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. The Molar Concept: A Piagetian-Oriented Learning Cycle.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.; Perry, Constance M.

    1983-01-01

    The Mole Concept is a learning cycle (patterned after University of Nebraska-Lincoln's ADAPT model) for the chemical unit "mole." Discusses objectives and activities involved in each phase of the cycle: exploration, invention, and application. Indicates the cycle is superior to traditional lecture-demonstration for teaching the abstract mole…

  3. 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

  4. 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

  5. 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.

  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. Concepts associated with a unified life cycle analysis

    SciTech Connect

    Whelan, Gene; Peffers, Melissa S.; Tolle, Duane A.; Brebbia, C. A.; Almorza Gomar, D.; Klapperich, H.

    2002-01-01

    There is a risk associated with most things in the world, and all things have a life cycle unto themselves, even brownfields. Many components can be described by a''cycle of life.'' For example, five such components are life-form, chemical, process, activity, and idea, although many more may exist. Brownfields may touch upon several of these life cycles. Each life cycle can be represented as independent software; therefore, a software technology structure is being formulated to allow for the seamless linkage of software products, representing various life-cycle aspects. Because classes of these life cycles tend to be independent of each other, the current research programs and efforts do not have to be revamped; therefore, this unified life-cycle paradigm builds upon current technology and is backward compatible while embracing future technology. Only when two of these life cycles coincide and one impacts the other is there connectivity and a transfer of information at the interface. The current framework approaches (e.g., FRAMES, 3MRA, etc.) have a design that is amenable to capturing (1) many of these underlying philosophical concepts to assure backward compatibility of diverse independent assessment frameworks and (2) linkage communication to help transfer the needed information at the points of intersection. The key effort will be to identify (1) linkage points (i.e., portals) between life cycles, (2) the type and form of data passing between life cycles, and (3) conditions when life cycles interact and communicate. This paper discusses design aspects associated with a unified life-cycle analysis, which can support not only brownfields but also other types of assessments.

  8. 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. PMID:22490937

  9. 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.

  10. 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

  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. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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)

  18. A Concept of An Accelerator Closed Nuclear Fuel Cycle

    NASA Astrophysics Data System (ADS)

    Eremeev, I. P.

    1997-05-01

    The physical approach (I.P.Eremeev. Proc. of the PAC-95. Vol.1, p.98.) is applied for technology of nuclear fuel cycle. It is proposed the cycle to be closed by such an accelerator based process link, which would allow, on the one hand, the most hazardous of "equilibrium" radionuclides to be transmuted to stable isotopes or incinerated and, on the other hand, additional fissile fuel to be produced to compensate the energy consumption. Parameters of the technology, such as an intensity and energy "cost" of a transmutation event, a flux of photoneutrons produced have been determined for model targets. It is shown that the approach allows the above fission/transuranium radionuclides to be transmuted/ incinerated at a much greater rate than that of their build-up in operating NPP reactors at a much less energy consumption than an energy produced under their formation and at considerable compensation of the consumed energy through breeding fissile isotopes. A possibility of going to a closed Th-U fuel cycle is discussed. To realize the technology proposed requirements to a system of electron accelerators are formulated.

  19. 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…

  20. 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…

  1. 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

  2. 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).

  3. La silice et le cycle du carbone dans l'océan

    NASA Astrophysics Data System (ADS)

    Tréguer, Paul

    2002-01-01

    Silicon is a key element whose major role in the control of the cycle of carbon in the ocean has been recently revealed. This is first illustrated through the resolution of the 'opal paradox' in the modern Southern Ocean. Second, the 'silica hypothesis' explains why, during the Last Glacial Maximum, the atmospheric concentration of CO 2 was about 40 % below that of the interglacial period. Increased deliveries of wind-borne silica to the surface ocean as well as of riverine inputs favoured the dominance of diatoms over coccolithophorids, resulting in a net emission decrease of CO 2 by coccolithophorids from the ocean surface to the atmosphere. To cite this article: P. Tréguer, C. R. Geoscience 334 (2002) 3-11

  4. 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…

  5. Advanced fusion MHD power conversion using the CFAR (compact fusion advanced Rankine) cycle concept

    SciTech Connect

    Hoffman, M.A.; Campbell, R.; Logan, B.G.; Lawrence Livermore National Lab., CA )

    1988-10-01

    The CFAR (compact fusion advanced Rankine) cycle concept for a tokamak reactor involves the use of a high-temperature Rankine cycle in combination with microwave superheaters and nonequilibrium MHD disk generators to obtain a compact, low-capital-cost power conversion system which fits almost entirely within the reactor vault. The significant savings in the balance-of-plant costs are expected to result in much lower costs of electricity than previous concepts. This paper describes the unique features of the CFAR cycle and a high- temperature blanket designed to take advantage of it as well as the predicted performance of the MHD disk generators using mercury seeded with cesium. 40 refs., 8 figs., 3 tabs.

  6. 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.

  7. Concept for a small, colocated fuel cycle facility for oxide breeder fuels

    SciTech Connect

    Burch, W.D.; Stradley, J.G.; Lerch, R.E.

    1987-01-01

    As part of a United States Department of Energy (USDOE) program to examine innovative liquid-metal reactor (LMR) system designs over the past three years, the Oak Ridge National Laboratory (ORNL) and the Westinghouse Hanford Company (WHC) collaborated on studies of mixed oxide fuel cycle options. A principal effort was an advanced concept for a small integrated fuel cycle colocated with a 1300-MW(e) reactor station. The study provided a scoping design and a basis on which to proceed with implementation of such a facility if future plans so dictate. The facility integrated reprocessing, waste management, and refabrication functions in a single facility of nominal 35-t/year capacity utilizing the latest technology developed in fabrication programs at WHC and in reprocessing at ORNL. The concept was based on many years of work at both sites and extensive design studies of prior years.

  8. Concept for a small, colocated fuel cycle facility for oxide breeder fuels

    SciTech Connect

    Burch, W.D.; Lerch, R.E.; Stradley, J.G.

    1987-01-01

    As part of a United States Department of Energy (USDOE) program to examine innovative liquid-metal reactor (LMR) system designs over the past three years, the Oak Ridge National Laboratory (ORNL) and the Westinghouse Hanford Company (WHC) collaborated on studies of mixed oxide fuel cycle options. A principal effort was an advanced concept for a small integrated fuel cycle colocated with a 1300-MW(e) reactor station. The study provided a scoping design, capital and operating cost estimates, and a basis on which to proceed with implementation of such a facility if future plans so dictate. The facility integrated reprocessing, waste management, and refabrication functions in a single facility of nominal 35-t/year capacity utilizing the latest technology developed in fabrication programs at WHC and in reprocessing at ORNL. The concept was based on many years of work at both sites and extensive design studies of prior years.

  9. 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)

  10. 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.

  11. Review of open-cycle desiccant air-conditioning concepts and systems

    SciTech Connect

    Wurm, J.

    1986-08-01

    This paper attempts to overview the development status of desiccant cooling. Over the past 30 years of progressively intensifying attention, this promising technology has become a domain of interest of many research agencies and manufacturing companies. As a result, the market potential for machines based on desiccant processes, particularly in comfort cooling and agricultural applications, is getting close to realization. One of the most important incentives of developing heat-activated, open-cycle desiccant cooling machines (air conditioners) has always been its potential simplicity. Such premise has been deceiving to a degree that in many instances has slowed the progress. However, the persistent analytical and material research brought some desiccant systems close to the marketplace. They provide attractive alternatives to consumers and utilities, offering particularly effective humidity and temperature control in cases of high fresh-air-makeup requirements. The control of bacteria, airborne particulates, as well as CO/sub 2/, combined with effective heating capability make them attractive for controlled-atmosphere agriculture. Finally, the capability of using low-temperature waste heat to drive the cycle becomes an important attribute of a desiccant concept, specifically when combined with a regular vapor-compression cooling machine in energy saving space-conditioning concepts. The presented assessment concludes that, particularly for specialized applications, machines based on open-cycle desiccant cooling processes are very close to playing an important role in the space-conditioning (including comfort control) marketplace.

  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. [Microsatellites or the eukaryotic genome: life cycle concept and neutrality issues].

    PubMed

    Balaresque, Patricia

    2007-01-01

    Microsatellite markers have a great discriminating power. Widely exploited in many disciplines such as forensic science, medical genetics, conservation biology and molecular ecology, they are also used in human population genetics to illuminate our origins. However, strikingly, their fundamental evolutionary mechanisms remain obscure, because of the difficulty of disentangling the complex and numerous factors involved. After a brief summary of their basic characteristics, the concept of life cycle size-dependant is explored. The major mechanisms known to explain the four different phases of their life (conception, birth, growing and senescence/renaissance) are discussed. Emerging questions about their neutrality are also investigated, pointing out a real need to improve our understanding of their mutational dynamics.

  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. 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

  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. 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

  3. 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.

  4. The concept of vulnerability within the disaster management cycle - A geospatial perspective

    NASA Astrophysics Data System (ADS)

    Aubrecht, Christoph; Freire, Sérgio; Kienberger, Stefan; Steinnocher, Klaus; Zeil, Peter

    2010-05-01

    This paper illustrates the concept of vulnerability within the disaster management cycle from a geospatial perspective. Disaster management is widely regarded as a cyclic multi-stage concept starting with (1) a response phase after a disaster strikes, followed by (2) risk analysis and (3) mitigation efforts to minimize the impacts of future disasters. Different types of hazards such as hurricanes, tsunamis, floods, earthquakes and fires feature individual characteristics and require adapted actions in all three stages mentioned above. From a general point of view the phase of response includes first-pass impact assessment and accordingly coordinated search and rescue efforts as well as follow-on recovery and rehabilitation. Mitigating impacts of disasters starts with risk reduction and prevention measurements whereas land use management plays an important role as well as general preparedness both in terms of social and economic activities and infrastructural measures. Prediction and early warning preceding the next hazard event form the final part of this phase and at the same time start the next run of the disaster management cycle. Risk assessment as an integral part of disaster management is composed of hazard and vulnerability analysis. Most aspects of hazard investigations have a spatial component whereas both Earth Observation data and terrestrial surveys provide essential information for delineation of potentially affected areas and monitoring influencing environmental conditions. The mere incidence of a natural event does not necessarily cause negative effects, e.g. wildfires are actually an important factor for ecosystem stability and recurring flooding often benefits riparian forests and agricultural areas. The term disaster is thus not used until impacts on social systems including human beings and associated assets (i.e. economic, infrastructural) are caused. This is where the concept of vulnerability comes into play which is defined by a set of

  5. 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…

  6. Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost--Supplement. Final Report.

    ERIC Educational Resources Information Center

    Goclowski, John C.; And Others

    This supplement to a technical report providing the results of a preliminary investigation of the potential impact of the Digital Avionics Information System (DAIS) concept on system support personnel requirements and life cycle cost (LCC) includes: (1) additional details of the cost comparison of a hypothetical application of a conceptual…

  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. 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.

  11. 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.

  12. 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.

  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. Thermodynamic limits of hydrologic cycling within the Earth system: concepts, estimates and implications

    NASA Astrophysics Data System (ADS)

    Kleidon, A.; Renner, M.

    2013-03-01

    The hydrologic cycle results from the combination of energy conversions and atmospheric transport, and the laws of thermodynamics set limits to both. Here, we apply thermodynamics to derive the limits of the strength of hydrologic cycling within the Earth system and the properties and processes that shape these limits. We set up simple models to derive analytical expressions of the limits of evaporation and precipitation in relation to vertical and horizontal differences in solar radiative forcing. These limits result from a fundamental trade-off by which a greater evaporation rate reduces the temperature gradient and thus the driver for atmospheric motion that exchanges moistened air from the surface with the drier air aloft. The limits on hydrologic cycling thus reflect the strong interaction between the hydrologic flux, motion, and the driving gradient. Despite the simplicity of the models, they yield estimates for the limits of hydrologic cycling that are within the observed magnitude, suggesting that the global hydrologic cycle operates near its maximum strength. We close with a discussion of how thermodynamic limits can provide a better characterization of the interaction of vegetation and human activity with hydrologic cycling.

  15. Thermodynamic limits of hydrologic cycling within the Earth system: concepts, estimates and implications

    NASA Astrophysics Data System (ADS)

    Kleidon, A.; Renner, M.

    2013-07-01

    The hydrologic cycle results from the combination of energy conversions and atmospheric transport, and the laws of thermodynamics set limits to both. Here, we apply thermodynamics to derive the limits of the strength of hydrologic cycling within the Earth system and about the properties and processes that shape these limits. We set up simple models to derive analytical expressions of the limits of evaporation and precipitation in relation to vertical and horizontal differences in solar radiative forcing. These limits result from a fundamental trade-off by which a greater evaporation rate reduces the temperature gradient and thus the driver for atmospheric motion that exchanges moistened air from the surface with the drier air aloft. The limits on hydrologic cycling thus reflect the strong interaction between the hydrologic flux, motion, and the driving gradient. Despite the simplicity of the models, they yield estimates for the limits of hydrologic cycling that are within the observed magnitude, suggesting that the global hydrologic cycle operates near its maximum strength. We close with a discussion of how thermodynamic limits can provide a better characterization of the interaction of vegetation and human activity with hydrologic cycling.

  16. 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.

  17. 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.

  18. Addressing Student Difficulties with Concepts Related to Entropy, Heat Engines and the Carnot Cycle

    NASA Astrophysics Data System (ADS)

    Smith, Trevor I.; Christensen, Warren M.; Thompson, John R.

    2009-11-01

    We report the rationale behind and preliminary results from a guided-inquiry conceptual worksheet (a.k.a. tutorial) dealing with Carnot's efficiency and the Carnot cycle. The tutorial was administered in an upper-level thermodynamics course at the University of Maine. The tutorial was implemented as the third in a three-tutorial sequence designed to improve students' understanding of entropy and its applications. Initial pre- and post-tutorial assessment data suggest that student understanding of heat engines and the Carnot cycle improved as a result of tutorial instruction.

  19. 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.

  20. Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost. Final Report.

    ERIC Educational Resources Information Center

    Goclowski, John C.; And Others

    Designed to identify and quantify the potential impacts of the Digital Avionics Information System (DAIS) on weapon system personnel requirements and life cycle cost (LCC), this study postulated a typical close-air-support (CAS) mission avionics suite to serve as a basis for comparing present day and DAIS configuration specifications. The purpose…

  1. An Assessment of Students' Understanding of Ecosystem Concepts: Conflating Ecological Systems and Cycles

    ERIC Educational Resources Information Center

    Jordan, Rebecca; Gray, Steven; Demeter, Marylee; Lui, Lei; Hmelo-Silver, Cindy E.

    2009-01-01

    Teaching ecological concepts in schools is important in promoting natural science and environmental education for young learners. Developing educational programs is difficult, however, because of complicated ecological processes operating on multiple levels, the unlimited nature of potential system interactions (given the openness of systems), and…

  2. 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

  3. 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

  4. 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. PMID:26942529

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. The effect of altitude on cycling performance: a challenge to traditional concepts.

    PubMed

    Hahn, A G; Gore, C J

    2001-01-01

    Acute exposure to moderate altitude is likely to enhance cycling performance on flat terrain because the benefit of reduced aerodynamic drag outweighs the decrease in maximum aerobic power [maximal oxygen uptake (VO2max)]. In contrast, when the course is mountainous, cycling performance will be reduced at moderate altitude. Living and training at altitude, or living in an hypoxic environment (approximately 2500 m) but training near sea level, are popular practices among elite cyclists seeking enhanced performance at sea level. In an attempt to confirm or refute the efficacy of these practices, we reviewed studies conducted on highly-trained athletes and, where possible, on elite cyclists. To ensure relevance of the information to the conditions likely to be encountered by cyclists, we concentrated our literature survey on studies that have used 2- to 4-week exposures to moderate altitude (1500 to 3000 m). With acclimatisation there is strong evidence of decreased production or increased clearance of lactate in the muscle, moderate evidence of enhanced muscle buffering capacity (beta m) and tenuous evidence of improved mechanical efficiency (ME) of cycling. Our analysis of the relevant literature indicates that, in contrast to the existing paradigm, adaptation to natural or simulated moderate altitude does not stimulate red cell production sufficiently to increase red cell volume (RCV) and haemoglobin mass (Hb(mass)). Hypoxia does increase serum erthyropoietin levels but the next step in the erythropoietic cascade is not clearly established; there is only weak evidence of an increase in young red blood cells (reticulocytes). Moreover, the collective evidence from studies of highly-trained athletes indicates that adaptation to hypoxia is unlikely to enhance sea level VO2max. Such enhancement would be expected if RCV and Hb(mass) were elevated. The accumulated results of 5 different research groups that have used controlled study designs indicate that continuous

  11. 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.

  12. Mechanisms and concepts paving the way towards a complete transport cycle of plant vacuolar sorting receptors.

    PubMed

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

    2012-05-01

    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

  13. 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.

  14. Highly Variable Cycle Nozzle Concept: Validation of Flow and Noise Predictions

    NASA Technical Reports Server (NTRS)

    Halbig, Michael C.

    2011-01-01

    Results from experimental and numerical studies of highly Variable Cycle (HVC) exhaust model were presented. The model was designed and fabricated under a Supersonics NRA awarded to Rolls-Royce. The model had a lobed mixer for the core stream nozzle, and elliptic fan stream nozzle, and an ejector. Experiments included far-field acoustic array, phased array, and Particle Image Velocimetry (PIV) measurements. Numerical studies included flow simulations using the WIND-US code and far-field acoustic solutions using an acoustic analogy developed by Goldstein (2003) and Leib and Goldstein (2011). Far-field acoustic measurements showed increased noise levels over the round baseline nozzle when using non-static forward flight conditions. Phased array measurements showed noise sources near the ejector doors when tones were produced for small ejector door positions. Ejector door separation identified in the experiments was reproduced in the numerical flow simulations. Acoustic solutions were unable to match levels measured in the peak jet noise direction indicating additional development work is needed to predict noise from highly three-dimensional flows.

  15. 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

  16. Prospective randomized study of D-Trp6-LHRH versus buserelin in long desensitization protocols for medically assisted conception cycles.

    PubMed

    Gianaroli, L; Ferraretti, A P; Feliciani, E; Tabanelli, C; Magli, C; Fortini, D

    1994-02-01

    In a prospective, controlled, randomized study where two different agonists were used, we compared three different long desensitization protocols for induction of multiple follicular growth in medically assisted conception cycles. In protocol A, 30 patients were injected with buserelin twice a day for 15 days prior to ovarian stimulation until human chorionic gonadotrophin (HCG) administration. In protocol B, 30 patients were injected with a single dose of long acting Triptorelin (3.75 mg) 15 days before the ovarian stimulation onset. In protocol C, 30 patients were injected with the long acting Triptorelin 4 weeks before ovarian stimulation followed by daily administration of 0.1 mg of the same agonist until HCG injection. There was no difference in the ovarian response to exogenous gonadotrophin stimulation, except for the presence of premature luteinization in two patients in group B. A significantly higher number of mature oocytes was collected from patients with protocol A; however, the fertilization and cleavage rate demonstrated no significant difference among the three groups of patients. The ongoing pregnancy rate and the implantation rate per treatment cycle were very similar in the three study groups. When the convenience, cost and side-effects for the patient are being considered, protocol B should be selected as the first choice when the agonist is utilized for the purpose of inducing pituitary desensitization before and during ovarian stimulation.

  17. Design concepts and advanced telerobotics development for facilities in the back end of the nuclear fuel cycle

    SciTech Connect

    Feldman, M.J.

    1987-01-01

    In the Fuel Recycle Division at the Oak Ridge National Laboratory, a comprehensive remote systems development program has existed for the past seven years. The new remote technology under development is expected to significantly improve remote operations by extending the range of tasks accomplished by remote means and increasing the efficiency of remote work undertaken. Five areas of the development effort are primary contributors to the goal of higher operating efficiency for major facilities for the back end of the nuclear fuel cycle. These areas are the single-cell concept, the low-flow ventilation concept, television viewing, equipment-mounting racks, and force-reflecting manipulation. These somewhat innovative directions are products of a design process where the technical scenario to be accomplished, the remote equipment to accomplish the scenario, and the facility design to house the equipment, are considered in an iterative design process to optimize performance, maximize long-term costs effectiveness, and minimize initial capital outlay. 14 refs., 3 figs.

