). Thirty four of 38 cases (89%) and 143 of 152 referents (94%) were interviewed by telephone. An increased prevalence of obesity, rheumatoid disease, diabetes, or thyroid disease was observed among the cases but most did not suffer from any of these disorders. CTS was significantly correlated with exposure to vibration from handheld tools and to repetitive wrist movements but showed a weaker correlation with work producing a heavy load on the wrist. A cause-effect relation between CTS and exposures to handheld vibrating tools and to work causing repetitive movements of the wrist seems probable. Some differences between hospital and population referents indicate that a case-referent study of this type could be biased by inappropriate selection of referents. PMID:2920142

  5. Eliminating traditional reference services in an academic health sciences library: a case study

    PubMed Central

    Schulte, Stephanie J

    2011-01-01

    Question: How were traditional librarian reference desk services successfully eliminated at one health sciences library? Setting: The analysis was done at an academic health sciences library at a major research university. Method: A gap analysis was performed, evaluating changes in the first eleven months through analysis of reference transaction and instructional session data. Main Results: Substantial increases were seen in the overall number of specialized reference transactions and those conducted by librarians lasting more than thirty minutes. The number of reference transactions overall increased after implementing the new model. Several new small-scale instructional initiatives began, though perhaps not directly related to the new model. Conclusion: Traditional reference desk services were eliminated at one academic health sciences library without negative impact on reference and instructional statistics. Eliminating ties to the confines of the physical library due to staffing reference desk hours removed one significant barrier to a more proactive liaison program. PMID:22022221

  6. Design Study of Small Efficient Cryocoolers.

    DTIC Science & Technology

    1980-11-01

    I~ V 1k I HL I 1 o’i AL A19 9 0 8 (92 DESIGN STUDY OF SMALL EFFICIENT CRYOCOOLERS PHILIPS LABORATORIES A Division of North American Philips...REPORT A PERIOD COVERED Final Technical Report DESIGN SJDY OF SMALL EFFICIENT CRYOCOOLERS April 14 - Sept. 11, 1980 6. PERFORMING ORG. REPORT NUMBER 7... Stirling cycle refrigerator linear motor cryogenic refrigerator for 100K triple-expansion Stirling -cycle refrigerator free-displacer, free-piston

  7. Case-referent study of lung tumors in non-asbestos textile workers

    SciTech Connect

    Paci, E.; Buiatti, E.; Geddes, M.

    1987-01-01

    A case series in the Province of Florence showed an increased risk of mesothelioma in textile workers (nonasbestos) and a survey of working conditions confirmed potential exposure to asbestos. In order to investigate the risk in textile workers, including some specific job titles, a case-referent study on lung tumors was carried out. The lung cancer cases included 441 males with histologically confirmed primary lung cancer during the period 1980-1983. Referents included 1,075 males selected from two hospitals and matched for age, sex, and smoking habits. Those who had ''ever worked'' in the textile industry showed an adjusted odds ratio of 1.52 (95% C.I. 1-2.25) compared with other ''industrial workers.'' This moderately increased risk is maintained in selected jobs in the textile industry. An analysis of the modifying effect of time factors showed an increased risk in the period of 15-35 years from the date of first employment in the industry. The results support the hypothesis that a probable risk of lung cancer in textile workers in the Prato area was related to asbestos exposure.

  8. Reference values for ethylenethiourea in urine in Northern Italy: results of a pilot study.

    PubMed

    Colosio, Claudio; Visentin, Sara; Birindelli, Sarah; Campo, Laura; Fustinoni, Silvia; Mariani, Franco; Tiramani, Manuela; Tommasini, Michele; Brambilla, Gabri; Maroni, Marco

    2006-04-10

    This study was carried out to define reference values for urinary ethylenethiourea (ETU) in the Northern Italy population and to identify the sources of exposure. Ninety-five healthy subjects were selected. A spot urine sample was collected in the morning, and analyzed using GC/MS in the EI/SIM mode. Thirty-nine subjects showed urinary ETU concentrations lower than the limit of detection (LOD, 0.4 microg/g creatinine), and the remainders ETU concentrations ranging from 0.5 to 11.6 microg/g creatinine. No correlation was shown between smoke or alcohol intake and urinary ETU concentrations. Based on data on ethylene-bis-dithiocarbamate (EBDC) concentrations in food, we estimated a total EBDCs intake of 31.7-50.1 microg/day. These values are largely below the ADIs, but explain the presence of small amounts of ETU in the urine samples we have analyzed. Finally, it was estimated that the mean ETU in urine in the Italian general population is 0.6-0.8 microg/g creatinine, with a 95th percentile of 4.5-5.0 microg/g creatinine. These values can be used as reference, to compare the results of biological monitoring activities carried out on EBDCs occupationally and environmentally exposed populations.

  9. Cancer genome-sequencing study design.

    PubMed

    Mwenifumbo, Jill C; Marra, Marco A

    2013-05-01

    Discoveries from cancer genome sequencing have the potential to translate into advances in cancer prevention, diagnostics, prognostics, treatment and basic biology. Given the diversity of downstream applications, cancer genome-sequencing studies need to be designed to best fulfil specific aims. Knowledge of second-generation cancer genome-sequencing study design also facilitates assessment of the validity and importance of the rapidly growing number of published studies. In this Review, we focus on the practical application of second-generation sequencing technology (also known as next-generation sequencing) to cancer genomics and discuss how aspects of study design and methodological considerations - such as the size and composition of the discovery cohort - can be tailored to serve specific research aims.

  10. Osseo-mechanical induction of extra-cortical plates with reference to their surface properties and geometric designs.

    PubMed

    Coathup, M J; Bates, P; Cool, P; Walker, P S; Blumenthal, N; Cobb, J P; Blunn, G W

    1999-04-01

    The purpose of this investigation was to determine which geometric and surface properties encouraged optimal ingrowth and bonding of bone to an extra-cortical plate. Forty-eight titanium extra-cortical plates were attached onto the left and right femora of adult rabbits. The plates were of six different designs and the osseoconductive effects of four surfaces were examined. A roughened titanium surface, a plasma sprayed HA coating of low crystallinity (57%) and a solution precipitated calcium phosphate coating were compared with a plasma sprayed crystalline hydroxyapatite coating (crystallinity 85%). Thin sections were prepared by grinding and polishing. Bone formation and the interface around the plates were investigated histologically and computer and morphometric analyses were used to quantify new bone formation, bone apposition onto the plate, bone porosity and the condition of the HA coating. The study found that a hydroxyapatite coating (with the exception of the solution precipitated coating) had significantly greater interfacial contact with bone when compared to a roughened titanium surface, and that significantly more bone attached to a crystalline HA coating compared with the HA coating of lower crystallinity although significantly more bone formed in the vicinity of the lower crystalline HA coating. Differences in the bony reaction induced by the various geometric designs were evident and the optimal plate design requires either holes or slots along its length as this encouraged bone ingrowth into the plate.

  11. Evaluation of potential reference genes for use in gene expression studies in the conifer pathogen (Heterobasidion annosum).

    PubMed

    Raffaello, Tommaso; Asiegbu, Fred O

    2013-07-01

    The basidiomycete Heterobasidion annosum is the causative agent of butt and root rot disease of conifer trees and it's one of the most destructive conifer pathogen in the northern hemisphere. Because of the intrinsic difficulties in genome manipulation in this fungus, most studies have been focused on gene expression analysis using quantitative real time polymerase chain reaction (qPCR). qPCR is a powerful technique but its reliability resides in the correct selection of a set of reference genes used in the data normalization. In this study, we determined the expression stability of 11 selected reference genes in H. annosum. Almost nothing has so far been published about validation of a set of reference genes to be used in gene expression experiments in this fungus. Eleven reference genes were validated in H. annosum which was grown on three different substrates: pine bark, pine heartwood, and pine sapwood. Bestkeeper and NormFinder Excel-based software were used to evaluate the reference gene transcripts' stability. The results from these two programs indicated that three reference genes namely Tryp metab, RNA Pol3 TF, and Actin were stable in H. annosum in the conditions studied. Interestingly, the GAPDH transcript which has been extensively used in qPCR data normalization is not the best choice when a wide reference gene selection is available. This work represents the first extensive validation of reference genes in H. annosum providing support for gene expression studies and benefits for the wider forest pathology community.

  12. The Multi-Disciplinary Graduate Program in Educational Research. Final Report, Part V; The Frame of Reference Study.

    ERIC Educational Resources Information Center

    Lazarsfeld, Paul F., Ed.

    This "Frame of Reference Study" consists of the fifth section of the final report of the Multi-Disciplinary Graduate Program in Educational Research of the University of Pittsburgh. The term, "frames of reference," is used to mean the context of assumptions, procedures, rules, cognitive models, and conceptions of the nature of…

  13. Office Design: A Study of Environment.

    ERIC Educational Resources Information Center

    Manning, Peter, Ed.

    Reporting upon a study of environment which was based on the design of office buildings and office space, the study forms part of a continuing program of environmental research sponsored by Pilkington Brothers Limited of St. Helens, England. In this report the word 'environment' is used in the sense of the sum of the physical and emotional…

  14. Normative Reference Values for Handgrip Strength in Colombian Schoolchildren: The FUPRECOL Study.

    PubMed

    Ramírez-Vélez, Robinson; Morales, Olimpo; Peña-Ibagon, Jhonatan C; Palacios-López, Adalberto; Prieto-Benavides, Daniel H; Vivas, Andrés; Correa-Bautista, Jorge E; Lobelo, Felipe; Alonso-Martínez, Alicia M; Izquierdo, Mikel

    2017-01-01

    Ramírez-Vélez, R, Morales, O, Peña-Ibagon, JC, Palacios-López, A, Prieto-Benavides, DH, Vivas, A, Correa-Bautista, JE, Lobelo, F, Alonso-Martínez, AM, and Izquierdo, M. Normative reference values for handgrip strength in Colombian schoolchildren: the FUPRECOL study. J Strength Cond Res 31(1): 217-226, 2017-The primary aim of this study was to generate normative handgrip (HG) strength data for 10 to 17.9 year olds. The secondary aim was to determine the relative proportion of Colombian children and adolescents that fall into established Health Benefit Zones (HBZ). This cross-sectional study enrolled 7,268 schoolchildren (boys n = 3,129 and girls n = 4,139, age 12.7 [2.4] years). Handgrip was measured using a hand dynamometer with an adjustable grip. Five HBZs (Needs Improvement, Fair, Good, Very Good, and Excellent) have been established that correspond to combined HG. Centile smoothed curves, percentile, and tables for the third, 10th, 25th, 50th, 75th, 90th, and 97th percentile were calculated using Cole's LMS method. Handgrip peaked in the sample at 22.2 (8.9) kg in boys and 18.5 (5.5) kg in girls. The increase in HG was greater for boys than for girls, but the peak HG was lower in girls than in boys. The HBZ data indicated that a higher overall percentage of boys than girls at each age group fell into the "Needs Improvement" zone, with differences particularly pronounced during adolescence. Our results provide, for the first time, sex- and age-specific HG reference standards for Colombian schoolchildren aged 9-17.9 years.

  15. P Wave Indices: Derivation of Reference Values from the Framingham Heart Study

    PubMed Central

    Magnani, Jared W.; Johnson, Victor M.; Sullivan, Lisa M.; Lubitz, Steven A.; Schnabel, Renate B.; Ellinor, Patrick T.; Benjamin, Emelia J.

    2012-01-01

    Background P wave indices, an electrocardiographic phenotype reflecting atrial electrophysiology and morphology, may be altered in multiple disease states or by cardiovascular risk factors. Reference values for P wave indices, providing cut points for their classification and interpretation, have not yet been established and are essential towards facilitating clinical application and comparison between studies. Methods We randomly selected 20 men and 20 women from 10-year age intervals between <25 years to 76–85 years from the Framingham Heart Study Original and Offspring Cohorts, excluding subjects with prevalent cardiovascular disease, hypertension, diabetes or obesity. The total included 295 subjects; eligibility in women >75 years was limited by exclusion criteria. We used a digital measurement technique with demonstrated intrarater reproducibility to determine P wave indices. P wave indices examined included the maximum, mean, lead II and PR durations, dispersion, and the standard deviation of duration. Results All P wave indices were significantly (P<0.0001) correlated with advancing age. Means of all P wave indices were lower in women as compared to men. PR interval duration was strongly correlated with maximum, mean, and lead II mean P wave durations. In multivariable models adjusting for significant anthropometric and clinical associations risk factors, significant differences persisted by age and sex in P wave indices. Conclusions In our healthy sample without cardiovascular disease, hypertension, diabetes or obesity, men and older subjects had longer mean P wave indices. Our description of P wave indices establishes reference values for future comparative studies and facilitates the classification of P wave indices. PMID:20946557

  16. Inverting the Object of Study: Recalibrating the Frame of Reference in Study Abroad Experiences

    ERIC Educational Resources Information Center

    Palmer, Norris W.

    2015-01-01

    This essay is concerned with study abroad experiences as opportunities for student cognitive development, using the interpretive lens of educational psychologist William G. Perry. A standard and often valuable assignment in courses on world religions is a site visit to a religious institution in one's local area. This may concretize otherwise…

  17. International Studies of Broadcasting; With Special Reference to the Japanese Studies.

    ERIC Educational Resources Information Center

    Eguchi, H., Ed.; Ichinohe, H., Ed.

    A set of 10 articles which first appeared in the Japanese periodical "Studies in Broadcasting" comprises this collection. Of the four essays dealing with Japan, one covers the historical changes in its broadcasting policies, treats the legal character of the Japanese public broadcasting company (Nippon Hoso Kyokai), and also reports on…

  18. Study and design of cryogenic propellant acquisition systems. Volume 1: Design studies

    NASA Technical Reports Server (NTRS)

    Burge, G. W.; Blackmon, J. B.

    1973-01-01

    An in-depth study and selection of practical propellant surface tension acquisition system designs for two specific future cryogenic space vehicles, an advanced cryogenic space shuttle auxiliary propulsion system and an advanced space propulsion module is reported. A supporting laboratory scale experimental program was also conducted to provide design information critical to concept finalization and selection. Designs using localized pressure isolated surface tension screen devices were selected for each application and preliminary designs were generated. Based on these designs, large scale acquisition prototype hardware was designed and fabricated to be compatible with available NASA-MSFC feed system hardware.

  19. The dynamics of hydroponic crops for simulation studies of the CELSS initial reference configurations

    NASA Technical Reports Server (NTRS)

    Volk, Tyler

    1992-01-01

    The goal of this research is to develop a progressive series of mathematical models for the CELSS hydroponic crops. These models will systematize the experimental findings from the crop researchers in the CELSS Program into a form useful to investigate system-level considerations, for example, dynamic studies of the CELSS Initial Reference Configurations. The crop models will organize data from different crops into a common modeling framework. This is the fifth semiannual report for this project. The following topics are discussed: (1) use of field crop models to explore phasic control of CELSS crops for optimizing yield; (2) seminar presented at Purdue CELSS NSCORT; and (3) paper submitted on analysis of bioprocessing of inedible plant materials.

  20. Studies of localized corrosion in welded aluminum alloys by the scanning reference electrode technique

    NASA Technical Reports Server (NTRS)

    Danford, M. D.; Nunes, A. C.

    1995-01-01

    Localized corrosion in welded samples of 2219-T87 Al alloy (2319 filler), 2090 Al-Li alloy (4043 and 2319 fillers), and 2195 Al-Li alloy (4043 and 2319 fillers) has been investigated using the relatively new scanning reference electrode technique. The weld beads are cathodic in all cases, leading to reduced anode/cathode ratios. A reduction in anode/cathode ratio leads to an increase in the corrosion rates of the welded metals, in agreement with results obtained in previous electrochemical and stress corrosion studies involving the overall corrosion rates of welded samples. The cathodic weld beads are bordered on both sides by strong anodic regions, with high propensity for corrosion.

  1. Reference datasets for 2-treatment, 2-sequence, 2-period bioequivalence studies.

    PubMed

    Schütz, Helmut; Labes, Detlew; Fuglsang, Anders

    2014-11-01

    It is difficult to validate statistical software used to assess bioequivalence since very few datasets with known results are in the public domain, and the few that are published are of moderate size and balanced. The purpose of this paper is therefore to introduce reference datasets of varying complexity in terms of dataset size and characteristics (balance, range, outlier presence, residual error distribution) for 2-treatment, 2-period, 2-sequence bioequivalence studies and to report their point estimates and 90% confidence intervals which companies can use to validate their installations. The results for these datasets were calculated using the commercial packages EquivTest, Kinetica, SAS and WinNonlin, and the non-commercial package R. The results of three of these packages mostly agree, but imbalance between sequences seems to provoke questionable results with one package, which illustrates well the need for proper software validation.

  2. Fundamental studies to develop certified reference material to calibrate spectrophotometer in the ultraviolet region

    NASA Astrophysics Data System (ADS)

    da Conceição, F. C.; Borges, P. P.; Gomes, J. F. S.

    2016-07-01

    Spectrophotometry is the technique used in a great number of laboratories around the world. Quantitative determination of a high number of inorganic, organic and biological species can be made by spectrophotometry using calibrated spectrophotometers. International standards require the use of optical filters to perform the calibration of spectrophotometers. One of the recommended materials is the crystalline potassium dichromate (K2Cr2O7), which is used to prepare solutions in specific concentrations for calibration or verification of spectrophotometers in the ultraviolet (UV) spectral regions. This paper presents the results concerning the fundamental studies for developing a certified reference material (CRM) of crystalline potassium dichromate to be used as standard of spectrophotometers in order to contribute to reliable quantitative analyses.

  3. Validation of reference genes for cryopreservation studies with the gorgonian coral endosymbiont Symbiodinium

    PubMed Central

    Chong, Gabriella; Kuo, Fu-Wen; Tsai, Sujune; Lin, Chiahsin

    2017-01-01

    Quantification by real-time RT-PCR requires a stable internal reference known as a housekeeping gene (HKG) for normalising the mRNA levels of target genes. The present study identified and validated stably expressed HKGs in post-thaw Symbiodinium clade G. Six potential HKGs, namely, pcna, gapdh, 18S rRNA, hsp90, rbcl, and ps1, were analysed using three different algorithms, namely, GeNorm, NormFinder, and BestKeeper. The GeNorm algorithm ranked the candidate genes as follows in the order of decreasing stability: pcna and gapdh > ps1 > 18S rRNA > hsp90 > rbcl. Results obtained using the NormFinder algorithm also showed that pcna was the most stable HKG and ps1 was the second most stable HKG. We found that the candidate HKGs examined in this study showed variable stability with respect to the three algorithms. These results indicated that both pcna and ps1 were suitable for normalising target gene expression determined by performing real-time RT-PCR in cryopreservation studies on Symbiodinium clade G. The results of the present study would help future studies to elucidate the effect of cryopreservation on gene expression in dinoflagellates. PMID:28067273

  4. A study to establish international diagnostic reference levels for paediatric computed tomography.

    PubMed

    Vassileva, J; Rehani, M; Kostova-Lefterova, D; Al-Naemi, H M; Al Suwaidi, J S; Arandjic, D; Bashier, E H O; Kodlulovich Renha, S; El-Nachef, L; Aguilar, J G; Gershan, V; Gershkevitsh, E; Gruppetta, E; Hustuc, A; Jauhari, A; Kharita, Mohammad Hassan; Khelassi-Toutaoui, N; Khosravi, H R; Khoury, H; Kralik, I; Mahere, S; Mazuoliene, J; Mora, P; Muhogora, W; Muthuvelu, P; Nikodemova, D; Novak, L; Pallewatte, A; Pekarovič, D; Shaaban, M; Shelly, E; Stepanyan, K; Thelsy, N; Visrutaratna, P; Zaman, A

    2015-07-01

    The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.

  5. Validation of Reference Housekeeping Genes for Gene Expression Studies in Western Corn Rootworm (Diabrotica virgifera virgifera)

    PubMed Central

    Barros Rodrigues, Thaís; Khajuria, Chitvan; Wang, Haichuan; Matz, Natalie; Cunha Cardoso, Danielle; Valicente, Fernando Hercos; Zhou, Xuguo; Siegfried, Blair

    2014-01-01

    Quantitative Real-time PCR (qRT-PCR) is a powerful technique to investigate comparative gene expression. In general, normalization of results using a highly stable housekeeping gene (HKG) as an internal control is recommended and necessary. However, there are several reports suggesting that regulation of some HKGs is affected by different conditions. The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a serious pest of corn in the United States and Europe. The expression profile of target genes related to insecticide exposure, resistance, and RNA interference has become an important experimental technique for study of western corn rootworms; however, lack of information on reliable HKGs under different conditions makes the interpretation of qRT-PCR results difficult. In this study, four distinct algorithms (Genorm, NormFinder, BestKeeper and delta-CT) and five candidate HKGs to genes of reference (β-actin; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; β-tubulin; RPS9, ribosomal protein S9; EF1a, elongation factor-1α) were evaluated to determine the most reliable HKG under different experimental conditions including exposure to dsRNA and Bt toxins and among different tissues and developmental stages. Although all the HKGs tested exhibited relatively stable expression among the different treatments, some differences were noted. Among the five candidate reference genes evaluated, β-actin exhibited highly stable expression among different life stages. RPS9 exhibited the most similar pattern of expression among dsRNA treatments, and both experiments indicated that EF1a was the second most stable gene. EF1a was also the most stable for Bt exposure and among different tissues. These results will enable researchers to use more accurate and reliable normalization of qRT-PCR data in WCR experiments. PMID:25356627

  6. Validation of reference genes for quantitative gene expression studies in Volvox carteri using real-time RT-PCR.

    PubMed

    Kianianmomeni, Arash; Hallmann, Armin

    2013-12-01

    Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) is a sensitive technique for analysis of gene expression under a wide diversity of biological conditions. However, the identification of suitable reference genes is a critical factor for analysis of gene expression data. To determine potential reference genes for normalization of qRT-PCR data in the green alga Volvox carteri, the transcript levels of ten candidate reference genes were measured by qRT-PCR in three experimental sample pools containing different developmental stages, cell types and stress treatments. The expression stability of the candidate reference genes was then calculated using the algorithms geNorm, NormFinder and BestKeeper. The genes for 18S ribosomal RNA (18S) and eukaryotic translation elongation factor 1α2 (eef1) turned out to have the most stable expression levels among the samples both from different developmental stages and different stress treatments. The genes for the ribosomal protein L23 (rpl23) and the TATA-box binding protein (tbpA) showed equivalent transcript levels in the comparison of different cell types, and therefore, can be used as reference genes for cell-type specific gene expression analysis. Our results indicate that more than one reference gene is required for accurate normalization of qRT-PCRs in V. carteri. The reference genes in our study show a much better performance than the housekeeping genes used as a reference in previous studies.

