Science.gov

Sample records for advanced conceptual models

  1. Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

    SciTech Connect

    Nicholl, Michael J.

    2006-07-10

    The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock.

  2. A spirit-focused conceptual model of nursing for the advanced practice nurse.

    PubMed

    Swanson, C S

    1995-01-01

    A spirit-focused conceptual model of nursing views the person as a spiritual being whose life and purpose arise from a personal relationship with God. The individual's definition of God determines how he or she responds to stimuli, sets goals, and establishes purpose in life. Consequently, this definition influences the professional nursing relationship, and the nurse's and patient's concepts of health and perceptions of the environment. The pediatric nurse practitioner and client are the primary examples of practice examined in this study.

  3. Reactor physics methods, models, and applications used to support the conceptual design of the Advanced Neutron Source

    SciTech Connect

    Gehin, J.C.; Worley, B.A.; Renier, J.P.; Wemple, C.A.; Jahshan, S.N.; Ryskammp, J.M.

    1995-08-01

    This report summarizes the neutronics analysis performed during 1991 and 1992 in support of characterization of the conceptual design of the Advanced Neutron Source (ANS). The methods used in the analysis, parametric studies, and key results supporting the design and safety evaluations of the conceptual design are presented. The analysis approach used during the conceptual design phase followed the same approach used in early ANS evaluations: (1) a strong reliance on Monte Carlo theory for beginning-of-cycle reactor performance calculations and (2) a reliance on few-group diffusion theory for reactor fuel cycle analysis and for evaluation of reactor performance at specific time steps over the fuel cycle. The Monte Carlo analysis was carried out using the MCNP continuous-energy code, and the few- group diffusion theory calculations were performed using the VENTURE and PDQ code systems. The MCNP code was used primarily for its capability to model the reflector components in realistic geometries as well as the inherent circumvention of cross-section processing requirements and use of energy-collapsed cross sections. The MCNP code was used for evaluations of reflector component reactivity effects and of heat loads in these components. The code was also used as a benchmark comparison against the diffusion-theory estimates of key reactor parameters such as region fluxes, control rod worths, reactivity coefficients, and material worths. The VENTURE and PDQ codes were used to provide independent evaluations of burnup effects, power distributions, and small perturbation worths. The performance and safety calculations performed over the subject time period are summarized, and key results are provided. The key results include flux and power distributions over the fuel cycle, silicon production rates, fuel burnup rates, component reactivities, control rod worths, component heat loads, shutdown reactivity margins, reactivity coefficients, and isotope production rates.

  4. Model Building for Conceptual Change

    ERIC Educational Resources Information Center

    Jonassen, David; Strobel, Johannes; Gottdenker, Joshua

    2005-01-01

    Conceptual change is a popular, contemporary conception of meaningful learning. Conceptual change describes changes in conceptual frameworks (mental models or personal theories) that learners construct to comprehend phenomena. Different theories of conceptual change describe the reorganization of conceptual frameworks that results from different…

  5. Conceptual IT model

    NASA Astrophysics Data System (ADS)

    Arnaoudova, Kristina; Stanchev, Peter

    2015-11-01

    The business processes are the key asset for every organization. The design of the business process models is the foremost concern and target among an organization's functions. Business processes and their proper management are intensely dependent on the performance of software applications and technology solutions. The paper is attempt for definition of new Conceptual model of IT service provider, it could be examined as IT focused Enterprise model, part of Enterprise Architecture (EA) school.

  6. Advancing a Conceptual Model of Evidence-Based Practice Implementation in Public Service Sectors

    PubMed Central

    Hurlburt, Michael; Horwitz, Sarah McCue

    2010-01-01

    Implementation science is a quickly growing discipline. Lessons learned from business and medical settings are being applied but it is unclear how well they translate to settings with different historical origins and customs (e.g., public mental health, social service, alcohol/drug sectors). The purpose of this paper is to propose a multi-level, four phase model of the implementation process (i.e., Exploration, Adoption/Preparation, Implementation, Sustainment), derived from extant literature, and apply it to public sector services. We highlight features of the model likely to be particularly important in each phase, while considering the outer and inner contexts (i.e., levels) of public sector service systems. PMID:21197565

  7. Mental Models, Conceptual Models, and Modelling.

    ERIC Educational Resources Information Center

    Greca, Ileana Maria; Moreira, Marco Antonio

    2000-01-01

    Reviews science education research into representations constructed by students in their interactions with the world, its phenomena, and artefacts. Features discussions of mental models, conceptual models, and the activity of modeling. (Contains 30 references.) (Author/WRM)

  8. Ecosystem conceptual model- Mercury

    USGS Publications Warehouse

    Alpers, Charles N.; Eagles-Smith, Collin A.; Foe, Chris; Klasing, Susan; Marvin-DiPasquale, Mark C.; Slotton, Darell G.; Windham-Myers, Lisamarie

    2008-01-01

    mercury conceptual model and its four submodels (1. Methylation, 2. Bioaccumulation, 3. Human Health Effects, and 4. Wildlife Heath Effects) can be used to understand the general relationships among drivers and outcomes associated with mercury cycling in the Delta. Several linkages between important drivers and outcomes have been identified as important but highly uncertain (i.e. poorly understood). For example, there may be significant wildlife health effect of mercury on mammals and reptiles in the Delta, but there is currently very little or no information about it. The characteristics of such linkages are important when prioritizing and funding restoration projects and associated monitoring in the Delta and its tributaries.

  9. Advanced heat receiver conceptual design study

    NASA Technical Reports Server (NTRS)

    Kesseli, James; Saunders, Roger; Batchelder, Gary

    1988-01-01

    Solar Dynamic space power systems are candidate electrical power generating systems for future NASA missions. One of the key components of the solar dynamic power system is the solar receiver/thermal energy storage (TES) subsystem. Receiver development was conducted by NASA in the late 1960's and since then a very limited amount of work has been done in this area. Consequently the state of the art (SOA) receivers designed for the IOC space station are large and massive. The objective of the Advanced Heat Receiver Conceptual Design Study is to conceive and analyze advanced high temperature solar dynamic Brayton and Stirling receivers. The goal is to generate innovative receiver concepts that are half of the mass, smaller, and more efficient than the SOA. It is also necessary that these innovative receivers offer ease of manufacturing, less structural complexity and fewer thermal stress problems. Advanced Brayton and Stirling receiver storage units are proposed and analyzed in this study which can potentially meet these goals.

  10. Advanced turbine systems: Studies and conceptual design

    SciTech Connect

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

    1993-11-01

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

  11. Conceptual models of information processing

    NASA Technical Reports Server (NTRS)

    Stewart, L. J.

    1983-01-01

    The conceptual information processing issues are examined. Human information processing is defined as an active cognitive process that is analogous to a system. It is the flow and transformation of information within a human. The human is viewed as an active information seeker who is constantly receiving, processing, and acting upon the surrounding environmental stimuli. Human information processing models are conceptual representations of cognitive behaviors. Models of information processing are useful in representing the different theoretical positions and in attempting to define the limits and capabilities of human memory. It is concluded that an understanding of conceptual human information processing models and their applications to systems design leads to a better human factors approach.

  12. Model Breaking Points Conceptualized

    ERIC Educational Resources Information Center

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  13. Best of Both Worlds: A Conceptual Model for Integrating an Aging Specialization within an Advanced Generalist MSW Program

    ERIC Educational Resources Information Center

    Dakin, Emily K.; Quijano, Louise M.; Bishop, Pamela S.; Sheafor, Bradford W.

    2015-01-01

    Must a master's of social work (MSW) program's orientation be either advanced generalist or some form of specialist? Or is there the possibility of a hybrid curriculum that provides enough breadth to prepare MSW graduates for a wide range of social work jobs, but that also addresses students' and community agencies' demands for student…

  14. Conceptual Models for Search Engines

    NASA Astrophysics Data System (ADS)

    Hendry, D. G.; Efthimiadis, E. N.

    Search engines have entered popular culture. They touch people in diverse private and public settings and thus heighten the importance of such important social matters as information privacy and control, censorship, and equitable access. To fully benefit from search engines and to participate in debate about their merits, people necessarily appeal to their understandings for how they function. In this chapter we examine the conceptual understandings that people have of search engines by performing a content analysis on the sketches that 200 undergraduate and graduate students drew when asked to draw a sketch of how a search engine works. Analysis of the sketches reveals a diverse range of conceptual approaches, metaphors, representations, and misconceptions. On the whole, the conceptual models articulated by these students are simplistic. However, students with higher levels of academic achievement sketched more complete models. This research calls attention to the importance of improving students' technical knowledge of how search engines work so they can be better equipped to develop and advocate policies for how search engines should be embedded in, and restricted from, various private and public information settings.

  15. toolkit computational mesh conceptual model.

    SciTech Connect

    Baur, David G.; Edwards, Harold Carter; Cochran, William K.; Williams, Alan B.; Sjaardema, Gregory D.

    2010-03-01

    The Sierra Toolkit computational mesh is a software library intended to support massively parallel multi-physics computations on dynamically changing unstructured meshes. This domain of intended use is inherently complex due to distributed memory parallelism, parallel scalability, heterogeneity of physics, heterogeneous discretization of an unstructured mesh, and runtime adaptation of the mesh. Management of this inherent complexity begins with a conceptual analysis and modeling of this domain of intended use; i.e., development of a domain model. The Sierra Toolkit computational mesh software library is designed and implemented based upon this domain model. Software developers using, maintaining, or extending the Sierra Toolkit computational mesh library must be familiar with the concepts/domain model presented in this report.

  16. WRAP 2A advanced conceptual design report comments

    SciTech Connect

    Lamberd, D.L.

    1994-10-04

    This report contains the compilation of the 393 comments that were submitted during the review of the Advanced Conceptual Design Report for the Waste Receiving and Processing Facility Module 2A. The report was prepared by Raytheon Engineers and Constructors, Inc. of Englewood, Colorado for the United States Department of Energy. The review was performed by a variety of organizations identified in the report. The comments were addressed first by the Westinghouse cognizant engineers and then by the Raytheon cognizant engineers, and incorporated into the final issue of the Advanced Conceptual Design Report.

  17. Conceptualizing a Framework for Advanced Placement Statistics Teaching Knowledge

    ERIC Educational Resources Information Center

    Haines, Brenna

    2015-01-01

    The purpose of this article is to sketch a conceptualization of a framework for Advanced Placement (AP) Statistics Teaching Knowledge. Recent research continues to problematize the lack of knowledge and preparation among secondary level statistics teachers. The College Board's AP Statistics course continues to grow and gain popularity, but is a…

  18. A Conceptual Data Model of Datum Systems

    PubMed Central

    McCaleb, Michael R.

    1999-01-01

    A new conceptual data model that addresses the geometric dimensioning and tolerancing concepts of datum systems, datums, datum features, datum targets, and the relationships among these concepts, is presented. Additionally, a portion of a related data model, Part 47 of STEP (ISO 10303-47), is reviewed and a comparison is made between it and the new conceptual data model.

  19. Conceptual and logical level of database modeling

    NASA Astrophysics Data System (ADS)

    Hunka, Frantisek; Matula, Jiri

    2016-06-01

    Conceptual and logical levels form the top most levels of database modeling. Usually, ORM (Object Role Modeling) and ER diagrams are utilized to capture the corresponding schema. The final aim of business process modeling is to store its results in the form of database solution. For this reason, value oriented business process modeling which utilizes ER diagram to express the modeling entities and relationships between them are used. However, ER diagrams form the logical level of database schema. To extend possibilities of different business process modeling methodologies, the conceptual level of database modeling is needed. The paper deals with the REA value modeling approach to business process modeling using ER-diagrams, and derives conceptual model utilizing ORM modeling approach. Conceptual model extends possibilities for value modeling to other business modeling approaches.

  20. A Multivariate Model of Conceptual Change

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Heddy, Benjamin; Bailey, MarLynn; Farley, John

    2016-01-01

    The present study used the Cognitive Reconstruction of Knowledge Model (CRKM) model of conceptual change as a framework for developing and testing how key cognitive, motivational, and emotional variables are linked to conceptual change in physics. This study extends an earlier study developed by Taasoobshirazi and Sinatra ("J Res Sci…

  1. Conceptual Models and Guidelines for Clinical Assessment of Financial Capacity.

    PubMed

    Marson, Daniel

    2016-09-01

    The ability to manage financial affairs is a life skill of critical importance, and neuropsychologists are increasingly asked to assess financial capacity across a variety of settings. Sound clinical assessment of financial capacity requires knowledge and appreciation of applicable clinical conceptual models and principles. However, the literature has presented relatively little conceptual guidance for clinicians concerning financial capacity and its assessment. This article seeks to address this gap. The article presents six clinical models of financial capacity : (1) the early gerontological IADL model of Lawton, (2) the clinical skills model and (3) related cognitive psychological model developed by Marson and colleagues, (4) a financial decision-making model adapting earlier decisional capacity work of Appelbaum and Grisso, (5) a person-centered model of financial decision-making developed by Lichtenberg and colleagues, and (6) a recent model of financial capacity in the real world developed through the Institute of Medicine. Accompanying presentation of the models is discussion of conceptual and practical perspectives they represent for clinician assessment. Based on the models, the article concludes by presenting a series of conceptually oriented guidelines for clinical assessment of financial capacity. In summary, sound assessment of financial capacity requires knowledge and appreciation of clinical conceptual models and principles. Awareness of such models, principles and guidelines will strengthen and advance clinical assessment of financial capacity.

  2. Advanced wind turbine design studies: Advanced conceptual study. Final report

    SciTech Connect

    Hughes, P; Sherwin, R

    1994-08-01

    In conjunction with the US Department of Energy and the National Renewable Energy Laboratory`s Advanced Wind Turbine Program, the Atlantic Orient Corporation developed preliminary designs for the next generation of wind turbines. These 50 kW and 350 kW turbines are based upon the concept of simplicity. By adhering to a design philosophy that emphasizes simplicity, we project that these turbines will produce energy at extremely competitive rates which will unlock the potential of wind energy domestically and internationally. The program consisted of three distinct phases. First, we evaluated the operational history of the Enertech 44 series wind turbines. As a result of this evaluation, we developed, in the second phase, a preliminary design for a new 50 kW turbine for the near-term market. In the third phase, we took a clean-sheet-of-paper approach to designing a 350 kW turbine focused on the mid-1990s utility market that incorporated past experience and advanced technology.

  3. Advanced wind turbine design studies: Advanced conceptual study

    NASA Astrophysics Data System (ADS)

    Hughes, P.; Sherwin, R.

    1994-08-01

    In conjunction with the US Department of Energy and the National Renewable Energy Laboratory's Advanced Wind Turbine Program, the Atlantic Orient Corporation developed preliminary designs for the next generation of wind turbines. These 50 kW and 350 kW turbines are based upon the concept of simplicity. By adhering to a design philosophy that emphasizes simplicity, we project that these turbines will produce energy at extremely competitive rates which will unlock the potential of wind energy domestically and internationally. The program consisted of three distinct phases. First, we evaluated the operational history of the Enertech 44 series wind turbines. As a result of this evaluation, we developed, in the second phase, a preliminary design for a new 50 kW turbine for the near-term market. In the third phase, we took a clean-sheet-of-paper approach to designing a 350 kW turbine focused on the mid-1990s utility market that incorporated past experience and advanced technology.

  4. An Empirical Study of Enterprise Conceptual Modeling

    NASA Astrophysics Data System (ADS)

    Anaby-Tavor, Ateret; Amid, David; Fisher, Amit; Ossher, Harold; Bellamy, Rachel; Callery, Matthew; Desmond, Michael; Krasikov, Sophia; Roth, Tova; Simmonds, Ian; de Vries, Jacqueline

    Business analysts, business architects, and solution consultants use a variety of practices and methods in their quest to understand business. The resulting work products could end up being transitioned into the formal world of software requirement definitions or as recommendations for all kinds of business activities. We describe an empirical study about the nature of these methods, diagrams, and home-grown conceptual models as reflected in real practice at IBM. We identify the models as artifacts of "enterprise conceptual modeling". We study important features of these models, suggest practical classifications, and discuss their usage. Our survey shows that the "enterprise conceptual modeling" arena presents a variety of descriptive models, each used by a relatively small group of colleagues. Together they form a "long tail" that extends from "drawings" on one end to "standards" on the other.

  5. A Conceptual Titan Orbiter Mission Using Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Abelson, Robert D.; Shirley, James H.; Spilker, Thomas R.

    2006-01-01

    This study details a conceptual follow-on Titan orbiter mission that would provide full global topographic coverage. surface imaging, and meteorological characterization of the atmosphere over a nominal 5-year science mission duration. The baseline power requirement is approx.1 kWe at EOM and is driven by a high power radar instrument that would provide 3-dimensional measurements of atmospheric clouds, precipitation, and surface topography. While this power level is moderately higher than that of the Cassini spacecraft. higher efficiency advanced RPSs could potentially reduce the plutonium usage to less than 1/3rd of that used on the Cassini spacecraft. The Titan Orbiter mission is assumed to launch in 2015. It would utilize advanced RPSs to provide all on-board power.

  6. Conceptual frameworks and methods for advancing invasion ecology.

    PubMed

    Heger, Tina; Pahl, Anna T; Botta-Dukát, Zoltan; Gherardi, Francesca; Hoppe, Christina; Hoste, Ivan; Jax, Kurt; Lindström, Leena; Boets, Pieter; Haider, Sylvia; Kollmann, Johannes; Wittmann, Meike J; Jeschke, Jonathan M

    2013-09-01

    Invasion ecology has much advanced since its early beginnings. Nevertheless, explanation, prediction, and management of biological invasions remain difficult. We argue that progress in invasion research can be accelerated by, first, pointing out difficulties this field is currently facing and, second, looking for measures to overcome them. We see basic and applied research in invasion ecology confronted with difficulties arising from (A) societal issues, e.g., disparate perceptions of invasive species; (B) the peculiarity of the invasion process, e.g., its complexity and context dependency; and (C) the scientific methodology, e.g., imprecise hypotheses. To overcome these difficulties, we propose three key measures: (1) a checklist for definitions to encourage explicit definitions; (2) implementation of a hierarchy of hypotheses (HoH), where general hypotheses branch into specific and precisely testable hypotheses; and (3) platforms for improved communication. These measures may significantly increase conceptual clarity and enhance communication, thus advancing invasion ecology.

  7. Conceptual design study: Forest Fire Advanced System Technology (FFAST)

    NASA Technical Reports Server (NTRS)

    Nichols, J. D.; Warren, J. R.

    1986-01-01

    An integrated forest fire detection and mapping system that will be based upon technology available in the 1990s was defined. Uncertainties in emerging and advanced technologies related to the conceptual design were identified and recommended for inclusion as preferred system components. System component technologies identified for an end-to-end system include thermal infrared, linear array detectors, automatic georeferencing and signal processing, geosynchronous satellite communication links, and advanced data integration and display. Potential system configuration options were developed and examined for possible inclusion in the preferred system configuration. The preferred system configuration will provide increased performance and be cost effective over the system currently in use. Forest fire management user requirements and the system component emerging technologies were the basis for the system configuration design. A preferred system configuration was defined that warrants continued refinement and development, examined economic aspects of the current and preferred system, and provided preliminary cost estimates for follow-on system prototype development.

  8. Conceptual and methodological advances in cell-free directed evolution

    PubMed Central

    Dodevski, Igor; Markou, George C.; Sarkar, Casim A.

    2015-01-01

    Although cell-free directed evolution methods have been used to engineer proteins for nearly two decades, selections on more complex phenotypes have largely remained in the domain of cell-based engineering approaches. Here, we review recent conceptual advances that now enable in vitro display of multimeric proteins, integral membrane proteins, and proteins with an expanded amino acid repertoire. Additionally, we discuss methodological improvements that have enhanced the accessibility, efficiency, and robustness of cell-free approaches. Coupling these advances with the in vitro advantages of creating exceptionally large libraries and precisely controlling all experimental conditions, cell-free directed evolution is poised to contribute significantly to our understanding and engineering of more complex protein phenotypes. PMID:26093059

  9. LIGHT SOURCE: Conceptual design of Hefei advanced light source

    NASA Astrophysics Data System (ADS)

    Li, Wei-Min; Wang, Lin; Feng, Guang-Yao; Zhang, Shan-Cai; Wu, Cong-Feng; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, on-momentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm · rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world.

  10. Leading Generative Groups: A Conceptual Model

    ERIC Educational Resources Information Center

    London, Manuel; Sobel-Lojeski, Karen A.; Reilly, Richard R.

    2012-01-01

    This article presents a conceptual model of leadership in generative groups. Generative groups have diverse team members who are expected to develop innovative solutions to complex, unstructured problems. The challenge for leaders of generative groups is to balance (a) establishing shared goals with recognizing members' vested interests, (b)…

  11. Multiple Mentor Model: A Conceptual Framework.

    ERIC Educational Resources Information Center

    Burlew, Larry D.

    1991-01-01

    Focuses on developing a conceptual framework for the mentoring process. The model is based on the premise that mentoring is not a single event in the life of a worker but rather several events with several different levels of mentoring. (Author)

  12. Conceptual Models of Frontal Cyclones.

    ERIC Educational Resources Information Center

    Eagleman, Joe R.

    1981-01-01

    This discussion of weather models uses maps to illustrate the differences among three types of frontal cyclones (long wave, short wave, and troughs). Awareness of these cyclones can provide clues to atmospheric conditions which can lead toward accurate weather forecasting. (AM)

  13. A conceptual model for megaprogramming

    NASA Technical Reports Server (NTRS)

    Tracz, Will

    1990-01-01

    Megaprogramming is component-based software engineering and life-cycle management. Magaprogramming and its relationship to other research initiatives (common prototyping system/common prototyping language, domain specific software architectures, and software understanding) are analyzed. The desirable attributes of megaprogramming software components are identified and a software development model and resulting prototype megaprogramming system (library interconnection language extended by annotated Ada) are described.