  18. 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

  19. 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.

  20. 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

  1. Biogeochemical Cycling

    NASA Technical Reports Server (NTRS)

    Bebout, Brad; Fonda, Mark (Technical Monitor)

    2002-01-01

    This lecture will introduce the concept of biogeochemical cycling. The roles of microbes in the cycling of nutrients, production and consumption of trace gases, and mineralization will be briefly introduced.

  2. HTGR-GT closed-cycle gas turbine. A plant concept with inherent cogeneration, power plus heat production, capability

    NASA Astrophysics Data System (ADS)

    McDonald, C. F.

    1980-04-01

    The high grade sensible heat rejection characteristic of the high temperature gas cooled reactor gas turbine plant is suited to cogeneration. Cogeneration broadly covers combined power and heat operation modes. Cogeneration in this nuclear closed cycle plant includes: (1) bottoming Rankine cycle, (2) hot water or process steam production, (3) desalination, and (4) urban and industrial district heating. The HTGR-CT plant thermodynamic cycles, design features, and potential applications for the cogeneration operation modes are discussed. The HTGR-CT plant, which potentially approaches 50 percent overall efficiency in a combined cycle mode, can significantly aid national energy goals, particularly resource conservation.

  3. 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.

  4. La problématique de la maîtrise de l'inventaire plutonium et actinides mineurs dans le cycle du combustible nucléaire

    NASA Astrophysics Data System (ADS)

    Mouney, Henri

    2002-10-01

    The mastering of the plutonium and minor actinides inventory in the French Nuclear Cycle is based on a progressive approach from the present status, dealing with the partial reprocessing of spent fuels and the recycling of Pu in the MOX assemblies loaded in the 20 licensed PWRs. This strategy keeps the door open long-term, for example, for the eventual multirecycling of excess Pu in dedicated new assemblies, such as APA or CORAIL in order to stabilise the Pu inventory in the fuel cycle or allow its utilization in new types of fast reactors. Presently, in the framework of 1991 law, scenario studies relying on present and/or innovative technologies are carried out in order to transmute both Pu and minor actinides, thus minimising the quantities to be for disposal. To cite this article: H. Mouney, C. R. Physique 3 (2002) 773-782.

  5. 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.

  6. 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.

  7. 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…

  8. Le cycle de l'eau et les activités au sein de l'espace rural. Enjeux globaux, solutions locales et régionales

    NASA Astrophysics Data System (ADS)

    Perrier, Alain; Tuzet, Andrée

    2005-02-01

    The analysis of the water cycle emphasizes the weight of surface evaporation compared to rain and the weight of water availability compared to evaporation. The ocean is a huge machine producing water vapour contrary to the continents, where evaporation is limited by plants that must shield themselves from drying and particularly by bare soils where the surface drying slows down the water losses. The availability of water for the biosphere depends on the difference between rain and evaporation. This difference, often called 'net supply', can be modified by anthropogenic actions on the vegetation; for example, the anthropogenic actions such as drying climate (reducing evapotranspiration) increases the net supply; on the opposite, the large development of more and more covering vegetation (arboreous system, bocages, savannah...) decreases the net supply (larger surface evapotranspiration all over the year). Moreover, the feedback between climate and continental interface can modify the rainfall pattern and the thermal equilibrium, leading ecosystems to extreme situations such as drying climate and desertification (ET lower and lower) or equilibrium situations corresponding to large development of vegetation (ET close to EP). The anthropogenic pressure and the human food requirements lead human beings to keep nearly the whole available water of the biosphere, particularly to practise irrigated agriculture. This practise is on average two times more efficient than the rainy agriculture (which is why it is attractive); moreover, its water efficiency decreases according to the environment and its aridity. Except for arboreous systems and agroforestry, agriculture is always a system that leads more or less towards aridity, but we have to bring it under control and to make it sustainable. A good management of the whole rain requires an efficient organization of the territory to optimise the water consumption in order to protect the environment and its biodiversity, to

  9. 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.

  10. 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.

  11. Plant d-excess: a new concept and tool for exploring plant-soil-atmospheric water cycling

    NASA Astrophysics Data System (ADS)

    Simonin, K.; Apodaca, R. L.; Link, P.; Oshun, J.; Rempe, D. M.; Dawson, T. E.; Dietrich, W. E.; Fung, I.

    2010-12-01

    Determining the contribution of the soil and biotic surfaces to water cycling on Earth has been best accomplished using H and O stable isotope information, including one key variable called the “d-excess”. The d-excess or the y-intercept of the Global Meteoric Water Line (GMWL) was first given explicit consideration by Dansgaard (1964) and further described by Craig and Gordon (1965) as representing the dominant kinetic isotope effect determined by the atmospheric humidity and temperature conditions that water vapor “sees” and interacts with over the ocean or land surface. Here we extend the use of the d-excess parameter and advocate its use as a tool for characterizing the water pools and flux pathways that contribute to local hydrologic processes over landscapes. To date, a major hurdle for using d-excess to understand the impact of terrestrial hydrologic processes on atmospheric water vapor has been our inability to characterize the stable isotope composition of atmospheric water vapor at very high resolution. In a forested northern California Coast Range watershed, we apply new optical laser based technologies for quantifying all of the isotopologues of water in vapor and show, for the first time, high-resolution characterization of the sources of water and their contribution to water vapor flux. Our findings highlight the strong influence of vegetation on atmospheric water vapor via the d-excess parameter. During the day, non-steady state isotope effects dominate resulting in d-excess values that exceed the estimated d-excess for the local meteoric water line (LMWL). At night vegetation has a strong effect on atmospheric water vapor via equilibrium processes that result in d-excess values for atmospheric water vapor that are significantly less than the LMWL. Our study highlights the critical importance of quantifying both H and O isotopes in water samples which shows how variation in d-excess depends on the partition between evaporation and

  12. Experiments on egg transfer in the cow and ewe: dependence of conception rate on the transfer procedure and stage of the oestrous cycle.

    PubMed

    Lawson, R A; Rowson, L E; Moor, R M; Tervit, H R

    1975-10-01

    The effects on embryo survival of procedures used in transferring eggs non-surgically were investigated in three experiments in ewes and heifers. In Exp. 1, two techniques for introducing eggs into the uterus through the cervix in heifers were compared; namely (i) deposition of the eggs high into the uterine horn or (ii) into the body of the uterus. Both methods were followed by inflation of the uterus with carbon dioxide. Out of a total of 34 heifers, only one became pregnant by the use of Method (i). Non-surgical egg tansfers early (Days 3 to 5) or later (Days 6 to 9) in the oestrous cycles of heifers were carried out in Exp. 2. Three transfer procedures were compared: (i) pipette transfer of an egg into the body of the uterus through the cervix (control), (ii) the control procedure performed under Fluothane anaesthesia, or (iii) followed by inflation of the uterus with carbon dioxide. Wide transfers carried out early in the cycle, pregnancies resulted in 1/10, 0/10 and 1/10 of the heifers in the control, carbon dioxide and Fluothane groups, respectively. With late transfers, 7/20, 1/10 and 8/20 heifers became pregnant in the respective treatment groups. This trend for pregnancy rate to be improved when late transfers were done in the control and Fluothane groups was significant only at the 10% level of probability when both groups were pooled. It was tentatively concluded, however, that non-surgical transfers of fertilized eggs to heifers may be best done during mid-cycle, after Day 6. Fluothane anaesthesia did not improve conception rate. Inflation of the uterus with carbon dioxide appeared to be deleterious when used at the mid-cycle stage in heifers. In Exp. 3, it was found that inflation of the ewe's uterus with carbon dioxide or nitrogen following the surgical thansfer of an egg did not affect the incidence of pregnancy. The introduction of 50 mul liquid Fluothane into the lumen of the uterus was embryotoxic.

  13. The Learning Cycle.

    ERIC Educational Resources Information Center

    Beisenherz, Paul C.; Dantonio, Marylou; Richardson, Lon

    2000-01-01

    The Learning Cycle contains three phases. In the exploration phase, students construct shared understanding of critical characteristics of a concept. The teacher introduces a concept in the concept introduction phase. The application phase introduces activities to extend the concept. Includes five concept activities. (SAH)

  14. Advanced radiator concepts

    NASA Technical Reports Server (NTRS)

    Diem-Kirsop, P. S.

    1985-01-01

    The liquid droplet radiator and the liquid belt radiator currently under study by the NASA LeRC are discussed. These advanced concepts offer benefits in reduced mass, compact stowage, and ease of deployment. Operation and components of the radiators are described, heat transfer characteristics are discussed, and critical technologies are identified. The impact of the radiators on large power systems is also assessed.

  15. A 1.26 μW Cytomimetic IC Emulating Complex Nonlinear Mammalian Cell Cycle Dynamics: Synthesis, Simulation and Proof-of-Concept Measured Results.

    PubMed

    Houssein, Alexandros; Papadimitriou, Konstantinos I; Drakakis, Emmanuel M

    2015-08-01

    Cytomimetic circuits represent a novel, ultra low-power, continuous-time, continuous-value class of circuits, capable of mapping on silicon cellular and molecular dynamics modelled by means of nonlinear ordinary differential equations (ODEs). Such monolithic circuits are in principle able to emulate on chip, single or multiple cell operations in a highly parallel fashion. Cytomimetic topologies can be synthesized by adopting the Nonlinear Bernoulli Cell Formalism (NBCF), a mathematical framework that exploits the striking similarities between the equations describing weakly-inverted Metal-Oxide Semiconductor (MOS) devices and coupled nonlinear ODEs, typically appearing in models of naturally encountered biochemical systems. The NBCF maps biological state variables onto strictly positive subthreshold MOS circuit currents. This paper presents the synthesis, the simulation and proof-of-concept chip results corresponding to the emulation of a complex cellular network mechanism, the skeleton model for the network of Cyclin-dependent Kinases (CdKs) driving the mammalian cell cycle. This five variable nonlinear biological model, when appropriate model parameter values are assigned, can exhibit multiple oscillatory behaviors, varying from simple periodic oscillations, to complex oscillations such as quasi-periodicity and chaos. The validity of our approach is verified by simulated results with realistic process parameters from the commercially available AMS 0.35 μm technology and by chip measurements. The fabricated chip occupies an area of 2.27 mm2 and consumes a power of 1.26 μW from a power supply of 3 V. The presented cytomimetic topology follows closely the behavior of its biological counterpart, exhibiting similar time-dependent solutions of the Cdk complexes, the transcription factors and the proteins. PMID:26316209

  16. Two further comments on Durkheim's Le Suicide.

    PubMed

    Andriessen, Karl

    2007-01-01

    It appears that the publications of Goldney and Schioldann (2000, 2001a,b, 2002) touched a chord, namely, the quality of the basic literature of contemporary suicidology and the usage of certain words and concepts. This paper adds two comments to this discussion. The first comment focuses on the usage of "altruistic," "egoistic," and "anomic" suicide. The second is a comment on the reception of Le Suicide.

  17. 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…

  18. 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.

  19. 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. PMID:22181097

  20. 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.

  1. 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

  2. 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,…

  3. Student Mini-Learning Exercise (SMiLE) Cards: Theory into Practice--Now!

    ERIC Educational Resources Information Center

    Tauber, Robert

    Based on the premise that educational psychology is often taught as theory with few opportunities for practical application, the Student Mini-Learning Exercise (SMiLE) Cards are presented to help students apply educational psychology concepts to field experiences. Components of these SMiLE Cards focus on: identification information; the concept…

  4. 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. PMID:25305651

  5. Analyse quantitative des faciès carbonatés et cycles T R de haute fréquence dans le Barrémien du Prébalkan central (Bulgarie)

    NASA Astrophysics Data System (ADS)

    Minkovska, Viara; Peybernès, Bernard; Cugny, Pierre; Nikolov, Todor

    2004-07-01

    Within the Emerici zone-Barremense zone biostratigraphic interval, the Barremian deposits of Central Fore-Balkan (Lovech-Veliko Tarnovo shelf) consist of a succession of several formations where alternate terrigenous argillaceous/sandy-dominated facies (Kormjansko Fm., Balgarene Fm.) and carbonate-dominated ('Urgonian') facies (Krushevo Fm., Emen Fm.). The qualitative and, particularly, quantitative facies analysis of the carbonate successions observed along 13 detailed cross-sections and in one drill hole show the stacking of about 40 fifth-order T-R cycles induced by numerous eustatic jerks contributing to the progressive settlement of this shelf. These high-frequency cycles of about 100 000 years must be regarded as valuable correlation tools for the subsurface hydrocarbon research. To cite this article: V. Minkovska et al., C. R. Geoscience 336 (2004).

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

    1975-01-01

    The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

  12. 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

  13. 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.

  14. Le couplage pulsation-convection.

    NASA Astrophysics Data System (ADS)

    Poyet, J.-P.

    Contents: Quelques problèmes Boussinesq bien definis. Les théories de couplage pulsation radiale-convection. Quelques pas dans le domaine du couplage des pulsations non radiales avec la convection. Conclusion.

  15. 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.

  16. 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

  17. Pattern of induced estrus and conception rate following Ovsynch and Ovsynch based gonadotropin-releasing hormone treatments initiated on day 6 of estrous cycle in repeat breeding crossbred cows

    PubMed Central

    Ahmed, N.; Kathiresan, D.; Ahmed, F. A.; Lalrintluanga, K.; Mayengbam, P.; Gali, J. M.

    2016-01-01

    Aim: The aim was to evaluate the estrus response, incidence of accessory corpus luteum formation and fertility following different hormonal protocols in repeat breeding crossbred cows. Materials and Methods: This study was carried out on 24 repeat breeding crossbred cows allotted into four groups. Cows of Group I was not given any treatment, Group II was treated with gonadotropin-releasing hormone (GnRH) injection on day 6 post-estrus, Group III was treated with Ovsynch protocol, and Group IV was treated with Ovsynch based GnRH treatment. Estrus responses such as duration, onset, percentage, and intensity of estrus were recorded during the study. The incidence of accessory corpus luteum was recorded per rectally on day 7 after first and additional GnRH of Ovsynch treatment. The conception rate for all groups was calculated by the absence of estrus and on day 45 after artificial insemination (AI) per rectum. Serum samples were collected at AI and day 12 post-AI in Group I and II. Serum samples were also collected at GnRH, Prostaglandin F2α (PGF2α), timed AI (TAI) and day 12 post-TAI in Group III and IV. Results: Ovsynch and Ovsynch based GnRH treatments are resulted in 100.00% induction of estrus after the PGF2α injection. Onset of induced estrus after the PGF2α injection for Group III and IV was recorded as 48.750±0.713 and 51.472±1.989 h, respectively, and it was not significant. There was no significant difference in duration of estrus among the groups. The incidence of intermediate estrus intensity was found to be highest. All the cows showed the incidence of formation of accessory corpus luteum subsequent to GnRH treatment on day 6 of the estrous cycle in Group II, III, and IV. The conception rate was 0.00%, 16.67%, 50.00%, and 50.00% in Group I, II, III, and IV, respectively. Conclusion: Ovsynch and Ovsynch based GnRH treatments initiated on day 6 of estrous cycle capable of responding with a higher percentage of ovulation and formation of accessory

  18. CONCEPT LEARNING AND CONCEPT TEACHING.

    ERIC Educational Resources Information Center

    GLASER, ROBERT

    REVIEWED ARE THE PSYCHOLOGICAL STUDIES OF CONCEPT LEARNING AS THEY RELATE TO CONCEPT TEACHING. AN ANALYSIS IS MADE OF THE NATURE OF CONCEPT LEARNING AS IT IS STUDIED IN THE PSYCHOLOGIST'S LABORATORY, INCLUDING THE NATURE OF CONCEPT TASKS AS THEY APPEAR IN SUBJECT MATTER LEARNING. THE PRIMARY KINDS OF CONCEPT LEARNING SITUATIONS, INCLUDING THE…

  19. Le LHC, un tunnel cosmique

    SciTech Connect

    2009-09-17

    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

  20. 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.

  1. LeChâtelier's Principle in the Sciences

    NASA Astrophysics Data System (ADS)

    Thomsen, Volker B. E.

    2000-02-01

    LeChâtelier's principle of chemical equilibrium is actually a very general statement about systems in equilibrium and their behavior when subjected to external force or stress. Although one almost never finds mention of his name or law in other sciences, analogous principles and concepts do exist. In this note we examine some of the similar forms taken by this chemical principle in the fields of physics, geology, biology, and economics. Lenz's law in physics is an example of electromagnetic equilibrium and the geological principle of isostatic uplift concerns mechanical equilibrium. Both are strictly consequences of conservation of energy. LeChâtelier's principle deals with thermodynamic equilibrium and involves both the first and second laws of thermodynamics. The concept of homeostasis in biology and the economic law of supply and demand are both equilibrium-like principles, but involve systems in the steady state. However, all these principles involve the stability of the system under consideration and the analogies presented may be useful in the teaching of LeChâtelier's principle.

  2. 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…

  3. 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

  4. Menstrual Cycle

    MedlinePlus

    ... Pregnancy This information in Spanish ( en español ) 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 ...

  5. 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…

  6. 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

  7. 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…

  8. 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…

  9. Le sevrage de l’allaitement

    PubMed Central

    Grueger, Barbara

    2013-01-01

    RÉSUMÉ L’allaitement exclusif assure une alimentation optimale aux nourrissons jusqu’à l’âge de six mois. Par la suite, les nourrissons ont besoin d’aliments complémentaires pour répondre à leurs besoins nutritionnels. C’est alors que le sevrage commence. Le sevrage désigne le processus graduel d’introduction d’aliments complémentaires au régime du nourrisson, tout en poursuivant l’allaitement. Il n’y a pas de moment universellement accepté ou scientifiquement démontré pour mettre un terme à l’allaitement. Le moment et le processus de sevrage doivent être adaptés par la mère et l’enfant. Le sevrage peut être soudain ou graduel, prendre plusieurs semaines ou plusieurs mois, être dirigé par l’enfant ou par la mère. Les médecins doivent orienter et soutenir les mères tout au long du processus de sevrage. Le présent document remplace le document de principes sur le sevrage qu’a publié la Société canadienne de pédiatrie en 2004.

  10. FES cycling.

    PubMed

    Newham, D J; Donaldson, N de N

    2007-01-01

    Spinal cord injury (SCI) leads to a partial or complete disruption of motor, sensory, and autonomic nerve pathways below the level of the lesion. In paraplegic patients, functional electrical stimulation (FES) was originally widely considered as a means to restore walking function but this was proved technically very difficult because of the numerous degrees of freedom involved in walking. FES cycling was developed for people with SCI and has the advantages that cycling can be maintained for reasonably long periods in trained muscles and the risk of falls is low. In the article, we review research findings relevant to the successful application of FES cycling including the effects on muscle size, strength and function, and the cardiovascular and bone changes. We also describe important practical considerations in FES cycling regarding the application of surface electrodes, training and setting up the stimulator limitations, implanted stimulators and FES cycling including FES cycling in groups and other FES exercises such as FES rowing.

  11. 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.

  12. 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

  13. 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)

  14. 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…

  15. 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.

  16. 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.

  17. Cycle Analysis

    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 andmore » 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.« less

  18. 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.

  19. Performance of LE-7 LOX pump inducer

    NASA Astrophysics Data System (ADS)

    Kamijo, Kenjiro; Yamada, Hitoshi; Hashimoto, Ryohei; Tsujimoto, Yoshinobu

    A liquid oxygen turbopump has been developed for the main engine (LE-7) of the H-II rocket. The LE-7 LOX pump requires an inducer with quite high suction performance and high head, because a low-speed pump is not used ahead of the main pump in the LE-7 engine. The inducer was designed using the customary method and its hydraulic and mechanical performances were investigated in tests of LE-7 LOX turbopumps. The original combination of an inducer and an inducer housing satisfied the required hydraulic performance criteria. However, this combination was found to result in supersynchronous shaft vibrations due to rotating cavitation which occurred in the inducer. This problem was almost completely solved by a simple modification of the inducer upstream housing. Furthermore, the rotating cavitation of the present inducer was investigated using a new theory of such cavitation developed by Tsujimoto, et al.