  7. Latent class models in diagnostic studies when there is no reference standard--a systematic review.

    PubMed

    van Smeden, Maarten; Naaktgeboren, Christiana A; Reitsma, Johannes B; Moons, Karel G M; de Groot, Joris A H

    2014-02-15

    Latent class models (LCMs) combine the results of multiple diagnostic tests through a statistical model to obtain estimates of disease prevalence and diagnostic test accuracy in situations where there is no single, accurate reference standard. We performed a systematic review of the methodology and reporting of LCMs in diagnostic accuracy studies. This review shows that the use of LCMs in such studies increased sharply in the past decade, notably in the domain of infectious diseases (overall contribution: 59%). The 64 reviewed studies used a range of differently specified parametric latent variable models, applying Bayesian and frequentist methods. The critical assumption underlying the majority of LCM applications (61%) is that the test observations must be independent within 2 classes. Because violations of this assumption can lead to biased estimates of accuracy and prevalence, performing and reporting checks of whether assumptions are met is essential. Unfortunately, our review shows that 28% of the included studies failed to report any information that enables verification of model assumptions or performance. Because of the lack of information on model fit and adequate evidence "external" to the LCMs, it is often difficult for readers to judge the validity of LCM-based inferences and conclusions reached.

  8. Design and Development of an Equipotential Voltage Reference (Grounding) System for a Low-Cost Rapid-Development Modular Spacecraft Architecture

    NASA Technical Reports Server (NTRS)

    Lukash, James A.; Daley, Earl

    2011-01-01

    This work describes the design and development effort to adapt rapid-development space hardware by creating a ground system using solutions of low complexity, mass, & cost. The Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft is based on the modular common spacecraft bus architecture developed at NASA Ames Research Center. The challenge was building upon the existing modular common bus design and development work and improving the LADEE spacecraft design by adding an Equipotential Voltage Reference (EVeR) system, commonly referred to as a ground system. This would aid LADEE in meeting Electromagnetic Environmental Effects (E3) requirements, thereby making the spacecraft more compatible with itself and its space environment. The methods used to adapt existing hardware are presented, including provisions which may be used on future spacecraft.

  9. Proton-binding study of standard and reference fulvic acids, humic acids, and natural organic matter

    NASA Astrophysics Data System (ADS)

    Ritchie, Jason D.; Perdue, E. Michael

    2003-01-01

    The acid-base properties of 14 standard and reference materials from the International Humic Substances Society (IHSS) were investigated by potentiometric titration. Titrations were conducted in 0.1 M NaCl under a nitrogen atmosphere, averaging 30 min from start to finish. Concentrations of carboxyl groups and phenolic groups were estimated directly from titration curves. Titration data were also fit to a modified Henderson-Hasselbalch model for two classes of proton-binding sites to obtain "best fit" parameters that describe proton-binding curves for the samples. The model was chosen for its simplicity, its ease of implementation in computer spreadsheets, and its excellent ability to describe the shapes of the titration curves. The carboxyl contents of the IHSS samples are in the general order: terrestrial fulvic acids > aquatic fulvic acids > Suwannee River natural organic matter (NOM) > aquatic humic acids > terrestrial humic acids. Overall, fulvic acids and humic acids have similar phenolic contents; however, all of the aquatically derived samples have higher phenolic contents than the terrestrially derived samples. The acid-base properties of reference Suwannee River NOM are surprisingly similar to those of standard Suwannee River humic acid. Results from titrations in this study were compared with other published results from both direct and indirect titrations. Typically, carboxyl contents for the IHSS samples were in agreement with the results from both methods of titration. Phenolic contents for the IHSS samples were comparable to those determined by direct titrations, but were significantly less than estimates of phenolic content that were based on indirect titrations with Ba(OH) 2 and Ca(OAc) 2. The average phenolic-to-carboxylic ratio of the IHSS samples is approximately 1:4. Models that assume a 1:2 ratio of phenolic-to-carboxylic groups may overestimate the relative contribution of phenolic groups to the acid-base chemistry of humic substances.

  10. Physical and psychosocial risk factors for lateral epicondylitis: a population based case-referent study

    PubMed Central

    Haahr, J; Andersen, J

    2003-01-01

    Aims: To assess the importance of physical and psychosocial risk factors for lateral epicondylitis (tennis elbow). Methods: Case-referent study of 267 new cases of tennis elbow and 388 referents from the background population enrolled from general practices in Ringkjoebing County, Denmark. Results: Manual job tasks were associated with tennis elbow (odds ratio (OR) 3.1, 95% confidence interval (CI) 1.9 to 5.1). The self reported physical risk factors "posture" and "forceful work" were related to tennis elbow. Among women, work involving performing repeated movements of the arms was related to tennis elbow (OR 3.7, CI 1.7 to 8.3). Among men, work with precision demanding movements was related to tennis elbow (OR 5.2, CI 1.5 to 17.9). Among both males and females, the results for work with hand held vibrating tools were inconsistent, partly because of few exposed subjects. A physical strain index was established based on posture, repetition, and force. The adjusted ORs for tennis elbow at low, medium, and high strain were 1.4 (CI 0.8 to 2.7), 2.0 (CI 1.1 to 3.7), and 4.4 (CI 2.3 to 8.7). Low social support at work, adjusted for physical strain, was a risk factor among women (OR 2.4, CI 1.3 to 4.6). Conclusion: Results indicate that being a new case of tennis elbow is associated with non-neutral postures of hands and arms, use of heavy hand held tools, and high physical strain measured as a combination of forceful work, non-neutral posture of hands and arms, and repetition. Furthermore, tennis elbow among women was associated with low social support at work. The results for precision demanding movements and for vibration were less consistent. PMID:12709516

  11. Identification and Validation of Reference Genes for qRT-PCR Studies of Gene Expression in Dioscorea opposita

    PubMed Central

    Zhao, Xiting; Zhang, Xiaoli; Guo, Xiaobo; Li, Shujie; Han, Linlin; Song, Zhihui; Wang, Yunying; Li, Junhua; Li, Mingjun

    2016-01-01

    Quantitative real-time polymerase chain reaction (qRT-PCR) is one of the most common methods for gene expression studies. Data normalization based on reference genes is essential for obtaining reliable results for qRT-PCR assays. This study evaluated potential reference genes of Chinese yam (Dioscorea opposita Thunb.), which is an important tuber crop and medicinal plant in East Asia. The expression of ten candidate reference genes across 20 samples from different organs and development stages was assessed. We identified the most stable genes for qRT-PCR studies using combined samples from different organs. Our results also suggest that different suitable reference genes or combinations of reference genes for normalization should be applied according to different organs and developmental stages. To validate the suitability of the reference genes, we evaluated the relative expression of PE2.1 and PE53, which are two genes that may be associated with microtuber formation. Our results provide the foundation for reference gene(s) selection in D. opposita and will contribute toward more accurate gene analysis studies of the genus Dioscorea. PMID:27314014

  12. Identification and Validation of Reference Genes for qRT-PCR Studies of Gene Expression in Dioscorea opposita.

    PubMed

    Zhao, Xiting; Zhang, Xiaoli; Guo, Xiaobo; Li, Shujie; Han, Linlin; Song, Zhihui; Wang, Yunying; Li, Junhua; Li, Mingjun

    2016-01-01

    Quantitative real-time polymerase chain reaction (qRT-PCR) is one of the most common methods for gene expression studies. Data normalization based on reference genes is essential for obtaining reliable results for qRT-PCR assays. This study evaluated potential reference genes of Chinese yam (Dioscorea opposita Thunb.), which is an important tuber crop and medicinal plant in East Asia. The expression of ten candidate reference genes across 20 samples from different organs and development stages was assessed. We identified the most stable genes for qRT-PCR studies using combined samples from different organs. Our results also suggest that different suitable reference genes or combinations of reference genes for normalization should be applied according to different organs and developmental stages. To validate the suitability of the reference genes, we evaluated the relative expression of PE2.1 and PE53, which are two genes that may be associated with microtuber formation. Our results provide the foundation for reference gene(s) selection in D. opposita and will contribute toward more accurate gene analysis studies of the genus Dioscorea.

  13. Preliminary design study of a baseline MIUS

    NASA Technical Reports Server (NTRS)

    Wolfer, B. M.; Shields, V. E.; Rippey, J. O.; Roberts, H. L.; Wadle, R. C.; Wallin, S. P.; Gill, W. L.; White, E. H.; Monzingo, R.

    1977-01-01

    Results of a conceptual design study to establish a baseline design for a modular integrated utility system (MIUS) are presented. The system concept developed a basis for evaluating possible projects to demonstrate an MIUS. For the baseline study, climate conditions for the Washington, D.C., area were used. The baseline design is for a high density apartment complex of 496 dwelling units with a planned full occupancy of approximately 1200 residents. Environmental considerations and regulations for the MIUS installation are discussed. Detailed cost data for the baseline MIUS are given together with those for design and operating variations under climate conditions typified by Las Vegas, Nevada, Houston, Texas, and Minneapolis, Minnesota. In addition, results of an investigation of size variation effects, for 300 and 1000 unit apartment complexes, are presented. Only conceptual aspects of the design are discussed. Results regarding energy savings and costs are intended only as trend information and for use in relative comparisons. Alternate heating, ventilation, and air conditioning concepts are considered in the appendix.

  14. Deepening Kindergarteners' Science Vocabulary: A Design Study

    ERIC Educational Resources Information Center

    Parsons, Allison Ward; Bryant, Camille Lawrence

    2016-01-01

    Early, effective instruction to introduce both science vocabulary and general academic language may help children build a strong conceptual and linguistic foundation for later instruction. In this study, a design research intervention was employed to expose children to a variety of interrelated science content words to increase both the breadth…

  15. Designing a Futuristic Business Studies Curriculum

    ERIC Educational Resources Information Center

    Mei, Chiew Wye; Siraj, Saedah

    2013-01-01

    This paper is a discourse on the theoretical aspects underpinning the design of the Business Studies curriculum domain. It draws on recent shifts in the business and educational environment of Malaysia, and maps out the methodology and method for expanding and revamping the core ground of the discipline. Using the pragmatic worldview stance, this…

  16. Quiet engine program flight engine design study

    NASA Technical Reports Server (NTRS)

    Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

    1974-01-01

    The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

  17. Overall Rationale and Design of Study.

    ERIC Educational Resources Information Center

    Hegsted, D. Mark

    This paper outlines research designed to establish dietary correlates of malnutrition, and questions the common assumption that high protein foods should be used as dietary supplements in humans. Because thorough investigation of dietary needs in children is ethically unfeasible, squirrel monkeys were used in the research to study the biological…

  18. Collaborative study for the establishment of replacement batches for human coagulation factor IX concentrate reference standards.

    PubMed

    Gray, E; Pickering, W; Hockley, J; Rigsby, P; Weinstein, M; Terao, E; Buchheit, K-H

    2008-12-01

    The European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) batch 1, the World Health Organisation (WHO) 3rd International Standard, Human (IS, 96/854) and the FDA Standard for human blood coagulation Factor IX concentrate have been available since 1996, following their establishment by a common collaborative study. Due to dwindling stocks of all three standards, a new WHO-EDQM-FDA tri-partite collaborative study was launched to establish replacement batches. Thirty laboratories from fourteen countries took part in the collaborative study to assign potency values to candidate preparations. Three candidates, one of recombinant and two of human plasma-derived origins, were assayed against the 3rd IS for Blood Coagulation Factor IX, Concentrate, Human (96/854). The 3rd IS for Blood Coagulation Factors II, VII, IX and X, Plasma, Human (99/826) was also included to evaluate the relationship between the factor IX plasma and concentrate unitage. Thirty-two sets of clotting assay results and two sets of chromogenic assay data were analysed. There was a significant difference in potency estimates by these two methods for the recombinant candidate (sample B) and the plasma IS (sample P). Similar potency values were obtained for the plasma derived products (monoclonal antibody- and chromatography-purified factor IX, samples C and D) by clotting and chromogenic assays. For the clotting assays, intra-laboratory variability (GCV) was found to range from 0.5 - 21.7%, with the GCV for the majority of laboratories being less than 10%. Good inter-laboratory agreement, with the majority of the GCV being less than 10% (GCV range = 4.7 - 10.6 %) was also obtained. The mean potency values estimated by the clotting assay using plasma as pre-diluent (as directed by the Ph. Eur. general chapter method) did not differ from values obtained using buffer. Taking into account the preliminary stability data, the intra- and inter-laboratory variability, and the differences

  19. A CASE STUDY OF THE REFERENCE CONDITION APPROACH TO NITROGEN MANAGEMENT IN ESTUARIES

    EPA Science Inventory

    One way to estimate estuarine response to changes in nitrogen loading in coastal systems is by using a reference approach. This talk details the application of paleoecological analysis and use of historical data to estimate reference loads of nitrogen to New Bedford Harbor (NBH),...

  20. A Survey of Telephone Inquiries: Case Study and Operational Impact in an Academic Library Reference Department.

    ERIC Educational Resources Information Center

    Allen, Frank R.; Smith, Rita H.

    1993-01-01

    Describes a survey that was conducted at the University of Tennessee at Knoxville library to count and categorize the types of questions coming into the reference department from telephone calls. Informational and directional calls are examined, implications for staffing are considered, and queuing theory is applied. (seven references) (LRW)

  1. Solar power satellite system definition study, phase 2. Volume 2: Reference system description

    NASA Technical Reports Server (NTRS)

    1979-01-01

    System descriptions and cost estimates for the reference system of the solar power satellite program are presented. The reference system is divided into five principal elements: the solar power satellites; space construction and support; space and ground transportation; ground receiving stations; and operations control. The program scenario and non-recurring costs are briefly described.

  2. LST phase A design update study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An update is presented of the Phase A study of the Large Space Telescope (LST), based on changes in guidelines and new data developed subsequent to the Phase A study. The study defines an LST concept based on the broad mission guidelines provided by the Office of Space Science (OSS), the scientific requirements developed by OSS with the scientific community, and an understanding of long range NASA planning current at the time the study was performed. A low cost design approach was followed. This resulted in the use of standard spacecraft hardware, the provision for maintenance at the black box level, growth potential in systems designs, and sharing of shuttle maintenance flights with other payloads (See N73-18449 through N73-18453)

  3. Competencies for Adult Basic Education and Diploma Programs: A Summary of Studies and Cross-Reference of Results.

    ERIC Educational Resources Information Center

    Fischer, Joan Keller

    This report summarizes and cross-references the results of 12 studies dealing with competencies for Adult Basic Education (ABE) and diploma programs. Described in the report are the following studies/projects: (1) the Adult Performance Level (APL) Study; (2) five APL-based validation studies (the New Jersey ABE Study, the New Jersey English as a…

  4. Comparative transcriptomics among floral organs of the basal eudicot Eschscholzia californica as reference for floral evolutionary developmental studies

    PubMed Central

    2010-01-01

    Background Molecular genetic studies of floral development have concentrated on several core eudicots and grasses (monocots), which have canalized floral forms. Basal eudicots possess a wider range of floral morphologies than the core eudicots and grasses and can serve as an evolutionary link between core eudicots and monocots, and provide a reference for studies of other basal angiosperms. Recent advances in genomics have enabled researchers to profile gene activities during floral development, primarily in the eudicot Arabidopsis thaliana and the monocots rice and maize. However, our understanding of floral developmental processes among the basal eudicots remains limited. Results Using a recently generated expressed sequence tag (EST) set, we have designed an oligonucleotide microarray for the basal eudicot Eschscholzia californica (California poppy). We performed microarray experiments with an interwoven-loop design in order to characterize the E. californica floral transcriptome and to identify differentially expressed genes in flower buds with pre-meiotic and meiotic cells, four floral organs at pre-anthesis stages (sepals, petals, stamens and carpels), developing fruits, and leaves. Conclusions Our results provide a foundation for comparative gene expression studies between eudicots and basal angiosperms. We identified whorl-specific gene expression patterns in E. californica and examined the floral expression of several gene families. Interestingly, most E. californica homologs of Arabidopsis genes important for flower development, except for genes encoding MADS-box transcription factors, show different expression patterns between the two species. Our comparative transcriptomics study highlights the unique evolutionary position of E. californica compared with basal angiosperms and core eudicots. PMID:20950453

  5. A geospatial reference framework for a university campus: a case study for managing student surveyed topographic data

    NASA Astrophysics Data System (ADS)

    Fraser, D.; Sepehr, S.; Stefanakis, E.

    2014-11-01

    This presentation describes a geospatial reference framework for managing student surveyed topographic data of a university campus. This topographic data is collected annually by Geodesy and Geomatics Engineering (GGE) students at the University of New Brunswick (UNB) as part of the requirements for a UNB course. Examples of the type of features collected include: buildings, roads, sidewalks, walking paths, bike racks, parking lots and parking designation (e.g. accessibility parking). The applications and the information products built for managing this student surveyed topographic data can be viewed as a geospatial reference framework for this GGE survey camp.

  6. An empirical study of software design practices

    NASA Technical Reports Server (NTRS)

    Card, David N.; Church, Victor E.; Agresti, William W.

    1986-01-01

    Software engineers have developed a large body of software design theory and folklore, much of which was never validated. The results of an empirical study of software design practices in one specific environment are presented. The practices examined affect module size, module strength, data coupling, descendant span, unreferenced variables, and software reuse. Measures characteristic of these practices were extracted from 887 FORTRAN modules developed for five flight dynamics software projects monitored by the Software Engineering Laboratory (SEL). The relationship of these measures to cost and fault rate was analyzed using a contingency table procedure. The results show that some recommended design practices, despite their intuitive appeal, are ineffective in this environment, whereas others are very effective.

  7. Assessment of brain reference genes for RT-qPCR studies in neurodegenerative diseases

    PubMed Central

    Rydbirk, Rasmus; Folke, Jonas; Winge, Kristian; Aznar, Susana; Pakkenberg, Bente; Brudek, Tomasz

    2016-01-01

    Evaluation of gene expression levels by reverse transcription quantitative real-time PCR (RT-qPCR) has for many years been the favourite approach for discovering disease-associated alterations. Normalization of results to stably expressed reference genes (RGs) is pivotal to obtain reliable results. This is especially important in relation to neurodegenerative diseases where disease-related structural changes may affect the most commonly used RGs. We analysed 15 candidate RGs in 98 brain samples from two brain regions from Alzheimer’s disease (AD), Parkinson’s disease (PD), Multiple System Atrophy, and Progressive Supranuclear Palsy patients. Using RefFinder, a web-based tool for evaluating RG stability, we identified the most stable RGs to be UBE2D2, CYC1, and RPL13 which we recommend for future RT-qPCR studies on human brain tissue from these patients. None of the investigated genes were affected by experimental variables such as RIN, PMI, or age. Findings were further validated by expression analyses of a target gene GSK3B, known to be affected by AD and PD. We obtained high variations in GSK3B levels when contrasting the results using different sets of common RG underlining the importance of a priori validation of RGs for RT-qPCR studies. PMID:27853238

  8. Proposal for a revised Reference Concentration (RfC) for manganese based on recent epidemiological studies.

    PubMed

    Bailey, Lisa A; Goodman, Julie E; Beck, Barbara D

    2009-12-01

    In 1993, based on observations of subclinical neurological effects in workers, the United States Environmental Protection Agency (US EPA) published a Reference Concentration (RfC) of 0.05 microg/m(3) for manganese (Mn). The geometric mean exposure concentration, 150 microg/m(3) respirable Mn, was considered the lowest observable adverse effect level (LOAEL), and uncertainty factors (UFs) were applied to account for sensitive populations, database limitations, a LOAEL, subchronic exposure, and potential differences in toxicity of different forms of Mn. Based on a review of more recent literature, we propose two alternate Mn RfCs. Of 12 more recent occupational studies of eight cohorts with chronic exposure durations, examining subclinical neurobehavioral effects, predominantly on the motor system, three were considered appropriate for development of an RfC. All three studies yielded no observable adverse effect levels (NOAELs) of approximately 60 microg/m(3) respirable Mn. Converting the occupational NOAEL to a human equivalent concentration (HEC) of 21microg/m(3) (for continuous exposure) and applying a UF of 10 to account for intraspecies variability yielded an RfC of 2microg/m(3). We also derived a similar RfC (7 microg/m(3)) using an Mn benchmark dose (BMD) as the point of departure. Overall confidence in both RfCs is medium.

  9. Searching for missing heritability: Designing rare variant association studies

    PubMed Central

    Zuk, Or; Schaffner, Stephen F.; Samocha, Kaitlin; Do, Ron; Hechter, Eliana; Kathiresan, Sekar; Daly, Mark J.; Neale, Benjamin M.; Sunyaev, Shamil R.; Lander, Eric S.

    2014-01-01

    Genetic studies have revealed thousands of loci predisposing to hundreds of human diseases and traits, revealing important biological pathways and defining novel therapeutic hypotheses. However, the genes discovered to date typically explain less than half of the apparent heritability. Because efforts have largely focused on common genetic variants, one hypothesis is that much of the missing heritability is due to rare genetic variants. Studies of common variants are typically referred to as genomewide association studies, whereas studies of rare variants are often simply called sequencing studies. Because they are actually closely related, we use the terms common variant association study (CVAS) and rare variant association study (RVAS). In this paper, we outline the similarities and differences between RVAS and CVAS and describe a conceptual framework for the design of RVAS. We apply the framework to address key questions about the sample sizes needed to detect association, the relative merits of testing disruptive alleles vs. missense alleles, frequency thresholds for filtering alleles, the value of predictors of the functional impact of missense alleles, the potential utility of isolated populations, the value of gene-set analysis, and the utility of de novo mutations. The optimal design depends critically on the selection coefficient against deleterious alleles and thus varies across genes. The analysis shows that common variant and rare variant studies require similarly large sample collections. In particular, a well-powered RVAS should involve discovery sets with at least 25,000 cases, together with a substantial replication set. PMID:24443550

  10. Cryogenic Propellant Management Device: Conceptual Design Study

    NASA Technical Reports Server (NTRS)

    Wollen, Mark; Merino, Fred; Schuster, John; Newton, Christopher

    2010-01-01

    Concepts of Propellant Management Devices (PMDs) were designed for lunar descent stage reaction control system (RCS) and lunar ascent stage (main and RCS propulsion) missions using liquid oxygen (LO2) and liquid methane (LCH4). Study ground rules set a maximum of 19 days from launch to lunar touchdown, and an additional 210 days on the lunar surface before liftoff. Two PMDs were conceptually designed for each of the descent stage RCS propellant tanks, and two designs for each of the ascent stage main propellant tanks. One of the two PMD types is a traditional partial four-screen channel device. The other type is a novel, expanding volume device which uses a stretched, flexing screen. It was found that several unique design features simplified the PMD designs. These features are (1) high propellant tank operating pressures, (2) aluminum tanks for propellant storage, and (3) stringent insulation requirements. Consequently, it was possible to treat LO2 and LCH4 as if they were equivalent to Earth-storable propellants because they would remain substantially subcooled during the lunar mission. In fact, prelaunch procedures are simplified with cryogens, because any trapped vapor will condense once the propellant tanks are pressurized in space.

  11. Study of unconventional aircraft engines designed for low energy consumption

    NASA Technical Reports Server (NTRS)

    Neitzel, R. E.; Hirschkron, R.; Johnston, R. P.