  14. The conceptualization model problem—surprise

    NASA Astrophysics Data System (ADS)

    Bredehoeft, John

    2005-03-01

    The foundation of model analysis is the conceptual model. Surprise is defined as new data that renders the prevailing conceptual model invalid; as defined here it represents a paradigm shift. Limited empirical data indicate that surprises occur in 20-30% of model analyses. These data suggest that groundwater analysts have difficulty selecting the appropriate conceptual model. There is no ready remedy to the conceptual model problem other than (1) to collect as much data as is feasible, using all applicable methods—a complementary data collection methodology can lead to new information that changes the prevailing conceptual model, and (2) for the analyst to remain open to the fact that the conceptual model can change dramatically as more information is collected. In the final analysis, the hydrogeologist makes a subjective decision on the appropriate conceptual model. The conceptualization problem does not render models unusable. The problem introduces an uncertainty that often is not widely recognized. Conceptual model uncertainty is exacerbated in making long-term predictions of system performance. C'est le modèle conceptuel qui se trouve à base d'une analyse sur un modèle. On considère comme une surprise lorsque le modèle est invalidé par des données nouvelles; dans les termes définis ici la surprise est équivalente à un change de paradigme. Des données empiriques limitées indiquent que les surprises apparaissent dans 20 à 30% des analyses effectuées sur les modèles. Ces données suggèrent que l'analyse des eaux souterraines présente des difficultés lorsqu'il s'agit de choisir le modèle conceptuel approprié. Il n'existe pas un autre remède au problème du modèle conceptuel que: (1) rassembler autant des données que possible en utilisant toutes les méthodes applicables—la méthode des données complémentaires peut conduire aux nouvelles informations qui vont changer le modèle conceptuel, et (2) l'analyste doit rester ouvert au fait

  15. Conceptual design study of advanced acoustic-composite nacelles

    NASA Technical Reports Server (NTRS)

    Nordstrom, K. E.; Marsh, A. H.; Sargisson, D. F.

    1975-01-01

    Conceptual studies were conducted to assess the impact of incorporating advanced technologies in the nacelles of a current wide-bodied transport and an advanced technology transport. The improvement possible in the areas of fuel consumption, flyover noise levels, airplane weight, manufacturing costs, and airplane operating cost were evaluated for short and long-duct nacelles. Use of composite structures for acoustic duct linings in the fan inlet and exhaust ducts was considered as well as for other nacelle components. For the wide-bodied transport, the use of a long-duct nacelle with an internal mixer nozzle in the primary exhaust showed significant improvement in installed specific fuel consumption and airplane direct operating costs compared to the current short-duct nacelle. The long-duct mixed-flow nacelle is expected to achieve significant reductions in jet noise during takeoff and in turbo-machinery noise during landing approach. Recommendations were made of the technology development needed to achieve the potential fuel conservation and noise reduction benefits.

  16. A dynamic conceptual model of care planning.

    PubMed

    Elf, Marie; Poutilova, Maria; Ohrn, Kerstin

    2007-12-01

    This article presents a conceptual model of the care planning process developed to identify the hypothetical links between structural, process and outcome factors important to the quality of the process. Based on existing literature, it was hypothesized that a thorough assessment of patients' health needs is an important prerequisite when making a rigorous diagnosis and preparing plans for various care interventions. Other important variables that are assumed to influence the quality of the process are the care culture and professional knowledge. The conceptual model was developed as a system dynamics causal loop diagram as a first essential step towards a computed model. System dynamics offers the potential to describe processes in a nonlinear, dynamic way and is suitable for exploring, comprehending, learning and communicating complex ideas about care processes.

  17. Uncertainty and the Conceptual Site Model

    NASA Astrophysics Data System (ADS)

    Price, V.; Nicholson, T. J.

    2007-12-01

    Our focus is on uncertainties in the underlying conceptual framework upon which all subsequent steps in numerical and/or analytical modeling efforts depend. Experienced environmental modelers recognize the value of selecting an optimal conceptual model from several competing site models, but usually do not formally explore possible alternative models, in part due to incomplete or missing site data, as well as relevant regional data for establishing boundary conditions. The value in and approach for developing alternative conceptual site models (CSM) is demonstrated by analysis of case histories. These studies are based on reported flow or transport modeling in which alternative site models are formulated using data that were not available to, or not used by, the original modelers. An important concept inherent to model abstraction of these alternative conceptual models is that it is "Far better an approximate answer to the right question, which is often vague, than the exact answer to the wrong question, which can always be made precise." (Tukey, 1962) The case histories discussed here illustrate the value of formulating alternative models and evaluating them using site-specific data: (1) Charleston Naval Site where seismic characterization data allowed significant revision of the CSM and subsequent contaminant transport modeling; (2) Hanford 300-Area where surface- and ground-water interactions affecting the unsaturated zone suggested an alternative component to the site model; (3) Savannah River C-Area where a characterization report for a waste site within the modeled area was not available to the modelers, but provided significant new information requiring changes to the underlying geologic and hydrogeologic CSM's used; (4) Amargosa Desert Research Site (ADRS) where re-interpretation of resistivity sounding data and water-level data suggested an alternative geologic model. Simple 2-D spreadsheet modeling of the ADRS with the revised CSM provided an improved

  18. Critical conceptualism in environmental modeling and prediction.

    PubMed

    Christakos, G

    2003-10-15

    Many important problems in environmental science and engineering are of a conceptual nature. Research and development, however, often becomes so preoccupied with technical issues, which are themselves fascinating, that it neglects essential methodological elements of conceptual reasoning and theoretical inquiry. This work suggests that valuable insight into environmental modeling can be gained by means of critical conceptualism which focuses on the software of human reason and, in practical terms, leads to a powerful methodological framework of space-time modeling and prediction. A knowledge synthesis system develops the rational means for the epistemic integration of various physical knowledge bases relevant to the natural system of interest in order to obtain a realistic representation of the system, provide a rigorous assessment of the uncertainty sources, generate meaningful predictions of environmental processes in space-time, and produce science-based decisions. No restriction is imposed on the shape of the distribution model or the form of the predictor (non-Gaussian distributions, multiple-point statistics, and nonlinear models are automatically incorporated). The scientific reasoning structure underlying knowledge synthesis involves teleologic criteria and stochastic logic principles which have important advantages over the reasoning method of conventional space-time techniques. Insight is gained in terms of real world applications, including the following: the study of global ozone patterns in the atmosphere using data sets generated by instruments on board the Nimbus 7 satellite and secondary information in terms of total ozone-tropopause pressure models; the mapping of arsenic concentrations in the Bangladesh drinking water by assimilating hard and soft data from an extensive network of monitoring wells; and the dynamic imaging of probability distributions of pollutants across the Kalamazoo river.

  19. Social Determinants and Health Behaviors: Conceptual Frames and Empirical Advances.

    PubMed

    Short, Susan E; Mollborn, Stefanie

    2015-10-01

    Health behaviors shape health and well-being in individuals and populations. Drawing on recent research, we review applications of the widely applied "social determinants" approach to health behaviors. This approach shifts the lens from individual attribution and responsibility to societal organization and the myriad institutions, structures, inequalities, and ideologies undergirding health behaviors. Recent scholarship integrates a social determinants perspective with biosocial approaches to health behavior dynamics. Empirical advances model feedback among social, psychological and biological factors. Health behaviors are increasingly recognized as multidimensional and embedded in health lifestyles, varying over the life course and across place and reflecting dialectic between structure and agency that necessitates situating individuals in context. Advances in measuring and modeling health behaviors promise to enhance representations of this complexity.

  20. Social Determinants and Health Behaviors: Conceptual Frames and Empirical Advances

    PubMed Central

    Short, Susan E.; Mollborn, Stefanie

    2015-01-01

    Health behaviors shape health and well-being in individuals and populations. Drawing on recent research, we review applications of the widely applied “social determinants” approach to health behaviors. This approach shifts the lens from individual attribution and responsibility to societal organization and the myriad institutions, structures, inequalities, and ideologies undergirding health behaviors. Recent scholarship integrates a social determinants perspective with biosocial approaches to health behavior dynamics. Empirical advances model feedback among social, psychological and biological factors. Health behaviors are increasingly recognized as multidimensional and embedded in health lifestyles, varying over the life course and across place and reflecting dialectic between structure and agency that necessitates situating individuals in context. Advances in measuring and modeling health behaviors promise to enhance representations of this complexity. PMID:26213711

  1. Achievements and Problems of Conceptual Modelling

    NASA Astrophysics Data System (ADS)

    Thalheim, Bernhard

    Database and information systems technology has substantially changed. Nowadays, content management systems, (information-intensive) web services, collaborating systems, internet databases, OLAP databases etc. have become buzzwords. At the same time, object-relational technology has gained the maturity for being widely applied. Conceptual modelling has not (yet) covered all these novel topics. It has been concentrated for more than two decades around specification of structures. Meanwhile, functionality, interactivity and distribution must be included into conceptual modelling of information systems. Also, some of the open problems that have been already discussed in 1987 [15, 16] still remain to be open. At the same time, novel models such as object-relational models or XML-based models have been developed. They did not overcome all the problems but have been sharpening and extending the variety of open problems. The open problem presented are given for classical areas of database research, i.e., structuring and functionality. The entire are of distribution and interaction is currently an area of very intensive research.

  2. A Structural Equation Model of Conceptual Change in Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Sinatra, Gale M.

    2011-01-01

    A model of conceptual change in physics was tested on introductory-level, college physics students. Structural equation modeling was used to test hypothesized relationships among variables linked to conceptual change in physics including an approach goal orientation, need for cognition, motivation, and course grade. Conceptual change in physics…

  3. Conceptual Frameworks in the Doctoral Research Process: A Pedagogical Model

    ERIC Educational Resources Information Center

    Berman, Jeanette; Smyth, Robyn

    2015-01-01

    This paper contributes to consideration of the role of conceptual frameworks in the doctoral research process. Through reflection on the two authors' own conceptual frameworks for their doctoral studies, a pedagogical model has been developed. The model posits the development of a conceptual framework as a core element of the doctoral…

  4. A Conceptual Model of Referee Efficacy

    PubMed Central

    Guillén, Félix; Feltz, Deborah L.

    2010-01-01

    This paper presents a conceptual model of referee efficacy, defines the concept, proposes sources of referee specific efficacy information, and suggests consequences of having high or low referee efficacy. Referee efficacy is defined as the extent to which referees believe they have the capacity to perform successfully in their job. Referee efficacy beliefs are hypothesized to be influenced by mastery experiences, referee knowledge/education, support from significant others, physical/mental preparedness, environmental comfort, and perceived anxiety. In turn, referee efficacy beliefs are hypothesized to influence referee performance, referee stress, athlete rule violations, athlete satisfaction, and co-referee satisfaction. PMID:21713174

  5. Propulsion System Models for Rotorcraft Conceptual Design

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne

    2014-01-01

    The conceptual design code NDARC (NASA Design and Analysis of Rotorcraft) was initially implemented to model conventional rotorcraft propulsion systems, consisting of turboshaft engines burning jet fuel, connected to one or more rotors through a mechanical transmission. The NDARC propulsion system representation has been extended to cover additional propulsion concepts, including electric motors and generators, rotor reaction drive, turbojet and turbofan engines, fuel cells and solar cells, batteries, and fuel (energy) used without weight change. The paper describes these propulsion system components, the architecture of their implementation in NDARC, and the form of the models for performance and weight. Requirements are defined for improved performance and weight models of the new propulsion system components. With these new propulsion models, NDARC can be used to develop environmentally-friendly rotorcraft designs.

  6. CONCEPTUAL MODELS FOR THE LASSEN HYDROTHERMAL SYSTEM.

    USGS Publications Warehouse

    Ingebritsen, S.E.; Sorey, M.L.

    1987-01-01

    The Lassen hydrothermal system, like a number of other systems in regions of moderate to great topographic relief, includes steam-heated features at higher elevations and high-chloride springs at lower elevations, connected to and fed by a single circulation system at depth. Two conceptual models for such systems are presented. They are similar in several ways: however, there are basic differences in terms of the nature and extent of vapor-dominated conditions beneath the steam-heated features. For some Lassen-like systems, these differences could have environmental and economic implications. Available data do not make it possible to establish a single preferred model for the Lassen system, and the actual system is complex enough that both models may apply to different parts of the system.

  7. Detecting hydrological changes through conceptual model

    NASA Astrophysics Data System (ADS)

    Viola, Francesco; Caracciolo, Domenico; Pumo, Dario; Francipane, Antonio; Valerio Noto, Leonardo

    2015-04-01

    Natural changes and human modifications in hydrological systems coevolve and interact in a coupled and interlinked way. If, on one hand, climatic changes are stochastic, non-steady, and affect the hydrological systems, on the other hand, human-induced changes due to over-exploitation of soils and water resources modifies the natural landscape, water fluxes and its partitioning. Indeed, the traditional assumption of static systems in hydrological analysis, which has been adopted for long time, fails whenever transient climatic conditions and/or land use changes occur. Time series analysis is a way to explore environmental changes together with societal changes; unfortunately, the not distinguishability between causes restrict the scope of this method. In order to overcome this limitation, it is possible to couple time series analysis with an opportune hydrological model, such as a conceptual hydrological model, which offers a schematization of complex dynamics acting within a basin. Assuming that model parameters represent morphological basin characteristics and that calibration is a way to detect hydrological signature at a specific moment, it is possible to argue that calibrating the model over different time windows could be a method for detecting potential hydrological changes. In order to test the capabilities of a conceptual model in detecting hydrological changes, this work presents different "in silico" experiments. A synthetic-basin is forced with an ensemble of possible future scenarios generated with a stochastic weather generator able to simulate steady and non-steady climatic conditions. The experiments refer to Mediterranean climate, which is characterized by marked seasonality, and consider the outcomes of the IPCC 5th report for describing climate evolution in the next century. In particular, in order to generate future climate change scenarios, a stochastic downscaling in space and time is carried out using realizations of an ensemble of General

  8. A conceptual, distributed snow redistribution model

    NASA Astrophysics Data System (ADS)

    Frey, S.; Holzmann, H.

    2015-01-01

    When applying conceptual hydrological models using a temperature index approach for snowmelt to high alpine areas often accumulation of snow during several years can be observed. Some of the reasons why these "snow towers" do not exist in nature are vertical and lateral transport processes. While snow transport models have been developed using grid cell sizes of tens to hundreds of square meters and have been applied in several catchments, no model exists using coarser cell sizes of one km2. In this paper we present an approach that uses only gravity and snow density as a proxy for the age of the snow cover and land-use information to redistribute snow in the catchment of Ötztaler Ache, Austria. This transport model is implemented in the distributed rainfall-runoff model COSERO and a comparison between the standard model without using snow transport and the updated version is done using runoff and MODIS data for model validation. While the signal of snow redistribution can hardly be seen in the binary classification compared with MODIS, snow accumulation over several years can be prevented. In a seven year period the classic model would lead to snow accumulation of approximately 2900 mm SWE in high elevated regions whereas the updated version of the model does not show accumulation and does also predict discharge more precisely leading to a Kling-Gupta-Efficiency of 0.93 instead of 0.9.

  9. Multimorbidity: conceptual basis, epidemiological models and measurement challenges.

    PubMed

    Fernández-Niño, Julián Alfredo; Bustos-Vázquez, Eduardo

    2016-06-03

    The growing number of patients with complex clinical profiles related to chronic diseases has contributed to the increasingly widespread use of the term 'multimorbidity'. A suitable measurement of this condition is essential to epidemiological studies considering that it represents a challenge for the clinical management of patients as well as for health systems and epidemiological investigations. In this context, the present essay reviews the conceptual proposals behind the measurement of multimorbidity including the epidemiological and methodological challenges it involves. We discuss classical definitions of comorbidity, how they differ from the concept of multimorbidity, and their roles in epidemiological studies. The various conceptual models that contribute to the operational definitions and strategies to measure this variable are also presented. The discussion enabled us to identify a significant gap between the modern conceptual development of multimorbidity and the operational definitions. This gap exists despite the theoretical developments that have occurred in the classical concept of comorbidity to arrive to the modern and multidimensional conception of multimorbidty. Measurement strategies, however, have not kept pace with this advance. Therefore, new methodological proposals need to be developed in order to obtain information regarding the actual impact on individuals' health and its implications for public health.

  10. Conceptual models as hypotheses in monitoring urban landscapes.

    PubMed

    Lookingbill, Todd R; Gardner, Robert H; Townsend, Philip A; Carter, Shawn L

    2007-08-01

    Many problems and challenges of ecosystem management currently are driven by the rapid pace and spatial extent of landscape change. Parks and reserves within areas of high human population density are especially challenged to meet the recreational needs of local populations and to preserve valued environmental resources. The complex problem of managing multiple objectives and multiple resources requires an enormous quantity of information, and conceptual models have been proposed as tools for organizing and interpreting this information. Academics generally prefer a bottom-up approach to model construction that emphasizes ecologic theory and process, whereas managers often use a top-down approach that takes advantage of existing information to address more pragmatic objectives. The authors propose a formal process for developing, applying, and testing conceptual models to be used in landscape monitoring that reconciles these seemingly opposing perspectives. The four-step process embraces the role of hypothesis testing in the development of models and evaluation of their utility. An example application of the process to a network of national parks in and around Washington, DC illustrates the ability of the approach to systematically identify monitoring data that would both advance ecologic theory and inform management decisions.

  11. Equivalent plate modeling for conceptual design of aircraft wing structures

    NASA Technical Reports Server (NTRS)

    Giles, Gary L.

    1995-01-01

    This paper describes an analysis method that generates conceptual-level design data for aircraft wing structures. A key requirement is that this data must be produced in a timely manner so that is can be used effectively by multidisciplinary synthesis codes for performing systems studies. Such a capability is being developed by enhancing an equivalent plate structural analysis computer code to provide a more comprehensive, robust and user-friendly analysis tool. The paper focuses on recent enhancements to the Equivalent Laminated Plate Solution (ELAPS) analysis code that significantly expands the modeling capability and improves the accuracy of results. Modeling additions include use of out-of-plane plate segments for representing winglets and advanced wing concepts such as C-wings along with a new capability for modeling the internal rib and spar structure. The accuracy of calculated results is improved by including transverse shear effects in the formulation and by using multiple sets of assumed displacement functions in the analysis. Typical results are presented to demonstrate these new features. Example configurations include a C-wing transport aircraft, a representative fighter wing and a blended-wing-body transport. These applications are intended to demonstrate and quantify the benefits of using equivalent plate modeling of wing structures during conceptual design.

  12. The Aircraft Availability Model: Conceptual Framework and Mathematics

    DTIC Science & Technology

    1983-06-01

    THE AIRCRAFT AVAILABILITY MODEL: CONCEPTUAL FRAMEWORK AND MATHEMATICS June 1983 T. J. O’Malley Prepared pursuant to Department of Defense Contract No...OF REPORT & PERIOD COVERED The Aircraft Availability Model: Model Documentation Conceptual Framework and Mathematics 6. PERFORMING ORG. REPORT NUMBER

  13. NADM Conceptual Model 1.0 -- A Conceptual Model for Geologic Map Information

    USGS Publications Warehouse

    ,

    2004-01-01

    Executive Summary -- The NADM Data Model Design Team was established in 1999 by the North American Geologic Map Data Model Steering Committee (NADMSC) with the purpose of drafting a geologic map data model for consideration as a standard for developing interoperable geologic map-centered databases by state, provincial, and federal geological surveys. The model is designed to be a technology-neutral conceptual model that can form the basis for a web-based interchange format using evolving information technology (e.g., XML, RDF, OWL), and guide implementation of geoscience databases in a common conceptual framework. The intended purpose is to allow geologic information sharing between geologic map data providers and users, independent of local information system implementation. The model emphasizes geoscience concepts and relationships related to information presented on geologic maps. Design has been guided by an informal requirements analysis, documentation of existing databases, technology developments, and other standardization efforts in the geoscience and computer-science communities. A key aspect of the model is the notion that representation of the conceptual framework (ontology) that underlies geologic map data must be part of the model, because this framework changes with time and understanding, and varies between information providers. The top level of the model distinguishes geologic concepts, geologic representation concepts, and metadata. The geologic representation part of the model provides a framework for representing the ontology that underlies geologic map data through a controlled vocabulary, and for establishing the relationships between this vocabulary and a geologic map visualization or portrayal. Top-level geologic classes in the model are Earth material (substance), geologic unit (parts of the Earth), geologic age, geologic structure, fossil, geologic process, geologic relation, and geologic event.

  14. A conceptual, distributed snow redistribution model

    NASA Astrophysics Data System (ADS)

    Frey, S.; Holzmann, H.

    2015-11-01

    When applying conceptual hydrological models using a temperature index approach for snowmelt to high alpine areas often accumulation of snow during several years can be observed. Some of the reasons why these "snow towers" do not exist in nature are vertical and lateral transport processes. While snow transport models have been developed using grid cell sizes of tens to hundreds of square metres and have been applied in several catchments, no model exists using coarser cell sizes of 1 km2, which is a common resolution for meso- and large-scale hydrologic modelling (hundreds to thousands of square kilometres). In this paper we present an approach that uses only gravity and snow density as a proxy for the age of the snow cover and land-use information to redistribute snow in alpine basins. The results are based on the hydrological modelling of the Austrian Inn Basin in Tyrol, Austria, more specifically the Ötztaler Ache catchment, but the findings hold for other tributaries of the river Inn. This transport model is implemented in the distributed rainfall-runoff model COSERO (Continuous Semi-distributed Runoff). The results of both model concepts with and without consideration of lateral snow redistribution are compared against observed discharge and snow-covered areas derived from MODIS satellite images. By means of the snow redistribution concept, snow accumulation over several years can be prevented and the snow depletion curve compared with MODIS (Moderate Resolution Imaging Spectroradiometer) data could be improved, too. In a 7-year period the standard model would lead to snow accumulation of approximately 2900 mm SWE (snow water equivalent) in high elevated regions whereas the updated version of the model does not show accumulation and does also predict discharge with more accuracy leading to a Kling-Gupta efficiency of 0.93 instead of 0.9. A further improvement can be shown in the comparison of MODIS snow cover data and the calculated depletion curve, where

  15. Showing Automatically Generated Students' Conceptual Models to Students and Teachers

    ERIC Educational Resources Information Center

    Perez-Marin, Diana; Pascual-Nieto, Ismael

    2010-01-01

    A student conceptual model can be defined as a set of interconnected concepts associated with an estimation value that indicates how well these concepts are used by the students. It can model just one student or a group of students, and can be represented as a concept map, conceptual diagram or one of several other knowledge representation…

  16. Conceptual Model Learning Objects and Design Recommendations for Small Screens

    ERIC Educational Resources Information Center

    Churchill, Daniel

    2011-01-01

    This article presents recommendations for the design of conceptual models for applications via handheld devices such as personal digital assistants and some mobile phones. The recommendations were developed over a number of years through experience that involves design of conceptual models, and applications of these multimedia representations with…

  17. A conceptual model of people's vulnerability to floods

    NASA Astrophysics Data System (ADS)

    Milanesi, Luca; Pilotti, Marco; Ranzi, Roberto

    2015-01-01

    Hydraulic risk maps provide the baseline for land use and emergency planning. Accordingly, they should convey clear information on the potential physical implications of the different hazards to the stakeholders. This paper presents a vulnerability criterion focused on human stability in a flow specifically devised for rapidly evolving floods where life, before than economic values, might be threatened. The human body is conceptualized as a set of cylinders and its stability to slipping and toppling is assessed by forces and moments equilibrium. Moreover, a depth threshold to consider drowning is assumed. In order to widen its scope of application, the model takes the destabilizing effect of local slope (so far disregarded in the literature) and fluid density into account. The resulting vulnerability classification could be naturally subdivided in three levels (low, medium, and high) that are limited by two stability curves for children and adults, respectively. In comparison with the most advanced literature conceptual approaches, the proposed model is weakly parameterized and the computed thresholds fit better the available experimental data sets. A code that implements the proposed algorithm is provided.