  20. 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)

  1. Synaptic plasticity and cell cycle activation in neurons are alternative effector pathways: the 'Dr. Jekyll and Mr. Hyde concept' of Alzheimer's disease or the yin and yang of neuroplasticity.

    PubMed

    Arendt, Thomas

    2003-10-01

    Mental actions are based on the dynamic organization of neuronal networks. In particular, phylogenetically young brain areas (e.g., cortical associative circuits) involved in the realization of higher brain functions are continuously re-adjusted to meet environmental demands. The mechanisms of synaptic plasticity, i.e., of structural stabilization and labilization underlying a life-long synaptic remodelling, are largely based on external morphoregulatory cues and internal signalling pathways that non-neuronal cells have phylogenetically acquired to sense their relationship to the local neighbourhood and to control after development is completed proliferation and differentiation in the process of tissue repair and regeneration. After having withdrawn from the cell cycle, differentiated neurons are, thus, able to use molecular mechanisms primarily developed to control proliferation alternatively to control synaptic plasticity. The existence of these alternative effector pathways within a neuron puts it at risk to erroneously convert signals derived from plastic synaptic changes into positional cues that will activate the cell cycle. This cell cycle activation potentially links synaptic plasticity to cell death. Preventing cell cycle activation by locking neurons in a differentiated but still highly plastic phenotype will, thus, be crucial to prevent neurodegeneration. PMID:14687983

  2. 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.

  3. Difficult Concepts

    NASA Astrophysics Data System (ADS)

    Fosbury, R.

    2005-12-01

    Beautiful colour images of the sky are both a blessing and a curse for the communication of astronomy to the public. While undoubtedly attractive, they can obscure the fact that discoveries are often made in astrophysics using techniques and measurements that are much more difficult to grasp and certainly less appealing to view. Should we try to explain such concepts as spectroscopy, polarimetry and interferometry, or is it a lost cause? The most effective approach to this problem may be to lead the audience to ask the question themselves: "But how do you know that?"

  4. 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.

  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. 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…

  7. 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 (5)…

  8. 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)

  9. 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.

  10. 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.

  11. 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

  12. [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.

  13. 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

  14. Low-temperature volumetric receiver concept

    NASA Astrophysics Data System (ADS)

    Drost, M. K.

    1988-09-01

    This document describes an alternative solar central receiver concept that offers the potential for a substantial reduction in the cost of electrical energy. The concept consists of a low temperature volumetric receiver which supplies 1100 F air to a Kalina cycle heat engine. Hot air can also be supplied to a packed bed of Dresser basalt where the hot air is used to heat the bed. The thermal energy stored in the bed can be extracted and supplied to the Kalina cycle during periods of low insolation. Previous investigations of the volumetric receiver concentrated on high temperature applications. The results showed that the volumetric concept could be very efficient, but the receiver was expensive and there were significant technical problems. Areas of technical uncertainty included fiber durability, the feasibility of inducing a preswirl and cost effective applications. The use of the volumetric receiver to produce low temperature will avoid the problems identified in the high temperature studies. The attractiveness of the low temperature concept is enhanced by the availability of the Kalina cycle. This heat engine was developed as a bottoming cycle for Brayton and Rankine cycle power plants. The key feature of the Kalina cycle is its ability to efficiently utilize the energy in a relatively low temperature heat source. The combination of the low temperature volumetric receiver and the Kalina cycle is particularly interesting.

  15. Low-temperature volumetric receiver concept

    SciTech Connect

    Drost, M.K.

    1988-09-01

    This document describes an alternative solar central receiver concept that offers the potential for a substantial reduction in the cost of electrical energy. The concept consists of a low temperature volumetric receiver which supplies 1100/degree/F air to a Kalina cycle heat engine. Hot air can also be supplied to a packed bed of Dresser basalt where the hot air is used to heat the bed. The thermal energy stored in the bed can be extracted and supplied to the Kalina cycle during periods of low insolation. Previous investigations of the volumetric receiver concentrated on high temperature applications. The results showed that the volumetric concept could be very efficient, but the receiver was expensive and there were significant technical problems. Areas of technical uncertainty included fiber durability, the feasibility of inducing a preswirl and cost effective applications. The use of the volumetric receiver to produce low temperature will avoid the problems identified in the high temperature studies. The attractiveness of the low temperature concept is enhanced by the availability of the Kalina cycle. This heat engine was developed as a bottoming cycle for Brayton and Rankine cycle power plants. The key feature of the Kalina cycle is its ability to efficiently utilize the energy in a relatively low temperature heat source. The combination of the low temperature volumetric receiver and the Kalina cycle is particularly interesting. 7 refs., 2 figs., 3 tabs.

  16. 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

  17. 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?”.

  18. 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

  19. 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…

  20. 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.

  1. 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

  2. 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

  3. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2001-04-01

    Les étoiles massives nouvellement nées secouent leur berceau; Première observation de la matière sombre; Le bruit cosmique X; L'âge de l'univers; Supernova record; Premiers pas en interférométrie;

  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. 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)

  7. 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 "vouloir,""pouvoir," and "venir,"…

  8. Le Francais Moderne: Part I, 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 Moderne: Part 1" focus on the development of vocabulary and mastery of grammatical structures. The formation of the passe compose with "avoir," object pronouns, the present tense of regular "-ir" verbs, and the irregular verbs…

  9. A Colorful Demonstration of Le Chbtelier's Principle.

    ERIC Educational Resources Information Center

    Last, Arthur M.; Slade, Peter W.

    1997-01-01

    Le Chbtelier's Principle states that, when a system at equilibrium is subjected to stress, the system will respond in such a way as to minimize the effect of the stress. Describes a lecture demonstration that illustrates shifts in the position of equilibrium caused by a variety of factors. The equilibrium mixture contains iron (III) and…

  10. A TACSAT SAR concept

    NASA Astrophysics Data System (ADS)

    Hall, C. D.; Baker, C. J.; Keyte, G. E.; Murphy, L. M.

    1993-02-01

    The payload concept covered is that of a low cost, high performance radar sensor capable of detecting and recognizing static objects within an imaged scene of the Earth's surface using the Synthetic Aperture Radar (SAR) technique. The overall system is integrated with a TACSAT platform in Low Earth Orbit (LEO) and, although only passing reference is made to this feature, the radar could also have a capability for the detection of Ground Moving Targets (GMTI). A parametric review of such a sensor in the light of the target and background features to be observed is provided. A design concept is included showing the possible hardware realization of a candidate system, as well as budgets for the mass, size, power, and pointing requirements of the instrument. Additional design features considered are the influence that short duration missions may have on hardware redundancy and the effect of short, low duty-cycle observation periods on solar array and battery sizing. The way towards a low cost R and D demonstrator system allowing a practical investigation of the key techniques and technologies is addressed.

  11. 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

  12. 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.

  13. Variable cycle engines for advanced supersonic transports

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.; Kozlowski, H.

    1975-01-01

    Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

  14. 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.

  15. 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;

  16. Your Menstrual Cycle

    MedlinePlus

    ... during your menstrual cycle What happens during your menstrual cycle The menstrual cycle includes not just your period, but the rise ... tool is based on a sample 28-day menstrual cycle, but every woman is different in how long ...

  17. Gravity in the Century of Light: The Gravitation Theory of Georges-Louis Le Sage

    NASA Astrophysics Data System (ADS)

    Evans, James

    2006-05-01

    Each generation of physicists, or natural philosophers, has sought to place universal gravitation in the context of its own worldview. Often this has entailed an effort to reduce gravitation to something more fundamental. But what is deemed fundamental has, of course, changed with time. Each generation attacked the problem of universal gravitation with the tools of its day and brought to bear the concepts of its own standard model. The most successful eighteenth-century attempt to provide a mechanical explanation of gravity was that of Georges-Louis Le Sage (1724-1803) of Geneva. Le Sage postulated a sea of ultramundane corpuscles, streaming in all directions and characterized by minute mass, great velocity, and complete inelasticity. Mostly these corpuscles just pass through gross bodies such as apples or planets, but a few are absorbed, leading to all the phenomena of attraction. In a voluminous correspondence with nearly all the savants of the day, Le Sage constantly reshaped his arguments for his system in order to appeal to metaphysicians, mechanicians and Newtonians of several varieties. Le Sage's theory is an especially interesting one, for several reasons. First, it serves as the prototype of a dynamical explanation of Newtonian gravity. Second, the theory came quite close to accomplishing its aim. Third, the theory had a long life and attracted comment by the leading physical thinkers of several successive generations, including Laplace, Kelvin, Maxwell and Feynman. Le Sage's theory therefore provides an excellent opportunity for the study of the evolution of attitudes toward physical explanation. The effects of national style in science and generational change take on a new clarity.

  18. 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?

  19. 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.

  20. 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

  1. 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

  2. A biogeochemical cycle for aluminium?

    PubMed

    Exley, Christopher

    2003-09-15

    The elaboration of biogeochemical cycles for elements which are known to be essential for life has enabled a broad appreciation of the homeostatic mechanisms which underlie element essentiality. In particular they can be used effectively to identify any part played by human activities in element cycling and to predict how such activities might impact upon the lithospheric and biospheric availability of an element in the future. The same criteria were the driving force behind the construction of a biogeochemical cycle for aluminium, a non-essential element which is a known ecotoxicant and a suspected health risk in humans. The purpose of this exercise was to examine the concept of a biogeochemical cycle for aluminium and not to review the biogeochemistry of this element. The cycle as presented is rudimentary and qualitative though, even in this nascent form, it is informative and predictive and, for these reasons alone, it is deserving of future quantification. A fully fledged biogeochemical cycle for aluminium should explain the biospheric abundance of this element and whether we should expect its (continued) active involvement in biochemical evolution.

  3. 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.

  4. 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...

  5. ALMA Cycle 0 Publication Statistics

    NASA Astrophysics Data System (ADS)

    Stoehr, F.; Grothkopf, U.; Meakins, S.; Bishop, M.; Uchida, A.; Testi, L.; Iono, D.; Tatematsu, K.; Wootten, A.

    2015-12-01

    The scientific impact of a facility is the most important measure of its success. Monitoring and analysing the scientific return can help to modify and optimise operations and adapt to the changing needs of scientific research. The methodology that we have developed to monitor the scientific productivity of the ALMA Observatory, as well as the first results, are described. We focus on the outcome of the first cycle (Cycle 0) of ALMA Early Science operations. Despite the fact that only two years have passed since the completion of Cycle 0 and operations have already changed substantially, this analysis confirms the effectiveness of the underlying concepts. We find that ALMA is fulfilling its promise as a transformational facility for the observation of the Universe in the submillimetre.

  6. 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.

  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. PMID:21537597

  8. Conceptions of Parents, Conceptions of Self, and Conceptions of God.

    ERIC Educational Resources Information Center

    Buri, John R.; Mueller, Rebecca A.

    Different theorists have suggested that an individual's view of God may be related to one's view of one's father, one's mother, or one's self. A study was conducted to examine the relationship of college students' conceptions of the wrathfulness-kindliness of God to their conceptions of their father's and mother's permissiveness, authoritarianism,…

  9. Completion of nonreducible Le Fort fractures by Le Fort I osteotomy: sometimes an inevitable choice to avoid postoperative malocclusion.

    PubMed

    Scolozzi, Paolo; Imholz, Benoît

    2015-01-01

    The aim of this study was to prospectively evaluate the use of a simultaneous Le Fort I osteotomy for completion of nonreducible Le Fort fractures. We analyzed the clinical and radiological data of 44 patients with Le Fort fractures, 9 of whom presented with a nonreducible type. Seven patients with an incomplete Le Fort I fracture had a contralateral Le Fort I osteotomy, and 2 patients with an incomplete Le Fort III fracture had a true bilateral Le Fort I-type osteotomy. We recorded age and sex, mechanism of injury, level of Le Fort fracture, concomitant mandibular fractures, concomitant maxillomandibular fixation (MMF) and its duration, surgical approach, status of healing, and complications. Follow-ups were at 1 week and 1, 3, 6, and 12 months.All patients recovered their normal pretrauma occlusion without the need for postoperative elastic guidance, except for 1 patient who required light class III traction elastics for 3 weeks to achieve the correct occlusion. None of the patients presented with intraoperative or postoperative complications.The present study has demonstrated that completion of nonreducible Le Fort fractures by Le Fort I osteotomy results in a high rate of success.

  10. 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.

  11. 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…

  12. Research-Concept Evaluation

    NASA Technical Reports Server (NTRS)

    White, M. J.; Kolb, W.

    1985-01-01

    Concepts ranked according to potential benefit/cost ratios. ARINC Researh Concept Evaluation Methodology (ARCEM) program provides powerful tool for organization and planning of research activities indicating which concepts provide greatest benefit for investment and determines number of concepts implemented to justify expenditures for development of generic technologies.

  13. René Le Fort 1869-1951.

    PubMed

    Noffze, Michael J; Tubbs, R Shane

    2011-04-01

    Over a century ago, The French surgeon René Le Fort described the anatomical basis for fractures of the mid-face. His nomenclature is still used today using the eponym "Le Fort fractures." Although Le Fort's name is well known in association with the fractures that he described, little is known of his life. Therefore, the present article will discuss the background of this important individual in craniofacial trauma.

  14. 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

  15. Development of long operating cycle simplified BWR

    SciTech Connect

    Heki, H.; Nakamaru, M.; Maruya, T.; Hiraiwa, K.; Arai, K.; Narabayash, T.; Aritomi, M.

    2002-07-01

    This paper describes an innovative plant concept for long operating cycle simplified BWR (LSBWR) In this plant concept, 1) Long operating cycle ( 3 to 15 years), 2) Simplified systems and building, 3) Factory fabrication in module are discussed. Designing long operating core is based on medium enriched U-235 with burnable poison. Simplified systems and building are realized by using natural circulation with bottom located core, internal CRD and PCV with passive system and an integrated reactor and turbine building. This LSBWR concept will have make high degree of safety by IVR (In Vessel Retention) capability, large water inventory above the core region and no PCV vent to the environment due to PCCS (Passive Containment Cooling System) and internal vent tank. Integrated building concept could realize highly modular arrangement in hull structure (ship frame structure), ease of seismic isolation capability and high applicability of standardization and factory fabrication. (authors)

  16. Industrial ecology: concepts and approaches.

    PubMed

    Jelinski, L W; Graedel, T E; Laudise, R A; McCall, D W; Patel, C K

    1992-02-01

    Industrial ecology is a new approach to the industrial design of products and processes and the implementation of sustainable manufacturing strategies. It is a concept in which an industrial system is viewed not in isolation from its surrounding systems but in concert with them. Industrial ecology seeks to optimize the total materials cycle from virgin material to finished material, to component, to product, to waste product, and to ultimate disposal. To better characterize the topic, the National Academy of Sciences convened a colloquium from which were derived a number of salient contributions. This paper sets the stage for the contributions that follow and discusses how each fits into the framework of industrial ecology.

  17. Trois inconnues qui bouleversent le Big Bang

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    2002-10-01

    Deux coups de tonnerre gigantesques dans le ciel de la cosmologie ont très récemment chamboulé notre vision de l'univers. Avec l'apparition d'une mystérieuse énergie sombre et la confirmation de la platitude de l'Univers, toutes les théories sur son évolution sont à revoir. Aujourd'hui l'Univers n'a plus de visage et tout est à reconstruire. Retour sur une histoire à rebondissements.

  18. 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.

  19. 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.

  20. Modelisation numerique et validation experimentale d'un systeme de protection contre le givre par elements piezoelectriques

    NASA Astrophysics Data System (ADS)

    Harvey, Derek

    Le degivrage au moyen d'actuateurs piezoelectriques est considere comme une avenue prometteuse pour le developpement de systemes a faible consommation d'energie applicables aux helicopteres legers. Ce type de systeme excite des frequences de resonances d'une structure pour produire des deformations suffisantes pour rompre l'adherence de la glace. Par contre, la conception de tel systeme demeure generalement mal comprise. Ce projet de maitrise etudie l'utilisation de methodes numeriques pour assister la conception des systemes de protection contre le givre a base d'elements piezoelectriques. La methodologie retenue pour ce projet a ete de modeliser differentes structures simples et de simuler l'excitation harmonique des frequences de resonance au moyen d'actuateurs piezoelectriques. Le calcul des frequences de resonances ainsi que la simulation de leur excitation a ensuite ete validee a l'aide de montages experimentaux. La procedure a ete realisee pour une poutre en porte-a-faux et pour une plaque plane a l'aide du logiciel de calcul par elements finis, Abaqus. De plus, le modele de la plaque plane a ete utilise afin de realiser une etude parametrique portant sur le positionnement des actuateurs, l'effet de la rigidite ainsi que de l'epaisseur de la plaque. Finalement, la plaque plane a ete degivree en chambre climatique. Des cas de degivrage ont ete simules numeriquement afin d'etudier la possibilite d'utiliser un critere base sur la deformation pour predire le succes du systeme. La validation experimentale a confirme la capacite du logiciel a calculer precisement a la fois les frequences et les modes de resonance d'une structure et a simuler leur excitation par des actuateurs piezoelectriques. L'etude revele que la definition de l'amortissement dans le modele numerique est essentiel pour l'obtention de resultats precis. Les resultats de l'etude parametrique ont demontre l'importance de minimiser l'epaisseur et la rigidite afin de reduire la valeur des frequences

  1. 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)

  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. The Empathy Cycle: Refinement of a Nuclear Concept.

    ERIC Educational Resources Information Center

    Barrett-Lennard, G.T.

    1981-01-01

    Delineates a sequence of distinct stages involved in empathic interaction. There is room for considerable slippage between the inner resonation, communication, and reception levels, and measures based on data from different phases would at best be moderately associated. Principal existing (state) scales are located in reference to the model.…

  4. Le spasme du sanglot chez les nourrissons

    PubMed Central

    Goldman, Ran D.

    2015-01-01

    Résumé Question Des enfants qui fréquentent ma clinique ont des épisodes semblables à des convulsions pendant lesquels ils pleurent et retiennent leur souffle au point de faire survenir une cyanose et de perdre conscience. Les résultats à l’examen ou aux investigations sont normaux et les pédiatres consultés ne font pas d’autres investigations. Les spasmes du sanglot sont-ils communs et quels genres d’investigations faut-il faire? Réponse Le spasme du sanglot est un trouble non épileptique paroxysmal bénin qui se produit chez les enfants en santé de six à 48 mois. Les épisodes commencent par une provocation, comme un bouleversement émotionnel ou une blessure mineure, et peuvent progresser en une retenue de la respiration, une cyanose et une syncope. Les épisodes sont extrêmement effrayants à regarder mais ont des conséquences bénignes. Une fois le diagnostic clinique posé, on recommande de faire passer un électrocardiogramme et d’exclure la possibilité d’une anémie, mais aucune autre investigation ou demande de consultation n’est nécessaire.

  5. Characterization of biological types of cattle (Cycle VII): influence of postpartum interval and estrous cycle length on fertility.

