Science.gov

Sample records for concept le cycle

  1. Life cycle planning: An evolving concept

    SciTech Connect

    Moore, P.J.R.; Gorman, I.G.

    1994-12-31

    Life-cycle planning is an evolving concept in the management of oil and gas projects. BHP Petroleum now interprets this idea to include all development planning from discovery and field appraisal to final abandonment and includes safety, environmental, technical, plant, regulatory, and staffing issues. This article describes in the context of the Timor Sea, how despite initial successes and continuing facilities upgrades, BHPP came to perceive that current operations could be the victim of early development successes, particularly in the areas of corrosion and maintenance. The search for analogies elsewhere lead to the UK North Sea, including the experiences of Britoil and BP, both of which performed detailed Life of Field studies in the later eighties. These materials have been used to construct a format and content for total Life-cycle plans in general and the social changes required to ensure their successful application in Timor Sea operations and deployment throughout Australia.

  2. Supercritical Brayton Cycle Nuclear Power System Concepts

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.

    2007-01-01

    Both the NASA and DOE have programs that are investigating advanced power conversion cycles for planetary surface power on the moon or Mars, and for next generation nuclear power plants on earth. The gas Brayton cycle offers many practical solutions for space nuclear power systems and was selected as the nuclear power system of choice for the NASA Prometheus project. An alternative Brayton cycle that offers high efficiency at a lower reactor coolant outlet temperature is the supercritical Brayton cycle (SCBC). The supercritical cycle is a true Brayton cycle because it uses a single phase fluid with a compressor inlet temperature that is just above the critical point of the fluid. This paper describes the use of a supercritical Brayton cycle that achieves a cycle efficiency of 26.6% with a peak coolant temperature of 750 K and for a compressor inlet temperature of 390 K. The working fluid uses a clear odorless, nontoxic refrigerant C318 perflurocarbon (C4F8) that always operates in the gas phase. This coolant was selected because it has a critical temperature and pressure of 388.38 K and 2.777 MPa. The relatively high critical temperature allows for efficient thermal radiation that keeps the radiator mass small. The SCBC achieves high efficiency because the loop design takes advantage of the non-ideal nature of the coolant equation of state just above the critical point. The lower coolant temperature means that metal fuels, uranium oxide fuels, and uranium zirconium hydride fuels with stainless steel, ferretic steel, or superalloy cladding can be used with little mass penalty or reduction in cycle efficiency. The reactor can use liquid-metal coolants and no high temperature heat exchangers need to be developed. Indirect gas cooling or perhaps even direct gas cooling can be used if the C4F8 coolant is found to be sufficiently radiation tolerant. Other fluids can also be used in the supercritical Brayton cycle including Propane (C3H8, Tcritical = 369 K) and Hexane (C6

  3. Supercritical Brayton Cycle Nuclear Power System Concepts

    SciTech Connect

    Wright, Steven A.

    2007-01-30

    Both the NASA and DOE have programs that are investigating advanced power conversion cycles for planetary surface power on the moon or Mars, and for next generation nuclear power plants on earth. The gas Brayton cycle offers many practical solutions for space nuclear power systems and was selected as the nuclear power system of choice for the NASA Prometheus project. An alternative Brayton cycle that offers high efficiency at a lower reactor coolant outlet temperature is the supercritical Brayton cycle (SCBC). The supercritical cycle is a true Brayton cycle because it uses a single phase fluid with a compressor inlet temperature that is just above the critical point of the fluid. This paper describes the use of a supercritical Brayton cycle that achieves a cycle efficiency of 26.6% with a peak coolant temperature of 750 K and for a compressor inlet temperature of 390 K. The working fluid uses a clear odorless, nontoxic refrigerant C318 perflurocarbon (C4F8) that always operates in the gas phase. This coolant was selected because it has a critical temperature and pressure of 388.38 K and 2.777 MPa. The relatively high critical temperature allows for efficient thermal radiation that keeps the radiator mass small. The SCBC achieves high efficiency because the loop design takes advantage of the non-ideal nature of the coolant equation of state just above the critical point. The lower coolant temperature means that metal fuels, uranium oxide fuels, and uranium zirconium hydride fuels with stainless steel, ferretic steel, or superalloy cladding can be used with little mass penalty or reduction in cycle efficiency. The reactor can use liquid-metal coolants and no high temperature heat exchangers need to be developed. Indirect gas cooling or perhaps even direct gas cooling can be used if the C4F8 coolant is found to be sufficiently radiation tolerant. Other fluids can also be used in the supercritical Brayton cycle including Propane (C3H8, Tcritical = 369 K) and Hexane (C6

  4. Le concept de banque d'items et ses implications sur le contenu didactique

    NASA Astrophysics Data System (ADS)

    Tistaert, G.; Mwene, Magabe

    1985-12-01

    The development of the concept of an item bank comes as a reply to the didactic situations which for reasons of efficiency require the storing of a number of susceptible items to be used at any time. Access to the computer makes possible an improvement and rationalization of the management of the item bank. At the same time the extension of the concept has followed two main directions. On the one hand, particular care relates to the adequacy of stored items with the content of learning and it brings about the emergence of a technology of item-editing. On the other hand, psychometric considerations have caused the invariance of essential characteristics of the items. This demands that the items respond to the presupposed models with latent traits. On the basis of theoretical arguments supported by some research findings the final part of the article calls attention to the deep discord among researchers concerning the reliability of the presuppositions of these models in the didactic field. The compromise will probably lead to it that the multidimensionality of items which have a didactic character are admitted.

  5. Self Concept Development through the Adult Life Cycle.

    ERIC Educational Resources Information Center

    Lynch, Mervin D.; Lynch, Carol Lee

    1991-01-01

    The developmental model of self-concept proposed by M. Lynch and M. Levy (1982) is extended through the entire adult life cycle. Self-concept is seen as a set of cognitive rules that have affective or cognitive consequences and that operate like the ego functions proposed by Freud. (SLD)

  6. Integrating Concept Mapping and the Learning Cycle To Teach Diffusion and Osmosis Concepts to High School Biology Students.

    ERIC Educational Resources Information Center

    Odom, Arthur L.; Kelly, Paul V.

    2001-01-01

    Explores the effectiveness of concept mapping, the learning cycle, expository instruction, and a combination of concept mapping/learning cycle in promoting conceptual understanding of diffusion and osmosis. Concludes that the concept mapping/learning cycle and concept mapping treatment groups significantly outperformed the expository treatment…

  7. Integrating the disaster cycle model into traditional disaster diplomacy concepts.

    PubMed

    Callaway, David W; Yim, Eugene S; Stack, Colin; Burkle, Frederick M

    2012-03-01

    Disaster diplomacy is an evolving contemporary model that examines how disaster response strategies can facilitate cooperation between parties in conflict. The concept of disaster diplomacy has emerged during the past decade to address how disaster response can be leveraged to promote peace, facilitate communication, promote human rights, and strengthen intercommunity ties in the increasingly multipolar modern world. Historically, the concept has evolved through two camps, one that focuses on the interactions between national governments in conflict and another that emphasizes the grassroots movements that can promote change. The two divergent approaches can be reconciled and disaster diplomacy further matured by contextualizing the concept within the disaster cycle, a model well established within the disaster risk management community. In particular, access to available health care, especially for the most vulnerable populations, may need to be negotiated. As such, disaster response professionals, including emergency medicine specialists, can play an important role in the development and implementation of disaster diplomacy concepts.

  8. Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles

    SciTech Connect

    Hardin, Ernest; Blink, James; Carter, Joe; Massimiliano, Fratoni; Greenberg, Harris; Howard, Rob L

    2011-01-01

    The current posture of the used nuclear fuel management program in the U.S. following termination of the Yucca Mountain Project, is to pursue research and development (R&D) of generic (i.e., non-site specific) technologies for storage, transportation and disposal. Disposal R&D is directed toward understanding and demonstrating the performance of reference geologic disposal concepts selected to represent the current state-of-the-art in geologic disposal. One of the principal constraints on waste packaging and emplacement in a geologic repository is management of the waste-generated heat. This paper describes the selection of reference disposal concepts, and thermal management strategies for waste from advanced fuel cycles. A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE) Used Fuel Disposition Campaign, for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. We performed thermal analysis of these concepts using waste inventory cases representing a range of advanced fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress and previous experience in the U.S. repository program. All of the disposal concepts selected for this study use enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. The encapsulating materials (typically clay-based or rock salt) have low intrinsic permeability and plastic rheology that closes voids so that low permeability is maintained. Uniformly low permeability also contributes to chemically reducing conditions common in soft clay, shale, and salt formations. Enclosed modes are associated

  9. Concepts and Tools for the Software Life Cycle

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.

    1985-01-01

    The tools, techniques, and aids needed to engineer, manage, and administer a large software-intensive task are themselves parts of a large softwaare base, and are incurred only at great expense. The needs of the software life cycle in terms of such supporting tools and methodologies are highlighted. The concept of a distributed network for engineering, management, and administrative functions is outlined, and the key characteristics of localized subnets in high-communications-traffic areas of software activity are discussed. A formal, deliberate, structured, systems-engineering approach for the construction of a uniform, coordinated tool set is proposed as a means to reduce development and maintenance costs, foster adaptability, enhance reliability, and promote standardization.

  10. Concepts and tools for the software life cycle

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.

    1985-01-01

    The tools, techniques, and aids needed to engineer, manage, and administer a large software-intensive task are themselves parts of a large software base, and are incurred only at great expense. The needs of the software life cycle in terms of such supporting tools and methodologies are highlighted. The concept of a distributed network for engineering, management, and administrative functions is outlined, and the key characteristics of localized subnets in high-communications-traffic areas of software actively are discussed. A formal, deliberate, structured, systems-engineering approach for the construction of a uniform, coordinated tool set is proposed as a means to reduce development and maintenance costs, foster adaptability, enhance reliability, and promote standardization.

  11. Concept of DT fuel cycle for a fusion neutron source

    SciTech Connect

    Anan'ev, S.; Spitsyn, A.V.; Kuteev, B.V.; Cherkez, D.I.; Shirnin, P.N.; Kazakovsky, N.T.

    2015-03-15

    A concept of DT-fusion neutron source (FNS) with the neutron yield higher than 10{sup 18} neutrons per second is under design in Russia. Such a FNS is of interest for many applications: 1) basic and applied research (neutron scattering, etc); 2) testing the structural materials for fusion reactors; 3) control of sub-critical nuclear systems and 4) nuclear waste processing (including transmutation of minor actinides). This paper describes the fuel cycle concept of a compact fusion neutron source based on a small spherical tokamak (FNS-ST) with a MW range of DT fusion power and considers the key physics issues of this device. The major and minor radii are ∼0.5 and ∼0.3 m, magnetic field ∼1.5 T, heating power less than 15 MW and plasma current 1-2 MA. The system provides the fuel mixture with equal fractions of D and T (D:T = 1:1) for all FNS technology systems. (authors)

  12. Some heat pump concepts for residual heat utilization. [Absorption-cycle and open-cycle systems

    SciTech Connect

    Perez-Blanco, H.; Chen, F. C.

    1980-01-01

    Large quantities of low temperature heat in the industrial sector are rejected in the cooling water, condensate, and process water streams. While the energy rejected in these streams at temperatures between 40 and 80/sup 0/C amounts to 2.95 x 10/sup 9/ GJ/y, 2.42 x 10/sup 9/ GJ/y of process energy in the form of hot water and steam are needed in the United States. Industrial heat pumps, that recover the low temperature heat energy and upgrade it to a more usable temperature level, may improve the energy supply and demand situation. Two heat activated heat pump concepts - an absorption cycle system and an open cycle system are analyzed from the conceptual systems design and energy savings point of view. The results of the analysis and further research needs are presented.

  13. Integral fast reactor concept. [Pool type; metal fuel; integral fuel cycle

    SciTech Connect

    Chang, Y.I.; Marchaterre, J.F.; Sevy, R.H.

    1984-01-01

    Key features of the IFR consist of a pool-type plant arrangement, a metal fuel-based core design, and an integral fuel cycle with colocated fuel cycle facility. Both the basic concept and the technology base have been demonstrated through actual integral cycle operation in EBR-II. This paper discusses the inherent safety characteristics of the IFR concept. (DLC)

  14. Rocket-Based Combined Cycle Engine Concept Development

    NASA Technical Reports Server (NTRS)

    Ratekin, G.; Goldman, Allen; Ortwerth, P.; Weisberg, S.; McArthur, J. Craig (Technical Monitor)

    2001-01-01

    The development of rocket-based combined cycle (RBCC) propulsion systems is part of a 12 year effort under both company funding and contract work. The concept is a fixed geometry integrated rocket, ramjet, scramjet, which is hydrogen fueled and uses hydrogen regenerative cooling. The baseline engine structural configuration uses an integral structure that eliminates panel seals, seal purge gas, and closeout side attachments. Engine A5 is the current configuration for NASA Marshall Space Flight Center (MSFC) for the ART program. Engine A5 models the complete flight engine flowpath of inlet, isolator, airbreathing combustor, and nozzle. High-performance rocket thrusters are integrated into the engine enabling both low speed air-augmented rocket (AAR) and high speed pure rocket operation. Engine A5 was tested in GASL's new Flight Acceleration Simulation Test (FAST) facility in all four operating modes, AAR, RAM, SCRAM, and Rocket. Additionally, transition from AAR to RAM and RAM to SCRAM was also demonstrated. Measured performance demonstrated vision vehicle performance levels for Mach 3 AAR operation and ramjet operation from Mach 3 to 4. SCRAM and rocket mode performance was above predictions. For the first time, testing also demonstrated transition between operating modes.

  15. Vulnérologie: un néologisme pour magnifier le concept «plaies et cicatrisation»

    PubMed Central

    Costagliola, M.; Atiyeh, B.

    2016-01-01

    Summary Bien que la cicatrisation des plaies soit un thème médico-chirurgical essentiel depuis l’Antiquité, il a été longtemps négligé. L’essor dans ce domaine, ces 20 dernières années, de la recherche fondamentale et le développement de nouvelles techniques ont fait que la cicatrisation est devenue une entité à part entière, transversale, intéressant plusieurs spécialités. Il a semblé souhaitable, en nous appuyant sur des arguments étymologiques, sémantiques et botaniques, de proposer un néologisme pour regrouper sous une même appellation tous les professionnels de santé oeuvrant dans ce secteur de soins et magnifier ainsi le concept « Plaies et Cicatrisation ». PMID:28149240

  16. Closed Cycle Cryocooler for Low Temperature Electronic Circuits. Phase I. Concept Study

    DTIC Science & Technology

    1980-11-01

    4 III. METHOD OF" APPROACH, MODELING TECHNIQUE .. .. .... .......... ... 6 Modeling of Stirling Cycle...results of the Phase I study to develop concepts for closed cycle cryocoolers for low temperature electronic circuits. Technical contributions to the...conceptual study of small, low power, very low magnetic signature, lightweight, efficient closed cycle, cryocoolers suitable for use with superconductive and

  17. Technology Insights and Perspectives for Nuclear Fuel Cycle Concepts

    SciTech Connect

    S. Bays; S. Piet; N. Soelberg; M. Lineberry; B. Dixon

    2010-09-01

    The following report provides a rich resource of information for exploring fuel cycle characteristics. The most noteworthy trends can be traced back to the utilization efficiency of natural uranium resources. By definition, complete uranium utilization occurs only when all of the natural uranium resource can be introduced into the nuclear reactor long enough for all of it to undergo fission. Achieving near complete uranium utilization requires technologies that can achieve full recycle or at least nearly full recycle of the initial natural uranium consumed from the Earth. Greater than 99% of all natural uranium is fertile, and thus is not conducive to fission. This fact requires the fuel cycle to convert large quantities of non-fissile material into fissile transuranics. Step increases in waste benefits are closely related to the step increase in uranium utilization going from non-breeding fuel cycles to breeding fuel cycles. The amount of mass requiring a disposal path is tightly coupled to the quantity of actinides in the waste stream. Complete uranium utilization by definition means that zero (practically, near zero) actinide mass is present in the waste stream. Therefore, fuel cycles with complete (uranium and transuranic) recycle discharge predominately fission products with some actinide process losses. Fuel cycles without complete recycle discharge a much more massive waste stream because only a fraction of the initial actinide mass is burned prior to disposal. In a nuclear growth scenario, the relevant acceptable frequency for core damage events in nuclear reactors is inversely proportional to the number of reactors deployed in a fuel cycle. For ten times the reactors in a fleet, it should be expected that the fleet-average core damage frequency be decreased by a factor of ten. The relevant proliferation resistance of a fuel cycle system is enhanced with: decreasing reliance on domestic fuel cycle services, decreasing adaptability for technology misuse

  18. Representations des eleves de l'ecole maternelle: Le concept de lumiere. [Preschoolers' Representations: The Concept of Light].

    ERIC Educational Resources Information Center

    Ravanis, Konstantinos

    1999-01-01

    Studied the ideas of 5-year olds regarding the concept of light, using individual interviews. Found that children identify light with its source or its effect rather than as a distinct entity, a representation at odds with the scientific concept of light. (Author/JPB)

  19. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    SciTech Connect

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  20. Supercritical CO2 direct cycle Gas Fast Reactor (SC-GFR) concept.

    SciTech Connect

    Wright, Steven Alan; Parma, Edward J., Jr.; Suo-Anttila, Ahti Jorma; Al Rashdan, Ahmad; Tsvetkov, Pavel Valeryevich; Vernon, Milton E.; Fleming, Darryn D.; Rochau, Gary Eugene

    2011-05-01

    This report describes the supercritical carbon dioxide (S-CO{sub 2}) direct cycle gas fast reactor (SC-GFR) concept. The SC-GFR reactor concept was developed to determine the feasibility of a right size reactor (RSR) type concept using S-CO{sub 2} as the working fluid in a direct cycle fast reactor. Scoping analyses were performed for a 200 to 400 MWth reactor and an S-CO{sub 2} Brayton cycle. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this report show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The concept is based largely on the Advanced Gas Reactor (AGR) commercial power plants operated in the United Kingdom and other GFR concepts.

  1. Application of the N-Streaming SM concept to Peach Bottom 2 Cycle 17

    SciTech Connect

    Asgari, M.; Kropaczek, D. J.; Oyarzun, C. C.

    2006-07-01

    This paper discusses the application of the N-Streaming concept developed at Global Nuclear Fuel for the design of a Boiling Water Reactor (BWR) fuel cycle. The paper presents the N-Streaming concept and discusses the application of N-Streaming to the recent fuel cycle for Peach Bottom Unit 2 Cycle 17. It is demonstrated that the application of N-Streaming provides extra design freedom to optimize design margins allowing better operational flexibility while reducing the fuel cycle cost. (authors)

  2. Changing Pre-School Children's Conceptions of the Day/Night Cycle.

    ERIC Educational Resources Information Center

    Valanides, N.; Gritsi, F.; Kampeza, M.; Ravanis, K.

    2000-01-01

    Examined the impact of a teaching intervention on preschoolers' concepts of the day/night cycle. Found that most children readily accepted that the sun and earth are separate spherical objects, but fewer attributed the day/night cycle to rotation of the earth on its axis. Most were puzzled by simultaneous movements of the earth around the sun and…

  3. Application of Program Life Cycle Concepts for Fund Raising Strategies in Higher Education.

    ERIC Educational Resources Information Center

    Hekmat, Firooz; Heischmidt, Kenneth A.

    1993-01-01

    The concept of program life-cycle management is applied to college fund raising. Program life-cycle stages (introduction, take-off, maturation, saturation, decline) and fund-raising steps (identification of objectives, targeting of markets, estimate potential for contribution, organization, strategy development, fund-raising performance…

  4. Why Do Athletes Drink Sports Drinks? A Learning Cycle to Explore the Concept of Osmosis

    ERIC Educational Resources Information Center

    Carlsen, Brook; Marek, Edmund A.

    2010-01-01

    Why does an athlete reach for a sports drink after a tough game or practice? The learning cycle presented in this article helps students answer this question. Learning cycles (Marek 2009) are designed to guide students through direct experiences with a particular concept. In this article, students learn about "osmosis," or the moving of water into…

  5. Historical constraints on the origins of the carbon cycle concept

    NASA Astrophysics Data System (ADS)

    Galvez, Matthieu Emmanuel; Gaillardet, Jérôme

    2012-11-01

    Understanding the geological carbon cycle remains a major scientific challenge, although studies dedicated to this issue, in particular those of J.J. Ebelmen in the mid 19th century, have existed for over 200 years. The exact scientific and social pathways leading to the construction of the contemporaneous carbon cycle requires further investigation, which in turn may provide valuable insights into the modern state of scientific knowledge. The present study contributes to this question by demonstrating that, following the discovery of the compound nature of carbonic acid by A.L. Lavoisier at the end of the 18th century, studies initially investigated the mechanisms of respiration and photosynthesis until they were recognized as exerting an antagonistic effect on the composition of air. In the early 19th century, the consequence of these studies at the global scale had been foreseen, and applied to investigate the stability of the atmospheric composition over time. These early steps were only concerned with the fate of carbonic acid through life processes. However, between 1820 and 1840, the works of A.L. Brongniard and J.B. Boussingault established that geologic processes, such as the burial of carbonaceous material (CM) in sedimentary rocks and the release of CO2 by volcanoes, affect the composition of the atmosphere. By 1845, J.J. Ebelmen had brilliantly contributed to the emerging question of atmospheric composition by proposing that the alteration of silicates on continents and the precipitation of carbonates in the ocean should be considered as a sink of atmospheric CO2. He also used chemical formula of the time to quantify this process, which led him to mention a carbon rotation for the first time. The rotation of this element through geologic processes became, in itself, a matter worthy of investigation as was the composition of the atmosphere. We argue that J.J. Ebelmen's brilliant synthesis was made possible by the parallel development of the atomistic

  6. Impact du réchauffement climatique sur le cycle hydrologique

    NASA Astrophysics Data System (ADS)

    Planton, Serge; Déqué, Michel; Douville, Hervé; Spagnoli, Bruno

    2005-02-01

    At the planetary scale, the models consistently simulate an intensification of the hydrological cycle in a future climate, warmer than the present-day one. However, this intensification might be accompanied by its slowing down due to an increase of the residence time of water vapour in the atmosphere. The impact of climate change on extreme events is even more difficult to evaluate, as results are dependent on methods, emission scenarios and, above all, on models. However, the increase of extreme winter precipitation over northern Europe is a common feature of these evaluations. The hydrological cycle, through the geographical distribution of continental surface humidity, seems to play a key role on the possibility to detect the warming in France. To cite this article: S. Planton et al., C. R. Geoscience 337 (2005).

  7. The importance of life cycle concepts for the development of safe nanoproducts.

    PubMed

    Som, Claudia; Berges, Markus; Chaudhry, Qasim; Dusinska, Maria; Fernandes, Teresa F; Olsen, Stig I; Nowack, Bernd

    2010-03-10

    Whilst the global players in industry are rapidly moving forward to take advantage of the new opportunities and prospects offered by nanotechnologies, it is imperative that such developments take place in a safe and sustainable manner. The increasing use of engineered nanomaterials (ENMs) in consumer products has raised certain concerns over their safety to human health and the environment. There are currently a number of major uncertainties and knowledge gaps in regard to behavior, chemical and biological interactions and toxicological properties of ENMs. As dealing with these uncertainties will require the generation of new basic knowledge, it is unlikely that they will be resolved in the immediate future. One has to consider the whole life cycle of nanoproducts to ensure that possible impacts can be systematically discovered. For example, life cycle assessment (LCA) - a formalized life cycle concept - may be used to assess the relative environmental sustainability performance of nanoproducts in comparison with their conventional equivalents. Other less formalized life cycle concepts in the framework of prospective technology assessment may uncover further detailed and prospective knowledge for human and environmental exposure to ENMs during the life cycle of nanoproducts. They systematically reveal impacts such as cross product contamination or dissipation of scarce materials among others. The combination of different life cycle concepts with the evolving knowledge from toxicology and risk assessment can mitigate uncertainties and can provide an early basis for informed decision making by the industry and regulators.

  8. Bayesian selection of predictors of conception probabilities across the menstrual cycle.

    PubMed

    Scarpa, Bruno; Dunson, David B

    2006-11-01

    There is increasing interest in identifying predictors of human fertility, including environmental exposures, behavioural factors, and biomarkers, such as mucus or reproductive hormones. Epidemiological studies typically measure fecundability, the per menstrual cycle probability of conception, using time to pregnancy data. A critical predictor, which is often ignored in the design or analysis, is the timing of non-contracepting intercourse in the menstrual cycle. In order to limit confounding by behavioural differences between exposure groups, it may be preferable to base inferences on day-specific conception probabilities in relation to intercourse timing. This article proposes Bayesian methods for selection of predictors of day-specific conception probabilities. A particular focus is the case in which data on ovulation timing are not available. We focus on the selection of fertile days in the cycle during which conception probabilities are non-negligible and predictors may play a role. Data from recent European and Italian prospective studies of daily fecundability are presented, and the proposed approach is used to estimate cervical mucus effects within a mid-cycle potentially fertile window using data from the Italian study.

  9. The UMR Conception Cycle of Vocational School Students in Solving Linear Equation

    ERIC Educational Resources Information Center

    Li, Shao-Ying; Leon, Shian

    2013-01-01

    The authors designed instruments from theories and literatures. Data were collected throughout remedial teaching processes and interviewed with vocational school students. By SOLO (structure of the observed learning outcome) taxonomy, the authors made the UMR (unistructural-multistructural-relational sequence) conception cycle of the formative and…

  10. Analysis of a New Rocket-Based Combined-Cycle Engine Concept at Low Speed

    NASA Technical Reports Server (NTRS)

    Yungster, S.; Trefny, C. J.

    1999-01-01

    An analysis of the Independent Ramjet Stream (IRS) cycle is presented. The IRS cycle is a variation of the conventional ejector-Ramjet, and is used at low speed in a rocket-based combined-cycle (RBCC) propulsion system. In this new cycle, complete mixing between the rocket and ramjet streams is not required, and a single rocket chamber can be used without a long mixing duct. Furthermore, this concept allows flexibility in controlling the thermal choke process. The resulting propulsion system is intended to be simpler, more robust, and lighter than an ejector-ramjet. The performance characteristics of the IRS cycle are analyzed for a new single-stage-to-orbit (SSTO) launch vehicle concept, known as "Trailblazer." The study is based on a quasi-one-dimensional model of the rocket and air streams at speeds ranging from lift-off to Mach 3. The numerical formulation is described in detail. A performance comparison between the IRS and ejector-ramjet cycles is also presented.

  11. Development and proof-testing of advanced absorption refrigeration cycle concepts

    SciTech Connect

    Modahl, R.J.; Hayes, F.C. . Applied Unitary/Refrigeration Systems Div.)

    1992-03-01

    The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

  12. Innovative turbine concepts for open-cycle OTEC (Ocean Thermal Energy Conversion)

    NASA Astrophysics Data System (ADS)

    1989-12-01

    The results are summarized of preliminary studies conducted to identify and evaluate three innovative concepts for an open cycle ocean thermal energy conversion (OTEC) steam turbine that could significantly reduce the cost of OTEC electrical power plants. The three concepts are: (1) a crossflow turbine, (2) a vertical axis, axial flow turbine, and (3) a double flow, radial inflow turbine with mixed flow blading. In all cases, the innovation involves the use of lightweight, composite plastic blading and a physical geometry that facilitates efficient fluid flow to and from the other major system components and reduces the structural requirements for both the turbine or the system vacuum enclosure, or both. The performance, mechanical design, and cost of each of the concepts are developed to varying degrees but in sufficient detail to show that the potential exists for cost reductions to the goals established in the U.S. Department of Energy's planning documents. Specifically, results showed that an axial turbine operating with 33 percent higher steam throughput and 7 percent lower efficiency than the most efficient configuration provides the most cost effective open-cycle OTEC system. The vacuum enclosure can be significantly modified to reduce costs by establishing better interfaces with the system.

  13. Innovative turbine concepts for open-cycle OTEC (ocean thermal energy conversion)

    SciTech Connect

    Not Available

    1989-12-01

    This report summarizes the results of preliminary studies conducted to identify and evaluate three innovative concepts for an open-cycle ocean thermal energy conversion (OTEC) steam turbine that could significantly reduce the cost of OTEC electrical power plants. The three concepts are (1) a crossflow turbine, (2) a vertical-axis, axial-flow turbine, and (3) a double-flow, radial-inflow turbine with mixed-flow blading. In all cases, the innovation involves the use of lightweight, composite plastic blading and a physical geometry that facilitates efficient fluid flow to and from the other major system components and reduces the structural requirements for both the turbine or the system vacuum enclosure, or both. The performance, mechanical design, and cost of each of the concepts are developed to varying degrees but in sufficient detail to show that the potential exists for cost reductions to the goals established in the US Department of Energy's planning documents. Specifically, results showed that an axial turbine operating with 33% higher steam throughput and 7% lower efficiency than the most efficient configuration provides the most cost-effective open-cycle OTEC system. The vacuum enclosure can be significantly modified to reduce costs by establishing better interfaces with the system. 33 refs., 26 figs., 11 tabs.

  14. L'Apprentissage et le Changement des Attitudes envers Soi-meme: Le Concept de Soi. (Learning and the Change of Attitudes Towards Oneself: Self Image).

    ERIC Educational Resources Information Center

    Leduc, Aimee

    1980-01-01

    The French language article is the second in a series and describes the principles of classic conditioning which underlie attitude formation and change. The article also notes the many functions of self-concept attitudes in order to guide the choices of intervention in attitude learning. (Author/SB)

  15. The concept of the sexual reproduction cycle and its evolutionary significance

    PubMed Central

    Bai, Shu-Nong

    2015-01-01

    The concept of a “sexual reproduction cycle (SRC)” was first proposed by Bai and Xu (2013) to describe the integration of meiosis, sex differentiation, and fertilization. This review discusses the evolutionary and scientific implications of considering these three events as part of a single process. Viewed in this way, the SRC is revealed to be a mechanism for efficiently increasing genetic variation, facilitating adaptation to environmental challenges. It also becomes clear that, in terms of cell proliferation, it is appropriate to contrast mitosis with the entire SRC, rather than with meiosis alone. Evolutionarily, it appears that the SRC was first established in unicellular eukaryotes and that all multicellular organisms evolved within that framework. This concept provides a new perspective into how sexual reproduction evolved, how generations should be defined, and how developmental processes of various multicellular organisms should properly be compared. PMID:25667590

  16. Executive Summary of Ares V: Lunar Capabilities Concept Review Through Phase A-Cycle 3

    NASA Technical Reports Server (NTRS)

    Holladay, J. B.; Baggett, K. E.; Feldman, S. M.

    2011-01-01

    This Technical Memorandum (TM) was generated as an overall Ares V summary from the Lunar Capabilities Concept Review (LCCR) through Phase A-Cycle 3 (PA-C3) with the intent that it may be coupled with separately published appendices for a more detailed, integrated narrative. The Ares V has evolved from the initial point of departure (POD) 51.00.48 LCCR configuration to the current candidate POD, PA-C3D, and the family of vehicles concept that contains vehicles PA-C3A through H. The logical progression from concept to POD vehicles is summarized in this TM and captures the trade space and performance of each. The family-of-vehicles concept was assessed during PA-C3 and offered flexibility in the path forward with the ability to add options deemed appropriate. A description of each trade space is given in addition to a summary of each Ares V element. The Ares V contributions to a Mars campaign are also highlighted with the goal of introducing Ares V capabilities within the trade space. The assessment of the Ares V vehicle as it pertains to Mars missions remained locked to the architecture presented in Mars Design Reference Authorization 5.0 using the PA-C3D vehicle configuration to assess Mars transfer vehicle options, in-space EDS capabilities, docking adaptor and propellant transfer assessments, and lunar and Mars synergistic potential.

  17. Using a Learning Cycle to Deepen Chinese Primary Students' Concept Learning of the "Phases of the Moon"

    ERIC Educational Resources Information Center

    Lin, Jing

    2016-01-01

    This study focuses on the internal conditions of students' concept learning and builds a learning cycle' based on the "phases of the Moon" (MP) to, deepen students' understanding. The learning cycle of MP developed in this study includes three basic learning links, which are: cognitive conflict, abstraction and generalization, and…

  18. Effectiveness of 5E Learning Cycle Instruction on Students' Achievement in Cell Concept and Scientific Epistemological Beliefs

    ERIC Educational Resources Information Center

    Kaynar, Devrim; Tekkaya, Ceren; Cakiroglu, Jale

    2009-01-01

    This study investigated the effectiveness of 5E learning cycle on 6th-grade students' achievement of cell concepts, and their scientific epistemological beliefs. Epistemological Belief Questionnaire and the Cell Concept Test were administered as pre-test and post-test to a total of 153 sixth grade students in four intact classes of an elementary…

  19. Water Transformation and Storage in the Mountains and at the Coast: Midwest Students' Disconnected Conceptions of the Hydrologic Cycle

    ERIC Educational Resources Information Center

    Shepardson, Daniel P.; Wee, Bryan; Priddy, Michelle; Schellenberger, Lauren; Harbor, Jon

    2009-01-01

    The purpose of the present study was to investigate students' conceptions of the hydrologic cycle and to examine whether these conceptions vary by grade level and community setting. This study was descriptive in nature and reflected a cross-age design involving the collection of qualitative data from 1,298 students from the Midwest, USA. These…

  20. In-reactor testing of the closed cycle gas core reactor: The Nuclear Light Bulb concept

    NASA Astrophysics Data System (ADS)

    Gauntt, R. O.; Slutz, S. A.; Harms, G. A.; Latham, T. S.; Roman, W. C.; Rodgers, R. J.

    1992-10-01

    The Nuclear Light Bulb (NLB) concept is an advanced closed cycle space propulsion rocket engine design that offers unprecidented performance characteristics in terms of specific impulse (greater than 1800 s) and thrust (greater than 445 kN). The NLB is a gas-core nuclear reactor making use of thermal radiation from a high temperature U-plasma core to heat the hydrogen propellant to very high temperatures (greater than 4000 K). Analyses performed in support of the design of in-reactor tests that are planned to be performed in the Annular Core Research Reactor (ACRR) at Sandia National Laboratories in order to demonstrate the technical feasibility of this advanced concept are described. The tests will examine the stability of a hydrodynamically confined fissioning U-plasma under steady and transient conditions. Testing will also involve study of propellant heating by thermal radiation from the plasma and materials performance in the nuclear environment of the NLB. The analyses presented include neutronic performance studies and U-plasma radiation heat-transport studies of small vortex-confined fissioning U-plasma experiments that are irradiated in the ACRE. These analyses indicate that high U-plasma temperatures (4000 to 9000 K) can be sustained in the ACRE for periods of time on the order of 5 to 20 s. These testing conditions are well suited to examine the stability and performance requirements necessary to demonstrate the feasibility of this concept.

  1. Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles - 12477

    SciTech Connect

    Hardin, Ernest; Blink, James; Carter, Joe; Fratoni, Massimiliano; Greenberg, Harris; Sutton, Mark; Howard, Robert

    2012-07-01

    A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE), Used Fuel Disposition campaign. Reference concepts are identified for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. These were analyzed for waste inventory cases representing a range of waste types that could be produced by advanced nuclear fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress. All of these disposal concepts are enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. Enclosed modes have less capacity to dissipate heat than open modes such as that proposed for a repository at Yucca Mountain. Thermal analysis has identified important relationships between waste package size and capacity, and the duration of surface decay storage needed to meet temperature limits for different disposal concepts. For the crystalline rock and clay/shale repository concepts, a waste package surface temperature limit of 100 deg. C was assumed to prevent changes in clay-based buffer material or clay-rich host rock. Surface decay storage of 50 to 100 years is needed for disposal of high-burnup LWR SNF in 4-PWR packages, or disposal of HLW glass from reprocessing LWR uranium oxide (UOX) fuel. High-level waste (HLW) from reprocessing of metal fuel used in a fast reactor could be disposed after decay storage of 50 years or less. For disposal in salt the rock thermal conductivity is significantly greater, and higher temperatures (200 deg. C) can be tolerated at the waste package surface. Decay storage of 10 years or less is needed for high-burnup LWR SNF in 4-PWR

  2. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    NASA Astrophysics Data System (ADS)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche

  3. Influence des melanges complexes organiques sur le sort des dioxines et furanes: Implications dans le developpement de facteurs de caracterisation en analyse du cycle de vie

    NASA Astrophysics Data System (ADS)

    Taing, Eric

    The environmental fate of dioxins and furans, or polychlorodibenzo-p-dioxins and -furans (PCDD/Fs), leaching from wood poles treated with pentachlorophenol (PCP) oil is modified by the presence of oil. Interactions between co-contaminants, which also exist for other pollutants within the mixtures, were shown in the specific context of risk analysis, but have never been taken into account for the generic context of life cycle assessment (LCA). This decision-making tool relies on characterization factors (CF) to estimate the potential impacts of an emitted amount of a pollutant in different impact categories such as aquatic ecotoxicity and human toxicity. For these two impact categories, CFs are calculated from a cause-effect chain that models the environmental fate, exposure and effects of the pollutant (represented by a matrix of fate FF, exposure XF and effect EF, respectively), meaning that a modification of PCDD/Fs fate induces a change in PCDD/Fs CFs. The research question is therefore as follows: In life cycle impact assessment (LCIA), to what extent would the potential impacts of PCDD/Fs on aquatic ecotoxicity and human toxicity change when taking into account the influence of a complex organic mixture on PCDD/Fs fate?. Thus, the main objective is to develop CFs of PCDD/Fs when their fate is influenced by PCP oil and compare them with the CFs of PCDD/Fs without oil for the aquatic ecotoxicity and human toxicity impact categories. A mathematic approach is established to determine the new environmental distribution of PCDD/Fs in the presence of oil and a new FF' matrix is calculated from this new distribution to obtain new CFs' integrating oil influence. FF' and CF' are then compared to FF and CF of PCDD/Fs without the oil. Finally, potential (eco)toxic impacts of the PCDD/F Canadian emissions are calculated with the new CFs' of PCDD/Fs in presence of oil. By only focusing on the results for an emission into air, freshwater and natural soil on a continental

  4. A novel concept of QUADRISO particles Part III : applications to the plutonium-thorium fuel cycle.

    SciTech Connect

    Talamo, A.

    2009-03-01

    In the present study, a plutonium-thorium fuel cycle is investigated including the {sup 233}U production and utilization. A prismatic thermal High Temperature Gas Reactor (HTGR) and the novel concept of quadruple isotropic (QUADRISO) coated particles, designed at the Argonne National Laboratory, have been used for the study. In absorbing QUADRISO particles, a burnable poison layer surrounds the central fuel kernel to flatten the reactivity curve as a function of time. At the beginning of life, the fuel in the QUADRISO particles is hidden from neutrons, since they get absorbed in the burnable poison before they reach the fuel kernel. Only when the burnable poison depletes, neutrons start streaming into the fuel kernel inducing fission reactions and compensating the fuel depletion of ordinary TRISO particles. In fertile QUADRISO particles, the absorber layer is replaced by natural thorium with the purpose of flattening the excess of reactivity by the thorium resonances and producing {sup 233}U. The above configuration has been compared with a configuration where fissile (neptunium-plutonium oxide from Light Water Reactors irradiated fuel) and fertile (natural thorium oxide) fuels are homogeneously mixed in the kernel of ordinary TRISO particles. For the {sup 233}U utilization, the core has been equipped with europium oxide absorbing QUADRISO particles.

  5. Les examens de francais dans le second cycle en Grande-Bretagne (French Examinations in the Second Cycle in Great Britain)

    ERIC Educational Resources Information Center

    Nott, David

    1978-01-01

    A description of the status of foreign language instruction and testing in the context of the changing state of education. The content of Second Cycle French programs, a critique of French examinations and some samples of tests which point to change are discussed. (Text is in French.) (AMH)

  6. Effect of the Four-Step Learning Cycle Model on Students' Understanding of Concepts Related to Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Madu, B. C.

    2012-01-01

    The study explored the efficacy of four-step (4-E) learning cycle approach on students understanding of concepts related to Simple Harmonic Motion (SHM). 124 students (63 for experimental group and 61 for control group) participated in the study. The students' views and ideas in simple Harmonic Achievement test were analyzed qualitatively. The…

  7. Facilitating Conceptual Change in Understanding State of Matter and Solubility Concepts by Using 5E Learning Cycle Model

    ERIC Educational Resources Information Center

    Ceylan, Eren; Geban, Omer

    2009-01-01

    The main purpose of the study was to compare the effectiveness of 5E learning cycle model based instruction and traditionally designed chemistry instruction on 10th grade students' understanding of state of matter and solubility concepts. In this study, 119 tenth grade students from chemistry courses instructed by same teacher from an Anatolian…

  8. Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

    NASA Technical Reports Server (NTRS)

    Six, L. D.; Ashe, T. L.; Dobler, F. X.; Elkins, R. T.

    1980-01-01

    Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

  9. Representing and constructing liquefaction cycle alternatives for FLNG FEED using system entity structure concepts

    NASA Astrophysics Data System (ADS)

    Ha, Sol; Lee, Kyu-Yeul

    2014-09-01

    To support the procedure for determining an optimal liquefaction cycle for FLNG FEED, an ontological modeling method which can automatically generate various alternative liquefaction cycles were carried out in this paper. General rules in combining equipment are extracted from existing onshore liquefaction cycles like C3MR and DMR cycle. A generic relational model which represents whole relations of the plant elements has all these rules, and it is expressed by using the system entity structure (SES), an ontological framework that hierarchically represents the elements of a system and their relationships. By using a process called pruning which reduces the SES to a candidate, various alternative relational models of the liquefaction cycles can be automatically generated. These alternatives were provided by XML-based formats, and they can be used for choosing an optimal liquefaction cycle on the basis of the assessments such as process simulation and reliability analysis

  10. The Vicious Cycle of Family Atmosphere, Interpersonal Self-concepts, and Paranoia in Schizophrenia—A Longitudinal Study

    PubMed Central

    Hesse, Klaus; Kriston, Levente; Mehl, Stephanie; Wittorf, Andreas; Wiedemann, Wolfgang; Wölwer, Wolfgang; Klingberg, Stefan

    2015-01-01

    Recent cognitive models of paranoid delusions highlight the role of self-concepts in the development and maintenance of paranoia. Evidence is growing that especially interpersonal self-concepts are relevant in the genesis of paranoia. In addition, negative interpersonal life-experiences are supposed to influence the course of paranoia. As dysfunctional family atmosphere corresponds with multiple distressing dyadic experiences, it could be a risk factor for the development and maintenance of paranoia. A total of 160 patients with a diagnosis of schizophrenia were assessed twice within 12 months. Standardized questionnaires and symptom rating scales were used to measure interpersonal self-concepts, perceived family atmosphere, and paranoia. Data were analyzed using longitudinal cross-lagged structural equation models. Perceived negative family atmosphere was associated with the development of more pronounced negative interpersonal self-concepts 12 months later. Moreover, paranoia was related to negative family atmosphere after 12 months as well. As tests revealed that reversed associations were not able to explain the data, we found evidence for a vicious cycle between paranoia, family atmosphere, and interpersonal self-concepts as suggested by theoretical/cognitive model of paranoid delusions. Results suggest that broader interventions for patients and their caretakers that aim at improving family atmosphere might also be able to improve negative self-concepts and paranoia. PMID:25925392

  11. The Vicious Cycle of Family Atmosphere, Interpersonal Self-concepts, and Paranoia in Schizophrenia-A Longitudinal Study.

    PubMed

    Hesse, Klaus; Kriston, Levente; Mehl, Stephanie; Wittorf, Andreas; Wiedemann, Wolfgang; Wölwer, Wolfgang; Klingberg, Stefan

    2015-11-01

    Recent cognitive models of paranoid delusions highlight the role of self-concepts in the development and maintenance of paranoia. Evidence is growing that especially interpersonal self-concepts are relevant in the genesis of paranoia. In addition, negative interpersonal life-experiences are supposed to influence the course of paranoia. As dysfunctional family atmosphere corresponds with multiple distressing dyadic experiences, it could be a risk factor for the development and maintenance of paranoia. A total of 160 patients with a diagnosis of schizophrenia were assessed twice within 12 months. Standardized questionnaires and symptom rating scales were used to measure interpersonal self-concepts, perceived family atmosphere, and paranoia. Data were analyzed using longitudinal cross-lagged structural equation models. Perceived negative family atmosphere was associated with the development of more pronounced negative interpersonal self-concepts 12 months later. Moreover, paranoia was related to negative family atmosphere after 12 months as well. As tests revealed that reversed associations were not able to explain the data, we found evidence for a vicious cycle between paranoia, family atmosphere, and interpersonal self-concepts as suggested by theoretical/cognitive model of paranoid delusions. Results suggest that broader interventions for patients and their caretakers that aim at improving family atmosphere might also be able to improve negative self-concepts and paranoia.

  12. Coculture with endothelial cells reduces the population of cycling LeX neural precursors but increases that of quiescent cells with a side population phenotype

    SciTech Connect

    Mathieu, Celine . E-mail: marc-andre.mouthon@cea.fr

    2006-04-01

    Neural stem cell proliferation and differentiation are regulated by external cues from their microenvironment. As endothelial cells are closely associated with neural stem cell in brain germinal zones, we investigated whether endothelial cells may interfere with neurogenesis. Neural precursor cells (NPC) from telencephalon of EGFP mouse embryos were cocultured in direct contact with endothelial cells. Endothelial cells did not modify the overall proliferation and apoptosis of neural cells, albeit they transiently delayed spontaneous apoptosis. These effects appeared to be specific to endothelial cells since a decrease in proliferation and a raise in apoptosis were observed in cocultures with fibroblasts. Endothelial cells stimulated the differentiation of NPC into astrocytes and into neurons, whereas they reduced differentiation into oligodendrocytes in comparison to adherent cultures on polyornithine. Determination of NPC clonogenicity and quantification of LeX expression, a marker for NPC, showed that endothelial cells decreased the number of cycling NPC. On the other hand, the presence of endothelial cells increased the number of neural cells having 'side population' phenotype, another marker reported on NPC, which we have shown to contain quiescent cells. Thus, we show that endothelial cells may regulate neurogenesis by acting at different level of NPC differentiation, proliferation and quiescence.

  13. Is the Rock Cycle an Outdated Idea, or a Unifying Concept?

    ERIC Educational Resources Information Center

    Eves, Robert Leo; Davis, Larry Eugene

    1988-01-01

    Discusses how rock-cycle diagrams can graphically illustrate the interrelationship between materials and processes in physical geology courses. Reviews nine contemporary physical geology textbooks with regard to their use of such diagrams. (TW)

  14. Development and proof-testing of advanced absorption refrigeration cycle concepts. Report on Phases 1 and 1A

    SciTech Connect

    Modahl, R.J.; Hayes, F.C.

    1992-03-01

    The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

  15. Contrôle non destructif par courants de Foucault : expérience et modélisation pour la conception et l'optimisation de capteurs

    NASA Astrophysics Data System (ADS)

    Bonnin, O.; Cahouet, J.; Giordano, P.