  18. Advanced conceptual design report. Phase II. Liquid effluent treatment and disposal Project W-252

    SciTech Connect

    1995-01-31

    This Advanced Conceptual Design Report (ACDR) provides a documented review and analysis of the Conceptual Design Report (CDR), WHC-SD-W252-CDR-001, June 30, 1993. The ACDR provides further design evaluation of the major design approaches and uncertainties identified in the original CDR. The ACDR will provide a firmer basis for the both the design approach and the associated planning for the performance of the Definitive Design phase of the project.

  19. Advanced Turbine Systems (ATS) program conceptual design and product development

    SciTech Connect

    1996-08-31

    Achieving the Advanced Turbine Systems (ATS) goals of 60% efficiency, single-digit NO{sub x}, and 10% electric power cost reduction imposes competing characteristics on the gas turbine system. Two basic technical issues arise from this. The turbine inlet temperature of the gas turbine must increase to achieve both efficiency and cost goals. However, higher temperatures move in the direction of increased NO{sub x} emission. Improved coatings and materials technologies along with creative combustor design can result in solutions to achieve the ultimate goal. GE`s view of the market, in conjunction with the industrial and utility objectives, requires the development of Advanced Gas Turbine Systems which encompass two potential products: a new aeroderivative combined-cycle system for the industrial market, and a combined-cycle system for the utility sector that is based on an advanced frame machine. The GE Advanced Gas Turbine Development program is focused on two specific products: (1) a 70 MW class industrial gas turbine based on the GE90 core technology utilizing an innovative air cooling methodology; (2) a 200 MW class utility gas turbine based on an advanced Ge heavy-duty machine utilizing advanced cooling and enhancement in component efficiency. Both of these activities required the identification and resolution of technical issues critical to achieving ATS goals. The emphasis for the industrial ATS was placed upon innovative cycle design and low emission combustion. The emphasis for the utility ATS was placed on developing a technology base for advanced turbine cooling, while utilizing demonstrated and planned improvements in low emission combustion. Significant overlap in the development programs will allow common technologies to be applied to both products. GE Power Systems is solely responsible for offering GE products for the industrial and utility markets.

  20. Conceptual model for heart failure disease management.

    PubMed

    Andrikopoulou, Efstathia; Abbate, Kariann; Whellan, David J

    2014-03-01

    The objective of this review is to propose a conceptual model for heart failure (HF) disease management (HFDM) and to define the components of an efficient HFDM plan in reference to this model. Articles that evaluated 1 or more of the following aspects of HFDM were reviewed: (1) outpatient clinic follow-up; (2) self-care interventions to enhance patient skills; and (3) remote evaluation of worsening HF either using structured telephone support (STS) or by monitoring device data (telemonitoring). The success of programs in reducing readmissions and mortality were mixed. Outpatient follow-up programs generally resulted in improved outcomes, including decreased readmissions. Based on 1 meta-analysis, specialty clinics improved outcomes and nonspecialty clinics did not. Results from self-care programs were inconsistent and might have been affected by patient cognitive status and educational level, and intervention intensity. Telemonitoring, despite initially promising meta-analyses demonstrating a decrease in the number and duration of HF-related readmissions and all-cause mortality rates at follow-up, has not been shown in randomized trials to consistently reduce readmissions or mortality. However, evidence from device monitoring trials in particular might have been influenced by technology and design issues that might be rectified in future trials. Results from the literature suggest that the ideal HFDM plan would include outpatient follow-up at an HF specialty clinic and continuous education to improve patient self-care. The end result of this plan would lead to better understanding on the part of the patient and improved patient ability to recognize and respond to signs of decompensation.

  1. ADVANCED TURBINE SYSTEM CONCEPTUAL DESIGN AND PRODUCT DEVELOPMENT - Final Report

    SciTech Connect

    Albrecht H. Mayer

    2000-07-15

    Asea Brown Boveri (ABB) has completed its technology based program. The results developed under Work Breakdown Structure (WBS) 8, concentrated on technology development and demonstration have been partially implemented in newer turbine designs. A significant improvement in heat rate and power output has been demonstrated. ABB will use the knowledge gained to further improve the efficiency of its Advanced Cycle System, which has been developed and introduced into the marked out side ABB's Advanced Turbine System (ATS) activities. The technology will lead to a power plant design that meets the ATS performance goals of over 60% plant efficiency, decreased electricity costs to consumers and lowest emissions.

  2. Conceptual and Numerical Models for UZ Flow and Transport

    SciTech Connect

    H. Liu

    2000-03-03

    The purpose of this Analysis/Model Report (AMR) is to document the conceptual and numerical models used for modeling of unsaturated zone (UZ) fluid (water and air) flow and solute transport processes. This is in accordance with ''AMR Development Plan for U0030 Conceptual and Numerical Models for Unsaturated Zone (UZ) Flow and Transport Processes, Rev 00''. The conceptual and numerical modeling approaches described in this AMR are used for models of UZ flow and transport in fractured, unsaturated rock under ambient and thermal conditions, which are documented in separate AMRs. This AMR supports the UZ Flow and Transport Process Model Report (PMR), the Near Field Environment PMR, and the following models: Calibrated Properties Model; UZ Flow Models and Submodels; Mountain-Scale Coupled Processes Model; Thermal-Hydrologic-Chemical (THC) Seepage Model; Drift Scale Test (DST) THC Model; Seepage Model for Performance Assessment (PA); and UZ Radionuclide Transport Models.

  3. Thoughts about conceptual models, theories, and quality improvement projects.

    PubMed

    Fawcett, Jacqueline

    2014-10-01

    This essay focuses on how a conceptual model of nursing can be the basis for identification of the phenomenon of interest for a quality improvement project and how a theory of quality improvement or a theory of change is the methodological guide for the project. An explanation and examples of conceptual-theoretical-empirical structures for quality improvement projects are given.

  4. Using Conceptual Change Theories to Model Position Concepts in Astronomy

    ERIC Educational Resources Information Center

    Yang, Chih-Chiang; Hung, Jeng-Fung

    2012-01-01

    The roles of conceptual change and model building in science education are very important and have a profound and wide effect on teaching science. This study examines the change in children's position concepts after instruction, based on different conceptual change theories. Three classes were chosen and divided into three groups, including a…

  5. Model of Conceptual Change for INQPRO: A Bayesian Network Approach

    ERIC Educational Resources Information Center

    Ting, Choo-Yee; Sam, Yok-Cheng; Wong, Chee-Onn

    2013-01-01

    Constructing a computational model of conceptual change for a computer-based scientific inquiry learning environment is difficult due to two challenges: (i) externalizing the variables of conceptual change and its related variables is difficult. In addition, defining the causal dependencies among the variables is also not trivial. Such difficulty…

  6. 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.

  7. Conceptualizing prognostic awareness in advanced cancer: A systematic review

    PubMed Central

    Applebaum, Allison J; Kolva, Elissa A; Kulikowski, Julia R; Jacobs, Jordana D; DeRosa, Antonio; Lichtenthal, Wendy G; Olden, Megan E; Rosenfeld, Barry; Breitbart, William

    2015-01-01

    This systematic review synthesizes the complex literature on prognostic awareness in cancer. A total of 37 studies examining cancer patients’ understanding of their prognosis were included. Prognostic awareness definitions and assessment methods were inconsistent across studies. A surprisingly high percentage of patients (up to 75%) were unaware of their poor prognosis, and in several studies, even their cancer diagnosis (up to 96%), particularly in studies conducted outside of North America. This review highlights surprisingly low rates of prognostic awareness in patients with advanced cancer as well as discrepancies in prognostic awareness assessment, suggesting the need for empirically validated measures of prognostic awareness. PMID:24157936

  8. A conceptual venus rover mission using advanced radioisotope power system

    NASA Technical Reports Server (NTRS)

    Evans, Michael; Shirley, James H.; Abelson, Robert Dean

    2006-01-01

    The primary goal of this study is to examine the feasibility of using the novel Advanced RPS-driven Stirling thermoacoustic system to enable extended science operations in the extremely hostile surface environment of Venus. The mission concept entails landing a rover onto the Venus surface, conducting science measurements in different areas on the surface, and returning the science data to Earth. The study focused on developing a rover design to satisfy the science goals with the capability to operate for 60 days. This mission life influences several design parameters, including Earth elevation angle and the maximum communications range to Earth.

  9. Conceptualizing prognostic awareness in advanced cancer: a systematic review.

    PubMed

    Applebaum, Allison J; Kolva, Elissa A; Kulikowski, Julia R; Jacobs, Jordana D; DeRosa, Antonio; Lichtenthal, Wendy G; Olden, Megan E; Rosenfeld, Barry; Breitbart, William

    2014-09-01

    This systematic review synthesizes the complex literature on prognostic awareness in cancer. A total of 37 studies examining cancer patients' understanding of their prognosis were included. Prognostic awareness definitions and assessment methods were inconsistent across studies. A surprisingly high percentage of patients (up to 75%) were unaware of their poor prognosis, and in several studies, even their cancer diagnosis (up to 96%), particularly in studies conducted outside of North America. This review highlights surprisingly low rates of prognostic awareness in patients with advanced cancer as well as discrepancies in prognostic awareness assessment, suggesting the need for empirically validated measures of prognostic awareness.

  10. The Effect of Conceptual Advancement in Jazz Music Selections and Jazz Experience on Musicians' Aesthetic Response

    ERIC Educational Resources Information Center

    Coggiola, John C.

    2004-01-01

    This study is an investigation of what musicians consider to be their aesthetic experience with jazz music selections that vary in level of conceptual advancement (melodic complexity during improvised solos). Music major participants (N = 128) were assigned to either the jazz musician (n = 64) or nonjazz musician (n = 64) group. Data were gathered…

  11. A Conceptual Venus Rover Mission Using Advanced Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Evans, Michael; Shirley, James H.; Abelson, Robert Dean

    2006-01-01

    This concept study demonstrates that a long lived Venus rover mission could be enabled by a novel application of advanced RPS technology. General Purpose Heat Source (GPHS) modules would be employed to drive an advanced thermoacoustic Stirling engine, pulse tube cooler and linear alternator that provides electric power and cooling for the rover. The Thermoacoustic Stirling Heat Engine (TASHE) is a system for converting high-temperature heat into acoustic power which then drives linear alternators and a pulse tube cooler to provide both electric power and coolin6g for the rover. A small design team examined this mission concept focusing on the feasibility of using the TASHE system in this hostile environment. A rover design is described that would provide a mobile platform for science measurements on the Venus surface for 60 days, with the potential of operating well beyond that. A suite of science instruments is described that collects data on atmospheric and surface composition, surface stratigraphy, and subsurface structure. An Earth-Venus-Venus trajectory would be used to deliver the rover to a low entry angle allowing an inflated ballute to provide a low deceleration and low heat descent to the surface. All rover systems would be housed in a pressure vessel in vacuum with the internal temperature maintained by the TASHE at under 50 °C.

  12. An Integrative-Interactive Conceptual Model for Curriculum Development.

    ERIC Educational Resources Information Center

    Al-Ibrahim, Abdul Rahman H.

    1982-01-01

    The Integrative-Interactive Conceptual Model for Curriculum Development calls for curriculum reform and innovation to be cybernetic so that all aspects of curriculum planning get adequate attention. (CJ)

  13. Conceptual design of the advanced marine reactor MRX

    NASA Astrophysics Data System (ADS)

    1991-02-01

    Design studies on the advanced marine reactors have been done continuously since 1983 at the Japan Atomic Energy Research Institute (JAERI) in order to develop attractive marine reactors for the next generation. At present, two marine reactor concepts are being formulated. One is 100 MWt MRX (Marine Reactor X) for an icebreaker and the other is 300 kWe DRX (Deep-sea Reactor X) for a deep-sea research vessel. They are characterized by an integral type pressurized water reactor (PWR) built-in type control rod drive mechanisms, a water-filled container and a passive decay heat removal system, which realize highly passive safe and compact reactors. This paper is a detailed report including all major results of the MRX design study.

  14. A new conceptual model of the formation of coral skeleton

    NASA Astrophysics Data System (ADS)

    Juillet-Leclerc, A.

    2006-12-01

    Scleractinian corals constitute one of the major groups of calcifying animals. During a long time their skeleton has been considered as purely mineral and all the features not consistent with this concept were called " vital effects ". However, biology plays a key role in the skeleton genesis. Recent technological advances provided enough evidences to propose a new conceptual model of coral skeleton growth. Ion microprobe carried out both trace element and isotope analyses, which stressed the high variability of these geochemical tracers. It indicates that all measurements obtained at millimeter-length scale, especially data used for paleoclimatic purpose, are bulk data. The analyses performed on individual microstructures previously identified by SEMS observation revealed that the two different microstructures highlighted in coral skeleton present a specific geochemical signature. We have thus to explain how two specific microstructures could derive from a unique calcifying fluid. On the other hand, several methods converged to show that a thin organic matrix surrounds growth units at micro/nanometer size scale. The presence of organic compounds could alter the equilibrium thermodynamics of the mineral growth surface by modifying energy landscape. Knowing that chemical environment of each microstructure could be different according the nature of the growth units we assume that it induces different mechanism of deposition. By combining results from different approaches we deduce that kinetics is not restricted to isotopic fractionation. We conclude that coral aragonite deposit is dominated by a kinetic chemical disequilibrium and governed by supersaturation law. We demonstrate that this conceptual model is consistent with the observations and measurements earlier performed and coral remains the most relevant archive of the tropical ocean than ever.

  15. Southern marl prairies conceptual ecological model

    USGS Publications Warehouse

    Davis, S.M.; Loftus, W.F.; Gaiser, E.E.; Huffman, A.E.

    2005-01-01

    About 190,000 ha of higher-elevation marl prairies flank either side of Shark River Slough in the southern Everglades. Water levels typically drop below the ground surface each year in this landscape. Consequently, peat soil accretion is inhibited, and substrates consist either of calcitic marl produced by algal periphyton mats or exposed limestone bedrock. The southern marl prairies support complex mosaics of wet prairie, sawgrass sawgrass (Cladium jamaicense), tree islands, and tropical hammock communities and a high diversity of plant species. However, relatively short hydroperiods and annual dry downs provide stressful conditions for aquatic fauna, affecting survival in the dry season when surface water is absent. Here, we present a conceptual ecological model developed for this landscape through scientific concensus, use of empirical data, and modeling. The two major societal drivers affecting the southern marl prairies are water management practices and agricultural and urban development. These drivers lead to five groups of ecosystem stressors: loss of spatial extent and connectivity, shortened hydroperiod and increased drought severity, extended hydroperiod and drying pattern reversals, introduction and spread of non-native trees, and introduction and spread of non-native fishes. Major ecological attributes include periphyton mats, plant species diversity and community mosaic, Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), marsh fishes and associated aquatic fauna prey base, American alligator (Alligator mississippiensis), and wading bird early dry season foraging. Water management and development are hypothesized to have a negative effect on the ecological attributes of the southern marl prairies in the following ways. Periphyton mats have decreased in cover in areas where hydroperiod has been significantly reduced and changed in community composition due to inverse responses to increased nutrient availability. Plant species diversity and

  16. Conjunctival melanoma: a review of conceptual and treatment advances

    PubMed Central

    Lim, Li-Anne; Madigan, Michele C; Conway, R Max

    2013-01-01

    The aim of this study was to review the available literature and identify recent advances in the classification and management of conjunctival melanoma (CM) for clinicians working in this field. English-based articles were identified using the MEDLINE® database, and additional cited works not detected in the initial search were also obtained. Articles were assessed according to the Australian National Health and Medical Research Council levels of evidence criteria. Review of the literature indicated that the current classification and management of CM is predominantly based upon primarily nonrandomized, single-institution, retrospective case series. While these studies provide the basis for the recent seventh edition of the tumor node metastasis staging classification, this classification more accurately reflects the current knowledge of prognostic factors for CM. Application of this revised classification system together with prospective trials will provide the opportunity for future consistent and comparable data collection across centers, and it will improve the quality of evidence upon which current classification and management of CM is based. Furthermore, the high risk of local recurrence with current standard management suggests that adjuvant therapy, particularly mitomycin C and/or brachytherapy, may improve outcomes regardless of clinical staging. Finally, the use of sentinel lymph node biopsy may have significant benefit for a select group of CM patients. PMID:23515569

  17. Conceptual model for partnership and sustainability in global health.

    PubMed

    Leffers, Jeanne; Mitchell, Emma

    2011-01-01

    Although nursing has a long history of service to the global community, the profession lacks a theoretical and empirical base for nurses to frame their global practice. A study using grounded theory methodology to investigate partnership and sustainability for global health led to the development of a conceptual model. Interviews were conducted with 13 global health nurse experts. Themes from the interviews were: components for engagement, mutual goal setting, cultural bridging, collaboration, capacity building, leadership, partnership, ownership, and sustainability. Next, the identified themes were reviewed in the literature in order to evaluate their conceptual relationships. Finally, careful comparison of the interview transcripts and the supporting literature led to the Conceptual Framework for Partnership and Sustainability in Global Health Nursing. The model posits that engagement and partnership must precede any planning and intervention in order to create sustainable interventions. This conceptual framework will offer nurses important guidance for global health nursing practice.

  18. A Conceptual Model To Assist Educational Leaders Manage Change.

    ERIC Educational Resources Information Center

    Cochren, John R.

    This paper presents a conceptual model to help school leaders manage change effectively. The model was developed from a literature review of theory development and model construction. Specifically, the paper identifies the major components that inhibit organizational change, and synthesizes the most salient features of these components through a…

  19. A Conceptual Model of Career Development to Enhance Academic Motivation

    ERIC Educational Resources Information Center

    Collins, Nancy Creighton

    2010-01-01

    The purpose of this study was to develop, refine, and validate a conceptual model of career development to enhance the academic motivation of community college students. To achieve this end, a straw model was built from the theoretical and empirical research literature. The model was then refined and validated through three rounds of a Delphi…

  20. A conceptual model of nontornadic supercell thunderstorms

    NASA Astrophysics Data System (ADS)

    Majcen, Mario

    2009-07-01

    This study uses dual-Doppler observations of nontornadic supercells obtained by ground-based mobile Doppler radars and idealized numerical simulations in order to develop a conceptual model of a nontornadic supercell, particularly at low levels and on the submesocyclone scale. In the first part of this dissertation, five nontornadic supercell thunderstorms are analyzed using high-resolution dual-Doppler radar data obtained by a pair of mobile ground-based radars. Three out of five observed supercells had well-developed low-level rotation. The observed low-level kinematic fields of the nontornadic supercells with low-level rotation are compared to the low-level kinematic fields of tornadic supercells that have been previously documented. It is determined that the observed low-level kinematic structure of nontornadic supercells is qualitatively very similar to the low-level kinematic structure of tornadic supercells, notably two out of three observed nontornadic storms had a "bent-back" rear-flank gust front just like the tornadic supercells, and one of those also had a dual rear-flank gust front, a feature that previously has been observed only in tornadic supercells. The low-level mesocyclone in the nontornadic supercells extends to the lowest analysis level in the three cases having low-level rotation, but the low-level circulation in nontornadic mesocyclones is much weaker than in tornadic mesocyclones. Also, the divergence associated with rear-flank downdrafts is stronger in nontornadic supercells than in tornadic supercells. Vortex line analyses in the observed nontornadic storms show that the vorticity field structure is consistent with baroclinic generation of horizontal vorticity and subsequent tilting into the vertical by an updraft, as has been shown in recent observational and numerical simulation studies. In the second part of this study, a series of idealized, dry three-dimensional numerical simulations are used to gain some understanding of the

  1. A conceptual model for determining career choice of CHROME alumna based on farmer's conceptual models

    NASA Astrophysics Data System (ADS)

    Moore, Lisa Simmons

    This qualitative program evaluation examines the career decision-making processes and career choices of nine, African American women who participated in the Cooperating Hampton Roads Organization for Minorities in Engineering (CHROME) and who graduated from urban, rural or suburban high schools in the year 2000. The CHROME program is a nonprofit, pre-college intervention program that encourages underrepresented minority and female students to enter science, technically related, engineering, and math (STEM) career fields. The study describes career choices and decisions made by each participant over a five-year period since high school graduation. Data was collected through an Annual Report, Post High School Questionnaires, Environmental Support Questionnaires, Career Choice Questionnaires, Senior Reports, and standardized open-ended interviews. Data was analyzed using a model based on Helen C. Farmer's Conceptual Models, John Ogbu's Caste Theory and Feminist Theory. The CHROME program, based on its stated goals and tenets, was also analyzed against study findings. Findings indicated that participants received very low levels of support from counselors and teachers to pursue STEM careers and high levels of support from parents and family, the CHROME program and financial backing. Findings of this study also indicated that the majority of CHROME alumna persisted in STEM careers. The most successful participants, in terms of undergraduate degree completion and occupational prestige, were the African American women who remained single, experienced no critical incidents, came from a middle class to upper middle class socioeconomic background, and did not have children.

  2. Student Flow Models: A Review and Conceptualization.

    ERIC Educational Resources Information Center

    Lovell, C. C.

    The manner in which students move through the system of higher education--changing majors, leaving the system for undetermined periods and then returning, failing and repeating courses, continuing on for advanced and professional degrees--can have a significant effect on the planning and managing of institutions. The purpose of this paper is to…

  3. Guide for developing conceptual models for ecological risk assessments

    SciTech Connect

    Suter, G.W., II

    1996-05-01

    Ecological conceptual models are the result of the problem formulation phase of an ecological risk assessment, which is an important component of the Remedial Investigation process. They present hypotheses of how the site contaminants might affect the site ecology. The contaminant sources, routes, media, routes, and endpoint receptors are presented in the form of a flow chart. This guide is for preparing the conceptual models; use of this guide will standardize the models so that they will be of high quality, useful to the assessment process, and sufficiently consistent so that connections between sources of exposure and receptors can be extended across operable units (OU). Generic conceptual models are presented for source, aquatic integrator, groundwater integrator, and terrestrial OUs.

  4. Conceptual adsorption models and open issues pertaining to performance assessment

    SciTech Connect

    Serne, R.J.