    PubMed

    Cushman, R A; Allan, M F; Thallman, R M; Cundiff, L V

    2007-09-01

    Genetic improvement in reproductive efficiency through selection is difficult because many reproductive traits are binomial and have low heritabilities. Before genetic markers can be generated for fertility in cows, greater characterization of reproductive phenotypes is needed to understand the components of the trait. The current study tested the hypotheses that: 1) breeds vary in postpartum interval to estrus (PPIE) and estrous cycle length, 2) a longer estrous cycle immediately before breeding increased pregnancy rates, and 3) a greater number of cycles before breeding increased conception rates. The postpartum interval to estrus, estrous cycle length, and number of cycles before breeding were examined in F1 cows (n = 519) obtained from mating Hereford, Angus, and MARC III cows to Hereford, Angus, Simmental, Limousin, Charolais, Gelbvieh, and Red Angus sires. Cows were classified as having 0, 1, 2, or 3 observed estrous cycles before breeding. All traits analyzed were adjusted to constant BCS. Sire breed of the cow influenced length of the PPIE and number of cycles before the start of breeding (P <0.001). Simmental-sired cows had the shortest PPIE and greatest number of cycles before breeding, whereas Limousin-sired cows had the longest PPIE and least number of cycles before breeding. Cows with a greater number of cycles before breeding did not have greater conception rates than cows that had not exhibited standing estrus before breeding (P = 0.87). In cows that cycled before breeding, the length of the estrous cycle immediately before breeding was influenced by dam breed and BCS (P <0.01). Cows out of Hereford dams had shorter estrous cycles than cows out of MARC III or Angus dams, and estrous cycle length increased as BCS increased. Conception rate decreased as length of the estrous cycle immediately before breeding increased (P = 0.05, -2.2% per d of cycle length). Therefore, previously anestrous cows were just as likely to conceive as cows that had cycled

  6. Characterization of biological types of cattle (Cycle VII): influence of postpartum interval and estrous cycle length on fertility.

    PubMed

    Cushman, R A; Allan, M F; Thallman, R M; Cundiff, L V

    2007-09-01

    Genetic improvement in reproductive efficiency through selection is difficult because many reproductive traits are binomial and have low heritabilities. Before genetic markers can be generated for fertility in cows, greater characterization of reproductive phenotypes is needed to understand the components of the trait. The current study tested the hypotheses that: 1) breeds vary in postpartum interval to estrus (PPIE) and estrous cycle length, 2) a longer estrous cycle immediately before breeding increased pregnancy rates, and 3) a greater number of cycles before breeding increased conception rates. The postpartum interval to estrus, estrous cycle length, and number of cycles before breeding were examined in F1 cows (n = 519) obtained from mating Hereford, Angus, and MARC III cows to Hereford, Angus, Simmental, Limousin, Charolais, Gelbvieh, and Red Angus sires. Cows were classified as having 0, 1, 2, or 3 observed estrous cycles before breeding. All traits analyzed were adjusted to constant BCS. Sire breed of the cow influenced length of the PPIE and number of cycles before the start of breeding (P <0.001). Simmental-sired cows had the shortest PPIE and greatest number of cycles before breeding, whereas Limousin-sired cows had the longest PPIE and least number of cycles before breeding. Cows with a greater number of cycles before breeding did not have greater conception rates than cows that had not exhibited standing estrus before breeding (P = 0.87). In cows that cycled before breeding, the length of the estrous cycle immediately before breeding was influenced by dam breed and BCS (P <0.01). Cows out of Hereford dams had shorter estrous cycles than cows out of MARC III or Angus dams, and estrous cycle length increased as BCS increased. Conception rate decreased as length of the estrous cycle immediately before breeding increased (P = 0.05, -2.2% per d of cycle length). Therefore, previously anestrous cows were just as likely to conceive as cows that had cycled

  7. 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)

  8. Transposed critical temperature Rankine thermodynamic cycle

    SciTech Connect

    Pope, W.L.; Doyle, P.A.

    1980-04-01

    The transposed critical temperature (TPCT) is shown to be an extremely important thermodynamic property in the selection of the working fluid and turbine states for optimized geothermal power plants operating on a closed organic (binary) Rankine cycle. When the optimum working fluid composition and process states are determined for given source and sink conditions (7 parameter optimization), turbine inlet states are found to be consistently adjacent to the low pressure side of the working fluids' TPCT line on pressure-enthalpy coordinates. Although the TPCT concepts herein may find numerous future applications in high temperature, advanced cycles for fossil or nuclear fired steam power plants and in supercritical organic Rankine heat recovery bottoming cycles for Diesel engines, this discussion is limited to moderate temperature (150 to 250/sup 0/C) closed simple organic Rankine cycle geothermal power plants. Conceptual design calculations pertinent to the first geothermal binary cycle Demonstration Plant are included.

  9. 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).

  10. 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)

  11. Race concepts in medicine.

    PubMed

    Hardimon, Michael O

    2013-02-01

    Confusions about the place of race in medicine result in part from a failure to recognize the plurality of race concepts. Recognition that the ordinary concept of race is not identical to the racialist concept of race makes it possible to ask whether there might be a legitimate place for the deployment of concepts of race in medical contexts. Two technical race concepts are considered. The concept of social race is the concept of a social group that is taken to be a racialist race. It is apt for use in examining and addressing the medical effects of discrimination. The populationist concept of race represents race as a kind of biological population. It makes it possible to frame the question whether biological race is a factor in disease susceptibility and drug responsiveness. It is apt for use in determining whether biological race is a medically significant category.

  12. 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.

  13. Advanced propulsion concepts

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    1991-01-01

    A variety of Advanced Propulsion Concepts (APC) is discussed. The focus is on those concepts that are sufficiently near-term that they could be developed for the Space Exploration Initiative. High-power (multi-megawatt) electric propulsion, solar sails, tethers, and extraterrestrial resource utilization concepts are discussed. A summary of these concepts and some general conclusions on their technology development needs are presented.

  14. Anhedonia: A Concept Analysis

    PubMed Central

    Ho, Nancy; Sommers, Marilyn

    2013-01-01

    Anhedonia presents itself in a myriad of disease processes. To further develop our understanding of anhedonia and effective ways to manage it, the concept requires clear boundaries. This paper critically examined the current scientific literature and conducted a concept analysis of anhedonia to provide a more accurate and lucid understanding the concept. As part of the concept analysis, this paper also provides model, borderline, related, and contrary examples of anhedonia. PMID:23706888

  15. 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.

  16. Model Organisms for Studying the Cell Cycle.

    PubMed

    Tang, Zhaohua

    2016-01-01

    Regulation of the cell-division cycle is fundamental for the growth, development, and reproduction of all species of life. In the past several decades, a conserved theme of cell cycle regulation has emerged from research in diverse model organisms. A comparison of distinct features of several diverse model organisms commonly used in cell cycle studies highlights their suitability for various experimental approaches, and recaptures their contributions to our current understanding of the eukaryotic cell cycle. A historic perspective presents a recollection of the breakthrough upon unfolding the universal principles of cell cycle control by scientists working with diverse model organisms, thereby appreciating the discovery pathways in this field. A comprehensive understanding is necessary to address current challenging questions about cell cycle control. Advances in genomics, proteomics, quantitative methodologies, and approaches of systems biology are redefining the traditional concept of what constitutes a model organism and have established a new era for development of novel, and refinement of the established model organisms. Researchers working in the field are no longer separated by their favorite model organisms; they have become more integrated into a larger community for gaining greater insights into how a cell divides and cycles. The new technologies provide a broad evolutionary spectrum of the cell-division cycle and allow informative comparisons among different species at a level that has never been possible, exerting unimaginable impact on our comprehensive understanding of cell cycle regulation.

  17. Production of IVF transgene-expressing bovine embryos using a novel strategy based on cell cycle inhibitors.

    PubMed

    Bevacqua, R J; Pereyra-Bonnet, F; Olivera, R; Hiriart, M I; Sipowicz, P; Fernandez-Martín, R; Radrizzani, M; Salamone, D F

    2012-07-01

    The objective was to evaluate the effects of cell cycle inhibitors (6-dimethylaminopurine [DMAP], and dehydroleukodine [DhL]) on transgene expression efficiency and on mosaic expression patterns of IVF bovine zygotes cytoplasmically injected with oolema vesicles coincubated with transgene. The DNA damage induced by the transgene or cell cycle inhibitors was measured by detection of phosphorylated histone H2AX foci presence (marker of DNA double-stranded breaks). Cloning of egfp blastomeres was included to determine continuity of expression after additional rounds of cellular division. The pCX-EGFP [enhanced green fluorescent protein gene (EGFP) under the chimeric cytomegalovirus IE-chicken-β-actin enhancer promoter control] gene plasmid (50 ng/μL) was injected alone (linear or circular exogenous DNA, leDNA and ceDNA, respectively) or associated with ooplasmic vesicles (leDNA-v or ceDNA-v). The effects of 2 mm DMAP or 1 μm DhL for 6 h (from 15 to 21 h post IVF) was evaluated for groups injected with vesicles. The DMAP increased (P < 0.05) egfp homogenous expression relative to transgene alone (21%, 18%, and 11% for leDNA-v + DMAP, leDNA-v, and leDNA, respectively) and also increased (P < 0.05) the phosphorylated histone H2AX foci area. Expression of egfp was higher (P < 0.05) for linear than for circular pCX-EGFP, and egfp blastocyst rates were higher (P < 0.05) for groups injected with linear transgene coincubated with vesicles than for linear transgene alone (95%, 77%, 84%, and 52% for leDNA-v + DMAP, leDNA-v + DhL, leDNA-v, and leDNA, respectively). Moreover, DMAP tended to improve egfp blastocysts rates for both circular and linear transgenes. Based on fluorescent in situ hybridization (FISH) analysis, there was evidence of integration in egfp embryos. Finally, clones derived from leDNA-v + DMAP had the highest egfp expression rates (96%, 65%, and 65% for leDNA-v + DMAP, leDNA-v, and leDNA, respectively). Transgenesis by cytoplasmic injection of le

  18. 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…

  19. 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.

  20. 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…

  1. Applications of Concept Mapping

    ERIC Educational Resources Information Center

    De Simone, Christina

    2007-01-01

    This article reviews three major uses of the concept-mapping strategies for postsecondary learning: the external representation of concept maps as an external scratch pad to represent major ideas and their organization, the mental construction of concept maps when students are seeking a time-efficient tool, and the electronic construction and…

  2. 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

  3. 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.

  4. Analyse de L'ancrage des Vortex Intergrains pour le Yttrium BARYUM(2) CUIVRE(3) OXYGENE(7) Polycristallin

    NASA Astrophysics Data System (ADS)

    Fournier, Patrick

    Le Modele de l'Etat Critique Generalise (MECG) est utilise pour decrire les proprietes magnetiques et de transport du YBa_2Cu_3O _7 polycristallin. Ce modele empirique permet de relier la densite de courant critique a la densite de lignes de flux penetrant dans la region intergrain. Deux techniques de mesures sont utilisees pour caracteriser nos materiaux. La premiere consiste a mesurer le champ au centre d'un cylindre creux en fonction du champ magnetique applique pour des temperatures comprises entre 20 et 85K. En variant l'epaisseur de la paroi du cylindre creux, il est possible de suivre l'evolution des cycles d'hysteresis et de determiner des champs caracteristiques qui varient en fonction de cette dimension. En utilisant un lissage des resultats experimentaux, nous determinons J _{co}, H_ {o} et n, les parametres du MECG. La forme des cylindres, avec une longueur comparable au diametre externe, entrai ne la presence d'un champ demagnetisant qui peut etre inclus dans le modele theorique. Ceci nous permet d'evaluer la fraction du volume ecrante, f _{g}, ainsi que le facteur demagnetisant N. Nous trouvons que J_{ co}, H_{o} et f_{g} dependent de la temperature, tandis que n et N (pour une epaisseur de paroi fixe) n'en dependent pas. La deuxieme technique consiste a mesurer le courant critique de lames minces en fonction du champ applique pour differentes temperatures. Nous utilisons un montage que nous avons developpe permettant d'effectuer ces mesures en contact direct avec le liquide refrigerant, i.e. dans l'azote liquide. Nous varions la temperature du liquide en variant la pression du gaz au-dessus du bain d'azote. Cette methode nous permet de balayer des temperatures entre 65K et la temperature critique du materiau ({~ }92K). Nous effectuons le lissage des courbes de courant critique en fonction du champ applique encore a l'aide du MECG, pour a nouveau obtenir ses parametres. Pour trois echantillons avec des traitements thermiques differents, les parametres

  5. The Use of Le by L1 Chinese Speakers and the Acquisition of Le by L2 Chinese Learners

    ERIC Educational Resources Information Center

    Bredeche, Chi Chen

    2011-01-01

    The perfective marker V-"le" is claimed to be one of the most problematic items in the acquisition of L2 Chinese, perhaps because no unified and comprehensive treatment of it exists in the literature. Although much has been written on this topic, the semantic and pragmatic functions of V-"le" have remained elusive. While linguists and grammarians…

  6. 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.

  7. 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.

  8. 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)

  9. 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…

  10. Consulting with Parents: Applying Family Systems Concepts and Techniques.

    ERIC Educational Resources Information Center

    Mullis, Fran; Edwards, Dana

    2001-01-01

    This article describes family systems concepts and techniques that school counselors, as consultants, can use to better understand the family system. The concepts are life cycle transitions and extrafamilial influences, extended family influences, boundaries, parental hierarchy and power, and triangulation. (Contains 39 references.) (GCP)

  11. The FOT tool kit concept

    NASA Technical Reports Server (NTRS)

    Fatig, Michael

    1993-01-01

    Flight operations and the preparation for it has become increasingly complex as mission complexities increase. Further, the mission model dictates that a significant increase in flight operations activities is upon us. Finally, there is a need for process improvement and economy in the operations arena. It is therefore time that we recognize flight operations as a complex process requiring a defined, structured, and life cycle approach vitally linked to space segment, ground segment, and science operations processes. With this recognition, an FOT Tool Kit consisting of six major components designed to provide tools to guide flight operations activities throughout the mission life cycle was developed. The major components of the FOT Tool Kit and the concepts behind the flight operations life cycle process as developed at NASA's GSFC for GSFC-based missions are addressed. The Tool Kit is therefore intended to increase productivity, quality, cost, and schedule performance of the flight operations tasks through the use of documented, structured methodologies; knowledge of past lessons learned and upcoming new technology; and through reuse and sharing of key products and special application programs made possible through the development of standardized key products and special program directories.

  12. 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.

  13. 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.

  14. Solar Cycle 25: Another Moderate Cycle?

    NASA Astrophysics Data System (ADS)

    Cameron, R. H.; Jiang, J.; Schüssler, M.

    2016-06-01

    Surface flux transport simulations for the descending phase of Cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipole moment around 2020 (2.5 ± 1.1 G) is comparable to that observed at the end of Cycle 23 (about 2 G). The empirical correlation between the dipole moment during solar minimum and the strength of the subsequent cycle thus suggests that Cycle 25 will be of moderate amplitude, not much higher than that of the current cycle. However, the intrinsic uncertainty of such predictions resulting from the random scatter of the source properties is considerable and fundamentally limits the reliability with which such predictions can be made before activity minimum is reached.

  15. Fast Track'' nuclear thermal propulsion concept

    SciTech Connect

    Johnson, R.A.; Zweig, H.R. ); Cooper, M.H.; Wett, J. Jr. )

    1993-01-10

    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).

  16. 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,…

  17. 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.

  18. 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.

  19. 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. PMID:17109998

  20. 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...

  1. Reproductive cycles of buffalo.

    PubMed

    Perera, B M A O

    2011-04-01

    The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live on poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17β are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving

  2. Reproductive cycles of buffalo.

    PubMed

    Perera, B M A O

    2011-04-01

    The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live on poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17β are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving

  3. Reconciliation--A Rhetorical Concept/ion

    ERIC Educational Resources Information Center

    Doxtader, Erik

    2003-01-01

    What is reconciliation? A source of historical puzzlement and contemporary controversy over how to make history, this question asks after those words which constitute a beginning (again), that moment in which endless cycles of conflict give way to the hope for "unity in difference." Concerned with the dynamics of its operation, the present essay…

  4. Integrated urban water cycle management: the UrbanCycle model.

    PubMed

    Hardy, M J; Kuczera, G; Coombes, P J

    2005-01-01

    Integrated urban water cycle management presents a new framework in which solutions to the provision of urban water services can be sought. It enables new and innovative solutions currently constrained by the existing urban water paradigm to be implemented. This paper introduces the UrbanCycle model. The model is being developed in response to the growing and changing needs of the water management sector and in light of the need for tools to evaluate integrated watercycle management approaches. The key concepts underpinning the UrbanCycle model are the adoption of continuous simulation, hierarchical network modelling, and the careful management of computational complexity. The paper reports on the integration of modelling capabilities across the allotment, and subdivision scales, enabling the interactions between these scales to be explored. A case study illustrates the impacts of various mitigation measures possible under an integrated water management framework. The temporal distribution of runoff into ephemeral streams from a residential allotment in Western Sydney is evaluated and linked to the geomorphic and ecological regimes in receiving waters.

  5. 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

  6. 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.

  7. 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)

  8. Impact de la varicocèle sur le volume testiculaire et les paramètres spermatiques

    PubMed Central

    Benazzouz, Mohamed Hicham; Essatara, Younes; El Sayegh, Hachem; Iken, Ali; Benslimane, Lounis; Nouini, Yassine

    2014-01-01

    Introduction La varicocèle est une pathologie masculine fréquente dont l'incidence est encore plus importante dans dans la population des hommes infertiles. Si ses mécanismes sont à ce jour incomplètement expliqués il semble acquis que la varicocèle peut être associée a une dysfonction testiculaire avec diminution du volume testiculaire et de la concentration en spermatozoïde de l’éjaculat. Méthodes Dans un premier temps nous exposons les résultats d'une étude rétrospective sur 5 ans (de Mars 2009 à Mars 2014), réalisée au service d'urologie A de l'hôpital Ibn Sina de Rabat et ayant comme objectif d’évaluer l'impact de la varicocèle palpable sur le volume testiculaire et les paramètres spermatiques. Tous les patients inclus dans notre étude avaient une varicocèle palpable. Dans un deuxième temps, et à travers une revue de la littérature nous discutons l'impact du traitement de la varicocèle sur la fertilité. Résultats 39 patients ont été inclus dans notre étude. L’âge moyen était de 29,71 ans et la varicocèle siégeait dans 89,74% des cas du coté gauche. Une atrophie testiculaire homolatérale à la varicocèle était retrouvée dans 7% des cas alors que des anomalies du spermogramme se voyaient dans 69,23% des cas. Conclusion L'impact de la varicocèle sur l'altération des paramètres spermatiques a été clairement établi bien que sa physio pathogénie ne soit pas bien élucidée. Le traitement chirurgical de la varicocèle semble indiqué chez les hommes infertiles présentant une varicocèle clinique et une altération significative du sperme. PMID:25918574

  9. Enquête entomologique dans le foyer historique de trypanosomose humaine africaine de Bendjé (Gabon)

    PubMed Central

    Kohagne Tongué, L.; Gounoue Kamkuimo, R.; Mengue M’eyi, P.; Kaba, D.; Louis, F.J.; Mimpfoundi, R.

    2011-01-01

    La situation de la maladie du sommeil est très peu connue au Gabon. De nombreux foyers historiques n’ont pas été prospectés depuis plus de 15 ans. Le foyer historique de Bendjé fournit régulièrement quelques cas, dépistés passivement, qui concernent le plus souvent des pêcheurs dont il est a priori difficile de déterminer le lieu probable de contamination du fait de leur grande mobilité au cours de leurs activités. La présence des hommes infectés dans ce foyer historique pourrait favoriser son réveil s’il existe un contact étroit entre les différents éléments potentiellement présents du cycle épidémiologique (homme, vecteur, trypanosome). Afin de vérifier l’existence éventuelle d’un risque trypanosomien dans ce foyer, nous y avons mené une enquête entomologique. Des pièges ont été posés dans des biotopes fréquentés par l’homme et laissés en place pendant quatre jours. Trois espèces de glossines (Glossina palpalis palpalis, G. pallicera newsteadi et G. caliginea) ont été capturées et deux espèces de trypanosomes (Trypanosoma vivax et T. brucei s.l.) identifiées par PCR. Ces résultats suggèrent l’existence d’un cycle de transmission animal. Le contact entre les hommes et les glossines est particulièrement étroit dans tous les types de site prospectés, à l’exception de la mangrove. PMID:22091460

  10. 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.