    1993-03-01

    more accurate comparison, for example on the crack depth, is difficult because of the uncertainty on the physical properties of the materials. Dans le cadre d'un projet industiel de conception et d'optimisation de capteurs pour la recherche de fissures par courants de Foucault sur les plate-formes de forage, on présente les études menées pour la modélisation du système. La simulation des phénomènes implique à priori une modélisation tridimensionnelle, certes précise, mais difficile et coûteuse. On cherche à en limiter le coût en combinant une modélisation bidimensionnelle en l'absence de défaut, et une modélisation tridimensionnelle locale en présence d'une fissure. Après avoir présenté le projet et l'étude expérimentale qui en découle, on décrit les techniques de modélisation qui ont été employées.

  16. A new concept for high-cycle-life LEO: Rechargeable MnO2-hydrogen

    NASA Technical Reports Server (NTRS)

    Appleby, A. John; Dhar, Y. J.; Murphy, O. J.; Srinivasan, Supramaniam

    1989-01-01

    The nickel-hydrogen secondary battery system is now the one of choice for use in GEO satellites. It offers superior energy density to that of nickel-cadmium, with a lifetime that is at least comparable in terms of both cycle life and overall operating life. While the number of deep cycles required for GEO use is small, LEO satellites with long lifetimes (5 to 10 years) will require secondary battery systems allowing 30,000 to 60,000 useful cycles which are characterized by an approximately 2C charge rate and C average discharge rate. Recent work has shown that birnessite MnO2 doped with bismuth oxide can be cycled at very high rates (6C) over a very large number of cycles (thousands) at depths-of-discharge in the 85 to 90 percent range, based on two electrons, which discharge at the same potential in a flat plateau. The potential is about 0.7 V vs. hydrogen, with a cut-off at 0.6 V. At first sight, this low voltage would seem to be a disadvantage, since the theoretical energy density will be low. However, it permits the use of lightweight materials that are immune from corrosion at the positive. The high utilization and low equivalent weight of the active material, together with the use of teflon-bonded graphite for current collection, result in very light positives, especially when these are compared with those in a derated nickel-hydrogen system. In addition, the weight of the pressure vessel falls somewhat, since the dead volume is lower. Calculations show that a total system will have 2.5 times the Ah capacity of a derated nickel-hydrogen LEO battery, so that the energy density, based on 1.2 V for nickel-hydrogen and 0.7 V for MnO2-hydrogen, will be 45 percent higher for comparable cycling performance.

  17. A new concept for high-cycle-life LEO: Rechargeable MnO2-hydrogen

    NASA Technical Reports Server (NTRS)

    Appleby, A. J.; Dhar, H. P.; Kim, Y. J.; Murphy, O. J.

    1989-01-01

    The nickel-hydrogen secondary battery system, developed in the early 1970s, has become the system of choice for geostationary earth orbit (GEO) applications. However, for low earth orbit (LEO) satellites with long expected lifetimes the nickel positive limits performance. This requires derating of the cell to achieve very long cycle life. A new system, rechargeable MnO2-Hydrogen, which does not require derating, is described here. For LEO applications, it promises to have longer cycle life, high rate capability, a higher effective energy density, and much lower self-discharge behavior than those of the nickel-hydrogen system.

  18. Cycle graph analysis for 3D roof structure modelling: Concepts and performance

    NASA Astrophysics Data System (ADS)

    Perera, Gamage Sanka Nirodha; Maas, Hans-Gerd

    2014-07-01

    The paper presents a cycle graph analysis approach to the automatic reconstruction of 3D roof models from airborne laser scanner data. The nature of convergences of topological relations of plane adjacencies, allowing for the reconstruction of roof corner geometries with preserved topology, can be derived from cycles in roof topology graphs. The topology between roof adjacencies is defined in terms of ridge-lines and step-edges. In the proposed method, the input point cloud is first segmented and roof topology is derived while extracting roof planes from identified non-terrain segments. Orientation and placement regularities are applied on weakly defined edges using a piecewise regularization approach prior to the reconstruction, which assists in preserving symmetries in building geometry. Roof corners are geometrically modelled using the shortest closed cycles and the outermost cycle derived from roof topology graph in which external target graphs are no longer required. Based on test results, we show that the proposed approach can handle complexities with nearly 90% of the detected roof faces reconstructed correctly. The approach allows complex height jumps and various types of building roofs to be firmly reconstructed without prior knowledge of primitive building types.

  19. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts.

    PubMed

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-08-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  20. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts

    PubMed Central

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-01-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  1. Evaluating new processes and concepts for energy and resource recovery from municipal wastewater with life cycle assessment.

    PubMed

    Remy, C; Boulestreau, M; Warneke, J; Jossa, P; Kabbe, C; Lesjean, B

    2016-01-01

    Energy and resource recovery from municipal wastewater is a pre-requisite for an efficient and sustainable water management in cities of the future. However, a sound evaluation of available processes and pathways is required to identify opportunities and short-comings of the different options and reveal synergies and potentials for optimization. For evaluating environmental impacts in a holistic view, the tool of life cycle assessment (LCA, ISO 14040/44) is suitable to characterize and quantify the direct and indirect effects of new processes and concepts. This paper gives an overview of four new processes and concepts for upgrading existing wastewater treatment plants towards energy positive and resource efficient wastewater treatment, based upon an evaluation of their environmental impacts with LCA using data from pilot and full-scale assessments of the considered processes.

  2. Concept Design for a High Temperature Helium Brayton Cycle with Interstage Heating and Cooling

    SciTech Connect

    Wright, Steven A.; Vernon, Milton E.; Pickard, Paul S.

    2013-12-01

    The primary metric for the viability of these next generation nuclear power plants will be the cost of generated electricity. One important component in achieving these objectives is the development of power conversion technologies that maximize the electrical power output of these advanced reactors for a given thermal power. More efficient power conversion systems can directly reduce the cost of nuclear generated electricity and therefore advanced power conversion cycle research is an important area of investigation for the Generation IV Program. Brayton cycles using inert or other gas working fluids, have the potential to take advantage of the higher outlet temperature range of Generation IV systems and allow substantial increases in nuclear power conversion efficiency, and potentially reductions in power conversion system capital costs compared to the steam Rankine cycle used in current light water reactors. For the Very High Temperature Reactor (VHTR), Helium Brayton cycles which can operate in the 900 to 950 C range have been the focus of power conversion research. Previous Generation IV studies examined several options for He Brayton cycles that could increase efficiency with acceptable capital cost implications. At these high outlet temperatures, Interstage Heating and Cooling (IHC) was shown to provide significant efficiency improvement (a few to 12%) but required increased system complexity and therefore had potential for increased costs. These scoping studies identified the potential for increased efficiency, but a more detailed analysis of the turbomachinery and heat exchanger sizes and costs was needed to determine whether this approach could be cost effective. The purpose of this study is to examine the turbomachinery and heat exchanger implications of interstage heating and cooling configurations. In general, this analysis illustrates that these engineering considerations introduce new constraints to the design of IHC systems that may require

  3. NASA / Pratt and Whitney Collaborative Partnership Research in Ultra High Bypass Cycle Propulsion Concepts

    NASA Technical Reports Server (NTRS)

    Hughes, Chris; Lord, Wed

    2008-01-01

    Current collaborative research with Pratt & Whitney on Ultra High Bypass Engine Cycle noise, performance and emissions improvements as part of the Subsonic Fixed Wing Project Ultra High Bypass Engine Partnership Element is discussed. The Subsonic Fixed Wing Project goals are reviewed, as well as their relative technology level compared to previous NASA noise program goals. Progress toward achieving the Subsonic Fixed Wing Project goals over the 2008 fiscal year by the UHB Partnership in this area of research are reviewed. The current research activity in Ultra High Bypass Engine Cycle technology, specifically the Pratt & Whitney Geared Turbofan, at NASA and Pratt & Whitney are discussed including the contributions each entity bring toward the research project, and technical plans and objectives. Pratt & Whitney Geared Turbofan current and future technology and business plans are also discussed, including the role the NASA SFW UHB partnership plays toward achieving those goals.

  4. Simulations and Measurements for a concept of powering CALICE-AHCAL at a train-cycled accelerator

    NASA Astrophysics Data System (ADS)

    Göttlicher, P.

    2013-01-01

    Improving calorimetry by usage of the particle-flow algorithm requires to record the details of the shower development. Therefore a high granularity analogue readout hadron calorimeter (AHCAL) with small sensors and with electronics handling the enormous amount of channels, ≈ 40 000/m3, is required. Homogeneity is maintained by avoiding cooling tubes in the active volume and only cooling at the service end. For this concept low power consumption per channel, 40 μW, is essential. Future linear e+e-- collider designs, ILC or CLIC, foresee duty cycles for the bunch delivery. At ILC bunch trains of 1 ms duration are followed by long breaks of 200 ms. Power cycling the front end electronics with the train structure can reduce power consumption by a factor 100. However for a full scale CALICE-AHCAL switched currents reach magnitudes of kilo-amperes. This paper describes the design chain from front end PCB's through to external power supplies. By simulations a concept is developed, in which effects of electromagnetic interferences are kept small and localized. The goal is to keep current loops small, to limit the switched current to the region near the switched consumer and to allow only small frequency currents to spread out further into the system. By that analogue performance can be kept high and parasitic couplings to the surrounding metal structures and other sub-detectors will be minimized. Measurements with existing prototypes support the validity of the simulations.

  5. Advanced steam power plant concepts with optimized life-cycle costs: A new approach for maximum customer benefit

    SciTech Connect

    Seiter, C.

    1998-07-01

    The use of coal power generation applications is currently enjoying a renaissance. New highly efficient and cost-effective plant concepts together with environmental protection technologies are the main factors in this development. In addition, coal is available on the world market at attractive prices and in many places it is more readily available than gas. At the economical leading edge, standard power plant concepts have been developed to meet the requirements of emerging power markets. These concepts incorporate the high technological state-of-the-art and are designed to achieve lowest life-cycle costs. Low capital cost, fuel costs and operating costs in combination with shortest lead times are the main assets that make these plants attractive especially for IPPs and Developers. Other aspects of these comprehensive concepts include turnkey construction and the willingness to participate in BOO/BOT projects. One of the various examples of such a concept, the 2 x 610-MW Paiton Private Power Project Phase II in Indonesia, is described in this paper. At the technological leading edge, Siemens has always made a major contribution and was pacemaker for new developments in steam power plant technology. Modern coal-fired steam power plants use computer-optimized process and plant design as well as advanced materials, and achieve efficiencies exceeding 45%. One excellent example of this high technology is the world's largest lignite-fired steam power plant Schwarze Pumpe in Germany, which is equipped with two 800 MW Siemens steam turbine generators with supercritical steam parameters. The world's largest 50-Hz single-shaft turbine generator with supercritical steam parameters rated at 1025 MW for the Niederaussem lignite-fired steam power plant in Germany is a further example of the sophisticated Siemens steam turbine technology and sets a new benchmark in this field.

  6. In-reactor testing of the closed cycle gas core reactor—the nuclear light bulb concept

    NASA Astrophysics Data System (ADS)

    Gauntt, Randall O.; Slutz, Stephen A.; Harms, Gary A.; Latham, Thomas S.; Roman, Ward C.; Rodgers, Richard J.

    1993-01-01

    The Nuclear Light Bulb (NLB) concept is an advanced closed cycle space propulsion rocket engine design that offers unprecidented performance characteristics in terms of specific impulse (≳1800 s) and thrust (≳445 kN). The NLB is a gas-core nuclear reactor making use of thermal radiation from a high temperature U-plasma core to heat the hydrogen propellant to very high temperatures (˜4000 K). The following paper describes analyses performed in support of the design of in-reactor tests that are planned to be performed in the Annular Core Research Reactor (ACRR) at Sandia National Laboratories in order to demonstrate the technical feasibility of this advanced concept. The tests will examine the stability of a hydrodynamically confined fissioning U-plasma under steady and transient conditions. Testing will also involve study of propellant heating by thermal radiation from the plasma and materials performance in the nuclear environment of the NLB. The analyses presented here include neutronic performance studies and U-plasma radiation heat-transport studies of small vortex-confined fissioning U-plasma experiments that are irradiated in the ACRR. These analyses indicate that high U-plasma temperatures (4000 to 9000 K) can be sustained in the ACRR for periods of time on the order of 5 to 20 s. These testing conditions are well suited to examine the stability and performance requirements necessary to demonstrate the feasibility of this concept.

  7. The impact of discovery learning on middle grade students' conceptions of the water cycle

    NASA Astrophysics Data System (ADS)

    Yoder, John D.

    This study examined the use of discovery learning in science and how it affects students' academic performance as well as their self-efficacy in science. It also used a diagnostic tool to identify students' misconceptions about processes in the water cycle and where the misconceptions originated. While the study showed that the treatment group had a statistically significant greater academic gain from the pre-test to the post- test than did the no-treatment comparison group, from a teachers view point the gain would not be enough to benefit a student's performance on high stakes tests. Because the study was able to identify eight common misconceptions, it suggests that the misconceptions that students possess are difficult to uproot even using teaching methods that have been proven successful.

  8. Concepts for Life Cycle Cost Control Required to Achieve Space Transportation Affordability and Sustainability

    NASA Technical Reports Server (NTRS)

    Rhodes, Russel E.; Zapata, Edgar; Levack, Daniel J. H.; Robinson, John W.; Donahue, Benjamin B.

    2009-01-01

    Cost control must be implemented through the establishment of requirements and controlled continually by managing to these requirements. Cost control of the non-recurring side of life cycle cost has traditionally been implemented in both commercial and government programs. The government uses the budget process to implement this control. The commercial approach is to use a similar process of allocating the non-recurring cost to major elements of the program. This type of control generally manages through a work breakdown structure (WBS) by defining the major elements of the program. If the cost control is to be applied across the entire program life cycle cost (LCC), the approach must be addressed very differently. A functional breakdown structure (FBS) is defined and recommended. Use of a FBS provides the visibifity to allow the choice of an integrated solution reducing the cost of providing many different elements of like function. The different functional solutions that drive the hardware logistics, quantity of documentation, operational labor, reliability and maintainability balance, and total integration of the entire system from DDT&E through the life of the program must be fully defined, compared, and final decisions made among these competing solutions. The major drivers of recurring cost have been identified and are presented and discussed. The LCC requirements must be established and flowed down to provide control of LCC. This LCC control will require a structured rigid process similar to the one traditionally used to control weight/performance for space transportation systems throughout the entire program. It has been demonstrated over the last 30 years that without a firm requirement and methodically structured cost control, it is unlikely that affordable and sustainable space transportation system LCC will be achieved.

  9. Conception et calibration d'un sonoreacteur pour l'oxydation de la cellulose par le systeme TEMPO/NaOCl/NaBr

    NASA Astrophysics Data System (ADS)

    Paquin, Michel

    Avec le contexte economique actuel dans le domaine des pates et papiers au Canada, l'industrie se doit de diversifier ses produits mis en marche. La fermeture de plus de 20 usines depuis 2005, une baisse du PIB de l'industrie de 1,4 milliard CAD entre 1999--2008, une baisse de la demande de 2,4 %, une diminution du prix de la pate de 20,9 % depuis juillet 2009. La delocalisation du secteur vers l'Asie et l'hemisphere sud sont autant de raisons pour laquelle l'industrie se doit d'etre a l'avant plan de nouvelle technologie a base de fibre de bois. Pour augmenter leur rentabilite, l'industrie se doit de diversifier ses produits dans d'autres secteurs que le simple fabricant de papier impression-ecriture. Sa diversification passe par l'elaboration de nouveaux papiers a valeur ajoutee (papier conducteur, papier bioactif, etc.), par l'utilisation de la biomasse forestiere pour la production d'energie, par l'utilisation de la biomasse forestiere pour l'elaboration d'une plateforme de chimie verte, par l'utilisation de la lignine pour le developpement de polymeres et par l'utilisation de la fibre cellulosique pour la fabrication de nanomateriaux. La fabrication de nanofibrille de cellulose peut devenir un des produits qui servira a diversifier la production des usines de pates et papiers. Les nanofibrilles de cellulose possedent des proprietes mecaniques et chimiques exceptionnelles. Les nanofibrilles de cellulose sont fabriquees a partir d'une oxydation selective de la pate kraft de feuillu avec le systeme TEMPO-NaOCl-NaBr. L'oxydation selective de l'alcool primaire en C6 du monomere de glucose sous forme de carboxylates engendre une modification chimique de la cellulose qui accroit l'hydrophilicite des fibrilles. Suite a cette oxydation, nous devons effectuer une desintegration mecanique de la fibre kraft de feuillu oxydee pour separer les fibrilles. Le processus d'oxydation de la fibre par le systeme TEMPO-NaOCl-NaBr et sa defibrillation par la suite engendre une

  10. A Burst Mode, Ultrahigh Temperature UF4 Vapor Core Reactor Rankine Cycle Space Power System Concept

    NASA Technical Reports Server (NTRS)

    Dugan, E. T.; Kahook, S. D.; Diaz, N. J.

    1996-01-01

    Static and dynamic neutronic analyses have been performed on an innovative burst mode (100's of MW output for a few thousand seconds) Ulvahigh Temperature Vapor Core Reactor (UTVR) space nuclear power system. The NVTR employs multiple, neutronically-coupled fissioning cores and operates on a direct, closed Rankine cycle using a disk Magnetohydrodynamic (MHD) generater for energy conversion. The UTVR includes two types of fissioning core regions: (1) the central Ultrahigh Temperature Vapor Core (UTVC) which contains a vapor mixture of highly enriched UF4 fuel and a metal fluoride working fluid and (2) the UF4 boiler column cores located in the BeO moderator/reflector region. The gaseous nature of the fuel the fact that the fuel is circulating, the multiple coupled fissioning cores, and the use of a two phase fissioning fuel lead to unique static and dynamic neutronic characteristics. Static neutronic analysis was conducted using two-dimensional S sub n, transport theory calculations and three-dimensional Monte Carlo transport theory calculations. Circulating-fuel, coupled-core point reactor kinetics equations were used for analyzing the dynamic behavior of the UTVR. In addition to including reactivity feedback phenomena associated with the individual fissioning cores, the effects of core-to-core neutronic and mass flow coupling between the UTVC and the surrounding boiler cores were also included in the dynamic model The dynamic analysis of the UTVR reveals the existence of some very effectlve inherent reactivity feedback effects that are capable of quickly stabilizing this system, within a few seconds, even when large positive reactivity insertions are imposed. If the UTVC vapor fuel density feedback is suppressed, the UTVR is still inherently stable because of the boiler core liquid-fuel volume feedback; in contrast, suppression of the vapor fuel density feedback in 'conventional" gas core cavity reactors causes them to become inherently unstable. Due to the

  11. Concepts and Strategies for Transparency Monitoring of Nuclear Materials at the Back End of the Fuel/Weapons Cycle

    SciTech Connect

    COSTIN, LAURENCE; DAVIES, PETER; PREGENZER, ARIAN L.

    1999-10-01

    Representatives of the Department of Energy, the national laboratories, the Waste Isolation Pilot Plant (WIPP), and others gathered to initiate the development of broad-based concepts and strategies for transparency monitoring of nuclear materials at the back end of the fuel/weapons cycle, including both geologic disposal and monitored retrievable storage. The workshop focused on two key questions: ''Why should we monitor?'' and ''What should we monitor?'' These questions were addressed by identifying the range of potential stakeholders, concerns that stakeholders may have, and the information needed to address those concerns. The group constructed a strategic framework for repository transparency implementation, organized around the issues of safety (both operational and environmental), diversion (assuring legitimate use and security), and viability (both political and economic). Potential concerns of the international community were recognized as the possibility of material diversion, the multinational impacts of potential radionuclide releases, and public and political perceptions of unsafe repositories. The workshop participants also identified potential roles that the WIPP may play as a monitoring technology development and demonstration test-bed facility. Concepts for WIPP'S potential test-bed role include serving as (1) an international monitoring technology and development testing facility, (2) an international demonstration facility, and (3) an education and technology exchange center on repository transparency technologies.

  12. Assessment of Possible Cycle Lengths for Fully-Ceramic Micro-Encapsulated Fuel-Based Light Water Reactor Concepts

    SciTech Connect

    R. Sonat Sen; Michael A. Pope; Abderrafi M. Ougouag; Kemal O. Pasamehmetoglu

    2012-04-01

    The tri-isotropic (TRISO) fuel developed for High Temperature reactors is known for its extraordinary fission product retention capabilities [1]. Recently, the possibility of extending the use of TRISO particle fuel to Light Water Reactor (LWR) technology, and perhaps other reactor concepts, has received significant attention [2]. The Deep Burn project [3] currently focuses on once-through burning of transuranic fissile and fissionable isotopes (TRU) in LWRs. The fuel form for this purpose is called Fully-Ceramic Micro-encapsulated (FCM) fuel, a concept that borrows the TRISO fuel particle design from high temperature reactor technology, but uses SiC as a matrix material rather than graphite. In addition, FCM fuel may also use a cladding made of a variety of possible material, again including SiC as an admissible choice. The FCM fuel used in the Deep Burn (DB) project showed promising results in terms of fission product retention at high burnup values and during high-temperature transients. In the case of DB applications, the fuel loading within a TRISO particle is constituted entirely of fissile or fissionable isotopes. Consequently, the fuel was shown to be capable of achieving reasonable burnup levels and cycle lengths, especially in the case of mixed cores (with coexisting DB and regular LWR UO2 fuels). In contrast, as shown below, the use of UO2-only FCM fuel in a LWR results in considerably shorter cycle length when compared to current-generation ordinary LWR designs. Indeed, the constraint of limited space availability for heavy metal loading within the TRISO particles of FCM fuel and the constraint of low (i.e., below 20 w/0) 235U enrichment combine to result in shorter cycle lengths compared to ordinary LWRs if typical LWR power densities are also assumed and if typical TRISO particle dimensions and UO2 kernels are specified. The primary focus of this summary is on using TRISO particles with up to 20 w/0 enriched uranium kernels loaded in Pressurized Water

  13. Fostering Third-Grade Students' Use of Scientific Models with the Water Cycle: Elementary teachers' conceptions and practices

    NASA Astrophysics Data System (ADS)

    Vo, Tina; Forbes, Cory T.; Zangori, Laura; Schwarz, Christina V.

    2015-10-01

    Elementary teachers play a crucial role in supporting and scaffolding students' model-based reasoning about natural phenomena, particularly complex systems such as the water cycle. However, little research exists to inform efforts in supporting elementary teachers' learning to foster model-centered, science learning environments. To address this need, we conducted an exploratory multiple-case study using qualitative research methods to investigate six 3rd-grade teachers' pedagogical reasoning and classroom instruction around modeling practices (construct, use, evaluate, and revise) and epistemic considerations of scientific modeling (generality/abstraction, evidence, mechanism, and audience). Study findings show that all teachers emphasized a subset of modeling practices-construction and use-and the epistemic consideration of generality/abstraction. There was observable consistency between teachers' articulated conceptions of scientific modeling and their classroom practices. Results also show a subset of the teachers more strongly emphasized additional epistemic considerations and, as a result, better supported students to use models as sense-making tools as well as representations. These findings provide important evidence for developing elementary teacher supports to scaffold students' engagement in scientific modeling.

  14. Conception d'un controleur actif pour le retard de la transition de l'ecoulement laminaire au turbulent sur une aile a geometrie du profil variable dans le tunnel a vent

    NASA Astrophysics Data System (ADS)

    Popov, Andrei Vladimir

    The aerospace industry is motivated to reduce fuel consumption in large transport aircraft, mainly through drag reduction. The main objective of the global project is the development of an active control system of wing airfoil geometry during flight in order to allow drag reduction. Drag reduction on a wing can be achieved through modifications in the laminar-to-turbulent flow transition point position, which should be situated as close as possible to the trailing edge of the airfoil wing. As the transition point plays a crucial part in this project, this work focuses on the control of its position on the airfoil, as an effect of controlling the deflection of a morphing wing airfoil equipped with a flexible skin. The paper presents the modeling and the experimental testing of the aerodynamic performance of a morphing wing, starting from the design concept phase all the way to the bench and wind tunnel tests phases. Several wind tunnel test runs for various Mach numbers and angles of attack were performed in the 6 x 9 ft2 wind tunnel at the Institute for Aerospace Research at the National Research Council Canada. A rectangular finite aspect ratio wing, having a morphing airfoil cross-section due to a flexible skin installed on the upper surface of the wing, was instrumented with Kulite transducers. The Mach number varied from 0.2 to 0.3 and the angle of attack between -1° and 2°. Unsteady pressure signals were recorded and analyzed and a thorough comparison, in terms of mean pressure coefficients and their standard deviations, was performed against theoretical predictions, using the XFoil computational fluid dynamics code. The acquired pressure data was analyzed through custom-made software created with Matlab/Simulink in order to detect the noise magnitude in the surface airflow and to localize the transition point position on the wing upper surface. This signal processing was necessary in order to detect the Tollmien-Schlichting waves responsible for triggering

  15. HTGR-GT closed-cycle gas turbine: a plant concept with inherent cogeneration (power plus heat production) capability

    SciTech Connect

    McDonald, C.F.

    1980-04-01

    The high-grade sensible heat rejection characteristic of the high-temperature gas-cooled reactor-gas turbine (HTGR-GT) plant is ideally suited to cogeneration. Cogeneration in this nuclear closed-cycle plant could include (1) bottoming Rankine cycle, (2) hot water or process steam production, (3) desalination, and (4) urban and industrial district heating. This paper discusses the HTGR-GT plant thermodynamic cycles, design features, and potential applications for the cogeneration operation modes. This paper concludes that the HTGR-GT plant, which can potentially approach a 50% overall efficiency in a combined cycle mode, can significantly aid national energy goals, particularly resource conservation.

  16. A Theory of Instruction: Using the Learning Cycle To Teach Science Concepts and Thinking Skills. NARST Monograph, Number One, 1989.

    ERIC Educational Resources Information Center

    Lawson, Anton E.; And Others

    This monograph describes the origins of the learning cycle, related research, and how future research might be conducted to further the understanding of theories of instruction. A wide range of information is synthesized, producing a coherent framework for better understanding the theory of the learning cycle. The monograph identifies various…

  17. A reappraisal of the terrestrial nitrogen cycle: what can we learn by extracting concepts from Gaia theory?

    PubMed

    Cresser, Malcolm S; Aitkenhead, Matthew J; Mian, Ishaq A

    2008-08-01

    Although soil scientists and most environmental scientists are acutely aware of the interactions between the cycling of carbon and nitrogen, for conceptual convenience when portraying the nitrogen cycle in text books the N cycle tends to be considered in isolation from its interactions with the cycling of other elements and water, usually as a snap shot at the current time; the origins of dinitrogen are rarely considered, for example. The authors suggest that Lovelock's Gaia hypothesis provides a useful and stimulating framework for consideration of the terrestrial nitrogen cycle. If it is used, it suggests that urbanization and management of sewage, and intensive animal rearing are probably bigger global issues than nitrogen deposition from fossil fuel combustion, and that plant evolution may be driven by the requirement of locally sustainable and near optimal soil mineral N supply dynamics. This may, in turn, be partially regulating global carbon and oxygen cycles. It is suggested that pollutant N deposition may disrupt this essential natural plant and terrestrial ecosystem evolutionary process, causing biodiversity change. Interactions between the Earth and other bodies in the solar system, and possibly beyond, also need to be considered in the context of the global N cycle over geological time scales. This is because of direct potential impacts on the nitrogen content of the atmosphere, potential long-term impacts of past boloid collisions on plate tectonics and thus on global N cycling via subduction and volcanic emissions, and indirect effects upon C, O and water cycling that all may impact upon the N cycle in the long term.

  18. High Speed Propulsion: Engine Design - Integration and Thermal Management (Propulsion a vitesse elevee : Conception du moteur - integration et gestion thermique)

    DTIC Science & Technology

    2010-09-01

    conception et optimisation des entrées d’air, moteurs à cycle combiné, intégration moteur- cellule , gestion thermique. Le fait que plusieurs programmes de...la conception de l’unité de propulsion et son intégration dans la cellule . En premier lieu, ont été traitées la physique, la conception et

  19. Enhancing Concept Comprehension in a Web-Based Course Using a Framework Integrating the Learning Cycle with Variation Theory

    ERIC Educational Resources Information Center

    Hsu, Chih-Chao; Wang, Tzone-I

    2014-01-01

    Concept comprehension is an important foundation for more complex thoughts. To enhance concept comprehension, teachers of traditional classrooms have been using instructional strategies and specific course designs, which have been proven effective. It initiates a hypothesis that integrating instructional strategies in the course designs of an…

  20. Army Manpower Cost System (AMCOS): Concept and Design for a Life Cycle Cost Model for Active Army Manpower

    DTIC Science & Technology

    1987-11-01

    Our view of life cycle cost analysis means that a life cycle cost model for manpower must not be, simply, an exercise in historical cost accounting...authorized levels of organization (ALO). Often, one of the more difficult problems in cost estimation exercises during the POM process is obtaining a rapid...certain types of models that have been suggested in the past. For example, the "Minimum Flow Model" of Mannle and Risser (1982), which provides the

  1. ASSESSMENT OF POSSIBLE CYCLE LENGTHS FOR FULLY-CERAMIC MICRO-ENCAPSULATED FUEL-BASED LIGHT WATER REACTOR CONCEPTS

    SciTech Connect

    R. Sonat Sen; Michael A. Pope; Abderrafi M. Ougouag; Kemal Pasamehmetoglu; Francesco Venneri

    2012-04-01

    The use of TRISO-particle-based dispersion fuel within SiC matrix and cladding materials has the potential to allow the design of extremely safe LWRs with failure-proof fuel. This paper examines the feasibility of LWR-like cycle length for such a low enriched uranium fuel with the imposed constraint of strictly retaining the original geometry of the fuel pins and assemblies. The motivation for retaining the original geometry is to provide the ability to incorporate the fuel 'as-is' into existing LWRs while retaining their thermal-hydraulic characteristics. The feasibility of using this fuel is assessed by looking at cycle lengths and fuel failure rates. Other considerations (e.g., safety parameters, etc.) were not considered at this stage of the study. The study includes the examination of different TRISO kernel diameters without changing the coating layer thicknesses. The study shows that a naive use of UO{sub 2} results in cycle lengths too short to be practical for existing LWR designs and operational demands. Increasing fissile inventory within the fuel compacts shows that acceptable cycle lengths can be achieved. In this study, starting with the recognized highest packing fraction practically achievable (44%), higher enrichment, larger fuel kernel sizes, and the use of higher density fuels have been evaluated. The models demonstrate cycle lengths comparable to those of ordinary LWRs. As expected, TRISO particles with extremely large kernels are shown to fail under all considered scenarios. In contrast, the designs that do not depart too drastically from those of the nominal NGNP HTR fuel TRISO particles are shown to perform satisfactorily and display a high rates of survival under all considered scenarios. Finally, it is recognized that relaxing the geometry constraint will result in satisfactory cycle lengths even using UO{sub 2}-loaded TRISO particles-based fuel with enrichment at or below 20 w/o.

  2. Fostering Third-Grade Students' Use of Scientific Models with the Water Cycle: Elementary Teachers' Conceptions and Practices

    ERIC Educational Resources Information Center

    Vo, Tina; Forbes, Cory T.; Zangori, Laura; Schwarz, Christina V.

    2015-01-01

    Elementary teachers play a crucial role in supporting and scaffolding students' model-based reasoning about natural phenomena, particularly complex systems such as the water cycle. However, little research exists to inform efforts in supporting elementary teachers' learning to foster model-centered, science learning environments. To address this…

  3. The Relationship Between the Learning Style Perceptual Preferences of Urban Fourth Grade Children and the Acquisition of Selected Physical Science Concepts Through Learning Cycle Instructional Methodology.

    NASA Astrophysics Data System (ADS)

    Adams, Kenneth Mark

    The purpose of this research was to investigate the relationship between the learning style perceptual preferences of fourth grade urban students and the attainment of selected physical science concepts for three simple machines as taught using learning cycle methodology. The sample included all fourth grade children from one urban elementary school (N = 91). The research design followed a quasi-experimental format with a single group, equivalent teacher demonstration and student investigation materials, and identical learning cycle instructional treatment. All subjects completed the Understanding Simple Machines Test (USMT) prior to instructional treatment, and at the conclusion of treatment to measure student concept attainment related to the pendulum, the lever and fulcrum, and the inclined plane. USMT pre and post-test scores, California Achievement Test (CAT-5) percentile scores, and Learning Style Inventory (LSI) standard scores for four perceptual elements for each subject were held in a double blind until completion of the USMT post-test. The hypothesis tested in this study was: Learning style perceptual preferences of fourth grade students as measured by the Dunn, Dunn, and Price Learning Style Inventory (LSI) are significant predictors of success in the acquisition of physical science concepts taught through use of the learning cycle. Analysis of pre and post USMT scores, 18.18 and 30.20 respectively, yielded a significant mean gain of +12.02. A controlled stepwise regression was employed to identify significant predictors of success on the USMT post-test from among USMT pre-test, four CAT-5 percentile scores, and four LSI perceptual standard scores. The CAT -5 Total Math and Total Reading accounted for 64.06% of the variance in the USMT post-test score. The only perceptual element to act as a significant predictor was the Kinesthetic standard score, accounting for 1.72% of the variance. The study revealed that learning cycle instruction does not appear

  4. Workshop Summary Proceedings Document: G7 Alliance on Resource Efficiency: U.S.-hosted Workshop on the Use of Life Cycle Concepts in Supply Chain Management to Achieve Resource Efficiency

    EPA Pesticide Factsheets

    This proceedings document summarizes prepared remarks, presentations and discussions from the G7 Alliance on Resource Efficiency: U.S.-hosted Workshop on the Use of Life Cycle Concepts in Supply Chain Management to Achieve Resource Efficiency.

  5. Reactor moderator, pressure vessel, and heat rejection system of an open-cycle gas core nuclear rocket concept

    NASA Technical Reports Server (NTRS)

    Taylor, M. F.; Whitmarsh, C. L., Jr.; Sirocky, P. J., Jr.; Iwanczyke, L. C.

    1973-01-01

    A preliminary design study of a conceptual 6000-megawatt open-cycle gas-core nuclear rocket engine system was made. The engine has a thrust of 196,600 newtons (44,200 lb) and a specific impulse of 4400 seconds. The nuclear fuel is uranium-235 and the propellant is hydrogen. Critical fuel mass was calculated for several reactor configurations. Major components of the reactor (reflector, pressure vessel, and waste heat rejection system) were considered conceptually and were sized.

  6. Mechanisms and Concepts Paving the Way towards a Complete Transport Cycle of Plant Vacuolar Sorting Receptors[W][OA

    PubMed Central

    De Marcos Lousa, Carine; Gershlick, David C.; Denecke, Jurgen

    2012-01-01

    Delivery of proteins to the lytic vacuole in plants is a complex cascade of selective interactions that specifically excludes residents of the endoplasmic reticulum and secreted proteins. Vacuolar transport must be highly efficient to avoid mistargeting of hydrolytic enzymes to locations where they could be harmful. While plant vacuolar sorting signals have been well described for two decades, it is only during the last 5 years that a critical mass of data was gathered that begins to reveal how vacuolar sorting receptors (VSRs) may complete a full transport cycle. Yet, the field is far from reaching a consensus regarding the organelles that could be involved in vacuolar sorting, their potential biogenesis, and the ultimate recycling of membranes and protein machinery that maintain this pathway. This review will highlight the important landmarks in our understanding of VSR function and compare recent transport models that have been proposed so that an emerging picture of plant vacuolar sorting mechanisms can be drawn. PMID:22570446

  7. Quantification of urban metabolism through coupling with the life cycle assessment framework: concept development and case study

    NASA Astrophysics Data System (ADS)

    Goldstein, Benjamin; Birkved, Morten; Quitzau, Maj-Britt; Hauschild, Michael

    2013-09-01

    Cities now consume resources and produce waste in amounts that are incommensurate with the populations they contain. Quantifying and benchmarking the environmental impacts of cities is essential if urbanization of the world’s growing population is to occur sustainably. Urban metabolism (UM) is a promising assessment form in that it provides the annual sum material and energy inputs, and the resultant emissions of the emergent infrastructural needs of a city’s sociotechnical subsystems. By fusing UM and life cycle assessment (UM-LCA) this study advances the ability to quantify environmental impacts of cities by modeling pressures embedded in the flows upstream (entering) and downstream (leaving) of the actual urban systems studied, and by introducing an advanced suite of indicators. Applied to five global cities, the developed UM-LCA model provided enhanced quantification of mass and energy flows through cities over earlier UM methods. The hybrid model approach also enabled the dominant sources of a city’s different environmental footprints to be identified, making UM-LCA a novel and potentially powerful tool for policy makers in developing and monitoring urban development policies. Combining outputs with socioeconomic data hinted at how these forces influenced the footprints of the case cities, with wealthier ones more associated with personal consumption related impacts and poorer ones more affected by local burdens from archaic infrastructure.

  8. Amelioration de la perfusion des organes vitaux par la valve d’impedance inspiratoire et le concept de pompe respiratoire: rationnel physiologique et application clinique (Improving Vital Organs Perfusion by the Respiratory Pump: Physiology and Clinical Use)

    DTIC Science & Technology

    2013-09-01

    Actuellement, la gestion des soins intensifs des patients avec un traumatisme cérébral et une hémorragie est basée sur le maintien d’une PPCe adéquate pour...fondée en partie sur une publication récente par le Dr Convertino [53]. Déclaration d’intérêts Les auteurs déclarent ne pas avoir de conflits

  9. Eco-efficience et analyse des couts du cycle de vie: Developpement d'un outil d'aide a la conception dans l'industrie aeronautique

    NASA Astrophysics Data System (ADS)

    Mami, Fares

    The aeronautical sector, responsible for about 3 % of the world emissions of greenhouse gases, predict a 70 % growth in 2025 and 300 % to 500 % in 2050 of its emissions compared to the level of 2005. The decision-makers must thus be supported in their choice of conception to integrate the environmental aspect into the decision-making. Our industrial partner in the aeronautical sector developed an expertise in Life Cycle Assessment (LCA) and seeks to integrate the costs and the environmental impacts in a systematic way into the ecodesign of products. Based on the literature review and the objectives of this research we propose a model of eco-efficiency, which integrates LCA with Life Cycle Costing (LCC). This model is consistent with defined cost cutting and environmental impacts reduction targets and allows a simple interpretation of the results while minimizing the efforts during data collection. The model is applied for 3D printing as an alternative production process in the manufacturing of an aircraft blocker door. 3D printing is a new technology of production working by addition of material and present interesting opportunities of cost cutting and environmental impacts, particularly in the aeronautical domain. The results showed that 3D printing, when associated with improvement in the topology of the part, allows an improvement both on costs and environmental impacts of the part life cycle. Nevertheless, the results are sensitive to the productivity of the 3D printing machine, in particular with costs when the productivity of the 3D printing is reduced. This eco-efficiency model presents several opportunities of improvement. A more elaborate definition of the objectives in reduction of environmental impacts would allow to direct the choices in design to considerations of eco-efficiency at a macro level. Moreover, the integration of the social dimension in the model constitutes an important stage to operationalize the stakes of environmental and social

  10. Le Figaro. Revised.

    ERIC Educational Resources Information Center

    Crawford, Linda

    These instructional materials are designed for students with some French reading skills and vocabulary in late beginning or early intermediate senior high school French. The objectives are to introduce students to a French newspaper, "Le Figaro," and develop reading skills for skimming, gathering specific information, and relying on cognates. The…

  11. Lighting innovations in concept cars

    NASA Astrophysics Data System (ADS)

    Berlitz, Stephan; Huhn, Wolfgang

    2005-02-01

    Concept cars have their own styling process. Because of the big media interest they give a big opportunity to bring newest technology with styling ideas to different fairgrounds. The LED technology in the concept cars Audi Pikes Peak, Nuvolari and Le Mans will be explained. Further outlook for the Audi LED strategy starting with LED Daytime Running Lamp will be given. The close work between styling and technical engineers results in those concept cars and further technical innovations based on LED technologies.

  12. Le Chatelier's principle in replicator dynamics

    NASA Astrophysics Data System (ADS)

    Allahverdyan, Armen E.; Galstyan, Aram

    2011-10-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nash equilibrium within the replicator dynamics. We show that the principle can be reformulated as a majorization relation. This defines a stability notion that generalizes the concept of evolutionary stability. We determine criteria for a Nash equilibrium to satisfy the Le Chatelier principle and relate them to mutualistic interactions (game-theoretical anticoordination) showing in which sense mutualistic replicators can be more stable than (say) competing ones. There are globally stable Nash equilibria, where the Le Chatelier principle is violated even locally: in contrast to the thermodynamic equilibrium a Nash equilibrium can amplify small perturbations, though both types of equilibria satisfy the detailed balance condition.

  13. Le Chatelier's principle in replicator dynamics.

    PubMed

    Allahverdyan, Armen E; Galstyan, Aram

    2011-10-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nash equilibrium within the replicator dynamics. We show that the principle can be reformulated as a majorization relation. This defines a stability notion that generalizes the concept of evolutionary stability. We determine criteria for a Nash equilibrium to satisfy the Le Chatelier principle and relate them to mutualistic interactions (game-theoretical anticoordination) showing in which sense mutualistic replicators can be more stable than (say) competing ones. There are globally stable Nash equilibria, where the Le Chatelier principle is violated even locally: in contrast to the thermodynamic equilibrium a Nash equilibrium can amplify small perturbations, though both types of equilibria satisfy the detailed balance condition.

  14. Le mouvement du pôle

    NASA Astrophysics Data System (ADS)

    Bizouard, Christian

    2012-03-01

    Les variations de la rotation terrestre. En conditionnant à la fois notre vie quotidienne, notre perception du ciel, et bon nombre de phénomènes géophysiques comme la formation des cyclones, la rotation de la Terre se trouve au croisement de plusieurs disciplines. Si le phenomena se faisait uniformément, le sujet serait vite discuté, mais c'est parce que la rotation terrestre varie, même imperceptiblement pour nos sens, dans sa vitesse angulaire comme dans la direction de son axe, qu'elle suscite un grand intérêt. D'abord pour des raisons pratiques : non seulement les aléas de la rotation terrestre modi_ent à la longue les pointés astrométriques à un instant donné de la journée mais in_uencent aussi les mesures opérées par les techniques spatiales ; en consequence l'exploitation de ces mesures, par exemple pour déterminer les orbites des satellites impliqués ou pratiquer le positionnement au sol, nécessite une connaissance précise de ces variations. Plus fondamentalement, elles traduisent les propriétés globales de la Terre comme les processus physiques qui s'y déroulent, si bien qu'en analysant les causes des fluctuations observées, on dispose d'un moyen de mieux connaître notre globe. La découverte progressive des fluctuations de la rotation de la Terre a une longue histoire. Sous l'angle des techniques d'observation, trois époques se pro-celle du pointé astrométrique à l'oeil nu, à l'aide d'instruments en bois ou métalliques (quart de cercle muraux par exemple). À partir du XVIIe siècle débute l'astrométrie télescopique dont les pointés sont complétés par des datations de plus en plus précises grâce à l'invention d'horloges régulées par balancier. Cette deuxième époque se termine vers 1960, avec l'avènement des techniques spatiales : les pointés astrométriques sont délaissés au profit de la mesure ultra-précise de durées ou de fréquences de signaux électromagnétiques, grâce à l'invention des horloges

  15. First proof of concept of sustainable metabolite production from high solids fermentation of lignocellulosic biomass using a bacterial co-culture and cycling flush system.

    PubMed

    Yao, Wanying; Nokes, Sue E

    2014-12-01

    To improve the lignocellulose conversion for ABE in high solids fermentation, this study explored the feasibility of cycling the process through the cellulolytic or/and solventogenic phases via intermittent flushing of the fermentation media. Five different flushing strategies (varying medium ingredients, inoculum supplement and cycling through phases) were investigated. Flushing regularly throughout the cellulolytic phase is necessary because re-incubation at 65 °C significantly improved glucose availability by at least 6-fold. The solvents accumulation was increased by 4-fold using corn stover (3-fold using miscanthus) over that produced by flushing only through the solventogenic phase. In addition, cycling process was simplified by re-incubating the flushed cellulolytic phase with no re-inoculation because the initial inoculum of Clostridiumthermocellum remained viable throughout sequential co-culture. This study served as the first proof of the cycling flush system applied in co-cultural SSC and the knowledge gained can be used to design a farm-scale flushing system.

  16. Regenerative Heater Optimization for Steam Turbo-Generation Cycles of Generation IV Nuclear Power Plants with a Comparison of Two Concepts for the Westinghouse International Reactor Innovative and Secure (IRIS)

    SciTech Connect

    Williams, W.C.

    2002-08-01

    The intent of this study is to discuss some of the many factors involved in the development of the design and layout of a steam turbo-generation unit as part of a modular Generation IV nuclear power plant. Of the many factors involved in the design and layout, this research will cover feed water system layout and optimization issues. The research is arranged in hopes that it can be generalized to any Generation IV system which uses a steam powered turbo-generation unit. The research is done using the ORCENT-II heat balance codes and the Salisbury methodology to be reviewed herein. The Salisbury methodology is used on an original cycle design by Famiani for the Westinghouse IRIS and the effects due to parameter variation are studied. The vital parameters of the Salisbury methodology are the incremental heater surface capital cost (S) in $/ft{sup 2}, the value of incremental power (I) in $/kW, and the overall heat transfer coefficient (U) in Btu/ft{sup 2}-degrees Fahrenheit-hr. Each is varied in order to determine the effects on the cycles overall heat rate, output, as well as, the heater surface areas. The effects of each are shown. Then the methodology is then used to compare the optimized original Famiani design consisting of seven regenerative feedwater heaters with an optimized new cycle concept, INRC8, containing four regenerative heaters. The results are shown. It can be seen that a trade between the complexity of the seven stage regenerative Famiani cycle and the simplicity of the INRC8 cycle can be made. It is desired that this methodology can be used to show the ability to evaluate modularity through the value of size a complexity of the system as well as the performance. It also shows the effectiveness of the Salisbury methodology in the optimization of regenerative cycles for such an evaluation.

  17. Current Concepts in Conception Control

    PubMed Central

    Ringrose, C. A. Douglas

    1963-01-01

    The progressive increase in world population has become a most urgent global problem in recent years. Man has, however, been interested in controlling his reproductivity at the family level for many centuries. Historical aspects of this saga are reviewed. The modern era of conception control was ushered in by Makepeace et al. in 1937 when ovulation inhibition by progesterone was demonstrated. Confirmation of this by Pincus and associates, and development of the potent oral progestational agents, the 19-norsteroids, have made efficient reliable contraception a reality. Experience with one of these agents (Ortho-Novum, 2 mg.) in 115 patients through 805 cycles is presented. Conception control was 100% effective at this dosage. Side effects were minimal. Only three of the women discontinued the tablets because of these effects. All but five in this group of 115 preferred the oral contraceptives to methods previously employed. PMID:13973987

  18. MODeLeR: A Virtual Constructivist Learning Environment and Methodology for Object-Oriented Design

    ERIC Educational Resources Information Center

    Coffey, John W.; Koonce, Robert

    2008-01-01

    This article contains a description of the organization and method of use of an active learning environment named MODeLeR, (Multimedia Object Design Learning Resource), a tool designed to facilitate the learning of concepts pertaining to object modeling with the Unified Modeling Language (UML). MODeLeR was created to provide an authentic,…

  19. Integral Fast Reactor concept

    SciTech Connect

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path.