    1991-10-01

    Recently several articles have been published that question the appropriateness of the distribution coefficient, Rd, concept to quantify radionuclide migration. Several distinct issues are raised by various critics. In this paper I provide some perspective on issues surrounding the modeling of nuclide retardation. The first section defines adsorption terminology and discusses various adsorption processes. The next section describes five commonly used adsorption conceptual models, specifically emphasizing what attributes that affect adsorption are explicitly accommodated in each model. I also review efforts to incorporate each adsorption model into performance assessment transport computer codes. The five adsorption conceptual models are (1) the constant Rd model, (2) the parametric Rd model, (3) isotherm adsorption models, (4) mass-action adsorption models, and (5) surface-complexation with electrostatics models. The final section discusses the adequacy of the distribution ratio concept, the adequacy of transport calculations that rely on constant retardation factors and the status of incorporating sophisticated adsorption models into transport codes.

  5. Geologic Conceptual Model of Mosul Dam

    DTIC Science & Technology

    2007-09-01

    options in the Groundwater Modeling System (GMS) • MODFLOW modeling • ERDC Hydrogeologic Flow Model for Mosul Dam Most of the workshop time was...L., T. J. Budge, A. M. Lemon, and A. K. Zundel. 2002. Generating MODFLOW grids from boundary representation solid models. Ground Water 40(2):194-200...Modeling System (GMS) • MODFLOW Modeling • ERDC Hydrogeologic Flow Model for Mosul Dam ERDC TR-07-6 31 Trainees To fully benefit from the

  6. Newman Unit 1 advanced solar repowering advanced conceptual design. Final report

    SciTech Connect

    1982-04-01

    The Newman Unit 1 solar repowering design is a water/steam central receiver concept supplying superheated steam. The work reported is to develop a refined baseline conceptual design that has potential for construction and operation by 1986, makes use of existing solar thermal technology, and provides the best economics for this application. Trade studies performed in the design effort are described, both for the conceptual design of the overall system and for the subsystem conceptual design. System-level functional requirements, design, operation, performance, cost, safety, environmental, institutional, and regulatory considerations are described. Subsystems described include the collector, receiver, fossil energy, electrical power generating, and master control subsystems, site and site facilities. The conceptual design, cost, and performance of each subsystem is discussed at length. A detailed economic analysis of the repowered unit is made to realistically assess the economics of the first repowered unit using present cost data for a limited production level for solar hardware. Finally, a development plan is given, including the design, procurement, construction, checkout, startup, performance validation, and commercial operation. (LEW)

  7. Conceptual model for transferring information between small watersheds

    USGS Publications Warehouse

    Cleaves, E.T.

    2003-01-01

    Stream and watershed management and restoration can be greatly facilitated through use of physiographic landform classification to organize and communicate natural resource, hazard, and environmental information at a broad scale (1:250,000) as illustrated by the Piedmont and Coastal Plain Provinces in Maryland, or at a small scale (1:24,000) as illustrated using divisions and zones combined with a conceptual model. The conceptual model brings together geology, surficial processes, landforms and land use change information at the small watershed scale and facilitates transfer of information from one small watershed to another with similar geology and landforms. Stream flow, sediment erosion, and water quality illustrate the use of the model.

  8. Advanced turbine systems program conceptual design and product development: Quarterly report, November 1993--January 1994

    SciTech Connect

    1995-01-01

    This report describes progress made in the advanced turbine systems program conceptual design and product development. The topics of the report include selection of the Allison GFATS, castcool technology development for industrial engines test plan and schedule, code development and background gathering phase for the ultra low NOx combustion technology task, active turbine clearance task, and water vapor/air mixture cooling of turbine vanes task.

  9. Supporting user-defined granularities in a spatiotemporal conceptual model

    USGS Publications Warehouse

    Khatri, V.; Ram, S.; Snodgrass, R.T.; O'Brien, G. M.

    2002-01-01

    Granularities are integral to spatial and temporal data. A large number of applications require storage of facts along with their temporal and spatial context, which needs to be expressed in terms of appropriate granularities. For many real-world applications, a single granularity in the database is insufficient. In order to support any type of spatial or temporal reasoning, the semantics related to granularities needs to be embedded in the database. Specifying granularities related to facts is an important part of conceptual database design because under-specifying the granularity can restrict an application, affect the relative ordering of events and impact the topological relationships. Closely related to granularities is indeterminacy, i.e., an occurrence time or location associated with a fact that is not known exactly. In this paper, we present an ontology for spatial granularities that is a natural analog of temporal granularities. We propose an upward-compatible, annotation-based spatiotemporal conceptual model that can comprehensively capture the semantics related to spatial and temporal granularities, and indeterminacy without requiring new spatiotemporal constructs. We specify the formal semantics of this spatiotemporal conceptual model via translation to a conventional conceptual model. To underscore the practical focus of our approach, we describe an on-going case study. We apply our approach to a hydrogeologic application at the United States Geologic Survey and demonstrate that our proposed granularity-based spatiotemporal conceptual model is straightforward to use and is comprehensive.

  10. C-130 Advanced Technology Center wing box conceptual design/cost study

    NASA Technical Reports Server (NTRS)

    Whitehead, R. S.; Foreman, C. R.; Silva, K.

    1992-01-01

    A conceptual design was developed by Northrop/LTV for an advanced C-130 Center Wing Box (CWB) which could meet the severe mission requirements of the SOF C-130 aircraft. The goals for the advanced technology CWB relative to the current C-130H CWB were: (1) the same acquisition cost; (2) lower operating support costs; (3) equal or lower weight; (4) a 30,000 hour service life for the SOF mission; and (5) minimum impact on the current maintenance concept. Initially, the structural arrangement, weight, external and internal loads, fatigue spectrum, flutter envelope and design criteria for the SOF C-130 aircraft CWB were developed. An advanced materials assessment was then conducted to determine the suitability of advanced materials for a 1994 production availability and detailed trade studies were performed on candidate CWB conceptual designs. Finally, a life-cycle cost analysis was performed on the advanced CWB. The study results showed that a hybrid composite/metallic CWB could meet the severe SOF design requirements, reduce the CWB weight by 14 pct., and was cost effective relative to an all metal beefed up C-130H CWB.

  11. Revisiting "Discrepancy Analysis in Continuing Medical Education: A Conceptual Model"

    ERIC Educational Resources Information Center

    Fox, Robert D.

    2011-01-01

    Based upon a review and analysis of selected literature, the author presents a conceptual model of discrepancy analysis evaluation for planning, implementing, and assessing the impact of continuing medical education (CME). The model is described in terms of its value as a means of diagnosing errors in the development and implementation of CME. The…

  12. A Conceptual Model for Episodes of Acute, Unscheduled Care.

    PubMed

    Pines, Jesse M; Lotrecchiano, Gaetano R; Zocchi, Mark S; Lazar, Danielle; Leedekerken, Jacob B; Margolis, Gregg S; Carr, Brendan G

    2016-10-01

    We engaged in a 1-year process to develop a conceptual model representing an episode of acute, unscheduled care. Acute, unscheduled care includes acute illnesses (eg, nausea and vomiting), injuries, or exacerbations of chronic conditions (eg, worsening dyspnea in congestive heart failure) and is delivered in emergency departments, urgent care centers, and physicians' offices, as well as through telemedicine. We began with a literature search to define an acute episode of care and to identify existing conceptual models used in health care. In accordance with this information, we then drafted a preliminary conceptual model and collected stakeholder feedback, using online focus groups and concept mapping. Two technical expert panels reviewed the draft model, examined the stakeholder feedback, and discussed ways the model could be improved. After integrating the experts' comments, we solicited public comment on the model and made final revisions. The final conceptual model includes social and individual determinants of health that influence the incidence of acute illness and injury, factors that affect care-seeking decisions, specific delivery settings where acute care is provided, and outcomes and costs associated with the acute care system. We end with recommendations for how researchers, policymakers, payers, patients, and providers can use the model to identify and prioritize ways to improve acute care delivery.

  13. Conceptual model for assessment of inhalation exposure: defining modifying factors.

    PubMed

    Tielemans, Erik; Schneider, Thomas; Goede, Henk; Tischer, Martin; Warren, Nick; Kromhout, Hans; Van Tongeren, Martie; Van Hemmen, Joop; Cherrie, John W

    2008-10-01

    The present paper proposes a source-receptor model to schematically describe inhalation exposure to help understand the complex processes leading to inhalation of hazardous substances. The model considers a stepwise transfer of a contaminant from the source to the receptor. The conceptual model is constructed using three components, i.e. (i) the source, (ii) various transmission compartments and (iii) the receptor, and describes the contaminant's emission and its pattern of transport. Based on this conceptual model, a list of nine mutually independent principal modifying factors (MFs) is proposed: activity emission potential, substance emission potential, localized control, separation, segregation, dilution, worker behavior, surface contamination and respiratory protection. These MFs describe the exposure process at a high level of abstraction so that the model can be generically applicable. A list of exposure determinants underlying each of these principal MFs is proposed to describe the exposure process at a more detailed level. The presented conceptual model is developed in conjunction with an activity taxonomy as described in a separate paper. The proposed conceptual model and MFs should be seen as 'building blocks' for development of higher tier exposure models.

  14. Conceptual definition of a technology development mission for advanced solar dynamic power systems

    NASA Technical Reports Server (NTRS)

    Migra, R. P.

    1986-01-01

    An initial conceptual definition of a technology development mission for advanced solar dynamic power systems is provided, utilizing a space station to provide a dedicated test facility. The advanced power systems considered included Brayton, Stirling, and liquid metal Rankine systems operating in the temperature range of 1040 to 1400 K. The critical technologies for advanced systems were identified by reviewing the current state of the art of solar dynamic power systems. The experimental requirements were determined by planning a system test of a 20 kWe solar dynamic power system on the space station test facility. These requirements were documented via the Mission Requirements Working Group (MRWG) and Technology Development Advocacy Group (TDAG) forms. Various concepts or considerations of advanced concepts are discussed. A preliminary evolutionary plan for this technology development mission was prepared.

  15. From models to performance assessment: the conceptualization problem.

    PubMed

    Bredehoeft, John D

    2003-01-01

    Today, models are ubiquitous tools for ground water analyses. The intent of this paper is to explore philosophically the role of the conceptual model in analysis. Selection of the appropriate conceptual model is an a priori decision by the analyst. Calibration is an integral part of the modeling process. Unfortunately a wrong or incomplete conceptual model can often be adequately calibrated; good calibration of a model does not ensure a correct conceptual model. Petroleum engineers have another term for calibration; they refer to it as history matching. A caveat to the idea of history matching is that we can make a prediction with some confidence equal to the period of the history match. In other words, if we have matched a 10-year history, we can predict for 10 years with reasonable confidence; beyond 10 years the confidence in the prediction diminishes rapidly. The same rule of thumb applies to ground water model analyses. Nuclear waste disposal poses a difficult problem because the time horizon, 1000 years or longer, is well beyond the possibility of the history match (or period of calibration) in the traditional analysis. Nonetheless, numerical models appear to be the tool of choice for analyzing the safety of waste facilities. Models have a well-recognized inherent uncertainty. Performance assessment, the technique for assessing the safety of nuclear waste facilities, involves an ensemble of cascading models. Performance assessment with its ensemble of models multiplies the inherent uncertainty of the single model. The closer we can approach the idea of a long history with which to match the models, even models of nuclear waste facilities, the more confidence we will have in the analysis (and the models, including performance assessment). This thesis argues for prolonged periods of observation (perhaps as long as 300 to 1000 years) before a nuclear waste facility is finally closed.

  16. Advanced Chemistry Basins Model

    SciTech Connect

    William Goddard; Mario Blanco; Lawrence Cathles; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2002-11-10

    The DOE-funded Advanced Chemistry Basin model project is intended to develop a public domain, user-friendly basin modeling software under PC or low end workstation environment that predicts hydrocarbon generation, expulsion, migration and chemistry. The main features of the software are that it will: (1) afford users the most flexible way to choose or enter kinetic parameters for different maturity indicators; (2) afford users the most flexible way to choose or enter compositional kinetic parameters to predict hydrocarbon composition (e.g., gas/oil ratio (GOR), wax content, API gravity, etc.) at different kerogen maturities; (3) calculate the chemistry, fluxes and physical properties of all hydrocarbon phases (gas, liquid and solid) along the primary and secondary migration pathways of the basin and predict the location and intensity of phase fractionation, mixing, gas washing, etc.; and (4) predict the location and intensity of de-asphaltene processes. The project has be operative for 36 months, and is on schedule for a successful completion at the end of FY 2003.

  17. The School Media Center: A Conceptual Model.

    ERIC Educational Resources Information Center

    Hodson, Yvonne D.

    1979-01-01

    Describes a model for a school media center which will serve as a strategic learning facility. The model is based upon research in both media and education dealing with behavioristic psychology, personality theory, cognitive psychology, and theories of learning as information processing. (Author/FM)

  18. Problem Solving, Modeling, and Local Conceptual Development.

    ERIC Educational Resources Information Center

    Lesh, Richard; Harel, Guershon

    2003-01-01

    Describes similarities and differences between modeling cycles and stages of development. Includes examples of relevant constructs underlying children's developing ways of thinking about fractions, ratios, rates, proportions, or other mathematical ideas. Concludes that modeling cycles appear to be local or situated versions of the general stages…

  19. A Conceptual Model for Leadership Transition

    ERIC Educational Resources Information Center

    Manderscheid, Steven V.; Ardichvili, Alexandre

    2008-01-01

    The purpose of this study was to develop a model of leadership transition based on an integrative review of literature. The article establishes a compelling case for focusing on leadership transitions as an area for study and leadership development practitioner intervention. The proposed model in this study identifies important success factors…

  20. A Multiperspectival Conceptual Model of Transformative Meaning Making

    ERIC Educational Resources Information Center

    Freed, Maxine

    2009-01-01

    Meaning making is central to transformative learning, but little work has explored how meaning is constructed in the process. Moreover, no meaning-making theory adequately captures its characteristics and operations during radical transformation. The purpose of this dissertation was to formulate and specify a multiperspectival conceptual model of…

  1. Designing Public Library Websites for Teens: A Conceptual Model

    ERIC Educational Resources Information Center

    Naughton, Robin Amanda

    2012-01-01

    The main goal of this research study was to develop a conceptual model for the design of public library websites for teens (TLWs) that would enable designers and librarians to create library websites that better suit teens' information needs and practices. It bridges a gap in the research literature between user interface design in human-computer…

  2. Childhood Adultification in Economically Disadvantaged Families: A Conceptual Model

    ERIC Educational Resources Information Center

    Burton, Linda

    2007-01-01

    This article presents an emergent conceptual model of childhood adultification and economic disadvantage derived from 5 longitudinal ethnographies of children and adolescents growing up in low-income families. Childhood adultification involves contextual, social, and developmental processes in which youth are prematurely, and often…

  3. A New Conceptual Model for Understanding International Students' College Needs

    ERIC Educational Resources Information Center

    Alfattal, Eyad

    2016-01-01

    This study concerns the theory and practice of international marketing in higher education with the purpose of exploring a conceptual model for understanding international students' needs in the context of a four-year college in the United States. A transcendental phenomenological design was employed to investigate the essence of international…

  4. A Conceptual Model of the World of Work.

    ERIC Educational Resources Information Center

    VanRooy, William H.

    The conceptual model described in this paper resulted from the need to organize a body of knowledge related to the world of work which would enable curriculum developers to prepare accurate, realistic instructional materials. The world of work is described by applying Malinowski's scientific study of the structural components of culture. It is…

  5. Developing a Conceptual Model of STEAM Teaching Practices

    ERIC Educational Resources Information Center

    Quigley, Cassie F.; Herro, Dani; Jamil, Faiza M.

    2017-01-01

    STEAM, where the "A" represents arts and humanities, is considered a transdisciplinary learning process that has the potential to increase diverse participation in science, technology, engineering, and math (STEM) fields. However, a well-defined conceptual model that clearly articulates essential components of the STEAM approach is…

  6. Higher Education as Student Development: A Conceptual Model.

    ERIC Educational Resources Information Center

    Richardson, Robert L.

    A sample of 462 student affairs professionals responded to a survey questionnaire designed to conceptualize a model institution of higher education committed to facilitating the development of the whole student. The respondents represented 74% of a randomly selected population sample drawn from the membership lists of ACPA, NASPA, and NAWDAC. The…

  7. Conceptualizations of Creativity: Comparing Theories and Models of Giftedness

    ERIC Educational Resources Information Center

    Miller, Angie L.

    2012-01-01

    This article reviews seven different theories of giftedness that include creativity as a component, comparing and contrasting how each one conceptualizes creativity as a part of giftedness. The functions of creativity vary across the models, suggesting that while the field of gifted education often cites the importance of creativity, the…

  8. Annex to 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect

    Not Available

    1988-05-01

    The Annex to the 7-GeV Advanced Photon Source Conceptual Design Report updates the Conceptual Design Report of 1987 (CDR-87) to include the results of further optimization and changes of the design during the past year. The design changes can be summarized as affecting three areas: the accelerator system, conventional facilities, and experimental systems. Most of the changes in the accelerator system result from inclusion of a positron accumulator ring (PAR), which was added at the suggestion of the 1987 DOE Review Committee, to speed up the filling rate of the storage ring. The addition of the PAR necessitates many minor changes in the linac system, the injector synchrotron, and the low-energy beam transport lines. 63 figs., 18 tabs.

  9. EUReKA! A Conceptual Model of Emotion Understanding.

    PubMed

    Castro, Vanessa L; Cheng, Yanhua; Halberstadt, Amy G; Grühn, Daniel

    2016-07-01

    The field of emotion understanding is replete with measures, yet lacks an integrated conceptual organizing structure. To identify and organize skills associated with the recognition and knowledge of emotions, and to highlight the focus of emotion understanding as localized in the self, in specific others, and in generalized others, we introduce the conceptual framework of Emotion Understanding in Recognition and Knowledge Abilities (EUReKA). We then categorize fifty-six existing methods of emotion understanding within this framework to highlight current gaps and future opportunities in assessing emotion understanding across the lifespan. We hope the EUReKA model provides a systematic and integrated framework for conceptualizing and measuring emotion understanding for future research.

  10. Fostering radical conceptual change through dual-situated learning model

    NASA Astrophysics Data System (ADS)

    She, Hsiao-Ching

    2004-02-01

    This article examines how the Dual-Situated Learning Model (DSLM) facilitates a radical change of concepts that involve the understanding of matter, process, and hierarchical attributes. The DSLM requires knowledge of students' prior beliefs of science concepts and the nature of these concepts. In addition, DSLM also serves two functions: it creates dissonance with students' prior knowledge by challenging their epistemological and ontological beliefs about science concepts, and it provides essential mental sets for students to reconstruct a more scientific view of the concepts. In this study, the concept heat transfer: heat conduction and convection, which requires an understanding of matter, process, and hierarchical attributes, was chosen to examine how DSLM can facilitate radical conceptual change among students. Results show that DSLM has great potential to foster a radical conceptual change process in learning heat transfer. Radical conceptual change can definitely be achieved and does not necessarily involve a slow or gradual process.

  11. A new conceptual model of convection

    SciTech Connect

    Walcek, C.

    1995-09-01

    Classical cumulus parameterizations assume that cumulus clouds are entraining plumes of hot air rising through the atmosphere. However, ample evidence shows that clouds cannot be simulated using this approach. Dr. Walcek suggests that cumulus clouds can be reasonably simulated by assuming that buoyant plumes detrain mass as they rise through the atmosphere. Walcek successfully simulates measurements of tropical convection using this detraining model of cumulus convection. Comparisons with measurements suggest that buoyant plumes encounter resistance to upward movement as they pass through dry layers in the atmosphere. This probably results from turbulent mixing and evaporation of cloud water, which generates negatively buoyant mixtures which detrain from the upward moving plume. This mass flux model of detraining plumes is considerably simpler than existing mass flux models, yet reproduces many of the measured effects associated with convective activity. 1 fig.

  12. Learning strategies: a synthesis and conceptual model

    NASA Astrophysics Data System (ADS)

    Hattie, John A. C.; Donoghue, Gregory M.

    2016-08-01

    The purpose of this article is to explore a model of learning that proposes that various learning strategies are powerful at certain stages in the learning cycle. The model describes three inputs and outcomes (skill, will and thrill), success criteria, three phases of learning (surface, deep and transfer) and an acquiring and consolidation phase within each of the surface and deep phases. A synthesis of 228 meta-analyses led to the identification of the most effective strategies. The results indicate that there is a subset of strategies that are effective, but this effectiveness depends on the phase of the model in which they are implemented. Further, it is best not to run separate sessions on learning strategies but to embed the various strategies within the content of the subject, to be clearer about developing both surface and deep learning, and promoting their associated optimal strategies and to teach the skills of transfer of learning. The article concludes with a discussion of questions raised by the model that need further research.

  13. A Conceptual Model of Preschool Assessment.

    ERIC Educational Resources Information Center

    Paget, Kathleen D.; Nagle, Richard J.

    1986-01-01

    An ecologically-based model is offered to guide the assessment activities of school psychologists at the preschool level. The uniqueness of the preschool population, the multidimensional structure of the assessment process, and the connection between assessment results and the intervention strategies are emphasized. (Author/LMO)

  14. Performance potential of an advanced technology Mach 3 turbojet engine installed on a conceptual high-speed civil transport

    NASA Technical Reports Server (NTRS)

    Morris, Shelby J., Jr.; Geiselhart, Karl A.; Coen, Peter G.

    1989-01-01

    The performance of an advanced technology conceptual turbojet optimized for a high-speed civil aircraft is presented. This information represents an estimate of performance of a Mach 3 Brayton (gas turbine) cycle engine optimized for minimum fuel burned at supersonic cruise. This conceptual engine had no noise or environmental constraints imposed upon it. The purpose of this data is to define an upper boundary on the propulsion performance for a conceptual commercial Mach 3 transport design. A comparison is presented demonstrating the impact of the technology proposed for this conceptual engine on the weight and other characteristics of a proposed high-speed civil transport. This comparison indicates that the advanced technology turbojet described could reduce the gross weight of a hypothetical Mach 3 high-speed civil transport design from about 714,000 pounds to about 545,000 pounds. The aircraft with the baseline engine and the aircraft with the advanced technology engine are described.

  15. Advanced X-Ray Timing Array Mission: Conceptual Spacecraft Design Study

    NASA Technical Reports Server (NTRS)

    Hopkins, R. C.; Johnson, L.; Thomas, H. D.; Wilson-Hodge, C. A.; Baysinger, M.; Maples, C. D.; Fabisinski, L.L.; Hornsby, L.; Thompson, K. S.; Miernik, J. H.

    2011-01-01

    The Advanced X-Ray Timing Array (AXTAR) is a mission concept for submillisecond timing of bright galactic x-ray sources. The two science instruments are the Large Area Timing Array (LATA) (a collimated instrument with 2-50-keV coverage and over 3 square meters of effective area) and a Sky Monitor (SM), which acts as a trigger for pointed observations of x-ray transients. The spacecraft conceptual design team developed two spacecraft concepts that will enable the AXTAR mission: A minimal configuration to be launched on a Taurus II and a larger configuration to be launched on a Falcon 9 or similar vehicle.