  11. Mapping commuter cycling risk in urban areas.

    PubMed

    Yiannakoulias, Nikolaos; Bennet, Scott A; Scott, Darren M

    2012-03-01

    Cycling is becoming an increasingly important transportation option for commuters. Cycling offers exercise opportunities and reduces the burden of motor vehicle travel on society. Mapping the risk of collision between cyclists and motor vehicles in urban areas is important to understanding safe cyclist route opportunities, making informed transportation planning decisions, and exploring patterns of injury epidemiology. To date, many geographic analyses and representations of cyclist risk have not taken the concept of exposure into account. Instead, risk is either expressed as a rate per capita, or as a count of events. Using data associated with the City of Hamilton, Canada, we illustrate a method for mapping commuter cyclist collision risk per distance travelled. This measure can be used to more realistically represent the underlying geography of cycling risk, and provide more geographically and empirically meaningful information to those interested in understanding how cycling safety varies over space. PMID:22269497

  12. Mapping commuter cycling risk in urban areas.

    PubMed

    Yiannakoulias, Nikolaos; Bennet, Scott A; Scott, Darren M

    2012-03-01

    Cycling is becoming an increasingly important transportation option for commuters. Cycling offers exercise opportunities and reduces the burden of motor vehicle travel on society. Mapping the risk of collision between cyclists and motor vehicles in urban areas is important to understanding safe cyclist route opportunities, making informed transportation planning decisions, and exploring patterns of injury epidemiology. To date, many geographic analyses and representations of cyclist risk have not taken the concept of exposure into account. Instead, risk is either expressed as a rate per capita, or as a count of events. Using data associated with the City of Hamilton, Canada, we illustrate a method for mapping commuter cyclist collision risk per distance travelled. This measure can be used to more realistically represent the underlying geography of cycling risk, and provide more geographically and empirically meaningful information to those interested in understanding how cycling safety varies over space.

  13. 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).

  14. Statistical cyclicity of the supercontinent cycle

    NASA Astrophysics Data System (ADS)

    Rolf, T.; Coltice, N.; Tackley, P. J.

    2014-04-01

    Supercontinents like Pangea impose a first-order control on Earth's evolution as they modulate global heat loss, sea level, climate, and biodiversity. In a traditional view, supercontinents form and break up in a regular, perhaps periodic, manner in a cycle lasting several 100 Myr as reflected in the assembly times of Earth's major continental aggregations: Columbia, Rodinia, and Pangea. However, modern views of the supercontinent cycle propose a more irregular evolution on the basis of an improved understanding of the Precambrian geologic record. Here we use fully dynamic spherical mantle convection models featuring plate-like behavior and continental drift to investigate supercontinent formation and breakup. We further dismiss the concept of regularity but suggest a statistical cyclicity in which the supercontinent cycle may have a characteristic period imposed by mantle and lithosphere properties, but this is hidden in immense fluctuations between different cycles that arise from the chaotic nature of mantle flow.

  15. Industrial ecology: concepts and approaches.

    PubMed Central

    Jelinski, L W; Graedel, T E; Laudise, R A; McCall, D W; Patel, C K

    1992-01-01

    Industrial ecology is a new approach to the industrial design of products and processes and the implementation of sustainable manufacturing strategies. It is a concept in which an industrial system is viewed not in isolation from its surrounding systems but in concert with them. Industrial ecology seeks to optimize the total materials cycle from virgin material to finished material, to component, to product, to waste product, and to ultimate disposal. To better characterize the topic, the National Academy of Sciences convened a colloquium from which were derived a number of salient contributions. This paper sets the stage for the contributions that follow and discusses how each fits into the framework of industrial ecology. PMID:11607253

  16. 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.

  17. 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.

  18. Cycling To Awareness.

    ERIC Educational Resources Information Center

    Kozak, Stan

    1999-01-01

    Encourages environmental and outdoor educators to promote bicycling. In the community and the curriculum, cycling connects environmental issues, health and fitness, law and citizenship, appropriate technology, and the joy of being outdoors. Describes the Ontario Cycling Association's cycling strategy and its four components: school cycling…

  19. HIV Life Cycle

    MedlinePlus

    HIV Overview The HIV Life Cycle (Last updated 9/8/2016; 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) ...

  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

    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.

  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; 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.

  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

    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.

  3. The genus Trichocnemis LeConte, 1851 (Coleoptera, Cerambycidae, Prioninae)

    PubMed Central

    Swift, Ian; Santos-Silva, Antonio; Nearns, Eugenio H.

    2010-01-01

    Abstract The history of the genus Trichocnemis LeConte, 1851 (Coleoptera, Cerambycidae, Prioninae) is discussed. Its taxonomic status in relation to the genera Ergates Audinet-Serville, 1832 and Callergates Lameere, 1904 is clarified. The synonymy of Macrotoma californica White, 1853, Macrotoma spiculigera White, 1853, and Trichocnemis spiculatus LeConte, 1851 is confirmed. A key to all three genera and their species is provided. PMID:21594014

  4. VentureStar(tm) Payload Processing Concept

    NASA Technical Reports Server (NTRS)

    Sharp, Susan

    1998-01-01

    The philosophy and the operations concept of the VentureStar(tm) payload processing system is presented. The goal of VentureStar(tm) operations is to provide low cost access to space. This is to be achieved through the design of the vehicle, and operability of the ground system. Specifically, this is to be accomplished through rapid turnaround cycles, increased launch rate, high system reliability and availability and reduced required operations personnel. This is presented in viewgraph format.

  5. General aviation turbine engine /GATE/ concepts

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    The paper deals with only a portion of the work done by Williams Research Corporation for NASA. It provides a look at possible new-generation powerplants that offer the potential for remarkable airplane performance gains with attendant safety, utility, productivity and life cycle cost benefits. Attention is given to a turboprop engine concept and applications. A turbofan engine having core components in common with the turboprop is also discussed and an airplane application shown. Some of the more important findings are presented.

  6. Transmaxillary Sinus Approach for Le Fort II Osteotomy.

    PubMed

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

    2016-02-01

    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.

  7. Three-dimensional Nasolabial Morphologic Alterations Following Le Fort I

    PubMed Central

    DeSesa, Christopher R.; Metzler, Philip; Sawh-Martinez, Rajendra

    2016-01-01

    Background: Le Fort I osteotomy imparts significant changes to the nasolabial region. Past studies have relied on 2-dimensional data and have not delineated differences among various Le Fort I subtypes. The purpose of this study is to 3-dimensionally analyze Le Fort I–induced nasal and lip changes comparing advancement alone versus widening alone [surgically assisted maxillary expansion (SAME)] versus advancement and widening. We hypothesize that the combination of maxillary advancement with widening will result in the most profound changes. Methods: A retrospective cohort study was performed. Included Le Fort I patients were grouped as: (1) nonsegmental straight advancement, (2) widening without advancement, and (3) segmental advancement and widening. Pre- and postoperative 3-dimensional photogrammetry (Canfield) were analyzed. Anthropometric landmarks were placed and measured by 2 independent observers. Statistics involved both paired and unpaired t tests (significance = P < 0.05). Results: One hundred eight photogrammetric data sets were analyzed, including 46 single-piece, 26 SAME, and 36 segmental. Significant postoperative nasal changes were observed within each intragroup analysis. The most dramatic changes were seen after segmental Le Fort I with advancement and widening, which included alar base width, alar width, nostril width, and soft triangle angle, all P < 0.05. Conclusions: Le Fort I osteotomy results in significant alteration of the nasolabial morphology. This is the first study to 3-dimensionally analyze nasal changes that occur comparing maxillary advancement alone versus widening alone (SAME) versus advancement with widening. These objective data permit improved patient counseling and surgical planning. PMID:27622116

  8. 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

  9. 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.

  10. Three-dimensional Nasolabial Morphologic Alterations Following Le Fort I

    PubMed Central

    DeSesa, Christopher R.; Metzler, Philip; Sawh-Martinez, Rajendra

    2016-01-01

    Background: Le Fort I osteotomy imparts significant changes to the nasolabial region. Past studies have relied on 2-dimensional data and have not delineated differences among various Le Fort I subtypes. The purpose of this study is to 3-dimensionally analyze Le Fort I–induced nasal and lip changes comparing advancement alone versus widening alone [surgically assisted maxillary expansion (SAME)] versus advancement and widening. We hypothesize that the combination of maxillary advancement with widening will result in the most profound changes. Methods: A retrospective cohort study was performed. Included Le Fort I patients were grouped as: (1) nonsegmental straight advancement, (2) widening without advancement, and (3) segmental advancement and widening. Pre- and postoperative 3-dimensional photogrammetry (Canfield) were analyzed. Anthropometric landmarks were placed and measured by 2 independent observers. Statistics involved both paired and unpaired t tests (significance = P < 0.05). Results: One hundred eight photogrammetric data sets were analyzed, including 46 single-piece, 26 SAME, and 36 segmental. Significant postoperative nasal changes were observed within each intragroup analysis. The most dramatic changes were seen after segmental Le Fort I with advancement and widening, which included alar base width, alar width, nostril width, and soft triangle angle, all P < 0.05. Conclusions: Le Fort I osteotomy results in significant alteration of the nasolabial morphology. This is the first study to 3-dimensionally analyze nasal changes that occur comparing maxillary advancement alone versus widening alone (SAME) versus advancement with widening. These objective data permit improved patient counseling and surgical planning.

  11. Le Conte's sparrows breeding in Conservation Reserve Program fields: precipitation and patterns of population change

    USGS Publications Warehouse

    Igl, Lawrence D.; Johnson, Douglas H.

    1999-01-01

    The climate of the North American Great Plains is highly dynamic, with great year-to-year variability in precipitation and periodic, often extreme, wet and dry cycles (Bragg 1995). Drought is a major force of ecological disturbance on the Great Plains and has played a key role in directing the evolution of the grassland biota of this region (Knopf and Samson 1997). Although grassland birds may differ in their responses to enviromenental variations (Rotenberry and Wiens 1991), climatic variability and concomitant unpredictability of resources strongly influence populations of grassland birds across space and time (Wiens 1974, 1986; Cody 1985). Not surprisingly, breeding bird populations on the Great Plains are highly dynamic, exhibiting considerable annual variation in composition, abundance, and distribution (Johnson and Grier 1988, George et al. 1992, Zimmerman 1992, Igl and Johnson 1997). Recently, interest in grassland birds has increased with the recognition that many species are declining both continentally (Droege and Sauer 1994) and globally (Goriup 1988). Identification of the specific factors associated with grassland bird declines in North America, however, remains largely enigmatic (Herkert 1997), and it is complicated by the considerable annual fluctuations in grassland bird distribution and abundance (Igl and Johnson 1997). Although there is evidence that land-use changes on the breeding grounds may have contributed to grassland bird declines (e.g., Igl and Johnson 1997), there also is an indication that long-term drought conditions may have influenced recent population changes of some breeding birds on the Great Plains (Droege and Sauer 1989, Peterjohn and Sauer 1993, Bethke and Nudds 1995, Igl and Johnson 1997). Le Conte's Sparrow (Ammodramus leconteii) is a secretive grassland bird that breeds in central and southern Canada and the northcentral United States (Murray 1969). It winters primarily in the southern United States (Peterson 1980, 1990

  12. Children's Conceptions of Jesus

    ERIC Educational Resources Information Center

    Aylward, Karen; Freathy, Rob

    2008-01-01

    This paper presents findings from a recent study investigating young children's (aged 10-11) conceptions of Jesus in England. The overall picture revealed by the study is that whilst there was a general assent amongst pupils in our sample towards an ethical and humanistic conception of the historical Jesus, there was less of a consensus about…

  13. The Concept of Information.

    ERIC Educational Resources Information Center

    Capurro, Rafael; Hjorland, Birger

    2003-01-01

    Reviews the status of the concept of information in information science, with reference to interdisciplinary trends. Highlights include defining scientific terms; studies and sources of the word information; the concept of information in the natural sciences, and in the humanities and social sciences; librarianship; information retrieval; and the…

  14. Badminton--Teaching Concepts.

    ERIC Educational Resources Information Center

    Gibbs, Marilyn J.

    1988-01-01

    Teaching four basic badminton concepts along with the usual basic skill shots allows players to develop game strategy awareness as well as mechanical skills. These four basic concepts are: (1) ready position, (2) flight trajectory, (3) early shuttle contact, and (4) camouflage. (IAH)

  15. 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…

  16. Children's Concepts of Death.

    ERIC Educational Resources Information Center

    Kane, Barbara

    1979-01-01

    A total of 122 middle-class White boys and girls aged 3 through 12 years were interviewed to determine the nature and the development of their concepts of death and the impact of experience on those concepts. (Author/BH)

  17. 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 circumstances of the…

  18. 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…

  19. The Concept of Density

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    2004-01-01

    Students are aware of the theoretical or abstract concept of density, but fail to understand its practical implication in that the thickness concentrated in a solid object is what constitutes density. A study of the density concept reveals its very practical and qualitative nature, and the students must look beyond theoretical equations to…

  20. Threshold Concepts in Economics

    ERIC Educational Resources Information Center

    Shanahan, Martin

    2016-01-01

    Purpose: The purpose of this paper is to examine threshold concepts in the context of teaching and learning first-year university economics. It outlines some of the arguments for using threshold concepts and provides examples using opportunity cost as an exemplar in economics. Design/ Methodology/Approach: The paper provides an overview of the…

  1. Ultrastructural localization of glycodelin oligosaccharides Le-x and Le-y in human seminal vesicles by immunogold staining

    PubMed Central

    Piludu, M; Cossu, M; De Lisa, A; Piras, M; Lantini, M S

    2007-01-01

    Histo-blood group antigens Le-x and Le-y are oligosaccharidic terminals that characterize many glycoproteins in the human tissues. In seminal plasma, they are expressed as part of the so-called glycodelin S, which is suggested to regulate sperm capacitation/decapacitation. It has recently been demonstrated that the core protein of glycodelin S is secreted by seminal vesicles. Here we show that epithelial cells of human seminal vesicles also release the Le-x and Le-y antigens. The presence of these substances in secretory material was revealed by means of an immunogold staining method in normal surgical samples. The results suggest that glycodelin S is secreted by seminal vesicles in its finished glycosylated form. Moreover, antigen reactivity was also revealed associated with plasma membranes. PMID:17331183

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. Feminism: a concept analysis.

    PubMed

    Allan, H T

    1993-10-01

    The purpose of this paper is to analyse the concept of feminism in order to clarify a sociological concept for its use in nursing theory and practice. This analysis is carried out using the Walker & Avant (1988) model. It includes: a literature review, an overview of the uses of the concept drawn from the literature, the defining attributes and the justification of their choice, the cases to demonstrate the concept, and the concept criteria. The concept was chosen out of an interest in developing a feminist nursing theory and desire to enhance nursing practice. The literature search proved most fruitful in the sociological literature. The nursing sources were fewer and concerned with practice rather than articulating any feminist nursing theory. Many of these sources were sociologists and nurses. The concept of feminism was defined as the concern with gender equality and the promotion of equal rights for men and woman, the expression of these concerns through theory or action, and the valuing of individuals for their contributions to society rather than their biological or sexual characteristics or roles. Although the concept of feminism was defined and analysed within the model suggested by Walker & Avant, the author found that the concept became oversimplified, losing much of the richness of the literature. The author felt that, for any development of theory or practice, this analysis would have to be expanded. It is argued that their model is too restrictive as it is based on positivist philosophy which seeks to establish divisions where, in fact, there is a blurring of meaning.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. 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. PMID:21423359

  10. 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)

  11. The status of the HOPE concept study

    NASA Astrophysics Data System (ADS)

    Kouchiyama, Jirou; Eguchi, Akihiro

    1993-03-01

    National Space Development Agency of Japan (NASDA) has been studying an unmanned winged vehicle called the H-2 Orbiting Plane (HOPE). The HOPE will be launched by H-2 launch vehicle or H-2 derivative launch vehicle, and injected into low orbit. After a few days stay in space for access to the space station, HOPE will de-orbit and go back to a named landing site automatically. The concept of the 10-ton class vehicle launched by H-2 launch vehicle was prepared in 1988. However, its payload capability is not enough for the practical use of the space station expected at the beginning of the 21st century. Therefore, the concept of 20-ton class vehicle launched by the Solid Rocket Booster (SRB)-added H-2 launch vehicle without the second stage (Liquid Engine-5A (LE-5A) engine) was studied in 1989. This vehicle will be injected into low orbit by its own propulsion system. Its payload capability was estimated at 3 tons. In the study from 1990 to 1991, it was revealed that the reduction of the HOPE weight is the most important problem. At present, the shapes of the main wing, the orbital injection systems (reusable engine or expendable one), and the materials of the main structure (carbon/polyimide) are being studied to reduce the weight.

  12. Low cycle fatigue

    NASA Technical Reports Server (NTRS)

    Solomon, H. D. (Editor); Kaisand, L. R. (Editor); Halford, G. R. (Editor); Leis, B. N. (Editor)

    1988-01-01

    The papers contained in this volume focus on various aspects of low cycle fatigue, including cyclic deformation, crack propagation, high-temperature low cycle fatigue, microstructural defects, multiaxial and variable amplitude loading, and life prediction. Papers are presented on the low cycle fatigue of some aluminum alloys, prediction of crack growth under creep-fatigue loading conditions, high-temperature low cycle fatigue behavior and lifetime prediction of a nickel-base ODS alloy, and an integrated approach to creep-fatigue life prediction. Other topics discussed include thermal fatigue testing of coated monocrystalline superalloys, low cycle fatigue of Al-Mg-Si alloys, and the effect of superimposed stresses at high frequency on low cycle fatigue.

  13. What a Concept! Using Concept Mapping on Handheld Computers

    ERIC Educational Resources Information Center

    Royer, Regina; Royer, Jeff

    2004-01-01

    When designed properly, concept mapping activities can engage students in meaningful learning. In the process of creating concept maps, students relate new information to more general concepts already held, develop fuller understandings of those general concepts, and recognize new relationships between concepts. Students engage in these activities…

  14. Concepts in Change

    NASA Astrophysics Data System (ADS)

    Rusanen, Anna-Mari; Pöyhönen, Samuli

    2013-06-01

    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 unwarranted. Hence, the strong analogy between scientific theory change and individual learning should be approached with caution. In addition, we argue that (2) research in psychology and cognitive science provides a promising theoretical basis for developing explanatory mechanistic models of conceptual change. Moreover, we argue that (3) arguments against deeper integration between the fields of psychology and conceptual change are not convincing, and that recent theoretical developments in the cognitive sciences might prove indispensable in filling in the details in mechanisms of conceptual change.

  15. 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.

  16. 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...

  17. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Wind tunnel model of Manned Orbiting Research Laboratory concept on sting. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  18. Space Station - early concept

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Display model of space station concept--Manned Orbiting Research Laboratory in Saturn S-IVB Orbit configuration. Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995).

  19. 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. PMID:24238005

  20. Overcoming: A Concept Analysis

    PubMed Central

    Brush, Barbara L.; Kirk, Keri; Gultekin, Laura; Baiardi, Janet M.

    2011-01-01

    This article provides an operational definition of overcoming as a first step in the systematic analysis of the concept. Using the method described by Walker and Avant (2005), the authors identify the attributes and characteristics of overcoming and its theoretical and practical application to nursing. Sample cases from clinical research illustrate the concept further. Further nursing research needs to test the theoretical relationships between overcoming and outcome variables. PMID:21806626

  1. Solar activity secular cycles

    NASA Astrophysics Data System (ADS)

    Kramynin, A. P.; Mordvinov, A. V.

    2013-12-01

    Long-term variations in solar activity secular cycles have been studied using a method for the expansion of reconstructed sunspot number series Sn( t) for 11400 years in terms of natural orthogonal functions. It has been established that three expansion components describe more than 98% of all Sn( t) variations. In this case, the contribution of the first expansion component is about 92%. The averaged form of the 88year secular cycle has been determined based on the form of the first expansion coordinate function. The quasi-periodicities modulating the secular cycle have been revealed based on the time function conjugate to the first function. The quasi-periodicities modulating the secular cycle coincide with those observed in the Sn( t) series spectrum. A change in the secular cycle form and the time variations in this form are described by the second and third expansion components, the contributions of which are about 4 and 2%, respectively. The variations in the steepness of the secular cycle branches are more pronounced in the 200-year cycle, and the secular cycle amplitude varies more evidently in the 2300-year cycle.