  20. Streptococcus pneumoniae, le transformiste.

    PubMed

    Johnston, Calum; Campo, Nathalie; Bergé, Matthieu J; Polard, Patrice; Claverys, Jean-Pierre

    2014-03-01

    Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Natural genetic transformation, which was discovered in this species, involves internalization of exogenous single-stranded DNA and its incorporation into the chromosome. It allows acquisition of pathogenicity islands and antibiotic resistance and promotes vaccine escape via capsule switching. This opinion article discusses how recent advances regarding several facets of pneumococcal transformation support the view that the process has evolved to maximize plasticity potential in this species, making the pneumococcus le transformiste of the bacterial kingdom and providing an advantage in the constant struggle between this pathogen and its host.

  1. Cg/Stability Map for the Reference H Cycle 3 Supersonic Transport Concept Along the High Speed Research Baseline Mission Profile

    NASA Technical Reports Server (NTRS)

    Giesy, Daniel P.; Christhilf, David M.

    1999-01-01

    A comparison is made between the results of trimming a High Speed Civil Transport (HSCT) concept along a reference mission profile using two trim modes. One mode uses the stabilator. The other mode uses fore and aft placement of the center of gravity. A comparison is make of the throttle settings (cruise segments) or the total acceleration (ascent and descent segments) and of the drag coefficient. The comparative stability of trimming using the two modes is also assessed by comparing the stability margins and the placement of the lateral and longitudinal eigenvalues.

  2. LeRC in-house experimental research

    NASA Technical Reports Server (NTRS)

    Lyons, Valerie J.

    1992-01-01

    The topics covered include the following: LeRC in-house experimental research; combustion concepts; schedule for in-house experiments; lean premixed prevaporized combustion; comparisons of low NO(x) lean premixed/prevaporized data; rich burn/quick quench/lean burn (RQL); RQL combustion; fuel rich catalytic combustion; advanced diagnostics; and ceramic matrix liner test rig.

  3. A biopharmaceutical classification-based Right-First-Time formulation approach to reduce human pharmacokinetic variability and project cycle time from First-In-Human to clinical Proof-Of-Concept.

    PubMed

    Ku, M Sherry; Dulin, Wendy

    2012-01-01

    A Right-First-Time approach is described for developing bona fide formulations for First-In-Human (FIH) to Proof-Of-Concept (POC) studies to meet an overarching goal of reduced project cycle time from IND to NDA (as short as four years). Bona fide formulations are tailor-made according to the drug's biopharmaceutical properties including solubility, permeability and stability. Solubilization techniques are used extensively to reduce oral absorption variability for most compounds. Bona fide formulations contain all necessary functional excipients such as diluent, solubilizer, stabilizer, pH adjuster, disintegrant and lubricant so formulation changes are minimized to avoid significant PK bridging studies. Cycle time of FIH formulation development is aligned with IND-enabling toxicology studies, generally 4-6 months. Resources range from 0.5 full time equivalents (FTE) for a BCS-1 compound to 3 FTE for a BCS-4 compound with high drug delivery hurdles. We have achieved our goal by taking the same formulation from FIH to POC 90% of the time and maintaining the same formulation platform from POC to commercial manufacturing 80% of the time in the past eight years. This strategy enables cycle time reduction from 7 to 4 years for IND to NDA by overlapping clinical study phases and eliminating clinical downtime due to PK bridging studies.

  4. Design considerations for space radiators based on the liquid sheet (LSR) concept

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Chubb, Donald L.

    1991-01-01

    Concept development work on space heat rejection subsystems tailored to the requirements of various space power conversion systems is proceeding over a broad front of technologies at NASA LeRC. Included are orbital and planetary surface based radiator concepts utilizing pumped loops, a variety of heat pipe radiator concepts, and the innovative liquid sheet radiator (LSR). The basic feasibility of the LSR concept was investigated in prior work which generated preliminary information indicating the suitability of the LSR concept for space power systems requiring cycle reject heat to be radiated to the space sink at low-to-mid temperatures (300 to 400 K), with silicon oils used for the radiator working fluid. This study is directed at performing a comparative examination of LSR characteristics as they affect the basic design of low earth orbit solar dynamic power conversion systems. The power systems considered were based on the closed Brayton (CBC) and the Free Piston Stirling (FPS) cycles, each with a power output of 2 kWe and using previously tested silicone oil (Dow-Corning Me2) as the radiator working fluid. Conclusions indicate that, due to its ability for direct cold end cooling, an LSR based heat rejection subsystem is far more compatible with a Stirling space power system than with a CBC, which requires LSR coupling by means of an intermediate gas/liquid heat exchanger and adjustment of cycle operating conditions.

  5. Une nouvelle voie pour la conception des implants intervertébraux

    NASA Astrophysics Data System (ADS)

    Gradel, T.; Tabourot, L.; Arrieux, R.; Balland, P.

    2002-12-01

    L'objectif de notre travail est la conception d'une nouvelle génération d'implants intersomatiques qui s'adapte parfaitement à la géométrie des plateaux vertébraux en se déformant. Pour cela, nous avons utilisé une nouvelle démarche qui consiste à simuler entièrement le procédé de fabrication en l'occurrence l'emboutissage, Cette simulation, en concervant l'historique des sollicitations exercées sur le matériau lors de sa mise en œuvre permet de valider très précisément sa résistance mécanique en fin de cycle. Au cours de cette étude, nous avons mené en parallèle deux analyses dites “ coopératives ” : l'une fondée sur un modèle phénoménologique de type HILL et l'autre sur un modèle multi-échelles prenant en compte des phénomènes plus physiques afin d'acquérir une bonne connaissance du comportement du matériau lors de la déformation. C'est pour sa bonne résistance, sa biocompatibilité et ses propriétés radiologiques que nous avons choisi le T40 (titane pur) comme matériau.

  6. PFB coal fired combined cycle development program. Advanced hot gas cleanup concept evaluation (Task 4. 3). Volume B. Developmental cyclone evaluation

    SciTech Connect

    Not Available

    1980-02-01

    This report summarizes the results of cold flow model testing of a conventional reverse-flow cyclone containing several developmental features designed to improve its separative performance. The four advanced features evaluated were: Outlet Scroll Skimming - to remove particles from the high dust concentration region at the periphery of the outlet dust; Base Purge - to reduce reentrainment of dust from the disengagement hopper; Increased Outlet Duct Engagement - to reduce short-circuiting of the inlet dust into the outlet; and Vortex Shield - to stabilize the point of vortex attachment at the cyclone base and thus reduce base pickup. A schematic of the advanced cyclone, showing the various developmental features, is provided. The results of the cold flow experiments showed that substantial improvement (approximately 30% reduction in exhaust emission) could be obtained from outlet skimming or from increased engagement of the exhaust dust. Furthermore, the effects of these features are additive so that about 60% overall reduction in emissions could be achieved by incorporating both of these elements. On the other hand, the vortex shield and the base purge had little effect on the separative performance. Almost all of the experimental results exhibited strong electrostatic influence. At high flowrates, the separative performance of the cyclone decreased as the flowrate was reduced, as expected from cyclone theory. Although the improvements obtained with the developmental cyclone are significant, further improvements appear possible with the Air Shield cyclone and the Electrocyclone. Consequently, subsequent efforts under the CFCC program were focused on these concepts.

  7. Le syndrome d’alcoolisme foetal

    PubMed Central

    2002-01-01

    L’alcool est un tératogène physique et comportemental. Le syndrome d’alcoolisme foetal (SAF) est un trouble courant mais encore sous-diagnostiqué découlant de la consommation d’alcool par la mère pendant la grossesse. Bien qu’il puisse être prévenu, le SAF est également invalidant. Même si le SAF est présent dans tous les groupes socioéconomiques du Canada, sa prévalence est élevée dans certaines communautés inuites et des Premières nations du Canada. Le présent énoncé porte sur la prévention, le diagnostic, le dépistage précoce et la prise en charge du SAF par les professionnels de la santé. La prévention du SAF doit s’effectuer à deux échelons. La prévention primaire consiste à éliminer le SAF par une formation en classe ou dans la collectivité et à inciter les femmes à éviter de consommer de l’alcool avant la conception et pendant la grossesse. La prévention secondaire consiste à repérer les femmes qui boivent pendant leur grossesse et à réduire leur consommation. Le présent énoncé décrit plusieurs stratégies de dépistage, dont la stratégie T-ACE (tolérance-agacement, réduction, éveil). Les dispensateurs de soins devraient recommander l’abstinence dès la première visite prénatale. Un envoi rapide en consultation en vue de traiter l’alcoolisme est recommandé pour les femmes enceintes incapables d’arrêter de boire. Le présent énoncé décrit le diagnostic de SAF, de SAF partiel ou atypique, d’anomalies congénitales et de troubles neurodéveloppementaux reliés à l’alcool. En cas d’exposition à l’alcool in utero, un diagnostic de SAF devrait être envisagé en présence d’un retard de croissance courant ou antérieur, de certaines anomalies faciales touchant la lèvre supérieure et les yeux et d’anomalies neurodéveloppementales. Ces caractéristiques sont mieux quantifiées au moyen d’une méthode diagnostique à quatre chiffres. Des stratégies de dépistage précoce des

  8. Le matérialisme scientifique

    NASA Astrophysics Data System (ADS)

    Meunier, Jean-François

    2004-03-01

    De nos jours, il arrive quotidiennement aux grands hommes d'avoir à fréquenter d'ignorants mortels épris d'une conviction maladive que la science est la grande responsable de tous les maux du monde. Évidemment sans physique atomique, il n'y aurait pas eu d'Hiroshima et sans révolution industrielle, pas de pollution et etc. Cependant, ces accusations envers le progrès technique sont tout à fait injustes, irréfléchies et, j'irai même jusqu'à dire, irresponsables, puisque le calcul, i.e. la planification, même la plus élémentaire, est ce qui caractérise le mieux, pragmatiquement, la société humaine. À mon avis, les problèmes sociaux tireraient plutôt leur origine de sciences sociales irréalistes, qui, concrètment, inspireraient ou serviraient d'alibis à ceux qui détiennent véritablement le pouvoir. Dans cet article, je tenterai donc de démontrer la meilleure véracité et efficacité du matérialisme scientifique. Cette doctrine, dont Mario Bunge est le plus illustre représentant, s'appuy sur les résultats théoriques et expérimentaux des sciences factuelles ainsi que sur l'exactitude logique des mathématiques, utilisées ici comme langage universel de l'expression des idées. Cette conception philosophique qui s'inspire principalement du modèle des théories physiques, stipule que les réalités sociales sont, comme tout autre réalité, matérielles, mathématisables et représentables comme des systèmes en interaction. En fait, le modèle des physiciens ayant historiquement fait ses preuves en matière de testabilité et de cohérence interne est proposé d'être appliquer aux sciences sociales, aujourd'hui scindées des sciences dites pures sous l'inspiration des pseudo penseurs néo-kantiens, phénoménologiques et post-moderne. Cette nouvelle approche permettrait ainsi d'évoluer plus exactement vers une compréhension des bases sociales et biologiques du comportement humain afin de développer une éthique sans cesse plus r

  9. NEP facilities (LeRC)

    NASA Technical Reports Server (NTRS)

    Vetrone, Robert H.

    1993-01-01

    The topics are presented in viewgraph form and include the following: the Electric Propulsion Research Building (no. 16) the Electric Power Laboratory (BLDG. 301); the Tank 6 Vacuum Facility; and test facilities for electric propulsion and LeRC.

  10. Le bégaiement

    PubMed Central

    Perez, Hector R.; Stoeckle, James H.

    2016-01-01

    Résumé Objectif Fournir une mise à jour sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental. Qualité des données Une recherche d’études récentes ou non portant sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental a été effectuée dans les bases de données MEDLINE et Cochrane. La plupart des recommandations s’appuient sur des études de petite envergure, des données probantes de qualité limitée ou des consensus. Message principal Le bégaiement est un trouble d’élocution fréquent chez les personnes de tous âges, il altère la fluidité verbale normale et l’enchaînement du discours. Le bégaiement a été lié à des différences de l’anatomie, du fonctionnement et de la régulation dopaminergique du cerveau qui seraient de source génétique. Il importe de poser le diagnostic avec attention et de faire les recommandations qui conviennent chez les enfants, car de plus en plus, le consensus veut que l’intervention précoce par un traitement d’orthophonie soit cruciale chez les enfants bègues. Chez les adultes, le bégaiement est lié à une morbidité psychosociale substantielle, dont l’anxiété sociale et une piètre qualité de vie. Les traitements pharmacologiques ont soulevé l’intérêt depuis quelques années, mais les données cliniques sont limitées. Le traitement des enfants et des adultes repose sur l’orthophonie. Conclusion De plus en plus de recherches ont tenté de lever le voile sur la physiopathologie du bégaiement. La meilleure solution pour les enfants et les adultes bègues demeure la recommandation à un traitement d’orthophonie.

  11. Introduction to combined cycles

    NASA Astrophysics Data System (ADS)

    Moore, M. J.

    Ideas and concepts underlying the technology of combined cycles including the scientific principles involved and the reasons these cycles are in fashion at the present time, are presented. A cycle is a steady flow process for conversion of heat energy into work, in which a working medium passes through a range of states, returning to its original state. Cycles for power production are the steam cycle, which is a closed cycle, and the gas turbine, which represents an open cycle. Combined cycle thermodynamic parameters, are discussed. The general arrangement of the plant is outlined and important features of their component parts described. The scope for future development is discussed. It is concluded that for the next few years the natural gas fired combined cycle will be the main type of plant installed for electricity generation and cogeneration. Whilst gas turbines may not increase substantially in unit size, there remains scope for further increase in firing temperature with consequent increase in cycle performance. However the larger global reserves of coal are providing an incentive to the development of plant for clean coal combustion using the inherent advantage of the combined cycle to attain high efficiencies.

  12. Etude du Photochromisme et de la Photorefractivite dans le Poly

    NASA Astrophysics Data System (ADS)

    Ghailane, Fatima

    1995-11-01

    Nous avons etudie la possibilite d'utiliser un materiau organique, le poly(vinylcarbazole) comme milieu de stockage optique de masse en temps reel. Ce materiau dope aux photochromes presente un potentiel non negligeable pour l'holographie de volume en temps reel. Plusiers cycles, Ecriture-Lecture-Effacement, ont ete enregistres dans cette matrice polymerique avec une resolution assez elevee. Une etude a ete menee afin d'obtenir la valeur des parametres comme l'epaisseur du film et l'intensite d'ecriture pour un angle d'enregistrement theta_{ acute ecriture} donne qui permettent d'obtenir les meilleures efficacites diffractionelles tout en preservant ce milieu de tout effet de fatigue ou de degradation. Ce polymere devient photorefractif une fois melange avec un bon accepteur de charge, le trinitrofluorenone et un bon chromophore non-lineaire, le disperse orange 25. Nous avons etudie experimentalement la conductivite en obscurite et la photoconductivite de ce materiau. Des simulations numeriques ont ete realisees en se basant sur le modele de Poole-Frenkel. Nous avons aussi etudie l'implantation de faisceaux d'ions d'oxygene d'energie 200 keV pour inscrire dans le PVCz un guide d'onde plan a profil d'indice. Une etude ESCA complete cette partie afin de savoir les modifications induites par implementation ionique a l'interieur du film polymerique.

  13. Le pompage optique naturel dans le milieu astrophysique

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne lele de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses r

  14. Advanced Concepts in Closed-Cycle Lasers.

    DTIC Science & Technology

    1980-03-01

    Halide Vapors and Applications," IEEE J. Quant. Elec. QE-15, 579 (July 1979). 173 72. E. J. Schimutschek, J. E. Celto, and J. A. Trias, ’ Mercuric ...J. R. McDonald, S. P. McGlynn, C. H. Kendrow, J. L. Roebber, and K. Weiss, "Ultraviolet Absorption Spectra of Mercuric Halides ," J. Chem. Phys. 56...reption rate laser lifeime Urin otyarnit spar scor, Shonabortorpotiy zai phtexiation merur Air halide ih eonuia abrtre noveAL/annularo-eucnig

  15. Les hommes regardent le ciel.

    NASA Astrophysics Data System (ADS)

    Jaschek, C.

    Contents: 1. Le ciel nocturne. 2. Le mouvement du soleil. 3. La lune et ses mouvements. 4. L'orientation des bâtiments. 5. Les étoiles et les constellations. 6. Les planètes. 7. Les comètes, météores et météorites. 8. Les phénomènes météorologico-astronomiques. 9. Les éclipses. 10. Le temps et les calendriers. 11. Astres et destinée humaine - l'astrologie. 12. Les mythes de la création du monde. 13. Les mythes de la fin du monde. 14. Astronomie et société.

  16. Developing an Action Concept Inventory

    ERIC Educational Resources Information Center

    McGinness, Lachlan P.; Savage, C. M.

    2016-01-01

    We report on progress towards the development of an Action Concept Inventory (ACI), a test that measures student understanding of action principles in introductory mechanics and optics. The ACI also covers key concepts of many-paths quantum mechanics, from which classical action physics arises. We used a multistage iterative development cycle for…

  17. Le verifiche della relatività generale

    NASA Astrophysics Data System (ADS)

    Tempesti, Piero

    2005-10-01

    La relatività di Einstein. La relatività generale messa alla prova. Le tre verifiche classiche: L'avanzamento del perielio di Mercurio - La deflessione della luce - Il redshift gravitazionale. Le verifiche di seconda generazione: Il rallentamento della luce - L'effetto Nordtvedt - Le onde gravitazionali e la "pulsar binaria".

  18. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-12-01

    XMM à la recherche de la matière exotique; Ancienne étoile; Le Trou noir volant; Magnétar; Stardust et Annefrank; Le centre de la galaxie; Deux trous noirs dans la même galaxie; Eruption géante sur Io; Le Soleil;

  19. Science and the Learning Cycle.

    ERIC Educational Resources Information Center

    Barman, Charles R.; And Others

    1992-01-01

    The Learning Cycle as an instructional strategy in science consists of three phases: exploration, concept introduction, and concept application. The strategy's support of language development in students with deafness is noted, and three lessons are presented: force (primary level), physical properties of matter (older elementary), and properties…

  20. Teaching Teachers: The Learning Cycle.

    ERIC Educational Resources Information Center

    Barman, Charles R.; Kotar, Michael

    1989-01-01

    Explains a teaching strategy in which students engage in hands-on activities before being introduced to new terms or reading text material. Outlines the learning cycle phases: exploration, concept introduction, and concept application using example activities. Provides guidelines and checklist for modifying lessons into this format. (RT)

  1. Menstrual Cycle

    MedlinePlus

    ... receive Pregnancy email updates Enter email Submit The menstrual cycle Day 1 starts with the first day of ... drop around Day 25 . This signals the next menstrual cycle to begin. The egg will break apart and ...

  2. Le LHC, un tunnel cosmique

    ScienceCinema

    None

    2016-07-12

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

  3. Concept Mapping

    ERIC Educational Resources Information Center

    Technology & Learning, 2005

    2005-01-01

    Concept maps are graphical ways of working with ideas and presenting information. They reveal patterns and relationships and help students to clarify their thinking, and to process, organize and prioritize. Displaying information visually--in concept maps, word webs, or diagrams--stimulates creativity. Being able to think logically teaches…

  4. The Learning Cycle: A Reintroduction

    NASA Astrophysics Data System (ADS)

    Maier, Steven J.; Marek, Edmund A.

    2006-02-01

    The learning cycle is an inquiry approach to instruction that continues to demonstrate significant effectiveness in the classroom.1-3 Rooted in Piaget's theory of intellectual development, learning cycles provide a structured means for students to construct concepts from direct experiences with science phenomena. Learning cycles have been the subject of numerous articles in science practitioner periodicals as well as the focus of much research in science education journals.4 This paper reintroduces the learning cycle by giving a brief description, followed by an example suitable for a range of physics classrooms.

  5. Teaching the Rock Cycle with Ease.

    ERIC Educational Resources Information Center

    Bereki, Debra

    2000-01-01

    Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

  6. Does It Have a Life Cycle?

    ERIC Educational Resources Information Center

    Keeley, Page

    2010-01-01

    If life continues from generation to generation, then all plants and animals must go through a life cycle, even though it may be different from organism to organism. Is this what students have "learned," or do they have their own private conceptions about life cycles? The formative assessment probe "Does It Have a Life Cycle?" reveals some…

  7. LeFort I Osteotomy

    PubMed Central

    Buchanan, Edward P.; Hyman, Charles H.

    2013-01-01

    The LeFort I osteotomy is one of the most commonly used procedures to correct midface deformities. It allows for correction in three dimensions including advancement, retrusion, elongation, and shortening. It is indicated, often in conjunction with mandibular surgery, for class II and III malocclusion, facial asymmetry, obstructive sleep apnea, and maxillary atrophy. Before surgery, proper orthodontics and surgical planning should be undertaken to ensure adequate outcomes. Overall, the surgery is widely used due to its low complication profile and reliable long-term results. PMID:24872761

  8. INCOMMANDS TDP: Development of Decision Aid Implementation Guidance for the INCOMMANDS Human Factors Design and Evaluation Guide (Elaboration des Directives Relatives a la Mise en Oeuvre de l’Aide a la Decision Pour le Guide de Conception et d’evaluation Tenant Compte des Facteurs Humains - INCOMMANDS)

    DTIC Science & Technology

    2007-05-01

    professionnel de l’ergonomie afin de vérifier si les incertitudes quant aux conseils relatifs au système sont conformes aux lignes directrices) et...questionnaire, effectuées par un professionnel de l’ergonomie afin de déterminer si le système fait la promotion de niveaux de charge de travail...to automation). Three factors underpin cognition- based trust (i.e., perceived understandability, technical competence , and reliability [of the

  9. Tested Demonstrations: Thermodynamic Changes, Kinetics, Equilibrium, and LeChatelier's Principle.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1984-01-01

    Procedures for demonstrating thermodynamic changes, kinetics and reaction mechanisms, equilibrium, and LeChatelier's principle are presented. The only materials needed for these demonstrations are beakers, water, assorted wooden blocks of varying thickness, assorted rubber tubing, and a sponge. The concepts illustrated in each demonstration are…

  10. The Adverse Effects of Le Chatelier's Principle on Teacher Understanding of Chemical Equilibrium

    ERIC Educational Resources Information Center

    Cheung, Derek

    2009-01-01

    Although the scientific inadequacy of Le Chatelier's principle has long been documented in the literature, the principle is still treated as a central concept of chemical equilibrium by textbook writers and teachers in many countries. In the past, researchers' interest has focused on student misconceptions about chemical equilibrium and has…

  11. A Concept Map Knowledge Model of Intelligence Analysis

    DTIC Science & Technology

    2011-05-01

    Results: The CMap KM of intelligence analysis focuses on those aspects of the intelligence analysis process that affect human performance . The... performance humaine. Le modèle couvre une vingtaine de sujets différents, il répertorie et définit des douzaines de concepts relevant de l’analyse des...renseignements. Ce modèle a été élaboré grâce au logiciel CMapTools mis au point par l’Institute for Human and Machine Cognition, une entreprise située

  12. Cycle Analysis

    SciTech Connect

    Wright, Steven A.

    2012-03-20

    1. The Cycle Analysis code is an Microsoft Excel code that performs many different types of thermodynamic cycle analysis for power producing systems. The code will calculate the temperature and pressure and all other thermodynamic properties at the inlet and outlet of each component. The code also calculates the power that is produced, the efficiency, and the heat transported in the heater, gas chiller and recuperators. The code provides a schematic of the loop and provides the temperature and pressure at each location in the loop. The code also provides a T-S (temperature-entropy) diagram of the loop and often it provides an pressure enthalpy plot as well. 2. This version of the code concentrates on supercritical CO2 power cycles, but by simply changing the name of the working fluid many other types of fluids can be analyzed. The Cycle Analysis code provided here contains 18 different types of power cycles. Each cycle is contained in one worksheet or tab that the user can select. The user can change the yellow highlighted regions to perform different thermodynamic cycle analysis.

  13. Developing an action concept inventory

    NASA Astrophysics Data System (ADS)

    McGinness, Lachlan P.; Savage, C. M.

    2016-06-01

    We report on progress towards the development of an Action Concept Inventory (ACI), a test that measures student understanding of action principles in introductory mechanics and optics. The ACI also covers key concepts of many-paths quantum mechanics, from which classical action physics arises. We used a multistage iterative development cycle for incorporating expert and student feedback into successive revisions of the ACI. The student feedback, including think-aloud interviews, enabled us to identify their misconceptions about action physics.

  14. Cycling injuries.

    PubMed Central

    Cohen, G. C.

    1993-01-01

    Bicycle-related injuries have increased as cycling has become more popular. Most injuries to recreational riders are associated with overuse or improper fit of the bicycle. Injuries to racers often result from high speeds, which predispose riders to muscle strains, collisions, and falls. Cyclists contact bicycles at the pedals, seat, and handlebars. Each is associated with particular cycling injuries. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:8471908

  15. The Learning Cycle: A Basic Tool for Teachers, Too.

    ERIC Educational Resources Information Center

    Barman, Charles R.; And Others

    1993-01-01

    Learning cycle techniques (exploration, concept introduction, and concept application) are presented as an effective way to help students with hearing impairments to develop science concepts and process skills. A teacher inservice program developed at the University of Indiana to help teachers use learning cycle strategies for teaching science is…

  16. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2008-09-01

    Fragmentation et astéroïdes binaires; Astéroïde géocroiseur triple; Rosetta sort de son hibernation; Messenger; Transit lunaire vu par Deep Impact; Titan; Phobos; Phoenix; Einstein avait raison; Le ballet des taches rouges; Le poids des lentilles;

  17. Le syndrome d'apert

    PubMed Central

    Benmiloud, Sarra; Chaouki, Sana; Atmani, Samir; Hida, Moustapha

    2013-01-01

    Le syndrome d'Apert est une affection congénitale rare, caractérisée par une sténose cranio-faciale associée à une syndactylie des mains et des pieds. Sa prise en charge doit être précoce et multidisciplinaire. Sa gravité réside dans la coexistence de plusieurs malformations avec un risque d'hypertension intracrânienne chronique responsable d'une cécité et d'une débilité mentale. Les auteurs rapportent une nouvelle observation à travers laquelle ils illustrent les aspects cliniques et évolutifs ainsi que les difficultés thérapeutiques de cette affection. PMID:23565313

  18. Le Point sur... Astronomie IV

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  19. Intraday LeBaron effects

    PubMed Central

    Bianco, Simone; Corsi, Fulvio; Renò, Roberto

    2009-01-01

    We study the relation at intraday level between serial correlation and volatility of the Standard and Poor (S&P) 500 stock index futures returns. At daily and weekly levels, serial correlation and volatility forecasts have been found to be negatively correlated (LeBaron effect). After finding a significant attenuation of the original effect over time, we show that a similar but more pronounced effect holds by using intraday measures, by such as realized volatility and variance ratio. We also test the impact of unexpected volatility, defined as the part of volatility which cannot be forecasted, on the presence of intraday serial correlation in the time series by employing a model for realized volatility based on the heterogeneous market hypothesis. We find that intraday serial correlation is negatively correlated to volatility forecasts, whereas it is positively correlated to unexpected volatility.

  20. Concept Overview.

    ERIC Educational Resources Information Center

    Sandmann, B. J.

    1988-01-01

    Four teaching techniques were used to enhance conceptual learning and to increase student performance in a course in physical-chemical principles at the School of Pharmacy of the University of Missouri-Kansas City. One of the techniques, "concept overview," is described. (MLW)

  1. Vapor Compression Cycle Design Program (CYCLE_D)

    National Institute of Standards and Technology Data Gateway

    SRD 49 NIST Vapor Compression Cycle Design Program (CYCLE_D) (PC database for purchase)   The CYCLE_D database package simulates the vapor compression refrigeration cycles. It is fully compatible with REFPROP 9.0 and covers the 62 single-compound refrigerants . Fluids can be used in mixtures comprising up to five components.

  2. TQM: the essential concepts.

    PubMed

    Chambers, D W

    1998-01-01

    This is an introduction to the major concepts in total quality management, a loose collection of management approaches that focus on continuous improvement of processes, guided by routine data collection and adjustment of the processes. Customer focus and involvement of all members of an organization are also characteristics commonly found in TQM. The seventy-five-year history of the movement is sketched from its beginning in statistical work on quality assurance through the many improvements and redefinitions added by American and Japanese thinkers. Essential concepts covered include: control cycles, focus on the process rather than the defects, the GEAR model, importance of the customer, upstream quality, just-in-time, kaizen, and service quality.

  3. Que peut-on dire du prochain cycle solaire?

    NASA Astrophysics Data System (ADS)

    Simon, P.

    1997-01-01

    Avant me^me que soit complètement terminé le cycle des taches en cours, on peut déjà annoncer que le suivant aura des caractéristiques très proches de celui qui s'achève. En effet, depuis déjà trois à quatre ans, l'activité géomagnétique en cours appartient à la première phase de ce nouveau cycle.

  4. Menu Cycles.

    ERIC Educational Resources Information Center

    Clayton, Alfred; Almony, John

    The curriculum guide for commercial foods instruction is designed to aid the teacher in communicating the importance of menu cycles in commercial food production. It also provides information about the necessary steps in getting food from the raw form to the finished product, and then to the consumer. In addition to providing information on how to…

  5. Heat Cycle Reserch Experimental Program report, FY-84

    SciTech Connect

    Whitbeck, J.F.

    1984-09-01

    The Heat Cycle Research Facility (HCRF) is an experimental binary-cycle facility used to investigate different concepts and/or components for generating electrical power from a geothermal resource. This report briefly desc

  6. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2013-12-01

    ISON; (3200) Phaéton; Titan, lacs et hydrocarbures; Titan et le Soleil; Jets; z8_GND_5296; La nébuleuse de la Crevette; Planète isolée; Nébuleuse Toby Jug; Le pulsar du Crabe; Le bulbe de la Voie lactée; ALMA au grand complet; APEX, ArTéMiS; Sgr A*; Première détection de l’acétate de méthyle dans l’espace

  7. Developmental History of Liquid Oxygen Turbopumps for the LE-7 Engine

    NASA Astrophysics Data System (ADS)

    Kamijo, Kenjiro; Yamada, Hitoshi; Sakazume, Norio; Warashina, Shogo

    The first stage of the H-2 rocket used a 110-ton thrust liquid oxygen, liquid hydrogen, pump-fed engine, the LE-7. This engine required high-pressure and high-power liquid oxygen and liquid hydrogen turbopumps to achieve the two-stage combustion cycle in which the combustion pressure is around 13 MPa. Furthermore, it was very important to operate both turbopumps at higher rotational speeds to obtain a smaller, lighter-weight engine because the LE-7 had not low-speed, low-pressure pumps ahead of both the main pumps. The present paper shows the design, test results, and modifications that had been performed until a flight-type liquid oxygen turbopump for the LE-7 engine was completed. The liquid oxygen turbopump had been developed by the use of three models, that is, research, prototype, and flight models.

  8. Autoradiography and the Cell Cycle.

    ERIC Educational Resources Information Center

    Jones, C. Weldon

    1992-01-01

    Outlines the stages of a cell biology "pulse-chase" experiment in which the students apply autoradiography techniques to learn about the concept of the cell cycle. Includes (1) seed germination and plant growth; (2) radioactive labeling and fixation of root tips; (3) feulgen staining of root tips; (4) preparation of autoradiograms; and…

  9. Creative Writing and the Water Cycle.

    ERIC Educational Resources Information Center

    Young, Rich; Virmani, Jyotika; Kusek, Kristen M.

    2001-01-01

    Uses the story "The Life of a Drop of Water" to initiate a creative writing activity and teach about the water cycle. Attempts to stimulate students' understanding of a scientific concept by using their imaginations. (YDS)

  10. Jan Potocki et le "Gothic Novel"

    ERIC Educational Resources Information Center

    Finne, Jacques

    1970-01-01

    Establishes a parallel between the supernatural and fantastic qualities of Le Comte Jan Potocki's literary works, and the English gothic novels by comparing the elements of terror, mysterious atmosphere, and the supernatural beings involved. (DS)

  11. Technical Evaluation Report on the Guidance and Control Panel 53rd Symposium on Air Vehicle Mission Control and Management (La Gestion et le Controle des Missions des Vehicules Aeriens)

    DTIC Science & Technology

    1992-07-01

    d’importance dans le guidage et le pilotage des vehicules aeriens. Les developpements dans ce domaine representent des contributions d’une importance...d’un vehicule non-pilots. fonctionner en mode automatique. Les communications techniques ont examine les realisations et les tendances actuelles dans...le domaine de la gestion des missions des vehicules aeriens, presente !’tat de I’art et propos, des solutions technologiques pour la conception des

  12. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-06-01

    Deep Impact; Comète 73P/Schwassmann-Wachmann 3; L'anneau bleu d'Uranus; Triplet de neptunes; Triton; Dunes de Titan; Aréologie; Tache Rouge Junior; Obliquité des grosses planètes; Le jour de Saturne; Xéna; Un compagnon pour le Soleil; Galaxies satellites; Séisme sur une étoile à neutrons; Trou noir double; Hydrogène lointain

  13. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2005-03-01

    Trou noir glouton, Matière noire, Integral et le centre de notre Galaxie, Essaim de trous noirs, Carrousel autour de trous noirs, Érosion de trous noirs, Un quasar dans NGC 7319?, Distance de T Tauri, Chai non manquant, Des planètes autour d'une naine brune?, Titan, Une quatrième planète pour le pulsar PSR B1257+12, Smart 1, Aurores de Saturne

  14. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-02-01

    le errant; Pluton et Charon; Du côté d'Uranus !; Stardust; G29-38; La chasse aux planètes; Étoile polaire; Véga; Vers un interféromètre infrarouge à base kilométrique; Des pulsars extraordinaires; Trous noirs intermédiaires; Le trou noir central de la Galaxie; N44; Tornade spatiale

  15. La Vie Politique sous la Restauration a Travers ’Le Rouge et le Noir’ de Stendahl (The Political Life during the Restauration as Depicted in Le Rouge et le Noir by Stendahl)

    DTIC Science & Technology

    1989-01-01

    Valenod et Moirod, qul hissent le drapeau lib6ral uniquenient pour aznoIiorer leurs propres 20 conditions. Ils n’ont ni souci pour les paysans ni... propre benefice. Le lecteur est introduit a M. Valenod tres t~t dans le livre. 11 est le directeur du depot de mendicit6 A Verrlieres qui craint la visite... propres desse ins. Le groupe de vrais lib~t-aux stendhal lens comprend Fouqu6 qui est le bon ami de Julilen Sorel , le phi losophe Saint- Giraud. et

  16. Prometheus Hot Leg Piping Concept

    NASA Astrophysics Data System (ADS)

    Gribik, Anastasia M.; DiLorenzo, Peter A.

    2007-01-01

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  17. Promethus Hot Leg Piping Concept

    SciTech Connect

    AM Girbik; PA Dilorenzo

    2006-01-24

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  18. Prometheus Hot Leg Piping Concept

    SciTech Connect

    Gribik, Anastasia M.; DiLorenzo, Peter A.

    2007-01-30

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  19. Concept Mapping

    PubMed Central

    Brennan, Laura K.; Brownson, Ross C.; Kelly, Cheryl; Ivey, Melissa K.; Leviton, Laura C.

    2016-01-01

    Background From 2003 to 2008, 25 cross-sector, multidisciplinary community partnerships funded through the Active Living by Design (ALbD) national program designed, planned, and implemented policy and environmental changes, with complementary programs and promotions. This paper describes the use of concept-mapping methods to gain insights into promising active living intervention strategies based on the collective experience of community representatives implementing ALbD initiatives. Methods Using Concept Systems software, community representatives (n=43) anonymously generated actions and changes in their communities to support active living (183 original statements, 79 condensed statements). Next, respondents (n=26, from 23 partnerships) sorted the 79 statements into self-created categories, or active living intervention approaches. Respondents then rated statements based on their perceptions of the most important strategies for creating community changes (n=25, from 22 partnerships) and increasing community rates of physical activity (n=23, from 20 partnerships). Cluster analysis and multidimensional scaling were used to describe data patterns. Results ALbD community partnerships identified three active living intervention approaches with the greatest perceived importance to create community change and increase population levels of physical activity: changes to the built and natural environment, partnership and collaboration efforts, and land-use and transportation policies. The relative importance of intervention approaches varied according to subgroups of partnerships working with different populations. Conclusions Decision makers, practitioners, and community residents can incorporate what has been learned from the 25 community partnerships to prioritize active living policy, physical project, promotional, and programmatic strategies for work in different populations and settings. PMID:23079266

  20. Entrevue avec le Dr Charley Zeanah

    PubMed Central

    2013-01-01

    Le Dr Charles Zeanah est titulaire de la chaire de psychiatrie Mary K. Sellars-Polchow, professeur de pédiatrie clinique et vice-président de la pédopsychiatrie au département de psychiatrie et des sciences du comportement de la faculté de médecine de l’Université Tulane, à la Nouvelle-Orléans. Il est également directeur général de l’institut de la santé mentale des nourrissons et des jeunes enfants de Tulane. Il est récipiendaire de nombreux prix, notamment le prix de prévention Irving Phillips (AACAP), la mention élogieuse présidentielle pour sa recherche et son leadership exceptionnels en santé mentale des nourrissons (American Orthopsychiatric Association), le prix d’excellence clinique Sarah Haley Memorial (International Society for Traumatic Stress Studies), le prix de recherche en pédopsychiatrie Blanche F. Ittelson (APA), et le prix Serge Lebovici Award soulignant les contributions internationales à la santé mentale des nourrissons (World Association for Infant Mental Health). Le Dr Zeanah est fellow distingué de l’AACAP, fellow distingué de l’APA et membre du conseil d’administration de Zero to Three. Il est l’éditeur scientifique de Handbook of Infant Mental Health (3e édition) qui est considéré comme étant le manuel de pointe et la référence de base du domaine de la santé mentale des nourrissons.

  1. A New Concept of Synthetic Aperture Instrument for High Resolution Earth Observation from High Orbits

    DTIC Science & Technology

    2005-07-13

    ces composantes en adoptant une redécomposition des concepts d’interféromètres de type Fizeau ou Michelson . Concept qui autorise, en outre, de rendre le...considering monolithic concepts. It is necessary, to circumvent this problem, to consider a segmented instrument, turning it into a feasible concept...adopting a re-decomposition of the basic Michelson or Fizeau interferometer schemes. In addition to providing variable resolution power and field of

  2. [Some remarks on the theory of sets by Richard Dedekind and Stanisław Leśniewski].

    PubMed

    Obojska, Lidia

    2014-01-01

    Mereology, is a part-whole theory, also called the theory of collective sets. It was founded in 1916 by Stanisław Leśniewski and this is an alternative theory versus the classical set theory by Georg Cantor. These two theories are usually teamed up together as Leśniewski himself was referring to the concept of the set by Cantor and Cantor is considered the "main" ideologist of the set theory. However, when analyzing the original texts of various authors, it seems that the very concept of a collective set is closer to the idea of Richard Dedekind rather than that of Georg Cantor. It is known that Cantor borrowed some concepts on the notion of set from Dedekind, whose ideas were also known to Leśniewski, however, there is no study on this topic. This work is therefore an attempt to compare some set-theoretical concepts of both of these authors, i.e. S. Leśiewski and R. Dedekind and the presentation of their convergence.

  3. Concept Engineering: An Investigation Of TIME versus Market Orientation in Product Concept Development

    DTIC Science & Technology

    1993-06-01

    the concepts of: structured design process, dear customer requirements, and organizational commitment . 29 c V= a E1 (b3( E 3 IA 81P 2 04 co Uc 0...using and others not using Concept Engineering, led to the generation of a dynamic hypotheses regarding the impact of a relative emphasis on TIME vs...design, as illustrated in the figure below (NRC 1991; p.5). Life Cycle Cost Commitment 100 9 7 .... . S.... Life Cycle Phases 75 1. :Define use patterns

  4. Force cycles and force chains.

    PubMed

    Tordesillas, Antoinette; Walker, David M; Lin, Qun

    2010-01-01

    We examine the coevolution of N cycles and force chains as part of a broader study which is designed to quantitatively characterize the role of the laterally supporting contact network to the evolution of force chains. Here, we elucidate the rheological function of these coexisting structures, especially in the lead up to failure. In analogy to force chains, we introduce the concept of force cycles: N cycles whose contacts each bear above average force. We examine their evolution around force chains in a discrete element simulation of a dense granular material under quasistatic biaxial loading. Three-force cycles are shown to be stabilizing structures that inhibit relative particle rotations and provide strong lateral support to force chains. These exhibit distinct behavior from other cycles. Their population decreases rapidly during the initial stages of the strain-hardening regime-a trend that is suddenly interrupted and reversed upon commencement of force chain buckling prior to peak shear stress. Results suggest that the three-force cycles are called upon for reinforcements to ward off failure via shear banding. Ultimately though, the resistance to buckling proves futile; buckling wins under the combined effects of dilatation and increasing compressive load. The sudden increase in three-force cycles may thus be viewed as an indicator of imminent failure via shear bands.

  5. Family Development and the Family Life Cycle: An Empirical Evaluation.

    ERIC Educational Resources Information Center

    Spanier, Graham; And Others

    The concept of family life cycle has become increasingly prominent in the study of family development--the formation, maintenance, change, and dissolution of marriage and family relations. An evaluation of this concept is accomplished by examining the relationships between three possible stratification schemes: stage of the family life cycle,…

  6. Advanced Nuclear Fuel Cycle Options

    SciTech Connect

    Roald Wigeland; Temitope Taiwo; Michael Todosow; William Halsey; Jess Gehin

    2010-06-01

    A systematic evaluation has been conducted of the potential for advanced nuclear fuel cycle strategies and options to address the issues ascribed to the use of nuclear power. Issues included nuclear waste management, proliferation risk, safety, security, economics and affordability, and sustainability. The two basic strategies, once-through and recycle, and the range of possibilities within each strategy, are considered for all aspects of the fuel cycle including options for nuclear material irradiation, separations if needed, and disposal. Options range from incremental changes to today’s implementation to revolutionary concepts that would require the development of advanced nuclear technologies.

  7. Les Brulures Chimiques Par Le Laurier Rose

    PubMed Central

    Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.

    2010-01-01

    Summary Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose de gravité différente. Cela doit aboutir à une information élargie de la population, ainsi qu'une réglementation stricte de sa commercialisation. PMID:21991211

  8. Technium concept

    NASA Astrophysics Data System (ADS)

    Clement, Marc; Davies, Stephen

    2002-05-01

    Traditionally the economy of Wales has been based on the coal and steel industries. Recently, Wales has elected its own National Assembly and together with the Welsh Development Agency (WDA) and through a Regional Technology Plan, has prioritized the creation and development of a knowledge based economy. The culture of Wales has always placed emphasis on education and for a small nation, has a University sector with an excellent reputation for advanced research. The WDA and the University of Wales Swansea came together to establish Technium, which is an unique concept designed to bridge the gap between advanced University research and commercial exploitation. Technium was co-funded by the WDA and the European Regional Development Fund. The project is seen as the first phase of creating a network of sector specific Techniums across the country, all linked via state of the art telecomm-infrastructure to University centers of research excellence. This paper will describe two case studies, both in the Optics/Photonics field, of research centers being established in Technium by blue chip international companies. Those companies having located in Technium specifically because of the links to high quality university research. One company is Agilent Technologies Inc., USA) a global leader in Optoelectronic components. The second company, ICN Pharmaceuticals Inc, design and develop optical devices to be used in conjunction with pharmaceuticals for the treatment of a range of diseases. Working closely with the WDA and the University of Wales Swansea, these and other companies will pursue product development, sponsor postgraduate research and generate intellectual capital that will benefit the company, students and the region alike.

  9. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  10. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-09-01

    Jeunes étoiles et vieilles galaxies; Chiens de Chasse; Des images en partie belges; Détection chimique de planètes?; Amas cannibale; Le pulsar œil de bœuf; Supernova 2002 DJ; Centaurus A; Et de cent; Près du trou noir; Un cratère sous la Merdu Nord; Des astéroï des frôlent la Terre; Photons fatigués; Taches solaires; Un grand lac martien; Les naines brunes en infrarouge; Bourrelet équatorial; Fusion de trous noirs; Le hamburger de Gomez; Matière sombre; Non aux étoiles à quarks

  11. Le continu contre l'espace

    NASA Astrophysics Data System (ADS)

    Salanskis, Jean-Michel

    Disons pour conclure que, en tout état de cause, la façon de concevoir philosophiquement le conflit du continu et de l'espace que nous avons trouvée chez Hegel n'est pas homogène avec le style et les modalités de la pensée mathématique: 1) d'une part, le lien classique, le lien de référence entre continu et espace en mathématiques n'est pas que l'espace serait premier et privé de pensée, et le continu second, venant dissoudre l'espace en apportant la qualité, l'infini et la pensée, mais tout au contraire, il consiste en ce que l'espace est fondé sur l'abîme infinitaire du continu ; 2) d'autre part, l'éventuel divorce entre l'espace et le continu dans l'aire mathématique n'est pas celui d'une réflexivité purement conceptuelle du continu avec un positivisme géométrique, n'équivaut pas à une rupture disciplinaire ; il est plutôt le symptôme de la dérive d'une herméneutique à l'égard d'une autre, au sein d'un continent juridique commun définissant la discipline (la mathématique ensembliste), cette dérive pouvant, à la limite, induire une refonte de ce sol juridique, sans que jamais il soit question pour autant de nier l'unité des mathématiques, à comprendre ici comme l'unité ultime de responsabilité de la communauté mathématique à l'égard des trois questions Qu'est-ce que l'espace?”, “Qu'est-ce que le continu?” et “Qu'est-ce que l'infini?”.

  12. Advanced LMMHD space power generation concept

    NASA Astrophysics Data System (ADS)

    Ho, Vincent; Wong, Albert; Kim, Kilyoo; Dhir, Vijay

    Magnetohydrodynamic (MHD) power generation concept has been proposed and studied worldwide as one of the future power generation sources. An advanced one fluid two phase liquid metal (LM) MHD power generation concept was developed for space nuclear power generation design. The concept employs a nozzle to accelerate the liquid metal coolant to an acceptable velocity with Mach number greater than unity. Such nozzle and the MHD power generator replace the turbogenerator of a high temperature Rankine turboelectric cycle concept. As a result, the power generation system contains no movable parts. This provides high reliability, which is a very important factor in space application.