  16. Conceptual Commitments of the LIDA Model of Cognition

    NASA Astrophysics Data System (ADS)

    Franklin, Stan; Strain, Steve; McCall, Ryan; Baars, Bernard

    2013-06-01

    Significant debate on fundamental issues remains in the subfields of cognitive science, including perception, memory, attention, action selection, learning, and others. Psychology, neuroscience, and artificial intelligence each contribute alternative and sometimes conflicting perspectives on the supervening problem of artificial general intelligence (AGI). Current efforts toward a broad-based, systems-level model of minds cannot await theoretical convergence in each of the relevant subfields. Such work therefore requires the formulation of tentative hypotheses, based on current knowledge, that serve to connect cognitive functions into a theoretical framework for the study of the mind. We term such hypotheses "conceptual commitments" and describe the hypotheses underlying one such model, the Learning Intelligent Distribution Agent (LIDA) Model. Our intention is to initiate a discussion among AGI researchers about which conceptual commitments are essential, or particularly useful, toward creating AGI agents.

  17. Validation of the conceptual anatomical model of the lung airway.

    PubMed

    Fleming, John S; Sauret, Veronique; Conway, Joy H; Martonen, Ted B

    2004-01-01

    The conceptual anatomical model of the lung airway considers each lung volume divided into ten concentric shells. It specifies the volume of each airway generation in each shell, using Weibel morphometry. This study updates and validates the model and evaluates the errors obtained when using it to estimate inhaled aerosol deposition per generation from spatial imaging data. A comparison of different airway models describing the volume per generation, including data from CT images of a lung cast and a human subject, was performed. A revised version of the conceptual model was created, using the average volume per generation from these data. The new model was applied to derive the aerosol deposition per generation from 24 single photon emission computed tomography (SPECT) studies. Analysis errors were assessed by applying the same calculations but using airway models based on the minimum and maximum volumes per generation. The mean shell position of each generation in the average model was not significantly different from either CT model. However there were differences between the volumes per generation of the different models. The root mean square differences between bronchial airways deposition fraction (generations 2-8) obtained from the maximum and minimum models compared to the new average model was 0.66 percentage points (14%). For the conducting airways deposition fraction (generations 2-15) this was 1.66 percentage points (12%). The conceptual model is consistent with CT measurements of airway geometry. The errors resulting from using a generic airway model to interpret 3D radionuclide image data have been defined.

  18. Advanced Turbine Systems Program -- Conceptual design and product development. Quarterly report, August 1--October 31, 1995

    SciTech Connect

    1995-12-31

    The objective of Phase 2 of the Advanced Turbine Systems (ATS) Program is to provide the conceptual design and product development plan for an ultra high efficiency, environmentally superior and cost competitive industrial gas turbine system to be commercialized by the year 2000. A secondary objective is to begin early development of technologies critical to the success of ATS. This quarterly report, addresses only Task 4, conversion of a gas turbine to a coal-fired gas turbine, which was completed during the quarter and the nine subtasks included in Task 8, design and test of critical components. These nine subtasks address six ATS technologies as follows: catalytic combustion; recuperator; autothermal fuel reformer; high temperature turbine disc; advanced control system (MMI); and ceramic materials.

  19. Task 6 -- Advanced turbine systems program conceptual design and product development

    SciTech Connect

    1996-01-10

    The Allison Engine Company has completed the Task 6 Conceptual Design and Analysis of Phase 2 of the Advanced Turbine System (ATS) contract. At the heart of Allison`s system is an advanced simple cycle gas turbine engine. This engine will incorporate components that ensure the program goals are met. Allison plans to commercialize the ATS demonstrator and market a family of engines incorporating this technology. This family of engines, ranging from 4.9 MW to 12 MW, will be suitable for use in all industrial engine applications, including electric power generation, mechanical drive, and marine propulsion. In the field of electric power generation, the engines will be used for base load, standby, cogeneration, and distributed generation applications.

  20. Advanced turbine systems program conceptual design and product development. Annual report, August 1994--July 1995

    SciTech Connect

    1995-11-01

    This report summarizes the tasks completed under this project during the period from August 1, 1994 through July 31, 1994. The objective of the study is to provide the conceptual design and product development plan for an ultra high efficiency, environmentally superior and cost-competitive industrial gas turbine system to be commercialized by the year 2000. The tasks completed include a market study for the advanced turbine system; definition of an optimized recuperated gas turbine as the prime mover meeting the requirements of the market study and whose characteristics were, in turn, used for forecasting the total advanced turbine system (ATS) future demand; development of a program plan for bringing the ATS to a state of readiness for field test; and demonstration of the primary surface recuperator ability to provide the high thermal effectiveness and low pressure loss required to support the proposed ATS cycle.

  1. Advanced turbine systems program conceptual design and product development. Quarterly report, August--October, 1994

    SciTech Connect

    1995-01-01

    The objective of Phase 2 of the Advanced Turbine Systems (ATS) Program is to provide the conceptual design and product development plan for an ultra-high efficiency, environmentally superior and cost competitive industrial gas turbine system to be commercialized by the year 2000. A secondary objective is to begin early development of technologies critical to the success of ATS. During this report period, the following tasks were completed: Market study; System definition and analysis; and Integrated program plans. Progress on Task 8, Design and Test of Critical Components, is also discussed. This particular task includes expanded materials and component research covering recuperators, combustion, autothermal fuel reformation, ceramics application and advanced gas turbine system controls.

  2. Conceptual Model for Selenium Cycling in the Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Johnson, W. P.; Conover, M. R.; Wurtsbaugh, W. A.; Adams, J.

    2006-12-01

    The conceptual model for Selenium cycling in the Great Salt Lake was developed to guide investigations in support of determining an open water selenium standard for the Great Salt Lake. The motivation to determine this particular selenium standard derives from public concern for a plan to allow disposal of reverse osmosis (RO) concentrate in the GSL, which would contain elevated concentrations of major and trace elements, including selenium. The development of an open water standard for selenium requires a working knowledge of the biological significance of existing selenium concentrations in the Great Salt Lake, as well as a working understanding of the likely changes of these concentrations over time given existing and proposed loads to the system. This working knowledge" is being represented in a conceptual model that accounts for selenium in various stocks" in the system (e.g. water, sediment, biota) and the flow" of selenium between stocks (e.g., precipitation and settling, volatilization, bioconcentration). It illustrates the critical pathway of selenium in the Great Salt Lake from water, to microorganisms, to brine shrimp and brine flies, to birds, and to their eggs. It also addresses the complexity of the GSL system: a) Spatially diverse, being comprised by four distinct bays and two layers, with major differences in salinity among their waters. b) Temporally dynamic, due to seasonal and inter-annual variations in runoff. The conceptual model is presently descriptive, but will serve as the basis for a semi-quantitative model that will be fed by data accumulated during subsequent investigations.

  3. Conceptual classification model for Sustainable Flood Retention Basins.

    PubMed

    Scholz, Miklas; Sadowski, Adam J

    2009-01-01

    The aim of this paper is to recommend a rapid conceptual classification model for Sustainable Flood Retention Basins (SFRB) used to control runoff in a temperate climate. An SFRB is an aesthetically pleasing retention basin predominantly used for flood protection adhering to sustainable drainage and best management practices. The classification model was developed on the basis of a database of 141 SFRB using the River Rhine catchment in Baden (part of Baden-Württemberg, Germany) as a case study. It is based on an agglomerative cluster analysis and is intended to be used by engineers and scientists to adequately classify the following different types of SFRB: Hydraulic Flood Retention Basin, Traditional Flood Retention Basin, Sustainable Flood Retention Wetland, Aesthetic Flood Retention Wetland, Integrated Flood Retention Wetland and Natural Flood Retention Wetland. The selection of classification variables was supported by a principal component analysis. The identification of SFRB in the data set was based on a Ward cluster analysis of 34 weighted classification variables. Scoring tables were defined to enable the assignment of the six SFRB definitions to retention basins in the data set. The efficiency of these tables was based on a scoring system which gave the conceptual model for the example case study sites an overall efficiency of approximately 60% (as opposed to 17% by chance). This conceptual classification model should be utilized to improve communication by providing definitions for SFRB types. The classification definitions are likely to be applicable for other regions with both temperate oceanic and temperate continental climates.

  4. eLac - Conceptual Model for Flood Management

    NASA Astrophysics Data System (ADS)

    Rata, Marius; Florentin Draghia, Aurelian; Drobot, Radu; Matreata, Marius; Corbus, Ciprian

    2015-04-01

    This article reviews the conceptual model of the decision support system (DSS) for flood management activities introduced in the scope of e-LAC project. Following the general system architecture which has an emphasize on the water management decision processes, hydrologic and hydraulic models are introduced and discussed according to their specific DSS integration potential. Three directions are discussed in dedicated sections corresponding to the main modules defined in the conceptual model : the Water Basin Management Module (mainly implements the management decision flow, but manages also data exchange between hydrologic modeling module and hydraulic modeling module, allow real time visualization for hydrological data), the Hydrologic Modeling Module (manages all the modeling functionalities of rainfalls - runoff processes, providing continuous hydrologic forecasts with a variable time-step depending on the actual basin situation) and the Hydraulic Modeling Module (computes the flood's waves routing having as boundary upstream conditions the discharge hydrographs, generated both by catchment's upper area, river tributaries and inter-basins, respectively the rating curves, water level hydrograph or water surface slope as downstream condition). The GIS concepts are contextually reviewed based on their use as geospatial database for water management modeling, integration within hydrologic time courses, hydraulic modeling (from both software and management perspective), expert knowledge or mathematical modeling results (knowledge database, rules).

  5. Scientific and conceptual flaws of coercive treatment models in addiction.

    PubMed

    Uusitalo, Susanne; van der Eijk, Yvette

    2016-01-01

    In conceptual debates on addiction, neurobiological research has been used to support the idea that addicted drug users lack control over their addiction-related actions. In some interpretations, this has led to coercive treatment models, in which, the purpose is to 'restore' control. However, neurobiological studies that go beyond what is typically presented in conceptual debates paint a different story. In particular, they indicate that though addiction has neurobiological manifestations that make the addictive behaviour difficult to control, it is possible for individuals to reverse these manifestations through their own efforts. Thus, addicted individuals should not be considered incapable of making choices voluntarily, simply on the basis that addiction has neurobiological manifestations, and coercive treatment models of addiction should be reconsidered in this respect.

  6. CONCEPTUAL MODELS AND METHODS TO GUIDE DIAGNOSTIC RESEARCH INTO CAUSES OF IMPAIRMENT TO AQUATIC ECOSYSTEMS

    EPA Science Inventory

    Methods and conceptual models to guide the development of tools for diagnosing the causes of biological impairment within aquatic ecosystems of the United States are described in this report. The conceptual models developed here address nutrients, suspended and bedded sediments (...

  7. Advanced Usage of Vehicle Sketch Pad for CFD-Based Conceptual Design

    NASA Technical Reports Server (NTRS)

    Ordaz, Irian; Li, Wu

    2013-01-01

    Conceptual design is the most fluid phase of aircraft design. It is important to be able to perform large scale design space exploration of candidate concepts that can achieve the design intent to avoid more costly configuration changes in later stages of design. This also means that conceptual design is highly dependent on the disciplinary analysis tools to capture the underlying physics accurately. The required level of analysis fidelity can vary greatly depending on the application. Vehicle Sketch Pad (VSP) allows the designer to easily construct aircraft concepts and make changes as the design matures. More recent development efforts have enabled VSP to bridge the gap to high-fidelity analysis disciplines such as computational fluid dynamics and structural modeling for finite element analysis. This paper focuses on the current state-of-the-art geometry modeling for the automated process of analysis and design of low-boom supersonic concepts using VSP and several capability-enhancing design tools.

  8. Conceptual Model of Climate Change Impacts at LANL

    SciTech Connect

    Dewart, Jean Marie

    2016-05-17

    Goal 9 of the LANL FY15 Site Sustainability Plan (LANL 2014a) addresses Climate Change Adaptation. As part of Goal 9, the plan reviews many of the individual programs the Laboratory has initiated over the past 20 years to address climate change impacts to LANL (e.g. Wildland Fire Management Plan, Forest Management Plan, etc.). However, at that time, LANL did not yet have a comprehensive approach to climate change adaptation. To fill this gap, the FY15 Work Plan for the LANL Long Term Strategy for Environmental Stewardship and Sustainability (LANL 2015) included a goal of (1) establishing a comprehensive conceptual model of climate change impacts at LANL and (2) establishing specific climate change indices to measure climate change and impacts at Los Alamos. Establishing a conceptual model of climate change impacts will demonstrate that the Laboratory is addressing climate change impacts in a comprehensive manner. This paper fulfills the requirement of goal 1. The establishment of specific indices of climate change at Los Alamos (goal 2), will improve our ability to determine climate change vulnerabilities and assess risk. Future work will include prioritizing risks, evaluating options/technologies/costs, and where appropriate, taking actions. To develop a comprehensive conceptual model of climate change impacts, we selected the framework provided in the National Oceanic and Atmospheric Administration (NOAA) Climate Resilience Toolkit (http://toolkit.climate.gov/).

  9. The application of ecohydrological groundwater indicators to hydrogeological conceptual models.

    PubMed

    Lewis, Jeff

    2012-01-01

    This article reviews the application of ecohydrological indicators to hydrogeological conceptual models for earth-scientists with little or no botanical training. Ecohydrological indicators are plants whose presence or morphology can provide data about the hydrogeological setting. By examining the literature from the fields of ecohydrology, hydrogeology, geobotany, and ecology, this article summarizes what is known about groundwater indicator plants, their potential for providing information about the aquifer, and how this data can be a cost-effective addition to hydrogeological conceptual models. We conclude that the distribution and morphology of ecohydrological groundwater indicator plants can be useful to hydrogeologists in certain circumstances. They are easiest to evaluate in arid and semiarid climates. Ecohydrological groundwater indicators can provide information about the absolute depth to the water table, patterns of groundwater fluctuation, and the mineralization of the aquifer. It is shown that an understanding of the meteorological conditions of a region is often necessary to accurately interpret groundwater indicator plants and that useful data is usually obtained by observing patterns of vegetation behavior rather than interpreting individual plants. The most serious limitations to applying this source of information to hydrogeological conceptual models are the limited data in the literature and the regional nature of many indicator plants. The physical and physiological indications of the plants exist, but little effort has been made to interpret them. This article concludes by outlining several potential lines of research that could further the usefulness of ecohydrological groundwater indicators to the hydrogeological community.

  10. Conceptual Models in Health Informatics Research: A Literature Review and Suggestions for Development

    PubMed Central

    2016-01-01

    Background Contributing to health informatics research means using conceptual models that are integrative and explain the research in terms of the two broad domains of health science and information science. However, it can be hard for novice health informatics researchers to find exemplars and guidelines in working with integrative conceptual models. Objectives The aim of this paper is to support the use of integrative conceptual models in research on information and communication technologies in the health sector, and to encourage discussion of these conceptual models in scholarly forums. Methods A two-part method was used to summarize and structure ideas about how to work effectively with conceptual models in health informatics research that included (1) a selective review and summary of the literature of conceptual models; and (2) the construction of a step-by-step approach to developing a conceptual model. Results The seven-step methodology for developing conceptual models in health informatics research explained in this paper involves (1) acknowledging the limitations of health science and information science conceptual models; (2) giving a rationale for one’s choice of integrative conceptual model; (3) explicating a conceptual model verbally and graphically; (4) seeking feedback about the conceptual model from stakeholders in both the health science and information science domains; (5) aligning a conceptual model with an appropriate research plan; (6) adapting a conceptual model in response to new knowledge over time; and (7) disseminating conceptual models in scholarly and scientific forums. Conclusions Making explicit the conceptual model that underpins a health informatics research project can contribute to increasing the number of well-formed and strongly grounded health informatics research projects. This explication has distinct benefits for researchers in training, research teams, and researchers and practitioners in information, health, and other

  11. Incorporating agricultural land cover in conceptual rainfall runoff models

    NASA Astrophysics Data System (ADS)

    Euser, Tanja; Hrachowitz, Markus; Winsemius, Hessel; Savenije, Hubert

    2015-04-01

    Incorporating spatially variable information is a frequently discussed option to increase the performance of (semi) distributed conceptual rainfall runoff models. One of the methods to do this is by using these spatially variable information to delineate Hydrological Response Units (HRUs) within a catchment. This study tests whether the incorporation of an additional agricultural HRU in a conceptual hydrological model can better reflect the spatial differences in runoff generation and therefore improve the simulation of the wetting phase in autumn. The study area is the meso-scale Ourthe catchment in Belgium. A previous study in this area showed that spatial patterns in runoff generation were already better represented by incorporation of a wetland and a hillslope HRU, compared to a lumped model structure. The influences which are considered by including an agriculture HRU are increased drainage speed due to roads, plough pans and increased infiltration excess overland flow (drainage pipes area only limited present), and variable vegetation patterns due to sowing and harvesting. In addition, the vegetation is not modelled as a static resistance towards evaporation, but the Jarvis stress functions are used to increase the realism of the modelled transpiration; in land-surface models the Jarvis stress functions are already often used for modelling transpiration. The results show that an agricultural conceptualisation in addition to wetland and hillslope conceptualisations leads to small improvements in the modelled discharge. However, the influence is larger on the representation of spatial patterns and the modelled contributions of different HRUs to the total discharge.

  12. HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)"

    NASA Astrophysics Data System (ADS)

    Savenije, H. H. G.

    2010-07-01

    Heterogeneity and complexity of hydrological processes offer substantial challenges to the hydrological modeller. Some hydrologists try to tackle this problem by introducing more and more detail in their models, or by setting-up more and more complicated models starting from basic principles at the smallest possible level. As we know, this reductionist approach leads to ever higher levels of equifinality and predictive uncertainty. On the other hand, simple, lumped and parsimonious models may be too simple to be realistic or representative of the dominant hydrological processes. In this commentary, a new model approach is proposed that tries to find the middle way between complex distributed and simple lumped modelling approaches. Here we try to find the right level of simplification while avoiding over-simplification. Paraphrasing Einstein, the maxim is: make a model as simple as possible, but not simpler than that. The approach presented is process based, but not physically based in the traditional sense. Instead, it is based on a conceptual representation of the dominant physical processes in certain key elements of the landscape. The essence of the approach is that the model structure is made dependent on a limited number of landscape classes in which the topography is the main driver, but which can include geological, geomorphological or land-use classification. These classes are then represented by lumped conceptual models that act in parallel. The advantage of this approach over a fully distributed conceptualisation is that it retains maximum simplicity while taking into account observable landscape characteristics.

  13. What is recovery? A conceptual model and explication.

    PubMed

    Jacobson, N; Greenley, D

    2001-04-01

    This paper describes a conceptual model of recovery from mental illness developed to aid the state of Wisconsin in moving toward its goal of developing a "recovery-oriented" mental health system. In the model, recovery refers to both internal conditions experienced by persons who describe themselves as being in recovery--hope, healing, empowerment, and connection--and external conditions that facilitate recovery--implementation of the principle of human rights, a positive culture of healing, and recovery-oriented services. The aim of the model is to link the abstract concepts that define recovery with specific strategies that systems, agencies, and individuals can use to facilitate it.

  14. Conceptual Model of Quantities, Units, Dimensions, and Values

    NASA Technical Reports Server (NTRS)

    Rouquette, Nicolas F.; DeKoenig, Hans-Peter; Burkhart, Roger; Espinoza, Huascar

    2011-01-01

    JPL collaborated with experts from industry and other organizations to develop a conceptual model of quantities, units, dimensions, and values based on the current work of the ISO 80000 committee revising the International System of Units & Quantities based on the International Vocabulary of Metrology (VIM). By providing support for ISO 80000 in SysML via the International Vocabulary of Metrology (VIM), this conceptual model provides, for the first time, a standard-based approach for addressing issues of unit coherence and dimensional analysis into the practice of systems engineering with SysML-based tools. This conceptual model provides support for two kinds of analyses specified in the International Vocabulary of Metrology (VIM): coherence of units as well as of systems of units, and dimension analysis of systems of quantities. To provide a solid and stable foundation, the model for defining quantities, units, dimensions, and values in SysML is explicitly based on the concepts defined in VIM. At the same time, the model library is designed in such a way that extensions to the ISQ (International System of Quantities) and SI Units (Systeme International d Unites) can be represented, as well as any alternative systems of quantities and units. The model library can be used to support SysML user models in various ways. A simple approach is to define and document libraries of reusable systems of units and quantities for reuse across multiple projects, and to link units and quantity kinds from these libraries to Unit and QuantityKind stereotypes defined in SysML user models.

  15. Life cycle cost modeling of conceptual space vehicles

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles

    1993-01-01

    This paper documents progress to date by the University of Dayton on the development of a life cycle cost model for use during the conceptual design of new launch vehicles and spacecraft. This research is being conducted under NASA Research Grant NAG-1-1327. This research effort changes the focus from that of the first two years in which a reliability and maintainability model was developed to the initial development of a life cycle cost model. Cost categories are initially patterned after NASA's three axis work breakdown structure consisting of a configuration axis (vehicle), a function axis, and a cost axis. The focus will be on operations and maintenance costs and other recurring costs. Secondary tasks performed concurrent with the development of the life cycle costing model include continual support and upgrade of the R&M model. The primary result of the completed research will be a methodology and a computer implementation of the methodology to provide for timely cost analysis in support of the conceptual design activities. The major objectives of this research are: to obtain and to develop improved methods for estimating manpower, spares, software and hardware costs, facilities costs, and other cost categories as identified by NASA personnel; to construct a life cycle cost model of a space transportation system for budget exercises and performance-cost trade-off analysis during the conceptual and development stages; to continue to support modifications and enhancements to the R&M model; and to continue to assist in the development of a simulation model to provide an integrated view of the operations and support of the proposed system.

  16. Thinking Upstream: A 25-Year Retrospective and Conceptual Model Aimed at Reducing Health Inequities.

    PubMed

    Butterfield, Patricia G

    Thinking upstream was first introduced into the nursing vernacular in 1990 with the goal of advancing broad and context-rich perspectives of health. Initially invoked as conceptual framing language, upstream precepts were subsequently adopted and adapted by a generation of thoughtful nursing scholars. Their work reduced health inequities by redirecting actions further up etiologic pathways and by emphasizing economic, political, and environmental health determinants. US health care reform has fostered a much broader adoption of upstream language in policy documents. This article includes a semantic exploration of thinking upstream and a new model, the Butterfield Upstream Model for Population Health (BUMP Health).