  2. 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

  3. [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.

  4. 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.

  5. Additional orthognathic surgery following Le Fort III and monobloc advancement.

    PubMed

    Nout, E; Koudstaal, M J; Wolvius, E B; Van der Wal, K G H

    2011-07-01

    Severe midface hypoplasia in patients with various craniofacial anomalies can be corrected with Le Fort III or monobloc advancement. Often additional corrective orthognathic surgery is indicated to achieve Class I occlusion and a normal inter-jaw relationship. This study evaluated the incidence of, and the surgical indications for, secondary orthognathic surgery following Le Fort III/monobloc advancement. The total study group consisted of 41 patients: 36 patients with Le Fort III advancement and 5 patients with monobloc advancement. Seven patients underwent additional orthognathic surgery. Of the resulting 18 non-operated patients older than 18 years at the end of follow-up, Class I occlusion was observed in 11 patients. In the remaining patients malocclusions were dentally compensated with orthodontic treatment. None of the patients was scheduled for additional orthognathic surgery due to the absence of functional complaints and/or resistance to additional surgery. Le Fort III and monobloc advancement aim to correct skeletal deformities on the level of zygoma, orbits, nasal area and forehead, but Class I occlusion is frequently not achieved. Additional orthognathic surgery is often indicated in patients undergoing Le Fort III or monobloc advancement. Naso-endoscopic analysis of the upper airway and the outcomes of sleep studies may influence the orthognathic treatment plan.

  6. Trigeminocardiac reflex and haemodynamic changes during Le Fort I osteotomy.

    PubMed

    Kiani, M T; Tajik, G; Ajami, M; Fazli, H; Kharazifard, M J; Mesgarzadeh, A

    2016-05-01

    The Le Fort I osteotomy is performed under general anaesthesia and specific haemodynamic conditions, i.e. hypotensive general anaesthesia. This study assessed the incidence of the trigeminocardiac reflex (TCR) during the different stages of the Le Fort I osteotomy. Forty-seven patients requiring a Le Fort I osteotomy were included. General anaesthesia was induced. In terms of haemodynamic changes, each patient's oxygen saturation (SpO2), mean arterial pressure (MAP), heart rate (HR), and electrocardiogram (ECG) were monitored by SADAAT Monitoring System and recorded during the different stages of osteotomy: before the induction of anaesthesia, before osteotomy cuts, after finishing the right pterygoid plate osteotomy, after finishing the left pterygoid plate osteotomy, and after performing down-fracture of the maxilla. No significant alteration in haemodynamic values was seen at the different stages of Le Fort I osteotomy. One patient showed arrhythmia with non-sinus junction rhythm after sinus bradycardia and two premature atrial contractions in the down-fracture stage, which led to the abrupt cessation of the procedure by the surgeon. This study showed no significant alterations in haemodynamic values during the different stages of Le Fort I osteotomy. Halting the procedure momentarily was sufficient to allow spontaneous normalization of the HR, blood pressure, and dysrhythmia.

  7. 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. PMID:27068874

  8. 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.

  9. 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.

  10. Measuring Cycling Effort.

    ERIC Educational Resources Information Center

    Jahnke, Thomas; Hamson, Mike

    1999-01-01

    Investigates the basic mechanics of cycling with a simple reckoning of how much effort is needed from the cyclist. The work done by the cyclist is quantified when the ride is on the flat and also when pedaling uphill. Proves that by making use of the available gears on a mountain bike, cycling uphill can be accomplished without pain. (Author/ASK)

  11. 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.

  12. 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…

  13. 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)

  14. 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…

  15. 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.

  16. 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,…

  17. Reusable thermal cycling clamp

    NASA Technical Reports Server (NTRS)

    Debnam, W. J., Jr.; Fripp, A. L.; Crouch, R. K. (Inventor)

    1985-01-01

    A reusable metal clamp for retaining a fused quartz ampoule during temperature cycling in the range of 20 deg C to 1000 deg C is described. A compressible graphite foil having a high radial coefficient of thermal expansion is interposed between the fused quartz ampoule and metal clamp to maintain a snug fit between these components at all temperature levels in the cycle.

  18. 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

  19. Le fort I maxillary advancement using distraction osteogenesis.

    PubMed

    Combs, Patrick D; Harshbarger, Raymond J

    2014-11-01

    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.

  20. 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

  1. Le lipome para testiculaire: à propos d'un cas rare

    PubMed Central

    Lasri, Abdelouahed; Lamchahab, Hamza; Lahyani, Mounir; Karmouni, Tarik; Elkhader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Ibn Attya

    2015-01-01

    Les tumeurs para testiculaires sont des tumeurs rares et complexes qui ont une symptomatologie insidieuse et pauvre. Les formes bénignes représentent 70%. Le lipome para testiculaire étant le type le plus fréquent. L'examen clinique est peu spécifique. L'examen échographique est la pierre angulaire pour assoir le diagnostic. Le traitement chirurgical s'impose en cas de tumeur symptomatique, l'histologie étant habituellement typique permet la confirmation diagnostique. Le pronostic est bon malgré d’éventuelles récidives. PMID:26175802

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Le lymphome primitif de la vessie: un cas clinique

    PubMed Central

    Statoua, Mouad; Mokrim, Maha; El Ghanmi, Jihad; Karmouni, Tariq; El Khadir, Khalid; Koutani, Abdellatif; Attya, Ahmed Iben; Errihani, Hassan

    2014-01-01

    Les tumeurs de vessie constituent les tumeurs les plus fréquentes de l'appareil uro-génital chez l'homme, le type histologique est dominé par le carcinome urothéliale, la localisation primitive du lymphome malin est extrêmement rare et constitue souvent une surprise diagnostique quand elle est retrouvée. Nous rapportons à travers cette observation le cas d'un patient pris en charge au sein de notre formation qui a bénéficié, suite a un bilan d'hématurie objectivant une formation bourgeonnante intra vésicale a l’échographie abdominale, d'une résection transurétrale de la vessie d'un polype géant dont les résultats anapathologies sont revenus en faveur d'un lymphome primitif de la vessie, le patient a bénéficié d'une chimiothérapie adjuvante a base de RCHOP, les suites étaient simples et une surveillance cystoscopique et scannographique n'a pas objectivé de récidive avec un recul de 18 mois. Le lymphome primitif de la vessie est une entité rare, sa chimio sensibilité fait de ce type de tumeur une maladie curable, le diagnostic est histologique et vu la rareté de l'affection aucun consensus n'est standardisé. PMID:25419286

  9. 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

  10. 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.

  11. 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.

  12. 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. PMID:27024999

  13. 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.

  14. The Chlamydomonas cell cycle.

    PubMed

    Cross, Frederick R; Umen, James G

    2015-05-01

    The position of Chlamydomonas within the eukaryotic phylogeny makes it a unique model in at least two important ways: as a representative of the critically important, early-diverging lineage leading to plants; and as a microbe retaining important features of the last eukaryotic common ancestor (LECA) that has been lost in the highly studied yeast lineages. Its cell biology has been studied for many decades and it has well-developed experimental genetic tools, both classical (Mendelian) and molecular. Unlike land plants, it is a haploid with very few gene duplicates, making it ideal for loss-of-function genetic studies. The Chlamydomonas cell cycle has a striking temporal and functional separation between cell growth and rapid cell division, probably connected to the interplay between diurnal cycles that drive photosynthetic cell growth and the cell division cycle; it also exhibits a highly choreographed interaction between the cell cycle and its centriole-basal body-flagellar cycle. Here, we review the current status of studies of the Chlamydomonas cell cycle. We begin with an overview of cell-cycle control in the well-studied yeast and animal systems, which has yielded a canonical, well-supported model. We discuss briefly what is known about similarities and differences in plant cell-cycle control, compared with this model. We next review the cytology and cell biology of the multiple-fission cell cycle of Chlamydomonas. Lastly, we review recent genetic approaches and insights into Chlamydomonas cell-cycle regulation that have been enabled by a new generation of genomics-based tools.

  15. Cycles, Cycles Everywhere - Corals, Coccoliths, and Climate

    NASA Astrophysics Data System (ADS)

    Ridgwell, A.

    2004-05-01

    Critical to our understanding of both past and future climate change is the biogeochemcial cycle of carbon on Earth. This is popularly recognized in the context of the creation and destruction of solid organic matter such as vegetation and fossil fuels, which has a clear and intuitive relationship to the amount of carbon dioxide in the atmosphere. Less widely recognized is the cycling which involves solid inorganic carbon as carbonate minerals - the most abundant form of carbon present at or near the surface of the Earth, and one with a distinctly counter-intuitive relationship with atmospheric CO2. For instance, changes in the rate of production of coral skeletons may have played a role in Holocene climate change, but with increased carbonate carbon removal driving atmospheric CO2 higher and not lower. The carbonate skeletons produced by some species of plankton in the open ocean are also critical to the climate system. The sinking of these skeletal parts is currently suspected to be important in helping to transport organic matter to depth and thus temporarily isolating this carbon from the atmosphere. The deposition of plankton-derived carbonate to the sediments of the deep-sea also helps regulate atmospheric CO2 but on thousand year time-scales, and will play a key role in the eventual removal of fossil fuel carbon from the atmosphere. However, there is a growing awareness that carbonate production by plankton may be severely diminished in the future. Maybe the cycle of carbonate on Earth could be re-set to how it operated over two hundred million years ago. Here I review some of the current areas of interest in global carbonate cycling, particularly its relationship to climate change and to fundamental moments in the evolution of life.

  16. [Concepts of anthropological medicine].

    PubMed

    Petzold, E R; Petzold, U

    2001-01-01

    Medical anthropology is the teaching of the ill human being, of being ill; anthropological medicine is the realization of this teaching in practice. This concept was first developed and assessed in the "Gestaltkreis" and in the Pathosophy (44), in Medicine in Motion (39), and in the Bipersonality (10). The four most important concepts are represented, which have their origin and aim in anthropological medicine: anthropological medicine, Balint-work, family-oriented medicine, and salutogenesis. These concepts are exemplified in the Aachen psychosomatic liaison model, the Aachen Balint cooperation model, and the Aachen model of psychosomatic care. We wish to portray the meaning of these resources for the medicine of the future, since they have proven to be effective, cost-saving, and easy to be handled. In the latter part of our presentation, we will document this point with a pilot study conducted in Israel and in our own clinic in Aachen. PMID:11603206

  17. Communication, concepts and grounding.

    PubMed

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  18. Basic concepts of depression

    PubMed Central

    Paykel, Eugene S.

    2008-01-01

    This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1930s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed. PMID:18979941

  19. Basic concepts of depression.

    PubMed

    Paykel, Eugene S

    2008-01-01

    This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century, as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1980s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed.

  20. 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.

  1. Fuel cycle centers revisited: Consolidation of fuel cycle activities in a few countries

    SciTech Connect

    Kratzer, M.B.

    1996-07-01

    Despite varied expressions, the general impression remains that the international fuel cycle center concept, whatever its merits, is visionary. It also is quite possibly unattainable in light of strong national pressures toward independence and self-sufficiency in all things nuclear. Is the fuel cycle center an idea that has come and gone? Is it an idea whose time has not yet come? Or is it, as this paper suggests, an idea that has already arrived on the scene, attracting little attention or even acknowledgement of its presence? The difficult in answering this questions arises, in part, from the fact that despite its long and obvious appeal, there has been very little systematic analysis of the concept itself. Such obvious questions as how many and where fuel cycle centers should be located; what characteristics should the hot country or countries possess; and what are the institutional forms or features that endow the concept with enhanced proliferation protection have rarely been seriously and systematically addressed. The title of this paper focuses on limiting the geographic spread of fuel cycle facilities, and some may suggest that doing so does not necessarily call for any type of international or multinational arrangements applicable to those that exist. It is a premise of this paper, however, that a restriction on the number of countries possessing sensitive fuel cycle facilities necessarily involves some degree of multinationalization. This is not only because in every instance a nonproliferation pledge and international or multinational safeguards, or both, will be applied to the facility, but also because a restriction on the number of countries possessing these facilities implies that those in existence will serve a multinational market. This feature in itself is an important form of international auspices. Thus, the two concepts--limitation and multinationalization--if not necessarily one and the same, are at least de facto corollaries.

  2. 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.

  3. Mars Rover Concept Development

    NASA Astrophysics Data System (ADS)

    McTamaney, Louis S.; Harmon, Scott Y.

    1989-03-01

    FMC conducted a carefully structured study effort designed to develop an extensive set of mobility and navigation concepts for a planetary exploration vehicle. This focused study commenced with a requirements analysis that defined operational and functional requirements and constraints. Next, the physical system, its value system (evaluation parameters and design criteria) and the martian terrain design environment (surface models) were developed simultaneously. Mobility (the basic vehicle structure, suspension, and power train) and navigation (both global and local navigation including global reference, local terrain assessment, and guidance and control) concepts were developed independently and then integrated. Special attention was paid to the interdependency of navigation and locomotion in order to strike the appropriate balance between autonomy and mobility. Finally, the most promising concepts were subjected to a rigorous, structured evaluation process to derive the best candidate systems. To support the evaluation process, a three-layer computer model of the martian surface was developed. This model was based on the 1/64° Digital Elevation Model (DEM) of Mars developed by USGS Flagstaff. Local surface roughness based on measured martian slope distribution and power spectral density was superimposed on the DEM. Rocks based on H. Moore's distribution model were then added. To assess performance, selected concepts were modeled using DADSR from Computer Aided Software Inc., and simulations were run with the vehicle traversing the martian surface model, including one meter high vertical steps and one meter wide crevasses . During the course of this study, over 300 mobility concepts and more than 400 navigation concepts generated during a series of brainstorming sessions evolved into three promising candidate systems. The evolution of these systems is discussed; design details, conclusions and recommendations are presented.

  4. [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.

  5. 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.

  6. 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

  7. [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

  8. Teaching power concepts.

    PubMed

    Heineken, J; McCloskey, J C

    1985-01-01

    Concepts and strategies presented here provide nurses with a new perspective from which to analyze and interact with power dynamics. Understanding fundamental concepts of power will help nurses enjoy a more equal status and bargaining position within the community of health professionals and in health care delivery systems. As nurses integrate and utilize this content for enhancing professional practices and client services, our public image will also continue to be strengthened. In so doing, our power base and sphere of influence will also be broadened.

  9. Introduction: Bridging Concepts.

    PubMed

    Davids, Karel

    2015-12-01

    How can those in the history of science, history of technology, and economics communicate more with each other than they are accustomed? How can they become more globally oriented? While these three disciplines today have more convergent interests than in the past, there is still a large potential for further exchange and involvement to explore and exploit. The contributors to this Focus section discuss a number of concepts that may serve as tools to bring these three disciplines more closely together and ease their evolution in a less Eurocentric direction. These concepts include trading zones, interaction and formalization, production, and machines and self-organization. PMID:27024939

  10. 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.

  11. 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.

  12. Introduction: Bridging Concepts.

    PubMed

    Davids, Karel

    2015-12-01

    How can those in the history of science, history of technology, and economics communicate more with each other than they are accustomed? How can they become more globally oriented? While these three disciplines today have more convergent interests than in the past, there is still a large potential for further exchange and involvement to explore and exploit. The contributors to this Focus section discuss a number of concepts that may serve as tools to bring these three disciplines more closely together and ease their evolution in a less Eurocentric direction. These concepts include trading zones, interaction and formalization, production, and machines and self-organization.

  13. [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

  14. [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

  15. 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…

  16. 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…

  17. The Concept of Intelligence

    ERIC Educational Resources Information Center

    Hand, Michael

    2007-01-01

    Analyses of the ordinary concept of intelligence are few and far between in philosophical literature. Such analyses as there have been in recent years are heavily influenced by Ryle's suggestion that to act intelligently is to act "well" or "competently" in a particular domain. Here I show that there are serious problems with Ryle's account and…

  18. Team Building Concepts.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. It briefly explains how team building concepts affect businesses in new ways and how they help create an environment that provides job satisfaction for everyone and high-quality products for the…

  19. 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…

  20. The Mole Concept

    ERIC Educational Resources Information Center

    Duncan, I. M.; Johnstone, A. H.

    1973-01-01

    Reports a study of difficulties encountered by 14.5- to 15.0- year-old children in learning the mole concept with a programed instruction. Concludes that three respective disturbing factors were embedded in manipulation of molarity of solutions, balancing equations, and misapprehension that one mole of a compound always reacts with one mole of…

  1. 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…

  2. 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…

  3. 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…

  4. 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

  5. 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…

  6. 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…

  7. 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.

  8. 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.

  9. 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…

  10. Nursing Concepts. Teacher Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide contains the materials required to teach a course to prepare students for employment as practical nurses. The following topics are covered in seven instructional units: successful learning skills, positive self-concept, techniques for a balanced lifestyle, communication skills, legal and ethical issues, organizational and…

  11. 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)

  12. 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…

  13. Elaborating on Threshold Concepts

    ERIC Educational Resources Information Center

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-01-01

    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…

  14. 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…

  15. Concept Formation and Abstraction.

    ERIC Educational Resources Information Center

    Lunzer, Eric A.

    1979-01-01

    This paper examines the nature of concepts and conceptual processes and the manner of their formation. It argues that a process of successive abstraction and systematization is central to the evolution of conceptual structures. Classificatory processes are discussed and three levels of abstraction outlined. (Author/SJL)

  16. 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…

  17. What Is a Concept?

    ERIC Educational Resources Information Center

    Spitzer, Dean R.

    1975-01-01

    Article explores some of the key notions of the construct "concept" from the psychological and educational literature in order to demonstrate the need for standardization of definition and a more unified front in future investigations involving this important element in the study of cognition. (Author)

  18. Force Concept Inventory.

    ERIC Educational Resources Information Center

    Hestenes, David; And Others

    1992-01-01

    Reports the rationale, design, validation, and uses of the "Force Concept Inventory," an instrument to assess the students' beliefs on force. Includes results and implications of two studies that compared the inventory with the "Mechanics Baseline." Includes a copy of the instrument. (MDH)

  19. 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.

  20. 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…

  1. 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.

  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. The Concept of "Bildung"

    ERIC Educational Resources Information Center

    Varkoy, Oivind

    2010-01-01

    In this article I will discuss the originally German term and concept of Bildung. The reason why I, as a Scandinavian, find such a discussion both interesting and important is that the trend of instrumentalism in modern educational politics and pedagogical thinking (at least in Scandinavian countries) is problematic; that is, looking on knowledge…

  4. 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…

  5. 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…

  6. Nasal profile changes with le fort I maxillary advancement surgery.

    PubMed

    Marşan, Gülnaz; Hocaoğlu, Emre; Cura, Nil; Emekli, Ufuk

    2015-03-01

    Introduction : The purpose of this study was to quantify anteroposterior facial soft tissue changes with respect to underlying skeletal movements after Le Fort I maxillary advancement surgery by using lateral cephalograms taken before and after the operation. Materials and Methods : The study group consisted of 20 patients (10 women, 10 men; mean age 23.4 ± 1.4 years) having a Class III skeletal deformity caused by a retrognathic maxilla. All patients were treated by Le Fort I maxillary advancement osteotomy. Lateral cephalograms were taken before and 1.6 ± 0.4 years after surgery. Results : The anteroposterior position of A-point and anteroposterior position of maxillary incisor were significantly protracted (-2.69 ± 3.34 and -2.68 ± 3.21, respectively; P < .01). The nasal anteroposterior and superoinferior positions (NASALAP and NASALSI, respectively) were significantly changed (-2.70 ± 6.81, P < .01, and -2.55 ± 5.80, P < .05, respectively) and nasal elevation and protraction were observed after Le Fort I maxillary advancement surgery. Conclusions : The changes in anteroposterior and superoinferior positions of A-point were correlated with the nasal superoinferior position (r = -0.71 , P < .05; r = 0.72, P < .05) after Le Fort I maxillary advancement surgery.