  13. Identification and Analysis of Student Conceptions Used To Solve Chemical Equilibrium Problems.

    ERIC Educational Resources Information Center

    Voska, Kirk W.; Heikkinen, Henry W.

    2000-01-01

    Identifies and quantifies the chemistry conceptions used by students when solving chemical equilibrium problems requiring application of LeChatelier's Principle, and explores the feasibility of designing a paper and pencil test to accomplish these purposes. Eleven prevalent incorrect student conceptions about chemical equilibrium were identified…

  14. Rocketdyne RBCC Concept Development

    NASA Technical Reports Server (NTRS)

    Ortwerth, P.; Ratekin, G.; Goldman, A.; Emanuel, M.; Brown, C.; Ketchum, A.; Horn, M.

    1997-01-01

    Rocketdyne is pursuing the conceptual design and development of a Rocket Based Combined Cycle (BBCC) engine for booster and SSTO, advanced reusable space transportation systems under the Advanced Reusable Transportation Technologies contract with NASA Marshall Space Flight Center. The Rocketdyne concept is a fixed geometry integrated rocket, ramjet, scramjet which is hydrogen fueled and uses hydrogen regenerative cooling. Vision vehicle integration studies have determined that scramjet operation to the range of Mach 10 to 12 has high payoff for low cost reusable space transportation. Rocketdyne is internally developing versions of the concept for other applications in high speed aircraft and missiles with hydrocarbon fuel systems. A subscale engine ground test program is underway for all modes of operation from takeoff to Mach 8. High altitude rocket tests will only be completed as part of the ground test program to validate high expansion ratio performance. A unique feature of the ground test series is the inclusion of dynamic trajectory simulation with real time Mach number, altitude, engine throttling, and RBCC mode changes in a specially modified freejet test facility at GASL. Preliminary cold flow air augmented rocket and all rocket test results have met program goals and have been used to integrate all modes of operation in a single combustor design with a fixed geometry inlet for design confirmation tests. A water cooled subscale engine is currently being fabricated for test during the early part of 1998.

  15. AXTAR: Mission Design Concept

    NASA Technical Reports Server (NTRS)

    Ray, Paul S.; Chakrabarty, Deepto; Wilson-Hodge, Colleen A.; Philips, Bernard F.; Remillard, Ronald A.; Levine, Alan M.; Wood, Kent S.; Wolff, Michael T.; Gwon, Chul S.; Strohmayer, Tod E.; Briggs, Michael S.; Capizzo, Peter; Fabisinski, Leo; Hopkins, Randall C.; Hornsby, Linda S.; Johnson, Les; Maples, C. Dauphne; Miernik, Janie H.; Thomas, Dan; DeGeronimo, Gianluigi

    2010-01-01

    The Advanced X-ray Timing Array (AXTAR) is a mission concept for X-ray timing of compact objects that combines very large collecting area, broadband spectral coverage, high time resolution, highly flexible scheduling, and an ability to respond promptly to time-critical targets of opportunity. It is optimized for sub-millisecond timing of bright Galactic X-ray sources in order to study phenomena at the natural time scales of neutron star surfaces and black hole event horizons, thus probing the physics of ultra-dense matter, strongly curved spacetimes, and intense magnetic fields. AXTAR s main instrument, the Large Area Timing Array (LATA) is a collimated instrument with 2 50 keV coverage and over 3 square meters effective area. The LATA is made up of an array of super-modules that house 2-mm thick silicon pixel detectors. AXTAR will provide a significant improvement in effective area (a factor of 7 at 4 keV and a factor of 36 at 30 keV) over the RXTE PCA. AXTAR will also carry a sensitive Sky Monitor (SM) that acts as a trigger for pointed observations of X-ray transients in addition to providing high duty cycle monitoring of the X-ray sky. We review the science goals and technical concept for AXTAR and present results from a preliminary mission design study

  16. Absorption Heat Pump Cycles

    NASA Astrophysics Data System (ADS)

    Kunugi, Yoshifumi; Kashiwagi, Takao

    Various advanced absorption cycles are studied, developed and invented. In this paper, their cycles are classified and arranged using the three categories: effect, stage and loop, then an outline of the cycles are explained on the Duehring diagram. Their cycles include high COP cycles for refrigerations and heat pumps, high temperature lift cycles for heat transformer, absorption-compression hybrid cycles and heat pump transformer cycle. The highest COPi is attained by the seven effect cycle. In addition, the cycles for low temperature are invented and explained. Furthermore the power generation • refrigeration cycles are illustrated.

  17. Radioisotope Power System Pool Concept

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  18. Open cycle thermoacoustics

    SciTech Connect

    Reid, Robert Stowers

    2000-01-01

    A new type of thermodynamic device combining a thermodynamic cycle with the externally applied steady flow of an open thermodynamic process is discussed and experimentally demonstrated. The gas flowing through this device can be heated or cooled in a series of semi-open cyclic steps. The combination of open and cyclic flows makes possible the elimination of some or all of the heat exchangers (with their associated irreversibility). Heat is directly exchanged with the process fluid as it flows through the device when operating as a refrigerator, producing a staging effect that tends to increase First Law thermodynamic efficiency. An open-flow thermoacoustic refrigerator was built to demonstrate this concept. Several approaches are presented that describe the physical characteristics of this device. Tests have been conducted on this refrigerator with good agreement with a proposed theory.

  19. Coal combined cycle system study. Volume I. Summary

    SciTech Connect

    Not Available

    1980-04-01

    The potential advantages for proceeding with demonstration of coal-fueled combined cycle power plants through retrofit of a few existing utility steam plants have been evaluated. Two combined cycle concepts were considered: Pressurized Fluidized Bed (PFB) combined cycle and gasification combined cycle. These concepts were compared with AFB steam plants, conventional steam plants with Flue Gas Desulfurization (FGD), and refueling such as with coal-oil mixtures. The ultimate targets are both new plants and conversion of existing plants. Combined cycle plants were found to be most competitive with conventional coal plants and offered lower air emissions and less adverse environmental impact. A demonstration is a necessary step toward commercialization.

  20. A Compositional Analysis of "-GUO" and "-LE."

    ERIC Educational Resources Information Center

    Mangione, L.; Li, Dingxuan

    1993-01-01

    Paper examines interaction of semantic contributions of aspect markers "-guo" and "-le"; negative adverbs "bu" and "mei"; and two classes of verbs. Proposed analysis systematically accounts for temporal orientation of members of several classes of sentences in terms of aspectual contributions made by two aspect markers, negative adverbs, verbs,…

  1. Technical Programme 1993 (Le Programme Technique, 1993)

    DTIC Science & Technology

    1992-09-01

    Symposium sur "Les Effets de la Propagation Atmospherique a travers des Obscurcissants Naturels et Artificiels sur le Rayonnement des Ondes Millimetriques...for Small Gas Turbines" Reunion du Panel et Symposium sur "Les Technologies pour les Petites Turbines a Gaz " 4-8 CANADA TIP Panel Meeting/Specialists

  2. Le Francais Courant: Part V, French.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    Instructional objectives of the Dade County Public Schools Quinmester Program in French for use with "Le Francais Courant: Part 5" focus on the development of mastery of the basic numbering system and other grammatical structures. Structures include the formation of the present tense of the irregular verbs…

  3. Le Chatelier--Right or Wrong?

    ERIC Educational Resources Information Center

    Helfferich, Friedrich G.

    1985-01-01

    Presents a class exercise designed to find out how well students understand the nature and consequences of the mass action law and Le Chatelier's principle as applied to chemical equilibria. The exercise relates to a practical situation and provides simple relations for maximizing equilibrium quantities not found in standard textbooks. (JN)

  4. Microscopic Description of Le Chatelier's Principle

    ERIC Educational Resources Information Center

    Novak, Igor

    2005-01-01

    A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…

  5. Le Chatelier's Principle, Temperature Effects, and Entropy.

    ERIC Educational Resources Information Center

    Campbell, J. Arthur

    1985-01-01

    One of the most useful methods of understanding chemical equilibria is provided by Le Chatelier's principle. The relationships between this principle, temperature, and entropy are discussed. Tables with thermodynamic data for some net reactions commonly used to illustrate the principle and for reactions involving gases are included. (JN)

  6. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2008-04-01

    Jets stellaires; Structure géante et matière noire; Un mini-système solaire; Arcs gravitationnels et images multiples; Choc frontal dans notre Galaxie; Avalanches martiennes; Du sable autour de KH 15D; Le cratère de Carancas; Smart-1;

  7. Hydrological cycle.

    PubMed

    Gonçalves, H C; Mercante, M A; Santos, E T

    2011-04-01

    The Pantanal hydrological cycle holds an important meaning in the Alto Paraguay Basin, comprising two areas with considerably diverse conditions regarding natural and water resources: the Plateau and the Plains. From the perspective of the ecosystem function, the hydrological flow in the relationship between plateau and plains is important for the creation of reproductive and feeding niches for the regional biodiversity. In general, river declivity in the plateau is 0.6 m/km while declivity on the plains varies from 0.1 to 0.3 m/km. The environment in the plains is characteristically seasonal and is home to an exuberant and abundant diversity of species, including some animals threatened with extinction. When the flat surface meets the plains there is a diminished water flow on the riverbeds and, during the rainy season the rivers overflow their banks, flooding the lowlands. Average annual precipitation in the Basin is 1,396 mm, ranging from 800 mm to 1,600 mm, and the heaviest rainfall occurs in the plateau region. The low drainage capacity of the rivers and lakes that shape the Pantanal, coupled with the climate in the region, produce very high evaporation: approximately 60% of all the waters coming from the plateau are lost through evaporation. The Alto Paraguay Basin, including the Pantanal, while boasting an abundant availability of water resources, also has some spots with water scarcity in some sub-basins, at different times of the year. Climate conditions alone are not enough to explain the differences observed in the Paraguay River regime and some of its tributaries. The complexity of the hydrologic regime of the Paraguay River is due to the low declivity of the lands that comprise the Mato Grosso plains and plateau (50 to 30 cm/km from east to west and 3 to 1.5 cm/km from north to south) as well as the area's dimension, which remains periodically flooded with a large volume of water.

  8. 30. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE, LE CLAIRE ...

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

    30. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE, LE CLAIRE BASE COMPOUND, LOOKING EAST - Mississippi River 9-Foot Channel, Lock & Dam No. 14, Upper Mississippi River, Le Claire, Scott County, IA

  9. 29. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE BUILDING, LE ...

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

    29. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE BUILDING, LE CLAIRE BASE COMPOUND, LOOKING WEST - Mississippi River 9-Foot Channel, Lock & Dam No. 14, Upper Mississippi River, Le Claire, Scott County, IA

  10. Students' and teachers' misapplication of le chatelier's principle: Implications for the teaching of chemical equilibrium

    NASA Astrophysics Data System (ADS)

    Quílez-Pardo, Juan; Solaz-Portolés, Joan Josep

    The aim of this article was to study the reasons, strategies, and procedures that both students and teachers use to solve some chemical equilibrium questions and problems. Inappropriate conceptions on teaching and a lack of knowledge regarding the limited usefulness of Le Chatelier's principle, with its vague and ambiguous formulation and textbook presentation, may be some of the sources of misconceptions about the prediction of the effect of changing conditions on chemical equilibrium. To diagnose misconceptions and their possible sources, a written test was developed and administered to 170 1st-year university chemistry students. A chemical equilibrium problem, relating to the students' test, was solved by 40 chemistry teachers. First, we ascertained that teacher's conceptions might influence the problem-solving strategies of the learner. Based on this first aspect, our discussion also concerns students' and teachers' misconceptions related to the Le Chatelier's principle. Misconceptions emerged through: (a) misapplication and misunderstanding of Le Chatelier's principle; (b) use of rote-learning recall and algorithmic procedures; (c) incorrect control of the variables involved; (d) limited use of the chemical equilibrium law; (e) a lack of mastery of chemical equilibrium principles and difficulty in transferring such principles to new situations. To avoid chemical equilibrium misconceptions, a specific pattern of conceptual and methodological change may be considered.Received: 16 November 1993; Revised: 21 September 1994;

  11. Advanced General Aviation Turbine Engine (GATE) concepts

    NASA Technical Reports Server (NTRS)

    Lays, E. J.; Murray, G. L.

    1979-01-01

    Concepts are discussed that project turbine engine cost savings through use of geometrically constrained components designed for low rotational speeds and low stress to permit manufacturing economies. Aerodynamic development of geometrically constrained components is recommended to maximize component efficiency. Conceptual engines, airplane applications, airplane performance, engine cost, and engine-related life cycle costs are presented. The powerplants proposed offer encouragement with respect to fuel efficiency and life cycle costs, and make possible remarkable airplane performance gains.

  12. Developing the concept of a geostationary platform. [for communication services

    NASA Technical Reports Server (NTRS)

    Carey, W. T.; Bowman, R. M.; Stone, G. R.

    1980-01-01

    A geostationary platform concept with a proliferation of low-cost earth stations is discussed. Candidate platform concepts, servicing, life, and Orbital Transfer Vehicle (OTV) options are considered. A Life Cycle Costing model is used to select the minimum cost concept meeting program criteria. It is concluded that the geostationary platform concept is a practical and economical approach to providing expanding communication services within the limitations imposed by the available frequency spectrum and orbital arc.

  13. SCIENCE BRIEF: ADVANCED CONCEPTS

    EPA Science Inventory

    Research on advanced concepts will evaluate and demonstrate the application of innovative infrastructure designs, management procedures and operational approaches. Advanced concepts go beyond simple asset management. The infusion of these advanced concepts into established wastew...

  14. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2003-09-01

    Système solaire poussiéreux; Combien d'étoiles dans le ciel?; Distance d'un pulsar; Planètes poussières et métaux; Un amateur belge bat les professionnels; Matière sombre; Supernova asymétrique; Anneau liégeois; Amas globulaires; Amas globulaires vagabonds; Baptême de satellites; Champ de gravité terrestre; Début de l'univers; XMM et Geminga; Carte neutrinos du ciel; Galaxies et trous noirs; Univers X; SMART-1: signal de départ pour l'aventure lunaire; Les saisons de Pluton; Planète dans M4; Rotation des pulsars; Un jumeau de Jupiter?; Le satellite ISO; Mars Express~:dernier clin d'oeil à la Terre; Waterworld: une réalité?

  15. Answering Key Fuel Cycle Questions

    SciTech Connect

    Piet, S.J.; Dixon, B.W.; Bennett, R.G.; Smith, J.D.; Hill, R.N.

    2004-10-03

    Given the range of fuel cycle goals and criteria, and the wide range of fuel cycle options, how can the set of options eventually be narrowed in a transparent and justifiable fashion? It is impractical to develop all options. We suggest an approach that starts by considering a range of goals for the Advanced Fuel Cycle Initiative (AFCI) and then posits seven questions, such as whether Cs and Sr isotopes should be separated from spent fuel and, if so, what should be done with them. For each question, we consider which of the goals may be relevant to eventually providing answers. The AFCI program has both ''outcome'' and ''process'' goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geologic repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are rea diness to proceed and adaptability and robustness in the face of uncertainties.

  16. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2013-06-01

    Une binaire remarquable; Collision de galaxies; La nébuleuse planétaire C1295; ALMA (suite); Couple massif; Astéroïdes lointains; L’eau de Jupiter; Occultation par Pluton; Super-Terres; Première image d’une planète massive autour d’une étoile double; Tempête au pôle de Saturne

  17. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-06-01

    Loi tchèque sur la pollution lumineuse; XTE J0929-314; Futurs amas de galaxies; Palomar 5; La météo des naines brunes; Trous noirs et galaxies elliptiques; Europe; 2MASS; Mars; Io; Matière sombre; Un objet très froid; Les oscillations stellaires; Un système lanétaire en formation; Binaire serrée; Satellites de Jupiter; Mars sous la loupe; Le Hubble nouveau

  18. Les Troubles Respiratoires Chez Le Brule

    PubMed Central

    Fassi Fihri, J.; Ezzoubi, M.; Boukind, E.H.

    2010-01-01

    Summary A travers une revue de la littérature, cet article se propose d'exposer les particularités des troubles respiratoires chez le brûlé. Ces troubles sont liés à un mécanisme direct, lorsque l'arbre respiratoire est lésé par le transfert d'énergie thermique du à la brûlure et/ou par un mécanisme indirect, lorsque la fonction respiratoire et ventilatoire du poumon est perturbée par les phénomènes loco-régionaux ou généraux du brûlé. Ces troubles respiratoires sont aggravés par l'inhalation des gaz contenus dans la fumée d'incendie. Le diagnostic de ces troubles est clinique et paraclinique. Il doit être précoce et continu. Les patients nécessitent de différents moyens thérapeutiques tels que l'oxygénothérapie, la libération des voies respiratoires, l'amélioration de la mécanique ventilatoire et de la fonction respiratoire, l'antibiothérapie ou la chirurgie des séquelles. Cette prise en charge doit nécessairement être multidisciplinaire. PMID:21991224

  19. Bipolar mood cycles and lunar tidal cycles.

    PubMed

    Wehr, T A

    2017-01-24

    In 17 patients with rapid cycling bipolar disorder, time-series analyses detected synchronies between mood cycles and three lunar cycles that modulate the amplitude of the moon's semi-diurnal gravimetric tides: the 14.8-day spring-neap cycle, the 13.7-day declination cycle and the 206-day cycle of perigee-syzygies ('supermoons'). The analyses also revealed shifts among 1:2, 1:3, 2:3 and other modes of coupling of mood cycles to the two bi-weekly lunar cycles. These shifts appear to be responses to the conflicting demands of the mood cycles' being entrained simultaneously to two different bi-weekly lunar cycles with slightly different periods. Measurements of circadian rhythms in body temperature suggest a biological mechanism through which transits of one of the moon's semi-diurnal gravimetric tides might have driven the patients' bipolar cycles, by periodically entraining the circadian pacemaker to its 24.84-h rhythm and altering the pacemaker's phase-relationship to sleep in a manner that is known to cause switches from depression to mania.Molecular Psychiatry advance online publication, 24 January 2017; doi:10.1038/mp.2016.263.

  20. Deriving fractional rate of degradation of logistic-exponential (LE) model to evaluate early in vitro fermentation.

    PubMed

    Wang, M; Sun, X Z; Tang, S X; Tan, Z L; Pacheco, D

    2013-06-01

    Water-soluble components of feedstuffs are mainly utilized during the early phase of microbial fermentation, which could be deemed an important determinant of gas production behavior in vitro. Many studies proposed that the fractional rate of degradation (FRD) estimated by fitting gas production curves to mathematical models might be used to characterize the early incubation for in vitro systems. In this study, the mathematical concept of FRD was developed on the basis of the Logistic-Exponential (LE) model, with initial gas volume being zero (LE0). The FRD of the LE0 model exhibits a continuous increase from initial (FRD 0) toward final asymptotic value (FRD F) with longer incubation time. The relationships between the FRD and gas production at incubation times 2, 4, 6, 8, 12 and 24 h were compared for four models, in addition to LE0, Generalization of the Mitscherlich (GM), c th order Michaelis-Menten (MM) and Exponential with a discrete LAG (EXPLAG). A total of 94 in vitro gas curves from four subsets with a wide range of feedstuffs from different laboratories and incubation periods were used for model testing. Results indicated that compared with the GM, MM and EXPLAG models, the FRD of LE0 model consistently had stronger correlations with gas production across the four subsets, especially at incubation times 2, 4, 6, 8 and 12 h. Thus, the LE0 model was deemed to provide a better representation of the early fermentation rates. Furthermore, the FRD 0 also exhibited strong correlations (P < 0.05) with gas production at early incubation times 2, 4, 6 and 8 h across all four subsets. In summary, the FRD of LE0 model provides an alternative to quantify the rate of early stage incubation, and its initial value could be an important starting parameter of rate.

  1. Screening analysis of solar thermochemical hydrogen concepts.

    SciTech Connect

    Diver, Richard B., Jr.; Kolb, Gregory J.

    2008-03-01

    A screening analysis was performed to identify concentrating solar power (CSP) concepts that produce hydrogen with the highest efficiency. Several CSP concepts were identified that have the potential to be much more efficient than today's low-temperature electrolysis technology. They combine a central receiver or dish with either a thermochemical cycle or high-temperature electrolyzer that operate at temperatures >600 C. The solar-to-hydrogen efficiencies of the best central receiver concepts exceed 20%, significantly better than the 14% value predicted for low-temperature electrolysis.

  2. Developpement d'un compresseur d'hydrogene base sur le cyclage thermique des hydrures metalliques

    NASA Astrophysics Data System (ADS)

    Laurencelle, Francois

    seul hydrure et en choisissant une temperature plus elevee pour la desorption (150°C). Un hydrure ABS (LaNi4.8Sn0.2) a ete soumis a 1000 cycles d'hydrogenation (article II). Sa structure et ses performances thermodynamiques et cinetiques ont ete mesurees avant et apres le cyclage. La capacite d'absorption a diminue de 0.02 H-pds%. Les particules d'hydrure ont diminue de taille sans changement apparent de leur structure cristalline. Le maintien des performances de cet hydrure apres cyclage en fait un excellent materiau pour les applications thermodynamiques. Nous avons effectue des simulations du reacteur d'hydrures utilise dans le compresseur. Celui-ci comporte une mousse d'aluminium qui est modelisee sous forme d'une cavite spherique (article III). Les performances modelisees sont comparables aux mesures obtenues et ce modele devient donc un outil de developpement pour de nouveaux reservoirs. D'apres cette etude, notre reacteur fonctionne de maniere optimale. Les performances du compresseur (chapitre 5) dependent des choix des temperatures et pressions a l'entree et a la sortie. La duree d'un cycle permettant l'absorption de la pleine capacite des materiaux est de ˜20 min mais en diminuant cette duree a <10 minutes un debit plus eleve 15-20 L/heure peut etre obtenu au detriment de l'efficacite. Le compresseur construit fonctionne bien mais il comporte des limitations clairement identifiees: pertes de chaleur dans la tuyauterie et les fixations des reacteurs. Le rejet thermique d'un electrolyseur est suffisant pour comprimer l'hydrogene qu'il produit d'un facteur 20:1 avec un compresseur a hydrure.

  3. Concepts in Change

    ERIC Educational Resources Information Center

    Rusanen, Anna-Mari; Poyhonen, Samuli

    2013-01-01

    In this article we focus on the concept of concept in conceptual change. We argue that (1) theories of higher learning must often employ two different notions of concept that should not be conflated: psychological and scientific concepts. The usages for these two notions are partly distinct and thus straightforward identification between them is…

  4. Concepts in Communication.

    ERIC Educational Resources Information Center

    Trent, Jimmie D.; And Others

    This book is a collection of ideas and information, gathered from various sources, which should aid college students in formulating their own methods of improving communication. The four main sections of the book are "Concepts of Communication,""Concepts of Source and Message,""Concepts of Communication Criticism," and "Concepts of Interpersonal…

  5. Environmental Education and Pupils' Conceptions of Matter.

    ERIC Educational Resources Information Center

    Hellden, Gustav

    1995-01-01

    Reports on a seven-year longitudinal study of pupils' (n=25) understanding of ecological processes with emphasis on how their conceptions of matter influence their understanding. Results indicate that initially students expected the plants cultivated in closed transparent boxes to die but later used a "cycle model" to explain how the…

  6. Exploring a Hydrological Concept through Children's Drawings.

    ERIC Educational Resources Information Center

    Dove, J. E.; Everett, L. A.; Preece, P. F. W.

    1999-01-01

    Examines children's (n=306) drawings of a river basin to determine their understanding of scientific concepts related to the water cycle. Presents exemplars of five levels of understanding and analysis of the drawings' orientation and content. Contains 24 references. (Author/WRM)

  7. Terminology gap in hydrological cycle

    NASA Astrophysics Data System (ADS)

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Water is central to life on Earth. People have been trying to understand how water moves in the hydrosphere throughout the human history. In the 9th century BC, the famous Greek poet Homer described the hydrological cycle in Iliad as "okeanos whose stream bends back in a circle" with a belief that rivers are ocean-fed from subterranean seas. Later, Aristotle (4th century BC) claimed that most of the water came from underground caverns in which air was transformed into water. It was only until 1674, French scientist Perrault developed the correct concept of the water cycle. In modern times, scientists are interested in understanding the individual processes of the hydrological cycle with a keen focus on runoff which supplies water to rivers, lakes, and oceans. Currently, the prevailing concepts on runoff processes include 'infiltration excess runoff' and 'saturation excess runoff'. However, there is no term to describe another major runoff due to the excess beyond the soil water holding capacity (i.e., the field capacity). We argue that a new term should be introduced to fill this gap, and it could be called 'holding excess runoff' which is compatible with the convention. This new term is significant in correcting a half-century misnomer where 'holding excess runoff' has been incorrectly named as 'saturation excess runoff', which was introduced by the Xinanjiang model in China in 1960s. Similar concept has been adopted in many well-known hydrological models such as PDM and HBV in which the saturation refers to the field capacity. The term 'holding excess runoff' resolves such a common confusion in the hydrological community.

  8. Le déficit immunitaire humoral: mieux le connaître pour mieux le prendre en charge

    PubMed Central

    El Bakkouri, Jalila; Aadam, Zahra; Ailal, Fatima; Alj, Hanane Salih; Bousfiha, Ahmed Aziz

    2014-01-01

    Les déficits immunitaires humoraux (DIH) sont des maladies hétérogènes allant des formes asymptomatiques rencontrés lors des déficits sélectifs en immunoglobulines A (IgA) et en sous-classes d'IgG aux formes graves des agammaglobulinémies congénitales. Les patients atteints de DIH présentent souvent des infections ORL ou des voies respiratoires récidivantes ou sévères. Ces patients peuvent présenter un certain nombre de complications non infectieuses, telles que des manifestations auto-immunes et des entéropathies, qui pourraient être le seul symptôme clinique révélateur. Les formes sévères des DIH sont facilement diagnostiquées grâce au dosage des IgG totaux, des IgA et des IgM. La thérapie substitutive par les immunoglobulines reste le traitement de choix chez ces patients. PMID:25489366

  9. Design analysis of the Einstein refrigeration cycle

    SciTech Connect

    Shelton, S.V.; Delano, A.; Schaefer, L.A.

    1999-07-01

    After developing the theory of relativity, Albert Einstein spent several years working with Leo Szilard on absorption refrigeration cycles. In 1930, they obtained a US patent for a unique single pressure absorption cycle. The single pressure eliminates the need for a solution pump. Their cycle has only recently been rediscovered. The cycle utilizes butane as its refrigerant, ammonia as a pressure equalizing fluid, and water as an absorbing fluid. This cycle is dramatically different in both concept and detail than the better-known ammonia-water-hydrogen cycle. In this study, thermodynamic and mixture property models of the Einstein cycle were created to gain insight into the cycle's operating characteristics and to calculate its performance. A conceptual demonstration model was built and successfully operated, showing for the first time the viability of the cycle. The model results found that the system pressure is an important design parameter, with the COP having an optimum when the system pressure is equal to the saturation pressure of the butane refrigerant. It was also found that for a given system pressure, there is a maximum condenser-absorber temperature and a minimum evaporator temperature.

  10. Sorption Refrigeration / Heat Pump Cycles

    NASA Astrophysics Data System (ADS)

    Saha, Bidyut Baran; Alam, K. C. Amanul; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    Over the past few decades there have been considerable efforts to use adsorption (solid/vapor) for cooling and heat pump applications, but intensified efforts were initiated only since the imposition of international restrictions on the production and use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Up to now, only the desiccant evaporative cooling system of the open type has achieved commercial use, predominantly in the United States. Closed-type adsorption refrigeration and heat pump systems are rarely seen in the market, or are still in the laboratory testing stage. Promising recent development have been made in Japan for the use of porous metal hydrides and composite adsorbents. In this paper, a short description of adsorption theories along with an overview of present status and future development trends of thermally powered adsorption refrigeration cycles are outlined putting emphasis on experimental achievements. This paper also addressed some advanced absorption cycles having relatively higher COP, and also summarizes fundamental concepts of GAX cycles and various GAX cycles developed for heat pump applications.

  11. The Solar Cycle.

    PubMed

    Hathaway, David H

    The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  12. The Solar Cycle

    NASA Astrophysics Data System (ADS)

    Hathaway, David H.

    2015-12-01

    The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fluxes, and radioisotopes in tree rings and ice cores. Individual solar cycles are characterized by their maxima and minima, cycle periods and amplitudes, cycle shape, the equatorward drift of the active latitudes, hemispheric asymmetries, and active longitudes. Cycle-to-cycle variability includes the Maunder Minimum, the Gleissberg Cycle, and the Gnevyshev-Ohl (even-odd) Rule. Short-term variability includes the 154-day periodicity, quasi-biennial variations, and double-peaked maxima. We conclude with an examination of prediction techniques for the solar cycle and a closer look at cycles 23 and 24.

  13. Supersonic variable-cycle engines

    NASA Technical Reports Server (NTRS)

    Willis, E. A.; Welliver, A. D.

    1976-01-01

    The evolution and current status of selected recent variable cycle engine (VCE) studies are reviewed, and how the results were influenced by airplane requirements is described. Promising VCE concepts are described, their designs are simplified and the potential benefits in terms of aircraft performance are identified. This includes range, noise, emissions, and the time and effort it may require to ensure technical readiness of sufficient depth to satisfy reasonable economic, performance, and environmental constraints. A brief overview of closely related, ongoing technology programs in acoustics and exhaust emissions is also presented. Realistic technology advancements in critical areas combined with well matched aircraft and selected VCE concepts can lead to significantly improved economic and environmental performance relative to first generation SST predictions.

  14. Le Chatelier's principle with multiple relaxation channels

    NASA Astrophysics Data System (ADS)

    Gilmore, R.; Levine, R. D.

    1986-05-01

    Le Chatelier's principle is discussed within the constrained variational approach to thermodynamics. The formulation is general enough to encompass systems not in thermal (or chemical) equilibrium. Particular attention is given to systems with multiple constraints which can be relaxed. The moderation of the initial perturbation increases as additional constraints are removed. This result is studied in particular when the (coupled) relaxation channels have widely different time scales. A series of inequalities is derived which describes the successive moderation as each successive relaxation channel opens up. These inequalities are interpreted within the metric-geometry representation of thermodynamics.

  15. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-04-01

    Cartographie d’une naine brune; 2006DP14; Anatomie d’un astéroïde; L’astéroïde P/2013 R3; Formation des planètes; Planètes Kepler; Bêta Pictoris; Cratère Mojave; Les astéroïdes de la ceinture principale; Planète X; Mercure et la gravitation; Gloire sur Vénus; Galaxies elliptiques massives; Cas A; SN 2014J et les supernovae Ia; Le Grand Nuage de Magellan; Nébuleuse d’Andromède; ESO 137-001

  16. Le synovialosarcome primitif de la verge

    PubMed Central

    Saadi, Ahmed; Bouzouita, Abderrazak; Kerkeni, Walid; Ayed, Haroun; Znaidi, Nadia Sabbegh; Ben Miled, Aicha; Messai, Taha; Cherif, Mohamed; Ben Slama, Riadh; Rammeh, Soumaya; Mnif, Najla; Maalej, Mongi; Derouiche, Amine; Chebil, Mohamed

    2017-01-01

    Résumé Le synovialosarcome représente un sous-type rare des sarcomes des tissus mous. Son apparition au niveau de la verge est exceptionnelle et seulement deux cas ont été rapportés dans la littérature auparavant. Nous rapportons un nouveau cas de synovialosarcome de la verge chez un jeune patient de 27 ans, en essayant par l’entremise d’une revue de la littérature de discuter des aspects radiologiques, histologiques, immunohistochimiques, thérapeutiques et pronostiques de cette tumeur exceptionnelle. PMID:28163814

  17. Growth Cycles of Brain and Mind.

    ERIC Educational Resources Information Center

    Rose, Samuel P.; Fischer, Kurt W.

    1998-01-01

    Whereas prior conceptions treated cognitive development as a sequence of stages, current research points to recurring growth cycles between birth and age 30. Each recurrence produces a new capacity for thinking and learning grounded in an expanded, reorganized neural network. Cognitive spurts are evident only under optimal support conditions.…

  18. A Preface to the Carnot Cycle.

    ERIC Educational Resources Information Center

    Goldstein, Martin

    1980-01-01

    Describes a new method for teaching the Second Law by way of the Carnot cycle. The two features of this method are that the isothermal process is considered first to establish some basic concepts, and then the nonisothermal cyclical process is introduced. (CS)

  19. Methanol decomposition bottoming cycle for IC engines

    NASA Technical Reports Server (NTRS)

    Purohit, G.; Houseman, J.

    1979-01-01

    This paper presents the concept of methanol decomposition using engine exhaust heat, and examines its potential for use in the operation of passenger cars, diesel trucks, and diesel-electric locomotives. Energy economy improvements of 10-20% are calculated over the representative driving cycles without a net loss in power. Some reductions in exhaust emissions are also projected.

  20. Different aspects of low-cycle fatigue

    NASA Technical Reports Server (NTRS)

    Bathias, C.

    1978-01-01

    The experimental and theoretical knowledge in this field is presented. The different relations which correlate the number of cyles to rupture with strain or strain-energy are given. The application of low-cycle fatigue concepts to the crack initiation and crack propagation are briefly studied.

  1. Variable-cycle engines for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Willis, E.

    1976-01-01

    Progress and the current status of the Variable Cycle Engine (VCE) study are reviewed with emphasis placed on the impact of technology advancements and design specifications. A large variety of VCE concepts are also examined.

  2. The Adverse Effects of Le Châtelier's Principle on Teacher Understanding of Chemical Equilibrium

    NASA Astrophysics Data System (ADS)

    Cheung, Derek

    2009-04-01

    Although the scientific inadequacy of Le Châtelier's principle has long been documented in the literature, the principle is still treated as a central concept of chemical equilibrium by textbook writers and teachers in many countries. In the past, researchers' interest has focused on student misconceptions about chemical equilibrium and has neglected teacher misconceptions. This study aimed to determine how Le Châtelier's principle adversely affects teachers' ability to solve chemical equilibrium problems. This area of research is critically important because teachers cannot help their students understand what they themselves do not understand. In this study, a misconception test was developed and administered to a sample of 33 secondary chemistry teachers in Hong Kong. The test consisted of three open-ended chemical equilibrium questions. Analysis of teacher responses revealed that most of the 33 teachers failed the test as they relied on Le Châtelier's principle rather than the equilibrium law to tackle the three chemical equilibrium problems. Teachers' misconceptions about chemical equilibrium were categorized. Implications of these findings for chemistry teacher education and selection of curriculum content for school chemistry are discussed.

  3. Lele de l’omalizumab dans le traitement de l’asthme allergique grave

    PubMed Central

    Chapman, Kenneth R; Cartier, André; Hébert, Jacques; McIvor, R Andrew; Schellenberg, R Robert

    2006-01-01

    CONTEXTE : Un nouveau traitement anti-immunoglobuline E (anti-IgE) contre l’asthme, l’omalizumab, a été approuvé au Canada. OBJECTIF : Passer en revue les données fondamentales et cliniques sur l’omalizumab et examiner lele possible de ce médicament dans la prise en charge de l’asthme au Canada. MÉTHODOLOGIE : Une recherche documentaire a été effectuée dans MEDLINE afin de repérer les études menées de 1960 à 2006 sur l’omalizumab. La recherche a également porté sur les résumés de réunions scientifiques récentes dans le domaine des maladies respiratoires et des allergies; par ailleurs, toute donnée non publiée a été demandée au fabricant. Après avoir revu et résumé les données, un comité mixte constitué de spécialistes des maladies respiratoires et des allergies a rédigé un ensemble de recommandations relatives à l’utilisation de l’omalizumab. RÉSULTATS : L’omalizumab est un anticorps monoclonal humanisé qui se lie au domaine C epsilon 3 de la molécule d’IgE pour former des complexes immuns solubles qui sont éliminés par le système réticulo-endothélial. L’administration d’injections sous-cutanées espacées de deux ou de quatre semaines à la dose recommandée entraîne une diminution rapide des taux d’IgE circulantes libres. Lors de deux essais cliniques de phase III menés auprès de 1 405 adultes et adolescents atteints d’asthme modéré à grave qui recevaient des doses moyennes stables de corticostéroïdes en inhalation (CSI), l’omalizumab a diminué les taux d’exacerbation par rapport au placebo et a été associé à une amélioration des symptômes ainsi qu’à une épargne plus importante des corticostéroïdes. Dans un essai mené auprès de 419 patients atteints d’asthme grave non maîtrisé malgré l’utilisation de doses élevées de CSI et de la prise concomitante d’agonistes bêta-2 à action prolongée, les exacerbations graves étaient de 50 % moins fréquentes chez

  4. Teach Life Science Concepts--with Picture Books.

    ERIC Educational Resources Information Center

    Texas Child Care, 2001

    2001-01-01

    Asserts that young children need help translating scientific theory into experiences that involve their senses. Provides age-appropriate, literature-based activities for exploring concepts and vocabulary in the areas of plant life cycles, animal life cycles, ocean ecology, and human growth development. Suggests specific works of children's…

  5. ADVANCED SULFUR CONTROL CONCEPTS

    SciTech Connect

    Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

    2003-01-01

    Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

  6. Behavioral Concepts in the Analysis of Chronic Pain Syndromes.

    ERIC Educational Resources Information Center

    Keefe, Francis J.; Gil, Karen M.

    1986-01-01

    Reviews behavioral and psychological concepts currently applied to the assessment and treatment of chronic pain syndromes, including operant conditioning and psychophysiologic concepts such as the stress-pain hypothesis, the pain-muscle spasm-pain cycle, and the neuromuscular pain model. Discusses relaxation and biofeedback training and concepts…

  7. Creative Concept Mapping.

    ERIC Educational Resources Information Center

    Brown, David S.

    2002-01-01

    Recommends the use of concept mapping in science teaching and proposes that it be presented as a creative activity. Includes a sample lesson plan of a potato stamp concept mapping activity for astronomy. (DDR)

  8. Subnational variations in conceptions.

    PubMed

    Wood, R

    1996-01-01

    Conception statistics are derived from information collected at the registration of live births, still births, and legal abortions. This article looks at how conception rates vary across England and Wales using the 1991 ONS area classification of DHAs (Population Trends 79). A comparison is made between age-specific conception rates for different area classification groups in 1993, and changes between 1983 and 1993 are examined. Correlations between certain social and economic factors and conception rates are also analysed.

  9. Conceptions of Ability.

    ERIC Educational Resources Information Center

    Jagacinski, Carolyn M.; Nicholls, John G.

    Two different conceptions of ability are proposed. The first conception of ability is more differentiated and generally employed by adults and older children. Here ability level is defined with reference to the performance of others assuming that optimum effort was employed. High ability means higher than others. The second conception of ability…

  10. Threshold Concepts in Biochemistry

    ERIC Educational Resources Information Center

    Loertscher, Jennifer

    2011-01-01

    Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…

  11. Concept Image Revisited

    ERIC Educational Resources Information Center

    Bingolbali, Erhan; Monaghan, John

    2008-01-01

    Concept image and concept definition is an important construct in mathematics education. Its use, however, has been limited to cognitive studies. This article revisits concept image in the context of research on undergraduate students' understanding of the derivative which regards the context of learning as paramount. The literature, mainly on…

  12. THE EPA'S EMERGING FOCUS ON LIFE CYCLE ASSESSMENT

    EPA Science Inventory

    EPA has been actively engaged in LCA research since 1990 to help advance the methodology and application of life cycle thinking in decision making. Across the Agency consideration of the life cycle concept is increasing in the development of policies and programs. A major force i...

  13. The Potassium-Argon Laser Experiment (KArLE): Design Concepts

    NASA Technical Reports Server (NTRS)

    Cho, Y.; Cohen, B. A.

    2017-01-01

    The absolute ages of geologic events are fundamental information for understanding the timing and duration of surface processes on planetary bodies. Absolute ages can place a planet's history in the context of the solar system evolution. For example, "when was Mars warm and wet?" is one of the key questions of planetary science. If Mars was warm and wet until 3.7 billion years ago, for instance, it suggests that Mars was still warm and wet when life appeared on Earth. Mars history has been discussed so far based on crater chronology, but the current constraints for Martian chronology models come from the cratering history of the Moon [1]. Moreover, the lunar chronology model itself is fraught with uncertainty because our understanding of lunar chronology is constrained only in a few time periods and itself needs further investigation relating crater-counting ages to absolute ages [2]. Although sample return missions would provide highly accurate radiometric ages of returned samples, they are very expensive and technically challenging. In situ geochronology is highly valuable because they would have larger number of mission opportunities and the capability of iterative measurements for multiple rocks from multiple geologic units. The capability of flight instruments to perform in situ dating is required in the NASA Planetary Science Decadal Survey and the NASA Technology Roadmap. Beagle 2 is the only mission launched to date with the explicit aim to perform in situ potassium-argon (K-Ar) dating [3], but it did not happen because of the communication failure to the spacecraft. The first in situ K-Ar dating on Mars, using SAM and APXS measurements on the Cumberland mudstone [4], yielded an age of 4.21 +/- 0.35 Ga and validated the idea of K-Ar dating on other planets. However, the Curiosity method is not purposebuilt for dating and requires many assumptions that degrade its accuracy. To obtain more accurate and meaningful ages, multiple groups are developing dedicated in situ dating instruments [5-8].

  14. Second Language Acquisition of the Chinese Particle "Le."

    ERIC Educational Resources Information Center

    Wen, Xiaohong

    1995-01-01

    This study investigated 14 English speakers' interlanguage constructions using the Chinese perfective aspect and the sentence-final modal particle. The results show that although the surface forms of the perfective aspect "-le" and the sentence-final "le" are identical, they are learned differently, with the perfective aspect…

  15. Insights: Simple Models for Teaching Equilibrium and Le Chatelier's Principle.

    ERIC Educational Resources Information Center

    Russell, Joan M.

    1988-01-01

    Presents three models that have been effective for teaching chemical equilibrium and Le Chatelier's principle: (1) the liquid transfer model, (2) the fish model, and (3) the teeter-totter model. Explains each model and its relation to Le Chatelier's principle. (MVL)

  16. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-11-01

    Glace et éclairs; Astéroïdes; Pluton; Avatars et avanie d'une petite planète (Xena, Eris); Nuage d'éthane sur Titan; Lacs de Titan; La NASA scrute Mars; Les express Mars et Venus; Cydonia, le visage sur Mars; Transit d'Ariel; Lune; Gonflée, la planète; Terres, terres!; Une planète extrasolaire aurait abrité de l'eau liquide; Des planètes au centre de la Voie Lactée; Anatomie d'un disque protoplanétaire; CHRX73 et pseudo-planète; Systèmes étranges; Premières galaxies; Voie Lactée; Neutrinos; RCW 86

  17. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2009-10-01

    Dunes de Titan; Lac Ontario; Titan; Anneaux de Saturne; Jupiter; Mars; Rotation de Saturne; Valles Marineris; Méthane martien; Epsilon Aurigae; Glycine cométaire; HD 87643; Pluton; Bételgeuse; Site astronomique; Andromède cannibale; Attaque de trou noir; BD+44 493; Formation d'étoiles; Gaz manquant; LIGO; M87; Naine blanche; Galaxie satellite; Galaxies naines sphéroïdales; Galaxies trapues; Cygnus X-1; L'avenir de la Voie Lactée; Naphtaline cosmique; Premiers trous noirs; Coup de foudre; Effet de serre; Glace lunaire; Impacts et extinctions; Exoplanètes rétrogrades; Kepler; Planète chaude; Collision planétaire; Disques dans le vent; Exoplanètes; Formation des planètes; Taches et transits

  18. HIV Life Cycle

    MedlinePlus

    HIV Overview The HIV Life Cycle (Last updated 9/13/2016; last reviewed 9/8/2016) Key Points HIV gradually destroys the immune ... life cycle. What is the connection between the HIV life cycle and HIV medicines? Antiretroviral therapy (ART) ...

  19. Developing mathematical practices through reflection cycles

    NASA Astrophysics Data System (ADS)

    Reinholz, Daniel L.

    2016-09-01

    This paper focuses on reflection in learning mathematical practices. While there is a long history of research on reflection in mathematics, it has focused primarily on the development of conceptual understanding. Building on notion of learning as participation in social practices, this paper broadens the theory of reflection in mathematics learning. To do so, it introduces the concept of reflection cycles. Each cycle begins with prospective reflection, which guides one's actions during an experience, and ends with retrospective reflection, which consolidates the experience and informs the next reflection cycle. Using reflection cycles as an organizing framework, this paper synthesizes the literature on reflective practices at a variety of levels: (1) metacognition, (2) self-assessment, (3) noticing, and (4) lifelong learning. These practices represent a spectrum of reflection, ranging from the micro level (1) to macro level (4).

  20. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2009-12-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  1. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert

    2007-04-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 26 cost modules—24 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, and high-level waste.

  2. Advanced Fuel Cycle Cost Basis

    SciTech Connect

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2008-03-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  3. Le contrôle des infections au cabinet du pédiatre

    PubMed Central

    2008-01-01

    RÉSUMÉ La transmission des infections au cabinet du pédiatre est de plus en plus préoccupante. Le présent document expose les voies de transmission des infections et les principes sous-jacents aux mesures actuelles pour contrôler les infections. Pour prévenir les infections, il faut bien concevoir le cabinet et adopter des politiques administratives et de triage convenables, de même que des pratiques de base pour les soins de tous les patients (p. ex., hygiène des mains, port de gants, de masques, de lunettes de protection et d’une blouse d’hôpital pour des interventions précises; nettoyage, désinfection et stérilisation convenables des surfaces et du matériel, y compris les jouets, et techniques d’asepsie en cas d’interventions effractives) et des précautions additionnelles en cas d’infections précises. Le personnel doit avoir reçu les vaccins pertinents, et les personnes infectées doivent respecter les politiques de restriction au travail.

  4. Understanding of Earth and Space Science Concepts: Strategies for Concept-Building in Elementary Teacher Preparation

    ERIC Educational Resources Information Center

    Bulunuz, Nermin; Jarrett, Olga S.

    2009-01-01

    This research is concerned with preservice teacher understanding of six earth and space science concepts that are often taught in elementary school: the reason for seasons, phases of the moon, why the wind blows, the rock cycle, soil formation, and earthquakes. Specifically, this study examines the effect of readings, hands-on learning stations,…

  5. Une nouvelle approche du contenu thematique et situationnel d'une methode audio-visuelle: 'C'est le Printemps' (A New Approach to Thematic and Situational Content in an Audio-Visual Method: 'C'est le Printemps'). Acts of the Colloquium of the Swiss Interuniversity Commission for Applied Linguistics. CILA Bulletin, No. 26.

    ERIC Educational Resources Information Center

    Gschwind-Holtzer, G.