    1976-01-01

    A study of unconventional engine cycle concepts, which may offer significantly lower energy consumption than conventional subsonic transport turbofans, is described herein. A number of unconventional engine concepts were identified and parametrically studied to determine their relative fuel-saving potential. Based on results from these studies, regenerative, geared, and variable-boost turbofans, and combinations thereof, were selected along with advanced turboprop cycles for further evaluation and refinement. Preliminary aerodynamic and mechanical designs of these unconventional engine configurations were conducted and mission performance was compared to a conventional, direct-drive turofan reference engine. Consideration is given to the unconventional concepts, and their state of readiness for application. Areas of needed technology advancement are identified.

  12. Evaluation and Validation of Reference Genes for Normalization of Quantitative Real-Time PCR Based Gene Expression Studies in Peanut

    PubMed Central

    Cindhuri, Katamreddy Sri; Sharma, Kiran K.

    2013-01-01

    The quantitative real-time PCR (qPCR) based techniques have become essential for gene expression studies and high-throughput molecular characterization of transgenic events. Normalizing to reference gene in relative quantification make results from qPCR more reliable when compared to absolute quantification, but requires robust reference genes. Since, ideal reference gene should be species specific, no single internal control gene is universal for use as a reference gene across various plant developmental stages and diverse growth conditions. Here, we present validation studies of multiple stably expressed reference genes in cultivated peanut with minimal variations in temporal and spatial expression when subjected to various biotic and abiotic stresses. Stability in the expression of eight candidate reference genes including ADH3, ACT11, ATPsyn, CYP2, ELF1B, G6PD, LEC and UBC1 was compared in diverse peanut plant samples. The samples were categorized into distinct experimental sets to check the suitability of candidate genes for accurate and reliable normalization of gene expression using qPCR. Stability in expression of the references genes in eight sets of samples was determined by geNorm and NormFinder methods. While three candidate reference genes including ADH3, G6PD and ELF1B were identified to be stably expressed across experiments, LEC was observed to be the least stable, and hence must be avoided for gene expression studies in peanut. Inclusion of the former two genes gave sufficiently reliable results; nonetheless, the addition of the third reference gene ELF1B may be potentially better in a diverse set of tissue samples of peanut. PMID:24167633

  13. Evaluation and validation of reference genes for normalization of quantitative real-time PCR based gene expression studies in peanut.

    PubMed

    Reddy, Dumbala Srinivas; Bhatnagar-Mathur, Pooja; Cindhuri, Katamreddy Sri; Sharma, Kiran K

    2013-01-01

    The quantitative real-time PCR (qPCR) based techniques have become essential for gene expression studies and high-throughput molecular characterization of transgenic events. Normalizing to reference gene in relative quantification make results from qPCR more reliable when compared to absolute quantification, but requires robust reference genes. Since, ideal reference gene should be species specific, no single internal control gene is universal for use as a reference gene across various plant developmental stages and diverse growth conditions. Here, we present validation studies of multiple stably expressed reference genes in cultivated peanut with minimal variations in temporal and spatial expression when subjected to various biotic and abiotic stresses. Stability in the expression of eight candidate reference genes including ADH3, ACT11, ATPsyn, CYP2, ELF1B, G6PD, LEC and UBC1 was compared in diverse peanut plant samples. The samples were categorized into distinct experimental sets to check the suitability of candidate genes for accurate and reliable normalization of gene expression using qPCR. Stability in expression of the references genes in eight sets of samples was determined by geNorm and NormFinder methods. While three candidate reference genes including ADH3, G6PD and ELF1B were identified to be stably expressed across experiments, LEC was observed to be the least stable, and hence must be avoided for gene expression studies in peanut. Inclusion of the former two genes gave sufficiently reliable results; nonetheless, the addition of the third reference gene ELF1B may be potentially better in a diverse set of tissue samples of peanut.

  14. Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team

    NASA Technical Reports Server (NTRS)

    Hoffman, Stephen J. (Editor); Kaplan, David I. (Editor)

    1997-01-01

    Personnel representing several NASA field centers have formulated a "Reference Mission" addressing human exploration of Mars. This report summarizes their work and describes a plan for the first human missions to Mars, using approaches that are technically feasible, have reasonable risks, and have relatively low costs. The architecture for the Mars Reference Mission builds on previous work of the Synthesis Group (1991) and Zubrin's (1991) concepts for the use of propellants derived from the Martian Atmosphere. In defining the Reference Mission, choices have been made. In this report, the rationale for each choice is documented; however, unanticipated technology advances or political decisions might change the choices in the future.

  15. Interreligious education: Conceptualising a needs assessment framework for curriculum design in plural societies (with special reference to Mauritius)

    NASA Astrophysics Data System (ADS)

    Maudarbux, Mohammad Belall

    2016-08-01

    The growing debate on intercultural and interreligious dialogue has one major drawback: how to translate academic and theoretical contributions into practical tools for educators and policy makers. This paper aims to fill this gap by presenting a transferable "needs assessment model" based on five criteria and twenty measurable indicators of interreligious relations within a country. Using the example of Mauritius, a densely multilingual and multireligious country, the paper gives an inside view of the preparations which led to the launch of an innovative "Peace and Interfaith Studies" course at the University of Mauritius in 2010. The author was himself involved first as a curriculum consultant and then as a project manager of this course at the Council of Religions in Mauritius. After clarifying the differences between related concepts like multicultural education, intercultural education and religious education, the author defines "interreligious education" as being distinct from all of the above. The paper then proceeds to explain the rationale of interreligious education, followed by the identification of the critical factors which affect curriculum design and policy making. It uses these factors to highlight how each of them operates in Mauritius to create a web of complexity which makes interreligious education extremely volatile. This is followed by an overview of religious education in the Mauritian schooling system, an overview of the needs assessment framework and a description of the innovative "Peace and Interfaith Studies" course. The paper ends with a brief discussion of the main challenges of this model.

  16. Identification of suitable reference genes for gene expression studies by qRT-PCR in the blister beetle Mylabris cichorii.

    PubMed

    Wang, Yu; Wang, Zhong-Kang; Huang, Yi; Liao, Yu-Feng; Yin, You-Ping

    2014-01-01

    The blister beetle Mylabris cichorii L. (Coleoptera: Meloidae) is a traditional medicinal insect recorded in the Chinese Pharmacopoeia. It synthesizes cantharidin, which kills cancer cells efficiently. Only males produce large amounts of cantharidin. Reference genes are required as endogenous controls for the analysis of differential gene expression in M. cichorii. Our study chose 10 genes as candidate reference genes. The stability of expression of these genes was analyzed by quantitative PCR and determined with two algorithms, geNorm and Normfinder. We recommend UBE3A and RPL22e as suitable reference genes in females and UBE3A, TAF5, and RPL22e in males.

  17. Identification of Suitable Reference Genes for gene Expression Studies by qRT-PCR in the Blister Beetle Mylabris cichorii

    PubMed Central

    Wang, Yu; Wang, Zhong-Kang; Huang, Yi; Liao, Yu-Feng; Yin, You-Ping

    2014-01-01

    The blister beetle Mylabris cichorii L. (Coleoptera: Meloidae) is a traditional medicinal insect recorded in the Chinese Pharmacopoeia. It synthesizes cantharidin, which kills cancer cells efficiently. Only males produce large amounts of cantharidin. Reference genes are required as endogenous controls for the analysis of differential gene expression in M. cichorii. Our study chose 10 genes as candidate reference genes. The stability of expression of these genes was analyzed by quantitative PCR and determined with two algorithms, geNorm and Normfinder. We recommend UBE3A and RPL22e as suitable reference genes in females and UBE3A, TAF5, and RPL22e in males. PMID:25368050

  18. SDU 6 MODELING STUDY TO SUPPORT DESIGN DEVELOPMENT

    SciTech Connect

    Smith, F.

    2012-05-02

    In response to Technical Task Request (TTR) HLW-SSF-TTR-2012-0017 (1), SRNL performed modeling studies to evaluate alternative design features for the 32 million gallon Saltstone Disposal Unit (SDU) referred to as SDU 6. This initial modeling study was intended to assess the performance of major components of the structure that are most significant to the PA. Information provided by the modeling will support the development of a SDU 6 Preliminary Design Model and Recommendation Report to be written by SRR Closure and Waste Disposal Authority. Key inputs and assumptions for the modeling were provided to SRNL in SRR-SPT-2011-00113 (2). A table reiterates the base case and four sensitivity case studies requested in this reference. In general, as shown in Table 4, when compared to Vault 2 Case A, the Base Case SDU 6 design produced higher peak fluxes to the water table during the 10,000 year period of analysis but lower peak fluxes within a 15,000 to 20,000 time frame. SDU 6 will contain approximately ten times the inventory of a single Vault 2 and the SDU 6 footprint is comparable to that of a group of four Vault 2 disposal units. Therefore, the radionuclide flux from SDU 6 and that from a single Vault 2 are not directly comparable. A more direct comparison would be to compare the maximum dose obtained at the 100 m boundary from the seven SDU's that will replace the 64 FDC's analyzed in the 2009 PA. This analysis will be performed in the next set of calculations planned for SDU design evaluation. Aquifer transport and dose calculations were not intended to be part of this initial scoping study. However, results from this study do indicate that replacement of the FDC design with SDU would not yield significantly higher peak doses. If the thickness of the SDU 6 floor is increased, peak doses would not occur during the 10,000 year period of analysis.

  19. Challenges in Collating Spirometry Reference Data for South-Asian Children: An Observational Study

    PubMed Central

    Lum, Sooky; Bountziouka, Vassiliki; Quanjer, Philip; Sonnappa, Samatha; Wade, Angela; Beardsmore, Caroline; Chhabra, Sunil K.; Chudasama, Rajesh K.; Cook, Derek G.; Harding, Seeromanie; Kuehni, Claudia E.; Prasad, K. V. V.; Whincup, Peter H.; Lee, Simon; Stocks, Janet

    2016-01-01

    Availability of sophisticated statistical modelling for developing robust reference equations has improved interpretation of lung function results. In 2012, the Global Lung function Initiative(GLI) published the first global all-age, multi-ethnic reference equations for spirometry but these lacked equations for those originating from the Indian subcontinent (South-Asians). The aims of this study were to assess the extent to which existing GLI-ethnic adjustments might fit South-Asian paediatric spirometry data, assess any similarities and discrepancies between South-Asian datasets and explore the feasibility of deriving a suitable South-Asian GLI-adjustment. Methods Spirometry datasets from South-Asian children were collated from four centres in India and five within the UK. Records with transcription errors, missing values for height or spirometry, and implausible values were excluded(n = 110). Results Following exclusions, cross-sectional data were available from 8,124 children (56.3% male; 5–17 years). When compared with GLI-predicted values from White Europeans, forced expired volume in 1s (FEV1) and forced vital capacity (FVC) in South-Asian children were on average 15% lower, ranging from 4–19% between centres. By contrast, proportional reductions in FEV1 and FVC within all but two datasets meant that the FEV1/FVC ratio remained independent of ethnicity. The ‘GLI-Other’ equation fitted data from North India reasonably well while ‘GLI-Black’ equations provided a better approximation for South-Asian data than the ‘GLI-White’ equation. However, marked discrepancies in the mean lung function z-scores between centres especially when examined according to socio-economic conditions precluded derivation of a single South-Asian GLI-adjustment. Conclusion Until improved and more robust prediction equations can be derived, we recommend the use of ‘GLI-Black’ equations for interpreting most South-Asian data, although ‘GLI-Other’ may be more

  20. Societal Burden of Clinically Anxious Youth Referred for Treatment: A Cost-of-illness Study

    PubMed Central

    Dirksen, Carmen D.; Bögels, Susan M.

    2008-01-01

    A prevalence-based cost-of-illness study using a societal perspective was conducted to investigate the cost-of-illness in clinically anxious youth aged 8–18 in The Netherlands. Discriminant validity of the cost diary used was obtained by comparing costs of families with an anxious child (n = 118) to costs of families from the general population (n = 41). To examine the convergent validity, bottom-up acquired costs derived from cost diaries were compared to top-down acquired costs obtained from national registrations. Bottom-up acquired costs measured by means of cost diaries amounted to €2,748 per family of a clinically referred anxious child per annum. Societal costs of families with clinically anxious children were almost 21 times as high compared to families from the general population. With respect to convergent validity, total health care costs using the bottom-up approach from clinically anxious children were quite comparable to those of top-down data of anxious children, although costs within the subcategories differed considerably. Clinical anxiety disorders in childhood cost the Dutch society more than 20 million euros a year. Based on results of discriminate and convergent validity, the cost diary seems a valid method in establishing cost-of-illness in childhood anxiety disorders. PMID:18214667

  1. Bioinformatics approach for choosing the correct reference genes when studying gene expression in human keratinocytes.

    PubMed

    Beer, Lucian; Mlitz, Veronika; Gschwandtner, Maria; Berger, Tanja; Narzt, Marie-Sophie; Gruber, Florian; Brunner, Patrick M; Tschachler, Erwin; Mildner, Michael

    2015-10-01

    Reverse transcription polymerase chain reaction (qRT-PCR) has become a mainstay in many areas of skin research. To enable quantitative analysis, it is necessary to analyse expression of reference genes (RGs) for normalization of target gene expression. The selection of reliable RGs therefore has an important impact on the experimental outcome. In this study, we aimed to identify and validate the best suited RGs for qRT-PCR in human primary keratinocytes (KCs) over a broad range of experimental conditions using the novel bioinformatics tool 'RefGenes', which is based on a manually curated database of published microarray data. Expression of 6 RGs identified by RefGenes software and 12 commonly used RGs were validated by qRT-PCR. We assessed whether these 18 markers fulfilled the requirements for a valid RG by the comprehensive ranking of four bioinformatics tools and the coefficient of variation (CV). In an overall ranking, we found GUSB to be the most stably expressed RG, whereas the expression values of the commonly used RGs, GAPDH and B2M were significantly affected by varying experimental conditions. Our results identify RefGenes as a powerful tool for the identification of valid RGs and suggest GUSB as the most reliable RG for KCs.

  2. Societal burden of clinically anxious youth referred for treatment: a cost-of-illness study.

    PubMed

    Bodden, Denise H M; Dirksen, Carmen D; Bögels, Susan M

    2008-05-01

    A prevalence-based cost-of-illness study using a societal perspective was conducted to investigate the cost-of-illness in clinically anxious youth aged 8-18 in The Netherlands. Discriminant validity of the cost diary used was obtained by comparing costs of families with an anxious child (n = 118) to costs of families from the general population (n = 41). To examine the convergent validity, bottom-up acquired costs derived from cost diaries were compared to top-down acquired costs obtained from national registrations. Bottom-up acquired costs measured by means of cost diaries amounted to Euro 2,748 per family of a clinically referred anxious child per annum. Societal costs of families with clinically anxious children were almost 21 times as high compared to families from the general population. With respect to convergent validity, total health care costs using the bottom-up approach from clinically anxious children were quite comparable to those of top-down data of anxious children, although costs within the subcategories differed considerably. Clinical anxiety disorders in childhood cost the Dutch society more than 20 million euros a year. Based on results of discriminate and convergent validity, the cost diary seems a valid method in establishing cost-of-illness in childhood anxiety disorders.

  3. Study of superhydrophobic electrosprayed catalyst layers using a localized reference electrode technique

    NASA Astrophysics Data System (ADS)

    Chaparro, A. M.; Ferreira-Aparicio, P.; Folgado, M. A.; Brightman, E.; Hinds, G.

    2016-09-01

    The performance of electrosprayed cathode catalyst layers in a polymer electrolyte membrane fuel cell (PEMFC) is studied using a localized reference electrode technique. Single cells with an electrosprayed cathode catalyst layer show an increase of >20% in maximum power density under standard testing conditions, compared with identical cells assembled with a conventional, state-of-the-art, gas diffusion cathode. When operated at high current density (1.2 A cm-2) the electrosprayed catalyst layers show more homogeneous distribution of the localized cathode potential, with a standard deviation from inlet to outlet of <50 mV, compared with 79 mV for the conventional gas diffusion cathode. Higher performance and homogeneity of cell response is attributed to the superhydrophobic nature of the macroporous electrosprayed catalyst layer structure, which enhances the rate of expulsion of liquid water from the cathode. On the other hand, at low current densities (<0.5 A cm-2), the electrosprayed layers exhibit more heterogeneous distribution of cathode potential than the conventional cathodes; this behavior is attributed to less favorable kinetics for oxygen reduction in very hydrophobic catalyst layers. The optimum performance may be obtained with electrosprayed catalyst layers employing a high Pt/C catalyst ratio.

  4. Carboxylated nanodiamonds can be used as negative reference in in vitro nanogenotoxicity studies.

    PubMed

    Moche, H; Paget, V; Chevalier, D; Lorge, E; Claude, N; Girard, H A; Arnault, J C; Chevillard, S; Nesslany, F

    2017-02-06

    Nanodiamonds (NDs) are promising nanomaterials for biomedical applications. However, a few studies highlighted an in vitro genotoxic activity for detonation NDs, which was not evidenced in one of our previous work quantifying γ-H2Ax after 20 and 100 nm high-pressure high-temperature ND exposures of several cell lines. To confirm these results, in the present work, we investigated the genotoxicity of the same 20 and 100 nm NDs and added intermediate-sized NDs of 50 nm. Conventional in vitro genotoxicity tests were used, i.e., the in vitro micronucleus and comet assays that are recommended by the French National Agency for Medicines and Health Products Safety for the toxicological evaluation of nanomedicines. In vitro micronucleus and in vitro comet assays (standard and hOGG1-modified) were therefore performed in two human cell lines, the bronchial epithelial 16HBE14o- cells and the colon carcinoma T84 cells. Our results did not show any genotoxic activity, whatever the test, the cell line or the size of carboxylated NDs. Even though these in vitro results should be confirmed in vivo, they reinforce the potential interest of carboxylated NDs for biomedical applications or even as a negative reference nanoparticle in nanotoxicology. Copyright © 2017 John Wiley & Sons, Ltd.

  5. A Retrospective Study of Ectoparasitosis in Patients Referred to Imam Reza Hospital of Mashhad, Iran

    PubMed Central

    Berenji, Fariba; Marvi-Moghadam, Narges; Naghibozakerin Meibodi, Parisa

    2014-01-01

    This cross-sectional study was performed on all patients suspected to be suffering from ectoparasites who were referred to the parasitology laboratory of Imam Reza Hospital of Mashhad during 15 years (April 1995 to April 2010). All patients' data were collected from the questionnaires and then analyzed statistically. From 1814 suspected patients to be suffering from ectoparasites, 375 patients had scabies and, 99 suffer from pediculosis. The mean age of patients was 26/18 ± 17/68. The most common age of scabies was 10–19 (27/7%) and pediculosis 0–9(9/6%) (P value = 0.00). The highest incidence of pediculosis was in women (3.6%) and scabies in men (13.7%) (P value = 0.00). Pediculosis is more common in children (9/9%) and scabies in workers (32%)(P value = 0.00). Scabies and pediculosis were more prevalent in patients from Razavi Khorasan Province with 18.7% and 5%, respectively (P value = 0.08). PMID:24860806

  6. A retrospective study of ectoparasitosis in patients referred to Imam Reza Hospital of Mashhad, Iran.

    PubMed

    Berenji, Fariba; Marvi-Moghadam, Narges; Naghibozakerin Meibodi, Parisa

    2014-01-01

    This cross-sectional study was performed on all patients suspected to be suffering from ectoparasites who were referred to the parasitology laboratory of Imam Reza Hospital of Mashhad during 15 years (April 1995 to April 2010). All patients' data were collected from the questionnaires and then analyzed statistically. From 1814 suspected patients to be suffering from ectoparasites, 375 patients had scabies and, 99 suffer from pediculosis. The mean age of patients was 26/18 ± 17/68. The most common age of scabies was 10-19 (27/7%) and pediculosis 0-9(9/6%) (P value = 0.00). The highest incidence of pediculosis was in women (3.6%) and scabies in men (13.7%) (P value = 0.00). Pediculosis is more common in children (9/9%) and scabies in workers (32%)(P value = 0.00). Scabies and pediculosis were more prevalent in patients from Razavi Khorasan Province with 18.7% and 5%, respectively (P value = 0.08).

  7. A reference interval study for common biochemical analytes in Eastern Turkey: a comparison of a reference population with laboratory data mining

    PubMed Central

    Bakan, Ebubekir; Polat, Harun; Ozarda, Yesim; Ozturk, Nurinnisa; Baygutalp, Nurcan Kilic; Umudum, Fatma Zuhal; Bakan, Nuri

    2016-01-01

    Introduction The aim of this study was to define the reference intervals (RIs) in a Turkish population living in Northeast Turkey (Erzurum) for 34 analytes using direct and indirect methods. In the present study, the regional RIs obtained were compared with other RI studies, primarily the nationwide study performed in Turkey. Materials and methods For the direct method, 435 blood samples were collected from a healthy group of females (N = 218) and males (N = 217) aged between 18 and 65 years. The sera were analysed in Ataturk University hospital laboratory using Roche reagents and analysers for 34 analytes. The data from 1,366,948 records were used to calculate the indirect RIs using a modified Bhattacharya method. Results Significant gender-related differences were observed for 17 analytes. There were also some apparent differences between RIs derived from indirect and direct methods particularly in some analytes (e.g. gamma-glutamyltransferase, creatine kinase, LDL-cholesterol and iron). The RIs derived with the direct method for some, but not all, of the analytes were generally comparable with the RIs reported in the nationwide study and other previous studies in Turkey.There were large differences between RIs derived by the direct method and the expected values shown in the kit insert (e.g. aspartate aminotransferase, total-cholesterol, HDL-cholesterol, and vitamin B12). Conclusions These data provide region-specific RIs for 34 analytes determined by the direct and indirect methods. The observed differences in RIs between previous studies could be related to nutritional status and environmental factors. PMID:27346966

  8. Physical design study of the CEPC booster

    NASA Astrophysics Data System (ADS)

    Zhang, Chuang

    2016-09-01

    A physical design study of the Circular Electron-Positron Collider (CEPC) booster is reported. The booster provides 120 GeV electron and positron beams for the CEPC collider with top-up injection. The booster is mounted above the collider in the same tunnel. To save cost, the energy of the linac injector for the booster is chosen as 6 GeV, corresponding to a magnetic field of 30.7 Gs. In this paper, the booster lattice is described and optimization of the cell length is discussed. A novel scheme of bypass near the detector of the collider is designed. The extremely low magnetic field caused by low injection energy is studied, and a new ideal of wiggling bands is proposed to mitigate the low-field problem. Beam transfer and injection from the linac to the booster are considered.

  9. DU-AGG pilot plant design study

    SciTech Connect

    Lessing, P.A.; Gillman, H.