  17. A Systems Perspective on Situation Awareness I: Conceptual Framework, Modeling, and Quantitative Measurement

    DTIC Science & Technology

    2003-05-01

    A Systems Perspective on Situation Awareness I: Conceptual Framework , Modeling, and Quantitative Measurement Alex Kirlik (University of...I: Conceptual Framework , Modeling, and Quantitative Measurement 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...Systems Perspective on Situation Awareness I: Conceptual Framework , Modeling, and Quantitative Measurement ALEX KIRLIK Institute of Aviation

  18. Applying Human Capital Management to Model Manpower Readiness: A Conceptual Framework

    DTIC Science & Technology

    2005-12-01

    CAPITAL MANAGEMENT TO MODEL MANPOWER READINESS: A CONCEPTUAL FRAMEWORK by Pert Chin Ngin December 2005 Associate Advisors: William R...Management to Model Manpower Readiness: A Conceptual Framework 6. AUTHOR(S) Pert Chin Ngin 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S...distribution is unlimited. APPLYING HUMAN CAPITAL MANAGEMENT TO MODEL MANPOWER READINESS: A CONCEPTUAL FRAMEWORK Pert Chin Ngin MAJOR, Republic of

  19. CROSS-CULTURAL VALIDITY OF A SPHERICAL CONCEPTUAL MODEL FOR PARENT BEHAVIOR.

    ERIC Educational Resources Information Center

    SCHAEFER, EARL S.; AND OTHERS

    THE CROSS-CULTURAL VALIDITY OF AN EVOLVING CONCEPTUAL MODEL FOR PARENT BEHAVIOR WAS INVESTIGATED. PREVIOUS RESEARCH STUDIES SUGGEST THAT THE PARENT BEHAVIOR DIMENSIONS OF SEVERAL CONCEPTUAL MODELS COULD BE INTEGRATED BY VISUALIZING THESE DIMENSIONS AS PLOTTED ON THE SURFACE OF A SPHERE. THE PROPOSED SPHERICAL CONCEPTUAL MODEL WAS OBTAINED USING…

  20. Integrating O/S models during conceptual design, part 1

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles E.

    1994-01-01

    The University of Dayton is pleased to submit this report to the National Aeronautics and Space Administration (NASA), Langley Research Center, which integrates a set of models for determining operational capabilities and support requirements during the conceptual design of proposed space systems. This research provides for the integration of the reliability and maintainability (R&M) model, both new and existing simulation models, and existing operations and support (O&S) costing equations in arriving at a complete analysis methodology. Details concerning the R&M model and the O&S costing model may be found in previous reports accomplished under this grant (NASA Research Grant NAG1-1327). In the process of developing this comprehensive analysis approach, significant enhancements were made to the R&M model, updates to the O&S costing model were accomplished, and a new simulation model developed. This is the 1st part of a 3 part technical report.

  1. Misrepresentation and amendment of soil moisture in conceptual hydrological modelling

    NASA Astrophysics Data System (ADS)

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Although many conceptual models are very effective in simulating river runoff, their soil moisture schemes are generally not realistic in comparison with the reality (i.e., getting the right answers for the wrong reasons). This study reveals two significant misrepresentations in those models through a case study using the Xinanjiang model which is representative of many well-known conceptual hydrological models. The first is the setting of the upper limit of its soil moisture at the field capacity, due to the 'holding excess runoff' concept (i.e., runoff begins on repletion of its storage to the field capacity). The second is neglect of capillary rise of water movement. A new scheme is therefore proposed to overcome those two issues. The amended model is as effective as its original form in flow modelling, but represents more logically realistic soil water processes. The purpose of the study is to enable the hydrological model to get the right answers for the right reasons. Therefore, the new model structure has a better capability in potentially assimilating soil moisture observations to enhance its real-time flood forecasting accuracy. The new scheme is evaluated in the Pontiac catchment of the USA through a comparison with satellite observed soil moisture. The correlation between the XAJ and the observed soil moisture is enhanced significantly from 0.64 to 0.70. In addition, a new soil moisture term called SMDS (Soil Moisture Deficit to Saturation) is proposed to complement the conventional SMD (Soil Moisture Deficit).

  2. HESS Opinions "Topography driven conceptual modelling (FLEX-Topo)"

    NASA Astrophysics Data System (ADS)

    Savenije, H. H. G.

    2010-12-01

    Heterogeneity and complexity of hydrological processes offer substantial challenges to the hydrological modeller. Some hydrologists try to tackle this problem by introducing more and more detail in their models, or by setting-up more and more complicated models starting from basic principles at the smallest possible level. As we know, this reductionist approach leads to ever higher levels of equifinality and predictive uncertainty. On the other hand, simple, lumped and parsimonious models may be too simple to be realistic or representative of the dominant hydrological processes. In this commentary, a new approach is proposed that tries to find the middle way between complex distributed and simple lumped modelling approaches. Here we try to find the right level of simplification while avoiding over-simplification. Paraphrasing Einstein, the maxim is: make a model as simple as possible, but not simpler than that. The approach presented is process based, but not physically based in the traditional sense. Instead, it is based on a conceptual representation of the dominant physical processes in certain key elements of the landscape. The essence of the approach is that the model structure is made dependent on a limited number of landscape classes in which the topography is the main driver, but which can include geological, geomorphological or land-use classification. These classes are then represented by lumped conceptual models that act in parallel. The advantage of this approach over a fully distributed conceptualisation is that it retains maximum simplicity while taking into account observable landscape characteristics.

  3. Improving conceptual models of water and carbon transfer through peat

    USGS Publications Warehouse

    McKenzie, Jeffery M.; Siegel, Donald I.; Rosenberry, Donald O.; Baird, Andrew J.; Belyea, Lisa R.; Comas, Xavier; Reeve, A.S.; Slater, Lee D.

    2009-01-01

    Northern peatlands store 500 × 1015 g of organic carbon and are very sensitive to climate change. There is a strong conceptual model of sources, sinks, and pathways of carbon within peatlands, but challenges remain both in understanding the hydrogeology and the linkages between carbon cycling and peat pore water flow. In this chapter, research findings from the glacial Lake Agassiz peatlands are used to develop a conceptual framework for peatland hydrogeology and identify four challenges related to northern peatlands yet to be addressed: (1) develop a better understanding of the extent and net impact of climate-driven groundwater flushing in peatlands; (2) quantify the complexities of heterogeneity on pore water flow and, in particular, reconcile contradictions between peatland hydrogeologic interpretations and isotopic data; (3) understand the hydrogeologic implications of free-phase methane production, entrapment, and release in peatlands; and (4) quantify the impact of arctic and subarctic warming on peatland hydrogeology and its linkage to carbon cycling.

  4. Design Oriented Structural Modeling for Airplane Conceptual Design Optimization

    NASA Technical Reports Server (NTRS)

    Livne, Eli

    1999-01-01

    The main goal for research conducted with the support of this grant was to develop design oriented structural optimization methods for the conceptual design of airplanes. Traditionally in conceptual design airframe weight is estimated based on statistical equations developed over years of fitting airplane weight data in data bases of similar existing air- planes. Utilization of such regression equations for the design of new airplanes can be justified only if the new air-planes use structural technology similar to the technology on the airplanes in those weight data bases. If any new structural technology is to be pursued or any new unconventional configurations designed the statistical weight equations cannot be used. In such cases any structural weight estimation must be based on rigorous "physics based" structural analysis and optimization of the airframes under consideration. Work under this grant progressed to explore airframe design-oriented structural optimization techniques along two lines of research: methods based on "fast" design oriented finite element technology and methods based on equivalent plate / equivalent shell models of airframes, in which the vehicle is modelled as an assembly of plate and shell components, each simulating a lifting surface or nacelle / fuselage pieces. Since response to changes in geometry are essential in conceptual design of airplanes, as well as the capability to optimize the shape itself, research supported by this grant sought to develop efficient techniques for parametrization of airplane shape and sensitivity analysis with respect to shape design variables. Towards the end of the grant period a prototype automated structural analysis code designed to work with the NASA Aircraft Synthesis conceptual design code ACS= was delivered to NASA Ames.

  5. Conceptual Modeling in the Time of the Revolution: Part II

    NASA Astrophysics Data System (ADS)

    Mylopoulos, John

    Conceptual Modeling was a marginal research topic at the very fringes of Computer Science in the 60s and 70s, when the discipline was dominated by topics focusing on programs, systems and hardware architectures. Over the years, however, the field has moved to centre stage and has come to claim a central role both in Computer Science research and practice in diverse areas, such as Software Engineering, Databases, Information Systems, the Semantic Web, Business Process Management, Service-Oriented Computing, Multi-Agent Systems, Knowledge Management, and more. The transformation was greatly aided by the adoption of standards in modeling languages (e.g., UML), and model-based methodologies (e.g., Model-Driven Architectures) by the Object Management Group (OMG) and other standards organizations. We briefly review the history of the field over the past 40 years, focusing on the evolution of key ideas. We then note some open challenges and report on-going research, covering topics such as the representation of variability in conceptual models, capturing model intentions, and models of laws.

  6. Operations and support cost modeling of conceptual space vehicles

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles

    1994-01-01

    The University of Dayton is pleased to submit this annual report to the National Aeronautics and Space Administration (NASA) Langley Research Center which documents the development of an operations and support (O&S) cost model as part of a larger life cycle cost (LCC) structure. It is intended for use during the conceptual design of new launch vehicles and spacecraft. This research is being conducted under NASA Research Grant NAG-1-1327. This research effort changes the focus from that of the first two years in which a reliability and maintainability model was developed to the initial development of an operations and support life cycle cost model. Cost categories were initially patterned after NASA's three axis work breakdown structure consisting of a configuration axis (vehicle), a function axis, and a cost axis. A revised cost element structure (CES), which is currently under study by NASA, was used to established the basic cost elements used in the model. While the focus of the effort was on operations and maintenance costs and other recurring costs, the computerized model allowed for other cost categories such as RDT&E and production costs to be addressed. Secondary tasks performed concurrent with the development of the costing model included support and upgrades to the reliability and maintainability (R&M) model. The primary result of the current research has been a methodology and a computer implementation of the methodology to provide for timely operations and support cost analysis during the conceptual design activities.

  7. A Conceptual Model for Multidimensional Analysis of Documents

    NASA Astrophysics Data System (ADS)

    Ravat, Franck; Teste, Olivier; Tournier, Ronan; Zurlfluh, Gilles

    Data warehousing and OLAP are mainly used for the analysis of transactional data. Nowadays, with the evolution of Internet, and the development of semi-structured data exchange format (such as XML), it is possible to consider entire fragments of data such as documents as analysis sources. As a consequence, an adapted multidimensional analysis framework needs to be provided. In this paper, we introduce an OLAP multidimensional conceptual model without facts. This model is based on the unique concept of dimensions and is adapted for multidimensional document analysis. We also provide a set of manipulation operations.

  8. Conceptual model of the Klamath Falls, Oregon geothermal area

    SciTech Connect

    Prucha, R.H.; Benson, S.M.; Witherspoon, P.A.

    1987-01-01

    Over the last 50 years significant amounts of data have been obtained from the Klamath Falls geothermal resource. To date, the complexity of the system has stymied researchers, leading to the development of only very generalized hydrogeologic and geothermal models of the area. Recently, the large quantity of available temperature data have been re-evaluated, revealing new information on subsurface heat flow and locations of faults in the system. These inferences are supported by borehole, geochemical, geophysical, and hydrologic data. Based on re-evaluation of all available data, a detailed conceptual model for the Klamath Falls geothermal resource is proposed.

  9. Conceptual Model of the Klamath Falls, Oregon Geothermal Area

    SciTech Connect

    Prucha, R.H.; Benson, S.M.; Witherspoon, P.A.

    1987-01-20

    Over the last 50 years significant amounts of data have been obtained from the Klamath Falls geothermal resource. To date, the complexity of the system has stymied researchers, leading to the development of only very generalized hydrogeologic and geothermal models of the area. Recently, the large quantity of available temperature data have been re-evaluated, revealing new information on subsurface heat flow and locations of faults in the system. These inferences are supported by borehole, geochemical, geophysical, and hydrologic data. Based on re-evaluation of all available data, a detailed conceptual model for the Klamath Falls geothermal resource is proposed. 1 tab., 8 figs., 21 refs.

  10. Conceptual design of an advanced Stirling conversion system for terrestrial power generation

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A free piston Stirling engine coupled to an electric generator or alternator with a nominal kWe power output absorbing thermal energy from a nominal 100 square meter parabolic solar collector and supplying electric power to a utility grid was identified. The results of the conceptual design study of an Advanced Stirling Conversion System (ASCS) were documented. The objectives are as follows: define the ASCS configuration; provide a manufacturability and cost evaluation; predict ASCS performance over the range of solar input required to produce power; estimate system and major component weights; define engine and electrical power condidtioning control requirements; and define key technology needs not ready by the late 1980s in meeting efficiency, life, cost, and with goalds for the ASCS.

  11. Advanced Turbine Systems program conceptual design and product development. Quarterly report, February--April 1994

    SciTech Connect

    1995-02-01

    Task 8.5 (active clearance control) was replaced with a test of the 2600F prototype turbine (Task 8.1T). Test 8.1B (Build/Teardown of prototype turbine) was added. Tasks 4 (conversion of gas-fired turbine to coal-fired turbine) and 5 (market study) were kicked off in February. Task 6 (conceptual design) was also initiated. Task 8.1 (advanced cooling technology) now has an approved test plan. Task 8.4 (ultra low NOx combustion technology) has completed the code development and background gathering phase. Task 8.6 (two-phase cooling of turbine vanes) is proceeding well; initial estimates indicate that nearly 2/3 of required cooling flow can be eliminated.

  12. Advanced conceptual design report solid waste retrieval facility, phase I, project W-113

    SciTech Connect

    Smith, K.E.

    1994-03-21

    Project W-113 will provide the equipment and facilities necessary to retrieve suspect transuranic (TRU) waste from Trench 04 of the 218W-4C burial ground. As part of the retrieval process, waste drums will be assayed, overpacked, vented, head-gas sampled, and x-rayed prior to shipment to the Phase V storage facility in preparation for receipt at the Waste Receiving and Processing Facility (WRAP). Advanced Conceptual Design (ACD) studies focused on project items warranting further definition prior to Title I design and areas where the potential for cost savings existed. This ACD Report documents the studies performed during FY93 to optimize the equipment and facilities provided in relation to other SWOC facilities and to provide additional design information for Definitive Design.

  13. Advanced conceptual design report: T Plant secondary containment and leak detection upgrades. Project W-259

    SciTech Connect

    Hookfin, J.D.

    1995-05-12

    The T Plant facilities in the 200-West Area of the Hanford site were constructed in the early 1940s to produce nuclear materials in support of national defense activities. T Plant includes the 271-T facility, the 221-T facility, and several support facilities (eg, 2706-T), utilities, and tanks/piping systems. T Plant has been recommended as the primary interim decontamination facility for the Hanford site. Project W-259 will provide capital upgrades to the T Plant facilities to comply with Federal and State of Washington environmental regulations for secondary containment and leak detection. This document provides an advanced conceptual design concept that complies with functional requirements for the T Plant Secondary Containment and Leak Detection upgrades.

  14. Conceptual design of an advanced water/steam receiver for a solar thermal central power system

    NASA Astrophysics Data System (ADS)

    Wu, S. F.; Narayanan, T. V.; Gorman, D. N.

    1981-06-01

    This paper describes the conceptual design of an advanced water/steam receiver for a commercial-scale solar central receiver thermal power system. The objective was to develop a receiver concept featuring an optimum combination of cost, performance, and reliability. While interfaces with other major subsystems of the complete power plant were recognized, emphasis was on the design and performance of the receiver. The baseline thermal rating of this receiver was 550 MW, and the steam outlet conditions were 12,860 kPa and 516 C. After technical and economic evaluations, a quad-cavity, natural-circulation concept was selected as the preferred receiver design. It consists of four separate cavities in a single receiver unit, each cavity receiving concentrated solar energy from one quadrant of a surrounding heliostat field.

  15. Conceptual Change Texts in Chemistry Teaching: A Study on the Particle Model of Matter

    ERIC Educational Resources Information Center

    Beerenwinkel, Anne; Parchmann, Ilka; Grasel, Cornelia

    2011-01-01

    This study explores the effect of a conceptual change text on students' awareness of common misconceptions on the particle model of matter. The conceptual change text was designed based on principles of text comprehensibility, of conceptual change instruction and of instructional approaches how to introduce the particle model. It was evaluated in…

  16. Our evolving conceptual model of the coastal eutrophication problem

    USGS Publications Warehouse

    Cloern, James E.

    2001-01-01

    A primary focus of coastal science during the past 3 decades has been the question: How does anthropogenic nutrient enrichment cause change in the structure or function of nearshore coastal ecosystems? This theme of environmental science is recent, so our conceptual model of the coastal eutrophication problem continues to change rapidly. In this review, I suggest that the early (Phase I) conceptual model was strongly influenced by limnologists, who began intense study of lake eutrophication by the 1960s. The Phase I model emphasized changing nutrient input as a signal, and responses to that signal as increased phytoplankton biomass and primary production, decomposition of phytoplankton-derived organic matter, and enhanced depletion of oxygen from bottom waters. Coastal research in recent decades has identified key differences in the responses of lakes and coastal-estuarine ecosystems to nutrient enrichment. The contemporary (Phase II) conceptual model reflects those differences and includes explicit recognition of (1) system-specific attributes that act as a filter to modulate the responses to enrichment (leading to large differences among estuarine-coastal systems in their sensitivity to nutrient enrichment); and (2) a complex suite of direct and indirect responses including linked changes in: water transparency, distribution of vascular plants and biomass of macroalgae, sediment biogeochemistry and nutrient cycling, nutrient ratios and their regulation of phytoplankton community composition, frequency of toxic/harmful algal blooms, habitat quality for metazoans, reproduction/growth/survival of pelagic and benthic invertebrates, and subtle changes such as shifts in the seasonality of ecosystem functions. Each aspect of the Phase II model is illustrated here with examples from coastal ecosystems around the world. In the last section of this review I present one vision of the next (Phase III) stage in the evolution of our conceptual model, organized around 5

  17. Use of Numerical Groundwater Modeling to Evaluate Uncertainty in Conceptual Models of Recharge and Hydrostratigraphy

    SciTech Connect

    Pohlmann, Karl; Ye, Ming; Pohll, Greg; Chapman, Jenny

    2007-01-19

    Numerical groundwater models are based on conceptualizations of hydrogeologic systems that are by necessity developed from limited information and therefore are simplifications of real conditions. Each aspect (e.g. recharge, hydrostratigraphy, boundary conditions) of the groundwater model is often based on a single conceptual model that is considered to be the best representation given the available data. However, the very nature of their construction means that each conceptual model is inherently uncertain and the available information may be insufficient to refute plausible alternatives, thereby raising the possibility that the flow model is underestimating overall uncertainty. In this study we use the Death Valley Regional Flow System model developed by the U.S. Geological Survey as a framework to predict regional groundwater flow southward into Yucca Flat on the Nevada Test Site. An important aspect of our work is to evaluate the uncertainty associated with multiple conceptual models of groundwater recharge and subsurface hydrostratigraphy and quantify the impacts of this uncertainty on model predictions. In our study, conceptual model uncertainty arises from two sources: (1) alternative interpretations of the hydrostratigraphy in the northern portion of Yucca Flat where, owing to sparse data, the hydrogeologic system can be conceptualized in different ways, and (2) uncertainty in groundwater recharge in the region as evidenced by the existence of several independent approaches for estimating this aspect of the hydrologic system. The composite prediction of groundwater flow is derived from the regional model that formally incorporates the uncertainty in these alternative input models using the maximum likelihood Bayesian model averaging method. An assessment of the joint predictive uncertainty of the input conceptual models is also produced. During this process, predictions of the alternative models are weighted by model probability, which is the degree of

  18. Loss, Psychosis, and Chronic Suicidality in a Korean American Immigrant Man: Integration of Cultural Formulation Model and Multicultural Case Conceptualization

    PubMed Central

    Shea, Munyi; Yang, Lawrence H.; Leong, Frederick T. L.

    2011-01-01

    Culture shapes the nature, experience, and expression of psychopathology and help-seeking behavior across ethnically diverse groups. Although the study of psychopathology among Asian Americans has advanced, clinicians remain in need of culturally appropriate tools for the assessment and diagnosis of severe mental disorders including psychotic symptoms among Asian Americans. In this article, we present a brief overview of two culturally relevant conceptual tools: a) the Cultural Formulation Model, and b) the Multicultural Case Conceptualization approach. We use a case scenario to illustrate the integration of these two approaches in providing culturally responsive clinical conceptualization, assessment and treatment of a Korean American immigrant suffering from prominent psychiatric symptoms. We intend this discussion to engender further empirical work to advance our knowledge of the manifestation and experience of severe mental illness including psychotic disorders among Asian Americans, and contribute to culturally competent prevention and intervention of chronic and persistent mental illness within this group. PMID:21603157

  19. Combined Estimation of Hydrogeologic Conceptual Model and Parameter Uncertainty

    SciTech Connect

    Meyer, Philip D.; Ye, Ming; Neuman, Shlomo P.; Cantrell, Kirk J.