    This study attempts to demonstrate that the choice of material on the thematic and situational level has a bearing on linguistic concepts. The critique is divided into three main sections dealing with: (1) themes and situations, or the world view of audio-visual methods; (2) themes and situations in a particular text, "C'est le printemps;" and (3)…

  6. The microbial cell cycle

    SciTech Connect

    Nurse, P.; Streiblova, E.

    1984-01-01

    This book concentrates on the major problems of cell cycle control in microorganisms. A wide variety of microorganisms, ranging from bacteria and yeasts to hyphal fungi, algae, and ciliates are analyzed, with emphasis on the basic similarities among the organisms. Different ways of looking at cell cycle control which emphasize aspects of the problem such as circadian rhythms, limit cycle oscillators, and cell size models, are considered. New approaches such as the study of cell cycle mutants, and cloning of cell cycle control genes are also presented.

  7. Continuing education in nursing: a concept analysis.

    PubMed

    Gallagher, Lorraine

    2007-07-01

    The importance of continuing education for nurses has been increasingly emphasized in the nursing literature since the beginning of the profession. The concept of continuing education is often used as a substitute for associated terms such as continuing professional development and lifelong learning, thus highlighting a need for its clarification. The purpose of this article is to explain and describe continuing education, in order to encourage a broader understanding of the concept among nurses. The concept analysis is directed by Rodgers' [Rodgers, B.L., 1989. Concept analysis and the development of nursing knowledge: the evolutionary cycle. Journal of Advanced Nursing 14, 330-335] 'evolutionary approach' which is viewed as an ongoing dynamic process, and one that identifies the shared meaning of concepts. Examining everyday discourse used in the nursing literature identified the critical attributes, antecedents and consequence of continuing education in nursing. As a result, the emerging attributes of the concept are synthesised into a conceptual model. The article concludes with an exploration of the application of the concept of continuing education within nursing and its implications for professional development.

  8. Integral fast reactor concept inherent safety features

    SciTech Connect

    Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

    1987-01-01

    The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFT development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: 1) a liquid metal (sodium) coolant, 2) a pool-type reactor primary system configuration, 3) an advanced ternary alloy metallic fuel, and 4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS).

  9. Integral Fast Reactor concept inherent safety features

    SciTech Connect

    Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFR development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: (1) a liquid metal (sodium) coolant, (2) a pool-type reactor primary system configuration, (3) an advanced ternary alloy metallic fuel, and (4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS).

  10. A combined cycle engine test facility

    NASA Astrophysics Data System (ADS)

    Engers, R.; Cresci, D.; Tsai, C.

    Rocket-Based Combined-Cycle (RBCC) engines intended for missiles and/or space launch applications incorporate features of rocket propulsion systems operating in concert with airbreathing engine cycles. Performance evaluation of these types of engines, which are intended to operate from static sea level take-off to supersonic cruise or accerlerate to orbit, requires ground test capabilities which integrate rocket component testing with airbreathing engine testing. A combined cycle engine test facility has been constructed in the General Applied Science Laboratories, Inc. (GASL) Aeropropulsion Test Laboratory to meet this requirement. The facility was designed to support the development of an innovative combined cycle engine concept which features a rocket based ramjet combustor. The test requirements included the ability to conduct tests in which the propulsive force was generated by rocket only, the ramjet only and simultaneous rocket and ramjet power (combined cycle) to evaluate combustor operation over the entire engine cycle. The test facility provides simulation over the flight Mach number range of 0 to 8 and at various trajectories. The capabilities of the combined cycle engine test facility are presented.

  11. A combined cycle engine test facility

    SciTech Connect

    Engers, R.; Cresci, D.; Tsai, C.

    1995-09-01

    Rocket-Based Combined-Cycle (RBCC) engines intended for missiles and/or space launch applications incorporate features of rocket propulsion systems operating in concert with airbreathing engine cycles. Performance evaluation of these types of engines, which are intended to operate from static sea level take-off to supersonic cruise or accerlerate to orbit, requires ground test capabilities which integrate rocket component testing with airbreathing engine testing. A combined cycle engine test facility has been constructed in the General Applied Science Laboratories, Inc. (GASL) Aeropropulsion Test Laboratory to meet this requirement. The facility was designed to support the development of an innovative combined cycle engine concept which features a rocket based ramjet combustor. The test requirements included the ability to conduct tests in which the propulsive force was generated by rocket only, the ramjet only and simultaneous rocket and ramjet power (combined cycle) to evaluate combustor operation over the entire engine cycle. The test facility provides simulation over the flight Mach number range of 0 to 8 and at various trajectories. The capabilities of the combined cycle engine test facility are presented.

  12. ``Fast Track'' nuclear thermal propulsion concept

    NASA Astrophysics Data System (ADS)

    Johnson, Richard A.; Zweig, Herbert R.; Cooper, Martin H.; Wett, Jack

    1993-01-01

    The objective of the Space Exploration Initiative (``America at the Threshold...,'' 1991) is the exploration of Mars by man in the second decade of the 21st century. The NASA ``Fast Track'' approach (NASA-LeRC Presentation, 1992) could accelerate the manned exploration of Mars to 2007. NERVA-derived nuclear propulsion represents a viable near-term technology approach to accomplish the accelerated schedule. Key milestones in the progression to the manned Mars mission are (1) demonstration of TRL-6 for the man-rateable system by 1999, (2) a robotic lunar mission by 2000, (3) the first cargo mission to Mars by 2005, and (4) the piloted Mars mission in 2007. The Rocketdyne-Westinghouse concept for nuclear thermal propulsion to achieve these milestones combines the nuclear reactor technology of the Rover/NERVA programs and the state-of-the-art hardware designs from hydrogen-fueled rocket engine successes like the Space Shuttle Main Engine (SSME).

  13. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-10-01

    Cycle solaire; Voyager 1; Geysers aux pôles martiens; Panètes extrasolaires; Systèmes planétaires en formation; Spirales de poussière; NGC 6397; Protogalaxies lointaines; Deutérium; Économie cosmique; AKARI; Travaux inutiles (les avatars du mot planète)

  14. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2009-09-01

    Apollo vu par LRO; Impact; Comètes et astéroïdes; Eclipse; Encelade; Vénus; Climat et cycles solaires; Galaxies gamma; Positrons; Supernovae lointaines; Trous noirs intermédiaires; Galaxies ratées; La luminosité des supenovae Ia; Populations de pulsars gamma

  15. Resilience - A Concept

    DTIC Science & Technology

    2016-04-05

    Image designed by Diane Fleischer Resilience—A CONCEPT Col Dennis J. Rensel, USAF (Ret.) Resilience takes on many definitions and ideas depending...2015, Vol. 22 No. 3 : 294–324 A Publication of the Defense Acquisition University http://www.dau.mil Resilience as a term has as many definitions as...people who talk about it. What if resiliency is treated as a concept? How do you measure a concept? In reviewing many definitions , “each [ definition

  16. Evolving Ethical Concepts

    ERIC Educational Resources Information Center

    Potter, Van Rensselaer

    1977-01-01

    Discusses the role of the scientist in changing ethical concepts from simple interpersonal and theological imperatives towards "survival imperatives that must form the core of environmental bioethics." (CS)

  17. L’apport de la dermoscopie dans le carcinome basosquameux

    PubMed Central

    Elmahi, Hakima; Lahlou, Asmae; Baybay, Hanane; Gallouj, Salim; Mernissi, Fatima Zahra; Reggad, Fatima Zahra; Harmouch, Taoufik

    2016-01-01

    Le carcinome basosquameux (CBS) est un cancer cutané rare qui présente des zones de carcinome basocellulaire (CBC) et de carcinome épidermoïde (SCC) et une zone de transition entre elles. Cependant, les caractéristiques dermoscopiques du BSC ne sont pas bien décrites dans la littérature, sauf deux études. Le but du présent cas était de mieux identifier et clarifier la contribution de la dermoscopie dans le diagnostic du BSC, malgré que la confirmation reste toujours histologique. PMID:28293368

  18. Les Hemorragies Gastroduodenales de Stress Chez le Brule Grave

    PubMed Central

    Siah, S.; Fouadi, F.E.; Ababou, K.; Nassim Sabah, T.; Ihrai, I.

    2008-01-01

    Summary Les Auteurs rapportent trois observations d'hémorragies gastroduodénales de stress chez le brûlé grave. Ils rappellent l'importance des mesures thérapeutiques qui doivent être prises chez le brûlé grave, comme le traitement du choc, du sepsis, des plaies et de la douleur, la nutrition entérale précoce et l'oxygénothérapie. Tout cela permet de réduire les facteurs de risque de survenue d'une hémorragie gastroduodénale de stress. PMID:21991137

  19. Automated Verification of Design Patterns with LePUS3

    NASA Technical Reports Server (NTRS)

    Nicholson, Jonathan; Gasparis, Epameinondas; Eden, Ammon H.; Kazman, Rick

    2009-01-01

    Specification and [visual] modelling languages are expected to combine strong abstraction mechanisms with rigour, scalability, and parsimony. LePUS3 is a visual, object-oriented design description language axiomatized in a decidable subset of the first-order predicate logic. We demonstrate how LePUS3 is used to formally specify a structural design pattern and prove ( verify ) whether any JavaTM 1.4 program satisfies that specification. We also show how LePUS3 specifications (charts) are composed and how they are verified fully automatically in the Two-Tier Programming Toolkit.

  20. A model for the construction of elementary concepts

    NASA Astrophysics Data System (ADS)

    von Glasersfeld, Ernst

    1999-03-01

    In his paper Les épistémologies constructivistes: Un nouveau commencement (Sciences de la Société, n°40, 1997), Jean-Louis Le Moigne poses the question: "Le rêve d'une connaissance autoréférentielle se fondant sur elle-même, est sans doute fascinant … Mais est-il scientifiquement raisonnable?". Building on the work of Jean Piaget, I shall try to show through a developmental analysis of elementary, scientifically relevant concepts, such as `change', `object permanence', `space', and `time', that the notion of the thinking subject's construction of knowledge constitutes a more reasonable foundation for science than the traditional belief in the representation of objective reality.

  1. Evaluation of vapor compression cycles using nonazeotropic refrigerant mixtures

    NASA Astrophysics Data System (ADS)

    Merriam, Richard L.

    A comprehensive investigation is carried out, on a systematic and consistent basis, to explore a range of advanced heat pump cycle concepts using nonazeotropic refrigerants for COP enhancement and capacity modulation along with the trade-offs associated with refrigerant mixture selection. The objectives of the study were to: identify candidate nonazeotropic mixtures and advanced heat pump cycle concepts with emphasis on their potential for single-speed capacity modulation with mixture composition control; assess the effect of conjunction with nonazeotropic mixture cycles; evaluate the cycles analytically and recommend the most promising cycles and mixtures for further development; and provide recommendations relating to the needs for additional refrigerant property data, experimental studies of basic heat transfer phenomena with mixed refrigerants, development of system components, and/or more detailed modeling of specific components.

  2. Simultaneously cycled NMR spectroscopy.

    PubMed

    Parish, David M; Szyperski, Thomas

    2008-04-09

    Simultaneously cycled (SC) NMR was introduced and exemplified by implementing a set of 2-D [1H,1H] SC exclusive COSY (E.COSY) NMR experiments, that is, rf pulse flip-angle cycled (SFC), rf pulse phase cycled (SPC), and pulsed field gradient (PFG) strength cycled (SGC) E.COSY. Spatially selective 1H rf pulses were applied as composite pulses such that all steps of the respective cycles were affected simultaneously in different slices of the sample. This increased the data acquisition speed for an n-step cycle n-fold. A high intrinsic sensitivity was achieved by defining the cycles in a manner that the receiver phase remains constant for all steps of the cycle. Then, the signal resulting from applying the cycle corresponded to the sum of the signals from all steps of the cycle. Hence, the detected free induction decay did not have to be separated into the contributions arising from different slices, and read-out PFGs, which not only greatly reduce sensitivity but also negatively impact lineshapes in the direct dimension, were avoided. The current implementation of SFC E.COSY reached approximately 65% of the intrinsic sensitivity of the conventional phase cycled congener, making this experiment highly attractive whenever conventional data acquisition is sampling limited. Highly resolved SC E.COSY yielding accurate 3J-coupling values was recorded for the 416 Da plant alkaloid tomatidine within 80 min, that is, 12 times faster than with conventional phase cycled E.COSY. SC NMR is applicable for a large variety of NMR experiments and thus promises to be a valuable addition to the arsenal of approaches for tackling the NMR sampling problem to avoid sampling limited data acquisition.

  3. Vuilleumier Cycle Cryogenic Refrigeration

    DTIC Science & Technology

    1976-04-01

    WORDS (Continue on reverse side if necessary and identify by block number) Cryogenic Refrigerator Vuilleumier Cycle 20. ABSTRACT (Continue on reverse ...The energy added to the gas was stored in the regenerator packing, or matrix, by gas flow in the reverse direction during a previous part of the cycle ...AFFDL-TR-76-17 VUILLEUMIER CYCLE CRYOGENIC REFRIGERATION ENVIRONMENTAL CONTROL BRANCH 4 VEHICLE EQUIPMENT DIVISION APRIL 1976 TECHNICAL REPORT AFFDL

  4. Le point sur les amas de galaxies

    NASA Astrophysics Data System (ADS)

    Pierre, M.

    galaxies jouent donc un rôle de premier plan dans toute étude cosmologique et par conséquent, sont indispensables à notre compréhension globale de l'univers. Dans l'introduction générale, nous détaillons cet aspect fondamental en montrant comment l'étude des amas peut contribuer à contraindre les scénarios cosmologiques. Une fois le contexte scientifique délimité, les chapitres suivants s'attachent à présenter les diverses propriétés des amas et leur évolution cosmique observée dans diverses longueurs d'onde principalement dans les domaines visible (galaxies), X (gaz) et radio (gaz et particules). Nous verrons que l'étude détaillée d'un amas implique celle de l'interaction entre ses différentes composantes et est un passage obligé pour remonter au paramètre ultime (ou premier) qu'est sa masse. Loin d'être un détour ennuyeux, ceci sera l'occasion d'aborder des phénomènes physiques extrêmement variés tel l'aspect multi-phases du milieu intra-amas, les sursauts de formation d'étoiles et l'évolution morphologique des galaxies capturées par les amas, ou bien encore, l'interaction entre le plasma intra-amas et les particules relativistes accélérées lors de la fusion entre deux amas. Bien sûr, pour chaque longueur d'onde, nous ne manquerons pas de décrire simplement les techniques d'observation et d'analyse mises en oeuvre ; celles-ci sont particulièrement intéressantes dans le cas de l'instrumentation spatiale. Nous terminerons en présentant des projets d'observatoires pour l'horizon 2010 et leur impact prévu sur l'étude des amas de galaxies.

  5. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2007-09-01

    Anions interstellaires; S Orionis; Altaîr; Courants stellaires; Etoiles jeunes; 2MASSW J1207334-393254; Alpha Andromède; Etoiles à neutrons (1); LH54-425; AGNs invisibles; Deux supernovae; Les GRBs seon Swift; Peser les trous noirs; Formation de trous noirs; Trou noir; ondes gravitationnelles : Virgo entre dans sa phase d'exploitation scientifique; Amas de galaxies actifs; Amas de galaxies; Galaxies actives d'amas; L'univers statique: le retour; Macho; Exoplanètes; Exoplanètes habitables?; Exoplanètes habitables? (suite); Une année d'un an; Une année de 31 heures; Valse des Jupiters; Disque de HD 15115; Impact majeur; Planètes isolées; Super-Jupiter; Impact et mini-extinction; L'effet Pioneer; Toungouska; Spéléo martienne; Autres lunes dactives; Encelade; Hypérion; Pluton dépassé; Satellites d'Uranus; Titan

  6. Core Concepts of Kinesiology.

    ERIC Educational Resources Information Center

    Hudson, Jackie L.

    1995-01-01

    Core concepts of kinesiology are the basis of communication about movement that facilitate progression of skill levels. The article defines and exemplifies each of 10 core concepts: range of motion, speed of motion, number of segments, nature of segments, balance, coordination, compactness, extension at release/contact, path of projection, and…

  7. The Self Concept.

    ERIC Educational Resources Information Center

    Fitzgibbon, Ann

    The purpose of this paper is to increase awareness of the self concept as a variable, to indicate what is known about the self concept from existing research, to discuss its importance to the school and its effect on learning, and to offer a method of assessment which is tied to a definition arbitrarily made as a starting point for researchers. A…

  8. Avionics technology - system concepts

    NASA Technical Reports Server (NTRS)

    Bull, J. S.; Huntoon, R. B.

    1984-01-01

    Avionics System Concepts to meet technology needs of advanced helicopter integrated cockpit design are identified. Specific avionics system concepts which should be conducted and/or support by NASA to most effectively aid industry in advanced helicopter integrated cockpit design are also identified. Candidate Missions and Mission Requirements to meet technology needs are considered.

  9. Values Concepts and Techniques.

    ERIC Educational Resources Information Center

    National Education Association, Washington, DC.

    This book contains 29 articles for elementary and secondary teachers dealing with fundamental concepts and teaching techniques in values education. Part one of the book deals with concepts. Louis E. Raths examines valuing and its relationship to freedom and intelligence. The cognitive developmental approach to moral education is discussed by…

  10. New Concepts of Work.

    ERIC Educational Resources Information Center

    Canadian Council on Social Development, Ottawa (Ontario).

    The two-day Canadian conference focused on the topics: "Why are new concepts of work emerging?" and "How can we encourage desirable new work concepts in our society?" Following an introductory summary by David P. Ross, Stephen Peitchinis (Dean, School of Business Administration, University of Calgary) presented the economic…

  11. Learning Our Concepts

    ERIC Educational Resources Information Center

    Laverty, Megan J.

    2009-01-01

    Richard Stanley Peters appreciates the centrality of concepts for everyday life, however, he fails to recognize their pedagogical dimension. He distinguishes concepts employed at the first-order (our ordinary language-use) from second-order conceptual clarification (conducted exclusively by academically trained philosophers). This distinction…

  12. Data Transmission Concepts.

    ERIC Educational Resources Information Center

    Christenson, Chris

    1995-01-01

    Introduces some basic concepts related to the transmission of data from a computer to its peripherals to help distance educators make decisions regarding computer equipment purchases for their institutions. The following data transmission concepts are described: cables, serial and parallel, synchronous and asynchronous, bandwidth, and analog and…

  13. Thinking to Learn Concepts.

    ERIC Educational Resources Information Center

    Parker, Walter C.

    1988-01-01

    States that programs which link the teaching of thinking with content have the greatest instructional value. Presents a concept formation lesson, based on the works of Taba (1967) and Ehrenberg (1978), which requires students to learn a concept by studying several examples and noting their similarities and differences. Includes a sample…

  14. Teach Concepts, Not Words.

    ERIC Educational Resources Information Center

    Williamson, Leon E.

    Since concepts are the mental divisions man makes among the concrete and abstract phenomena of his environment so he may generate, maneuver, and control their relationships in a manner ot satisfy his physical, emotional, social, and aesthetic needs, concepts should be the vortex of intelligence. Too often students are taught as if they lack a…

  15. Imagerie Resolue dans le Temps des Photons et Neutres Metastables Emis D'une Surface Par Stimulation Electronique

    NASA Astrophysics Data System (ADS)

    Leclerc, Gregoire

    L'appareil que nous presentons ici a ete mis au point pour permettre d'accumuler des images numeriques, resolues dans le temps, de la desorption par stimulation electronique (DSE) d'ions positifs et negatifs, de photons et de neutres metastables, tout en conservant des capacites de base de diffraction d'electrons lents (DEL) et de transmission d'electrons lents (TEL). Le spectrometre comporte un monochromateur d'electrons a secteur cylindrique de 127^ circ dont l'optique de sortie permet la focalisation du faisceau d'electrons sur une large gamme d'energies. Le detecteur consiste en un empilement de galettes de microcanaux et d'une anode resistive a encodage de division de charges. La reponse spatiale du detecteur a ete calibree et plusieurs causes de non-linearite ont ete localisees et corrigees. Des methodes de correction materielle et logicielle des distorsions spatiales sont presentees. La resolution temporelle des evenements est obtenue en pulsant le faisceau d'electrons, et de facon synchrone la detection, laquelle est couplee a un micro-ordinateur. La premiere partie de ce travail est consacree a la caracterisation du spectrometre et la presentation de nombreux parametres operationnels, obtenus soit au moment de la conception, soit experimentalement. Suit la presentation de donnees de DEL et de DSE pour le systeme Ar/Pt(111) en films minces a 15K. Les sequences temporelles d'images de metastables d'Ar desorbes ont revele la presence de plusieurs populations distinctes, ayant des distributions angulaires et distributions d'energie cinetique que nous avons pu separer. Les fonctions d'excitation de l'emission de photons et de la desorption de differentes composantes de metastables, ainsi que la dependance de ces signaux sur l'epaisseur des films d'Ar, sont aussi presentees et analysees. Les techniques que nous avons developpees ont permis de cerner les mecanismes en jeu pour la desorption et la luminescence.

  16. Conception d'un generateur miniaturise d'ondes mecaniques

    NASA Astrophysics Data System (ADS)

    Riel, Louise-Philippe

    De nos jours, les maladies cardiaques représentent la première cause de décès dans le monde. Parmi ces maladies, les occlusions coronariennes occupent un rôle important. Aussi, 10 à 15 % de la population souffre de calculs urinaires et ces pourcentages augmentent d'année en année dans les pays industrialisés. Considérant ces données et le fait que les outils médicaux actuels ne permettent pas de répondre à l'ensemble des besoins exigés par ces domaines, il existe une opportunité intéressante pour le développement d'appareils mieux adaptés. Le présent mémoire a pour but de démontrer le potentiel technologique d'un générateur miniaturisé d'ondes mécaniques comme futur dispositif médical dans les domaines de la lithotritie intracorporelle et de la cardiologie d'intervention. Le générateur proposé exploite les ondes acoustiques (profil de pression) pour briser les calculs urinaires ou traverser les occlusions coronariennes. Le concept présenté vise à être plus efficace, plus sécuritaire et moins dispendieux que les appareils actuels. Pour parvenir à générer le profil de, pression désiré à l'extrémité d'une longue et mince tige, un processus d'amplification exploitant la focalisation des ondes dans un solide et la dispersion dans un guide d'ondes est utilisé. Ce processus nécessite une étape préliminaire de calibration qui permet de caractériser les propriétés acoustiques des milieux de propagation (concentrateur et guide dispersif). Tirant profit du retournement temporel, il est ensuite possible de concentrer spatialement et de compresser temporellement le signal de calibration pour former le profil de pression désiré. Le gain combiné de ces méthodes permettent de respecter les requis fixés pour l'appareil. Le prototype fabriqué est composé d'une source acoustique convergente, d'un guide d'ondes dispersif ainsi que d'un réducteur de section. La source acoustique comprend sept transducteurs pi

  17. Low-cycle thermal fatigue

    NASA Technical Reports Server (NTRS)

    Halford, G. R.

    1986-01-01

    A state-of-the-art review is presented of the field of thermal fatigue. Following a brief historical review, the concept is developed that thermal fatigue can be viewed as processes of unbalanced deformation and cracking. The unbalances refer to dissimilar mechanisms occurring in opposing halves of thermal fatigue loading and unloading cycles. Extensive data summaries are presented and results are interpreted in terms of the unbalanced processes involved. Both crack initiation and crack propagation results are summarized. Testing techniques are reviewed, and considerable discussion is given to a technique for thermal fatigue simulation, known as the bithermal fatigue test. Attention is given to the use of isothermal life prediction methods for the prediction of thermal fatigue lives. Shortcomings of isothermally-based life prediction methods are pointed out. Several examples of analyses and thermal fatigue life predictions of high technology structural components are presented. Finally, numerous dos and don'ts relative to design against thermal fatigue are presented.

  18. Some Aspects of the Teaching of "-Guo" and "-Le"

    ERIC Educational Resources Information Center

    Ma, Jing-heng S.

    1977-01-01

    This paper examines the two markers of Mandarin Chinese, "-guo" and "-le," and focuses primarily on areas of difficulty that the non-native speaker may encounter due to confusion of these markers. (CHK)

  19. Lymphoscintigraphy (LS) in lymphedema (LE) of the extremities

    SciTech Connect

    Gloviczki, P.; Vaqueiro, M.; Fisher, J.; Schirger, A.; Dewanjee, M.K.; Hollier, L.H.; Wahner, H.W.

    1985-05-01

    Twenty-two patients with primary and secondary LE and one with lipedema had LS using 0.4-0.6 mCi of Tc-99mSb2Sb3 subcutaneous at the second interdigital space. Three had excisional surgery, in four patients lympho-venous anastomosis (LVA) was attempted following LS. Results are presented in this paper. This study concludes that LS is a noninvasive method without side effects that visualizes the pattern of the lymphatic system in LE. If lymph channels were seen, LVA could be performed. LS seems adequate for patient selection and follow-up after LVA. It differentiated LE from lipedema. Image patterns or quantitative studies could not differentiate between primary and secondary LE.

  20. Microscopic Description of Le Châtelier's Principle

    NASA Astrophysics Data System (ADS)

    Novak, Igor

    2005-08-01

    The analysis based on microscopic descriptors (energy levels and their populations) is given that provides visualization of free energies and conceptual rationalization of Le Châtelier's principle. The misconception "nature favors equilibrium" is highlighted.

  1. Life Cycle Costing in Government Procurement.

    DTIC Science & Technology

    1985-05-01

    majority of this work, treatment is also given to state procurement policies . Primary Sources: Decisions of the Comptroller General Federal...decisions has become clear to a number of procurement policy makers.2 While still quite limited, the consideration of post-acquisition costs is...make no mention of life cycle Ii costing. However, the concepts and policies dictated by 29 _ Comp. Gen. Report B-178214, May 21, 1973, where the

  2. EDOS operations concept and development approach

    NASA Technical Reports Server (NTRS)

    Knoble, G.; Garman, C.; Alcott, G.; Ramchandani, C.; Silvers, J.

    1994-01-01

    The Earth Observing System (EOS) Data and Operations System (EDOS) is being developed by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) for the capture, level zero processing, distribution, and backup archiving of high speed telemetry data received from EOS spacecraft. All data received will conform to the Consultative Committee for Space Data Standards (CCSDS) recommendations. The major EDOS goals are to: (1) minimize EOS program costs to implement and operate EDOS; (2) respond effectively to EOS growth requirements; and (3) maintain compatibility with existing and enhanced versions of NASA institutional systems required to support EOS spacecraft. In order to meet these goals, the following objectives have been defined for EDOS: (1) standardize EDOS interfaces to maximize utility for future requirements; (2) emphasize life-cycle cost (LCC) considerations (rather than procurement costs) in making design decisions and meeting reliability, maintainability, availability (RMA) and upgradability requirements; (3) implement data-driven operations to the maximum extent possible to minimize staffing requirements and to maximize system responsiveness; (4) provide a system capable of simultaneously supporting multiple spacecraft, each in different phases of their life-cycles; (5) provide for technology insertion features to accommodate growth and future LCC reductions during the operations phase; and (6) provide a system that is sufficiently robust to accommodate incremental performance upgrades while supporting operations. Operations concept working group meetings were facilitated to help develop the EDOS operations concept. This provided a cohesive concept that met with approval of responsible personnel from the start. This approach not only speeded up the development process by reducing review cycles, it also provided a medium for generating good ideas that were immediately molded into feasible concepts. The operations concept

  3. CIM - A Manufacturing Paradigm (Le CIM - Un Nouveau Modele Industriel),

    DTIC Science & Technology

    1986-07-01

    fait la plupart des entreprises , ont affind le module de "Rgvolution industrielle". Nous vivons A l’poque du spdcialiste. Toutefois, le modale de sp...program will serve as an umbrella under which specific projects are planned, financed , managed, and imple- mented. Well defined corporate goals must be...assets. Through an integration of financing strategies an enterprise can focus on capital investment in shared, value-added assets such as databases

  4. An Integrated Approach to Life Cycle Analysis

    NASA Technical Reports Server (NTRS)

    Chytka, T. M.; Brown, R. W.; Shih, A. T.; Reeves, J. D.; Dempsey, J. A.

    2006-01-01

    Life Cycle Analysis (LCA) is the evaluation of the impacts that design decisions have on a system and provides a framework for identifying and evaluating design benefits and burdens associated with the life cycles of space transportation systems from a "cradle-to-grave" approach. Sometimes called life cycle assessment, life cycle approach, or "cradle to grave analysis", it represents a rapidly emerging family of tools and techniques designed to be a decision support methodology and aid in the development of sustainable systems. The implementation of a Life Cycle Analysis can vary and may take many forms; from global system-level uncertainty-centered analysis to the assessment of individualized discriminatory metrics. This paper will focus on a proven LCA methodology developed by the Systems Analysis and Concepts Directorate (SACD) at NASA Langley Research Center to quantify and assess key LCA discriminatory metrics, in particular affordability, reliability, maintainability, and operability. This paper will address issues inherent in Life Cycle Analysis including direct impacts, such as system development cost and crew safety, as well as indirect impacts, which often take the form of coupled metrics (i.e., the cost of system unreliability). Since LCA deals with the analysis of space vehicle system conceptual designs, it is imperative to stress that the goal of LCA is not to arrive at the answer but, rather, to provide important inputs to a broader strategic planning process, allowing the managers to make risk-informed decisions, and increase the likelihood of meeting mission success criteria.

  5. Searching the animal psyche with Charles Le Brun.

    PubMed

    Cohen, Sarah R

    2010-07-01

    Around 1670 the French court painter and Academician Charles Le Brun produced a series of drawings featuring naturalistic animal heads, as well as imaginary heads in which he refashioned various nonhuman animal species to make humanoid physiognomies. What were the purpose and significance of these unusual works? I argue that they show Le Brun's interest in what we today would call animal psychology: focusing upon the sensory organs and their connections with the animal's brain, Le Brun studied his animals as conscious protagonists of the natural realm. One source that may have served him in this project was Marin Cureau de La Chambre's De la Connoissance des bestes of 1645, in which the physician argued that animals possess a conscious soul grounded in the senses. However, Le Brun's animal-humans have no clear place in the artist's taxonomy--nor, indeed, in any seventeenth-century understandings of species. It is rather John Locke, at his most skeptical, who offers the best parallel in the realm of natural philosophy to Le Brun's unsettling animal-humans. Probably without meaning to, Le Brun demonstrated through his eerie, boundary-crossing creatures the limits of visual classification.

  6. Transmaxillary Sinus Approach for Le Fort II Osteotomy

    PubMed Central

    Fukawa, Toshihiko; Hirakawa, Takashi; Satake, Toshihiko; Maegawa, Jiro

    2016-01-01

    Summary: The Le Fort II osteotomy is a relatively rare operation. The posterior wall osteotomy of the maxillary sinus (MS) is often difficult for Le Fort III. We developed the transmaxillary sinus approach (TSA) for the Le Fort II osteotomy that cuts the posterior wall of the MS directly. This report illustrates this easy-to-use procedure for the Le Fort II osteotomy in syndromic craniosynostosis. This procedure was performed in an 18-year-old patient with Apert syndrome and a 15-year-old patient with Pfeiffer syndrome. The thin anterior walls of the MS were removed through an intraoral approach to look inside the MS. Then, the posterior walls were cut by chisel under direct vision using light. The other osteotomy was performed as usual. Distraction osteogenesis with internal and external devices was used in combination. The advantages of TSA are the direct posterior wall osteotomy of the MS with no down fracture and minimal invasiveness to the mucosa of the MS under direct vision. However, the disadvantage is that TSA becomes a blind procedure in a case with no MS or hypoplasia. We developed the TSA for the Le Fort II osteotomy, which could provide direct observation and perform the posterior wall osteotomy of the MS without down fracture. We believe that TSA is an effective surgical procedure for the Le Fort II osteotomy. PMID:27014548

  7. Le Soleil et ses relations avec la Terre

    NASA Astrophysics Data System (ADS)

    Lang, Kenneth; Heidmann, M.

    C'est le 2e livre de K. Lang publié en français, considéré comme texte complementaire au célèbre Vagabonds de l'Espace qui avait gagné en 1994 le prix du livre d'astronomie en France. Maintenant l'auteur se concentre sur le système le plus élémentaire: l'étoile et son planète, et choisit celui qui est le plus intéressant pour nous: le Soleil et la Terre. Il a accumulé les observations terrestres et les plus récentes effectuées par des observatoires spatiales, et ceux des météorologues et géophysiciens, et nous présente un panorama fascinant du Soleil et ses relations avec la Terre. C'est la physique qui a les conséquences les plus fondamentales aux événements qui influencent notre environment, notre vie et même la condition humaine y inclu les arts et la litérature.

  8. The Oxygen Cycle.

    ERIC Educational Resources Information Center

    Swant, Gary D.

    Produced for primary grades, this booklet provides study of the oxygen-carbon dioxide cycle in nature. Line drawings, a minimum amount of narrative, and a glossary of terms make up its content. The booklet is designed to be used as reading material, a coloring book, or for dramatic arts with students acting out parts of the cycle. This work was…

  9. Seeing the Carbon Cycle

    ERIC Educational Resources Information Center

    Drouin, Pamela; Welty, David J.; Repeta, Daniel; Engle-Belknap, Cheryl A.; Cramer, Catherine; Frashure, Kim; Chen, Robert

    2006-01-01

    In this article, the authors present a classroom experiment that was developed to introduce middle school learners to the carbon cycle. The experiment deals with transfer of CO[subscript 2] between liquid reservoirs and the effect CO[subscript 2] has on algae growth. It allows students to observe the influence of the carbon cycle on algae growth,…

  10. The carbon cycle revisited

    NASA Technical Reports Server (NTRS)

    Bolin, Bert; Fung, Inez

    1992-01-01

    Discussions during the Global Change Institute indicated a need to present, in some detail and as accurately as possible, our present knowledge about the carbon cycle, the uncertainties in this knowledge, and the reasons for these uncertainties. We discuss basic issues of internal consistency within the carbon cycle, and end by summarizing the key unknowns.

  11. Teaching the Krebs Cycle.

    ERIC Educational Resources Information Center

    Akeroyd, F. Michael

    1983-01-01

    Outlines a simple but rigorous treatment of the Krebs Cycle suitable for A-level Biology students. The importance of the addition of water molecules in various stages of the cycle is stressed as well as the removal of hydrogen atoms by the oxidizing enzymes. (JN)

  12. Your Menstrual Cycle

    MedlinePlus

    ... your best Fighting germs Your sexuality What are STDs and STIs? Seeing the doctor Quizzes Links to more information on girls' ... What happens during your menstrual cycle The menstrual cycle includes not just your period, but the rise and fall of hormones and other body changes ...

  13. Rock Cycle Roulette.

    ERIC Educational Resources Information Center

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  14. Power Plant Cycling Costs

    SciTech Connect

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  15. Le Point sur la Pharmacologie des Agents Anesthesiques Chez le Brule Grave

    PubMed Central

    Siah, S.; Ababou, K.; Benziane, H.; El Jaoudi; Bensghir, M.; Bakali, H.; El Wali, A.; Ihrai, I.; Drissi, N.K.

    2008-01-01

    Summary La pharmacologie des agents anesthésiques chez le brûlé est variable et imprévisible. Dans les premières 48 h, il y a une hypovolémie avec chute du débit cardiaque et des fuites plasmatiques. Après 48 h, il y a une hypervolémie avec augmentation du débit cardiaque, hypermétabolisme et la clearance des médicaments est augmentée. Parmi les facteurs de déséquilibre, on retrouve les variations des protéines plasmatiques. Deux protéines sont importantes chez le brûlé grave : l'albumine et l'alpha 1- glycoprotéine. Leur taux varie beaucoup au cours de l'évolution de la brûlure. Les agents anesthésiques dont la liaison avec ces deux protéines est prédominante verront leur pharmacocinétique modifiée. L'anesthésiste-réanimateur du service des brûlés va maîtriser ces notions pharmacologiques pour utiliser à bon escient les agents anesthésiques. PMID:21991108

  16. Predicting the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2009-01-01

    The 11-year sunspot cycle was discovered by an amateur astronomer in 1844. Visual and photographic observations of sunspots have been made by both amateurs and professionals over the last 400 years. These observations provide key statistical information about the sunspot cycle that do allow for predictions of future activity. However, sunspots and the sunspot cycle are magnetic in nature. For the last 100 years these magnetic measurements have been acquired and used exclusively by professional astronomers to gain new information about the nature of the solar activity cycle. Recently, magnetic dynamo models have evolved to the stage where they can assimilate past data and provide predictions. With the advent of the Internet and open data policies, amateurs now have equal access to the same data used by professionals and equal opportunities to contribute (but, alas, without pay). This talk will describe some of the more useful prediction techniques and reveal what they say about the intensity of the upcoming sunspot cycle.

  17. MHD Integrated Topping Cycle Project

    SciTech Connect

    Not Available

    1992-01-01

    The overall objective of the project is to design and construct prototypical hardware for an integrated MHD topping cycle, and conduct long duration proof-of-concept tests of integrated system at the US DOE Component Development and Integration Facility in Butte, Montana. The results of the long duration tests will augment the existing engineering design data base on MHD power train reliability, availability, maintainability, and performance, and will serve as a basis for scaling up the topping cycle design to the next level of development, an early commercial scale power plant retrofit. The components of the MHD power train to be designed, fabricated, and tested include: A slagging coal combustor with a rated capacity of 50 MW thermal input, capable of operation with an Eastern (Illinois {number sign}6) or Western (Montana Rosebud) coal, a segmented supersonic nozzle, a supersonic MHD channel capable of generating at least 1.5 MW of electrical power, a segmented supersonic diffuser section to interface the channel with existing facility quench and exhaust systems, a complete set of current control circuits for local diagonal current control along the channel, and a set of current consolidation circuits to interface the channel with the existing facility inverter.

  18. MHD Integrated Topping Cycle Project

    SciTech Connect

    Not Available

    1992-03-01

    The Magnetohydrodynamics (MHD) Integrated Topping Cycle (ITC) Project represents the culmination of the proof-of-concept (POC) development stage in the US Department of Energy (DOE) program to advance MHD technology to early commercial development stage utility power applications. The project is a joint effort, combining the skills of three topping cycle component developers: TRW, Avco/TDS, and Westinghouse. TRW, the prime contractor and system integrator, is responsible for the 50 thermal megawatt (50 MW{sub t}) slagging coal combustion subsystem. Avco/TDS is responsible for the MHD channel subsystem (nozzle, channel, diffuser, and power conditioning circuits), and Westinghouse is responsible for the current consolidation subsystem. The ITC Project will advance the state-of-the-art in MHD power systems with the design, construction, and integrated testing of 50 MW{sub t} power train components which are prototypical of the equipment that will be used in an early commercial scale MHD utility retrofit. Long duration testing of the integrated power train at the Component Development and Integration Facility (CDIF) in Butte, Montana will be performed, so that by the early 1990's, an engineering data base on the reliability, availability, maintainability and performance of the system will be available to allow scaleup of the prototypical designs to the next development level. This Sixteenth Quarterly Technical Progress Report covers the period May 1, 1991 to July 31, 1991.

  19. Externally fired combined cycle demonstration

    SciTech Connect

    Orozco, N.J.; Young, S.; LaHaye, P.G.; Strom-Olsen, J.; Seger, J.L.; Pickup, H.

    1995-11-01

    Externally Fired Combined Cycles (EFCCs) can increase the amount of electricity produced from ash bearing fuels up to 40%, with overall powerplant efficiencies in excess of 45%. Achieving such high efficiencies requires high temperature-high pressure air heaters capable of driving modern gas turbines from gas streams containing the products of coal combustion. A pilot plant has been constructed in Kennebunk, Maine to provide proof of concept and evaluation of system components. Tests using pulverized Western Pennsylvania bituminous coal have been carried out since April, 1995. The ceramic air heater extracts energy from the products of coal combustion to power a gas turbine. This air heater has operated at gas inlet temperatures over 1,095 C and pressures over 7.0 atm without damage to the ceramic tube string components. Stable gas turbine operation has been achieved with energy input from the air heater and a supplementary gas fired combustor. Efforts are underway to fire the cycle on coal only, and to increase the duration of the test runs. Air heater improvements are being implemented and evaluated. These improvements include installation of a second pass of ceramic tubes and evaluation of corrosion resistant coatings on the ceramic tubes.

  20. Qualification sous irradiation du crayon cea: de la conception des composants a l'irradiation d'assemblages en reacteur de puissance

    NASA Astrophysics Data System (ADS)

    Marin, Jean-François; Pillet, Claude; François, Bernard; Morize, Pierre; Petitgrand, Sylvie; Atabek, Rose-Marie; Houdaille, Brigitte

    1982-04-01

    Cet article résume les principaux résultats obtenus au CEA au cours des dix dernières années dans la conception, la qualification et la fabrication des différents éléments originaux constitutifs d'un assemblage de réacteur à eau pressurisée, notamment: l'oxyde UO 2 obtenu par le procédé du Double Cycle Inverse, la gaine en zircaloy 4 recris talllsée, la grille à ressort papillon, la structure à grilles coulissantes. Les etudes et essais hors-pile de comportement thermomécanique du crayon et thermohydraulique des composants de l'assemblage, les irradiations paramétriques de crayons jusqu'à une combustion massique élevée, la validation à partir d'examens aprés irradiation des principaux modèles introduits dans les calculs de conception, enfin l'introduction en réacteur prototype, puis en réacteur de puissance d'assemblages comportant ces différents éléments, constituent les principales étapes de ce développement.

  1. A model for life cycle records management

    SciTech Connect

    Tayfun, A.C.; Gibson, S.

    1996-10-01

    The primary objective of this paper is to update an old Records Management concept; the management of records according to the records life cycle. Accordingly, the authors are presenting a new version of the Records Management life cycle model and its associated elements. The basic concept is that every record progresses through three phases; a record is created, is used and maintained, and dispositioned. In this presentation, the authors update the very old straight line model and the more current circular model with a new model that essentially combines the two. The model portrays Records Management as having a distinct straight-line beginning, a circular use and maintenance phase, and a distinct straight-line end. The presentation maps Records Management Program elements and activities against the phases depicted in the model. The authors believe that this new records life cycle model is an enhanced physical representation of the process. This presentation is designed to help put all of the specialized Records Management topics that participants have heard about during the conference in the perspective of the records life cycle.

  2. A comparison of single-cycle versus multi-cycle proof testing strategies

    NASA Technical Reports Server (NTRS)

    Hudak, Stephen J., Jr.; Russell, Dale A.

    1988-01-01

    Proof testing was a useful supplement to conventional nondestructive evaluation (NDE) of space shuttle main engine (SSME) components. Since many of these components involve thin sections and high toughness materials, such as Inconel 718, conventional single-cycle proof test logic is not applicable due to the propensity for stable crack growth during the proof tests. Experience with five-cycle proof testing of SSME components is summarized and a framework is outlined for understanding multi-cycle proof testing using the fracture mechanics concept of a resistance curve. Extreme value statistics are also used to propose an empirical approach to compare the advantages and disadvantages of single- versus multi-cycle proof testing. The importance of the initial flaw size distribution and specimen thickness in such a comparison is also discussed.

  3. Etude de la transition tribologique entre le fretting et le meso-fretting pour des materiaux de contact electrique

    NASA Astrophysics Data System (ADS)

    Gagnon, Daniel

    Dans les installations electriques, les contacts sont toujours soumis a des contraintes alternees ou a des micro-deplacements. Il en resulte une corrosion par fretting, phenomene defini comme un type de deterioration de la surface qui se produit lorsque deux materiaux en contact sont soumis a des mouvements microscopiques d'oscillations de tres faible amplitude (0 a 100 mum). Ceci a pour effet de provoquer une degradation de la resistance de contact et une interruption du passage du courant. Ce phenomene a des repercussions considerables sur le plan pratique puisque les micro-deplacements de pieces en contact peuvent etre causes par la dilatation thermique differentielle des metaux, par des vibrations mecaniques, par la relaxation des contraintes ou par l'echauffement des contacts lorsqu'on interrompt et retablit le courant. Nous avons donc dans le cadre de cette these etudie plusieurs aspects du fretting (0--100 mum) et du meso-fretting (100 a 1000 mum) pour differents materiaux de contact electrique. Des travaux experimentaux ont ete realises a partir de deux montages reproduisant divers aspects de la degradation par le fretting. Un premier montage de fretting de type bille-plaque a ete entierement developpe a l'ETS et un second montage, de type fil-plaque a ete utilise en collaboration avec Hydro Quebec IREQ a Varennes. Plusieurs techniques de mesures et d'analyse relevant tant du domaine de la mecanique du contact que de la metallurgie ont ete utilisees pour traiter les resultats. L'influence du courant sur le taux d'usure et la force de friction a ete examinee pour divers materiaux de contacts. Des essais de fatigue thermique et electrique ont ete realises sur divers materiaux et lubrifiants de contact. Il a ete demontre que pour le domaine entre 100 mum et 1000 mum, le taux d'usure n'est pas le meme de 0 a 100 mum et au dela de 1000 mum. La plupart des materiaux evalues montrent un stade de comportement intermediaire dont le debut se situe entre 100 mum et

  4. Emerging SPS Concepts

    NASA Technical Reports Server (NTRS)

    Hanley, G.; Woodcock, G. R.

    1980-01-01

    Four technologies were evaluated to determine their effect on Satellite Power System concepts. Two of these technologies, solid-state power amplifiers and magnetrons, are replacements for the Klystrons used for dc to RF conversion on the satellite. A third technology, laser power transmission, transmits the energy at laser frequencies rather than microwave frequencies. The fourth technology, multibandgap solar cells, has the promise of significantly increased solar to dc conversion efficienty as compared to the reference-concept silicon and gallium arsenide solar cells. The design characteristics of concepts resulting from application of these technologies are summarized.

  5. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  6. Blazars: Artist Conception

    NASA Video Gallery

    What astronomers once thought were two blazar families may in fact be one, as shown in this artist's concept. Energy stored in the black hole during its salad days of intense accretion may later be...

  7. Common tester platform concept.

    SciTech Connect

    Hurst, Michael James

    2008-05-01

    This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

  8. Decoding Astronomical Concepts

    ERIC Educational Resources Information Center

    Durisen, Richard H.; Pilachowski, Catherine A.

    2004-01-01

    Two astronomy professors, using the Decoding the Disciplines process, help their students use abstract theories to analyze light and to visualize the enormous scale of astronomical concepts. (Contains 5 figures.)

  9. Synthesis of a BSA-Le(x) glycoconjugate and recognition of Le(x) analogues by the anti-Le(x) monoclonal antibody SH1: the identification of a non-cross reactive analogue.