  7. 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.

  8. 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 the…

  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. 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.

  11. 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)

  12. 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 so by enacting a restorative…

  13. LePera Career Activity Program. Final Report.

    ERIC Educational Resources Information Center

    Truby, Max E.

    The purpose of the research project was to determine the effectiveness of a comprehensive career orientation program in increasing awareness of self and of career opportunities in students of rural areas. Conducted with grades 7 and 8 in LePera school in Parker, Arizona from May 1973 to October 1974, the program provided occupational information…

  14. Computer Assisted Instruction: The Game "Le Choc des Multinationales."

    ERIC Educational Resources Information Center

    Cramer, Hazel

    "Le Choc de Multinationales" is a microcomputer game for students in an upper-level commercial French couse, to be played by two opponents, one of whom may be another student or the computer itself as a direct business competitor. The game's requirements for language use and knowledge of business and economics theory and principles are moderate,…

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. 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.

  20. 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

  1. C-CAMP, A closed cycle alkali metal power system

    SciTech Connect

    Wichner, R.P.; Hoffman, H.W.

    1988-01-01

    A concept is presented for a Closed-Cycle Alkali Metal (C-CAMP) power systems which utilizes the heat of reaction of an alkali metal and halogen compound to vaporize an alkali metal turbine fluid for a Rankine cycle. Unique features of the concept are (1) direct contact (heat exchange) between the reaction products and turbine fluid, and (2) a flow-through chemical reactor/boiler. The principal feasibility issues of the concept relate to the degree of cross-mixing of product and turbine fluid streams within the reactor-boiler. If proven feasible, the concept may be adapted to a range of fuel and turbine fluids and ultimately lead to thermal efficiencies in excess of 35%.

  2. Synthetic battery cycling techniques

    NASA Technical Reports Server (NTRS)

    Leibecki, H.; Thaller, L. H.

    1982-01-01

    The group of techniques that as a class are referred to as synthetic battery cycling are described with reference to spacecraft battery systems. Synthetic battery cycling makes use of the capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system.

  3. IFR fuel cycle

    SciTech Connect

    Battles, J.E.; Miller, W.E.; Lineberry, M.J.; Phipps, R.D.

    1992-04-01

    The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase, which includes completion of facility modifications and installation and cold checkout of process equipment. This paper reviews the development of the electrorefining pyroprocess, the design and construction of the facility for the hot demonstration, the design and fabrication of the equipment, and the schedule and initial plan for its operation.

  4. IFR fuel cycle

    SciTech Connect

    Battles, J.E.; Miller, W.E. ); Lineberry, M.J.; Phipps, R.D. )

    1992-01-01

    The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase, which includes completion of facility modifications and installation and cold checkout of process equipment. This paper reviews the development of the electrorefining pyroprocess, the design and construction of the facility for the hot demonstration, the design and fabrication of the equipment, and the schedule and initial plan for its operation.

  5. 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

  6. 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.

  7. 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. PMID:26716453

  8. 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.

  9. 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.

  10. Quantifying the Adaptive Cycle

    PubMed Central

    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. PMID:26716453

  11. 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 ...

  12. 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.

  13. 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…

  14. 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.

  15. 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…

  16. 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.

  17. The Use of Brainlab Navigation in Le Fort III Osteotomy.

    PubMed

    Wood, Jeyhan S; Purzycki, Adam; Thompson, Jim; David, Lisa R; Argenta, Louis C

    2015-05-01

    Le Fort III osteotomy is commonly used in the surgical correction of midface hypoplasia, specifically in patients with syndromic craniosynostosis. These osteotomies can be associated with significant complications, which are often the result of incomplete or inaccurate osteotomies. Brainlab, a technology first developed for neurosurgery, has been applied to numerous surgical subspecialties. The aim of this study was to report our initial experience using the Brainlab VectorVision2 and Brainlab Curve (Brainlab, Westchester, IL) as an intraoperative guidance system for osteotomy placement during Le Fort III advancement. Three pediatric patients with syndromic craniosynostosis and midface hypoplasia scheduled to undergo Le Fort III advancement were scanned preoperatively with 0.6-mm computed tomography cuts, which were then uploaded to the Brainlab system. All surgeries commenced with rigid fixation of the Brainlab registration device to the patient's skull. The navigation system was used intraoperatively to accurately determine osteotomy sites and trajectories. External distractors were placed without complication. Mean length of surgery was 331 minutes, and mean estimated blood loss was 500 mL. No transfusion was required with a mean postoperative hemoglobin of 8.3 g/dL. The application of Brainlab technology to Le Fort III advancement proved useful in establishing precise osteotomy lines and trajectories. Looking forward, this technology could be applied to a minimal dissection technique in order to avoid extensive blood loss. Further study would be needed to determine possible benefits such as reduced complications or operative time when using an intraoperative navigation system for image-guided osteotomy placement during Le Fort III advancement.

  18. 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

  19. 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,…

  20. US/CIS integrated NTRE concept

    SciTech Connect

    Bulman, M.J.; Culver, D.W.; McIlwain, M.C. ); D'yakov, E.K. ); Smetannikov, V.P. ); Rochow, R. )

    1993-01-10

    The team of Aerojet, Energopool and Babcock Wilcox has prepared a near-term Nuclear Thermal Rocket Engine (NTRE) concept that takes advantage of mature fuel technology developed in the former Soviet Union. This proven, advanced fuel appreciably shortens the development schedule of this engine for Moon and Mars exploration. Our near term engine has a number of features that provide safety, mission performance, cost and risk benefits, including: (1) High temperature, long life CIS fuel, (2) high pressure, recuperated topping cycle, (3) assured restart, (4) long life, cooled nozzle with thin inner wall, (5) long life turbopumps, (6) heat radiation and electrical power generation, and (7) component integration energy.

  1. US/CIS integrated NTRE concept

    NASA Astrophysics Data System (ADS)

    Bulman, Melvin J.; Culver, Donald W.; McIlwain, Melvin C.; D'Yakov, Evgeniy K.; Smetannikov, Vladimir P.; Rochow, Richard

    1993-01-01

    The team of Aerojet, Energopool and Babcock & Wilcox has prepared a near-term Nuclear Thermal Rocket Engine (NTRE) concept that takes advantage of mature fuel technology developed in the former Soviet Union. This proven, advanced fuel appreciably shortens the development schedule of this engine for Moon and Mars exploration. Our near term engine has a number of features that provide safety, mission performance, cost and risk benefits, including: (1) High temperature, long life CIS fuel, (2) high pressure, recuperated topping cycle, (3) assured restart, (4) long life, cooled nozzle with thin inner wall, (5) long life turbopumps, (6) heat radiation and electrical power generation, and (7) component integration energy.

  2. 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.

  3. A team approach to assisted conception treatment.

    PubMed

    Muirhead, Margaret; Lawton, Janet

    1998-01-01

    A programme to improve 'continuity of care' was initiated at Bourn Hall Clinic in direct response to patient demand to see the same doctors and nurses throughout assisted conception treatment cycles. A working party comprising individuals from all disciplines involved in assisted conception care was set up to review practices and aims and to establish an action plan. As a result, in 1996, a team approach to in vitro fertilization (IVF) and frozen embryo transfer (FET) treatment cycles was introduced at the clinic. The nursing staff were divided into two teams, each with a leader, an appropriate skill mix of full- and part-time nurses, and one full-time and one relief doctor. Treatment cycles were scheduled using pituitary downregulation with gonadotrophin-releasing hormone (GnRH) agonist when appropriate, and a programme was devised in which groups of 40--45 couples started treatment during the same 5 day period. Each couple was assigned to one of the teams and starting dates for each group were separated by 2 week intervals. The objectives of the working party were successfully achieved. The team approach to treating a finite number of couples provides a better opportunity for individualized care. Couples appreciate the advantages of continuity of care and the improved rapport with team staff. Forward planning of treatment cycles provides greater flexibility for incorporating clinic visits into patients' normal routines. Staff have benefited from increased job satisfaction due to greater involvement with couples from initial contact to the completion of treatment. The new working practice provides opportunities for training and research. Staff costs have been rationalized with benefits both to couples and to the business unit.

  4. 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)

  5. 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

  6. The NextGen Model Atmosphere Grid for 3000{le}T{sub eff}{le}10,000 K

    SciTech Connect

    Hauschildt, P.H.; Allard, F.; Baron, E.

    1999-02-01

    We present our NextGen Model Atmosphere grid for low-mass stars for effective temperatures larger than 3000 K. These LTE models are calculated with the same basic model assumptions and input physics as the VLMS part of the NextGen grid so that the complete grid can be used, e.g., for consistent stellar evolution calculations and for internally consistent analysis of cool star spectra. This grid is also the starting point for a large grid of detailed NLTE model atmospheres for dwarfs and giants. The models were calculated from 3000 to 10,000 K (in steps of 200 K) for 3.5{le}logthinspg{le}5.5 (in steps of 0.5) and metallicities of {minus}4.0{le}[M/H]{le}0.0. We discuss the results of the model calculations and compare our results to the Kurucz grid. Some comparisons to standard stars like Vega and the Sun are presented and compared with detailed NLTE calculations. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

  7. Fruit quality of transgenic tomatoes with suppressed expression of LeETR1 and LeETR2 genes.

    PubMed

    Bao, Bili; Ke, Leqin; Jiang, Jianmei; Ying, Tiejin

    2007-01-01

    Tomato fruit is renowned for its high concentration of phyto-nutrients such as lycopene and carotenoids, overall contribution to nutrition and human health. The effect of antisense suppression of ethylene receptor genes LeETR1 and LeETR2 over the quality of tomato fruit was investigated in this paper. During the different stages of ripening, the fruit of antisense transgenic tomatoes of ale1 and ale2, compared to their wild type B1, showed higher total soluble solids, acidity and electrolytes accumulations and color development; lower fruit firmness, fruit viscosity and fruit elasticity. However, no significant difference of Vc content, total sugar, fruit pH value and fruit pigments between transgenic lines and B1 were noticed. ale1 and ale2 showed shortened shelf life. The data suggest that fruit with suppressed LeETR1 and LeETR2 genes expression have stronger ethylene response, which accelerate fruit ripening and greatly altered tomato variety characteristics.

  8. 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.

  9. 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…

  10. A Field Course Teaching Research Concepts in Environmental Geochemistry.

    ERIC Educational Resources Information Center

    Brown, Foster; De Lacerda, Luiz Drude

    1986-01-01

    Describes a graduate field course taught in Brazil that uses a system concept and the geochemical cycle as unifying paradigms to study various environments. Emphasizes the acquisition of techniques of integrated observation, using operational definitions, measurement scales, and a priori hypotheses. (Author/TW)

  11. 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.

  12. [Loneliness: a concept analysis].

    PubMed

    Huang, Yi-Jen; Wang, Kwua-Yun; Chen, Chin-Mi

    2010-10-01

    Loneliness is a kind of mood that most people have experienced at one time or another. Individual experiences with loneliness as joyful or painful saturation are highly personal and can be defined only in such a context. Loneliness has differing effects on the long-term health of individuals. Although loneliness impacts greatly on individual health, there is little in the literature related to concept analyses of loneliness. The purpose of this article was to use Walker and Avant's (2005) concept analysis methodology to review conceptual definitions of loneliness, characteristics, antecedents and consequences; construct examples and establish empirical measurements. Results indicate that defining attributes of loneliness included an individual's subjective mood, descriptions of aloneness, depression, desolation or empty feelings, and the perception of the spirit isolated from others. It is hoped that nursing staffs may better understand loneliness through this article, provide an assessment of client loneliness as early as possible, and enhance client health condition. PMID:20878616

  13. Advanced space propulsion concepts

    NASA Technical Reports Server (NTRS)

    Lapointe, Michael R.

    1993-01-01

    The NASA Lewis Research Center has been actively involved in the evaluation and development of advanced spacecraft propulsion. Recent program elements have included high energy density propellants, electrode less plasma thruster concepts, and low power laser propulsion technology. A robust advanced technology program is necessary to develop new, cost-effective methods of spacecraft propulsion, and to continue to push the boundaries of human knowledge and technology.

  14. 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.

  15. Artist's Concept of Voyager

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This artist's concept of the Voyager spacecraft with its antenna pointing to Earth. The identical Voyager spacecraft are three-axis stabilized systems that use celestial or gyro referenced attitude control to maintain pointing of the high-gain antennas toward Earth. The prime mission science payload consisted of 10 instruments (11 investigations including radio science). Only five investigator teams are still supported, though data are collected for two additional instruments.

  16. 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.

  17. 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.

  18. The Fuego System Concept

    NASA Astrophysics Data System (ADS)

    Martín-rico, Cristóbal; Gonzalo, Jesús; Mariani, Andrea; Leibrandt, Wolfgang

    FUEGO is a satellite system intended to provide the firefighting forces in the world with early fire warning and fire monitoring capabilities. It is being conceived with the users, by fostering continuous user direction of the development process. This system concept is presented. We present the user requirements that have evolved from user consultation and have been confirmed in the First FUEGO Users Conference in Madrid. The sensor arrangement is discussed including the sort of algorithm envisaged and the necessary supporting spectral bands and sensitivity. Technological aspects are reviewed. The operational concept is briefly described. The architecture is shown to be flexible and adapted to user expectations. From the operational concept the satellite and ground segment requirements and design are presented, to show the feasibility in technical and programmatic terms. The main system issues are analysed for criticality and basic conclusions are derived. A summary of cost benefit analysis is presented. A satellite system is therefore proposed as an operational mission to support the forest firefighting activity.

  19. LM-MHD conversion: Cycle analysis

    SciTech Connect

    Mathes, R.; Thibault, J.P.; Pisoni, C.; Tagliafico, L.

    1994-01-01

    The LMMHD (Liquid Metal - MagnetoHydroDynamic) energy conversion offers several possible development of novel thermodynamic concepts, which entail isothermal thermodynamic expansions. Numerous basic conceptual arrangements of the various components of a conversion loop have been presented since the sixties. This variety of concepts is more or less connected to the working conditions, such as hot and cold source temperatures, and to the environment, for instance space or earth applications. The present work is developed with reference to the use of a high temperature coal burner. In such specific case a {open_quotes}conventional{close_quotes} LMMHD conversion loop alone is not suitable to cover the entire temperature difference between the hot ({approximately}1400K) and the cold ({approximately}300K) sources. Thus it is convenient to combine the LMMHD conversion process (operating as a topping cycle), with a bottoming cycle, which may be a conventional Rankine cycle. In this paper several possible solutions of combined power plants are compared on the basis of both energetic (i.e. first law of thermodynamics) and exergetic (i.e. second law) analysis.

  20. The 11-year cycle in human births

    NASA Astrophysics Data System (ADS)

    Randall, Walter; Moos, Walter S.

    1993-06-01

    The annual numbers of human births were analyzed with regard to an 11-year cycle. The annual values were obtained from seven different regions: Australia, Germany, England and Wales, New Zealand, Japan, Switzerland, and the USA. Fifty-five annual values were obtained from each region for the years 1930 to 1984, comprising approximately five sunspot cycles. For each region the annual values were formed into 5 by 11 matrices; the eleven column means obtained were standardized, and plotted. A periodic regression technique, utilizing the fitting functions of the Fourier series, was used to evaluate the temporal order in the column means. Eleven-year rhythms were found and compared with solar and geophysical variables. Correlations were found with sunspots and solar flares, with terrestrial measures of magnetic disturbances (the magnetic indices derived from the K-index), and with temperature. The correlation of conceptions with the 11-year solar cycle may be a potential guide in the selection of further variables for the control and regulation of the rhythms in human conceptions.

  1. Kalina cycle application to gas turbine combined cycles

    SciTech Connect

    Bjorge, R.W.; Corman, J.C.; Smith, R.W.

    1995-12-31

    Gas turbine-based combined cycles have gained broad market acceptance due to their favorable economics, high efficiency and excellent environmental performance. Combined-cycle performance improvements have tracked the rapid advance of gas turbine technology. The introduction of the steam-cooled STAG 107H and 109H combined-cycle systems with their 60% net plant efficiency capability is the latest step in this trend. High-efficiency steam bottoming cycles have also advanced, with the current state-of-the-art being the three-pressure reheat cycle. The Kalina Cycle utilizing a mixture of ammonia and water as the working fluid promises to further continue these combined cycle-performance improvements with dramatic changes in the bottoming cycle. These improvements are due to non-isothermal heat acquisition and heat rejection, as well as internal heat recuperation, which reduce losses of thermodynamic availability, or exergy, in the cycle. This paper discusses the application of the Kalina Cycle to gas turbine-based combined cycles, including system design and performance characteristics. It compares Kalina Cycle performance and economics with that of a state-of-the-art steam bottoming cycle, showing the potential economic advantages of this innovative cycle in combined-cycle applications. Several variants of the Kalina Cycle system and the Distillation Condensation Subsystem (DCSS), which replaces the condenser as the heat rejection and recuperation system of the Kalina Cycle, have been studied. Results show that the Kalina Cycle can enhance the gas turbine bottoming cycle power output by over 15% when compared with a three-pressure reheat Rankine bottoming cycle. This yields an efficiency improvement of 2-3 percentage points, a significant advance in the state-of-the-art. Based on these substantial performance gains, GE is pursuing the commercialization of the Kalina Cycle for combined-cycle applications under a worldwide exclusive license from Exergy, Inc.

  2. Helium process cycle

    SciTech Connect

    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.

  3. Helium process cycle

    SciTech Connect

    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.

  4. 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.

  5. 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.

  6. Connecting the nucleolus to the cell cycle and human disease.

    PubMed

    Tsai, Robert Y L; Pederson, Thoru

    2014-08-01

    Long known as the center of ribosome synthesis, the nucleolus is connected to cell cycle regulation in more subtle ways. One is a surveillance system that reacts promptly when rRNA synthesis or processing is impaired, halting cell cycle progression. Conversely, the nucleolus also acts as a first-responder to growth-related stress signals. Here we review emerging concepts on how these "infraribosomal" links between the nucleolus and cell cycle progression operate in both forward and reverse gears. We offer perspectives on how new cancer therapeutic designs that target this infraribosomal mode of cell growth control may shape future clinical progress.

  7. 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.

  8. 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.

  9. 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.

  10. The urea cycle disorders.

    PubMed

    Helman, Guy; Pacheco-Colón, Ileana; Gropman, Andrea L

    2014-07-01

    The urea cycle is the primary nitrogen-disposal pathway in humans. It requires the coordinated function of six enzymes and two mitochondrial transporters to catalyze the conversion of a molecule of ammonia, the α-nitrogen of aspartate, and bicarbonate into urea. Whereas ammonia is toxic, urea is relatively inert, soluble in water, and readily excreted by the kidney in the urine. Accumulation of ammonia and other toxic intermediates of the cycle lead to predominantly neurologic sequelae. The disorders may present at any age from the neonatal period to adulthood, with the more severely affected patients presenting earlier in life. Patients are at risk for metabolic decompensation throughout life, often triggered by illness, fasting, surgery and postoperative states, peripartum, stress, and increased exogenous protein load. Here the authors address neurologic presentations of ornithine transcarbamylase deficiency in detail, the most common of the urea cycle disorders, neuropathology, neurophysiology, and our studies in neuroimaging. Special attention to late-onset presentations is given.

  11. 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.