    1996-07-01

    The Idaho National Engineering Laboratory (INEL) is developing new methods to produce high-density aggregate (artificial rock) primarily consisting of depleted uranium oxide. The objective is to develop a low-cost method whereby uranium oxide powder (UO[sub 2], U[sub 3]O[sub ]8, or UO[sub 3]) can be processed to produce high-density aggregate pieces (DU-AGG) having physical properties suitable for disposal in low-level radioactive disposal facilities or for use as a component of high-density concrete used as shielding for radioactive materials. A commercial company, G-M Systems, conducted a design study for a manufacturing pilot plant to process DU-AGG. The results of that study are included and summarized in this report. Also explained are design considerations, equipment capacities, the equipment list, system operation, layout of equipment in the plant, cost estimates, and the proposed plan and schedule.

  10. Study designs in thoracic surgery research

    PubMed Central

    Terzi, Alberto; Bertolaccini, Luca

    2016-01-01

    In this short review, we’ll try to specify the differences between evaluation procedures of groups of data, as they present to researchers. The way and time data are gathered defines the type of study is going to shape. When we observe a cluster of data without deliberately interfering with the process we mean to evaluate, we perform an observational study. Observational studies are the main topic of this issue. Upon the contrary, experimental studies imply the direct action of the observer on the study population in order to define the role of a given exposure. The topic of experimental study design will be covered in another issue of this series. PMID:27747029

  11. Electrostatic camera system functional design study

    NASA Technical Reports Server (NTRS)

    Botticelli, R. A.; Cook, F. J.; Moore, R. F.

    1972-01-01

    A functional design study for an electrostatic camera system for application to planetary missions is presented. The electrostatic camera can produce and store a large number of pictures and provide for transmission of the stored information at arbitrary times after exposure. Preliminary configuration drawings and circuit diagrams for the system are illustrated. The camera system's size, weight, power consumption, and performance are characterized. Tradeoffs between system weight, power, and storage capacity are identified.

  12. Preliminary shuttle structural dynamics modeling design study

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design and development of a structural dynamics model of the space shuttle are discussed. The model provides for early study of structural dynamics problems, permits evaluation of the accuracy of the structural and hydroelastic analysis methods used on test vehicles, and provides for efficiently evaluating potential cost savings in structural dynamic testing techniques. The discussion is developed around the modes in which major input forces and responses occur and the significant structural details in these modes.

  13. Selection of suitable reference genes for gene expression studies in Staphylococcus capitis during growth under erythromycin stress.

    PubMed

    Cui, Bintao; Smooker, Peter M; Rouch, Duncan A; Deighton, Margaret A

    2016-08-01

    Accurate and reproducible measurement of gene transcription requires appropriate reference genes, which are stably expressed under different experimental conditions to provide normalization. Staphylococcus capitis is a human pathogen that produces biofilm under stress, such as imposed by antimicrobial agents. In this study, a set of five commonly used staphylococcal reference genes (gyrB, sodA, recA, tuf and rpoB) were systematically evaluated in two clinical isolates of Staphylococcus capitis (S. capitis subspecies urealyticus and capitis, respectively) under erythromycin stress in mid-log and stationary phases. Two public software programs (geNorm and NormFinder) and two manual calculation methods, reference residue normalization (RRN) and relative quantitative (RQ), were applied. The potential reference genes selected by the four algorithms were further validated by comparing the expression of a well-studied biofilm gene (icaA) with phenotypic biofilm formation in S. capitis under four different experimental conditions. The four methods differed considerably in their ability to predict the most suitable reference gene or gene combination for comparing icaA expression under different conditions. Under the conditions used here, the RQ method provided better selection of reference genes than the other three algorithms; however, this finding needs to be confirmed with a larger number of isolates. This study reinforces the need to assess the stability of reference genes for analysis of target gene expression under different conditions and the use of more than one algorithm in such studies. Although this work was conducted using a specific human pathogen, it emphasizes the importance of selecting suitable reference genes for accurate normalization of gene expression more generally.

  14. A Numerical Climate Observing Network Design Study

    NASA Technical Reports Server (NTRS)

    Stammer, Detlef

    2003-01-01

    This project was concerned with three related questions of an optimal design of a climate observing system: 1. The spatial sampling characteristics required from an ARGO system. 2. The degree to which surface observations from ARGO can be used to calibrate and test satellite remote sensing observations of sea surface salinity (SSS) as it is anticipated now. 3. The more general design of an climate observing system as it is required in the near future for CLIVAR in the Atlantic. An important question in implementing an observing system is that of the sampling density required to observe climate-related variations in the ocean. For that purpose this project was concerned with the sampling requirements for the ARGO float system, but investigated also other elements of a climate observing system. As part of this project we studied the horizontal and vertical sampling characteristics of a global ARGO system which is required to make it fully complementary to altimeter data with the goal to capture climate related variations on large spatial scales (less thanAttachment: 1000 km). We addressed this question in the framework of a numerical model study in the North Atlantic with an 1/6 horizontal resolution. The advantage of a numerical design study is the knowledge of the full model state. Sampled by a synthetic float array, model results will therefore allow to test and improve existing deployment strategies with the goal to make the system as optimal and cost-efficient as possible. Attachment: "Optimal observations for variational data assimilation".

  15. Microgravity isolation system design: A case study

    NASA Technical Reports Server (NTRS)

    Hampton, R. D.; Knospe, C. R.; Allaire, P. E.; Grodsinsky, C. M.

    1994-01-01

    Many acceleration-sensitive, microgravity science experiments will require active vibration isolation from manned orbiters on which they will be mounted. The isolation problem, especially in the case of a tethered payload, is a complex three-dimensional one that is best suited to modern-control design methods. In this paper, extended H(sub 2) synthesis is used to design an active isolator (i.e., controller) for a realistic single-input-multiple-output (SIMO) microgravity vibration isolation problem. Complex mu-analysis methods are used to analyze the isolation system with respect to sensor, actuator, and umbilical uncertainties. The paper fully discusses the design process employed and the insights gained. This design case study provides a practical approach for isolation problems of greater complexity. Issues addressed include a physically intuitive state-space description of the system, disturbance and noise filters, filters for frequency weighting, and uncertainty models. The controlled system satisfies all the performance specifications and is robust with respect to model uncertainties.

  16. MRF study. Part 2: Antenna design

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An assessment of the practical feasibility of the design and construction of an antenna to meet the requirements of a conceptual radar system is studied. Both the subscale antenna, nominally 5 by 4 meters in dimensions, and the full scale antenna, taken as nominally 18 by 4 meters in size, were considered. The examination of feasibility was from electrical, mechanical, and thermal standpoints. Fundamental, electrical, microwave design questions applying to both the subscale and the full scale antennas were considered in greater detail than questions of mechanical configuration and thermal design. Layouts were made in the development of preliminary configurations, along with a deployment method, for the subscale antenna in conjunction with an antenna cluster for alternate arrangements of the three pallet configuration. Implementation of the array and support structure and attachment of the array to the support and thermal provision was considered. Results show that a microwave design of antennas that incorporate traveling wave arrays can be effected with the beam scanned to 45 degrees in elevation without occurrence of higher order beams.

  17. Reference ranges and determinants of total hCG levels during pregnancy: the Generation R Study.

    PubMed

    Korevaar, Tim I M; Steegers, Eric A P; de Rijke, Yolanda B; Schalekamp-Timmermans, Sarah; Visser, W Edward; Hofman, Albert; Jaddoe, Vincent W V; Tiemeier, Henning; Visser, Theo J; Medici, Marco; Peeters, Robin P

    2015-09-01

    Human chorionic gonadotropin (hCG) is a pregnancy hormone secreted by the placental synctiotrophoblast cell layer that has been linked to fetal growth and various placental, uterine and fetal functions. In order to investigate the effects of hCG on clinical endpoints, knowledge on reference range (RR) methodology and determinants of gestational hCG levels is crucial. Moreover, a better understanding of gestational hCG physiology can improve current screening programs and future clinical management. Serum total hCG levels were determined in 8195 women participating in the Generation R Study. Gestational age specific RRs using 'ultrasound derived gestational age' (US RRs) were calculated and compared with 'last menstrual period derived gestational age' (LMP RRs) and a model-based RR. We also investigated which pregnancy characteristics were associated with hCG levels. Compared to the US RRs, the LMP RRs were lower, most notably for the median and lower limit levels. No considerable differences were found between RRs calculated in the general population or in uncomplicated pregnancies only. Maternal smoking, BMI, parity, ethnicity, fetal gender, placental weight and hyperemesis gravidarum symptoms were associated with total hCG. We provide gestational RRs for total hCG and show that total hCG values and RR cut-offs during pregnancy vary depending on pregnancy dating methodology. This is likely due to the influence of hCG on embryonic growth, suggesting that ultrasound based pregnancy dating might be less reliable in women with high/low hCG levels. Furthermore, we identify different pregnancy characteristics that influence total hCG levels considerably and should therefore be accounted for in clinical studies.

  18. A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive.

    PubMed

    Castillo, Richard; Castillo, Edward; Fuentes, David; Ahmad, Moiz; Wood, Abbie M; Ludwig, Michelle S; Guerrero, Thomas

    2013-05-07

    Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts.

  19. Selection and validation of reference genes for transcript normalization in gene expression studies in Catharanthus roseus.

    PubMed

    Pollier, Jacob; Vanden Bossche, Robin; Rischer, Heiko; Goossens, Alain

    2014-10-01

    Quantitative Real-Time PCR (qPCR), a sensitive and commonly used technique for gene expression analysis, requires stably expressed reference genes for normalization of gene expression. Up to now, only one reference gene for qPCR analysis, corresponding to 40S Ribosomal protein S9 (RPS9), was available for the medicinal plant Catharanthus roseus, the only source of the commercial anticancer drugs vinblastine and vincristine. Here, we screened for additional reference genes for this plant species by mining C. roseus RNA-Seq data for orthologs of 22 genes known to be stably expressed in Arabidopsis thaliana and qualified as superior reference genes for this model plant species. Based on this, eight candidate C. roseus reference genes were identified and, together with RPS9, evaluated by performing qPCR on a series of different C. roseus explants and tissue cultures. NormFinder, geNorm and BestKeeper analyses of the resulting qPCR data revealed that the orthologs of At2g28390 (SAND family protein, SAND), At2g32170 (N2227-like family protein, N2227) and At4g26410 (Expressed protein, EXP) had the highest expression stability across the different C. roseus samples and are superior as reference genes as compared to the traditionally used RPS9. Analysis of publicly available C. roseus RNA-Seq data confirmed the expression stability of SAND and N2227, underscoring their value as reference genes for C. roseus qPCR analysis.

  20. Selection of suitable reference genes for gene expression studies in normal human ovarian tissues, borderline ovarian tumours and ovarian cancer.

    PubMed

    Ofinran, Olumide; Bose, Ujjal; Hay, Daniel; Abdul, Summi; Tufatelli, Cristina; Khan, Raheela

    2016-12-01

    The use of reference genes is the most common method of controlling the variation in mRNA expression during quantitative polymerase chain reaction, although the use of traditional reference genes, such as β‑actin, glyceraldehyde‑3‑phosphate dehydrogenase or 18S ribosomal RNA, without validation occasionally leads to unreliable results. Therefore, the present study aimed to evaluate a set of five commonly used reference genes to determine the most suitable for gene expression studies in normal ovarian tissues, borderline ovarian and ovarian cancer tissues. The expression stabilities of these genes were ranked using two gene stability algorithms, geNorm and NormFinder. Using geNorm, the two best reference genes in ovarian cancer were β‑glucuronidase and β‑actin. Hypoxanthine phosphoribosyltransferase‑1 and β‑glucuronidase were the most stable in ovarian borderline tumours, and hypoxanthine phosphoribosyltransferase‑1 and glyceraldehyde‑3‑phosphate dehydrogenase were the most stable in normal ovarian tissues. NormFinder ranked β‑actin the most stable in ovarian cancer, and the best combination of two genes was β‑glucuronidase and β‑actin. In borderline tumours, hypoxanthine phosphoribosyltransferase‑1 was identified as the most stable, and the best combination was hypoxanthine phosphoribosyltransferase‑1 and β‑glucuronidase. In normal ovarian tissues, β‑glucuronidase was recommended as the optimum reference gene, and the most optimum pair of reference genes was hypoxanthine phosphoribosyltransferase‑1 and β‑actin. To the best of our knowledge, this is the first study to investigate the selection of a set of reference genes for normalisation in quantitative polymerase chain reactions in different ovarian tissues, and therefore it is recommended that β‑glucuronidase, β‑actin and hypoxanthine phosphoribosyltransferase‑1 are the most suitable reference genes for such analyses.

  1. AFE ion mass spectrometer design study

    NASA Technical Reports Server (NTRS)

    Wright, Willie

    1989-01-01

    This final technical report covers the activities engaged in by the University of Texas at Dallas, Center for Space Sciences in conjunction with the NASA Langley Research Center, Systems Engineering Division in design studies directed towards defining a suitable ion mass spectrometer to determine the plasma parameter around the Aeroassisted Flight Experiment vehicle during passage through the earth's upper atmosphere. Additional studies relate to the use of a Langmuir probe to measure windward ion/electron concentrations and temperatures. Selected instrument inlet subsystems were tested in the NASA Ames Arc-Jet Facility.

  2. Design study of a flexible diaphragm

    SciTech Connect

    Whatley, M E; Morgan, J G

    1982-10-01

    A design study was made to meet the requirements for a diaphragm for a rotary seal at the discharge end of the Consolidated Fuel Reprocessing Program`s prototypic voloxidizer. Using a computer program called NEPSAP, the study examined thickness, outer radius, corrugation wavelength and corrugation amplitude as variables, and established the general effect of each on stiffness and stresses. The result comprises a basis for the selection of diaphragms for similar applications. Limited experimental measurements of stress validate the stress values calculated by NEPSAP.

  3. Contrasting genetic architectures in different mouse reference populations used for studying complex traits

    PubMed Central

    Buchner, David A.; Nadeau, Joseph H.

    2015-01-01

    Quantitative trait loci (QTLs) are being used to study genetic networks, protein functions, and systems properties that underlie phenotypic variation and disease risk in humans, model organisms, agricultural species, and natural populations. The challenges are many, beginning with the seemingly simple tasks of mapping QTLs and identifying their underlying genetic determinants. Various specialized resources have been developed to study complex traits in many model organisms. In the mouse, remarkably different pictures of genetic architectures are emerging. Chromosome Substitution Strains (CSSs) reveal many QTLs, large phenotypic effects, pervasive epistasis, and readily identified genetic variants. In contrast, other resources as well as genome-wide association studies (GWAS) in humans and other species reveal genetic architectures dominated with a relatively modest number of QTLs that have small individual and combined phenotypic effects. These contrasting architectures are the result of intrinsic differences in the study designs underlying different resources. The CSSs examine context-dependent phenotypic effects independently among individual genotypes, whereas with GWAS and other mouse resources, the average effect of each QTL is assessed among many individuals with heterogeneous genetic backgrounds. We argue that variation of genetic architectures among individuals is as important as population averages. Each of these important resources has particular merits and specific applications for these individual and population perspectives. Collectively, these resources together with high-throughput genotyping, sequencing and genetic engineering technologies, and information repositories highlight the power of the mouse for genetic, functional, and systems studies of complex traits and disease models. PMID:25953951

  4. Children referred for specialist care: a nationwide study in Dutch general practice.

    PubMed Central

    van Suijlekom-Smit, L W; Bruijnzeels, M A; van der Wouden, J C; van der Velden, J; Visser, H K; Dokter, H J

    1997-01-01

    BACKGROUND: Insight into referral patterns provides general practitioners (GPs) and specialists with a frame of reference for their own work and enables assessment of the need for secondary care. Only approximate information is available. AIM: To determine how often, to which specialties and for what conditions children in different age groups are referred, as well as how often a condition is referred given the incidence in general practice. METHOD: From data of the Dutch National Survey of Morbidity and Interventions in General Practice, 63,753 new referrals (acute and non-acute) were analysed for children (0-14 years) from 103 participating practices (161 GPs) who registered. Practices were divided into four groups. Each group of practices participated for three consecutive months covering a whole year altogether. We calculated referral rates per 1000 children per year and referability rates per 100 episodes, which quantifies the a priori chance of a condition being referred for specialist care. RESULTS: The referral rate varied by age from 231 for children under 1 year old to 119 for those aged 10-14 years (mean 159). The specialties mainly involved were ENT, paediatrics, surgery, ophthalmology, dermatology and orthopaedics. Referrals in the first year of life were most frequently to paediatricians (123); among older children the referral rate to paediatricians decreased (mean 36). Referrals to ENT specialists were seen particularly in the age groups 1-4 (71) and 5-9 (53). For surgery, the referral rate increased by age from 19 to 34. Differences between boys and girls were small, except for surgery. The highest referral rates were for problems in the International Classification of Primary Care (ICPC) chapters: respiratory (28); musculoskeletal (25); ear (24) and eye (21). Referability rates were, in general, low for conditions referred to paediatrics and dermatology and high for surgery and ophthalmology. The variation in problems presented to each specialty

  5. Reference genes for normalization of gene expression studies in human osteoarthritic articular cartilage

    PubMed Central

    Pombo-Suarez, Manuel; Calaza, Manuel; Gomez-Reino, Juan J; Gonzalez, Antonio

    2008-01-01

    Background Assessment of gene expression is an important component of osteoarthritis (OA) research, greatly improved by the development of quantitative real-time PCR (qPCR). This technique requires normalization for precise results, yet no suitable reference genes have been identified in human articular cartilage. We have examined ten well-known reference genes to determine the most adequate for this application. Results Analyses of expression stability in cartilage from 10 patients with hip OA, 8 patients with knee OA and 10 controls without OA were done with classical statistical tests and the software programs geNorm and NormFinder. Results from the three methods of analysis were broadly concordant. Some of the commonly used reference genes, GAPDH, ACTB and 18S RNA, performed poorly in our analysis. In contrast, the rarely used TBP, RPL13A and B2M genes were the best. It was necessary to use together several of these three genes to obtain the best results. The specific combination depended, to some extent, on the type of samples being compared. Conclusion Our results provide a satisfactory set of previously unused reference genes for qPCR in hip and knee OA This confirms the need to evaluate the suitability of reference genes in every tissue and experimental situation before starting the quantitative assessment of gene expression by qPCR. PMID:18226276

  6. Evaluation of Clostridium ljungdahlii DSM 13528 reference genes in gene expression studies by qRT-PCR.

    PubMed

    Liu, Juanjuan; Tan, Yang; Yang, Xiaohong; Chen, Xiaohua; Li, Fuli

    2013-10-01

    Clostridium ljungdahlii DSM 13528 is a promising platform organism for biofuel production from syngas. Gene expression analysis permits a better understanding of the important molecular biological characteristics of this organism, such as carbon fixation and solvent adaptation. Normalization is a prerequisite for accurate gene expression analysis, but until now, no valid reference genes have been proposed for quantitative real-time polymerase chain reaction (qRT-PCR) analysis of C. ljungdahlii DSM 13528. In this study, seven candidate reference genes (gyrA, rho, fotl, rpoA, gukl, recA, 16S rRNA) were selected for qRT-PCR quantification of their expression levels in various culture conditions that corresponded to different carbon sources and stresses. Two analytical programs, geNorm and NormFinder, were used to evaluate reference gene stability. The results showed that gyrA, rho and fotl exhibited the most stable expression levels across all tested samples and can be confidently used as reference genes to normalize the transcriptional data of target genes in qRT-PCR analyses of C. ljungdahlii DSM 13528. This study presents the first attempt to explore the validity of candidate reference genes and provide a set of valid reference genes for normalizing C. ljungdahlii DSM 13528 target gene expression and transcriptome analysis.

  7. Evaluation of Reference Genes for RT-qPCR Studies in the Seagrass Zostera muelleri Exposed to Light Limitation

    PubMed Central

    Schliep, M.; Pernice, M.; Sinutok, S.; Bryant, C. V.; York, P. H.; Rasheed, M. A.; Ralph, P. J.

    2015-01-01

    Seagrass meadows are threatened by coastal development and global change. In the face of these pressures, molecular techniques such as reverse transcription quantitative real-time PCR (RT-qPCR) have great potential to improve management of these ecosystems by allowing early detection of chronic stress. In RT-qPCR, the expression levels of target genes are estimated on the basis of reference genes, in order to control for RNA variations. Although determination of suitable reference genes is critical for RT-qPCR studies, reports on the evaluation of reference genes are still absent for the major Australian species Zostera muelleri subsp. capricorni (Z. muelleri). Here, we used three different software (geNorm, NormFinder and Bestkeeper) to evaluate ten widely used reference genes according to their expression stability in Z. muelleri exposed to light limitation. We then combined results from different software and used a consensus rank of four best reference genes to validate regulation in Photosystem I reaction center subunit IV B and Heat Stress Transcription factor A- gene expression in Z. muelleri under light limitation. This study provides the first comprehensive list of reference genes in Z. muelleri and demonstrates RT-qPCR as an effective tool to identify early responses to light limitation in seagrass. PMID:26592440

  8. A Reference-Dependent Regret Model for Deterministic Trade-off Studies

    SciTech Connect

    Kujawski, Edouard

    2005-02-25

    Today's typical multi-criteria decision analysis is based on classical expected utility theory that assumes a mythical ''Rational Individual'' immune to psychological influences such as anticipated regret. It is therefore in conflict with rational individuals who trade-off some benefits and forgo the alternative with the highest total classical utility for a more balanced alternative in order to reduce their levels of anticipated regret. This paper focuses on decision making under certainty. It presents a reference-dependent regret model (RDRM) in which the level of regret that an individual experiences depends on the absolute values rather than the differences of the utilities of the chosen and forgone alternatives. The RDRM best choice may differ from the conventional linear additive utility model, the analytic hierarchy process, and the regret theory of Bell and Loomes and Sugden. Examples are presented that indicate that RDRM is the better predictive descriptor for decision making under certainty. RDRM satisfies transitivity of the alternatives under pairwise comparisons and models rank reversal consistent with observed reasonable choices under dynamic or distinct situations. Like regret theory, the RDRM utilities of all the alternatives under consideration are interrelated. For complex trade-off studies regret is incorporated as an element of a cost-utility-regret analysis that characterizes each alternative in terms of its monetary cost, an aggregate performance utility, and a regret value. This provides decision makers adequate information to compare the alternatives and depending on their values they may trade-off some performance and/or cost to avoid high levels of regret. The result is a well-balanced alternative often preferred by reasonable decision makers to the optimal choice of classical multi-attribute utility analysis. The model can readily be extended to incorporate rejoicing to suit decision makers who seek it. The approach is illustrated using a

  9. Impact of the VLBA on reference frames and earth orientation studies

    NASA Astrophysics Data System (ADS)

    Gordon, David

    2016-09-01

    The geodetic VLBI community began using VLBA antennas in 1989 for geodesy and astrometry. We examine how usage of the VLBA has improved the celestial reference frame, the terrestrial reference frame, and Earth orientation parameters. Without the VLBA, ICRF2 would have had only 1011 sources instead of 3414. ICRF3 will contain at least 4121 sources, with approximately 70 % or more coming exclusively from VLBA astrometry and geodesy sessions. The terrestrial reference frame is also more stable and precise due to VLBA geodesy sessions. Approximately two dozen geodesy stations that have participated in VLBA sessions show average position formal errors that are ˜ 13-14 % better in the horizontal components and ˜ 5 % better in the vertical component than would be expected solely from the increased number of observations. Also the Earth orientation parameters obtained from the RDV sessions represent the most accurate EOP series of any of the long-term VLBI session types.