    PubMed

    Wang, Jo-Wen; Asnani, Ari; Auzanneau, France-Isabelle

    2010-10-15

    A Le(x) trisaccharide functionalized with a cysteamine arm was prepared and this synthesis provided additional information on the reactivity of N-acetylglucosamine O-4 acceptors when they are glycosylated with trichloroacetimidate donors activated with excess BF(3)·OEt(2). In turn, this trisaccharide was conjugated to BSA lysine side chains through a squarate-mediated coupling. This BSA-Le(x) glycoconjugate displayed 35 Le(x) haptens per BSA molecule. The relative affinity of the anti-Le(x) monoclonal antibody SH1 for the Le(x) antigen and analogues of Le(x) in which the D-glucosamine, L-fucose or D-galactose residues were replaced with D-glucose, L-rhamnose and D-glucose, respectively, was measured by competitive ELISA experiments. While all analogues were weaker inhibitors than the Le(x) antigen, only the analogue of Le(x) in which the galactose residue was replaced by a glucose unit showed no binding to the SH1 mAb. To confirm that the reduced or loss of recognition of the Le(x) analogues by the anti-Le(x) mAb SH1 did not result from different conformations adopted by the analogues when compared to the native Le(x) antigen, we assessed the conformational behavior of all trisaccharides by a combination of stochastic searches and NMR experiments. Our results showed that, indeed, the analogues adopted the same stacked conformation as that identified for the Le(x) antigen. The identification of a trisaccharide analogue that does not cross-react with Le(x) but still retains the same conformation as Le(x) constitutes the first step to the design of a safe anti-cancer vaccine based on the dimeric Le(x) tumor associated carbohydrate antigen.

  10. Conception, instrumentation, modelisation et analyse d'un element de stockage d'energie par chaleur latente

    NASA Astrophysics Data System (ADS)

    Millette, Jocelyn

    Des elements de stockage de chaleur utilisant l'electricite comme source d'energie sont utilises presentement en Europe ou la tarification de l'electricite varie en fonction du temps. Dans un contexte ou la dereglementation du marche de l'electricite s'opere massivement en Amerique du Nord, ce type d'appareil est susceptible d'etre beaucoup plus utilise afin de faire une gestion efficace de la consommation electrique. En assurant un meilleur facteur d'utilisation des installations de production, transport et distribution, les utilites pourront etre plus competitives. Les appareils disponibles sur le marche stockent l'energie sous forme sensible (ESECS), ce qui amene differents inconvenients: poids considerable, temperature elevee. Un nouveau type d'appareil est propose dans cette etude: un element de stockage d'energie par chaleur latente (ESECL). Cette etude traite donc de la conception de tels appareils. La demarche de conception proposee dans cette etude s'articule autour du choix des materiaux, du choix du concept de l'echangeur de chaleur. A ce sujet, les materiaux a changement de phase (MCP) etant generalement de mauvais conducteur thermique sous forme solide, la surface d'echange doit etre grande afin d'obtenir une puissance de destockage convenable. Le concept retenu est un element multicouches. D'apres la revue de litterature, la conception d'un element de stockage multicouches par chaleur latente n'a jamais ete abordee. Afin de pouvoir calculer les performances d'un ESECL a construire, un modele NTU-epsilon a ete developpe a cette fin. Contrairement. a ce qui est reporte dans la litterature, le modele developpe tient compte de la surchauffe et de la chaleur sensible dans le MCP solide. Afin d'etablir le modele, la convection naturelle dans le MCP liquide est negligee et un regime quasi permanent est considere dans le MCP. Un prototype d'ESECL a ete construit et instrumente dans le but d'eprouver la demarche de conception et de valider le modele developpe

  11. Transitions de phase dans le oxyde de yttrium vanadium

    NASA Astrophysics Data System (ADS)

    Roberge, Benoit

    Dans le mémoire qui suit, les ordres structural, magnétiques et orbital dans le YVO3 sont étudiés avec l'aide de la diffraction des rayons X,de la spectroscopie Raman et de la technique de la cavité résonnante hyperfréquence. L'objectif premier consiste à observer l'évolution de ces ordres en fonction de la température. Le mémoire met ensuite en évidence le couplage entre les différents ordres cohabitants dans le YVO3 . Les mesures effectuées par la diffraction des rayons X permettent de mesurer le caractère polycrystallin des échantillons du YVO 3. Une comparaison de nos mesures avec des mesures de diffraction des rayons X faites sur la poudre de YVO3 indique la faible présence de maclage. Les mesures effectuées avec la technique de résonnance hyperfréquence permettent de suivre l'évolution de la constante diélectrique en fonction de la température. Les changements impliquant l'ordre orbital se manifestent de manière évidente dans la constante diélectrique à 200 K et à 77 K. La transition diélectrique détectée à 77 K est une transition de premier ordre. Un couplage entre les propriétés diélectriques et magnétiques est observable à la température de Néel à 114 K. L'effet d'un champ magnétique fixe sur la température de transition de l'ordre orbital survenant à 77 K est également remarquable. Cela indique un couplage magnétodiélectrique démontrant ainsi le caractère multiferroïque du YVO 3. Finalement, l'observation d'un mécanisme de relaxation pouvant être modélisé par le modèle d'Havriliak-Negami est observé en dessous de 77 K. En utilisant le modèle d'Arrhénius et le modèle d'Havriliak-Negami, on peut caractériser le mécanisme avec son énergie d'activation et son temps de relaxation. Les mesures effectuées en spectroscopie Raman permettent de suivre l'évolution de la structure du YVO3 en fonction de la température. Les deux changements structuraux survenant à 200 K et 77 K sont observés. Le

  12. Two Quantum Polytropic Cycles

    NASA Astrophysics Data System (ADS)

    Arias-Hernández, L. A.; Morales-Serrano, A. F.

    2002-11-01

    In this work we follow the Bender et al paper [1] to study the quantum analogues of the Stirling and Ericsson polytropic cycles. In the context of the classical thermodynamics, the Stirling and Ericsson cycles correspond to reversible heat engines with two isothermal processes joined by two polytropic branches which occur in a device called regenerator. If this device is an ideal one, the efficiency of these cycles is the Carnot efficiency. Here, we introduce the quantum analogues of the Stirling and Ericsson cycles, the first one based on a double square potential well with a finite potential barrier, since in this system the tunnel effect could be the analogue to the regeneration classical process, therefore the isochoric quantum branches would really correspond to an internal energy storage, and the last one with an unknown system where the isobaric quantum processes don't induce changes in its quantum state. With these systems the quantum engines have cycles consisting of polytropic and isothermal quantum processes analogues to the corresponding classical processes. We show that in both cases the quantum cycles have an efficiency given by ηCQM = 1 - EC/EH, which is the same expression for the quantum analogue of the Carnot cycle studied by Bender.

  13. The AERA Concept.

    DTIC Science & Technology

    1981-03-24

    electrgnic tabular displays ( ETABS ). - , This concept document was prepared by a team of ATC experts to review prior work, the on-going AERA program, and to...Address Beacon System (DABS), trajectory modeling and planning algorithms, and electronic tabular displays ( ETABS ). This concept document was...capability, and a Flight Management System. The development of AERA requires major efforts in system design and software and man-machine interface

  14. Concept analysis: resilience.

    PubMed

    Garcia-Dia, Mary Joy; DiNapoli, Jean Marie; Garcia-Ona, Leila; Jakubowski, Rita; O'Flaherty, Deirdre

    2013-12-01

    This paper will systematically analyze the concept of resilience using an integrated review of literature. The historical perspective, attributes, antecedents, and consequences of resilience will be reviewed. A theoretical and operational definition will be provided. The Walker and Avant method will be used to describe the cases. Finally, the use of concept map will capture the relationships among the attributes, antecedents, consequences, and empirical indicators through clustering and chaining.

  15. Le Chatelier's principle in sensation and perception: fractal-like enfolding at different scales.

    PubMed

    Norwich, Kenneth H

    2010-01-01

    Le Chatelier's principle asserts that a disturbance, when applied to a resting system may drive the system away from its equilibrium state, but will invoke a countervailing influence that will counteract the effect of the disturbance. When applied to the field of sensation and perception, a generalized stimulus will displace the system from equilibrium, and a generalized adaptation process will serve as the countervailing influence tending to reduce the impact of the stimulus. The principle applies at all levels, from the behavioral to the neural, the larger enfolding the smaller in fractal-like form. Le Chatelier's principle, so applied, leads to the unification of many concepts in sensory science. Ideas as diverse as sensory adaptation, reflex arcs, and simple deductive logic can be brought under the umbrella of a single orienting principle. Beyond unification, this principle allows us to approach many questions in pathophysiology from a different perspective. For example, we find new direction toward the reduction of phantom-limb pain and possibly of vertigo.

  16. Applied physiology of cycling.

    PubMed

    Faria, I E

    1984-01-01

    Historically, the bicycle has evolved through the stages of a machine for efficient human transportation, a toy for children, a finely-tuned racing machine, and a tool for physical fitness development, maintenance and testing. Recently, major strides have been made in the aerodynamic design of the bicycle. These innovations have resulted in new land speed records for human powered machines. Performance in cycling is affected by a variety of factors, including aerobic and anaerobic capacity, muscular strength and endurance, and body composition. Bicycle races range from a 200m sprint to approximately 5000km. This vast range of competitive racing requires special attention to the principle of specificity of training. The physiological demands of cycling have been examined through the use of bicycle ergometers, rollers, cycling trainers, treadmill cycling, high speed photography, computer graphics, strain gauges, electromyography, wind tunnels, muscle biopsy, and body composition analysis. These techniques have been useful in providing definitive data for the development of a work/performance profile of the cyclist. Research evidence strongly suggests that when measuring the cyclist's aerobic or anaerobic capacity, a cycling protocol employing a high pedalling rpm should be used. The research bicycle should be modified to resemble a racing bicycle and the cyclist should wear cycling shoes. Prolonged cycling requires special nutritional considerations. Ingestion of carbohydrates, in solid form and carefully timed, influences performance. Caffeine appears to enhance lipid metabolism. Injuries, particularly knee problems which are prevalent among cyclists, may be avoided through the use of proper gearing and orthotics. Air pollution has been shown to impair physical performance. When pollution levels are high, training should be altered or curtailed. Effective training programmes simulate competitive conditions. Short and long interval training, blended with long

  17. [Comfort: a concept analysis].

    PubMed

    Tsai, Jia-Ling; Lee, Ya-Ling; Hu, Wen-Yu

    2012-02-01

    Comfort is an important concept and core value of nursing. The defining attributes, antecedents and consequences of comfort need further analysis and exploration, even though the concept of comfort has been addressed previously in nursing literature. We employed the strategies of concept analysis as described by Walker&Avant (2005) to analyze the concept of comfort. The defining attributes of comfort include: 1) effective communication; 2) family and meaningful relationships; 3) maintaining functionality; 4) self-characteristics; 5) physical symptom relief, states, and interventions; 6) psychological, spiritual activities and states; and 7) a sense of safety and security. Antecedents consist of discomfort, distress and suffering. Consequences consist of (1) met/satisfied needs; (2) increased sense of control; (3) sense of inner peace; (4) a pleasant experience; (5) feeling cared for; (6) relief of symptoms; (7) reduced suffering; (8) decreased disequilibrium; and (9) absence of discomfort. We also outline the construction of cases, empirical references and comfort measurement tools. Analysis found comfort to have multiple dimensions and confirmed it as a clinical issue that should receive greater emphasis and valuation. Findings are hoped to increase nurse understanding of the concept of comfort and enable nurses to evaluate level of comfort and follow up on variations in such using empirical tools. Concept analysis can guide further comfort related interventions and research to benefit patients.

  18. [Mindfulness: A Concept Analysis].

    PubMed

    Chen, Tsai-Ling; Chou, Fan-Hao; Wang, Hsiu-Hung

    2016-04-01

    "Mindfulness" is an emerging concept in the field of healthcare. Ranging from stress relief to psychotherapy, mindfulness has been confirmed to be an effective tool to help individuals manage depression, anxiety, obsessive-compulsive disorder, and other health problems in clinical settings. Scholars currently use various definitions for mindfulness. While some of these definitions overlap, significant differences remain and a general scholarly consensus has yet to be reached. Several domestic and international studies have explored mindfulness-related interventions and their effectiveness. However, the majority of these studies have focused on the fields of clinical medicine, consultation, and education. Mindfulness has rarely been applied in clinical nursing practice and no related systematic concept analysis has been conducted. This paper conducts a concept analysis of mindfulness using the concept analysis method proposed by Walker and Avant (2011). We describe the defining characteristics of mindfulness, clarify the concept, and confirm the predisposing factors and effects of mindfulness using examples of typical cases, borderline cases, related cases, and contrary case. Findings may provide nursing staff with an understanding of the concept of mindfulness for use in clinical practice in order to help patients achieve a comfortable state of body and mind healing.

  19. When Marcel Mauss's Essai sur le Don becomes The Gift: variations on the theme of solidarity.

    PubMed

    Bateman, Simone

    2016-12-01

    Since the early 1970s, Marcel Mauss's Essai sur le Don (1923), translated into English as The Gift in 1954, has been a standard reference in the social science and bioethical literature on the use of human body parts and substances for medical and research purposes. At that time, three social scientists-political scientist Richard Titmuss in the United Kingdom and sociologist Renée C. Fox working with historian Judith Swazey in the United States-had the idea of using this concept to highlight the fundamental structure of the biomedical practices they were studying, respectively, blood donation, and hemodialysis and organ transplantation. The fact that these first applications of Mauss's essay should emerge in English- rather than in French-speaking countries raises the question of what the translation of the essay, and notably of the word don as gift, may have to do with this fact. Reading Mauss in translation undoubtedly inspired a seminal approach to interpreting medical and research practices based on bodily giving. This article posits that something may have also been lost: a much broader concept of giving with unquestionable links to the Durkheimian concept of solidarity, which Mauss conceptualizes not only as an obligation but also as a liberty to give.

  20. Food and medical sample freezer kit concept for Shuttle

    NASA Technical Reports Server (NTRS)

    Copeland, R. J.; Jaax, J. R.; Proctor, B. W.

    1977-01-01

    A variety of food and storage of samples can be provided by a Space Shuttle Orbiter Freezer Kit. The proposed concept is an integrated package consisting of four -23 C (-10 F) storage compartments and a Stirling cycle refrigeration unit. The Stirling cycle mechanical refrigeration was selected over alternative systems for superior efficiency and safety. The trade-offs and a conceptual design of the system are presented.

  1. Cycle isolation monitoring

    SciTech Connect

    Svensen, L.M. III; Zeigler, J.R.; Todd, F.D.; Alder, G.C.

    2009-07-15

    There are many factors to monitor in power plants, but one that is frequently overlooked is cycle isolation. Often this is an area where plant personnel can find 'low hanging fruit' with great return on investment, especially high energy valve leakage. This type of leakage leads to increased heat rate, potential valve damage and lost generation. The fundamental question to ask is 'What is 100 Btu/kW-hr of heat rate worth to your plant? On a 600 MW coal-fired power plant, a 1% leakage can lead to an 81 Btu/kW-hr impact on the main steam cycle and a 64 Btu/kW-hr impact on the hot reheat cycle. The article gives advice on methods to assist in detecting leaking valves and to monitor cycle isolation. A software product, TP. Plus-CIM was designed to estimate flow rates of potentially leaking valves.

  2. Mining the Learning Cycle.

    ERIC Educational Resources Information Center

    Hemler, Debra; King, Hobart

    1996-01-01

    Describes an approach that uses the learning cycle to meaningfully teach students about mineral properties while alleviating the tedious nature of identifying mineral specimens. Discusses mineral properties, cooperative learning, and mineral identification. (JRH)

  3. The Rock Cycle

    ERIC Educational Resources Information Center

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  4. Solar Cycle Prediction.

    PubMed

    Petrovay, Kristóf

    A review of solar cycle prediction methods and their performance is given, including forecasts for cycle 24. The review focuses on those aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is further restricted to the issue of predicting the amplitude (and optionally the epoch) of an upcoming solar maximum no later than right after the start of the given cycle. Prediction methods form three main groups. Precursor methods rely on the value of some measure of solar activity or magnetism at a specified time to predict the amplitude of the following solar maximum. Their implicit assumption is that each numbered solar cycle is a consistent unit in itself, while solar activity seems to consist of a series of much less tightly intercorrelated individual cycles. Extrapolation methods, in contrast, are based on the premise that the physical process giving rise to the sunspot number record is statistically homogeneous, i.e., the mathematical regularities underlying its variations are the same at any point of time and, therefore, it lends itself to analysis and forecasting by time series methods. Finally, instead of an analysis of observational data alone, model based predictions use physically (more or less) consistent dynamo models in their attempts to predict solar activity. In their overall performance during the course of the last few solar cycles, precursor methods have clearly been superior to extrapolation methods. Nevertheless, most precursor methods overpredicted cycle 23, while some extrapolation methods may still be worth further study. Model based forecasts have not yet had a chance to prove their skills. One method that has yielded predictions consistently in the right range during the past few solar cycles is that of K. Schatten et al., whose approach is mainly based on the polar field precursor. The incipient cycle 24 will probably mark the end of the Modern Maximum, with the Sun switching to a state of

  5. Inhomogeneites dans le Vent des Etoiles Wolf-Rayet

    NASA Astrophysics Data System (ADS)

    Robert, Carmelle

    1992-01-01

    Des mesures spectroscopiques effectuees avec un haut rapport signal sur bruit et une bonne resolution ont demontre l'existence de regions perturbees en mouvement dans le vent d'etoiles Wolf-Rayet (WR). L'echantillon d'objets etudies ici comprend 9 etoiles WR couvrant differents sous-types WN et WC. De nombreuses petites structures variables superposees au profil des raies d'emission formees dans le vent stellaire signalent la presence des perturbations. L'etude des variations globales des raies et l'examen des micro-structures individuelles ont permis de decrire plusieurs caracteristiques des perturbations. Entre autres, on observe des correlations significatives entre le niveau de variabilite des raies et certains parametres des etoiles qui confirment que le phenomene de variabilite est intrinseque au vent stellaire. En comparant les changements des vitesses radiales et des largeurs equivalentes des differentes raies d'une meme etoile, on conclut que les regions perturbees ont une etendue finie par rapport a l'enveloppe des etoiles. On peut facilement suivre les structures individuelles sur une periode de temps couvrant ~eq8 heures (et peut etre meme 24 heures) avant qu'elles ne disparaissent. Durant ce temps les structures se deplacent en s'eloignant du centre de la raie. A partir des differents comportements notes lors de l'analyse des variations globales et lors de l'examen des structures individuelles, on propose de representer les perturbations par un modele d'inhomogeneites discretes en expansion dans le vent. On suppose simplement que les inhomogeneites emettent comme le vent global (et absorbent aussi si le vent global montre un profil P Cyg). La superposition du graphique de l'acceleration radiale moyenne des inhomogeneites de WR140 en fonction de leur vitesse radiale et du modele theorique d'inhomogeneites qui suivent la loi generale de vitesse donne un taux d'acceleration lent, avec beta >= 3 pour les inhomogeneites de cette etoile. On obtient, entre

  6. Concepts For An EO Land Convoy Mission

    NASA Astrophysics Data System (ADS)

    Cutter, M. A.; Eves, S.; Remedios, J.; Humpage, N.; Hall, D.; Regan, A.

    2013-12-01

    ESA are undertaking three studies investigating possible synergistic satellite missions flying in formation with the operational Copernicus Sentinel missions and/or the METOP satellites. These three studies are focussed on:- a) ocean and ice b) land c) atmosphere Surrey Satellite Technology Ltd (SSTL), the University of Leicester and Astrium Ltd are undertaking the second of these studies into the synergetic observation by missions flying in formation with European operational missions, focusing on the land theme. The aim of the study is to identify and develop, (through systematic analysis), potential innovative Earth science objectives and novel applications and services that could be made possible by flying additional satellites, (possibly of small-class type), in constellation or formation with one or more already deployed or firmly planned European operational missions, with an emphasis on the Sentinel missions, but without excluding other possibilities. In the long-term, the project aims at stimulating the development of novel, (smaller), mission concepts in Europe that may exploit new and existing European operational capacity in order to address in a cost effective manner new scientific objectives and applications. One possible route of exploitation would be via the proposed Small Mission Initiative (SMI) that may be initiated under the ESA Earth Explorer Observation Programme (EOEP). The following ESA science priority areas have been highlighted during the study [1]:- - The water cycle - The carbon cycle - Terrestrial ecosystems - Biodiversity - Land use and land use cover - Human population dynamics The study team have identified the science gaps that might be addressed by a "convoy" mission flying with the Copernicus Sentinel satellites, identified the candidate mission concepts and provided recommendations regarding the most promising concepts from a list of candidates. These recommendations provided the basis of a selection process performed by ESA

  7. Diurnal Cycle Computations

    SciTech Connect

    Covey, Curt; Doutriaux, Charles

    2016-12-01

    Directory /export_backup/covey1/CMIP5/Precipitation/DiurnalCycle/GridpointTimeseries/CMCCBCM_etal/ on crunchy.llnl.gov contains Python / UV-CDAT scripts compositeDiurnalStatistics.py and fourierDiurB nalAllGrid.py. compositeDiurnalStatistics.py reads high-time-frequency climate data from one or more years and computes 24 hour composite-mean and composite-standard-deviation cycles for one requested month.

  8. Quantifying the adaptive cycle

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  9. Solar Cycle Predictions

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean

    2012-01-01

    Solar cycle predictions are needed to plan long-term space missions; just like weather predictions are needed to plan the launch. Fleets of satellites circle the Earth collecting many types of science data, protecting astronauts, and relaying information. All of these satellites are sensitive at some level to solar cycle effects. Predictions of drag on LEO spacecraft are one of the most important. Launching a satellite with less propellant can mean a higher orbit, but unanticipated solar activity and increased drag can make that a Pyrrhic victory as you consume the reduced propellant load more rapidly. Energetic events at the Sun can produce crippling radiation storms that endanger all assets in space. Solar cycle predictions also anticipate the shortwave emissions that cause degradation of solar panels. Testing solar dynamo theories by quantitative predictions of what will happen in 5-20 years is the next arena for solar cycle predictions. A summary and analysis of 75 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. The current state of solar cycle predictions and some anticipations how those predictions could be made more accurate in the future will be discussed.

  10. Quantifying the Adaptive Cycle.

    PubMed

    Angeler, David G; Allen, Craig R; Garmestani, Ahjond S; Gunderson, Lance H; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  11. Observing the Global Water Cycle from Space

    NASA Technical Reports Server (NTRS)

    Hildebrand, Peter H.; Houser, Paul; Schlosser, C. Adam

    2003-01-01

    This paper presents an approach to measuring all major components of the water cycle from space. The goal of the paper is to explore the concept of using a sensor-web of satellites to observe the global water cycle. The details of the required measurements and observation systems are therefore only an initial approach and will undergo future refinement, as their details will be highly important. Key elements include observation and evaluation of all components of the water cycle in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers-and in terms of the global fluxes of water between these reservoirs. For each component of the water cycle that must be observed, the appropriate temporal and spatial scales of measurement are estimated, along with the some of the frequencies that have been used for active and passive microwave observations of the quantities. The suggested types of microwave observations are based on the heritage for such measurements, and some aspects of the recent heritage of these measurement algorithms are listed. The observational requirements are based on present observational systems, as modified by expectations for future needs. Approaches to the development of space systems for measuring the global water cycle can be based on these observational requirements.

  12. Venus Altitude Cycling Balloon

    NASA Astrophysics Data System (ADS)

    de Jong, M. L.

    2015-04-01

    A novel balloon concept is demonstrated that uses mechanical compression as altitude control mechanism to sustain long duration balloon probe flight in the cloud level region of Venus’ atmosphere between 45 and 58 km altitude.

  13. LIFE CYCLE ENGINEERING GUIDELINES

    EPA Science Inventory

    This document provides guidelines for the implementation of LCE concepts, information, and techniques in engineering products, systems, processes, and facilities. To make this document as practical and useable as possible, a unifying LCE framework is presented. Subsequent topics ...

  14. A Key Concept: Spatial Organization

    ERIC Educational Resources Information Center

    Kostrowicki, Jerzy

    1975-01-01

    The application of geography to spatial planning is discussed. Concepts presented include the regional concept, the typological concept, and spatial structure, spatial processes, and spatial organization. For address of journal see SO 504 028. (Author/RM)

  15. Innovative Airbreathing Propulsion Concepts for Access to Space

    NASA Technical Reports Server (NTRS)

    Whitlow, Jr., Woodrow; Blech, Richard A.; Blankson, Isaiah M.

    2001-01-01

    This paper will present technologies and concepts for novel aeropropulsion systems. These technologies will enhance the safety of operations, reduce life cycle costs, and contribute to reduced costs of air travel and access to space. One of the goals of the NASA program is to reduce the carbon-dioxide emissions of aircraft engines. Engine concepts that use highly efficient fuel cell/electric drive technologies in hydrogen-fueled engines will be presented in the proposed paper. Carbon-dioxide emissions will be eliminated by replacing hydrocarbon fuel with hydrogen, and reduce NOx emissions through better combustion process control. A revolutionary exoskeletal engine concept, in which the engine drum is rotated, will be shown. This concept has the potential to allow a propulsion system that can be used for subsonic through hypersonic flight. Dual fan concepts that have ultra-high bypass ratios, low noise, and low drag will be presented. Flow-controlled turbofans and control-configured turbofans also will be discussed. To increase efficiency, a system of microengines distributed along lifting surfaces and on the fuselage is being investigated. This concept will be presented in the paper. Small propulsion systems for affordable, safe personal transportation vehicles will be discussed. These low-oil/oilless systems use technologies that enable significant cost and weight reductions. Pulse detonation engine-based hybrid-cycle and combined-cycle propulsion systems for aviation and space access will be presented.

  16. Concept Analysis: Music Therapy.

    PubMed

    Murrock, Carolyn J; Bekhet, Abir K

    2016-01-01

    Down through the ages, music has been universally valued for its therapeutic properties based on the psychological and physiological responses in humans. However, the underlying mechanisms of the psychological and physiological responses to music have been poorly identified and defined. Without clarification, a concept can be misused, thereby diminishing its importance for application to nursing research and practice. The purpose of this article was for the clarification of the concept of music therapy based on Walker and Avant's concept analysis strategy. A review of recent nursing and health-related literature covering the years 2007-2014 was performed on the concepts of music, music therapy, preferred music, and individualized music. As a result of the search, the attributes, antecedents, and consequences of music therapy were identified, defined, and used to develop a conceptual model of music therapy. The conceptual model of music therapy provides direction for developing music interventions for nursing research and practice to be tested in various settings to improve various patient outcomes. Based on Walker and Avant's concept analysis strategy, model and contrary cases are included. Implications for future nursing research and practice to use the psychological and physiological responses to music therapy are discussed.

  17. Space vehicle concepts

    NASA Technical Reports Server (NTRS)

    Tucker, Michael; Meredith, Oliver; Brothers, Bobby

    1986-01-01

    Several concepts of chemical-propulsion Space Vehicles (SVs) for manned Mars landing missions are presented. For vehicle sizing purposes, several specific missions were chosen from opportunities in the late 1990's and early 2000's, and a vehicle system concept is then described which is applicable to the full range of missions and opportunities available. In general, missions utilizing planetary opposition alignments can be done with smaller vehicles than those utilizing planetary opposition alignments. The conjunction missions have a total mission time of about 3 years, including a required stay-time of about 60 days. Both types of missions might be desirable during a Mars program, the opposition type for early low-risk missions and/or for later unmanned cargo missions, and the conjunction type for more extensive science/exploration missions and/or for Mars base activities. Since the opposition missions appeared to drive the SV size more severely, there were probably more cases examined for them. Some of the concepts presented utilize all-propulsive braking, some utilize and all aerobraking approach, and some are hybrids. Weight statements are provided for various cases. Most of the work was done on 0-g vehicle concepts, but partial-g and 1-g concepts are also provided and discussed. Several options for habitable elements are shown, such as large-diameter modules and space station (SS) types of modules.

  18. Creating Heliophysics Concept Maps

    NASA Astrophysics Data System (ADS)

    Ali, N. A.; Peticolas, L. M.; Paglierani, R.; Mendez, B. J.

    2011-12-01

    The Center for Science Education at University of California Berkeley's Space Sciences Laboratory is creating concept maps for Heliophysics and would like to get input from scientists. The purpose of this effort is to identify key concepts related to Heliophysics and map their progression to show how students' understanding of Heliophysics might develop from Kindergarten through higher education. These maps are meant to tie into the AAAS Project 2061 Benchmarks for Scientific Literacy and National Science Education Standards. It is hoped that the results of this effort will be useful for curriculum designers developing Heliophysics-related curriculum materials and classroom teachers using Heliophysics materials. The need for concept maps was identified as a result of product analysis undertaken by the NASA Heliophysics Forum Team. The NASA Science Education and Public Outreach Forums have as two of their goals to improve the characterization of the contents of the Science Mission Directorate and Public Outreach (SMD E/PO) portfolio (Objective 2.1) and assist SMD in addressing gaps in the portfolio of SMD E/PO products and project activities (Objective 2.2). An important part of this effort is receiving feedback from solar scientists regarding the inclusion of key concepts and their progression in the maps. This session will introduce the draft concept maps and elicit feedback from scientists.

  19. Investigation of Exoskeletal Engine Propulsion System Concept

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Palac, Donald T.; Hunter, James E.; Myers, David E.; Snyder, Christopher A.; Kosareo, Daniel N.; McCurdy, David R.; Dougherty, Kevin T.

    2005-01-01

    An innovative approach to gas turbine design involves mounting compressor and turbine blades to an outer rotating shell. Designated the exoskeletal engine, compression (preferable to tension for high-temperature ceramic materials, generally) becomes the dominant blade force. Exoskeletal engine feasibility lies in the structural and mechanical design (as opposed to cycle or aerothermodynamic design), so this study focused on the development and assessment of a structural-mechanical exoskeletal concept using the Rolls-Royce AE3007 regional airliner all-axial turbofan as a baseline. The effort was further limited to the definition of an exoskeletal high-pressure spool concept, where the major structural and thermal challenges are represented. The mass of the high-pressure spool was calculated and compared with the mass of AE3007 engine components. It was found that the exoskeletal engine rotating components can be significantly lighter than the rotating components of a conventional engine. However, bearing technology development is required, since the mass of existing bearing systems would exceed rotating machinery mass savings. It is recommended that once bearing technology is sufficiently advanced, a "clean sheet" preliminary design of an exoskeletal system be accomplished to better quantify the potential for the exoskeletal concept to deliver benefits in mass, structural efficiency, and cycle design flexibility.

  20. Development of characteristic evaluation method on FR cycle system

    SciTech Connect

    Shinoda, Y.; Shiotani, H.; Hirao, K.

    2002-07-01

    The present report is intended to explain some results of the characteristic evaluation work on various FR cycle system concepts, in the 1. phase of the JNC's 'Feasibility Study on Commercialized Fast Reactor Cycle System' (from 1999 to March 2001). The development of the evaluation method is carried out for six criteria, such as Economics, Effective utilization of uranium resource, Reduction of environmental impact, Safety, Proliferation resistance, and Technological feasibility. (authors)

  1. Le risque de détresse morale dans la pratique contemporaine des soins de santé.

    PubMed

    Austin, Wendy

    2016-05-01

    Les professionnels de la santé sont des agents moraux dont la relation fiduciaire avec le public est animée par la responsabilité et la promesse de puiser dans leurs connaissances et leurs habiletés pour aider les personnes sous leurs soins. Lorsque leur capacité à tenir cette promesse est freinée ou compromise, ils risquent de souffrir de détresse morale. Le concept de détresse morale est défini et mis en contexte dans le milieu de la santé. Les contraintes et les facteurs qui en sont à l'origine sont présentés, de même que les moyens utilisés par les professionnels de la santé et les organisations de santé pour la soulager. Un changement transformateur s'impose pour vaincre la culture du silence et maintenir un système de santé où il est possible de vivre avec sa conscience.

  2. Menstruation and the Menstrual Cycle

    MedlinePlus

    ... Menstruation and the menstrual cycle Menstruation and the menstrual cycle > A-Z Health Topics Want help teaching your ... email updates Enter email Submit Menstruation and the menstrual cycle Menstruation is a woman's monthly bleeding. When you ...

  3. The concept of compartmentalisation.

    PubMed

    Scott, A; Zepeda, C; Garber, L; Smith, J; Swayne, D; Rhorer, A; Kellar, J; Shimshony, A; Batho, H; Caporale, V; Giovannini, A

    2006-12-01

    The rationale for establishing trade 'regions' and 'zones' is based on principles of epidemiological science and risk analysis that assess and manage animal disease risks so that the safety of trade can be ensured. However, the boundaries of geographical regions and zones may readily be breached through numerous epidemiological pathways. The concept of a 'compartment' extends the application of a 'risk boundary' beyond that of a geographical interface and considers all epidemiological factors that can contribute to the creation of an effective boundary. The fundamental requirement for application of either concept (regions/zones or compartments) is that the population considered for trade is maintained within management or geographical boundaries which allow clear epidemiological differentiation to be made between those animals and surrounding populations of higher risk. Seven factors are presented that an exporting country might use to guide the identification and documentation of a compartment. Additionally, the steps that would be undertaken to implement trade based on the compartmentalisation concept are discussed.

  4. New Mars vehicle concepts

    NASA Astrophysics Data System (ADS)

    Sherwood, Brent

    1993-02-01

    The paper briefly reviews the evolution of the Mars vehicle design concepts from 1952 to 1990, and the currently understood requirements, constraints, and options for manned Mars missions in the early decades of the 21st century. The most up-to-date integrated Mars vehicle concepts for crew-carrying transfer and excursion vehicles are presented together with the Mars descent-ascent mission phases. Particular attention is given to a reusable transfer ship, which is a modular vehicle launched to earth orbit on six 185 t-class boosters and assembled there robotically; it uses dual nuclear-thermal rocket engines and liquid hydrogen propellant. The lander concept is capable of supporting many kinds of surface missions anywhere on Mars.

  5. [Appraisal: a concept analysis].

    PubMed

    Kuo, Chia-Chi; Lin, Chiu-Chu; Ma, Shu-Ching

    2007-04-01

    Appraisal is a cognitive response by an individual facing an event within a given environment. When the individual has passed through a thought process that gives the event meaning, the coping process is finally completed. Coping heightens an individual's well-being. Negative appraisal will induce an emotional coping response and affect one's quality of life, mental state and health. Several researchers applied the concept of appraisal to their disciplines. The concept of appraisal, however, is poorly defined. This article applies the methodology outlined by Walker and Avant (1995) to analyze the concept of appraisal. The definition of appraisal, examples, and empirical references provided in this paper will be useful in nursing practice in relation to the role of appraisal in coping.

  6. Telepresence work system concepts

    NASA Technical Reports Server (NTRS)

    Jenkins, L. M.

    1985-01-01

    Telepresence has been used in the context of the ultimate in remote manipulation where the operator is provided with the sensory feedback and control to perform highly dexterous tasks. The concept of a Telepresence Work Station (TWS) for operation in space is described. System requirements, concepts, and a development approach are discussed. The TWS has the potential for application on the Space Shuttle, on the Orbit Maneuver Vehicle, on an Orbit Transfer Vehicle, and on the Space Station. The TWS function is to perform satellite servicing tasks and construction and assembly operations in the buildup of large spacecraft. The basic concept is a pair of dexterous arms controlled from a remote station by an operation with feedback. It may be evolved through levels of supervisory control to a smart adaptive robotic system.

  7. Robust Rocket Engine Concept

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.

    1995-01-01

    The potential for a revolutionary step in the durability of reusable rocket engines is made possible by the combination of several emerging technologies. The recent creation and analytical demonstration of life extending (or damage mitigating) control technology enables rapid rocket engine transients with minimum fatigue and creep damage. This technology has been further enhanced by the formulation of very simple but conservative continuum damage models. These new ideas when combined with recent advances in multidisciplinary optimization provide the potential for a large (revolutionary) step in reusable rocket engine durability. This concept has been named the robust rocket engine concept (RREC) and is the basic contribution of this paper. The concept also includes consideration of design innovations to minimize critical point damage.

  8. Le syndrome des enfants battus: aspects cliniques et radiologiques

    PubMed Central

    Jlalia, Zied; Znaigui, Talel; Smida, Mahmoud

    2016-01-01

    La maltraitance physique des enfants ou le syndrome des enfants battus est responsable de plus de 75.000 décès par an en France. Ce problème de santé publique reste sous diagnostiqué en Tunisie et dans le monde. Le chemin a été laborieux pour la reconnaissance du syndrome des enfants battus dans certaines sociétés même occidentales. Nous avons voulus exposer ce problème aux praticiens afin qu'il soit mieux diagnostiqué et pris en charge. La maltraitance physique des enfants est appelée à tort syndrome de Silverman qui ne regroupe en fait que les lésions squelettiques chez ces enfants tels que les fractures. Mots clés: Fracture, maltraitance, enfant, neuro-radiologie PMID:27642408

  9. Le Fort I Maxillary Advancement Using Distraction Osteogenesis

    PubMed Central

    Combs, Patrick D.; Harshbarger, Raymond J.

    2014-01-01

    Treatment of maxillary hypoplasia has traditionally involved conventional Le Fort I osteotomies and advancement. Advancements of greater than 10 mm risk significant relapse. This risk is greater in the cleft lip and palate population, whose anatomy and soft tissue scarring from prior procedures contributes to instability of conventional maxillary advancement. Le Fort I advancement with distraction osteogenesis has emerged as viable, stable treatment modality correction of severe maxillary hypoplasia in cleft, syndromic, and noncleft patients. In this article, the authors provide a review of current data and recommendations concerning Le Fort I advancement with distraction osteogenesis. In addition, they outline their technique for treating severe maxillary hypoplasia with distraction osteogenesis using internal devices. PMID:25383054

  10. Le zona ophtalmique: une dermatose rare chez l'enfant

    PubMed Central

    Zakia, Douhi; Meziane, Marieme; Salim, Gallouj; Zahra, Mernissi Fatima

    2015-01-01

    Le zona est dû a une réactivation du virus varicelle-zona (VZV) qui reste quiescent dans les ganglions sensitifs dorsaux après la varicelle. Le zona de l'enfant est rare et particulièrement la forme ophtalmique, qui peut être responsable de complications oculaires graves nécessitant une prise en charge adéquate et précoce. Il est parfois associé à des douleurs post-zostériennes dont le traitement est difficile. L'aciclovir per os administré dans les 72 heures après l’éruption a prouvé son efficacité dans la prévention des complications oculaires. Nous en rapportant un nouveaux cas chez un garçon immunocompétent de 9 ans, sans notion de varicelle antérieure. PMID:26955408

  11. Field resonance propulsion concept

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1979-01-01

    A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

  12. Revisiting the matricellular concept.

    PubMed

    Murphy-Ullrich, Joanne E; Sage, E Helene

    2014-07-01

    The concept of a matricellular protein was first proposed by Paul Bornstein in the mid-1990s to account for the non-lethal phenotypes of mice with inactivated genes encoding thrombospondin-1, tenascin-C, or SPARC. It was also recognized that these extracellular matrix proteins were primarily counter or de-adhesive. This review reappraises the matricellular concept after nearly two decades of continuous investigation. The expanded matricellular family as well as the diverse and often unexpected functions, cellular location, and interacting partners/receptors of matricellular proteins are considered. Development of therapeutic strategies that target matricellular proteins are discussed in the context of pathology and regenerative medicine.

  13. [Concepts of rational taxonomy].

    PubMed

    Pavlinov, I Ia

    2011-01-01

    The problems are discussed related to development of concepts of rational taxonomy and rational classifications (taxonomic systems) in biology. Rational taxonomy is based on the assumption that the key characteristic of rationality is deductive inference of certain partial judgments about reality under study from other judgments taken as more general and a priory true. Respectively, two forms of rationality are discriminated--ontological and epistemological ones. The former implies inference of classifications properties from general (essential) properties of the reality being investigated. The latter implies inference of the partial rules of judgments about classifications from more general (formal) rules. The following principal concepts of ontologically rational biological taxonomy are considered: "crystallographic" approach, inference of the orderliness of organismal diversity from general laws of Nature, inference of the above orderliness from the orderliness of ontogenetic development programs, based on the concept of natural kind and Cassirer's series theory, based on the systemic concept, based on the idea of periodic systems. Various concepts of ontologically rational taxonomy can be generalized by an idea of the causal taxonomy, according to which any biologically sound classification is founded on a contentwise model of biological diversity that includes explicit indication of general causes responsible for that diversity. It is asserted that each category of general causation and respective background model may serve as a basis for a particular ontologically rational taxonomy as a distinctive research program. Concepts of epistemologically rational taxonomy and classifications (taxonomic systems) can be interpreted in terms of application of certain epistemological criteria of substantiation of scientific status of taxonomy in general and of taxonomic systems in particular. These concepts include: consideration of taxonomy consistency from the

  14. Revisiting the matricellular concept

    PubMed Central

    Murphy-Ullrich, Joanne E.; Sage, E. Helene

    2015-01-01

    The concept of a matricellular protein was first proposed by Paul Bornstein in the mid-1990s to account for the non-lethal phenotypes of mice with inactivated genes encoding thrombospondin-1, tenascin-C, or SPARC. It was also recognized that these extracellular matrix proteins were primarily counter or de-adhesive. This review reappraises the matricellular concept after nearly two decades of continuous investigation. The expanded matricellular family as well as the diverse and often unexpected functions, cellular location, and interacting partners/receptors of matricellular proteins are considered. Development of therapeutic strategies that target matricellular proteins are discussed in the context of pathology and regenerative medicine. PMID:25064829

  15. Second law study of the Einstein refrigeration cycle

    SciTech Connect

    Shelton, S.V.; Delano, A.; Schaefer, L.A.

    1999-07-01

    After formulating the theory of relativity, Albert Einstein spent several years developing absorption refrigeration cycles. In 1930, he obtained a US patent for a unique single pressure absorption cycle. The single pressure throughout the cycle eliminates the need for the solution pump found in conventional absorption cycles. The Einstein cycle utilizes butane as a refrigerant, ammonia as a pressure equalizing fluid, and water as an absorbing fluid. This cycle is dramatically different in both concept and detail than the better known ammonia-water-hydrogen cycle. Recent studies have shown that the cycle's COP is 0.17, which is relatively low compared to two-pressure cycles. This limits the cycle to refrigeration applications where simplicity, compactness, silent operation, and low cost are the important characteristics. Improved efficiency would open up other potential applications. In this study, a comprehensive second law analysis of the cycle was carried out on each component and process to determine the thermodynamic source of the low efficiency. The results show that the reversible COP for the cycle is 0.58, and that the component with the largest irreversibility is the generator. The entropic average temperatures for the heat flows into and out of the cycle are 353 K for the generator, 266 K for the evaporator, and 315 K for the absorber/condenser. The COP degradations from the ideal due to irreversibilities are 0.12 for the evaporator, 0.11 for the absorber/condenser, and 0.17 for the generator. The generator irreversibility is due to the inherent temperature difference in the internal heat exchange. The results show that there is a large potential for increasing the cycle's efficiency through design changes to raise the low generator temperature and to reduce the large generator irreversibilities.

  16. The Unmanned Combat Aircraft (UCAV): The Point of View of an Aircraft Manufacturer (Les Avions de Combat Non Habites (UCAV) Le point de vue d’un avionneur)

    DTIC Science & Technology

    2000-04-01

    mes qu’ils ont con~us et plate-forme et son environnement (par d ~velopp6s diff~re des hypoth~ses qu’ils avaient prises exemple : I’anti-collision sol...dans lequel un intir&t sont des solutions techniquement envisageables croissant a pit se d ~gager pour promouvoir le pouvant pr6tendre r~pondre a ces...conception que permet d’envisager l’absence opirationnels- ii est possible d’envisager des concepts d 𔄀quipage A bord de ]a plate-formne. novateurs d ’avions

  17. Innatism, Concept Formation, Concept Mastery and Formal Education

    ERIC Educational Resources Information Center

    Winch, Christopher

    2015-01-01

    This article will consider the claim that the possession of concepts is innate rather than learned. Innatism about concept learning is explained through consideration of the work of Fodor and Chomsky. First, an account of concept formation is developed. Second the argument against the claim that concepts are learned through the construction of a…

  18. [Pleasure: Neurobiological conception and Freudian conception].

    PubMed

    Chenu, A; Tassin, J-P

    2014-04-01

    Despite many controversies the debate between psychoanalysis and neuroscience remains intense, all the more since the Freudian theory stands as a reference for a number of medical practitioners and faculty psychiatrists, at least in France. Instead of going on arguing we think that it may be more constructive to favour dialogue through the analysis of a precise concept developed in each discipline. The Freudian theory of pleasure, because it is based on biological principles, appears an appropriate topic to perform this task. In this paper, we aim at comparing Freud's propositions to those issued from recent findings in Neuroscience. Like all emotions, pleasure is acknowledged as a motivating factor in contemporary models. Pleasure can indeed be either rewarding when it follows satisfaction, or incentive when it reinforces behaviours. The Freudian concept of pleasure is more univocal. In Freud's theory, pleasure is assumed to be the result of the discharge of the accumulated excitation which will thus reduce the tension. This quantitative approach corresponds to the classical scheme that associates satisfaction and pleasure. Satisfaction of a need would induce both a decrease in tension and the development of pleasure. However, clinical contradictions to this model, such as the occasional co-existence between pleasure and excitation, drove Freud to suggest different theoretical reversals. Freud's 1905 publication, which describes how preliminary sexual pleasures contribute to an increased excitation and a sexual satisfaction, is the only analysis which provides an adapted answer to the apparent paradox of pleasure and excitation co-existence. Studies on the neurobiological mechanisms responsible for the development of pleasure may help to fill this gap in the Freudian theory. Activity of the mesolimbic dopaminergic pathway is strongly associated with the reward system. Experimental studies performed in animals have shown that increased dopaminergic activity in the

  19. Helium process cycle

    DOEpatents

    Ganni, Venkatarao

    2008-08-12

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  20. Helium process cycle

    DOEpatents

    Ganni, Venkatarao

    2007-10-09

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  1. [The concept of health in the General Health Law (1986)].

    PubMed

    Peral, D

    1993-01-01

    The 1986 "Le General de Sanidad" (Sanitary General Regulations) has been studied using the method of the "Topología del Discurso" in order to elucidate what are the thoughts of the lawmakers. The law protects not only the population of catastrophes as it happened with the choleric epidemic of the XIX century, but considers a new concept a sanitary wealth should be provided to the individuals. Together with this new concept there are new ones such as equality and universalization of the sanitary assistence that would be keys of the aim of the lawmakers: to coordinate all the State resources in the reform of the spanish sanity. This includes the integration of the Universities. This can help in the understanding of the dificulties in the development and aplication of the Law present reality.