    2004-03-01

    The objective of the research described in this report is the development and application of a methodology for comprehensively assessing the hydrogeologic uncertainties involved in dose assessment, including uncertainties associated with conceptual models, parameters, and scenarios. This report describes and applies a statistical method to quantitatively estimate the combined uncertainty in model predictions arising from conceptual model and parameter uncertainties. The method relies on model averaging to combine the predictions of a set of alternative models. Implementation is driven by the available data. When there is minimal site-specific data the method can be carried out with prior parameter estimates based on generic data and subjective prior model probabilities. For sites with observations of system behavior (and optionally data characterizing model parameters), the method uses model calibration to update the prior parameter estimates and model probabilities based on the correspondence between model predictions and site observations. The set of model alternatives can contain both simplified and complex models, with the requirement that all models be based on the same set of data. The method was applied to the geostatistical modeling of air permeability at a fractured rock site. Seven alternative variogram models of log air permeability were considered to represent data from single-hole pneumatic injection tests in six boreholes at the site. Unbiased maximum likelihood estimates of variogram and drift parameters were obtained for each model. Standard information criteria provided an ambiguous ranking of the models, which would not justify selecting one of them and discarding all others as is commonly done in practice. Instead, some of the models were eliminated based on their negligibly small updated probabilities and the rest were used to project the measured log permeabilities by kriging onto a rock volume containing the six boreholes. These four

  20. Advanced Turbulence Modeling Concepts

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing

    2005-01-01

    The ZCET program developed at NASA Glenn Research Center is to study hydrogen/air injection concepts for aircraft gas turbine engines that meet conventional gas turbine performance levels and provide low levels of harmful NOx emissions. A CFD study for ZCET program has been successfully carried out. It uses the most recently enhanced National combustion code (NCC) to perform CFD simulations for two configurations of hydrogen fuel injectors (GRC- and Sandia-injector). The results can be used to assist experimental studies to provide quick mixing, low emission and high performance fuel injector designs. The work started with the configuration of the single-hole injector. The computational models were taken from the experimental designs. For example, the GRC single-hole injector consists of one air tube (0.78 inches long and 0.265 inches in diameter) and two hydrogen tubes (0.3 inches long and 0.0226 inches in diameter opposed at 180 degree). The hydrogen tubes are located 0.3 inches upstream from the exit of the air element (the inlet location for the combustor). To do the simulation, the single-hole injector is connected to a combustor model (8.16 inches long and 0.5 inches in diameter). The inlet conditions for air and hydrogen elements are defined according to actual experimental designs. Two crossing jets of hydrogen/air are simulated in detail in the injector. The cold flow, reacting flow, flame temperature, combustor pressure and possible flashback phenomena are studied. Two grid resolutions of the numerical model have been adopted. The first computational grid contains 0.52 million elements, the second one contains over 1.3 million elements. The CFD results have shown only about 5% difference between the two grid resolutions. Therefore, the CFD result obtained from the model of 1.3-million grid resolution can be considered as a grid independent numerical solution. Turbulence models built in NCC are consolidated and well tested. They can handle both coarse and

  1. A conceptual model of public medical service system based-on cell phone mobile platform

    NASA Astrophysics Data System (ADS)

    Fu, Hongjiao; Zhao, Yue

    In recent years, cell phones have played an increasingly important role in rapidly-developing global telecommunication services. At present, mobile business develops very fast. However, the development in other mobile service fields, such as public service, mobile medical service, etc, is still in its infant stage. Drawing on the experience of the 'doctor workstation project' which is cooperated by Renmin University of China and Norway Fredskorps Corporation, this paper discusses the research and implementation of the Doctor Workstation System based on cell phone mobile platform. From the practice of the Doctor Workstation System, the paper advances a conceptual model of public medical service system based-on cell phone mobile platform.

  2. Determinants of access to pediatric hospice care: A conceptual model.

    PubMed

    Lindley, Lisa C

    2015-04-01

    One of the many difficult moments for families of children with life-limiting illnesses is to make the decision to access pediatric hospice care. Although determinants that influence families' decisions to access pediatric hospice care have been recently identified, the relationship between these determinants and access to pediatric hospice care have not been explicated or grounded in accepted healthcare theories or models. Using the Andersen Behavioral Healthcare Utilization Model, this article presents a conceptual model describing the determinants of hospice access. Predisposing (demographic; social support; and knowledge, beliefs, and values), enabling (family and community resources) and need (perceived and evaluated needs) factors were identified through the use of hospice literature. The relationships among these factors are described and implications of the model for future study and practice are discussed.

  3. Updated Conceptual Model for the 300 Area Uranium Groundwater Plume

    SciTech Connect

    Zachara, John M.; Freshley, Mark D.; Last, George V.; Peterson, Robert E.; Bjornstad, Bruce N.

    2012-11-01

    The 300 Area uranium groundwater plume in the 300-FF-5 Operable Unit is residual from past discharge of nuclear fuel fabrication wastes to a number of liquid (and solid) disposal sites. The source zones in the disposal sites were remediated by excavation and backfilled to grade, but sorbed uranium remains in deeper, unexcavated vadose zone sediments. In spite of source term removal, the groundwater plume has shown remarkable persistence, with concentrations exceeding the drinking water standard over an area of approximately 1 km2. The plume resides within a coupled vadose zone, groundwater, river zone system of immense complexity and scale. Interactions between geologic structure, the hydrologic system driven by the Columbia River, groundwater-river exchange points, and the geochemistry of uranium contribute to persistence of the plume. The U.S. Department of Energy (DOE) recently completed a Remedial Investigation/Feasibility Study (RI/FS) to document characterization of the 300 Area uranium plume and plan for beginning to implement proposed remedial actions. As part of the RI/FS document, a conceptual model was developed that integrates knowledge of the hydrogeologic and geochemical properties of the 300 Area and controlling processes to yield an understanding of how the system behaves and the variables that control it. Recent results from the Hanford Integrated Field Research Challenge site and the Subsurface Biogeochemistry Scientific Focus Area Project funded by the DOE Office of Science were used to update the conceptual model and provide an assessment of key factors controlling plume persistence.

  4. Development of a conceptual model of cancer caregiver health literacy.

    PubMed

    Yuen, E Y N; Dodson, S; Batterham, R W; Knight, T; Chirgwin, J; Livingston, P M

    2016-03-01

    Caregivers play a vital role in caring for people diagnosed with cancer. However, little is understood about caregivers' capacity to find, understand, appraise and use information to improve health outcomes. The study aimed to develop a conceptual model that describes the elements of cancer caregiver health literacy. Six concept mapping workshops were conducted with 13 caregivers, 13 people with cancer and 11 healthcare providers/policymakers. An iterative, mixed methods approach was used to analyse and synthesise workshop data and to generate the conceptual model. Six major themes and 17 subthemes were identified from 279 statements generated by participants during concept mapping workshops. Major themes included: access to information, understanding of information, relationship with healthcare providers, relationship with the care recipient, managing challenges of caregiving and support systems. The study extends conceptualisations of health literacy by identifying factors specific to caregiving within the cancer context. The findings demonstrate that caregiver health literacy is multidimensional, includes a broad range of individual and interpersonal elements, and is influenced by broader healthcare system and community factors. These results provide guidance for the development of: caregiver health literacy measurement tools; strategies for improving health service delivery, and; interventions to improve caregiver health literacy.

  5. An analogue conceptual rainfall-runoff model for educational purposes

    NASA Astrophysics Data System (ADS)

    Herrnegger, Mathew; Riedl, Michael; Schulz, Karsten

    2016-04-01

    Conceptual rainfall-runoff models, in which runoff processes are modelled with a series of connected linear and non-linear reservoirs, remain widely applied tools in science and practice. Additionally, the concept is appreciated in teaching due to its somewhat simplicity in explaining and exploring hydrological processes of catchments. However, when a series of reservoirs are used, the model system becomes highly parametrized and complex and the traceability of the model results becomes more difficult to explain to an audience not accustomed to numerical modelling. Since normally the simulations are performed with a not visible digital code, the results are also not easily comprehensible. This contribution therefore presents a liquid analogue model, in which a conceptual rainfall-runoff model is reproduced by a physical model. This consists of different acrylic glass containers representing different storage components within a catchment, e.g. soil water or groundwater storage. The containers are equipped and connected with pipes, in which water movement represents different flow processes, e.g. surface runoff, percolation or base flow. Water from a storage container is pumped to the upper part of the model and represents effective rainfall input. The water then flows by gravity through the different pipes and storages. Valves are used for controlling the flows within the analogue model, comparable to the parameterization procedure in numerical models. Additionally, an inexpensive microcontroller-based board and sensors are used to measure storage water levels, with online visualization of the states as time series data, building a bridge between the analogue and digital world. The ability to physically witness the different flows and water levels in the storages makes the analogue model attractive to the audience. Hands-on experiments can be performed with students, in which different scenarios or catchment types can be simulated, not only with the analogue but

  6. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  7. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. One of the main objectives in the waste processing is to provide feed of a uniform slurry composition at a certain weight percentage (e.g. typically {approx}13 wt% at SRS) over an extended period of time. In preparation of the sludge for slurrying, several important questions have been raised with regard to sludge suspension and mixing of the solid suspension in the bulk of the tank: (1) How much time is required to prepare a slurry with a uniform solid composition? (2) How long will it take to suspend and mix the sludge for uniform composition in any particular waste tank? (3) What are good mixing indicators to answer the questions concerning sludge mixing stated above in a general fashion applicable to any waste tank/slurry pump geometry and fluid/sludge combination?

  8. Evaluation of ADAM/1 model for advanced coal extraction concepts

    NASA Technical Reports Server (NTRS)

    Deshpande, G. K.; Gangal, M. D.

    1982-01-01

    Several existing computer programs for estimating life cycle cost of mining systems were evaluated. A commercially available program, ADAM/1 was found to be satisfactory in relation to the needs of the advanced coal extraction project. Two test cases were run to confirm the ability of the program to handle nonconventional mining equipment and procedures. The results were satisfactory. The model, therefore, is recommended to the project team for evaluation of their conceptual designs.

  9. Assessing conceptual models for subsurface reactive transport of inorganic contaminants

    USGS Publications Warehouse

    Davis, James A.; Yabusaki, Steven B.; Steefel, Carl; Zachara, John M.; Curtis, Gary P.; Redden, George D.; Criscenti, Louise J.; Honeyman, Bruce D.

    2004-01-01

    In many subsurface situations where human health and environmental quality are at risk (e.g., contaminant hydrogeology petroleum extraction, carbon sequestration, etc.),scientists and engineers are being asked by federal agency decision-makers to predict the fate of chemical species under conditions where both reactions and transport are processes of first-order importance.In 2002, a working group (WG) was formed by representatives of the U.S. Geological Survey, Environmental Protection Agency, Department of Energy Nuclear Regulatory Commission, Department of Agriculture, and Army Engineer Research and Development Center to assess the role of reactive transport modeling (RTM) in addressing these situations. Specifically the goals of the WG are to (1) evaluate the state of the art in conceptual model development and parameterization for RTM, as applied to soil,vadose zone, and groundwater systems, and (2) prioritize research directions that would enhance the practical utility of RTM.

  10. A Conceptual Data Model for Flood Based on Cellular Automata Using Moving Object Data Model

    NASA Astrophysics Data System (ADS)

    Rachmatullah, R. S.; Azizah, F. N.

    2017-01-01

    Flood is considered as the costliest natural disaster in Indonesia due to its frequent occurrences as well as the extensive damage that it causes. Several studies provide different flood prediction models based on various hydrological factors. A lot of these models use grid-to-grid approach, making them suitable to be modelled as cellular automata. This paper presents a conceptual data model for flood based on cellular automata model using spatio-temporal data model, especially the moving object data model, as the modelling approach. The conceptual data model serves as the model of data structures within an environment for flood prediction simulation. We describe two conceptual data models as the alternatives to model the data structures of flood model. We create the data model based on the study to the factors that constitute the flood models. The first conceptual data model alternative focuses on the cell/grid as the main entity type. The changes of the states of the cells are stored as moving integer. The second alternative emphasizes on flood as the main entity type. The changes of the flood area are stored as moving region. Both alternatives introduce some advantages and disadvantages and the choice rely on the purpose of the use of the data model. We present a proposal of the architecture of a flood prediction system using cellular automata as the modelling approach. As the continuation of this work, further design and implementation details must be provided.

  11. Setting health research priorities using the CHNRI method: IV. Key conceptual advances

    PubMed Central

    Rudan, Igor

    2016-01-01

    Introduction Child Health and Nutrition Research Initiative (CHNRI) started as an initiative of the Global Forum for Health Research in Geneva, Switzerland. Its aim was to develop a method that could assist priority setting in health research investments. The first version of the CHNRI method was published in 2007–2008. The aim of this paper was to summarize the history of the development of the CHNRI method and its key conceptual advances. Methods The guiding principle of the CHNRI method is to expose the potential of many competing health research ideas to reduce disease burden and inequities that exist in the population in a feasible and cost–effective way. Results The CHNRI method introduced three key conceptual advances that led to its increased popularity in comparison to other priority–setting methods and processes. First, it proposed a systematic approach to listing a large number of possible research ideas, using the “4D” framework (description, delivery, development and discovery research) and a well–defined “depth” of proposed research ideas (research instruments, avenues, options and questions). Second, it proposed a systematic approach for discriminating between many proposed research ideas based on a well–defined context and criteria. The five “standard” components of the context are the population of interest, the disease burden of interest, geographic limits, time scale and the preferred style of investing with respect to risk. The five “standard” criteria proposed for prioritization between research ideas are answerability, effectiveness, deliverability, maximum potential for disease burden reduction and the effect on equity. However, both the context and the criteria can be flexibly changed to meet the specific needs of each priority–setting exercise. Third, it facilitated consensus development through measuring collective optimism on each component of each research idea among a larger group of experts using a simple

  12. Conceptual design study of advanced acoustic composite nacelle. [for achieving reductions in community noise and operating expense

    NASA Technical Reports Server (NTRS)

    Goodall, R. G.; Painter, G. W.

    1975-01-01

    Conceptual nacelle designs for wide-bodied and for advanced-technology transports were studied with the objective of achieving significant reductions in community noise with minimum penalties in airplane weight, cost, and in operating expense by the application of advanced composite materials to nacelle structure and sound suppression elements. Nacelle concepts using advanced liners, annular splitters, radial splitters, translating centerbody inlets, and mixed-flow nozzles were evaluated and a preferred concept selected. A preliminary design study of the selected concept, a mixed flow nacelle with extended inlet and no splitters, was conducted and the effects on noise, direct operating cost, and return on investment determined.

  13. Physical activity for people with a disability: a conceptual model.

    PubMed

    van der Ploeg, Hidde P; van der Beek, Allard J; van der Woude, Luc H V; van Mechelen, Willem

    2004-01-01

    The promotion of a physically active lifestyle has become an important issue in health policy in first-world countries. A physically active lifestyle is accompanied by several fitness and health benefits. Individuals with a disability can particularly benefit from an active lifestyle: not only does it reduce the risk for secondary health problems, but all levels of functioning can be influenced positively. The objective of this article is to propose a conceptual model that describes the relationships between physical activity behaviour, its determinants and functioning of people with a disability. The literature was systematically searched for articles considering physical activity and disability, and models relating both topics were looked for in particular. No models were found relating physical activity behaviour, its determinants and functioning in people with a disability. Consequently, a new model, the Physical Activity for people with a Disability (PAD) model, was constructed based on existing models of disability and models of determinants of physical activity behaviour. The starting point was the new WHO Model of Functioning and Disability, part of the International Classification of Functioning, Disability and Health (ICF), which describes the multidimensional aspects of functioning and disability. Physical activity behaviour and its determinants were integrated into the ICF model. The factors determining physical activity were based mainly on those used in the Attitude, Social influence and self-Efficacy (ASE) model. The proposed model can be used as a theoretical framework for future interventions and research on physical activity promotion in the population of people with a disability. The model currently forms the theoretical basis for a large physical activity promotion trial in ten Dutch rehabilitation centres.

  14. Conceptual geoinformation model of natural hazards risk assessment

    NASA Astrophysics Data System (ADS)

    Kulygin, Valerii

    2016-04-01

    Natural hazards are the major threat to safe interactions between nature and society. The assessment of the natural hazards impacts and their consequences is important in spatial planning and resource management. Today there is a challenge to advance our understanding of how socio-economical and climate changes will affect the frequency and magnitude of hydro-meteorological hazards and associated risks. However, the impacts from different types of natural hazards on various marine and coastal economic activities are not of the same type. In this study, the conceptual geomodel of risk assessment is presented to highlight the differentiation by the type of economic activities in extreme events risk assessment. The marine and coastal ecosystems are considered as the objects of management, on the one hand, and as the place of natural hazards' origin, on the other hand. One of the key elements in describing of such systems is the spatial characterization of their components. Assessment of ecosystem state is based on ecosystem indicators (indexes). They are used to identify the changes in time. The scenario approach is utilized to account for the spatio-temporal dynamics and uncertainty factors. Two types of scenarios are considered: scenarios of using ecosystem services by economic activities and scenarios of extreme events and related hazards. The reported study was funded by RFBR, according to the research project No. 16-35-60043 mol_a_dk.

  15. Further Conceptualization of Treatment Acceptability

    ERIC Educational Resources Information Center

    Carter, Stacy L.

    2008-01-01

    A review and extension of previous conceptualizations of treatment acceptability is provided in light of progress within the area of behavior treatment development and implementation. Factors including legislation, advances in research, and service delivery models are examined as to their relationship with a comprehensive conceptualization of…

  16. Advanced turbine systems program conceptual design and product development. Annual report, August 1993--July 1994

    SciTech Connect

    1994-11-01

    This Yearly Technical Progress Report covers the period August 3, 1993 through July 31, 1994 for Phase 2 of the Advanced Turbine Systems (ATS) Program by Solar Turbines Incorporated under DOE Contract No. DE-AC421-93MC30246. As allowed by the Contract (Part 3, Section J, Attachment B) this report is also intended to fulfill the requirements for a fourth quarterly report. The objective of Phase 2 of the ATS Program is to provide the conceptual design and product development plan for an ultra-high efficiency, environmentally superior and cost-competitive industrial gas turbine system to be commercialized in the year 2000. During the period covered by this report, Solar has completed three of eight program tasks and has submitted topical reports. These three tasks included a Project Plan submission of information required by NEPA, and the selection of a Gas-Fueled Advanced Turbine System (GFATS). In the latest of the three tasks, Solar`s Engineering team identified an intercooled and recuperated (ICR) gas turbine as the eventual outcome of DOE`s ATS program coupled with Solar`s internal New Product Introduction (NPI) program. This machine, designated ``ATS50`` will operate at a thermal efficiency (turbine shaft power/fuel LHV) of 50 percent, will emit less than 10 parts per million of NOx and will reduce the cost of electricity by 10 percent. It will also demonstrate levels of reliability, availability, maintainability, and durability (RAMD) equal to or better than those of today`s gas turbine systems. Current activity is concentrated in three of the remaining five tasks a Market Study, GFATS System Definition and Analysis, and the Design and Test of Critical Components.

  17. Biconic cargo return vehicle with an advanced recovery system. Volume 1: Conceptual design

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The conceptual design of the biconic Cargo Return Vehicle (CRV) is presented. The CRV will be able to meet all of the Space Station Freedom (SSF's) resupply needs. Worth note is the absence of a backup recovery chute in case of Advanced Recovery System (ARS) failure. The high reliability of ram-air parachutes does not warrant the penalty weight that such a system would create on successful missions. The CRV will launch vertically integrated with an Liquid Rocket Booster (LRB) vehicle and meets all NASA restrictions on fuel type for all phases of the mission. Because of the downscaled Orbital Maneuvering Vehicle (OMV) program, the CRV has been designed to be able to transfer cargo by docking directly to the Space Station Freedom as well as with OMV assistance. The CRV will cover enough crossrange to reach its primary landing site, Edwards Airforce Base, and all secondary landing sites with the exception of one orbit. Transportation back to KSC will be via the Boeing Super Guppy. Due to difficulties with man-rating the CRV, it will not be used in a CERV role. A brief summary of the CRV's specifications is given.

  18. Conceptual design study for an advanced cab and visual system, volume 1

    NASA Technical Reports Server (NTRS)

    Rue, R. J.; Cyrus, M. L.; Garnett, T. A.; Nachbor, J. W.; Seery, J. A.; Starr, R. L.

    1980-01-01

    A conceptual design study was conducted to define requirements for an advanced cab and visual system. The rotorcraft system integration simulator is for engineering studies in the area of mission associated vehicle handling qualities. Principally a technology survey and assessment of existing and proposed simulator visual display systems, image generation systems, modular cab designs, and simulator control station designs were performed and are discussed. State of the art survey data were used to synthesize a set of preliminary visual display system concepts of which five candidate display configurations were selected for further evaluation. Basic display concepts incorporated in these configurations included: real image projection, using either periscopes, fiber optic bundles, or scanned laser optics; and virtual imaging with helmet mounted displays. These display concepts were integrated in the study with a simulator cab concept employing a modular base for aircraft controls, crew seating, and instrumentation (or other) displays. A simple concept to induce vibration in the various modules was developed and is described. Results of evaluations and trade offs related to the candidate system concepts are given, along with a suggested weighting scheme for numerically comparing visual system performance characteristics.

  19. Conceptual Design of Front Ends for the Advanced Photon Source Multi-bend Achromats Upgrade

    SciTech Connect

    Jaski, Y.; Westferro, F.; Lee, S. H.; Yang, B.; Abliz, M.; Ramanathan, M.

    2016-07-27

    The proposed Advanced Photon Source (APS) upgrade from a double-bend achromats (DBA) to multi-bend achromats (MBA) lattice with ring energy change from 7 GeV to 6 GeV and beam current from 100 mA to 200 mA poses new challenges for front ends. All front ends must be upgraded to fulfill the following requirements: 1) handle the high heat load from two insertion devices in either inline or canted configuration, 2) include a clearing magnet in the front end to deflect and dump any electrons in case the electrons escape from the storage ring during swap-out injection with the safety shutters open, 3) incorporate the next generation x-ray beam position monitors (XBPMs) into the front end to meet the new stringent beam stability requirements. This paper presents the evaluation of the existing APS front ends and standardizes the insertion device (ID) front ends into two types: one for the single beam and one for the canted beams. The conceptual design of high heat load front end (HHLFE) and canted undulator front end (CUFE) for APS MBA upgrade is presented.

  20. Rule based design of conceptual models for formative evaluation

    NASA Technical Reports Server (NTRS)

    Moore, Loretta A.; Chang, Kai; Hale, Joseph P.; Bester, Terri; Rix, Thomas; Wang, Yaowen

    1994-01-01

    A Human-Computer Interface (HCI) Prototyping Environment with embedded evaluation capability has been investigated. This environment will be valuable in developing and refining HCI standards and evaluating program/project interface development, especially Space Station Freedom on-board displays for payload operations. This environment, which allows for rapid prototyping and evaluation of graphical interfaces, includes the following four components: (1) a HCI development tool; (2) a low fidelity simulator development tool; (3) a dynamic, interactive interface between the HCI and the simulator; and (4) an embedded evaluator that evaluates the adequacy of a HCI based on a user's performance. The embedded evaluation tool collects data while the user is interacting with the system and evaluates the adequacy of an interface based on a user's performance. This paper describes the design of conceptual models for the embedded evaluation system using a rule-based approach.

  1. On faculty incivility in nursing education: a conceptual model.

    PubMed

    Clark, Cynthia M

    2008-01-01

    Colaizzi's phenomenological method for qualitative study was used to describe nursing students' lived experiences with uncivil encounters with nursing faculty. Seven current and former nursing students from various levels of nursing education were interviewed to investigate their perceptions of faculty incivility in nursing education and to examine the emotional and behavioral impact the perceived incivility had on them. Three major themes emerged regarding faculty incivility: 1) behaving in demeaning and belittling ways, 2) treating students unfairly and subjectively, and 3) pressuring students to conform to unreasonable faculty demands. Three major themes emerged from students' emotional responses to faculty incivility: 1) feeling traumatized, 2) feeling powerless and helpless, and 3) feeling angry and upset. Behavioral responses are also reported. A conceptual model is presented to illustrate the findings. Recommendations for further research are included.