  10. Reference gene alternatives to Gapdh in rodent and human heart failure gene expression studies

    PubMed Central

    2010-01-01

    Background Quantitative real-time RT-PCR (RT-qPCR) is a highly sensitive method for mRNA quantification, but requires invariant expression of the chosen reference gene(s). In pathological myocardium, there is limited information on suitable reference genes other than the commonly used Gapdh mRNA and 18S ribosomal RNA. Our aim was to evaluate and identify suitable reference genes in human failing myocardium, in rat and mouse post-myocardial infarction (post-MI) heart failure and across developmental stages in fetal and neonatal rat myocardium. Results The abundance of Arbp, Rpl32, Rpl4, Tbp, Polr2a, Hprt1, Pgk1, Ppia and Gapdh mRNA and 18S ribosomal RNA in myocardial samples was quantified by RT-qPCR. The expression variability of these transcripts was evaluated by the geNorm and Normfinder algorithms and by a variance component analysis method. Biological variability was a greater contributor to sample variability than either repeated reverse transcription or PCR reactions. Conclusions The most stable reference genes were Rpl32, Gapdh and Polr2a in mouse post-infarction heart failure, Polr2a, Rpl32 and Tbp in rat post-infarction heart failure and Rpl32 and Pgk1 in human heart failure (ischemic disease and cardiomyopathy). The overall most stable reference genes across all three species was Rpl32 and Polr2a. In rat myocardium, all reference genes tested showed substantial variation with developmental stage, with Rpl4 as was most stable among the tested genes. PMID:20331858

  11. A combined strategy of "in silico" transcriptome analysis and web search engine optimization allows an agile identification of reference genes suitable for normalization in gene expression studies.

    PubMed

    Faccioli, Primetta; Ciceri, Gian Paolo; Provero, Paolo; Stanca, Antonio Michele; Morcia, Caterina; Terzi, Valeria

    2007-03-01

    Traditionally housekeeping genes have been employed as endogenous reference (internal control) genes for normalization in gene expression studies. Since the utilization of single housekeepers cannot assure an unbiased result, new normalization methods involving multiple housekeeping genes and normalizing using their mean expression have been recently proposed. Moreover, since a gold standard gene suitable for every experimental condition does not exist, it is also necessary to validate the expression stability of every putative control gene on the specific requirements of the planned experiment. As a consequence, finding a good set of reference genes is for sure a non-trivial problem requiring quite a lot of lab-based experimental testing. In this work we identified novel candidate barley reference genes suitable for normalization in gene expression studies. An advanced web search approach aimed to collect, from publicly available web resources, the most interesting information regarding the expression profiling of candidate housekeepers on a specific experimental basis has been set up and applied, as an example, on stress conditions. A complementary lab-based analysis has been carried out to verify the expression profile of the selected genes in different tissues and during heat shock response. This combined dry/wet approach can be applied to any species and physiological condition of interest and can be considered very helpful to identify putative reference genes to be shortlisted every time a new experimental design has to be set up.

  12. VXIbus data collection system -- A design study

    SciTech Connect

    Hacker, U.; Richter, B.; Weinert, A.; Arlt, R.; Lewis, W.; Swinhoe, M.

    1995-12-31

    The German support program has sponsored the work to investigate the VXIbus as integration platform for safeguards instrumentation. This paper will cover the analysis of the user requirements for a VXIbus based monitoring system for integrated safeguards -- primarily for reliable unattended in-field collection of large amounts of data. The goal is to develop a suitable system architecture. The design of the system makes use of the VXIbus standard as the selected hardware platform Based upon the requirement analysis and the overriding need for high reliability and robustness, a systematic investigation of different operating system options, as well as development and integration tools will be considered. For the software implementation cycle high and low level programming tools are required. The identification of the constraints for the programming platform and the tool selection will be presented. Both the strategic approach, the rules for analysis and design work as well as the executive components for the support of the implementation and production cycle are given. Here all the conditions for reliable, unattended and integrated safeguards monitoring systems will be addressed. The definition of the basic and advanced design principles are covered. The paper discusses the results of a study on a system produced to demonstrate a high data rate timer/counter application.

  13. Advanced Subsonic Airplane Design and Economic Studies

    NASA Technical Reports Server (NTRS)

    Liebeck, Robert H.; Andrastek, Donald A.; Chau, Johnny; Girvin, Raquel; Lyon, Roger; Rawdon, Blaine K.; Scott, Paul W.; Wright, Robert A.

    1995-01-01

    A study was made to examine the effect of advanced technology engines on the performance of subsonic airplanes and provide a vision of the potential which these advanced engines offered. The year 2005 was selected as the entry-into-service (EIS) date for engine/airframe combination. A set of four airplane classes (passenger and design range combinations) that were envisioned to span the needs for the 2005 EIS period were defined. The airframes for all classes were designed and sized using 2005 EIS advanced technology. Two airplanes were designed and sized for each class: one using current technology (1995) engines to provide a baseline, and one using advanced technology (2005) engines. The resulting engine/airframe combinations were compared and evaluated on the basis on sensitivity to basic engine performance parameters (e.g. SFC and engine weight) as well as DOC+I. The advanced technology engines provided significant reductions in fuel burn, weight, and wing area. Average values were as follows: reduction in fuel burn = 18%, reduction in wing area = 7%, and reduction in TOGW = 9%. Average DOC+I reduction was 3.5% using the pricing model based on payload-range index and 5% using the pricing model based on airframe weight. Noise and emissions were not considered.

  14. A Stable Geodetic Reference Frame within the COCONET Footprint to Enable High-Accuracy Ground Deformation Study

    NASA Astrophysics Data System (ADS)

    Liu, H.; Wang, G.; Yu, J.

    2014-12-01

    COCONET(Continuously Operating Caribbean GPS Observational Network) is a multidisciplinary research infrastructure focused on improving the ability to understand, predict, and prepare for multiple natural hazards in the Caribbean, Central America, and Northern Andes. GPS data alone cannot provide accurate ground deformation information over time and space. A precise regional reference frame is needed in interpolating GPS observations to address regional and local ground deformations. Failure to use a precise reference frame would cause unintended negative consequences. The mainly purpose of this study is to establish a stable geodetic reference frame within the COCONet footprint (abbreviated as "COCONet-RF") and to provide positional time series and velocities (relative to COCONet-RF) of all permanent GPS stations within the COCONet footprint to the public. The GIPSY software package was used to calculate position within IGS08. The local reference frame was realized by a 14-parameter Helmert transformation technique. It will be periodically updated in order to synchronize with the update of the IGS reference frame. This stable COCONer-RF would provide a higher accuracy geodetic infrastructure for delineating the magnitude and spatial and temporal variations of ground deformations associated with landslides, faulting, subsidence, and volcanoes. Researchers who are not familiar with GPS data processing and reference transformation will be able to directly integrate COCONET products into their specific research.

  15. Protecting count queries in study design

    PubMed Central

    Sarwate, Anand D; Boxwala, Aziz A

    2012-01-01

    Objective Today's clinical research institutions provide tools for researchers to query their data warehouses for counts of patients. To protect patient privacy, counts are perturbed before reporting; this compromises their utility for increased privacy. The goal of this study is to extend current query answer systems to guarantee a quantifiable level of privacy and allow users to tailor perturbations to maximize the usefulness according to their needs. Methods A perturbation mechanism was designed in which users are given options with respect to scale and direction of the perturbation. The mechanism translates the true count, user preferences, and a privacy level within administrator-specified bounds into a probability distribution from which the perturbed count is drawn. Results Users can significantly impact the scale and direction of the count perturbation and can receive more accurate final cohort estimates. Strong and semantically meaningful differential privacy is guaranteed, providing for a unified privacy accounting system that can support role-based trust levels. This study provides an open source web-enabled tool to investigate visually and numerically the interaction between system parameters, including required privacy level and user preference settings. Conclusions Quantifying privacy allows system administrators to provide users with a privacy budget and to monitor its expenditure, enabling users to control the inevitable loss of utility. While current measures of privacy are conservative, this system can take advantage of future advances in privacy measurement. The system provides new ways of trading off privacy and utility that are not provided in current study design systems. PMID:22511018

  16. Design Study: Rocket Based MHD Generator

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This report addresses the technical feasibility and design of a rocket based MHD generator using a sub-scale LOx/RP rocket motor. The design study was constrained by assuming the generator must function within the performance and structural limits of an existing magnet and by assuming realistic limits on (1) the axial electric field, (2) the Hall parameter, (3) current density, and (4) heat flux (given the criteria of heat sink operation). The major results of the work are summarized as follows: (1) A Faraday type of generator with rectangular cross section is designed to operate with a combustor pressure of 300 psi. Based on a magnetic field strength of 1.5 Tesla, the electrical power output from this generator is estimated to be 54.2 KW with potassium seed (weight fraction 3.74%) and 92 KW with cesium seed (weight fraction 9.66%). The former corresponds to a enthalpy extraction ratio of 2.36% while that for the latter is 4.16%; (2) A conceptual design of the Faraday MHD channel is proposed, based on a maximum operating time of 10 to 15 seconds. This concept utilizes a phenolic back wall for inserting the electrodes and inter-electrode insulators. Copper electrode and aluminum oxide insulator are suggested for this channel; and (3) A testing configuration for the sub-scale rocket based MHD system is proposed. An estimate of performance of an ideal rocket based MHD accelerator is performed. With a current density constraint of 5 Amps/cm(exp 2) and a conductivity of 30 Siemens/m, the push power density can be 250, 431, and 750 MW/m(sup 3) when the induced voltage uB have values of 5, 10, and 15 KV/m, respectively.

  17. Single Mode Optical Waveguide Design Study.

    DTIC Science & Technology

    1981-11-23

    AD-I7g62 CORNING GLASS WORKS NY FIG 20/6 ADA0 21 SINGLE MODE OPTICAL WAVEGUIDE DESIGN STUDY.(U) NOV 81 V A BHAGAVATJLA. D B KECK, R A WESTWIG N00173...Ralph A. Westwig Corning Glass Works ’ 1 / Research and Development-Division Sullivan Park Corning, New York Th document ha bern c -yro vd Spubc rlea...Authors: Venkata A. Bhagavatula Donald B. Keck Ralph A. Westwig Corning Glass Works Research and Development Division Sullivan Park Corning, New York 11

  18. SP-100 radiator design trade study

    NASA Technical Reports Server (NTRS)

    Ewell, Richard

    1992-01-01

    A design trade study of the SP-100 heat rejection subsystem (HRSS) was made. A system code was used to evaluate the sensitivity of the HRSS mass and performance to changes. Variations in heat pipe diameter and cross-section, fin length and thickness, armor thickness, and overall configuration and materials were evaluated. The analysis indicates that the minimum system mass occurs for the case with many small diameter heat pipes, with ducting that maximizes the fraction of the heat pipe evaporator perimeter in contact with it.

  19. Genome wide association study using the ICARDA Lentil Reference set and agronomic data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentil (Lens culinaris Medik.) is the world’s fifth most important pulse crop. It is self-pollinated diploid (2n=14) and has a relatively large genome size of approximately 4Gb. Next generation sequencing (NGS) technology was used to genotype the ICARDA Lentil Reference set using the two-enzyme (Pst...

  20. The Impact of First Careers on "Second Career" Academic Reference Librarians: A Pilot Study.

    ERIC Educational Resources Information Center

    Whitten, Penelope A.; Nozero, Victoria A.

    1997-01-01

    A pilot survey of academic reference librarians in Nevada determined that 74% of those identified as second-career librarians cited prior work experience as influencing their present approach to work. Effects noted were service orientation, subject expertise, teaching skills, "information provider" philosophy, empathy, and interviewing…

  1. Weeding Is Not Just for Gardeners: A Case Study on Weeding a Reference Collection

    ERIC Educational Resources Information Center

    Lee, Marta

    2009-01-01

    Weeding a reference collection can be time consuming, a thankless job, and an endless task. It is a dusty job and can add to the librarian's workload. Weeding the collection can add to its currency and usability; plus it removes outdated materials. Periodically weeding allows librarians to remember what is in the collection and what can be removed…

  2. A study of production of radioactive environmental reference materials used for proficiency testing program in Taiwan.

    PubMed

    Peng, En-Chi; Wang, Jeng-Jong

    2013-11-01

    To realise radioactive environmental reference materials in Taiwan, seven environmental materials of soil, water, vegetation, meat, airborne particles (filter paper), milk and mushroom samples that are frequently encountered were used to establish the preparation of the reference materials. These seven environmental materials were collected, checked for freedom from radioactivity and prepared according to their properties. The preparation was carried out by using activity about 10-100 times that of the minimum detectable activity (MDA) in routine measurements in the radioactive standard used to spike the inactive material and this standard is traceable to national ionising radioactivity standards (TAF, 2004). To demonstrate sample traceability to the added standard, each sample was carefully measured and its uncertainty evaluated. Based on the recommendations of ISO Guide 35 for evaluation of reference materials and with the above assessment and verification procedures, the uncertainties (k=1) of the spike activity used in making reference materials were: (60)Co≤4.6%, (134)Cs≤4.7%, (137)Cs≤5.0%, total β≤0.6% and (3)H≤1.3%.

  3. A Naturalistic Study of Referred Children and Adolescents with Obsessive-Compulsive Disorder.

    ERIC Educational Resources Information Center

    Masi, Gabriele; Millepiedi, Stefania; Mucci, Maria; Bertini, Nicoletta; Milantoni, Luca; Arcangeli, Francesca

    2005-01-01

    Objective: To report on clinical features, comorbidity, and response to pharmacotherapy in children and adolescents with obsessive-compulsive disorder (OCD) naturalistically followed and treated with serotonin reuptake inhibitors (SRIs). Method: A consecutive series of 94 patients (65 males, 29 females, age 13.6 [+ or -] 2.8 years), referred in…

  4. Validation studies of Karl Fisher reference method for moisture in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With current international standard oven drying (SOD) techniques lacking precision and accuracy statements, a new standard reference method is needed. Volumetric Karl Fischer Titration (KFT) is a widely used measure of moisture content. The method is used in many ASTM methods, 14 NIST SRMs, and te...

  5. Parents and Peers: Serendipity in a Study of Shifting Reference Sources

    ERIC Educational Resources Information Center

    Curtis, Russell L., Jr.

    1974-01-01

    Presents and tests a theory which specifies the conditions under which adolescents shift their valuations between three sets of reference sources--fathers, mothers, and peers; the thesis incorporates components from four interpretations of parent--adolescent cleavage, summarily entitle Push, Pull, Selective Attachment, and Drift. (Author/JM)

  6. A Retrospective Chart Study: The Pathway to a Diagnosis for Adults Referred for ASD Assessment

    ERIC Educational Resources Information Center

    Geurts, Hilde M.; Jansen, Marcel D.

    2012-01-01

    Charts of 125 adults (18 to 82 years), referred to an autism expert team for Autism Spectrum Disorder (ASD) assessment, were reviewed to explore the pathway to an adulthood ASD diagnosis. The participants first contacted the mental health care clinic at a median age of 19 years (range 2 to 78 years). Men contacted the clinic slightly earlier than…

  7. Transition to On-Line Information and Reference Retrieval. Experimental Retrieval Systems Studies, Report Number 4.

    ERIC Educational Resources Information Center

    Smith, William A., Jr.; And Others

    An existing experimental document and reference retrieval system operating in batch processing, tape oriented mode was converted to an on-line mode with user interaction. Objectives were faster response time, integration of functions, and system accessibility at user location. Effects on file organization, addressing techniques, file maintenance,…

  8. Reference design of 100 MW-h lithium/iron sulfide battery system for utility load leveling

    SciTech Connect

    Zivi, S.M.; Kacinskas, H.; Pollack, I.; Chilenskas, A.A.; Barney, D.L.; Grieve, W.; McFarland, B.L.; Sudar, S.; Goldstein, E.; Adler, E.

    1980-03-01

    The first year in a two-year cooperative effort between Argonne National Laboratory and Rockwell International to develop a conceptual design of a lithium alloy/iron sulfide battery for utility load leveling is presented. A conceptual design was developed for a 100 MW-h battery system based upon a parallel-series arrangement of 2.5 kW-h capacity cells. The sales price of such a battery system was estimated to be very high, $80.25/kW-h, exclusive of the cost of the individual cells, the dc-to-ac converters, site preparation, or land acquisition costs. Consequently, the second year's efforts were directed towards developing modified designs with significantly lower potential costs.

  9. Reference genes for quantitative gene expression studies in multiple avian species.

    PubMed

    Olias, Philipp; Adam, Iris; Meyer, Anne; Scharff, Constance; Gruber, Achim D

    2014-01-01

    Quantitative real-time PCR (qPCR) rapidly and reliably quantifies gene expression levels across different experimental conditions. Selection of suitable reference genes is essential for meaningful normalization and thus correct interpretation of data. In recent years, an increasing number of avian species other than the chicken has been investigated molecularly, highlighting the need for an experimentally validated pan-avian primer set for reference genes. Here we report testing a set for 14 candidate reference genes (18S, ABL, GAPDH, GUSB, HMBS, HPRT, PGK1, RPL13, RPL19, RPS7, SDHA, TFRC, VIM, YWHAZ) on different tissues of the mallard (Anas platyrhynchos), domestic chicken (Gallus gallus domesticus), common crane (Grus grus), white-tailed eagle (Haliaeetus albicilla), domestic turkey (Meleagris gallopavo f. domestica), cockatiel (Nymphicus hollandicus), Humboldt penguin (Sphenicus humboldti), ostrich (Struthio camelus) and zebra finch (Taeniopygia guttata), spanning a broad range of the phylogenetic tree of birds. Primer pairs for six to 11 genes were successfully established for each of the nine species. As a proof of principle, we analyzed expression levels of 10 candidate reference genes as well as FOXP2 and the immediate early genes, EGR1 and CFOS, known to be rapidly induced by singing in the avian basal ganglia. We extracted RNA from microbiopsies of the striatal song nucleus Area X of adult male zebra finches after they had sang or remained silent. Using three different statistical algorithms, we identified five genes (18S, PGK1, RPS7, TFRC, YWHAZ) that were stably expressed within each group and also between the singing and silent conditions, establishing them as suitable reference genes. In conclusion, the newly developed pan-avian primer set allows accurate normalization and quantification of gene expression levels in multiple avian species.

  10. 'Aussie normals': an a priori study to develop clinical chemistry reference intervals in a healthy Australian population.

    PubMed

    Koerbin, G; Cavanaugh, J A; Potter, J M; Abhayaratna, W P; West, N P; Glasgow, N; Hawkins, C; Armbruster, D; Oakman, C; Hickman, P E

    2015-02-01

    Development of reference intervals is difficult, time consuming, expensive and beyond the scope of most laboratories. The Aussie Normals study is a direct a priori study to determine reference intervals in healthy Australian adults. All volunteers completed a health and lifestyle questionnaire and exclusion was based on conditions such as pregnancy, diabetes, renal or cardiovascular disease. Up to 91 biochemical analyses were undertaken on a variety of analytical platforms using serum samples collected from 1856 volunteers. We report on our findings for 40 of these analytes and two calculated parameters performed on the Abbott ARCHITECTci8200/ci16200 analysers. Not all samples were analysed for all assays due to volume requirements or assay/instrument availability. Results with elevated interference indices and those deemed unsuitable after clinical evaluation were removed from the database. Reference intervals were partitioned based on the method of Harris and Boyd into three scenarios, combined gender, males and females and age and gender. We have performed a detailed reference interval study on a healthy Australian population considering the effects of sex, age and body mass. These reference intervals may be adapted to other manufacturer's analytical methods using method transference.

  11. Design and pharmacological evaluation of PF-4840154, a non-electrophilic reference agonist of the TrpA1 channel.

    PubMed

    Ryckmans, Thomas; Aubdool, Aisah A; Bodkin, Jennifer V; Cox, Peter; Brain, Susan D; Dupont, Thomas; Fairman, Emma; Hashizume, Yoshinobu; Ishii, Naoko; Kato, Teruhisa; Kitching, Linda; Newman, Julie; Omoto, Kiyoyuki; Rawson, David; Strover, Jade

    2011-08-15

    TrpA1 is an ion channel involved in nociceptive and inflammatory pain. It is implicated in the detection of chemical irritants through covalent binding to a cysteine-rich intracellular region of the protein. While performing an HTS of the Pfizer chemical collection, a class of pyrimidines emerged as a non-reactive, non-covalently binding family of agonists of the rat and human TrpA1 channel. Given the issues identified with the reference agonist Mustard Oil (MO) in screening, a new, non-covalently binding agonist was optimized and proved to be a superior agent to MO for screening purposes. Compound 16a (PF-4840154) is a potent, selective agonist of the rat and human TrpA1 channel and elicited TrpA1-mediated nocifensive behaviour in mouse.

  12. Variability and impact on design of bioequivalence studies.

    PubMed

    Van Peer, Achiel

    2010-03-01

    In 2008, the European Agency for the Evaluation of Medicinal Products released a draft guidance on the investigation of bioequivalence for immediate release dosage forms with systemic action to replace the former guidance of a decade ago. Revisions of the regulatory guidance are based upon many questions over the past years and sometimes continuing scientific discussions on the use of the most suitable statistical analysis methods and study designs, particularly for drugs and drug products with high within-subject variability. Although high within-subject variability is usually associated with a coefficient of variation of 30% or more, new approaches are available in the literature to allow a gradual increase and a levelling off of the bioequivalence limits to some maximum wider values (e.g. 75-133%), dependent on the increase in the within-subject variability. The two-way, cross-over single dose study measuring parent drug is still the design of first choice. A partial replicate design with repeating the reference product and scaling the bioequivalence for the reference variability are proposed for drugs with high within-subject variability. In case of high variability, more regulatory authorities may accept a two-stage or group-sequential bioequivalence design using appropriately adjusted statistical analysis. This review also considers the mechanisms why drugs and drug products may exhibit large variability. The physiological complexity of the gastrointestinal tract and the interaction with the physicochemical properties of drug substances may contribute to the variation in plasma drug concentration-time profiles of drugs and drug products and to variability between and within subjects. A review of submitted bioequivalence studies at the Food and Drug Administration's Office of Generic Drugs over the period 2003-2005 indicated that extensive pre-systemic metabolism of the drug substance was the most important explanation for consistently high variability drugs

  13. Architectural and Functional Design and Evaluation of E-Learning VUIS Based on the Proposed IEEE LTSA Reference Model.