  2. The receptor kinases LePRK1 and LePRK2 associate in pollen and when expressed in yeast, but dissociate in the presence of style extract

    PubMed Central

    Wengier, Diego; Valsecchi, Isabel; Cabanas, María Laura; Tang, Wei-hua; McCormick, Sheila; Muschietti, Jorge

    2003-01-01

    After pollen grains germinate on the stigma, pollen tubes traverse the extracellular matrix of the style on their way to the ovules. We previously characterized two pollen-specific, receptor-like kinases, LePRK1 and LePRK2, from tomato (Lycopersicon esculentum). Their structure and immunolocalization pattern and the specific dephosphorylation of LePRK2 suggested that these kinases might interact with signaling molecules in the style extracellular matrix. Here, we show that LePRK1 and LePRK2 can be coimmunoprecipitated from pollen or when expressed together in yeast. In yeast, their association requires LePRK2 kinase activity. In pollen, LePRK1 and LePRK2 are found in an ≈400-kDa protein complex that persists on pollen germination, but this complex is disrupted when pollen is germinated in vitro in the presence of style extract. In yeast, the addition of style extract also disrupts the interaction between LePRK1 and LePRK2. Fractionation of the style extract reveals that the disruption activity is enriched in the 3- to 10-kDa fraction. A component(s) in this fraction also is responsible for the specific dephosphorylation of LePRK2. The style component(s) that dephosphorylates LePRK2 is likely to be a heat-stable peptide that is present in exudate from the style. The generally accepted model of receptor kinase signaling involves binding of a ligand to extracellular domains of receptor kinases and subsequent activation of the signaling pathway by receptor autophosphorylation. In contrast to this typical scenario, we propose that a putative style ligand transduces the signal in pollen tubes by triggering the specific dephosphorylation of LePRK2, followed by dissociation of the LePRK complex. PMID:12748390

  3. Life cycle of cytosolic prions.

    PubMed

    Hofmann, Julia; Vorberg, Ina

    2013-01-01

    Prions are self-templating protein aggregates that were originally identified as the causative agent of prion diseases in mammals, but have since been discovered in other kingdoms. Mammalian prions represent a unique class of infectious agents that are composed of misfolded prion protein. Prion proteins usually exist as soluble proteins but can refold and assemble into highly ordered, self-propagating prion polymers. The prion concept is also applicable to a growing number of non-Mendelian elements of inheritance in lower eukaryotes. While prions identified in mammals are clearly pathogens, prions in lower eukaryotes can be either detrimental or beneficial to the host. Prion phenotypes in fungi are transmitted vertically from mother to daughter cells during cell division and horizontally during mating or abortive mating, but extracellular phases have not been reported. Recent findings now demonstrate that in a mammalian cell environment, protein aggregates derived from yeast prion domains exhibit a prion life cycle similar to mammalian prions propagated ex vivo. This life cycle includes a soluble state of the protein, an induction phase by exogenous prion fibrils, stable replication of prion entities, vertical transmission to progeny and natural horizontal transmission to neighboring cells. Our data reveal that mammalian cells contain all co-factors required for cytosolic prion propagation and dissemination. This has important implications for understanding prion-like properties of disease-related protein aggregates. In light of the growing number of identified functional amyloids, cell-to-cell propagation of cytosolic protein conformers might not only be relevant for the spreading of disease-associated proteins, but might also be of more general relevance under non-disease conditions.

  4. Life cycle of cytosolic prions

    PubMed Central

    Hofmann, Julia; Vorberg, Ina

    2013-01-01

    Prions are self-templating protein aggregates that were originally identified as the causative agent of prion diseases in mammals, but have since been discovered in other kingdoms. Mammalian prions represent a unique class of infectious agents that are composed of misfolded prion protein. Prion proteins usually exist as soluble proteins but can refold and assemble into highly ordered, self-propagating prion polymers. The prion concept is also applicable to a growing number of non-Mendelian elements of inheritance in lower eukaryotes. While prions identified in mammals are clearly pathogens, prions in lower eukaryotes can be either detrimental or beneficial to the host. Prion phenotypes in fungi are transmitted vertically from mother to daughter cells during cell division and horizontally during mating or abortive mating, but extracellular phases have not been reported. Recent findings now demonstrate that in a mammalian cell environment, protein aggregates derived from yeast prion domains exhibit a prion life cycle similar to mammalian prions propagated ex vivo. This life cycle includes a soluble state of the protein, an induction phase by exogenous prion fibrils, stable replication of prion entities, vertical transmission to progeny and natural horizontal transmission to neighboring cells. Our data reveal that mammalian cells contain all co-factors required for cytosolic prion propagation and dissemination. This has important implications for understanding prion-like properties of disease-related protein aggregates. In light of the growing number of identified functional amyloids, cell-to-cell propagation of cytosolic protein conformers might not only be relevant for the spreading of disease-associated proteins, but might also be of more general relevance under non-disease conditions. PMID:24021964

  5. Networks of Emotion Concepts

    PubMed Central

    Toivonen, Riitta; Kivelä, Mikko; Saramäki, Jari; Viinikainen, Mikko; Vanhatalo, Maija; Sams, Mikko

    2012-01-01

    The aim of this work was to study the similarity network and hierarchical clustering of Finnish emotion concepts. Native speakers of Finnish evaluated similarity between the 50 most frequently used Finnish words describing emotional experiences. We hypothesized that methods developed within network theory, such as identifying clusters and specific local network structures, can reveal structures that would be difficult to discover using traditional methods such as multidimensional scaling (MDS) and ordinary cluster analysis. The concepts divided into three main clusters, which can be described as negative, positive, and surprise. Negative and positive clusters divided further into meaningful sub-clusters, corresponding to those found in previous studies. Importantly, this method allowed the same concept to be a member in more than one cluster. Our results suggest that studying particular network structures that do not fit into a low-dimensional description can shed additional light on why subjects evaluate certain concepts as similar. To encourage the use of network methods in analyzing similarity data, we provide the analysis software for free use (http://www.becs.tkk.fi/similaritynets/). PMID:22276099

  6. Ares I concept illustration

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Shown is an illustration of the Ares I concept. The first stage will be a single, five-segment solid rocket booster derived from the space shuttle programs reusable solid rocket motor. The first stage is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama for NASA's Constellation program.

  7. Ares I concept illustration

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Shown is a concept illustration of Ares I which is an in-line, two-stage rocket that will transport the Orion Crew Exploration Vehicle to low earth orbit. Orion will accommodate as many as six astronauts. The first stage will consist of the five-segment solid rocket booster.

  8. Ares I concept illustration

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Shown is a concept illustration of the Ares I crew launch vehicle, left, and Ares V cargo launch vehicle. Ares I will carry the Orion Crew Exploration Vehicle to space. Ares V will serve as NASA's primary vehicle for delivery of large-scale hardware to space.

  9. Learning Statistical Concepts

    ERIC Educational Resources Information Center

    Akram, Muhammad; Siddiqui, Asim Jamal; Yasmeen, Farah

    2004-01-01

    In order to learn the concept of statistical techniques one needs to run real experiments that generate reliable data. In practice, the data from some well-defined process or system is very costly and time consuming. It is difficult to run real experiments during the teaching period in the university. To overcome these difficulties, statisticians…

  10. Photoelectrochemistry: Introductory Concepts.

    ERIC Educational Resources Information Center

    Finklea, Harry O.

    1983-01-01

    Photoelectrochemistry is based on the semiconductor electrode. It is the semiconductor's ability to absorb light and convert it to electrical and/or chemical energy that forms the basis for the semiconductor liquid-junction solar cell. To understand how this occurs, solid-state physics concepts are discussed. (Author/JN)

  11. The Concept of Culture.

    ERIC Educational Resources Information Center

    Wilson, James Q.

    1993-01-01

    Explores the concept of culture as a factor in the well-being of children. Holding students accountable for their behavior, holding schools accountable for activities and achievements of students, and inducing parents to support their children in school require a cultural change in how we look at schooling. (SLD)

  12. Concept of Operations: Essence

    SciTech Connect

    Hutton, William J.

    2014-04-01

    This concept of operations is designed to give the reader a brief overview of the National Rural Electric Cooperative Association’s Essence project and a description of the Essence device design. The data collected by the device, how the data are used, and how the data are protected are also discussed in this document.

  13. Using Concept Cartoons

    ERIC Educational Resources Information Center

    Dabell, John

    2008-01-01

    Concept cartoons are cognitive drawings or "visual disagreements" that use a cartoon-style design to present mathematical conversations inside speech bubbles. The viewpoints portrayed are all different and it is this difference that acts as a catalyst for further conversations, as learners talk together to discuss their thinking. They make…

  14. Climatic Concepts and Regions.

    ERIC Educational Resources Information Center

    Thomas, Paul F.

    Designed for students in grades 7 through 12, this teaching unit presents illustrative resource materials depicting concepts related to climate and geographic regions. Emphasis is on giving students an understanding of climatic elements and factors, not as isolated, disjointed entities, but as a dynamic interplay of forces having a very definite…

  15. Embodying Policy Concepts

    ERIC Educational Resources Information Center

    Evans, John; Davies, Brian

    2012-01-01

    This article introduces some of the key concepts that we have used in our research to help illuminate the multiple and different ways in which apparently ubiquitous health policies relating to obesity, exercise, diet and health are mediated and shaped both globally and nationally, as well as within regional, school and other contexts. The analyses…

  16. Children's Conceptions of Trust.

    ERIC Educational Resources Information Center

    Kahn, Peter H., Jr.; Turiel, Elliot

    Aware that children conceive of different types of trust, a study examined 60 children's conception of trust. The subjects comprised three age groups: 6-7 years old, 8-9 years old, and 10-11 years old. Each subject was interviewed on the basis of three stories. The stories depicted a hypothesized violation of trust in a moral context (lying),…

  17. The Concept of "Teachability."

    ERIC Educational Resources Information Center

    Tubbs, Nigel

    2003-01-01

    Asserts that "teachability" is a speculative concept that has for its form and content the absolute, suggesting that its dialectical movement and speculative significance are mis-recognized when the illusionary nature of its constitutive moments is suppressed. The essay outlines the speculative nature of the master/slave relationship in Hegel's…

  18. Naive Conceptions of Motion.

    ERIC Educational Resources Information Center

    McCloskey, Michael

    Two experiments were conducted to characterize the system of beliefs that make up the naive impetus theory of motion and to determine what effects physics instruction has on students' conceptions of motion. Thirteen college students were asked to solve several quantitative problems and were interviewed about their answers in the first experiment.…

  19. Teaching Weather Concepts.

    ERIC Educational Resources Information Center

    Sebastian, Glenn R.

    Ten exercises based on the weather map provided in the national newspaper "U.S.A. Today" are used to teach intermediate grade students about weather. An overview describes the history of "U.S.A. Today," the format of the newspaper's weather map, and the map's suitability for teaching weather concepts. Specific exercises, which are briefly…

  20. I Teach Concepts.

    ERIC Educational Resources Information Center

    Januszewski, Alan

    This paper describes the author's views on and approach to teaching about educational technology. The author teaches concepts, with an emphasis on "teaching about" rather than "teaching how". The author's educational background and experiences, and their influence on his current views are described. While the definitions of educational technology…

  1. Creativity: Concepts and Explorations.

    ERIC Educational Resources Information Center

    Rookey, T. Jerome

    The lack of a universal definition of creativity has led to the assessment of creativity according to the definition favored by the evaluator. These assessments fall into four groups. The first centers around the concept of the creative product; it assesses a tangible event or relationship that results from the creative process, which is implied…

  2. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  3. Changing Conceptions of Nonprofessionals.

    ERIC Educational Resources Information Center

    Vanek, Linda; Powell, Thomas J.

    The authors distinguish between the therapeutically-oriented and the socializationally-oriented nonprofessionals, and maintain that both are valuable in a comprehensive program and neither one is uniquely effective. Hence, task assignments should represent the differing orientations as should training programs. A realistic conception of the types…

  4. Advanced Concept Modeling

    NASA Technical Reports Server (NTRS)

    Chaput, Armand; Johns, Zachary; Hodges, Todd; Selfridge, Justin; Bevirt, Joeben; Ahuja, Vivek

    2015-01-01

    Advanced Concepts Modeling software validation, analysis, and design. This was a National Institute of Aerospace contract with a lot of pieces. Efforts ranged from software development and validation for structures and aerodynamics, through flight control development, and aeropropulsive analysis, to UAV piloting services.

  5. Some Core Contested Concepts

    ERIC Educational Resources Information Center

    Chomsky, Noam

    2015-01-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and…

  6. Entropy, a Protean Concept

    NASA Astrophysics Data System (ADS)

    Balian, Roger

    We review at a tutorial level the many aspects of the concept of entropy and their interrelations, in thermodynamics, information theory, probability theory and statistical physics. The consideration of relevant entropies and the identification of entropy with missing information enlighten the paradoxes of irreversibility and of Maxwell's demon.

  7. Mass Producing Concept Inventories

    NASA Astrophysics Data System (ADS)

    Garvin-Doxas, K.; Klymkowsky, M.; Doxas, I.

    2005-12-01

    Concept Inventories are research based assessment instruments which derive their validity and reliability from well researched distracters that represent students' dominant misconceptions in the field. They have formed the backbone of research based reform efforts in Physics by providing valid, reliable common assessment instruments with which to evaluate different teaching approaches and materials, and many disciplines are in the process of developing large numbers of Concept Inventories for their own subject areas. Unfortunately, Concept Inventories are labour and time intensive, with instruments taking anywhere from 2-8 years to develop, and correspondingly high price tags. The time and cost is directly related to the fact that valid, reliable instruments require mapping the dominant misconceptions in a field, which is usually a time consuming and labour intensive task. This paper will describe how we use Latent Semantic Analysis (LSA) with unsupervised clustering of the LSA vectors to identify and classify misconceptions in various science disciplines, considerably speeding up the process of misconception discovery and classification. The paper will present results from Astronomy and Biology, and will describe current efforts to develop a Concept Inventory for Space Physics.

  8. Concepts in Environmental Education.

    ERIC Educational Resources Information Center

    Hopkins, Sally

    Presented is a discussion of the components and concepts of an ecology typical of the coastal southeastern United States. Principles presented are applicable to other areas. The discussion includes several major sections: the environment, wildlife management, freshwater ecosystems, and the estuarine environment. Numerous figures and illustrations…

  9. Understanding the Agribusiness Concept.

    ERIC Educational Resources Information Center

    Lee, Jasper S.

    Designed to aid in learning the main ideas of the agribusiness concept, this document answers the following questions, treating each answer in a separate explanatory section: (1) What is the meaning of the terms "agriculture" and "agribusiness"? (2) What is the relationship of agriculture and agribusiness? (3) What is involved in tracing an…

  10. Concept-Based Learning

    ERIC Educational Resources Information Center

    Schill, Bethany; Howell, Linda

    2011-01-01

    A major part of developing concept-based instruction is the use of an overarching idea to provide a conceptual lens through which students view the content of a particular subject. By using a conceptual lens to focus learning, students think at a much deeper level about the content and its facts (Erickson 2007). Therefore, the authors collaborated…

  11. Two Conceptions of Virtue

    ERIC Educational Resources Information Center

    Hill, Thomas E., Jr.

    2013-01-01

    The general questions are: what is virtue and how can it be cultivated? The specific focus is on the conceptions of virtue in the works of Immanuel Kant and John Rawls. Kant regarded virtue as a good will that is also strong enough to resist contrary passions, impulses, and inclinations. Childhood training can prepare children for virtue, but…

  12. Advanced Civilian Aeronautical Concepts

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.

    1996-01-01

    Paper discusses alternatives to currently deployed systems which could provide revolutionary improvements in metrics applicable to civilian aeronautics. Specific missions addressed include subsonic transports, supersonic transports and personal aircraft. These alternative systems and concepts are enabled by recent and envisaged advancements in electronics, communications, computing and Designer Fluid Mechanics in conjunction with a design approach employing extensive synergistic interactions between propulsion, aerodynamics and structures.

  13. Mapping Sociological Concepts.

    ERIC Educational Resources Information Center

    Trepagnier, Barbara

    2002-01-01

    Focuses on the use of cognitive mapping within sociology. Describes an assignment where students created a cognitive map that focused on names of theorists and concepts related to them. Discusses sociological imagination in relation to cognitive mapping and the assessment of the assignment. (CMK)

  14. DSMS science operations concept

    NASA Technical Reports Server (NTRS)

    Connally, M. J.; Kuiper, T. B.

    2001-01-01

    The Deep Space Mission System (DSMS) Science Operations Concept describes the vision for enabling the use of the DSMS, particularly the Deep Space Network (DSN) for direct science observations in the areas of radio astronomy, planetary radar, radio science and VLBI.

  15. Advanced heat pump cycle

    SciTech Connect

    Groll, E.A.; Radermacher, R.

    1993-07-01

    The desorption and absorption process of a vapor compression heat pump with a solution circuit (VCHSC) proceeds at gliding temperature intervals, which can be adjusted over a wide range. In case that the gliding temperature intervals in the desorber and the absorber overlap, a modification of the VCHSC employing a desorber/absorber heat exchange (DAHX) can be introduced, which results in an extreme reduction of the pressure ratio. Although the DAHX-cycle has features of a two-stage cycle, it still requires only one solution pump, one separator and one compressor. Such a cycle for the working pair ammonia/water is built in the Energy Laboratory of the Center for Environmental Energy Engineering at the University of Maryland. The experimental results obtained with the research plant are discussed and compared to those calculated with a simulation program. The possible temperature lift between heat source and heat sink depending on the achievable COP are presented.

  16. Superfluid thermodynamic cycle refrigerator

    DOEpatents

    Swift, Gregory W.; Kotsubo, Vincent Y.

    1992-01-01

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

  17. Superfluid thermodynamic cycle refrigerator

    DOEpatents

    Swift, G.W.; Kotsubo, V.Y.

    1992-12-22

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He-[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs.

  18. The global sulfur cycle

    NASA Technical Reports Server (NTRS)

    Sagan, D. (Editor)

    1985-01-01

    The results of the planetary biology microbial ecology's 1984 Summer Research Program, which examined various aspects of the global sulfur cycle are summarized. Ways in which sulfur flows through the many living and chemical species that inhabit the surface of the Earth were investigated. Major topics studied include: (1) sulfur cycling and metabolism of phototropic and filamentous sulfur bacteria; (2) sulfur reduction in sediments of marine and evaporite environments; (3) recent cyanobacterial mats; (4) microanalysis of community metabolism in proximity to the photic zone in potential stromatolites; and (5) formation and activity of microbial biofilms on metal sulfides and other mineral surfaces. Relationships between the global sulfur cycle and the understanding of the early evolution of the Earth and biosphere and current processes that affect global habitability are stressed.

  19. 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.

  20. Modified Purex first-cycle extraction for neptunium recovery

    SciTech Connect

    Dinh, Binh; Moisy, Philippe; Baron, Pascal; Calor, Jean-Noel; Espinoux, Denis; Lorrain, Brigitte; Benchikouhne-Ranchoux, Magali

    2008-07-01

    A new PUREX first-cycle flowsheet was devised to enhance the extraction yield of neptunium at the extraction step of this cycle. Simulation results (using a qualified process-simulation tool), le d to raising the nitric acid concentration of the feed from 3 M to 4.5 M to allow extraction of more than 99% of the neptunium. This flowsheet was operated in the shielded process cell of ATALANTE facility using pulsed columns and mixer-settlers banks. A 15 kg quantity of genuine oxide fuel of average burn up of 52 GWd/t with cooling time of nearly five years was treated, and the neptunium extraction yield obtained was greater than 99.6%. (authors)

  1. Rocketdyne RBCC Engine Concept Development

    NASA Technical Reports Server (NTRS)

    Ratckin, G.; Goldman, A.; Ortwerth, P.; Weisberg, S.

    1999-01-01

    Boeing Rocketdyne is pursuing the development of Rocket Based Combined Cycle (RBCC), propulsion systems as demonstrated by significant contract work in the hypersonic arena (ART, NASP, SCT, system studies) and over 12 years of steady company discretionary investment. The Rocketdyne concept is a fixed geometry integrated rocket, ramjet, scramjet which is hydrogen fueled and uses hydrogen regenerative cooling. The baseline engine structural configuration uses an integral structure that eliminates panel seals. seal purge gas, and closeout side attachments. Rocketdyne's experimental RBCC engine (Engine A5) was constructed under contract with the NASA Marshall Space Flight Center. Engine A5 models the complete flight engine flowpath consisting of an inlet, isolator, airbreathing combustor and nozzle. High performance rocket thrusters are integrated into the engine to enable both air-augmented rocket (AAR) and pure rocket operation. Engine A5 was tested in CASL's new FAST facility as an air-augmented rocket, a ramjet and a pure rocket. Measured performance demonstrated vision vehicle performance levels for Mach 3 AAR operation and ramjet operation from Mach 3 to 4. Rocket mode performance was above predictions. For the first time. testing also demonstrated transition from AAR operation to ramjet operation. This baseline configuration has also been shown, in previous testing, to perform well in the scramjet mode.

  2. Cycles in fossil diversity

    SciTech Connect

    Rohde, Robert A.; Muller, Richard A.

    2004-10-20

    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

  3. Revenue cycle management.

    PubMed

    Manley, Ray; Satiani, Bhagwan

    2009-11-01

    With the widening gap between overhead expenses and reimbursement, management of the revenue cycle is a critical part of a successful vascular surgery practice. It is important to review the data on all the components of the revenue cycle: payer contracting, appointment scheduling, preregistration, registration process, coding and capturing charges, proper billing of patients and insurers, follow-up of accounts receivable, and finally using appropriate benchmarking. The industry benchmarks used should be those of peers in identical groups. Warning signs of poor performance are discussed enabling the practice to formulate a performance improvement plan.

  4. Solar 22 years cycle

    NASA Astrophysics Data System (ADS)

    Kotov, Valery A.; Sanchez, Francis M.

    2017-01-01

    Seven observatories performed in 1968-2015 numerous daily measurements of general magnetic field of the Sun seen as a star (of a mean line-of-sight field component of the visible solar hemisphere). The new data 2013-2015 confirmed the recent prediction about saw-edged profile of the mean curve of the Hale's 22 years magnetic cycle and, thus, a hypothesis about its cosmological (partial) origin. This is supported by a special analysis of epochs of extrema of Wolf's sunspot number, demonstrating a remarkable stability, since Galileo's time, of the initial phase of the cycle, which can hardly be explained by dynamo theory exclusively.

  5. Cycles in fossil diversity.

    PubMed

    Rohde, Robert A; Muller, Richard A

    2005-03-10

    It is well known that the diversity of life appears to fluctuate during the course of the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 million years ago). Here we show, using Sepkoski's compendium of the first and last stratigraphic appearances of 36,380 marine genera, a strong 62 +/- 3-million-year cycle, which is particularly evident in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance we also consider the contributions of environmental factors, and possible causes.

  6. Global water cycle

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Christy, John R.; Goodman, Steven J.; Miller, Tim L.; Fitzjarrald, Dan; Lapenta, Bill; Wang, Shouping

    1991-01-01

    The primary objective is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates changes on both global and regional scales. The following subject areas are covered: (1) water vapor variability; (2) multi-phase water analysis; (3) diabatic heating; (4) MSU (Microwave Sounding Unit) temperature analysis; (5) Optimal precipitation and streamflow analysis; (6) CCM (Community Climate Model) hydrological cycle; (7) CCM1 climate sensitivity to lower boundary forcing; and (8) mesoscale modeling of atmosphere/surface interaction.

  7. Global water cycle

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin; Goodman, Steven J.; Christy, John R.; Fitzjarrald, Daniel E.; Chou, Shi-Hung; Crosson, William; Wang, Shouping; Ramirez, Jorge

    1993-01-01

    This research is the MSFC component of a joint MSFC/Pennsylvania State University Eos Interdisciplinary Investigation on the global water cycle extension across the earth sciences. The primary long-term objective of this investigation is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates change on both global and regional scales. Significant accomplishments in the past year are presented and include the following: (1) water vapor variability; (2) multi-phase water analysis; (3) global modeling; and (4) optimal precipitation and stream flow analysis and hydrologic processes.

  8. Microsystem Cooler Concept Developed and Being Fabricated

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.

    2005-01-01

    A patented microsystem cooler concept has been developed by the NASA Glenn Research Center. It incorporates diaphragm actuators to produce the Stirling refrigeration cycle within a planar configuration compatible with the thermal management of electronics, sensors, optical and radiofrequency systems, microarrays, and other microsystems. The microsystem cooler is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Johns Hopkins University Applied Physics Laboratory is conducting development testing and fabrication of a prototype under a grant from Glenn.

  9. Artist's Concept of the Orbiting Carbon Observatory

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Artist's concept of the Orbiting Carbon Observatory. The mission, scheduled to launch in early 2009, will be the first spacecraft dedicated to studying atmospheric carbon dioxide, the principal human-produced driver of climate change. It will provide the first global picture of the human and natural sources of carbon dioxide and the places where this important greenhouse gas is stored. Such information will improve global carbon cycle models as well as forecasts of atmospheric carbon dioxide levels and of how our climate may change in the future.

  10. Separations innovative concepts: Project summary

    SciTech Connect

    Lee, V.E.

    1988-05-01

    This project summary includes the results of 10 innovations that were funded under the US Department's Innovative Concept Programs. The concepts address innovations that can substantially reduce the energy used in industrial separations. Each paper describes the proposed concept, and discusses the concept's potential energy savings, market applications, technical feasibility, prior work and state of the art, and future development needs.

  11. Concepts in Activities and Discourses

    ERIC Educational Resources Information Center

    Greeno, James G.

    2012-01-01

    The articles in this special issue make valuable contributions toward a scientific understanding of concepts that is broader than the traditional view that has focused on categorizing by individuals. I propose considering concepts for categorization as a special case of concepts. At their clearest, they can be referred to as "formal concepts," or…

  12. Key Concepts in Informatics: Algorithm

    ERIC Educational Resources Information Center

    Szlávi, Péter; Zsakó, László

    2014-01-01

    "The system of key concepts contains the most important key concepts related to the development tasks of knowledge areas and their vertical hierarchy as well as the links of basic key concepts of different knowledge areas." (Vass 2011) One of the most important of these concepts is the algorithm. In everyday life, when learning or…

  13. Component test program for variable-cycle engines

    NASA Technical Reports Server (NTRS)

    Powers, A. G.; Whitlow, J. B.; Stitt, L. E.

    1976-01-01

    Variable cycle engine (VCE) concepts for a supersonic cruise aircraft were studied. These VCE concepts incorporate unique critical components and flow path arrangements that provide good performance at both supersonic and subsonic cruise and appear to be economically and environmentally viable. Certain technologies were identified as critical to the successful development of these engine concepts and require considerable development and testing. The feasibility and readiness of the most critical VCE technologies, was assessed, a VCE component test program was initiated. The variable stream control engine (VSCE) component test program, tested and evaluated an efficient low emission duct burner and a quiet coannular ejector nozzle at the rear of a rematched F100 engine.

  14. Optimizing product life cycle processes in design phase

    NASA Astrophysics Data System (ADS)

    Faneye, Ola. B.; Anderl, Reiner

    2002-02-01

    Life cycle concepts do not only serve as basis in assisting product developers understand the dependencies between products and their life cycles, they also help in identifying potential opportunities for improvement in products. Common traditional concepts focus mainly on energy and material flow across life phases, necessitating the availability of metrics derived from a reference product. Knowledge of life cycle processes won from an existing product is directly reused in its redesign. Depending on sales volume nevertheless, the environmental impact before product optimization can be substantial. With modern information technologies today, computer-aided life cycle methodologies can be applied well before product use. On the basis of a virtual prototype, life cycle processes are analyzed and optimized, using simulation techniques. This preventive approach does not only help in minimizing (or even eliminating) environmental burdens caused by product, costs incurred due to changes in real product can also be avoided. The paper highlights the relationship between product and life cycle and presents a computer-based methodology for optimizing the product life cycle during design, as presented by SFB 392: Design for Environment - Methods and Tools at Technical University, Darmstadt.

  15. Answering Key Fuel Cycle Questions

    SciTech Connect

    Steven J. Piet; Brent W. Dixon; J. Stephen Herring; David E. Shropshire; Mary Lou Dunzik-Gougar

    2003-10-01

    The Advanced Fuel Cycle Initiative (AFCI) program has both “outcome” and “process” goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geological repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are readiness to proceed and adaptability and robustness in the face of uncertainties. A classic decision-making approach to such a multi-attribute problem would be to weight individual quantified criteria and calculate an overall figure of merit. This is inappropriate for several reasons. First, the goals are not independent. Second, the importance of different goals varies among stakeholders. Third, the importance of different goals is likely to vary with time, especially the “energy future.” Fourth, some key considerations are not easily or meaningfully quantifiable at present. Instead, at this point, we have developed 16 questions the AFCI program should answer and suggest an approach of determining for each whether relevant options improve meeting each of the program goals. We find that it is not always clear which option is best for a specific question and specific goal; this helps identify key issues for future work. In general, we suggest attempting to create as many win-win decisions (options that are attractive or neutral to most goals) as possible. Thus, to help clarify why the program is exploring the options it is, and to set the stage for future narrowing of options, we have developed 16 questions, as follows: · What are the AFCI program goals? · Which potential waste disposition approaches do we plan for? · What are the major separations, transmutation, and fuel options? · How do we address proliferation resistance? · Which potential energy futures do we plan for? · What potential external triggers do we

  16. Freehand Sketching as a Catalyst for Developing Concept Driven Competencies

    ERIC Educational Resources Information Center

    Lane, Diarmaid; Seery, Niall

    2011-01-01

    At a time when concept driven competencies are perceived to be critical in redefining effective technological education, the introduction of Design and Communication Graphics at senior cycle in Irish high schools has broad implications. Students now have the potential to explore applied geometries, integrated with conceptual thinking in addition…

  17. Menstrual Cycle Effects on Attitudes toward Romantic Kissing

    PubMed Central

    Wlodarski, Rafael; Dunbar, Robin I. M.

    2015-01-01

    Hormonal changes associated with the human menstrual cycle have been previously found to affect female mate preference, whereby women in the late follicular phase of their cycle (i.e., at higher risk of conception) prefer males displaying putative signals of underlying genetic fitness. Past research also suggests that romantic kissing is utilized in human mating contexts to assess potential mating partners. The current study examined whether women in their late follicular cycle phase place greater value on kissing at times when it might help serve mate assessment functions. Using an international online questionnaire, results showed that women in the follicular phase of their menstrual cycle felt that kissing was more important at initial stages of a relationship than women in the luteal phase of their cycle. Furthermore, it was found that estimated progesterone levels were a significant negative predictor for these ratings. PMID:24078298

  18. Decolonizing the Choctaws: Teaching LeAnne Howe's "Shell Shaker"

    ERIC Educational Resources Information Center

    Hollrah, Patrice

    2004-01-01

    "Shell Shaker" (2001) by LeAnne Howe (Choctaw) is a novel that gives students an opportunity to learn that the history and culture of the Choctaw Nation of Oklahoma are alive today. Winner of the Before Columbus Foundation American Book Award in 2002, the novel deals with two parallel stories that converge in the present, one about the eighteenth…

  19. Errol Le Cain: The Very Best Aspects of Book Illustration.

    ERIC Educational Resources Information Center

    Eve, Matthew

    1999-01-01

    Examines Errol Le Cain's eclectic illustration contributions to children's literature throughout his life. Relates life experiences and influences to his work as an illustrator. Suggests that he constantly changed and adapted his style according to the prose, its tone, and the setting, unlike most other contemporary British book artists. (SC)

  20. MoLeNET Mobile Learning Conference 2009: Research Papers

    ERIC Educational Resources Information Center

    Guy Parker, Ed.

    2010-01-01

    The Mobile Learning Network (MoLeNET) is a unique collaborative approach to encouraging, supporting, expanding and promoting mobile learning, primarily in English post-14 education and training, via supported shared cost mobile learning projects. Collaboration at national level involves participating institutions and the Learning and Skills…

  1. Some special features of the le chatelier-braun principle

    NASA Astrophysics Data System (ADS)

    Nesis, E. I.; Skibin, Yu. N.

    2000-07-01

    The relaxation reaction of a system that follows from the Le Chatelier-Braun principle and weakens the result of an external influence turns out to be more intense under a complex action. A method for quantitative determination of the weakening effect for simple and complex actions is suggested.

  2. Restorative Justice Scripts in Ursula K. Le Guin's "Voices"

    ERIC Educational Resources Information Center

    Oziewicz, Marek C.

    2011-01-01

    This essay examines restorative justice scripting in "Voices", the second volume of Ursula K. Le Guin's "Annals of the Western Shore." Narrated by a rape-child, "Voices" is the story of an occupied city-state and of how the conquered and the conquerors negotiate a formula for peaceful coexistence. They are able to do…

  3. Expectation of "Le Petit Prince"'s home

    NASA Astrophysics Data System (ADS)

    Abe, Masanao; Ohba, Yohei; Ishiguro, Masateru; Hasegawa, Sunao; Fuse, Tetsuharu

    2002-11-01

    We observed a few hundred meter-sized asteroid like "Le Petit Prince"'s home using Subaru telescope. The name of the asteroid is 1998 SF36, which is a target object of the Japanese asteroid sample return mission, MUSES-C. We report the results of the observations and expect the true picture of the tiny-sized asteroid.

  4. Le Chatelier's Principle and the Prediction Temperature on Solubilities.

    ERIC Educational Resources Information Center

    Fernandez-Prini, R.

    1982-01-01

    Discusses Le Chatelier's Principle from a thermodynamic perspective and applies it to the effect of temperature on the solubility of gases in liquids. Rationale of this discussion is to evaluate data in a previous article claimed to be contradictory to the Principle. (Author/JN)

  5. Le Chatelier's Principle Applied to the Temperature Dependence of Solubility.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1984-01-01

    One effect of temperature is its influence on solubility, and that effect is used as a common example when teaching Le Chatelier's principle. Attempts to clarify the question of whether the principle holds in the case of the solubility of ionic compounds in water by investigating the literature data in detail. (JN)

  6. Le Dernier Cartoucherie: Refuge and the Performance of Care

    ERIC Educational Resources Information Center

    Fisek, Emine

    2008-01-01

    In 2003, the Paris-based theatre company Theatre du Soleil launched "Le Dernier Caravanserail: Odyssees", a collaborative creation based on stories that company members had collected from refugees at the Sangatte refugee camp outside Calais, among other locations. Scenes of moral reasoning dotted the six-hour spectacle, calling to mind…

  7. The Discourse Function of the Verbal Suffix -Le in Mandarin.

    ERIC Educational Resources Information Center

    Chu, Chauncey C.; Chang, W. Vincent

    It is proposed that the functions of the Mandarin verbal suffix "-le" are three: (1) for marking non-continual factual actions or events; (2) for indicating the "peak" in an event line; and (3) for explicitly marking anteriority of an action or event. Observations of written language drawn from newspaper articles and…

  8. Les enfants et le theatre (Children and the Theater).

    ERIC Educational Resources Information Center

    Ferrari, Josephine

    1980-01-01

    Describes a project involving the presentation of "Le petit prince" as an exercise in dramatics by children in a French-Italian bilingual education class. Two steps in the process are discussed: (1) the study of the text, and (2) the activities involved in getting the play ready for performance. (AMH)

  9. LHC, le Big Bang en éprouvette

    ScienceCinema

    None

    2016-07-12

    Notre compréhension de l’Univers est en train de changer… Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l’innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur de recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008

  10. LHC, le Big Bang en éprouvette

    SciTech Connect

    2010-04-07

    Notre compréhension de l’Univers est en train de changer… Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l’innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur de recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008

  11. Quantifying the Adaptive Cycle

    EPA Science Inventory

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative...

  12. Assisted Cycling Tours

    ERIC Educational Resources Information Center

    Hollingsworth, Jan Carter

    2008-01-01

    This article discusses Assisted Cycling Tours (ACT), a Westminster, Colorado based 501(c)3, non-profit that is offering the joy of bicycle tours in breathtaking, scenic locations to children and adults with developmental and physical disabilities and their families. ACT was founded by Bob Matter and his son David with a goal of opening up the…

  13. Mosquito Life Cycle

    EPA Pesticide Factsheets

    Knowing the stages of the mosquito's life will help you prevent mosquitoes around your home and help you choose the right pesticides for your needs, if you decide to use them. All mosquito species go through four distinct stages during their live cycle.

  14. 90-Day Cycle Handbook

    ERIC Educational Resources Information Center

    Park, Sandra; Takahashi, Sola

    2013-01-01

    90-Day Cycles are a disciplined and structured form of inquiry designed to produce and test knowledge syntheses, prototyped processes, or products in support of improvement work. With any type of activity, organizations inevitably encounter roadblocks to improving performance and outcomes. These barriers might include intractable problems at…

  15. LIFE-CYCLE ASSESSMENT

    EPA Science Inventory

    Life Cycle Assessment, or LCA, is an environmental accounting and mangement approach that consider all the aspects of resource use and environmental releases associated with an industrial system from cradle-to-grave. Specifically, it is a holistic view of environmental interacti...

  16. The Science of Cycling

    ERIC Educational Resources Information Center

    Crompton, Zoe; Daniels, Shelley

    2014-01-01

    Children are engaged by finding out about science in the real world (Harlen, 2010). Many children will be cyclists or will have seen or heard about the success of British cyclists in the Olympics and the Tour de France. This makes cycling a good hook to draw children into learning science. It is also a good cross-curricular topic, with strong…

  17. Re-Cycling

    ERIC Educational Resources Information Center

    Brown, Robert W.; Covault, Corbin E.

    2015-01-01

    An old comedy routine on Saturday Night Live by Father Guido Sarducci introduced a "Five-Minute University," because five minutes is all that's remembered after graduation anyway. In counterpoint, we discuss "cycling," a teaching method for memory enhancement. Our principal implementation consists of offering a simple version…

  18. MERCURY CYCLING AND BIOMAGNIFICATION

    EPA Science Inventory

    Mercury cycling and biomagnification was studied in man-made ponds designed for watering livestock on the Cheyenne River Sioux Reservation in South Dakota. Multiple Hg species were quantified through multiple seasons for 2 years in total atmospheric deposition samples, surface wa...

  19. Please Reduce Cycle Time

    DTIC Science & Technology

    2014-12-01

    Defense AT&L: November–December 2014 4 Please Reduce Cycle Time Brian Schultz “Time is what we want most but what we use worst.” — William Penn ...Schultz is a professor of program management at the Defense Acquisition University’s Mid-Atlantic Region in California, Md. As William Penn noted

  20. The Cycle of Violence.

    ERIC Educational Resources Information Center

    Widom, Cathy Spatz

    1989-01-01

    Discussed is a project to compare a sample of 20-year-old abuse and neglect cases to a matched control group to determine the extent to which these groups have perpetuated the violence cycle. Findings are reported that show increased risk of adult violence for formerly abused children. (CW)

  1. Advanced ramjet concepts program

    NASA Technical Reports Server (NTRS)

    Leingang, J. L.

    1992-01-01

    Uniquely advantageous features, on both the performance and weight sides of the ledger, can be achieved through synergistic design integration of airbreathing and rocket technologies in the development of advanced orbital space transport propulsion systems of the combined cycle type. In the context of well understood advanced airbreathing and liquid rocket propulsion principles and practices, this precept of synergism is advanced mainly through six rather specific examples. These range from the detailed component level to the overall vehicle system level as follows: using jet compression; achieving a high area ratio rocket nozzle; ameliorating gas generator cycle rocket system deficiencies; using the in-duct special rocket thrust chamber assembly as the principal scramjet fuel injection operation; using the unstowed, covered fan as a duct closure for effecting high area ratio rocket mode operation; and creating a unique airbreathing rocket system via the onboard, cryogenic hydrogen induced air liquefaction process.

  2. Portevin-Le Chatelier effect under cyclic loading: experimental and numerical investigations

    NASA Astrophysics Data System (ADS)

    Mazière, M.; Pujol d'Andrebo, Q.

    2015-10-01

    The Portevin-Le Chatelier (PLC) effect is generally evidenced by the apparition of serrated yielding under monotonic tensile loading conditions. It appears at room temperature in some aluminium alloys, around ? in some steels and in many other metallic materials. This effect is associated with the propagation of bands of plastic deformation in tensile specimens and can in some cases lead to unexpected failures. The PLC effect has been widely simulated under monotonic conditions using finite elements and an appropriate mechanical model able to reproduce serrations and strain localization. The occurrence of serrations can be predicted using an analytical stability analysis. Recently, this serrated yielding has also been observed in specimens made of Cobalt-based superalloy under cyclic loading, after a large number of cycles. The mechanical model has been identified in this case to accurately reproduce this critical number of cycle where serrations appear. The associated apparition of localized bands of deformation in specimens and their influence on its failure has also been investigated using finite element simulations.

  3. A model regenerator for a Stirling cycle

    NASA Astrophysics Data System (ADS)

    Carolan, James

    2001-05-01

    An essential feature of the engine patented by Robert Stirling in 1817 was the careful description of the idea of regeneration. In the standard thermodynamic cycle representation of the engine, regeneration is the storing and the reusing of the thermal energy released in the constant volume cooling part of the cycle. Due to the difficulty in treating regeneration quantitatively, introductory physics texts generally either ignore the concept or assume the regeneration to be perfect. As a result students obtain little or no understanding of regeneration. In addition there seem to be differing views in various texts about the efficiency of Stirling engines. In this work a simple finite element model regenerator is presented with which one can do simple calculations. The model does not accurately represent actual regeneration in a practical engine. But the model might help students gain better insight into Stirling engine efficiency and the idea of regeneration.

  4. Automatic female dehumanization across the menstrual cycle.

    PubMed

    Piccoli, Valentina; Fantoni, Carlo; Foroni, Francesco; Bianchi, Mauro; Carnaghi, Andrea

    2016-11-30

    In this study, we investigate whether hormonal shifts during the menstrual cycle contribute to the dehumanization of other women and men. Female participants with different levels of likelihood of conception (LoC) completed a semantic priming paradigm in a lexical decision task. When the word 'woman' was the prime, animal words were more accessible in high versus low LoC whereas human words were more inhibited in the high versus low LoC. When the word 'man' was used as the prime, no difference was found in terms of accessibility between high and low LoC for either animal or human words. These results show that the female dehumanization is automatically elicited by menstrual cycle-related processes and likely associated with an enhanced activation of mate-attraction goals.

  5. Le syndrome d'embolie graisseuse post traumatique

    PubMed Central

    Berdai, Adnane Mohamed; Shimi, Abdelkarim; Khatouf, Mohammed

    2014-01-01

    Le syndrome d'embolie graisseuse est une complication grave des fractures des os longs, il est la conséquence de la dissémination des particules graisseuses dans la microcirculation. L'objectif de ce travail est de déterminer le profil épidémiologique, la présentation clinique et paraclinique de ce syndrome et sa prise en charge thérapeutique. Notre étude porte sur 11 cas de syndrome d'embolie graisseuse colligés au service de réanimation A1 au centre hospitalier universitaire Hassan II de Fès, de Janvier 2009 à Juin 2012. Le diagnostic positif est basé sur les critères de Gurd. Les cas collectés se caractérisent par la prédominance du sexe masculin, d'un âge inférieur à 40 ans, présentant une fracture fémorale. Ce syndrome survient souvent dans les 72 heures après le traumatisme. La présentation clinique est dominée par l'hypoxémie et les troubles de conscience. Sur le plan biologique: l'anémie et la thrombopénie sont les manifestations les plus fréquentes. La prise en charge est symptomatique, 63% des patients ont nécessité l'intubation et la ventilation. L’évolution n'est pas toujours bénigne. Nos résultats confirme le polymorphisme de la présentation clinique et paraclinique du syndrome d'embolie graisseuse. Le diagnostic de ce syndrome se base sur des critères cliniques, mais reste essentiellement un diagnostic d’élimination. La prise en charge est symptomatique. La prévention de ce syndrome est essentielle et se base sur une fixation précoce des fractures des os longs. PMID:25452829

  6. The Geologic Nitrogen Cycle

    NASA Astrophysics Data System (ADS)

    Johnson, B. W.; Goldblatt, C.

    2013-12-01

    N2 is the dominant gas in Earth's atmosphere, and has been so through the majority of the planet's history. Originally thought to only be cycled in significant amounts through the biosphere, it is becoming increasingly clear that a large degree of geologic cycling can occur as well. N is present in crustal rocks at 10s to 100s of ppm and in the mantle at 1s to perhaps 10s of ppm. In light of new data, we present an Earth-system perspective of the modern N cycle, an updated N budget for the silicate Earth, and venture to explain the evolution of the N cycle over time. In an fashion similar to C, N has a fast, biologically mediated cycle and a slower cycle driven by plate tectonics. Bacteria fix N2 from the atmosphere into bioavailable forms. N is then cycled through the food chain, either by direct consumption of N-fixing bacteria, as NH4+ (the primary waste form), or NO3- (the most common inorganic species in the modern ocean). Some organic material settles as sediment on the ocean floor. In anoxic sediments, NH4+ dominates; due to similar ionic radii, it can readily substitute for K+ in mineral lattices, both in sedimentary rocks and in oceanic lithosphere. Once it enters a subduction zone, N may either be volatilized and returned to the atmosphere at arc volcanoes as N2 or N2O, sequestered into intrusive igneous rocks (as NH4+?), or subducted deep into the mantle, likely as NH4+. Mounting evidence indicates that a significant amount of N may be sequestered into the solid Earth, where it may remain for long periods (100s m.y.) before being returned to the atmosphere/biosphere by volcanism or weathering. The magnitude fluxes into the solid Earth and size of geologic N reservoirs are poorly constrained. The size of the N reservoirs contained in the solid Earth directly affects the evolution of Earth's atmosphere. It is possible that N now sequestered in the solid Earth was once in the atmosphere, which would have resulted in a higher atmospheric pressure, and

  7. Simultaneous transgenic suppression of LePG and LeExp1 influences fruit texture and juice viscosity in a fresh market tomato variety.

    PubMed

    Powell, Ann L T; Kalamaki, Mary S; Kurien, Philip A; Gurrieri, Sergio; Bennett, Alan B

    2003-12-03

    Tomatoes are grown for fresh consumption or for processing of the fruit. Some ripening-associated processes of the fruit can either contribute to or degrade attributes associated with both fresh and processing quality. For example, cell wall disassembly is associated with loss of fresh fruit firmness as well as with loss of processed tomato product viscosity. Several enzymes contribute to cell wall polysaccharide disassembly. Polygalacturonase (PG, poly[1,4-alpha-d-galactouronide] glucanohydrolase, EC 3.2.1.15) is among the most abundant polysaccharide hydrolases in ripening tomato fruit and is the major contributor to pectin depolymerization. Expansin (LeExp1) is also abundant in ripening fruit and is proposed to contribute to cell wall disassembly by nonhydrolytic activity, possibly by increasing substrate accessibility to other enzymes. Suppression of either LePG or LeExp1 expression alone results in altered softening and/or shelf life characteristics. To test whether simultaneous suppression of both LePG and LeExp1 expression influences fruit texture in additive or synergistic ways, transgenic Lycopersicon esculentum var. Ailsa Craig lines with reduced expression of either LePG or LeExp1 were crossed. Fruits from the third generation of progeny, homozygous for both transgenic constructs, were analyzed for firmness and other quality traits during ripening on or off the vine. In field-grown transgenic tomato fruit, suppression of LeExp1 or LePG alone did not significantly increase fruit firmness. However, fruits suppressed for both LePG and LeExp1 expression were significantly firmer throughout ripening and were less susceptible to deterioration during long-term storage. Juice prepared from the transgenic tomato fruit with reduced LePG and LeExp1 expression was more viscous than juice prepared from control fruit.