  12. Breaking a vicious cycle.

    PubMed

    Hayes, Daniel F; Allen, Jeff; Compton, Carolyn; Gustavsen, Gary; Leonard, Debra G B; McCormack, Robert; Newcomer, Lee; Pothier, Kristin; Ransohoff, David; Schilsky, Richard L; Sigal, Ellen; Taube, Sheila E; Tunis, Sean R

    2013-07-31

    Despite prodigious advances in tumor biology research, few tumor-biomarker tests have been adopted as standard clinical practice. This lack of reliable tests stems from a vicious cycle of undervaluation, resulting from inconsistent regulatory standards and reimbursement, as well as insufficient investment in research and development, scrutiny of biomarker publications by journals, and evidence of analytical validity and clinical utility. We offer recommendations designed to serve as a roadmap to break this vicious cycle and call for a national dialogue, as changes in regulation, reimbursement, investment, peer review, and guidelines development require the participation of all stakeholders. PMID:23903752

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Synthetic battery cycling techniques

    NASA Technical Reports Server (NTRS)

    Leibecki, H. F.; Thaller, L. H.

    1982-01-01

    Synthetic battery cycling makes use of the fast growing capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system. The group of techniques that as a class have been referred to as Synthetic Battery Cycling is developed in part to try to bridge the gap of understanding that exists between single cell characteristics and battery system behavior.

  18. Understanding the petrochemical cycle

    SciTech Connect

    Sedriks, W.

    1996-10-01

    The presentation will examine the nature of the supply, demand and profitability cycles that appear to be endemic in the petrochemical industry. The focus will be on the underlying factors that cause cyclicality. Data for ethylene and first line derivatives will be used both to provide quantitative illustrations of the magnitude of the cyclical effects and to give an improved perspective on the forces that drive cylicality. We will also examine to what extent cycle timing may be predictable, and present some scenario based projections.

  19. 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

  20. 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

  1. Menstrual cycle effects on attitudes toward romantic kissing.

    PubMed

    Wlodarski, Rafael; Dunbar, Robin I M

    2013-12-01

    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.

  2. Safeguards operations in the integral fast reactor fuel cycle

    SciTech Connect

    Goff, K.M.; Benedict, R.W.; Brumbach, S.B.; Dickerman, C.E.; Tompot, R.W.

    1994-08-01

    Argonne National Laboratory is currently demonstrating the fuel cycle for the Integral Fast Reactor (IFR), an advanced reactor concept that takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel-cycle economics, environmental protection, and safeguards. The IFR fuel cycle employs a pyrometallurgical process using molten salts and liquid metals to recover actinides from spent fuel. The safeguards aspects of the fuel cycle demonstration must be approved by the United States Department of Energy, but a further goal of the program is to develop a safeguards system that could gain acceptance from the Nuclear Regulatory Commission and International Atomic Energy Agency. This fuel cycle is described with emphasis on aspects that differ from aqueous reprocessing and on its improved safeguardability due to decreased attractiveness and diversion potential of all process streams, including the fuel product.

  3. 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

  4. 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.

  5. 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. PMID:9565906

  6. 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.

  7. 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…

  8. Teacher Self-Concept and Student Self-Concept.

    ERIC Educational Resources Information Center

    Edeburn, Carl E.; Landry, Richard G.

    This research concerns the changes in children's levels of self-concept over an academic year and whether these changes are related to the self-concept of their teachers. Data were generated from 16 self-contained classrooms in the third, fourth, and fifth grades of a midwestern city. Students' self-concepts were measured by the primary form of…

  9. Threshold Concepts and Conceptions: Student Learning in Introductory Management Courses

    ERIC Educational Resources Information Center

    Wright, April L.; Gilmore, Anne

    2012-01-01

    This article explores how insights from the broader education literature on threshold concepts and conceptions can be applied to improve the teaching of undergraduate introductory management courses. The authors propose that these courses are underpinned by the threshold conception, or "underlying game," that management is a practice informed by…

  10. DentLE. The Dental Learning Environment: a prototype demonstration.

    PubMed Central

    Vullo, R. P.; Eisner, J.

    1992-01-01

    DentLE, the Dental Learning Environment is a hypermedia software system being prototyped as part of a research and development project at the State University of New York at Buffalo School of Dental Medicine. The design seeks to reach beyond single discipline software or cases, and integrate a range of patient problems within a comprehensive dental knowledge base. The approach is to use computer and hypermedia technology to weave together the disciplines of dentistry so that learning occurs in relation to patients, as they appear in the real world. The DentLE system prototype allows the learner to explore information in all the disciplines related to patient problems, as well as other information including "blind alleys" and results of curiosity. PMID:1482989

  11. 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

  12. 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.

  13. 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.

  14. Paraterraforming - The worldhouse concept

    NASA Astrophysics Data System (ADS)

    Taylor, Richard L. S.

    1992-08-01

    This paper discusses 'paraterraforming' as a means of creating and maintaining habitable environments on other planets. The 'worldhouse' concept of paraterraforming can be formulated within the existing boundaries of technological knowledge and can provide a quasi-unconstrained global habitable environment at significantly lower levels of materials requirement and economic cost. Construction can proceed on a modular basis. A coarse-grained assessment of the possibilities of paraterraforming Mars is presented. It is suggested that the establishment of a fully habitable worldhouse environment on the planet Mercury would be a much less difficult undertaking than taerraforming Venus and could be economically important for the human exploitation of the solar system.

  15. CONCEPT ANALYSIS: AGGRESSION

    PubMed Central

    Liu, Jianghong

    2006-01-01

    The concept of aggression is important to nursing because further knowledge of aggression can help generate a better theoretical model to drive more effective intervention and prevention approaches. This paper outlines a conceptual analysis of aggression. First, the different forms of aggression are reviewed, including the clinical classification and the stimulus-based classification. Then the manifestations and measurement of aggression are described. Finally, the causes and consequences of aggression are outlined. It is argued that a better understanding of aggression and the causal factors underlying it are essential for learning how to prevent negative aggression in the future. PMID:15371137

  16. 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.

  17. Sequence diversity and enzyme activity of ferric-chelate reductase LeFRO1 in tomato.

    PubMed

    Kong, Danyu; Chen, Chunlin; Wu, Huilan; Li, Ye; Li, Junming; Ling, Hong-Qing

    2013-11-20

    Ferric-chelate reductase which functions in the reduction of ferric to ferrous iron on root surface is a critical protein for iron homeostasis in strategy I plants. LeFRO1 is a major ferric-chelate reductase involved in iron uptake in tomato. To identify the natural variations of LeFRO1 and to assess their effect on the ferric-chelate reductase activity, we cloned the coding sequences of LeFRO1 from 16 tomato varieties collected from different regions, and detected three types of LeFRO1 (LeFRO1(MM), LeFRO1(Ailsa) and LeFRO1(Monita)) with five amino acid variations at the positions 21, 24, 112, 195 and 582. Enzyme activity assay revealed that the three types of LeFRO1 possessed different ferric-chelate reductase activity (LeFRO1(Ailsa) > LeFRO1(MM) > LeFRO1(Monita)). The 112th amino acid residue Ala of LeFRO1 is critical for maintaining the high activity of ferric-chelate reductase, because modification of this amino acid resulted in a significant reduction of enzyme activity. Further, we showed that the combination of the amino acid residue Ile at the site 24 with Lys at the site 582 played a positive role in the enzyme activity of LeFRO1. In conclusion, the findings are helpful to understand the natural adaptation mechanisms of plants to iron-limiting stress, and may provide new knowledge to select and manipulate LeFRO1 for improving the iron deficiency tolerance in tomato.

  18. 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.

  19. LeCroy MQT300A - charge to time converter

    SciTech Connect

    Yamrone, B.; Roberts, K.; Kelly, J.

    1997-12-31

    The MQT300A was developed to offer high resolution (12 bit) and wide dynamic range (18 bit) with reasonable cost, high density and fast conversion time (< 10 {mu}s). The reduced conversion time has allowed its first users the option to choose whether or not to develop a fast clear strategy as part of their trigger system. It can also be used for chamber-mounted applications allowing compact digital data cabling to the remote TDC. The MQT300A is a custom development produced in collaboration with the BELLE collaboration at KEK and the CLEO group at Cornell. In this collaboration Cornell and KEK were partners with LeCroy in both the specification and evaluation of the first prototypes. LeCroy has been responsible for the remainder of the project. The MQT300A is available in LeCroy modules and also as a separate monolithic. The MQT300A was designed to take advantage of the latest generation of multi-hit TDCs, for example the LeCroy 1877S FASTBUS ADC. The 1877S was specifically optimized to improve conversion time and to intelligently minimize the data record size for the MQT300A application. A prototype part was designed and fabricated using a custom bipolar process. Though fully functional it did not meet several important performance specifications. A reiteration with significant redesign of two sections resulted in a part that meets all specifications. The unique encoding algorithm used to provide auto-ranging has had a U.S. patent allowed. The part is now commercially available in production volumes.

  20. Cycling/dispatching power plants

    SciTech Connect

    Makansi, J.

    1994-02-01

    This article examines the effect cycling capability has on a power systems plants and the tradeoffs in performance that may occur. The topics of this article include cycling capability, control and training tools, combined cycles, steam turbine selection, protection against water induction, plant staffing, boiler/steam turbines, full turbine bypasses, cycling of CFB boilers, generators, and environmental control system uses to monitor performance.

  1. 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.

  2. Stellar magnetic cycles

    NASA Astrophysics Data System (ADS)

    Baliunas, S. L.

    2004-05-01

    Is hope for understanding the solar magnetic cycle to be found in stars? Observations of stars with significant sub-surface convective zones -- masses smaller than about 1.5 solar masses on the lower main sequence and many types of cool, post-main-sequence stars -- indicate the presence of surface and atmospheric inhomogeneities analogous to solar magnetic features, making stellar magnetic activity a cosmically widespread phenomenon. Observations have been made primarily in visible wavelengths, and important information has also been derived from the ultraviolet and x-ray spectrum regions. Interannual to interdecadal variability of spectrum indicators of stellar magnetic features is common, and in some cases similar in appearance to the 11-year sunspot cycle. Successful models of the physical processes responsible for stellar magnetic cycles, typically cast as a magnetohydrodynamic dynamo, require advances in understanding not only convection but also the magnetic field's interaction with it. The observed facts that underpin the hope for models will be summarized. Properties of stellar magnetic cycles will be compared and contrasted with those of the sun, including inferences from paleo-environmental reservoirs that contain information on solar century- to millennial-scale magnetic variability. Partial support of this research came from NASA NAG5-7635, NRC COBASE, CRDF 322, MIT-MSG 5710001241, JPL 1236821, AF 49620-02-1-0194, Richard Lounsberry Foundation, Langley-Abbot, Rollins, Scholarly Studies and James Arthur Funds (Smithsonian Institution) and several generous individuals.

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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...

  8. Rapid cycling superconducting magnets

    NASA Astrophysics Data System (ADS)

    Fabbricatore, P.; Farinon, S.; Gambardella, U.; Greco, M.; Volpini, G.

    2006-04-01

    The paper deals with the general problematic related to the development of fast cycled superconducting magnets for application in particle accelerator machines. Starting from the requirements of SIS300 synchrotron under design at GSI and an envisaged future Super-SPS injector at CERN, it is shown which developments are mandatory in the superconducting wire technology and in the magnet design field.

  9. Stirling cycle piston engine

    SciTech Connect

    Morgan, G. R.

    1985-02-12

    This device is an improvement over the conventional type of Stirling cycle engine where the expander piston is connected to a crankshaft and the displacer piston is connected to the same or another crankshaft for operation. The improvement is based on both the expansion and displacer pistons being an integral unit having regenerating means which eliminate the mechanisms that synchronize the regeneration mode.

  10. [A new technic for LE cell formation. Preliminary report].

    PubMed

    Gómez-Estrada, H; Fernández-Quintero, P; Toro-Pérez, A; Arellando-Blanco, J; Ochoa Díaz-López, H; Tapia-Arizmendi, G

    1976-01-01

    In special designed vials using coverslides glued to segments of polyethilene test tubes of 0.15 ml of fibrin free blood were incubated during 45 min to 37 degrees C in a humid chamber. Blood samples were obtained from patients with disseminated Lupus erythematosus (DLE) and normal subjects (N). Adhered polymorpho-nuclear cells (PNC) to glass were washed with Hank's solution; immediately 0.15 ml of DLE or N serum containing 5X10(6) lymphocytes (L) were added to culture cells and incubated at 37 degrees C during 30 min. Lymphocytes were previously incubated at 37 degrees C during 30 min with either N serum or DLE serum. Thereafter the segment of polyethilene test tube was detached from coverslides and cells attached to glass was washed with Hank's solution and stained with Wright solution. PMN of DLE and N in presence of L of DLE and N incubated with fresh serum of DLE formed 5 to 15% of LE cells. Determining factor for LE cells formation is the serum of DLE. Slides contained only PMN and LE cells which make easy the observation of results. All possible combinations with PMN and DLE serum and N serum allowed inclusion of several negative or positive control groups.

  11. Mandibular growth following Le Fort I osteotomy in adolescent monkeys.

    PubMed

    Nanda, R; Bouayad, O; Topazian, R G

    1987-06-01

    Le Fort I osteotomy with anterior and superior repositioning of the maxilla was performed on adolescent Macaca fascicularis monkeys to study its effect on the subsequent growth and remodeling changes of the mandible. Six adolescent Macaca fascicularis monkeys were randomly divided into two surgical groups and eight others served as controls. Group I animals underwent a Le Fort I advancement and Group II animals experienced a Le Fort I advancement and impaction. All monkeys received tantalum implants in the anterior part of the cranial base, on opposite sides of craniofacial sutures and in multiple sites of the maxilla and mandible. The immediate postsurgical occlusion of all experimental animals was a Class II molar relationship. The animals were followed for up to 12 months postoperatively. Analysis of cephalometric head films taken at monthly intervals showed that both the maxilla and the mandible of all experimental monkeys grew in a coordinated fashion, although the amount, rate, and direction of growth varied between control and experimental animals as well as between Group I and Group II animals. The largest increments and rates of growth were observed in the control animals, Group I animals, and Group II animals, respectively. This study indicates that the growth changes in both maxilla and mandible are related to the extent of injury caused by maxillary surgery. The results also showed that although the surgical procedures were performed in the maxilla, mandibular growth was significantly modulated by the surgically changed maxillary environment.

  12. Airborne pollen and spores of León (Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-González, Delia; Suarez-Cervera, María; Díaz-González, Tomás; Valencia-Barrera, Rosa María

    1993-06-01

    A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter, Pinus and Quercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores ( Penicillium, Aspergillus and Cladosporium) as well as Dictyospores ( Alternaria) were the most abundant; Puccinia was common in the air in August. Fluctuations in the total pollen and spores m3 of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.

  13. Concept Convergence in Empirical Domains

    NASA Astrophysics Data System (ADS)

    Ontañón, Santiago; Plaza, Enric

    How to achieve shared meaning is a significant issue when more than one intelligent agent is involved in the same domain. We define the task of concept convergence, by which intelligent agents can achieve a shared, agreed-upon meaning of a concept (restricted to empirical domains). For this purpose we present a framework that, integrating computational argumentation and inductive concept learning, allows a pair of agents to (1) learn a concept in an empirical domain, (2) argue about the concept's meaning, and (3) reach a shared agreed-upon concept definition. We apply this framework to marine sponges, a biological domain where the actual definitions of concepts such as orders, families and species are currently open to discussion. An experimental evaluation on marine sponges shows that concept convergence is achieved, within a reasonable number of interchanged arguments, and reaching short and accurate definitions (with respect to precision and recall).

  14. Let's Teach Life Insurance Concepts

    ERIC Educational Resources Information Center

    Coleman, Larry D.

    1973-01-01

    The author presents arguments for teaching life insurance concepts as part of the business education curriculum. He also presents specific facts, "knowledges," understandings, and concepts as part of the learning process. (AG)

  15. 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

  16. 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.

  17. ATR performance modeling concepts

    NASA Astrophysics Data System (ADS)

    Ross, Timothy D.; Baker, Hyatt B.; Nolan, Adam R.; McGinnis, Ryan E.; Paulson, Christopher R.

    2016-05-01

    Performance models are needed for automatic target recognition (ATR) development and use. ATRs consume sensor data and produce decisions about the scene observed. ATR performance models (APMs) on the other hand consume operating conditions (OCs) and produce probabilities about what the ATR will produce. APMs are needed for many modeling roles of many kinds of ATRs (each with different sensing modality and exploitation functionality combinations); moreover, there are different approaches to constructing the APMs. Therefore, although many APMs have been developed, there is rarely one that fits a particular need. Clarified APM concepts may allow us to recognize new uses of existing APMs and identify new APM technologies and components that better support coverage of the needed APMs. The concepts begin with thinking of ATRs as mapping OCs of the real scene (including the sensor data) to reports. An APM is then a mapping from explicit quantized OCs (represented with less resolution than the real OCs) and latent OC distributions to report distributions. The roles of APMs can be distinguished by the explicit OCs they consume. APMs used in simulations consume the true state that the ATR is attempting to report. APMs used online with the exploitation consume the sensor signal and derivatives, such as match scores. APMs used in sensor management consume neither of those, but estimate performance from other OCs. This paper will summarize the major building blocks for APMs, including knowledge sources, OC models, look-up tables, analytical and learned mappings, and tools for signal synthesis and exploitation.

  18. [The concept of health].

    PubMed

    Segre, M; Ferraz, F C

    1997-10-01

    Objections to the present WHO (World Health Organization) definition of HEALTH, as "the state of perfect physical, mental and social well-being", are expressed. It is considered to be anachronistic, first because it aims at perfection which is unaltainelle because of district personality characteristics. As the main support for this idea, the necessary renunciation of part of man's drive to liberty in exchange for the lesser insecurity provided by social life (Freud, Castoriadis and McDougall), is groted. The validity of distinguishing between "soma", "psyche" and "society" is questioned and the concept of the "integrated man", alluding to Pierre Marty and to Freud himself is adapted, and situations are recalled in which the interaction of the three aspects mentioned above is actually evident. Finally, the notion of the quality of life, in accordance with an antipositivistic taken from Bion, point of view, is discussed, and the concept that reality is that of each human being, is adapted. This priority and the proposal to rescue subjectivism which was also observed by Foucault when he studied mental disease, leads to a last criticism of the present definition of health, based exclusively on external, objective evaluations. PMID:9629735

  19. Modular reflector concept study

    NASA Technical Reports Server (NTRS)

    Vaughan, D. H.

    1981-01-01

    A study was conducted to evaluate the feasibility of space erecting a 100 meter paraboloidal radio frequency reflector by joining a number of individually deployed structural modules. Three module design concepts were considered: (1) the deployable cell module (DCM); (2) the modular paraboloidal erectable truss antenna (Mod-PETA); and (3) the modular erectable truss antenna (META). With the space shuttle (STS) as the launch system, the methodology of packaging and stowing in the orbiter, and of dispensing, deploying and joining, in orbit, were studied and the necessary support equipment identified. The structural performance of the completed reflectors was evaluated and their overall operational capability and feasibility were evaluated and compared. The potential of the three concepts to maintain stable shape in the space environment was determined. Their ability to operate at radio frequencies of 1 GHz and higher was assessed assuming the reflector surface to consist of a number of flat, hexagonal facets. A parametric study was performed to determine figure degradation as a function of reflector size, flat facet size, and f/D ratio.

  20. PRSEUS Structural Concept Development

    NASA Technical Reports Server (NTRS)

    Velicki, Alex; Jegley, Dawn

    2014-01-01

    A lighter, more robust airframe is one of the key technological advancements necessary for the successful launch of any large next-generation transport aircraft. Such a premise dictates that considerable improvements beyond current state-of-the-art aluminum structures is needed, and that improvements of this magnitude will require an extensive use of composite materials that are not only lightweight, but also economical to produce. To address this challenge, researchers at NASA and The Boeing Company are developing a novel structural concept called the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) under the Environmentally Responsible Aviation (ERA) Project. It is an integrally stiffened panel concept that is stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. In addition to improved structural performance, an important facet of this unique arrangement of stitched carbon fibers is its innovative manufacturing method that has the potential to lower fabrication costs by eliminating fasteners and autoclave cures. The rationale and development status for this new approach forms the basis of the work described in this paper. The test specimens described herein were fabricated, or are currently being fabricated, by The Boeing Company, while the structural analyses and testing tasks are being performed by NASA and Boeing personnel.