    ERIC Educational Resources Information Center

    O'Droma, Mairtin S.; Ganchev, Ivan; McDonnell, Fergal

    2003-01-01

    Presents a comparative analysis from the Institute of Electrical and Electronics Engineers (IEEE) Learning Technology Standards Committee's (LTSC) of the architectural and functional design of e-learning delivery platforms and applications, e-learning course authoring tools, and learning management systems (LMSs), with a view of assessing how…

  14. Identification and Validation of Reference Genes and Their Impact on Normalized Gene Expression Studies across Cultivated and Wild Cicer Species.

    PubMed

    Reddy, Dumbala Srinivas; Bhatnagar-Mathur, Pooja; Reddy, Palakolanu Sudhakar; Sri Cindhuri, Katamreddy; Sivaji Ganesh, Adusumalli; Sharma, Kiran Kumar

    2016-01-01

    Quantitative Real-Time PCR (qPCR) is a preferred and reliable method for accurate quantification of gene expression to understand precise gene functions. A total of 25 candidate reference genes including traditional and new generation reference genes were selected and evaluated in a diverse set of chickpea samples. The samples used in this study included nine chickpea genotypes (Cicer spp.) comprising of cultivated and wild species, six abiotic stress treatments (drought, salinity, high vapor pressure deficit, abscisic acid, cold and heat shock), and five diverse tissues (leaf, root, flower, seedlings and seed). The geNorm, NormFinder and RefFinder algorithms used to identify stably expressed genes in four sample sets revealed stable expression of UCP and G6PD genes across genotypes, while TIP41 and CAC were highly stable under abiotic stress conditions. While PP2A and ABCT genes were ranked as best for different tissues, ABCT, UCP and CAC were most stable across all samples. This study demonstrated the usefulness of new generation reference genes for more accurate qPCR based gene expression quantification in cultivated as well as wild chickpea species. Validation of the best reference genes was carried out by studying their impact on normalization of aquaporin genes PIP1;4 and TIP3;1, in three contrasting chickpea genotypes under high vapor pressure deficit (VPD) treatment. The chickpea TIP3;1 gene got significantly up regulated under high VPD conditions with higher relative expression in the drought susceptible genotype, confirming the suitability of the selected reference genes for expression analysis. This is the first comprehensive study on the stability of the new generation reference genes for qPCR studies in chickpea across species, different tissues and abiotic stresses.

  15. Identification and Validation of Reference Genes and Their Impact on Normalized Gene Expression Studies across Cultivated and Wild Cicer Species

    PubMed Central

    Reddy, Palakolanu Sudhakar; Sri Cindhuri, Katamreddy; Sivaji Ganesh, Adusumalli; Sharma, Kiran Kumar

    2016-01-01

    Quantitative Real-Time PCR (qPCR) is a preferred and reliable method for accurate quantification of gene expression to understand precise gene functions. A total of 25 candidate reference genes including traditional and new generation reference genes were selected and evaluated in a diverse set of chickpea samples. The samples used in this study included nine chickpea genotypes (Cicer spp.) comprising of cultivated and wild species, six abiotic stress treatments (drought, salinity, high vapor pressure deficit, abscisic acid, cold and heat shock), and five diverse tissues (leaf, root, flower, seedlings and seed). The geNorm, NormFinder and RefFinder algorithms used to identify stably expressed genes in four sample sets revealed stable expression of UCP and G6PD genes across genotypes, while TIP41 and CAC were highly stable under abiotic stress conditions. While PP2A and ABCT genes were ranked as best for different tissues, ABCT, UCP and CAC were most stable across all samples. This study demonstrated the usefulness of new generation reference genes for more accurate qPCR based gene expression quantification in cultivated as well as wild chickpea species. Validation of the best reference genes was carried out by studying their impact on normalization of aquaporin genes PIP1;4 and TIP3;1, in three contrasting chickpea genotypes under high vapor pressure deficit (VPD) treatment. The chickpea TIP3;1 gene got significantly up regulated under high VPD conditions with higher relative expression in the drought susceptible genotype, confirming the suitability of the selected reference genes for expression analysis. This is the first comprehensive study on the stability of the new generation reference genes for qPCR studies in chickpea across species, different tissues and abiotic stresses. PMID:26863232

  16. Advanced heat receiver conceptual design study

    NASA Technical Reports Server (NTRS)

    Kesseli, James; Saunders, Roger; Batchelder, Gary

    1988-01-01

    Solar Dynamic space power systems are candidate electrical power generating systems for future NASA missions. One of the key components of the solar dynamic power system is the solar receiver/thermal energy storage (TES) subsystem. Receiver development was conducted by NASA in the late 1960's and since then a very limited amount of work has been done in this area. Consequently the state of the art (SOA) receivers designed for the IOC space station are large and massive. The objective of the Advanced Heat Receiver Conceptual Design Study is to conceive and analyze advanced high temperature solar dynamic Brayton and Stirling receivers. The goal is to generate innovative receiver concepts that are half of the mass, smaller, and more efficient than the SOA. It is also necessary that these innovative receivers offer ease of manufacturing, less structural complexity and fewer thermal stress problems. Advanced Brayton and Stirling receiver storage units are proposed and analyzed in this study which can potentially meet these goals.

  17. Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team

    NASA Astrophysics Data System (ADS)

    Connolly, John

    1998-01-01

    The Reference Mission was developed over a period of several years and was published in NASA Special Publication 6107 in July 1997. The purpose of the Reference Mission was to provide a workable model for the human exploration of Mars, which is described in enough detail that alternative strategies and implementations can be compared and evaluated. NASA is continuing to develop the Reference Mission and expects to update this report in the near future. It was the purpose of the Reference Mission to develop scenarios based on the needs of scientists and explorers who want to conduct research on Mars; however, more work on the surface-mission aspects of the Reference Mission is required and is getting under way. Some aspects of the Reference Mission that are important for the consideration of the surface mission definition include: (1) a split mission strategy, which arrives at the surface two years before the arrival of the first crew; (2) three missions to the outpost site over a 6-year period; (3) a plant capable of producing rocket propellant for lifting off Mars and caches of water, O, and inert gases for the life-support system; (4) a hybrid physico-chemical/bioregenerative life-support system, which emphasizes the bioregenerative system more in later parts of the scenario; (5) a nuclear reactor power supply, which provides enough power for all operations, including the operation of a bioregenerative life-support system as well as the propellant and consumable plant; (6) capability for at least two people to be outside the habitat each day of the surface stay; (7) telerobotic and human-operated transportation vehicles, including a pressurized rover capable of supporting trips of several days' duration from the habitat; (7) crew stay times of 500 days on the surface, with six-person crews; and (8) multiple functional redundancies to reduce risks to the crews on the surface. New concepts are being sought that would reduce the overall cost for this exploration

  18. Longitudinal studies of cardiac troponin-I concentrations in serum from male Sprague Dawley rats: baseline reference ranges and effects of handling and placebo dosing on biological variability.

    PubMed

    Schultze, A Eric; Carpenter, Kent H; Wians, Frank H; Agee, Sara J; Minyard, Jennifer; Lu, Quynh Anh; Todd, John; Konrad, Robert J

    2009-10-01

    Serum cardiac troponin-I has been validated as a biomarker for cardiotoxicity in numerous animal models; however, baseline reference ranges for cTnI concentration in a healthy population of laboratory rats, as well as an investigation of biological cTnI variability in rats with respect to time, handling, and placebo dosing methods, have not been reported. In this study, we used an ultrasensitive cTnI immunoassay to quantify hourly concentrations of cTnI in live rats handled under standard laboratory conditions using 15 microL of serum per determination. The baseline reference range (mean 4.94 pg/mL, range 1-15 pg/mL, 99% confidence interval [CI]) of cTnI concentration in rats was consistent with previously reported reference ranges for cTnI in humans (1-12 pg/mL) and with preliminary studies in dogs (1-4 pg/mL) and monkeys (4-5 pg/mL) using the same cTnI assay method. In addition, cTnI concentrations in individual rat serum samples show minimal biological variability over a twenty-four-hour interval when compared to a meaningful reference change value of 193% to 206%. Furthermore, measurements of cTnI concentration were consistent within the reference limits in individual rats over long periods and under three different standard laboratory handling conditions. Thus, using this new method, rats can be followed longitudinally at hourly intervals, and a doubling of cTnI concentration would be significant above biological variability. This is a new paradigm for preclinical testing, which allows transient changes in cTnI concentration to be accurately quantified. This understanding of baseline and biological variability in rats will be fundamental for designing and analyzing future studies that assess potential cardiotoxicity in drug development.

  19. A randomized, crossover pharmacokinetic study comparing generic tacrolimus vs. the reference formulation in subpopulations of kidney transplant patients.

    PubMed

    Bloom, R D; Trofe-Clark, J; Wiland, A; Alloway, R R

    2013-01-01

    An exploratory, post hoc analysis was performed using data from a prospective, multicenter, open-label, randomized, two-period (14 d per period), two-sequence, crossover, steady-state pharmacokinetic study comparing generic tacrolimus (Sandoz) vs. reference tacrolimus in stable renal transplant patients receiving their pre-study twice-daily dose. Pharmacokinetic parameters were compared in 68 patients according to gender, African American ethnicity, the presence or absence of diabetes, and use of steroids. The ratios of tacrolimus AUC0-12 h , Cmax , and C12 with generic vs. reference tacrolimus were calculated using the geometric mean (GM) of dose-normalized values at days 14 and 28. Mean (SD) tacrolimus dose at baseline was 5.7 (4.2) mg/d. There were no consistent differences in dose-normalized AUC0-12 h , C12 , Cmax, or tmax between the generic and reference preparations within subpopulations. The 90% confidence intervals (CI) for the ratios of dose-normalized AUC0-12 h and C12 with generic vs. reference tacrolimus were within 80-125% for all subpopulations, as were 90% CIs for Cmax other than for females, African Americans, and non-diabetics, which is not unexpected given the wide variability of tacrolimus Cmax and the small subpopulation sizes. These exploratory results suggest that this generic tacrolimus preparation would be expected to offer comparable bioavailability to the reference drug in these patient subpopulations.

  20. Compositional Analysis of Biomass Reference Materials: Results from an Interlaboratory Study

    PubMed Central

    Wolfrum, Edward J.; Yen, James H.; Sharpless, Katherine E.

    2016-01-01

    Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached and an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. The major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original

  1. Compositional analysis of biomass reference materials: Results from an interlaboratory study

    SciTech Connect

    Templeton, David W.; Wolfrum, Edward J.; Yen, James H.; Sharpless, Katherine E.

    2015-10-29

    Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached and an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. Here, the major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original

  2. Compositional analysis of biomass reference materials: Results from an interlaboratory study

    DOE PAGES

    Templeton, David W.; Wolfrum, Edward J.; Yen, James H.; ...

    2015-10-29

    Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached andmore » an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. Here, the major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original

  3. Genetic Epidemiology of COPD (COPDGene) Study Design

    PubMed Central

    Regan, Elizabeth A.; Hokanson, John E.; Murphy, James R.; Make, Barry; Lynch, David A.; Beaty, Terri H.; Curran-Everett, Douglas; Silverman, Edwin K.; Crapo, James D.

    2010-01-01

    Background COPDGeneis a multicenter observational study designed to identify genetic factors associated with COPD. It will also characterize chest CT phenotypes in COPD subjects, including assessment of emphysema, gas trapping, and airway wall thickening. Finally, subtypes of COPD based on these phenotypes will be used in a comprehensive genome-wide study to identify COPD susceptibility genes. Methods/Results COPDGene will enroll 10,000 smokers with and without COPD across the GOLD stages. Both Non-Hispanic white and African-American subjects are included in the cohort. Inspiratory and expiratory chest CT scans will be obtained on all participants. In addition to the cross-sectional enrollment process, these subjects will be followed regularly for longitudinal studies. A genome-wide association study (GWAS) will be done on an initial group of 4000 subjects to identify genetic variants associated with case-control status and several quantitative phenotypes related to COPD. The initial findings will be verified in an additional 2000 COPD cases and 2000 smoking control subjects, and further validation association studies will be carried out. Conclusions COPDGene will provide important new information about genetic factors in COPD, and will characterize the disease process using high resolution CT scans. Understanding genetic factors and CT phenotypes that define COPD will potentially permit earlier diagnosis of this disease and may lead to the development of treatments to modify progression. PMID:20214461

  4. User’s Reference Manual: Computer Program for Design and Analysis of Inverted-T Retaining Walls and Floodwalls (TWDA).

    DTIC Science & Technology

    1980-12-01

    methodology. The analysis procedure considers overturn- ing, sliding, and bearing pressure, relative to the soil immediately adjacent to the wall...equilibrium methods. (e) Limiting value of the overturning stalbi lity resultant ratio . (f) Reinforced concrete design parameters. (g) Specification...combination of Values inside user-defined ranges of base width, bottom of tow elevation, base slope, and key length, for a given stem ratio or toe width

  5. Ponnequin Wind Energy Project: Reference site avian study, January 1, 1998--December 31, 1998

    SciTech Connect

    Kerlinger, P.; Curry, R.; Ryder, R.

    2000-04-05

    This report summarizes the results of surveys completed during the period January 1, 1998, through December 31, 1998, at the Ponnequin Wind Energy Project in Weld County, Colorado. The surveys were conducted at two reference sites, and include a pre-construction avian abundance and use survey and raptor nesting, prey, and carcass surveys. The reference sites were situated immediately to the west of the project site in Weld County, Colorado, and 4.8 kilometers to the north of the site in Laramie County, Wyoming. The surveys were conducted along two 800-meter (m) main transects at each site with two 400-m (by 100-m) perpendicular transects. About 30 complete surveys were completed during the year, with a greater frequency of surveys in the late spring and early autumn. The surveys revealed mostly common species, with no endangered or threatened species on the sites. Small numbers of raptors were observed on or near the project and reference areas. During the winter, avian use and abundance was minimal. Prey species consisted primarily of thirteen-lined ground squirrels and northern pocket gophers. Two songbird carcasses were found. The results of these surveys, combined with data from several more months of surveys, will be compared to surveys conducted after construction of the wind farm.

  6. Ultrasound assessment of medial meniscal extrusion: a validation study using MRI as reference standard.

    PubMed

    Nogueira-Barbosa, Marcello H; Gregio-Junior, Everaldo; Lorenzato, Mario M; Guermazi, Ali; Roemer, Frank W; Chagas-Neto, Francisco A; Crema, Michel D

    2015-03-01

    OBJECTIVE. The purpose of this article is to validate both semiquantitative and quantitative ultrasound assessment of medial meniscal extrusion using MRI assessment as the reference standard. SUBJECTS AND METHODS. Ninety-three consecutive patients with chronic knee pain referred for knee MRI were evaluated by ultrasound and MRI on the same day. Two musculoskeletal radiologists assessed meniscal extrusion on ultrasound and MRI separately and independently and graded it semiquantitatively as follows: 0 (< 2 mm), 1 (≥ 2 mm and < 4 mm), and 2 (≥ 4 mm). Agreement between the ultrasound and MRI evaluations was determined using weighted kappa statistics. Intraclass correlation coefficients were used to evaluate agreement using the absolute values of extrusion (quantitative assessment). We further evaluated the diagnostic performance of ultrasound for the detection of medial meniscal extrusion using MRI as the reference standard. RESULTS. For semiquantitative grading, agreement between ultrasound and MRI was moderate for reader 1 (κ = 0.57) and substantial for reader 2 (κ = 0.64). Substantial agreement was found for both readers (intraclass correlation coefficients, 0.73 and 0.70) when comparing quantitative assessment of meniscal extrusion between ultrasound and MRI. Ultrasound showed excellent sensitivity (95% and 96% for each reader) and good specificity (82% and 70% for each reader) in the detection of meniscal extrusion. CONCLUSION. Ultrasound assessment of meniscal extrusion is reliable and can be used for both quantitative and semiquantitative assessment, exhibiting excellent diagnostic performance for the detection of meniscal extrusion compared with MRI.

  7. Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process

    NASA Technical Reports Server (NTRS)

    Gillette, W. B.; Turner, M. J.; Southall, J. W.; Whitener, P. C.; Kowalik, J. S.

    1973-01-01

    The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system.

  8. Conceptual designs for waste packages for horizontal or vertical emplacement in a repository in salt for reference in the site characterization plan

    SciTech Connect

    Not Available

    1987-06-01

    This report includes the options of horizontal and vertical emplacement, the addition of a phased repository, an additional waste form (intact spent fuel), revised geotechnical data appropriate for the Deaf Smith County site, new corrosion data for the container, and new repository design data. The waste package consists of waste form and canister within a thick-walled, low-carbon steel container surrounded by packing. The container is a hollow cylinder with a flat head welded to each end. The design concepts for the waste container or vertical and horizontal emplacement are identical. This report discusses the results of analyses of aspects of the reference waste package concept needing changes because of new data and information believed applicable to the Deaf Smith County site. Included are waste package conceptual designs or (1) the reference defense high-level waste form from the Savannah River Plant; (2) intact spent fuel with our pressurized-water-reactor or nine boiling-water-reactor assemblies per package for emplacement during Phase 1 of repository operation; and (3) spent fuel which has been disassembled and consolidated into a segmented cylindrical canister with rods from either 12 pressurized-water-reactor or 30 boiling-water-reactor assemblies per package for emplacement during Phase 2. 30 refs., 61 figs., 30 tabs.

  9. Inertial Motion Capture Costume Design Study.

    PubMed

    Szczęsna, Agnieszka; Skurowski, Przemysław; Lach, Ewa; Pruszowski, Przemysław; Pęszor, Damian; Paszkuta, Marcin; Słupik, Janusz; Lebek, Kamil; Janiak, Mateusz; Polański, Andrzej; Wojciechowski, Konrad

    2017-03-17

    The paper describes a scalable, wearable multi-sensor system for motion capture based on inertial measurement units (IMUs). Such a unit is composed of accelerometer, gyroscope and magnetometer. The final quality of an obtained motion arises from all the individual parts of the described system. The proposed system is a sequence of the following stages: sensor data acquisition, sensor orientation estimation, system calibration, pose estimation and data visualisation. The construction of the system's architecture with the dataflow programming paradigm makes it easy to add, remove and replace the data processing steps. The modular architecture of the system allows an effortless introduction of a new sensor orientation estimation algorithms. The original contribution of the paper is the design study of the individual components used in the motion capture system. The two key steps of the system design are explored in this paper: the evaluation of sensors and algorithms for the orientation estimation. The three chosen algorithms have been implemented and investigated as part of the experiment. Due to the fact that the selection of the sensor has a significant impact on the final result, the sensor evaluation process is also explained and tested. The experimental results confirmed that the choice of sensor and orientation estimation algorithm affect the quality of the final results.

  10. Advanced EVA system design requirements study

    NASA Technical Reports Server (NTRS)

    Woods, T. G.

    1988-01-01

    The results are presented of a study to identify specific criteria regarding space station extravehicular activity system (EVAS) hardware requirements. Key EVA design issues include maintainability, technology readiness, LSS volume vs. EVA time available, suit pressure/cabin pressure relationship and productivity effects, crew autonomy, integration of EVA as a program resource, and standardization of task interfaces. A variety of DOD EVA systems issues were taken into consideration. Recommendations include: (1) crew limitations, not hardware limitations; (2) capability to perform all of 15 generic missions; (3) 90 days on-orbit maintainability with 50 percent duty cycle as minimum; and (4) use by payload sponsors of JSC document 10615A plus a Generic Tool Kit and Specialized Tool Kit description. EVA baseline design requirements and criteria, including requirements of various subsystems, are outlined. Space station/EVA system interface requirements and EVA accommodations are discussed in the areas of atmosphere composition and pressure, communications, data management, logistics, safe haven, SS exterior and interior requirements, and SS airlock.

  11. Inertial Motion Capture Costume Design Study

    PubMed Central

    Szczęsna, Agnieszka; Skurowski, Przemysław; Lach, Ewa; Pruszowski, Przemysław; Pęszor, Damian; Paszkuta, Marcin; Słupik, Janusz; Lebek, Kamil; Janiak, Mateusz; Polański, Andrzej; Wojciechowski, Konrad

    2017-01-01

    The paper describes a scalable, wearable multi-sensor system for motion capture based on inertial measurement units (IMUs). Such a unit is composed of accelerometer, gyroscope and magnetometer. The final quality of an obtained motion arises from all the individual parts of the described system. The proposed system is a sequence of the following stages: sensor data acquisition, sensor orientation estimation, system calibration, pose estimation and data visualisation. The construction of the system’s architecture with the dataflow programming paradigm makes it easy to add, remove and replace the data processing steps. The modular architecture of the system allows an effortless introduction of a new sensor orientation estimation algorithms. The original contribution of the paper is the design study of the individual components used in the motion capture system. The two key steps of the system design are explored in this paper: the evaluation of sensors and algorithms for the orientation estimation. The three chosen algorithms have been implemented and investigated as part of the experiment. Due to the fact that the selection of the sensor has a significant impact on the final result, the sensor evaluation process is also explained and tested. The experimental results confirmed that the choice of sensor and orientation estimation algorithm affect the quality of the final results. PMID:28304337

  12. Selection of endogenous reference microRNA genes for quantitative reverse transcription polymerase chain reaction studies of boar spermatozoa cryopreservation.

    PubMed

    Zhang, Yan; Zeng, Chang-Jun; He, Lian; Ding, Li; Tang, Ke-Yi; Peng, Wen-Pei

    2015-03-01

    It is important to select high-quality reference genes for the accurate interpretation of quantitative reverse transcription polymerase chain reaction data, in particular for certain miRNAs that may demonstrate unstable expression. Although several studies have attempted to validate reference miRNA genes in the porcine testis, spermatozoa, and other tissues, no validation studies have been carried out on cryopreserved boar spermatozoa. In this study, 15 commonly used reference miRNA genes (5S, let-7c-5p, ssc-miR-16-5p, ssc-miR-17-5p, ssc-miR-20a, ssc-miR-23a, ssc-miR-24-3p, ssc-miR-26a, ssc-miR-27a-3p, ssc-miR-92a, ssc-miR-103-3p, ssc-miR-106a, ssc-miR-107-3p, ssc-miR-186, and ssc-miR-221-3p) were selected to evaluate the expression stability of target miRNAs in boar spermatozoa under different experimental conditions and concentrations. The stability of the expression of these reference miRNAs across each sample was evaluated using geNorm, NormFinder, and BestKeeper software. The results showed that ssc-miR-186 (mean rank value = 5.00), ssc-miR-23a (5.33), and ssc-miR-27a (5.33) were the most suitable reference genes using three different statistical algorithms and comprehensive ranking. The identification of these reference miRNAs will allow for more accurate quantification of the changes in miRNA expression during cryopreservation of boar spermatozoa.

  13. China Connections Reference Book.

    ERIC Educational Resources Information Center

    Kalat, Marie B.; Hoermann, Elizabeth F.

    This reference book focuses on six aspects of the geography of the People's Republic of China. They are: territory, governing units, population and land use, waterways, land forms, and climates. Designed as a primary reference, the book explains how the Chinese people and their lifestyles are affected by China's geography. Special components…

  14. Selection of reference genes for gene expression studies in virus-infected monocots using quantitative real-time PCR.