  8. Carbon Cycling with Nuclear Power

    NASA Astrophysics Data System (ADS)

    Lackner, Klaus S.

    2011-11-01

    Liquid hydrocarbon fuels like gasoline, diesel or jet fuel are the most efficient ways of delivering energy to the transportation sector, in particular cars, ships and airplanes. Unfortunately, their use nearly unavoidably leads to the emission of carbon dioxide into the atmosphere. Unless an equivalent amount is removed from the air, the carbon dioxide will accumulate and significantly contribute to the man-made greenhouse effect. If fuels are made from biomass, the capture of carbon dioxide is a natural part of the cycle. Here, we discuss technical options for capturing carbon dioxide at much faster rates. We outline the basic concepts, discuss how such capture technologies could be made affordable and show how they could be integrated into a larger system approach. In the short term, the likely source of the hydrocarbon fuels is oil or gas; in the longer term, technologies that can provide energy to remove oxygen from carbon dioxide and water molecules and combine the remaining components into liquid fuels make it possible to recycle carbon between fuels and carbon dioxide in an entirely abiotic process. Here we focus on renewable and nuclear energy options for producing liquid fuels and show how air capture combined with fuel synthesis could be more economic than a transition to electric cars or hydrogen-fueled cars.

  9. The global water cycle

    NASA Astrophysics Data System (ADS)

    Oki, Taikan; Entekhabi, Dara; Harrold, Timothy Ives

    The global water cycle consists of the oceans, water in the atmosphere, and water in the landscape. The cycle is closed by the fluxes between these reservoirs. Although the amounts of water in the atmosphere and river channels are relatively small, the fluxes are high, and this water plays a critical role in society, which is dependent on water as a renewable resource. On a global scale, the meridional component of river runoff is shown to be about 10% of the corresponding atmospheric and oceanic meridional fluxes. Artificial storages and water withdrawals for irrigation have significant impacts on river runoff and hence on the overall global water cycle. Fully coupled atmosphere-land-river-ocean models of the world's climate are essential to assess the future water resources and scarcities in relation to climate change. An assessment of future water scarcity suggests that water shortages will worsen, with a very significant increase in water stress in Africa. The impact of population growth on water stress is shown to be higher than that of climate change. The virtual water trade, which should be taken into account when discussing the global water cycle and water scarcity, is also considered. The movement of virtual water from North America, Oceania, and Europe to the Middle East, North West Africa, and East Asia represents significant global savings of water. The anticipated world water crisis widens the opportunities for the study of the global water cycle to contribute to the development of sustainability within society and to the solution of practical social problems.

  10. Trimble Vrs Concept

    NASA Astrophysics Data System (ADS)

    Luttenberger, C.

    Presenting the Trimble Virtual Reference Station (VRS) concept. High accuracy Real-Time Kinematic Positioning with GPS is one of todaySs most widely used surveying techniques. But, its use is restricted by the effects of the iono- sphere and troposphere which create systematic errors in the raw data. In practice, these mean that the distance between a rover (mobile) receiver and its reference sta- tion has to be quite short in order to work efficiently. The concept of Virtual Reference Stations offers a new opportunity. When used, the systematic errors in the reference station data are either reduced, or eliminated. This not only allows a user to increase the distance at which the rover receiver is located from the reference, it also increases the reliability of the system and reduces the OTF initialization time. The presentation describes the setup of a VRS system, as well the used model to reduce the error influence in such a permanente reference station network.

  11. Advanced sulfur control concepts

    SciTech Connect

    Harrison, D.P.; Lopez-Ortiz, A.; White, J.D.; Groves, F.R. Jr.

    1995-11-01

    The primary objective of this study is the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Three possible regeneration concepts were identified as a result of a literature search. The potential for elemental sulfur production from a number of candidate metal oxide sorbents using each regeneration concept was evaluated on the basis of a thermodynamic analysis. Two candidate sorbents, Fe{sub 2}O{sub 3} and CeO{sub 2} were chosen for experimental testing. The experimental test program using both electrobalance and fixed-bed reactor sis now getting underway. The objective is to determine reaction conditions--temperature, pressure, space velocity, and regeneration feed gas composition--which will maximize the yield of elemental sulfur in the regeneration product gas. Experimental results are to be used to define a conceptual desulfurization-regeneration process and to provide a preliminary economic evaluation.

  12. Free radical propulsion concept

    NASA Technical Reports Server (NTRS)

    Hawkins, C. E.; Nakanishi, S.

    1981-01-01

    A free radical propulsion concept utilizing the recombination energy of dissociated low molecular weight gases to produce thrust was examined. The concept offered promise of a propulsion system operating at a theoretical impulse, with hydrogen, as high as 2200 seconds at high thrust to power ratio, thus filling the gas existing between chemical and electrostatic propulsion capabilities. Microwave energy used to dissociate a continuously flowing gas was transferred to the propellant via three body recombination for conversion to propellant kinetic energy. Power absorption by the microwave plasma discharge was in excess of 90 percent over a broad range of pressures. Gas temperatures inferred from gas dynamic equations showed much higher temperatures from microwave heating than from electrothermal heating. Spectroscopic analysis appeared to corroborate the inferred temperatures of one of the gases tested.

  13. Cycle Time Task Group

    DTIC Science & Technology

    2004-12-01

    strengths (core competencies) – LEAN manufacturing principles • Creates inventory “pull” system • Reduces Work in Process (WIP) inventory requirements...levels/requirements/rotable parts status and locations • Simplify internal processes and adopt LEAN manufacturing concepts – Highlights supply chain issues

  14. Solar dynamic heat rejection technology. Task 1: System concept development

    NASA Technical Reports Server (NTRS)

    Gustafson, Eric; Carlson, Albert W.

    1987-01-01

    The results are presented of a concept development study of heat rejection systems for Space Station solar dynamic power systems. The heat rejection concepts are based on recent developments in high thermal transport capacity heat pipe radiators. The thermal performance and weights of each of the heat rejection subsystems is addressed in detail, and critical technologies which require development tests and evaluation for successful demonstration are assessed and identified. Baseline and several alternate heat rejection system configurations and optimum designs are developed for both Brayton and Rankine cycles. The thermal performance, mass properties, assembly requirements, reliability, maintenance requirements and life cycle cost are determined for each configuration. A specific design was then selected for each configuration which represents an optimum design for that configuration. The final recommendations of heat rejection system configuration for either the Brayton or Rankine cycles depend on the priorities established for the evaluation criteria.

  15. Modular Reflector Concept Study.

    DTIC Science & Technology

    1981-03-01

    capability provides discretionary backup for direct monitoring and troubleshooting. DCMi MODULE, DEPLOYED DCM MODULE CREW COMPARTMENT MAN IPULATOR MANIPULATOR...are equivalent in size, shape, and function to DCM modules. META modules differ from DCMI modules by having three intermediate struts per module...excluding static loading, which will vary according to mission). As with the DCMI concept, META modules are limited in size by the available diameter

  16. Firefly system concept

    NASA Technical Reports Server (NTRS)

    Nichols, J. D.

    1991-01-01

    The 'Firefly' project has developed and implemented an infrared (IR) remote sensing prototype system based on the concept presented. The Firefly system produces images through smoke that will provide near real-time wildland fire information for fire management and suppression. The prototype will be tested through the 1991 fire season. Results of the testing will be incorporated into the final system design for operational use at the end of 1992.

  17. Some core contested concepts.

    PubMed

    Chomsky, Noam

    2015-02-01

    Core concepts of language are highly contested. In some cases this is legitimate: real empirical and conceptual issues arise. In other cases, it seems that controversies are based on misunderstanding. A number of crucial cases are reviewed, and an approach to language is outlined that appears to have strong conceptual and empirical motivation, and to lead to conclusions about a number of significant issues that differ from some conventional beliefs.

  18. Elaborating on threshold concepts

    NASA Astrophysics Data System (ADS)

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-09-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account for both the important and the problematic characteristics of TCs in terms of the Knowledge/Strategies/Mental Models Framework defined in previous work.

  19. Teaching Angiosperm Reproduction by Means of the Learning Cycle.

    ERIC Educational Resources Information Center

    Scharmann, Lawrence C.

    1991-01-01

    Discussed is an alternative teaching strategy to uncover and assess a common misconception in the life sciences and to articulate its use in teaching a unit on angiosperm reproduction. The learning cycle is described, and a concept map on reproduction on angiosperms is included. (KR)

  20. The continuum of spreading depolarizations in acute cortical lesion development: Examining Leão's legacy.

    PubMed

    Hartings, Jed A; Shuttleworth, C William; Kirov, Sergei A; Ayata, Cenk; Hinzman, Jason M; Foreman, Brandon; Andrew, R David; Boutelle, Martyn G; Brennan, K C; Carlson, Andrew P; Dahlem, Markus A; Drenckhahn, Christoph; Dohmen, Christian; Fabricius, Martin; Farkas, Eszter; Feuerstein, Delphine; Graf, Rudolf; Helbok, Raimund; Lauritzen, Martin; Major, Sebastian; Oliveira-Ferreira, Ana I; Richter, Frank; Rosenthal, Eric S; Sakowitz, Oliver W; Sánchez-Porras, Renán; Santos, Edgar; Schöll, Michael; Strong, Anthony J; Urbach, Anja; Westover, M Brandon; Winkler, Maren Kl; Witte, Otto W; Woitzik, Johannes; Dreier, Jens P

    2016-01-01

    A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed as diffusion restriction in magnetic resonance imaging and define the ischemic core. In delayed lesion growth, transient spreading depolarizations arise spontaneously in the ischemic penumbra and induce further persistent depolarization and excitotoxic damage, progressively expanding the ischemic core. The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion development. These pathophysiologic concepts establish a working hypothesis for translation to human disease, where complex patterns of depolarizations are observed in acute brain injury and appear to mediate and signal ongoing secondary damage.

  1. Water laws and concepts

    USGS Publications Warehouse

    Thomas, H.E.

    1970-01-01

    Throughout human history various laws and customs have developed concerning the individual rights and rights in common to the waters of the earth. Many existing laws and concepts are clearly influenced by the environment in which they originated and reflect the relative abundance or scarcity of water. Many concepts reflect the people's original interests in the water and once established have been passed from generation to generation with little modification. Some laws and concepts have been carried by people in their migrations and colonial expansions to vastly different environments, with rather curious consequences. In many places water laws that had been well adapted to the natural environment have become less tenable because of man's activities in modifying that environment, or because of increasing use of water: Increasing consumptive use shifts the water economy toward lesser abundance or increasing deficiency; increasing nonconsumptive use results in pollution of the water resources, so that they become less suitable for other users. The water-rights systems in the United States vary from State to State: some are reasonably fitted to their environment, some have outlived their place in history, some are wasteful of water, some show favoritism to certain special interests or segments of the population. Water-use rights are universally recognized as real property, with constitutional protection against deprivation without due process of law.

  2. La recherche de naines brunes autour d'etoiles du voisinage solaire et le spectrographe multi-objets SIMON

    NASA Astrophysics Data System (ADS)

    Albert, Loic

    Cette thèse comporte un volet d'instrumentation astronomique, le spectrographe infrarouge SIMON, et un volet de recherche, la recherche de naines brunes autour d'étoiles (lu voisinage solaire. Le premier volet fait état de la construction du Spectrographe infrarouge de Montréal (SIMON), un instrument polyvalent fonctionnant dans le proche infrarouge (0.8-2.5 [mu]m) conçu pour être utilisé à l'Observatoire du mont Mégantic (OMM) et au télescope Canada-France-Hawaii (TCFH). SIMON regroupe plusieurs fonctionnalités: l'irnagerie, la spectroscopie, la spectroscopie rnulti-objets et la polarimétrie. Comme imageur, il offre un champ de vue (le 7.7'x 7.7' à l'OMM et 3.3' x 3.3' au TCFH et possède huit filtres dont un filtre I . SIMON compte trois disperseurs pour la spectroscopie: (1) un prisme d'Amici R max [approximate]50, 0.8-2.5 [mu]m); (2) un grism de silice (R max [approximate]750, 1.17-2.34 [mu]m); et un grism de KRS-5 (R max [approximate]3000, bande J,H ou K S ). Le mode spectroscopique multi-objets utilise des masques cryogéniques placés dans un second cryostat et, couplé au prisme d'Amici, permet l'obtention d'une centaine de spectres simultanément. Le mode polarimétrique permet l'observation de quatre vecteurs de polarisation simultanément. Cette première moitié de thèse étaye les objectifs scientifiques, détaille la conception optique (collimatrice et caméra) et mécanique (un cryostat principal contenant trois cotres à filtres et le détecteur, un cryostat amovible contenant nue roue à masques), décrit l'électronique et le système d'acquisition, et enfin présente les performances dans les différents modes. Le second volet de cette thèse est un relevé grand champ à la recherche de naines brunes de type T autour de 66 étoiles du voisinage solaire. Il a été effectué en utilisant des caméras infrarouges (dont SIMON) et des CCD sur divers télescopes. Le diagramme I--J vs. J--H utilisé est. efficace pour isoler des naines T

  3. Teachers' understanding and the use of the learning cycle

    NASA Astrophysics Data System (ADS)

    Marek, Edmund A.; Eubanks, Carol; Gallaher, Thomas H.

    1990-12-01

    This study examined the relationships that exist between high school science teachers' understanding of the Piagetian developmental model of intelligence, its inherent teaching procedure - the learning cycle - and classroom teaching practices. The teachers observed in this study had expressed dissatisfaction with the teaching methods they used, and, subsequently, attended a National Science Foundation sponsored in-service program designed to examine laboratory-centered science curricula and the educational and scientific theories upon which the curricula were based. The teachers who exhibited a sound understanding of the Piagetian model of intelligence and the learning cycle were more likely to effectively implement learning cycle curricula. They were able to successfully integrate their students' laboratory experiences with class discussions to construct science concepts. The teachers who exhibited misunderstandings of the Piagetian developmental model of intelligence and the learning cycle also engaged their students in laboratory activities, but these activities were weakly related to learning cycles. For example, the data gathered by their students were typically not used in class discussions to construct science concepts. Therefore, these teachers apparently did not discern the necessity of using the data and experiences from laboratory activities as the impetus for science concept attainment. Additional results comparing degrees of understanding, teaching behaviors and questioning strategies are discussed.

  4. Le traitement familial des enfants et des adolescents anorexiques : Des lignes directrices pour le médecin communautaire

    PubMed Central

    Findlay, S; Pinzon, J; Taddeo, D; Katzman, DK

    2010-01-01

    L’anorexie mentale (AM) est une maladie grave qui met la vie en danger et qui fait généralement son apparition pendant l’adolescence. Les données probantes au sujet du traitement optimal de l’AM chez les enfants et les adolescents sont en croissance, mais il reste beaucoup à apprendre. Même si les démarches thérapeutiques actuelles varient au Canada et ailleurs, les données jusqu’à présent indiquent que le traitement familial (TF) est le plus efficace pour les enfants et les adolescents anorexiques. Un élément essentiel du modèle de TF, c’est que les parents sont investis de la responsabilité de rétablir la santé physique de leur enfant et de s’assurer de la reprise complète de son poids. Le médecin qui comprend les principes fondamentaux et la philosophie du TF peut mettre en place les éléments de cette intervention fondée sur des faits probants auprès des jeunes patients anorexiques et de leur famille.

  5. Connecting Instructional and Cognitive Aspects of an LE: A Study of the Global Seminar Project

    ERIC Educational Resources Information Center

    Savelyeva, Tamara

    2012-01-01

    My research problem is based on the lack of unifying conceptual cohesion between the discourses concerning cognitive and instructional aspects of learning environments (LE). I contrast that lack with practical developments of LE studies connected at the level of practical implementation and evaluation. Next, I briefly review the LE boundaries,…

  6. Methodologie de conception numerique d'un ventilateur helico-centrifuge basee sur l'emploi du calcul meridien

    NASA Astrophysics Data System (ADS)

    Lallier-Daniels, Dominic

    La conception de ventilateurs est souvent basée sur une méthodologie « essais/erreurs » d'amélioration de géométries existantes ainsi que sur l'expérience de design et les résultats expérimentaux cumulés par les entreprises. Cependant, cette méthodologie peut se révéler coûteuse en cas d'échec; même en cas de succès, des améliorations significatives en performance sont souvent difficiles, voire impossibles à obtenir. Le projet présent propose le développement et la validation d'une méthodologie de conception basée sur l'emploi du calcul méridien pour la conception préliminaire de turbomachines hélico-centrifuges (ou flux-mixte) et l'utilisation du calcul numérique d'écoulement fluides (CFD) pour la conception détaillée. La méthode de calcul méridien à la base du processus de conception proposé est d'abord présentée. Dans un premier temps, le cadre théorique est développé. Le calcul méridien demeurant fondamentalement un processus itératif, le processus de calcul est également présenté, incluant les méthodes numériques de calcul employée pour la résolution des équations fondamentales. Une validation du code méridien écrit dans le cadre du projet de maîtrise face à un algorithme de calcul méridien développé par l'auteur de la méthode ainsi qu'à des résultats de simulation numérique sur un code commercial est également réalisée. La méthodologie de conception de turbomachines développée dans le cadre de l'étude est ensuite présentée sous la forme d'une étude de cas pour un ventilateur hélico-centrifuge basé sur des spécifications fournies par le partenaire industriel Venmar. La méthodologie se divise en trois étapes: le calcul méridien est employé pour le pré-dimensionnement, suivi de simulations 2D de grilles d'aubes pour la conception détaillée des pales et finalement d'une analyse numérique 3D pour la validation et l'optimisation fine de la géométrie. Les résultats de calcul m

  7. Le carcinome urothélial plasmocytoïde de la vessie : une entité histologique rare au pronostic sombre

    PubMed Central

    Benazzouz, Mohamed Hicham; Essatara, Younes; Elsayegh, Hachem; Iken, Ali; Benslimane, Lounis; Znati, Kaoutar; Nouini, Yassine

    2014-01-01

    Résumé Introduction : Le carcinome urothélial plasmocytoïde est une variante histologique rare du carcinome urothélial. Seule une centaine de cas ont été décrits dans la littérature. Dans cette étude, nous faisons état de deux nouvelles observations. En combinant nos résultats à ceux des différentes séries décrites dans la littérature, nous tentons de définir les caractéristiques cliniques et pathologiques ainsi que l’approche thérapeutique de cette pathologie. Observations : Deux nouveaux cas de carcinome urothélial plasmocytoïde ont été diagnostiqués et pris en charge dans notre établissement. Les 2 patients étaient des hommes de 76 ans en moyenne. L’hématurie était le principal symptôme. Les deux patients ont subi une résection transurétrale de la vessie. Le stade tumoral au moment du diagnostic était avancé dans les deux cas (respectivement T3N0M0 et T3N1M0). Les deux patients ont été traités par cystoprostatectomie. L’analyse histologique de la pièce opératoire, complétée par une étude immunohistochimique, a confirmé le diagnostic de carcinome urothélial plasmocytoïde. Le premier patient est décédé un mois plus tard des suites d’une embolie pulmonaire. Le deuxième patient est décédé au bout de deux mois après avoir reçu deux cycles de chimiothérapie adjuvante. Les données recueillies sur les différentes séries décrites dans la littérature vont dans le même sens que nos données, à savoir un stade avancé au moment du diagnostic et un pronostic sombre. Conclusion : Le carcinome urothélial plasmocytoïde est une variante histologique rare et agressive du carcinome urothélial. Le diagnostic se fait souvent à un stade avancé, et le pronostic est peu encourageant. Le traitement repose le plus souvent sur une cystectomie, suivie d’une chimiothérapie adjuvante à base de cisplatine. L’intérêt d’une chimiothérapie néo-adjuvante n’a pas encore été établi. PMID:25408815

  8. Amélioration du modèle de Preisach. Application aux matériaux magnétiques doux

    NASA Astrophysics Data System (ADS)

    Rousseau, J. J.; Tenant, P.; Zegadi, L.

    1997-08-01

    Magnetic material modeling creates problems particulary when fast, easy to use and accurate models are needed. In this article an investigation of the Preisach model is presented. This model is not really suitable for soft magnetic material with flat loops. A new approach which gives rise to an important improvement of the Preisach model is described. The main properties of the Preisach model are retained. La modélisation des matériaux magnétiques pose de nombreux problèmes, surtout lorsqu'il s'agit d'allier simplicité, rapidité d'exécution et précision. Dans cet article, nous proposons une étude sur le générateur de cycles d'hystérésis de Preisach. Ce modèle s'avère mal adapté aux matériaux magnétiques à cycles d'hystérésis couchés. Nous suggérons une nouvelle approche qui permet d'accroître considérablement la précision du modèle de Preisach tout en conservant ses principales qualités.

  9. Heat pump concepts for industrial use of waste heat

    SciTech Connect

    Blanco, H.P.

    1981-05-01

    Heat pump systems for recovering waste heat are considered. To compare different cycles on a consistent basis, a definition of performance based on the Second Law of Thermodynamics is presented. A high-grade heat-actuated cycle that uses a steam ejector is analyzed, but no substantial development effort is anticipated for implementing heat pumps of this type. Three residual-heat-actuated-heat pumps are analyzed. A turbine-compressor heat pump is presented that can attain relatively high delivery temperatures (approximately 120 to 130/sup 0/C from a source at 60/sup 0/C. The other two residual-heat-actuated concepts presented are absorption heat pumps. One operates on a closed cycle and the other on an open cycle. Delivery temperatures on the order of 115 10 130/sup 0/C with a 60/sup 0/C source are possible, provided that advanced heat/mass transfer configurations are developed. The open-cycle concept is an interesting possibility for heat recovery. It can, in principle, operate with lower waste heat temperatures than a closed cycle, and during the heating season it may provide both process and space heat.

  10. Population exposure from the fuel cycle: Review and future direction

    SciTech Connect

    Richmond, C.R.

    1987-01-01

    The legacy of radiation exposures confronting man arises from two historical sources of energy, the sun and radioactive decay. Contemporary man continues to be dependent on these two energy sources, which include the nuclear fuel cycle. Radiation exposures from all energy sources should be examined, with particular emphasis on the nuclear fuel cycle, incidents such as Chernobyl and Three Mile Island. In addition to risk estimation, concepts such as de minimis, life shortening as a measure of risk, and competing risks as projected into the future must be considered in placing radiation exposures in perspective. The utility of these concepts is in characterizing population exposures for decision makers in a manner that the public may judge acceptable. All these viewpoints are essential in the evaluation of population exposure from the nuclear fuel cycle.

  11. Generalizing about Genre: New Conceptions of an Old Concept.

    ERIC Educational Resources Information Center

    Devitt, Amy J.

    1993-01-01

    Explains the new conception of literary genre as it is being devised in the fields of literary studies, linguistics, and rhetoric. Suggests how this new conception has affected the thinking of teachers on writing and writing instruction. (HB)

  12. Pierre Curie et lele de la symétrie dans les lois physiques

    NASA Astrophysics Data System (ADS)

    de Gennes, P. G.

    Pierre et Jacques Curie découvraient il y a cent ans le phénomène de piézoélectricité : comment un cristal, de suffisamment basse symétrie, développe une polarization lorsqu'il est soumis à une contrainte mécanique. Pierre Curie n'a alors que 21 ans ! Et pourtant ses notes lapidaires aux Comptes Rendus datées de 1880 et 1881 [1] portent en elles tout l'essentiel du phénomène : charges superficielles proportionnelles à la pression, indépendantes de l'épaisseur du cristal, etc. Lorsque quelques mois plus tard, Lippmann prédit l'effet inverse (déformation du crystal sous champ électrique), les frères Curie imaginent tout de suite un dispositif admirablement simple pour détecter ces très faibles déformations. Ils couplent mécaniquement le cristal étudié avec un deuxième cristal piézoélectrique qui joue lele d'un détecteur; ce dernier transforme le signal mécanique du premier cristal en un signal électrique mesuré a l'électromètre ! Les résultats confirment brillamment la prédiction de Lippmann. Et pourtant, les moyens engagés sont très modestes — les champs électriques, par exemple, sont calibrés par la longueur d'une décharge dans l'air…

  13. Drip Shield Emplacement Gantry Concept

    SciTech Connect

    Silva, R.A.; Cron, J.

    2000-03-29

    This design analysis has shown that, on a conceptual level, the emplacement of drip shields is feasible with current technology and equipment. A plan for drip shield emplacement was presented using a Drip Shield Transporter, a Drip Shield Emplacement Gantry, a locomotive, and a Drip Shield Gantry Carrier. The use of a Drip Shield Emplacement Gantry as an emplacement concept results in a system that is simple, reliable, and interfaces with the numerous other exising repository systems. Using the Waste Emplacement/Retrieval System design as a basis for the drip shield emplacement concept proved to simplify the system by using existing equipment, such as the gantry carrier, locomotive, Electrical and Control systems, and many other systems, structures, and components. Restricted working envelopes for the Drip Shield Emplacement System require further consideration and must be addressed to show that the emplacement operations can be performed as the repository design evolves. Section 6.1 describes how the Drip Shield Emplacement System may use existing equipment. Depending on the length of time between the conclusion of waste emplacement and the commencement of drip shield emplacement, this equipment could include the locomotives, the gantry carrier, and the electrical, control, and rail systems. If the exisiting equipment is selected for use in the Drip Shield Emplacement System, then the length of time after the final stages of waste emplacement and start of drip shield emplacement may pose a concern for the life cycle of the system (e.g., reliability, maintainability, availability, etc.). Further investigation should be performed to consider the use of existing equipment for drip shield emplacement operations. Further investigation will also be needed regarding the interfaces and heat transfer and thermal effects aspects. The conceptual design also requires further design development. Although the findings of this analysis are accurate for the assumptions made

  14. Erikson's concept of ego identity reconsidered.

    PubMed

    Wallerstein, R S

    1998-01-01

    This paper explores and attempts to explain the paradox that Erik Erikson--after Freud, undoubtedly the psychoanalyst best known, most deeply esteemed, and most widely influential in the sociohistorical surround of world culture--has at the same time never been properly integrated into the psychoanalytic mainstream, but has instead been marginalized, consigned to a persisting psychoanalytic limbo. Two successive contexts within the historical unfolding of psychoanalysis in America, the milieu in which Erikson worked, would seem to account for this neglect. First, Erikson's monumental contributions to our understanding of the psychosocial developmental process, of the epigenesis of the ego, of the phase-specific developmental tasks across the eight postulated stages of the life cycle, and of the intergenerational cogwheeling of the life cycles were made during the 1950s and 1960s and could not easily be integrated into the ego psychology metapsychological paradigm then monolithically regnant within American psychoanalysis. And, second, as a major paradigm shift took place in America, beginning in the 1970s, toward a more relational, interpersonal, and intersubjective framework, Erikson's contributions, couched as they were in the structural language of the ego psychology of his time, were overlooked and went unremarked as seminal precursors of the newly emerging emphases. The clear relationship of Erikson's concepts of (ego) identity to emerging conceptions of self in relation to objects was simply not noticed, and his work continues to this day to be neglected and unintegrated within psychoanalysis.

  15. Re-evaluation of monitored retrievable storage concepts

    SciTech Connect

    Fletcher, J.F.; Smith, R.I.

    1989-04-01

    In 1983, as a prelude to the monitored retrievable storage (MRS) facility conceptual design, the Pacific Northwest Laboratory (PNL) conducted an evaluation for the US Department of Energy (DOE) that examined alternative concepts for storing spent LWR fuel and high- level wastes from fuel reprocessing. The evaluation was made considering nine concepts for dry away-from-reactor storage. The nine concepts evaluated were: concrete storage cask, tunnel drywell, concrete cask-in-trench, open-cycle vault, metal casks (transportable and stationary), closed-cycle vault, field drywell, and tunnel-rack vault. The purpose and scope of the re-evaluation did not require a repetition of the expert-based examinations used earlier. Instead, it was based on more detailed technical review by a small group, focusing on changes that had occurred since the initial evaluation was made. Two additional storage concepts--the water pool and the horizontal modular storage vault (NUHOMS system)--were ranked along with the original nine. The original nine concepts and the added two conceptual designs were modified as appropriate for a scenario with storage capacity for 15,000 MTU of spent fuel. Costs, area requirements, and technical and historical data pertaining to MRS storage were updated for each concept.

  16. Archaea in biogeochemical cycles.

    PubMed

    Offre, Pierre; Spang, Anja; Schleper, Christa

    2013-01-01

    Archaea constitute a considerable fraction of the microbial biomass on Earth. Like Bacteria they have evolved a variety of energy metabolisms using organic and/or inorganic electron donors and acceptors, and many of them are able to fix carbon from inorganic sources. Archaea thus play crucial roles in the Earth's global geochemical cycles and influence greenhouse gas emissions. Methanogenesis and anaerobic methane oxidation are important steps in the carbon cycle; both are performed exclusively by anaerobic archaea. Oxidation of ammonia to nitrite is performed by Thaumarchaeota. They represent the only archaeal group that resides in large numbers in the global aerobic terrestrial and marine environments on Earth. Sulfur-dependent archaea are confined mostly to hot environments, but metal leaching by acidophiles and reduction of sulfate by anaerobic, nonthermophilic methane oxidizers have a potential impact on the environment. The metabolisms of a large number of archaea, in particular those dominating the subsurface, remain to be explored.

  17. Stirling cycle cryogenic cooler

    NASA Technical Reports Server (NTRS)

    Gasser, M. G.; Sherman, A.; Studer, P. A.; Daniels, A.; Goldowsky, M. P. (Inventor)

    1983-01-01

    A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications is described. It consists of a compressor section centrally aligned end to end with an expansion section, and respectively includes a reciprocating compressor piston and displacer radially suspended in interconnecting cylindrical housings by active magnetic bearings and has adjacent reduced clearance regions so as to be in noncontacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston and displacer are reciprocated in their housings by linear drive motors to vary the volume of respectively adjacent compression and expansion spaces which contain a gaseous working fluid and a thermal regenerator to effect Stirling cycle cryogenic cooling.

  18. The Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Wigley, T. M. L.; Schimel, D. S.

    2005-08-01

    Reducing carbon dioxide (CO2) emissions is imperative to stabilizing our future climate. Our ability to reduce these emissions combined with an understanding of how much fossil-fuel-derived CO2 the oceans and plants can absorb is central to mitigating climate change. In The Carbon Cycle, leading scientists examine how atmospheric carbon dioxide concentrations have changed in the past and how this may affect the concentrations in the future. They look at the carbon budget and the "missing sink" for carbon dioxide. They offer approaches to modeling the carbon cycle, providing mathematical tools for predicting future levels of carbon dioxide. This comprehensive text incorporates findings from the recent IPCC reports. New insights, and a convergence of ideas and views across several disciplines make this book an important contribution to the global change literature.

  19. The microbial nitrogen cycle.

    PubMed

    Jetten, Mike S M

    2008-11-01

    This special issue highlights several recent discoveries in the microbial nitrogen cycle including the diversity of nitrogen-fixing bacteria in special habitats, distribution and contribution of aerobic ammonium oxidation by bacteria and crenarchaea in various aquatic and terrestrial ecosystems, regulation of metabolism in nitrifying bacteria, the molecular diversity of denitrifying microorganisms and their enzymes, the functional diversity of freshwater and marine anammox bacteria, the physiology of nitrite-dependent anaerobic methane oxidation and the degradation of recalcitrant organic nitrogen compounds. Simultaneously the articles in this issue show that many questions still need to be addressed, and that the microbes involved in catalyzing the nitrogen conversions still harbour many secrets that need to be disclosed to fully understand the biogeochemical nitrogen cycle, and make future predictions and global modelling possible.

  20. Experimental implementation of automatic 'cycle to cycle' control to a nonlinear chiral simulated moving bed separation.

    PubMed

    Grossmann, Cristian; Langel, Christian; Mazzotti, Marco; Morari, Manfred; Morbidelli, Massimo

    2010-03-26

    In order to better exploit the economic potential of the simulated moving bed chromatography a 'cycle to cycle' controller which only requires the information about the linear adsorption behavior and the overall average porosity of the columns has been proposed. Recently, an automated on-line HPLC monitoring system which determines the concentrations in the two product streams averaged over one cycle, and returns them as feedback information to the controller was implemented. The new system allows for an accurate determination of the average concentration of the product streams even if the plant is operated at high concentrations. This paper presents the experimental implementation of the 'cycle to cycle' control concept to the separation of guaifenesin enantiomers under nonlinear chromatographic conditions, i.e. at high feed concentrations. Different case studies have been carried out to challenge the controller under realistic operation conditions, e.g. introducing pump disturbances and changing the feed concentration during the operation. The experimental results clearly demonstrate that the controller can indeed deliver the specified purities and improve the process performance.

  1. Investigating alternative conceptions in learning disabled students

    NASA Astrophysics Data System (ADS)

    Cole, Terry Stokes

    Science teachers have long noticed the fact that their students come to school with their own concepts, produced from daily experiences and interactions with the world around them. Sometimes these ideas are in agreement with accepted scientific theories, but often they are not. These "incorrect" ideas, or "misconceptions" have been the focus of many studies, which can be helpful to teachers when planning their lessons. However, there is a dearth of information that is geared specifically to students with learning disabilities. These students generally have deficits in areas of perception and learning that could conceivably influence the way they formulate concepts. The purpose of this study was to examine the concepts held by students with learning disabilities on the causes of the day/night cycle, the phases of the moon, and the seasons. An interview format was judged to be the best method of ensuring that the students' ideas were clearly documented. The subjects were five, sixth-grade students in a city school, who had been determined to have a learning disability. In examining the results, there did not seem to be any direct link between the type of misconception formed and the learning deficit of the child. It seemed more likely that students formed their concepts the way students usually do, but the various disabilities they exhibited interfered with their learning of more appropriate conceptions. The results of this study will be helpful to science teachers, curriculum planners, or anyone who works with students who have learning disabilities. It is hoped that this will begin to fill a void in the area of learning disabilities research.

  2. [Microbial geochemical calcium cycle].

    PubMed

    Zavarzin, G A

    2002-01-01

    The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites.

  3. Stirling cycle engine

    DOEpatents

    Lundholm, Gunnar

    1983-01-01

    In a Stirling cycle engine having a plurality of working gas charges separated by pistons reciprocating in cylinders, the total gas content is minimized and the mean pressure equalization among the serial cylinders is improved by using two piston rings axially spaced at least as much as the piston stroke and by providing a duct in the cylinder wall opening in the space between the two piston rings and leading to a source of minimum or maximum working gas pressure.

  4. Nuclear Fuel Cycle

    SciTech Connect

    Dale, Deborah J.

    2014-10-28

    These slides will be presented at the training course “International Training Course on Implementing State Systems of Accounting for and Control (SSAC) of Nuclear Material for States with Small Quantity Protocols (SQP),” on November 3-7, 2014 in Santa Fe, New Mexico. The slides provide a basic overview of the Nuclear Fuel Cycle. This is a joint training course provided by NNSA and IAEA.

  5. The carbon dioxide cycle

    USGS Publications Warehouse

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  6. Gondwanaland's seasonal cycle

    NASA Technical Reports Server (NTRS)

    Crowley, Thomas J.; Short, David A.; Mengel, John G.

    1987-01-01

    A two-dimensional energy balance climate model has been used to simulate the seasonal temperature cycle on a supercontinent-sized land mass. Experiments with idealized and realistic geography indicate that the land-sea configuration in high latitudes exerts a strong influence on the magnitude of summer warming. These simulations provide significant insight into the evolution of climate during the Palaeozoic, and raise questions about the presumed pre-eminent role of carbon dioxide in explaining long-term climate change.

  7. Space Mission Concept Development Using Concept Maturity Levels

    NASA Technical Reports Server (NTRS)

    Wessen, Randii R.; Borden, Chester; Ziemer, John; Kwok, Johnny

    2013-01-01

    Over the past five years, pre-project formulation experts at the Jet Propulsion Laboratory (JPL) has developed and implemented a method for measuring and communicating the maturity of space mission concepts. Mission concept development teams use this method, and associated tools, prior to concepts entering their Formulation Phases (Phase A/B). The organizing structure is Concept Maturity Level (CML), which is a classification system for characterizing the various levels of a concept's maturity. The key strength of CMLs is the ability to evolve mission concepts guided by an incremental set of assessment needs. The CML definitions have been expanded into a matrix form to identify the breadth and depth of analysis needed for a concept to reach a specific level of maturity. This matrix enables improved assessment and communication by addressing the fundamental dimensions (e.g., science objectives, mission design, technical risk, project organization, cost, export compliance, etc.) associated with mission concept evolution. JPL's collaborative engineering, dedicated concept development, and proposal teams all use these and other CML-appropriate design tools to advance their mission concept designs. This paper focuses on mission concept's early Pre-Phase A represented by CMLs 1- 4. The scope was limited due to the fact that CMLs 5 and 6 are already well defined based on the requirements documented in specific Announcement of Opportunities (AO) and Concept Study Report (CSR) guidelines, respectively, for competitive missions; and by NASA's Procedural Requirements NPR 7120.5E document for Projects in their Formulation Phase.

  8. Self-Concept Is a Concept Worth Considering

    ERIC Educational Resources Information Center

    Shields, Nora

    2009-01-01

    There is a growing recognition of the importance of self-concept in the pediatric rehabilitation research literature. There also is confusion and inconsistency in the definitions of and the terminology used to describe self-concept. What is agreed is that self-concept is multidimensional, comprising a child's perception of their personal…

  9. Children's understanding of additive concepts.

    PubMed

    Robinson, Katherine M; Dubé, Adam K; Beatch, Jacqueline-Ann

    2017-04-01

    Most research on children's arithmetic concepts is based on one concept at a time, limiting the conclusions that can be made about how children's conceptual knowledge of arithmetic develops. This study examined six arithmetic concepts (identity, negation, commutativity, equivalence, inversion, and addition and subtraction associativity) in Grades 3, 4, and 5. Identity (a-0=a) and negation (a-a=0) were well understood, followed by moderate understanding of commutativity (a+b=b+a) and inversion (a+b-b=a), with weak understanding of equivalence (a+b+c=a+[b+c]) and associativity (a+b-c=[b-c]+a). Understanding increased across grade only for commutativity and equivalence. Four clusters were found: The Weak Concept cluster understood only identity and negation; the Two-Term Concept cluster also understood commutativity; the Inversion Concept cluster understood identity, negation, and inversion; and the Strong Concept cluster had the strongest understanding of all of the concepts. Grade 3 students tended to be in the Weak and Inversion Concept clusters, Grade 4 students were equally likely to be in any of the clusters, and Grade 5 students were most likely to be in the Two-Term and Strong Concept clusters. The findings of this study highlight that conclusions about the development of arithmetic concepts are highly dependent on which concepts are being assessed and underscore the need for multiple concepts to be investigated at the same time.

  10. Reversible Cycling of Silicon and Silicon Alloys

    NASA Astrophysics Data System (ADS)

    Obrovac, Mark

    2012-02-01

    Lithium ion batteries typically use a graphite negative electrode. Silicon can store more lithium than any other element and has long been considered as an attractive replacement for graphite. The theoretical lithium storage capacity of silicon is nearly ten times higher than graphite volumetrically and three times higher gravimetrically. The equilibrium Si-Li binary system is well known. Completely new phase behaviors are observed at room temperature. This includes the formation of a new phase, Li15Si4, which is the highest lithium containing phase at room temperature [1]. The formation of Li15Si4 is accompanied by a 280 percent volume expansion of silicon. During de-alloying this phase contracts, forming amorphous silicon. The volume expansion of alloys can cause intra-particle fracture and inter-particle disconnection; leading to loss of cycle life. To overcome issues with volume expansion requires a detailed knowledge of Li-Si phase behavior, careful design of the composition and nanostructure of the alloy and the microstructure of the negative electrode [2]. In this presentation the phase behavior of the Li-Si system will be described. Using this knowledge alone, strategies can be developed so that silicon can be reversibly cycled in a battery hundreds of times. Further increases in energy density and efficiency can be gained by alloying silicon with other elements, while controlling microstructure [2]. Coupled with negative electrode design strategies, practical negative electrodes for lithium ion cells can be developed based on bulk materials, with significant energy density improvement over conventional electrodes. [4pt] [1] M.N. Obrovac and L.J. Krause, J. Electrochem. Soc., 154 (2007) A103. [0pt] [2] M.N. Obrovac, Leif Christensen, Dinh Ba Le, and J.R. Dahn, J. Electrochem. Soc., 154 (2007) A849

  11. The integral fast reactor (IFR) concept: Physics of operation and safety

    SciTech Connect

    Wade, D.C.; Chang, Y.I.

    1987-01-01

    The IFR concept employs a pool layout, a U/Pu/Zr metal alloy fuel and a closed fuel cycle based on pyrometallurgical reprocessing and injection casting refabrication. The reactor physics issues of designing for inherent safety and for a closed fissile self-sufficient integral fuel cycle with uranium startup and potential actinide transmutation are discussed.

  12. RADAR "SAIL" satellite concept

    NASA Astrophysics Data System (ADS)

    Aguttes, Jean Paul; Sombrin, Jacques; Conde, Eric

    1996-11-01

    The Radar SAIL concept is based on the use of a rectangular antenna lying in the dawn-dusk orbital plane with the length (along speed vector) smaller than the height. Such geometry makes it possible to place the solar cells on the back of the antenna, to use gravity gradient stabilisation, and to implement multipath-free GPS interferometric measurement of the antenna deformation thus allowing structural relaxation. Less obviously, the geometry favours the RADAR design too, by allowing grating lobes and therefore a lower density of built-in electronic in the active antenna. The antenna can be thin and packed for launch inside a cylinder-shaped bus having pyrotechnic doors for the antenna deployement and bearing the rest of the payload and the service equipment. With respect to a standard design of performant missions, cost savings come from the bus, whose functions (AOCS, power supply) are simplified, from the launch since the mass budget and the stowing configuration become compatible with medium size rockets (LLV2/3, DELTA-LITE, LM-4.), and from the active antenna built-in electronics. The RADAR SAIL concept is all the more cost effective when the mission requires a large, high and short antenna, i.e. high resolution (<5m), low frequency band (L or S or even P), high revisiting, multiple frequencies. Mission implementation and funding can be favored by the new capability to share the satellite between autonomous regional operators. Combined with ground DBF (digital beam forming) technique, the concept allows extremely simple and low cost missions providing a fixed wide swath (10 to 15 m resolution within 500km to 1000 km swath) for systematic surveillance or monitoring.

  13. GLAST Mission Concept Study

    NASA Technical Reports Server (NTRS)

    Cominsky, Lynn R.

    2001-01-01

    Cominsky served as the chair of the GLAST Public Affairs Working Group during the mission concept study. The major accomplishments of this group, which were carried out under her direction include: (1) GLAST Outreach website; (2) Brochure for scientists; (3) Brochure for public; (4) Developed the five key science goal 'bullets' to explain GLAST to the public, as well as the motto used on the GLAST brochures 'Quest for the Ultimate Sources of Energy in the Universe'; (5) Defined the EPO program for GLAST for the proposal phase. Developed initial program outline and budget; and (6) Assisted in the development of the GLAST exhibit, which was used at several scientific conferences.

  14. On the gestalt concept.

    PubMed

    Breidbach, Olaf; Jost, Jürgen

    2006-08-01

    We define a gestalt as the invariants of a collection of patterns that can mutually be transformed into each other through a class of transformations encoded by, or conversely, determining that gestalt. The class of these transformations needs to satisfy structural regularities like the ones of the mathematical structure of a group. This makes an analysis of a gestalt possible in terms of relations between its representing patterns. While the gestalt concept has its origins in cognitive psychology, it has also important implications for morphology.

  15. The concept behind sugammadex.

    PubMed

    Epemolu, O; Bom, A

    2014-05-01

    Sugammadex is the first selective relaxant binding agent. It allows rapid reversal of any degree of neuromuscular blockade induced by steroidal neuromuscular blocking agents. Sugammadex acts by encapsulation of the neuromuscular blocking agent. This prevents the drug from acting on prejunctional and postjunctional nicotinic receptors, allowing acetylcholine to activate these receptors, and resulting in reversal of the neuromuscular blockade. Objective monitoring of the degree of neuromuscular blockade is strongly recommended to determine the optimal dose of sugammadex. A good understanding of the concept behind sugammadex is essential in order to use this reversal agent in clinical practice.

  16. Indian concepts on sexuality

    PubMed Central

    Chakraborty, Kaustav; Thakurata, Rajarshi Guha

    2013-01-01

    India is a vast country depicting wide social, cultural and sexual variations. Indian concept of sexuality has evolved over time and has been immensely influenced by various rulers and religions. Indian sexuality is manifested in our attire, behavior, recreation, literature, sculptures, scriptures, religion and sports. It has influenced the way we perceive our health, disease and device remedies for the same. In modern era, with rapid globalization the unique Indian sexuality is getting diffused. The time has come to rediscover ourselves in terms of sexuality to attain individual freedom and to reinvest our energy to social issues related to sexuality. PMID:23858263

  17. Mars rover 1988 concepts

    NASA Technical Reports Server (NTRS)

    Pivirotto, Donna Shirley; Penn, Thomas J.; Dias, William C.

    1989-01-01

    Results of FY88 studies of a sample-collecting Mars rover are presented. A variety of rover concepts are discussed which include different technical approaches to rover functions. The performance of rovers with different levels of automation is described and compared to the science requirement for 20 to 40 km to be traversed on the Martian surface and for 100 rock and soil samples to be collected. The analysis shows that a considerable amount of automation in roving and sampling is required to meet this requirement. Additional performance evaluation shows that advanced RTG's producing 500 W and 350 WHr of battery storage are needed to supply the rover.

  18. Open airscrew VTOL concepts

    NASA Technical Reports Server (NTRS)

    Stepniewski, W. Z.; Tarczynski, T.

    1992-01-01

    The following concepts, based on using open airscrew(s) for VTOL maneuvers, are re-examined in light of current technology: (1) tip-driven helicopters, (2) compound helicopters; and (3) high-speed VTOL aircraft, represented by tiltrotors, tiltwings, retractoplanes and stoppable rotors. Criteria, permitting one to compare performance of aircraft using diverse lifting and propelling methods are established. Determination of currently possible performance, indication of near-future potentials, and comparison of those items with the baseline levels (as represented by contemporary shaft-driven helicopters, first generation tiltrotors, and commercial turboprop fixed-wind aircraft) constitutes bulk of this report.

  19. Terrestrial Carbon Cycle Variability.

    PubMed

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y (-1)) with respect to a large and uncertain background (123 +/- 4 Pg-C y (-1)), and

  20. Terrestrial Carbon Cycle Variability

    PubMed Central

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1), and