    PubMed

    Zhang, Kun; Niu, Shaofang; Di, Dianping; Shi, Lindan; Liu, Deshui; Cao, Xiuling; Miao, Hongqin; Wang, Xianbing; Han, Chenggui; Yu, Jialin; Li, Dawei; Zhang, Yongliang

    2013-10-10

    Both genome-wide transcriptomic surveys of the mRNA expression profiles and virus-induced gene silencing-based molecular studies of target gene during virus-plant interaction involve the precise estimation of the transcript abundance. Quantitative real-time PCR (qPCR) is the most widely adopted technique for mRNA quantification. In order to obtain reliable quantification of transcripts, identification of the best reference genes forms the basis of the preliminary work. Nevertheless, the stability of internal controls in virus-infected monocots needs to be fully explored. In this work, the suitability of ten housekeeping genes (ACT, EF1α, FBOX, GAPDH, GTPB, PP2A, SAND, TUBβ, UBC18 and UK) for potential use as reference genes in qPCR were investigated in five different monocot plants (Brachypodium, barley, sorghum, wheat and maize) under infection with different viruses including Barley stripe mosaic virus (BSMV), Brome mosaic virus (BMV), Rice black-streaked dwarf virus (RBSDV) and Sugarcane mosaic virus (SCMV). By using three different algorithms, the most appropriate reference genes or their combinations were identified for different experimental sets and their effectiveness for the normalisation of expression studies were further validated by quantitative analysis of a well-studied PR-1 gene. These results facilitate the selection of desirable reference genes for more accurate gene expression studies in virus-infected monocots.

  15. Identification of reliable reference genes for qRT-PCR studies of the developing mouse mammary gland

    PubMed Central

    van de Moosdijk, Anoeska Agatha Alida; van Amerongen, Renée

    2016-01-01

    Cell growth and differentiation are often driven by subtle changes in gene expression. Many challenges still exist in detecting these changes, particularly in the context of a complex, developing tissue. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) allows relatively high-throughput evaluation of multiple genes and developmental time points. Proper quantification of gene expression levels by qRT-PCR requires normalization to one or more reference genes. Traditionally, these genes have been selected based on their presumed “housekeeping” function, with the implicit assumption that they are stably expressed over the entire experimental set. However, this is rarely tested empirically. Here we describe the identification of novel reference genes for the mouse mammary gland based on their stable expression in published microarray datasets. We compared eight novel candidate reference genes (Arpc3, Clock, Ctbp1, Phf7, Prdx1, Sugp2, Taf11 and Usp7) to eight traditional ones (18S, Actb, Gapdh, Hmbs, Hprt, Rpl13a, Sdha and Tbp) and analysed all genes for stable expression in the mouse mammary gland from pre-puberty to adulthood using four different algorithms (GeNorm, DeltaCt, BestKeeper and NormFinder). Prdx1, Phf7 and Ctbp1 were validated as novel and reliable, tissue-specific reference genes that outperform traditional reference genes in qRT-PCR studies of postnatal mammary gland development. PMID:27752147

  16. Reference genes for quantitative real-time polymerase chain reaction studies in soybean plants under hypoxic conditions.

    PubMed

    Nakayama, T J; Rodrigues, F A; Neumaier, N; Marcelino-Guimarães, F C; Farias, J R B; de Oliveira, M C N; Borém, A; de Oliveira, A C B; Emygdio, B M; Nepomuceno, A L

    2014-02-13

    Quantitative real-time polymerase chain reaction (RT-qPCR) is a powerful tool used to measure gene expression. However, because of its high sensitivity, the method is strongly influenced by the quality and concentration of the template cDNA and by the amplification efficiency. Relative quantification is an effective strategy for correcting random and systematic errors by using the expression level of reference gene(s) to normalize the expression level of the genes of interest. To identify soybean reference genes for use in studies of flooding stress, we compared 5 candidate reference genes (CRGs) with the NormFinder and GeNorm programs to select the best internal control. The expression stability of the CRGs was evaluated in root tissues from soybean plants subjected to hypoxic conditions. Elongation factor 1-beta and actin-11 were identified as the most appropriate genes for RT-qPCR normalization by both the NormFinder and GeNorm analyses. The expression profiles of the genes for alcohol dehydrogenase 1, sucrose synthase 4, and ascorbate peroxidase 2 were analyzed by comparing different normalizing combinations (including no normalization) of the selected reference genes. Here, we have identified potential genes for use as references for RT-qPCR normalization in experiments with soybean roots growing in O2-depleted environments, such as flooding-stressed plants.

  17. Collaborative study for the calibration of HCV RNA, HBV DNA and HIV RNA reference preparations against the relative international standards.

    PubMed

    Pisani, Giulio; Marino, Francesco; Cristiano, Karen; Bisso, Guillermo Mario; Mele, Caludio; Luciani, Francesca; Wirz, Maria; Gentili, Giuliano

    2007-01-01

    We organised a collaborative study to calibrate three new ISS reference preparations (ISS: Istituto Superiore di Sanità), one for HCV RNA, one for HIV RNA and one for HBV DNA, to be used for nucleic acid amplification techniques (NAT) in blood testing. Serial dilution of the ISS reference preparations and the respective international standards were tested in different days by each participating laboratory using two commercial NAT assays. Data were collected by the ISS for statistical analysis. Based on the mean potency of the HCV RNA and HIV RNA preparations, calculated from the results provided by the 12 participating laboratories, a definitive concentrations of 5700 IU/mL and 4000 IU/mL, respectively, were assigned to the reference materials. On the contrary, it was not possible to obtain a consensus titre for the HBV DNA reference material. These new Italian reference preparations (HCV RNA ISS/1005 and HIV RNA ISS/1005) calibrated against the respective international standards are available free of charge to any laboratory upon request.

  18. Design study of prestressed rotor spar concept

    NASA Technical Reports Server (NTRS)

    Gleich, D.

    1980-01-01

    Studies on the Bell Helicopter 540 Rotor System of the AH-1G helicopter were performed. The stiffness, mass and geometric configurations of the Bell blade were matched to give a dynamically similar prestressed composite blade. A multi-tube, prestressed composite spar blade configuration was designed for superior ballistic survivability at low life cycle cost. The composite spar prestresses, imparted during fabrication, are chosen to maintain compression in the high strength cryogenically stretchformed 304-L stainless steel liner and tension in the overwrapped HTS graphite fibers under operating loads. This prestressing results in greatly improved crack propagation and fatigue resistance as well as enhanced fiber stiffness properties. Advantages projected for the prestressed composite rotor spar concept include increased operational life and improved ballistic survivability at low life cycle cost.

  19. Preliminary systems design study assessment report

    SciTech Connect

    Mayberry, J.L.; Feizollahi, F.; Del Signore, J.C.

    1991-10-01

    The System Design Study (SDS), part of the Waste Technology Development Department of the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. The SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept. The SDS results are published in eight volumes. Volume I contains an executive summary. The SDS summary and analysis of results are presented in Volume II. Volumes III through VII contain descriptions of twelve system and four subsystem concepts. Volume VIII contains the appendixes.

  20. Preliminary Systems Design Study assessment report

    SciTech Connect

    Mayberry, J.L.; Quapp, W.J.; Feizollahi, F.; Del Signore, J.C.

    1991-07-01

    The System Design Study (SDS), part of the Waste Technology Development Department at the Idaho National Engineering Laboratory (INEL), examined techniques available for the remediation of hazardous and transuranic waste stored at the Radioactive Waste Management Complex's Subsurface Disposal Area at the INEL. Using specific technologies, system concepts for treating the buried waste and the surrounding contaminated soil were evaluated. Evaluation included implementability, effectiveness, and cost. SDS resulted in the development of technology requirements including demonstration, testing, and evaluation activities needed for implementing each concept. The SDS results are published in eight volumes. Volume 1 contains an executive summary. The SDS summary and analysis of results are presented in Volume 2. Volumes 3 through 7 contain detailed descriptions of twelve system and four subsystem concepts. Volume 8 contains the appendixes. 23 refs., 23 figs., 16 tabs.

  1. The microwave radiometer spacecraft: A design study

    NASA Technical Reports Server (NTRS)

    Wright, R. L. (Editor)

    1981-01-01

    A large passive microwave radiometer spacecraft with near all weather capability of monitoring soil moisture for global crop forecasting was designed. The design, emphasizing large space structures technology, characterized the mission hardware at the conceptual level in sufficient detail to identify enabling and pacing technologies. Mission and spacecraft requirements, design and structural concepts, electromagnetic concepts, and control concepts are addressed.

  2. Background radiation, electrical work, and some other exposures associated with acute myeloid leukemia in a case-referent study.

    PubMed

    Flodin, U; Fredriksson, M; Persson, B; Hardell, L; Axelson, O

    1986-01-01

    The effect of potential risk factors for acute myeloid leukemia was evaluated in a case-referent study encompassing 59 cases and 354 referents, all of whom were alive. Information on exposure was obtained through a questionnaire mailed to the subjects. The possible effect of background radiation was evaluated by means of a gamma radiation index, which accounted for the differences between cases and referents in this respect, i.e., in time spent in concrete buildings both at home and at work places. In the 20-54 yr old age group, there was an association between leukemia morbidity and index of background radiation. X-ray treatment and electrical work were also associated with increased rate ratios. With regard to solvents, only styrene appeared as a risk factor, but the number of exposed subjects was small. Other exposures were less clearly associated with increased risks.

  3. Made to Measure: Designs Tailored to Your Study Needs.

    PubMed

    Jupiter, Daniel C

    2015-01-01

    What is the best study design? Why would we prefer one to another? With many different designs, what should we be looking for in our critical reading of the literature? We discuss a variety of designs, and their appropriate use.

  4. A comparison of three infant skinfold reference standards: Tanner-Whitehouse, Cambridge Infant Growth Study, and WHO Child Growth Standards.

    PubMed

    Miller, Elizabeth M

    2015-10-01

    As researchers increasingly focus on early infancy as a critical period of development, there is a greater need for methodological tools that can address all aspects of infant growth. Infant skinfold measures, in particular, are measurements in need of reliable reference standards that encompass all ages of infants and provide an accurate assessment of the relative fatness of a population. This report evaluates three published reference standards for infant skinfold measurements: Tanner-Whitehouse, Cambridge Infant Growth Study, and the World Health Organization (WHO) Child Growth Standards. To assess these standards, triceps skinfolds from a population of rural Kenyan infants (n = 250) and triceps skinfolds and subscapular skinfolds from infants in the National Health and Nutrition Examination Survey 1999-2002 (NHANES; n = 1197) were calculated as z-scores from the lambda-mu-sigma curves provided by each reference population. The Tanner-Whitehouse standards represented both the Kenyan and US populations as lean, while the Cambridge standards represented both populations as overfat. The distribution of z-scores based on the WHO standards fell in the middle, but excluded infants from both populations who were below the age of 3 months. Based on these results, the WHO reference standard is the best skinfold reference standard for infants over the age of 3 months. For populations with infants of all ages, the Tanner-Whitehouse standards are recommended, despite representing both study populations as underfat. Ideally, the WHO will extend their reference standard to include infants between the ages of 0 and 3 months.

  5. Chicago Healthy Aging Study: Objectives and Design

    PubMed Central

    Pirzada, Amber; Reid, Kathryn; Kim, Daniel; Garside, Daniel B.; Lu, Brandon; Vu, Thanh-Huyen T.; Lloyd-Jones, Donald M.; Zee, Phyllis; Liu, Kiang; Stamler, Jeremiah; Daviglus, Martha L.

    2013-01-01

    Investigators in the Chicago Healthy Aging Study (CHAS) reexamined 1,395 surviving participants aged 65–84 years (28% women) from the Chicago Heart Association Detection Project in Industry (CHA) 1967–1973 cohort whose cardiovascular disease (CVD) risk profiles were originally ascertained at ages 25–44 years. CHAS investigators reexamined 421 participants who were low-risk (LR) at baseline and 974 participants who were non-LR at baseline. LR was defined as having favorable levels of 4 major CVD risk factors: serum total cholesterol level <200 mg/dL and no use of cholesterol-lowering medication; blood pressure 120/≤80 mm Hg and no use of antihypertensive medication; no current smoking; and no history of diabetes or heart attack. While the potential of LR status in overcoming the CVD epidemic is being recognized, the long-term association of LR with objectively measured health in older age has not been examined. It is hypothesized that persons who were LR in 1967–1973 and have survived to older age will have less clinical and subclinical CVD, lower levels of inflammatory markers, and better physical performance/functioning and sleep quality. Here we describe the rationale, objectives, design, and implementation of this longitudinal epidemiologic study, compare baseline and follow-up characteristics of participants and nonparticipants, and highlight the feasibility of reexamining study participants after an extended period postbaseline with minimal interim contact. PMID:23669655

  6. Reference intervals of bone turnover markers in healthy premenopausal women: results from a cross-sectional European study.

    PubMed

    Eastell, Richard; Garnero, Patrick; Audebert, Christine; Cahall, David L

    2012-05-01

    Robust validated reference intervals for bone turnover markers (BTMs) are required to assess fracture risk and effectiveness of therapy. However, there are currently limited reference intervals for BTMs in premenopausal women, especially comparing manual and automated assays. This study determined the BTM reference intervals using automated and manual assays, compared the results obtained from two different assays, and evaluated the factors that may affect BTM levels. This was a cross-sectional registry study in 194 healthy, premenopausal, European Caucasian women aged 35 to 39years from France (n=98) and Denmark (n=96). Two independent specialized laboratories, one in France (Synarc) and the other in Denmark (Nordic Bioscience), analyzed blood and urine samples from each woman for BTM levels. The type of assay used in this study significantly affected the reference intervals obtained for serum cross-linked C-terminal telopeptide of type I collagen (sCTX) and urinary cross-linked N-terminal telopeptides of type I collagen (uNTX/Cr; both P<0.001), but not for serum procollagen type I amino-terminal propeptide (PINP; P=0.28). The Serum Crosslaps® ELISA; Microtitre-plate based ELISA; Metra BAP EIA; and UniQ® PINP RIA assays yielded higher BTM reference values. The reference intervals for the BTMs, as measured with Serum β-Crosslaps, Elecsys® 2010 Systems; VITROS® ECI System; Ostase®, Access® Immunoassay System; and Total PINP, Elecsys® 2010 Systems assays, were 0.111-0.791ng/mL for sCTX, 12.3-59.7nmol BCE/mmol creatinine for uNTX/Cr, 5.8-17.5ng/mL for bone alkaline phosphatase (ALP), and 17.3-83.4ng/mL for PINP, respectively. When measured with Serum Crosslaps® ELISA, Microtitre-plate based ELISA, Metra BAP EIA, and UniQ® PINP RIA, the reference intervals were 0.177-0.862ng/mL for sCTX, 22.6-95.7nmol BCE/mmol creatinine for uNTX/Cr, 14.8-38.8U/L for bone ALP, and 19.5-75.2ng/mL for PINP, respectively. The clinical interpretation of the BTMs of a subject

  7. Reference Services.

    ERIC Educational Resources Information Center

    Bunge, Charles A.

    1999-01-01

    Discusses library reference services. Topics include the historical development of reference services; instruction in library use, particularly in college and university libraries; guidance; information and referral services and how they differ from traditional question-answering service; and future concerns, including user fees and the planning…

  8. Reference Revolutions.

    ERIC Educational Resources Information Center

    Mason, Marilyn Gell

    1998-01-01

    Describes developments in Online Computer Library Center (OCLC) electronic reference services. Presents a background on networked cataloging and the initial implementation of reference services by OCLC. Discusses the introduction of OCLC FirstSearch service, which today offers access to over 65 databases, future developments in integrated…

  9. Unstable Expression of Commonly Used Reference Genes in Rat Pancreatic Islets Early after Isolation Affects Results of Gene Expression Studies.

    PubMed

    Kosinová, Lucie; Cahová, Monika; Fábryová, Eva; Týcová, Irena; Koblas, Tomáš; Leontovyč, Ivan; Saudek, František; Kříž, Jan

    2016-01-01

    The use of RT-qPCR provides a powerful tool for gene expression studies; however, the proper interpretation of the obtained data is crucially dependent on accurate normalization based on stable reference genes. Recently, strong evidence has been shown indicating that the expression of many commonly used reference genes may vary significantly due to diverse experimental conditions. The isolation of pancreatic islets is a complicated procedure which creates severe mechanical and metabolic stress leading possibly to cellular damage and alteration of gene expression. Despite of this, freshly isolated islets frequently serve as a control in various gene expression and intervention studies. The aim of our study was to determine expression of 16 candidate reference genes and one gene of interest (F3) in isolated rat pancreatic islets during short-term cultivation in order to find a suitable endogenous control for gene expression studies. We compared the expression stability of the most commonly used reference genes and evaluated the reliability of relative and absolute quantification using RT-qPCR during 0-120 hrs after isolation. In freshly isolated islets, the expression of all tested genes was markedly depressed and it increased several times throughout the first 48 hrs of cultivation. We observed significant variability among samples at 0 and 24 hrs but substantial stabilization from 48 hrs onwards. During the first 48 hrs, relative quantification failed to reflect the real changes in respective mRNA concentrations while in the interval 48-120 hrs, the relative expression generally paralleled the results determined by absolute quantification. Thus, our data call into question the suitability of relative quantification for gene expression analysis in pancreatic islets during the first 48 hrs of cultivation, as the results may be significantly affected by unstable expression of reference genes. However, this method could provide reliable information from 48 hrs onwards.

  10. HEALTHY study rationale, design and methods

    PubMed Central

    2009-01-01

    The HEALTHY primary prevention trial was designed and implemented in response to the growing numbers of children and adolescents being diagnosed with type 2 diabetes. The objective was to moderate risk factors for type 2 diabetes. Modifiable risk factors measured were indicators of adiposity and glycemic dysregulation: body mass index ≥85th percentile, fasting glucose ≥5.55 mmol l-1 (100 mg per 100 ml) and fasting insulin ≥180 pmol l-1 (30 μU ml-1). A series of pilot studies established the feasibility of performing data collection procedures and tested the development of an intervention consisting of four integrated components: (1) changes in the quantity and nutritional quality of food and beverage offerings throughout the total school food environment; (2) physical education class lesson plans and accompanying equipment to increase both participation and number of minutes spent in moderate-to-vigorous physical activity; (3) brief classroom activities and family outreach vehicles to increase knowledge, enhance decision-making skills and support and reinforce youth in accomplishing goals; and (4) communications and social marketing strategies to enhance and promote changes through messages, images, events and activities. Expert study staff provided training, assistance, materials and guidance for school faculty and staff to implement the intervention components. A cohort of students were enrolled in sixth grade and followed to end of eighth grade. They attended a health screening data collection at baseline and end of study that involved measurement of height, weight, blood pressure, waist circumference and a fasting blood draw. Height and weight were also collected at the end of the seventh grade. The study was conducted in 42 middle schools, six at each of seven locations across the country, with 21 schools randomized to receive the intervention and 21 to act as controls (data collection activities only). Middle school was the unit of sample size and

  11. Improving study design for antidepressant effectiveness assessment.

    PubMed

    Naudet, Florian; Millet, Bruno; Reymann, Jean Michel; Falissard, Bruno

    2013-09-01

    Antidepressants effectiveness in major depressive disorder (MDD) is still questioned because the extrapolation of randomized controlled trial (RCT) results to "real life" settings is problematic. The application of the RCT paradigm in a disorder of this type, where global care plays a central role, raises questions regarding the internal and external validity of this type of study. Outcome measurement, attrition rates, the ability of the double-blind design to control for expectations, placebo response, the representativeness of trial participants and publication bias are major methodological pitfalls. This review discusses these issues. It is illustrated using original data and proposes some alternatives for assessing antidepressant effectiveness via different approaches. Some are easy to implement, such as ecological measures, qualitative approaches, improvement of analytical strategy and improvement of blinding procedures. Some are sophisticated, involving temporary deception to deal with the confounding effect of expectations, and they raise ethical issues. Others resort to external validity, this being the case in observational studies. But all are necessary to explore antidepressant effectiveness.

  12. Identification and validation of reference genes for quantitative real-time PCR studies in long yellow daylily, Hemerocallis citrina Borani

    PubMed Central

    Wang, Jinyao; Kang, Xiuping; Weng, Yiqun

    2017-01-01

    Gene expression analysis using reverse transcription quantitative real-time PCR (RT-qPCR) requires the use of reference gene(s) in the target species. The long yellow daylily, Hemerocallis citrina Baroni. is rich in beneficial secondary metabolites and is considered as a functional vegetable. It is widely cultivated and consumed in East Asian countries. However, reference genes for use in RT-qPCR in H. citrina are not available. In the present study, six potential reference genes, actin (ACT), AP-4 complex subunit (AP4), tubulin (TUB), ubiquitin (UBQ), 18S and 60S ribosomal RNA, were selected and their expression stability in different developmental stages, organs and accessions was evaluated using four statistical software packages (geNorm, NormFinder, BestKeeper, and RefFinder). For commercial flower buds of different landraces, the combination of 60S, TUB, and AP4 was appropriate whereas ACT and 60S was suitable for normalization of different organs. In addition, AP4 exhibited the most stable expression in flower buds among different developmental stages. UBQ was less stable than the other reference genes under the experimental conditions except under different organs was 18S. The relative expression levels of two genes, primary-amine oxidase (HcAOC3) and tyrosine aminotransferase (HcTAT) which play important roles in alkaloid biosynthesis were also examined in different organs of the ‘Datong’ landrace, which further confirmed the results of selected reference genes. This is the first report to evaluate the stability of reference genes in the long yellow daylily that can serve as a foundation for RT-qPCR analysis of gene expression in this species. PMID:28362875

  13. Instructional Design: Case Studies in Communities of Practice

    ERIC Educational Resources Information Center

    Keppell, Michael, Ed.

    2007-01-01

    "Instructional Design: Case Studies in Communities of Practice" documents real-world experiences of instructional designers and staff developers who work in communities of practice. "Instructional Design: Case Studies in Communities of Practice" explains the strategies and heuristics used by instructional designers when working…

  14. Study of reduced order model reference adaptive control systems for improved process control. Final report, May 1, 1982-January 31, 1986

    SciTech Connect

    Hardt, D.E.; Papadpoulos, E.; Suzuki, A.

    1986-02-01

    The objective of this research is to provide a method for design of control systems when the plant involved is highly variable in both structure and parameter values. This typifies many manufacturing processes, which in general are highly sensitive to intrinsic properties of the infeed material, have poorly understood or controlled boundary conditions, and often have highly non-linear characteristics. In addition, the disturbances most frequent in a manufacturing process are best characterized as parameter changes rather than state variable changes. The choice of a parameter adaptive control paradigm is obvious since it has the property of optimizing system response characteristics in the face of wide plant parameter variations. Model Reference Adaptive Systems (MRAS) enjoy an ease of performance specification, and again seem applicable; however, there is a restriction within current theory that the plant be characterized in its structure well enough to have a reference model of identical order. This restriction implies a static plant structure and more a priori information than is often present. During this contract the basic design characteristics of certain MRAS have been studied and problems with reduced order models identified, such as noise and input magnitude sensitivity and instability caused by high frequency learning signals. This has lead to certain solutions and resulting guidelines for design. This is then followed by design studies for a position servomechanism (which serves as the foundation of many automated manufacturing processes). This study expanded the domain from MRAS to self-tuning controllers (STC) and found that both can deal with reduced order models if the initial parameter values are not too distant from the actual values. However, the STC appears to be the more robust. 12 refs., 56 figs.

  15. Design study of the storage ring EUTERPE

    NASA Astrophysics Data System (ADS)

    Xi, Boling; Botman, J. I. M.; Timmermans, C. J.; Hagedoorn, H. L.

    1992-05-01

    At present the 400 MeV electron storage ring EUTERPE is being constructed at the Eindhoven University of Technology. It is a university project set up for studies of charged particle beam dynamics and applications of synchroton radiation, and for the education of students in these fields. The design of the ring is described in this paper. Considering the requirements of users in different fields, a lattice based on a so-called triple bend achromat structure with a high flexibility has been chosen. With this lattice, different optical options, including the HBSB (high brightness, small beam), the SBL (short bunch length) and the HLF (high light flux) modes can be realized. A small emittance of 7 nm rad and a short bunch length of the order of several mm can be achieved. In the first phase the synchrotron radiation in the UV and XUV region (the critical wavelength is 8.3 nm) will be provided from the regular dipole magnets. Later on, a 10 T wiggler magnet and other special inserters will be added, and other applications and beam dynamics studies will be feasible. Bending magnets are of the parallel faced C configuration. The effective aperture of the vacuum chamber is 2.3 cm (vertical) in the bending magnets and 4.7 cm elsewhere with a working vacuum condition of 10-9 Torr. Collective effects have been studied initially. First calculations indicate that a lifetime of several hours, influenced by the Touschek effect and residual gas scattering will be achievable for a 200 mA beam in the HLF mode for the standard rf parameters. A 70 MeV racetrack microtron will serve as injector for the ring.

  16. Study of localized corrosion in aluminum alloys by the scanning reference electrode technique

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1995-01-01

    Localized corrosion in 2219-T87 aluminum (Al) alloy, 2195 aluminum-lithium (Al-Li) alloy, and welded 2195 Al-Li alloy (4043 filler) have been investigated using the relatively new scanning reference electrode technique (SRET). Anodic sites are more frequent and of greater strength in the 2195 Al-Li alloy than in the 2219-T87 Al alloy, indicating a greater tendency toward pitting for the latter. However, the overall corrosion rates are about the same for these two alloys, as determined using the polarization resistance technique. In the welded 2195 Al-Li alloy, the weld bean is entirely cathodic, with rather strongly anodic heat affected zones (HAZ) bordering both sides, indicating a high probability of corrosion in the HAZ parallel to the weld bead.

  17. Reference point indentation study of age-related changes in porcine femoral cortical bone.

    PubMed

    Rasoulian, Ramin; Raeisi Najafi, Ahmad; Chittenden, Michael; Jasiuk, Iwona

    2013-06-21

    The reference point indentation (RPI) method is a microindentation technique involving successive indentation cycles. We employed RPI to measure average stiffness (Ave US), indentation distance increase (IDI), total indentation distance (TID), average energy dissipated (Ave ED), and creep indentation distance (CID) of swine femoral cortical bone (mid-diaphysis) as a function of age (1, 3.5, 6, 14.5, 24, and 48 months) and loading directions (longitudinal and transverse). The Ave US increases with animal age, while the IDI, TID, Ave ED, and CID decrease with age, for both longitudinal (transverse surface) and transverse (periosteal surface) loading directions. Longitudinal measurements generally give higher Ave US and lower IDI and TID values compared to transverse measurements. The RPI measurements show similar trends to those obtained using nanoindentation test, and ash and water content tests.

  18. Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Quesada, A.; Camacho, A.; Rochera, C.; Velázquez, D.

    2009-11-01

    This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, ponds, rivers and wetlands; microbiology of microbial mats, ecology of microbial food webs and viral effects on aquatic ecosystems; ornithology, with investigations on a Gentoo penguin rookery ( Pygoscelis papua) as well as the flying ornithofauna; biocomplexity and life cycles of species from different taxonomic groups; analysis of a complete watershed unit from a landscape perspective; and human impacts, specifically the effect of trampling on soil characteristics and biota. Byers Peninsula offers many features as an international reference site given it is one of the largest ice-free areas in the Antarctic Peninsula region, it has a variety of different landscape units, and it hosts diverse aquatic ecosystems. Moreover, the Byers Peninsula is a hotspot for Antarctic biodiversity, and because of its high level of environmental protection, it has been very little affected by human activities. Finally, the proximity to the Spanish polar installations on Livingston Island and the experience derived from previous expeditions to the site make it logistically feasible as a site for ongoing monitoring and research.

  19. Intrasystem Analysis Program (IAP) Structural Design Study.

    DTIC Science & Technology

    1981-06-01

    34engineer" refers to a user with the usual basic electrical engineering education. An "experienced engineer" is one with adlditional experience in...Availability bility and user - bility and user - XTALK 2 5 ability codes ability codes available 20 available 20 ,21 Experience Engineer Engineer Engineer...LAl.’.d data; task; systems equations; emitter, receptor, and coupling models; computer resources; accuracy; and intended user . The attributes of

  20. Pharmacokinetic Studies in Infants Using Minimal-risk Study Designs

    PubMed Central

    Autmizguine, J; Benjamin, DK; Smith, PB; Sampson, M; Ovetchkine, P; Cohen-Wolkowiez, M.; Watt, KM

    2015-01-01

    Infants are therapeutic orphans. Many drugs used in infants are used “off-label”, increasing the risk of drug toxicity and suboptimal efficacy in this vulnerable population. This knowledge gap in clinical pharmacology is partly attributed to challenges associated with conducting clinical trials in infants. Consequently, there is a need for novel and efficient study designs more suited to this population. Available literature describing the use of minimal-risk approaches to characterize the pharmacokinetics (PK) of drugs in infants was critically reviewed. Population PK approach with sparse sampling was found to be well established. Other, more recent alternatives, like dried blood spots sampling, opportunistic design, and the use of non-blood matrices are promising strategies with an increasing number of applications in infants. Physiologically based pharmacokinetic modeling provides valuable insight in drug disposition but still needs more prospective validation. Increasing experience with these methods provides understanding of their strengths and limitations and will help improve the design of future PK studies in infants. PMID:24844642

  1. A Case Study in CAD Design Automation

    ERIC Educational Resources Information Center

    Lowe, Andrew G.; Hartman, Nathan W.

    2011-01-01

    Computer-aided design (CAD) software and other product life-cycle management (PLM) tools have become ubiquitous in industry during the past 20 years. Over this time they have continuously evolved, becoming programs with enormous capabilities, but the companies that use them have not evolved their design practices at the same rate. Due to the…

  2. New Study Designs | Division of Cancer Prevention

    Cancer.gov

    The Division of Cancer Prevention is expanding clinical research beyond standard trial designs to find interventions that may play a role in more than one prevalent disease. | The Division of Cancer Prevention is expanding clinical research beyond standard trial designs to find interventions that may play a role in more than one prevalent disease.

  3. Software design studies emphasizing Project LOGOS

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of a research project on the development of computer software are presented. Research funds of $200,000 were expended over a three year period for software design and projects in connection with Project LOGOS (computer-aided design and certification of computing systems). Abstracts of theses prepared during the project are provided.

  4. Low vision goggles: optical design studies

    NASA Astrophysics Data System (ADS)

    Levy, Ofer; Apter, Boris; Efron, Uzi

    2006-08-01

    Low Vision (LV) due to Age Related Macular Degeneration (AMD), Glaucoma or Retinitis Pigmentosa (RP) is a growing problem, which will affect more than 15 million people in the U.S alone in 2010. Low Vision Aid Goggles (LVG) have been under development at Ben-Gurion University and the Holon Institute of Technology. The device is based on a unique Image Transceiver Device (ITD), combining both functions of imaging and Display in a single chip. Using the ITD-based goggles, specifically designed for the visually impaired, our aim is to develop a head-mounted device that will allow the capture of the ambient scenery, perform the necessary image enhancement and processing, and re-direct it to the healthy part of the patient's retina. This design methodology will allow the Goggles to be mobile, multi-task and environmental-adaptive. In this paper we present the optical design considerations of the Goggles, including a preliminary performance analysis. Common vision deficiencies of LV patients are usually divided into two main categories: peripheral vision loss (PVL) and central vision loss (CVL), each requiring different Goggles design. A set of design principles had been defined for each category. Four main optical designs are presented and compared according to the design principles. Each of the designs is presented in two main optical configurations: See-through system and Video imaging system. The use of a full-color ITD-Based Goggles is also discussed.

  5. Gas cell based on optical contacting for fundamental spectroscopy studies with initial reference absorption spectrum of H2O vapor at 1723 K and 0.0235 bar

    NASA Astrophysics Data System (ADS)

    Melin, Scott T.; Sanders, Scott T.

    2016-09-01

    A gas cell, using optically contacted sapphire windows to form a hot vapor seal, has been created for high temperature fundamental spectroscopy studies. It is designed to operate at temperatures from 280-2273 K and pressures from vacuum to 1.3 bar. Using the cell in conjunction with an external cavity diode laser spectrometer, a reference H2O vapor absorption spectrum at P=0.0235±0.0036 bar and T=1723±6 K was measured with 0.0001 cm-1 resolution over the 7326-7598 cm-1 range. Comparison of the measured spectrum to simulations reveals errors in both the HITEMP and BT2 databases. This work establishes heated static cell capabilities at temperatures well above the typical limit of approximately 1300 K set by quartz material properties. This paper addresses the design of the cell as well as the cell's limitations.

  6. Sequence-based comparative study of classical swine fever virus genogroup 2.2 isolate with pestivirus reference strains

    PubMed Central

    Kumar, Ravi; Rajak, Kaushal Kishor; Chandra, Tribhuwan; Muthuchelvan, Dhanavelu; Saxena, Arpit; Chaudhary, Dheeraj; Kumar, Ajay; Pandey, Awadh Bihari

    2015-01-01

    Aim: This study was undertaken with the aim to compare and establish the genetic relatedness between classical swine fever virus (CSFV) genogroup 2.2 isolate and pestivirus reference strains. Materials and Methods: The available complete genome sequences of CSFV/IND/UK/LAL-290 strain and other pestivirus reference strains were retrieved from GenBank. The complete genome sequence, complete open reading frame, 5’ and 3’ non-coding region (NCR) sequences were analyzed and compared with reference pestiviruses strains. Clustal W model in MegAlign program of Lasergene 6.0 software was used for analysis of genetic heterogeneity. Phylogenetic analysis was carried out using MEGA 6.06 software package. Results: The complete genome sequence alignment of CSFV/IND/UK/LAL-290 isolate and reference pestivirus strains showed 58.9-72% identities at the nucleotide level and 50.3-76.9% at amino acid level. Sequence homology of 5’ and 3’ NCRs was found to be 64.1-82.3% and 22.9-71.4%, respectively. In phylogenetic analysis, overall tree topology was found similar irrespective of sequences used in this study; however, whole genome phylogeny of pestivirus formed two main clusters, which further distinguished into the monophyletic clade of each pestivirus species. CSFV/IND/UK/LAL-290 isolate placed with the CSFV Eystrup strain in the same clade with close proximity to border disease virus and Aydin strains. Conclusion: CSFV/IND/UK/LAL-290 exhibited the analogous genomic organization to those of all reference pestivirus strains. Based on sequence identity and phylogenetic analysis, the isolate showed close homology to Aydin/04-TR virus and distantly related to Bungowannah virus. PMID:27047198

  7. Ready Reference.

    ERIC Educational Resources Information Center

    Koltay, Emery

    1999-01-01

    Includes the following ready reference information: "Publishers' Toll-Free Telephone Numbers"; "How to Obtain an ISBN (International Standard Book Number)"; "How to Obtain an ISSN (International Standard Serial Number)"; and "How to Obtain an SAN (Standard Address Number)". (AEF)

  8. Design elements in implementation research: a structured review of child welfare and child mental health studies.

    PubMed

    Landsverk, John; Brown, C Hendricks; Rolls Reutz, Jennifer; Palinkas, Lawrence; Horwitz, Sarah McCue

    2011-01-01

    Implementation science is an emerging field of research with considerable penetration in physical medicine and less in the fields of mental health and social services. There remains a lack of consensus on methodological approaches to the study of implementation processes and tests of implementation strategies. This paper addresses the need for methods development through a structured review that describes design elements in nine studies testing implementation strategies for evidence-based interventions addressing mental health problems of children in child welfare and child mental health settings. Randomized trial designs were dominant with considerable use of mixed method designs in the nine studies published since 2005. The findings are discussed in reference to the limitations of randomized designs in implementation science and the potential for use of alternative designs.

  9. Is the cerebellum the optimal reference region for intensity normalization of perfusion MR studies in early Alzheimer's disease?

    PubMed

    Lacalle-Aurioles, María; Alemán-Gómez, Yasser; Guzmán-De-Villoria, Juan Adán; Cruz-Orduña, Isabel; Olazarán, Javier; Mateos-Pérez, José María; Martino, María Elena; Desco, Manuel

    2013-01-01

    The cerebellum is the region most commonly used as a reference when normalizing the intensity of perfusion images acquired using magnetic resonance imaging (MRI) in Alzheimer's disease (AD) studies. In addition, the cerebellum provides unbiased estimations with nuclear medicine techniques. However, no reports confirm the cerebellum as an optimal reference region in MRI studies or evaluate the consequences of using different normalization regions. In this study, we address the effect of using the cerebellum, whole-brain white matter, and whole-brain cortical gray matter in the normalization of cerebral blood flow (CBF) parametric maps by comparing patients with stable mild cognitive impairment (MCI), patients with AD and healthy controls. According to our results, normalization by whole-brain cortical gray matter enables more sensitive detection of perfusion abnormalities in AD patients and reveals a larger number of affected regions than data normalized by the cerebellum or whole-brain white matter. Therefore, the cerebellum is not the most valid reference region in MRI studies for early stages of AD. After normalization by whole-brain cortical gray matter, we found a significant decrease in CBF in both parietal lobes and an increase in CBF in the right medial temporal lobe. We found no differences in perfusion between patients with stable MCI and healthy controls either before or after normalization.

  10. Is the Cerebellum the Optimal Reference Region for Intensity Normalization of Perfusion MR Studies in Early Alzheimer’s Disease?

    PubMed Central

    Lacalle-Aurioles, María; Alemán-Gómez, Yasser; Guzmán-De-Villoria, Juan Adán; Cruz-Orduña, Isabel; Olazarán, Javier; Mateos-Pérez, José María; Martino, María Elena; Desco, Manuel

    2013-01-01

    The cerebellum is the region most commonly used as a reference when normalizing the intensity of perfusion images acquired using magnetic resonance imaging (MRI) in Alzheimer’s disease (AD) studies. In addition, the cerebellum provides unbiased estimations with nuclear medicine techniques. However, no reports confirm the cerebellum as an optimal reference region in MRI studies or evaluate the consequences of using different normalization regions. In this study, we address the effect of using the cerebellum, whole-brain white matter, and whole-brain cortical gray matter in the normalization of cerebral blood flow (CBF) parametric maps by comparing patients with stable mild cognitive impairment (MCI), patients with AD and healthy controls. According to our results, normalization by whole-brain cortical gray matter enables more sensitive detection of perfusion abnormalities in AD patients and reveals a larger number of affected regions than data normalized by the cerebellum or whole-brain white matter. Therefore, the cerebellum is not the most valid reference region in MRI studies for early stages of AD. After normalization by whole-brain cortical gray matter, we found a significant decrease in CBF in both parietal lobes and an increase in CBF in the right medial temporal lobe. We found no differences in perfusion between patients with stable MCI and healthy controls either before or after normalization. PMID:24386081

  11. Argonne Tau-charm factory collider design study

    SciTech Connect

    Teng, L.C.; Crosbie, E.A.; Norem, J.

    1995-12-01

    The design approach and design principles for a Tau-charm Factory at Argonne were studied. These studies led to a set of preliminary parameters and tentative component features as presented in this paper.

  12. PLUTONIUM-238 PRODUCTION TARGET DESIGN STUDIES

    SciTech Connect

    Hurt, Christopher J; Wham, Robert M; Hobbs, Randall W; Owens, R Steven; Chandler, David; Freels, James D; Maldonado, G Ivan

    2014-01-01

    A new supply chain is planned for plutonium-238 using existing reactors at the Oak Ridge National Laboratory (ORNL) and Idaho National Laboratory (INL) and existing chemical recovery facilities at ORNL. Validation and testing activities for new irradiation target designs have been conducted in three phases over a 2 year period to provide data for scale-up to production. Target design, qualification, target fabrication, and irradiation of fully-loaded targets have been accomplished. Data from post-irradiation examination (PIE) supports safety analysis and irradiation of future target designs.

  13. A study of commuter airplane design optimization

    NASA Technical Reports Server (NTRS)

    Keppel, B. V.; Eysink, H.; Hammer, J.; Hawley, K.; Meredith, P.; Roskam, J.

    1978-01-01

    The usability of the general aviation synthesis program (GASP) was enhanced by the development of separate computer subroutines which can be added as a package to this assembly of computerized design methods or used as a separate subroutine program to compute the dynamic longitudinal, lateral-directional stability characteristics for a given airplane. Currently available analysis methods were evaluated to ascertain those most appropriate for the design functions which the GASP computerized design program performs. Methods for providing proper constraint and/or analysis functions for GASP were developed as well as the appropriate subroutines.

  14. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    DOE PAGES

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, suchmore » as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.« less

  15. In-SEM Raman microspectroscopy coupled with EDX--a case study of uranium reference particles.

    PubMed

    Stefaniak, Elżbieta A; Pointurier, Fabien; Marie, Olivier; Truyens, Jan; Aregbe, Yetunde

    2014-02-07

    Information about the molecular composition of airborne uranium-bearing particles may be useful as an additional tool for nuclear safeguards. In order to combine the detection of micrometer-sized particles with the analysis of their molecular forms, we used a hybrid system enabling Raman microanalysis in high vacuum inside a SEM chamber (SEM-SCA system). The first step involved an automatic scan of a sample to detect and save coordinates of uranium particles, along with X-ray microanalysis. In the second phase, the detected particles were relocated in a white light image and subjected to Raman microanalysis. The consecutive measurements by the two beams showed exceptional fragility of uranium particles, leading to their ultimate damage and change of uranium oxidation state. We used uranium reference particles prepared by hydrolysis of uranium hexafluoride to test the reliability of the Raman measurements inside the high vacuum. The results achieved by the hybrid system were verified by using a standalone Raman microspectrometer. When deposited on exceptionally smooth substrates, uranyl fluoride particles smaller than 1000 nm could successfully be analyzed with the SEM-SCA system.

  16. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    SciTech Connect

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, such as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.

  17. Empirical studies of software design: Implications for SSEs

    NASA Technical Reports Server (NTRS)

    Krasner, Herb

    1988-01-01

    Implications for Software Engineering Environments (SEEs) are presented in viewgraph format for characteristics of projects studied; significant problems and crucial problem areas in software design for large systems; layered behavioral model of software processes; implications of field study results; software project as an ecological system; results of the LIFT study; information model of design exploration; software design strategies; results of the team design study; and a list of publications.

  18. Mars orbiter conceptual systems design study

    NASA Technical Reports Server (NTRS)

    Dixon, W.; Vogl, J.

    1982-01-01

    Spacecraft system and subsystem designs at the conceptual level to perform either of two Mars Orbiter missions, a Climatology Mission and an Aeronomy Mission were developed. The objectives of these missions are to obtain and return data.

  19. Identification of Reference Genes for Quantitative Gene Expression Studies in a Non-Model Tree Pistachio (Pistacia vera L.).

    PubMed

    Moazzam Jazi, Maryam; Ghadirzadeh Khorzoghi, Effat; Botanga, Christopher; Seyedi, Seyed Mahdi

    2016-01-01

    The tree species, Pistacia vera (P. vera) is an important commercial product that is salt-tolerant and long-lived, with a possible lifespan of over one thousand years. Gene expression analysis is an efficient method to explore the possible regulatory mechanisms underlying these characteristics. Therefore, having the most suitable set of reference genes is required for transcript level normalization under different conditions in P. vera. In the present study, we selected eight widely used reference genes, ACT, EF1α, α-TUB, β-TUB, GAPDH, CYP2, UBQ10, and 18S rRNA. Using qRT-PCR their expression was assessed in 54 different samples of three cultivars of P. vera. The samples were collected from different organs under various abiotic treatments (cold, drought, and salt) across three time points. Several statistical programs (geNorm, NormFinder, and BestKeeper) were applied to estimate the expression stability of candidate reference genes. Results obtained from the statistical analysis were then exposed to Rank aggregation package to generate a consensus gene rank. Based on our results, EF1α was found to be the superior reference gene in all samples under all abiotic treatments. In addition to EF1α, ACT and β-TUB were the second best reference genes for gene expression analysis in leaf and root. We recommended β-TUB as the second most stable gene for samples under the cold and drought treatments, while ACT holds the same position in samples analyzed under salt treatment. This report will benefit future research on the expression profiling of P. vera and other members of the Anacardiaceae family.

  20. Identification of Reference Genes for Quantitative Gene Expression Studies in a Non-Model Tree Pistachio (Pistacia vera L.)

    PubMed Central

    Moazzam Jazi, Maryam; Ghadirzadeh Khorzoghi, Effat; Botanga, Christopher; Seyedi, Seyed Mahdi

    2016-01-01

    The tree species, Pistacia vera (P. vera) is an important commercial product that is salt-tolerant and long-lived, with a possible lifespan of over one thousand years. Gene expression analysis is an efficient method to explore the possible regulatory mechanisms underlying these characteristics. Therefore, having the most suitable set of reference genes is required for transcript level normalization under different conditions in P. vera. In the present study, we selected eight widely used reference genes, ACT, EF1α, α-TUB, β-TUB, GAPDH, CYP2, UBQ10, and 18S rRNA. Using qRT-PCR their expression was assessed in 54 different samples of three cultivars of P. vera. The samples were collected from different organs under various abiotic treatments (cold, drought, and salt) across three time points. Several statistical programs (geNorm, NormFinder, and BestKeeper) were applied to estimate the expression stability of candidate reference genes. Results obtained from the statistical analysis were then exposed to Rank aggregation package to generate a consensus gene rank. Based on our results, EF1α was found to be the superior reference gene in all samples under all abiotic treatments. In addition to EF1α, ACT and β-TUB were the second best reference genes for gene expression analysis in leaf and root. We recommended β-TUB as the second most stable gene for samples under the cold and drought treatments, while ACT holds the same position in samples analyzed under salt treatment. This report will benefit future research on the expression profiling of P. vera and other members of the Anacardiaceae family. PMID:27308855