  2. Rule based design of conceptual models for formative evaluation

    NASA Technical Reports Server (NTRS)

    Moore, Loretta A.; Chang, Kai; Hale, Joseph P.; Bester, Terri; Rix, Thomas; Wang, Yaowen

    1994-01-01

    A Human-Computer Interface (HCI) Prototyping Environment with embedded evaluation capability has been investigated. This environment will be valuable in developing and refining HCI standards and evaluating program/project interface development, especially Space Station Freedom on-board displays for payload operations. This environment, which allows for rapid prototyping and evaluation of graphical interfaces, includes the following four components: (1) a HCI development tool, (2) a low fidelity simulator development tool, (3) a dynamic, interactive interface between the HCI and the simulator, and (4) an embedded evaluator that evaluates the adequacy of a HCI based on a user's performance. The embedded evaluation tool collects data while the user is interacting with the system and evaluates the adequacy of an interface based on a user's performance. This paper describes the design of conceptual models for the embedded evaluation system using a rule-based approach.

  3. Professional excellence and career advancement in nursing: a conceptual framework for clinical leadership development.

    PubMed

    Adeniran, Rita Kudirat; Bhattacharya, Anand; Adeniran, Anthony A

    2012-01-01

    Increasingly, stakeholders in the health care community are recognizing nursing as key to solving the nation's health care issues. This acknowledgment provides a unique opportunity for nursing to demonstrate leadership by developing clinical nurse leaders to collaborate with the multidisciplinary care team in driving evidence-based, safe quality, cost-effective health care services. One approach for nursing success is standardizing the entry-level education for nurses and developing a uniform professional development and career advancement trajectory with appropriate incentives to encourage participation. A framework to guide and provide scientific evidence of how frontline nurses can be engaged will be paramount. The model for professional excellence and career advancement provides a framework that offers a clear path for researchers to examine variables influencing nurses' professional development and career advancement in a systematic manner. Professional Excellence and Career Advancement in Nursing underscores professional preparedness of a registered nurse as central to leadership development. It also describes the elements that influence nurses' participation in professional development and career advancement under 4 main categories emphasizing mentorship and self-efficacy as essential variables.

  4. Modelling in Primary School: Constructing Conceptual Models and Making Sense of Fractions

    ERIC Educational Resources Information Center

    Shahbari, Juhaina Awawdeh; Peled, Irit

    2017-01-01

    This article describes sixth-grade students' engagement in two model-eliciting activities offering students the opportunity to construct mathematical models. The findings show that students utilized their knowledge of fractions including conceptual and procedural knowledge in constructing mathematical models for the given situations. Some students…

  5. Conceptual models of the evolution of transgressive dune field systems

    NASA Astrophysics Data System (ADS)

    Hesp, Patrick A.

    2013-10-01

    This paper examines the evolutionary paths of some transgressive dune fields that have formed on different coasts of the world, and presents some initial conceptual models of system dynamics for transgressive dune sheets and dune fields. Various evolutionary pathways are conceptualized based on a visual examination of dune fields from around the world. On coasts with high sediment supply, dune sheets and dune fields tend to accumulate as large scale barrier systems with little colonization of vegetation in arid-hyper to arid climate regimes, and as multiple, active discrete phases of dune field and deflation plain couplets in temperate to tropical environments. Active dune fields tend to be singular entities on coasts with low to moderate sediment supply. Landscape complexity and vegetation richness and diversity increases as dune fields evolve from simple active sheets and dunes to single and multiple deflation plains and basins, precipitation ridges, nebkha fields and a host of other dune types associated with vegetation (e.g. trailing ridges, slacks, remnant knobs, gegenwalle ridges and dune track ridges, 'tree islands' and 'bush pockets'). Three principal scenarios of transgressive dune sheet and dune field development are discussed, including dune sheets or dune fields evolving directly from the backshore, development following foredune and/or dune field erosion, and development from the breakdown or merging of parabolic dunes. Various stages of evolution are outlined for each scenario. Knowledge of evolutionary patterns and stages in coastal dune fields is very limited and caution is urged in attempts to reverse, change and/or modify dune fields to 'restore' some perceived loss of ecosystem or dune functioning.

  6. Conceptual models of the evolution of transgressive dune field systems

    NASA Astrophysics Data System (ADS)

    A. Hesp, Patrick

    2013-10-01

    This paper examines the evolutionary paths of some transgressive dune fields that have formed on different coasts of the world, and presents some initial conceptual models of system dynamics for transgressive dune sheets and dune fields. Various evolutionary pathways are conceptualized based on a visual examination of dune fields from around the world. On coasts with high sediment supply, dune sheets and dune fields tend to accumulate as large scale barrier systems with little colonization of vegetation in arid-hyper to arid climate regimes, and as multiple, active discrete phases of dune field and deflation plain couplets in temperate to tropical environments. Active dune fields tend to be singular entities on coasts with low to moderate sediment supply. Landscape complexity and vegetation richness and diversity increases as dune fields evolve from simple active sheets and dunes to single and multiple deflation plains and basins, precipitation ridges, nebkha fields and a host of other dune types associated with vegetation (e.g. trailing ridges, slacks, remnant knobs, gegenwalle ridges and dune track ridges, ‘tree islands' and ‘bush pockets'). Three principal scenarios of transgressive dune sheet and dune field development are discussed, including dune sheets or dune fields evolving directly from the backshore, development following foredune and/or dune field erosion, and development from the breakdown or merging of parabolic dunes. Various stages of evolution are outlined for each scenario. Knowledge of evolutionary patterns and stages in coastal dune fields is very limited and caution is urged in attempts to reverse, change and/or modify dune fields to ‘restore' some perceived loss of ecosystem or dune functioning.

  7. GIS-based Conceptual Database Model for Planetary Geoscientific Mapping

    NASA Astrophysics Data System (ADS)

    van Gasselt, Stephan; Nass, Andrea; Neukum, Gerhard

    2010-05-01

    We here report on the conceptual design of a geodatabase model as part of a larger-scaled GIS-based system composed of several applications, templates and database backend which supports conducting combined geological as well as geomorphological mapping of planetary surfaces and which simplifies the process of maintaining data and map products. Performing geological and/or geomorphological stand-alone or systematic mapping of planetary surfaces supported by modern GIS environments involves several tasks to be performed before the actual mapping process can be carried out. Such tasks deal with setting up a working environment by querying and defining raster data from a variety of planetary missions to be used and processed, importing auxiliary data, defining projection parameters for one or more map layer(s) and each raster/vector dataset, importing processed data, and defining a variety of vector shape geometries and attributes for mapping in terms of geometry type, representation symbology and attribute domains in a consistent way. In order to allow consistent mapping approaches and subsequent homogenisation success, a mapper makes use of pre-defined model schemas (templates) and definitions allowing to import mapping representation and styles as well as a backbone geo-database to immediately start working and making use of the provided infrastructure. The conceptual geo-database design developed far involves the design of the main object and data layers and consists of objects, object types, their relationships and additionally the formulation of integrity conditions on a level which is in principle independent of the exact implementation and its environment. Furthermore, the data layer containing attribute domains has been implemented. The conceptual design has been crafted using ESRI's ArcGIS File Geodatabase environment but it can be exported to any other GDBMS. The overall layout consists of several main elements or entity groups composed of relations

  8. A Conceptual Model For Effluent-Dependent Riverine Environments

    NASA Astrophysics Data System (ADS)

    Murphy, M. T.; Meyerhoff, R. D.; Osterkamp, W. R.; Smith, E. L.; Hawkins, R. H.

    2001-12-01

    The Arid West Water Quality Research Project (WQRP) is a multi-year, EPA-funded scientific endeavor directed by the Pima County, Wastewater Management Department in southern Arizona and focussed upon several interconnected ecological questions. These questions are crucial to water quality management in the arid and semi arid western US. A key component has been the ecological, hydrological and geomorphological investigation of habitat created by the discharge of treated effluent into ephemeral streams. Such environments are fundamentally different from the dry streams or rivers they displace; however, they are clearly not the perennial streams they superficially resemble. Under Arizona State regulations, such streams can bear the use designation of "Effluent Dependent Waters," or EDWs. Before this investigation, a hydrological/ecological conceptual model for these unique ecosystems had not been published. We have constructed one for general review that is designed to direct future work in the WQRP. The project investigated ten representative, yet contrasting EDW sites distributed throughout arid areas of the western US, to gather both historical and reconnaissance level field data, including in-stream and riparian, habitat and morphometric fluvial data. In most cases, the cross sectional area of the prior channel is oversized relative to the discharge of the introduced effluent. Where bed control is absent, the channels are incised downstream of the discharge point, further suggesting a disequilibrium between the channel and the regulated effluent flow. Several of the studied stream systems primarily convey storm water and are aggradational, exhibiting braided or anastomizing channels, high energy bedforms, and spatially dynamic interfluves. Active channels are formed in response to individual storm events and can be highly dynamic in both location and cross-sectional morphology. This poses a geomorphological challenge in the selection of a discharge point. We

  9. Postaudit evaluation of conceptual model uncertainty for a glacial aquifer groundwater flow and contaminant transport model

    NASA Astrophysics Data System (ADS)

    Lemke, Lawrence D.; Cypher, Joseph A.

    2010-06-01

    Numerical groundwater flow and contaminant transport modeling incorporating three alternative conceptual models was conducted in 2005 to assess remedial actions and predict contaminant concentrations in an unconfined glacial aquifer located in Milford, Michigan, USA. Three alternative conceptual models were constructed and independently calibrated to evaluate uncertainty in the geometry of an aquitard underlying the aquifer and the extent to which infiltration from two manmade surface water bodies influenced the groundwater flow field. Contaminant transport for benzene, cis-DCE, and MTBE was modeled for a 5-year period that included a 2-year history match from July 2003 to May 2005 and predictions for a 3-year period ending in July 2008. A postaudit of model performance indicates that predictions for pumping wells, which integrated the transport signal across multiple model layers, were reliable but unable to differentiate between alternative conceptual model responses. In contrast, predictions for individual monitoring wells with limited screened intervals were less consistent, but held promise for evaluating alternative hydrogeologic models. Results of this study suggest that model conceptualization can have important practical implications for the delineation of contaminant transport pathways using monitoring wells, but may exert less influence on integrated predictions for pumping wells screened over multiple numerical model layers.

  10. A tritium permeation model for conceptual fusion reactor designs

    NASA Astrophysics Data System (ADS)

    Hanchar, D. R.; Kazimi, M. S.

    1983-02-01

    A transient tritium permeation model is developed based on a simplified conceptual DT-fueled fusion reactor design. The major design features described in the model are a solid breeder blanket, a low pressure purge gas in the blanket, and a high pressure helium primary coolant. Tritium inventory in the breeder is considered to be due to diffusive hold-up and solubility effects. It is assumed that diffusive hold-up is the dominant factor in order to separate the solution for the breeder tritium concentration. The model was applied to the STARFIRE-Interim Reference Design, whose system parameters yielded a breeder tritium inventory on the order of grams, based on an average pellet radius of 10-3 cm. The breeder pellets reach their steady-state tritium content in approximately 1.4×104 s from system start-up, assuming continuous full power operation. Both the steady-state breeder tritium concentration and the time to reach that steady-state are proportional to the pellet radius squared. Other candidate solid breeders were considered, and their effect on the blanket tritium inventory was noted. The addition of oxygen to the primary coolant loop was required in order to keep the tritium losses through the heat exchanger to within the design goal of 0.1 Ci/day.

  11. [Conceptual model of teasing and bullying in adolescents].

    PubMed

    Lien, Angela Shin-Yu; Dai, Yu-Tzu; Lee, Ya-Ling

    2013-08-01

    Teasing and bullying incident levels have increased markedly in recent years according to international news reports. School and community-level action to stop and prevent bullying is a key focus of government education policy worldwide. Teasing is a usual facet of social interaction among youth and is related to bullying behavior. Although teasing and bullying are significant concerns, references for relevant concept analysis are lacking in the nursing field. To facilitate early screening to identify high-risk bullies and help victims effectively stop bullying events, concept analysis is needed to clarify and distinguish between the two concepts of teasing and bullying. The aim of this study is to integrate relevant published literature to determine the reasons for and relationships between teasing and bullying. We chose obesity as an example to construct a teasing and bullying conceptual model for adolescents and used this model to explore the related factors and health impacts of obesity. We found that both teaser intent and recipient perceptions correlated with bullying behavior. Duration and severity may induce teasing to become bullying. Because weight-based teasing is common among adolescents, we chose obesity as an example issue to demonstrate our adolescents teasing and bullying concept model. We then integrated the antecedent and consequential factors of teasing and bullying for obese adolescents. Weight-control strategies can stop school bullying if early interventions are performed in high-risk populations.

  12. Recent advances in atomic modeling

    SciTech Connect

    Goldstein, W.H.

    1988-10-12

    Precision spectroscopy of solar plasmas has historically been the goad for advances in calculating the atomic physics and dynamics of highly ionized atoms. Recent efforts to understand the laboratory plasmas associated with magnetic and inertial confinement fusion, and with X-ray laser research, have played a similar role. Developments spurred by laboratory plasma research are applicable to the modeling of high-resolution spectra from both solar and cosmic X-ray sources, such as the photoionized plasmas associated with accretion disks. Three of these developments in large scale atomic modeling are reviewed: a new method for calculating large arrays of collisional excitation rates, a sum rule based method for extending collisional-radiative models and modeling the effects of autoionizing resonances, and a detailed level accounting calculation of resonant excitation rates in FeXVII. 21 refs., 5 figs., 2 tabs.

  13. 7-GeV advanced photon source beamline initiative: Conceptual design report

    SciTech Connect

    Not Available

    1993-05-01

    The DOE is building a new generation 6-7 GeV Synchrotron Radiation Source known as the Advanced Photon Source (APS) at Argonne National Laboratory. This facility, to be completed in FY 1996, can provide 70 x-ray sources of unprecedented brightness to meet the research needs of virtually all scientific disciplines and numerous technologies. The technological research capability of the APS in the areas of energy, communications and health will enable a new partnership between the DOE and US industry. Current funding for the APS will complete the current phase of construction so that scientists can begin their applications in FY 1996. Comprehensive utilization of the unique properties of APS beams will enable cutting-edge research not currently possible. It is now appropriate to plan to construct additional radiation sources and beamline standard components to meet the excess demands of the APS users. In this APS Beamline Initiative, 2.5-m-long insertion-device x-ray sources will be built on four straight sections of the APS storage ring, and an additional four bending-magnet sources will also be put in use. The front ends for these eight x-ray sources will be built to contain and safeguard access to these bright x-ray beams. In addition, funds will be provided to build standard beamline components to meet scientific and technological research demands of the Collaborative Access Teams. The Conceptual Design Report (CDR) for the APS Beamline Initiative describes the scope of all the above technical and conventional construction and provides a detailed cost and schedule for these activities. The document also describes the preconstruction R&D plans for the Beamline Initiative activities and provides the cost estimates for the required R&D.

  14. Towards methodical modelling: Differences between the structure and output dynamics of multiple conceptual models

    NASA Astrophysics Data System (ADS)

    Knoben, Wouter; Woods, Ross; Freer, Jim

    2016-04-01

    Conceptual hydrologic models consist of a certain arrangement of spatial and temporal dynamics consisting of stores, fluxes and transformation functions, depending on the modeller's choices and intended use. They have the advantages of being computationally efficient, being relatively easy model structures to reconfigure and having relatively low input data demands. This makes them well-suited for large-scale and large-sample hydrology, where appropriately representing the dominant hydrologic functions of a catchment is a main concern. Given these requirements, the number of parameters in the model cannot be too high, to avoid equifinality and identifiability issues. This limits the number and level of complexity of dominant hydrologic processes the model can represent. Specific purposes and places thus require a specific model and this has led to an abundance of conceptual hydrologic models. No structured overview of these models exists and there is no clear method to select appropriate model structures for different catchments. This study is a first step towards creating an overview of the elements that make up conceptual models, which may later assist a modeller in finding an appropriate model structure for a given catchment. To this end, this study brings together over 30 past and present conceptual models. The reviewed model structures are simply different configurations of three basic model elements (stores, fluxes and transformation functions), depending on the hydrologic processes the models are intended to represent. Differences also exist in the inner workings of the stores, fluxes and transformations, i.e. the mathematical formulations that describe each model element's intended behaviour. We investigate the hypothesis that different model structures can produce similar behavioural simulations. This can clarify the overview of model elements by grouping elements which are similar, which can improve model structure selection.

  15. Computational Plume Modeling of COnceptual ARES Vehicle Stage Tests

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel C.; Ahuja, Vineet

    2007-01-01

    The plume-induced environment of a conceptual ARES V vehicle stage test at the NASA Stennis Space Center (NASA-SSC) was modeled using computational fluid dynamics (CFD). A full-scale multi-element grid was generated for the NASA-SSC B-2 test stand with the ARES V stage being located in a proposed off-center forward position. The plume produced by the ARES V main power plant (cluster of five RS-68 LOX/LH2 engines) was simulated using a multi-element flow solver - CRUNCH. The primary objective of this work was to obtain a fundamental understanding of the ARES V plume and its impingement characteristics on the B-2 flame-deflector. The location, size and shape of the impingement region were quantified along with the un-cooled deflector wall pressures, temperatures and incident heating rates. Issues with the proposed tests were identified and several of these addressed using the CFD methodology. The final results of this modeling effort will provide useful data and boundary conditions in upcoming engineering studies that are directed towards determining the required facility modifications for ensuring safe and reliable stage testing in support of the Constellation Program.

  16. Spiritual Healing in the Aftermath of Childhood Maltreatment: Translating Men's Lived Experiences Utilizing Nursing Conceptual Models and Theory.

    PubMed

    Willis, Danny G; DeSanto-Madeya, Susan; Ross, Richard; Sheehan, Danielle Leone; Fawcett, Jacqueline

    2015-01-01

    This article presents an explication of spiritual healing situated within 3 nursing conceptual models (Neuman's systems model, Rogers' science of unitary human beings, and Roy's adaptation model) and 1 middle-range theory (Watson's theory of human caring), all of which include a focus on spirituality. These models and the theory are the vehicle for translation of themes of spiritual healing extracted from data provided by 30 adult male survivors of childhood maltreatment into nursing practice. This discipline-specific translational scholarship advances the profession of nursing.

  17. Educational Criteria for Evaluating Simple Class Diagrams Made by Novices for Conceptual Modeling

    ERIC Educational Resources Information Center

    Kayama, Mizue; Ogata, Shinpei; Asano, David K.; Hashimoto, Masami

    2016-01-01

    Conceptual modeling is one of the most important learning topics for higher education and secondary education. The goal of conceptual modeling in this research is to draw a class diagram using given notation to satisfy the given requirements. In this case, the subjects are asked to choose concepts to satisfy the given requirements and to correctly…

  18. Semantic Description of Educational Adaptive Hypermedia Based on a Conceptual Model

    ERIC Educational Resources Information Center

    Papasalouros, Andreas; Retalis, Symeon; Papaspyrou, Nikolaos

    2004-01-01

    The role of conceptual modeling in Educational Adaptive Hypermedia Applications (EAHA) is especially important. A conceptual model of an educational application depicts the instructional solution that is implemented, containing information about concepts that must be ac-quired by learners, tasks in which learners must be involved and resources…

  19. The Value of Conceptual Models in Coping with Complexity and Interdisciplinarity in Environmental Sciences Education

    ERIC Educational Resources Information Center

    Fortuin, Karen P. J.; van Koppen, C. S. A.; Leemans, Rik

    2011-01-01

    Conceptual models are useful for facing the challenges of environmental sciences curriculum and course developers and students. These challenges are inherent to the interdisciplinary and problem-oriented character of environmental sciences curricula. In this article, we review the merits of conceptual models in facing these challenges. These…

  20. Teacher Emotion Research: Introducing a Conceptual Model to Guide Future Research

    ERIC Educational Resources Information Center

    Fried, Leanne; Mansfield, Caroline; Dobozy, Eva

    2015-01-01

    This article reports on the development of a conceptual model of teacher emotion through a review of teacher emotion research published between 2003 and 2013. By examining 82 publications regarding teacher emotion, the main aim of the review was to identify how teacher emotion was conceptualised in the literature and develop a conceptual model to…

  1. Advanced Modeling of Micromirror Devices

    NASA Technical Reports Server (NTRS)

    Michalicek, M. Adrian; Sene, Darren E.; Bright, Victor M.

    1995-01-01

    The flexure-beam micromirror device (FBMD) is a phase only piston style spatial light modulator demonstrating properties which can be used for phase adaptive corrective optics. This paper presents a complete study of a square FBMD, from advanced model development through final device testing and model verification. The model relates the electrical and mechanical properties of the device by equating the electrostatic force of a parallel-plate capacitor with the counter-acting spring force of the device's support flexures. The capacitor solution is derived via the Schwartz-Christoffel transformation such that the final solution accounts for non-ideal electric fields. The complete model describes the behavior of any piston-style device, given its design geometry and material properties. It includes operational parameters such as drive frequency and temperature, as well as fringing effects, mirror surface deformations, and cross-talk from neighboring devices. The steps taken to develop this model can be applied to other micromirrors, such as the cantilever and torsion-beam designs, to produce an advanced model for any given device. The micromirror devices studied in this paper were commercially fabricated in a surface micromachining process. A microscope-based laser interferometer is used to test the device in which a beam reflected from the device modulates a fixed reference beam. The mirror displacement is determined from the relative phase which generates a continuous set of data for each selected position on the mirror surface. Plots of this data describe the localized deflection as a function of drive voltage.

  2. A revised conceptual model of the tropical marine boundary layer

    NASA Astrophysics Data System (ADS)

    Davison, Jennifer L.

    on days with higher rain rates, and more (fewer) layers tended to be present when surface winds were more southerly (northerly). BSL statistics serve as the basis for a revised conceptual model of the TMBL, which contains 2-3 more layers of enhanced static stability, layered structure to the moisture variability and extends more than a km higher than the previous conceptual model. When compared, the distribution curves as functions of altitude for 1) BSL tops and 2) satellite derived cloud top heights had a correlation coefficient of 0.92, lending satellite support to the radar portrayal of the TMBL. Frequency by altitude diagrams (FADs) of rawinsonde data showed that the TMBL was sufficiently turbulent to support the Bragg scattering. RH gradients across 350 m intervals ranged from changes of greater than 95% to less than -60%, and all values of RH had a nearly equal probability of occurrence between 2 and 4 km. There were no preferred heights for temperature inversions, with inversions found across both 50 m and 350 m intervals for all altitudes above 1.2 km. The FAD of equivalent potential temperature indicated that the air modified by the ocean typically extended up to 4 km. Disturbed days (e.g., those with rain rates > 2 mm day-1) tended to be moister---with the moisture extending higher, than undisturbed days. The disturbed days also tended to be cooler between 2 and 4.5 km and have less northerly winds in the lowest 4 km.

  3. Development of Conceptual Benchmark Models to Evaluate Complex Hydrologic Model Calibration in Managed Basins Using Python

    NASA Astrophysics Data System (ADS)

    Hughes, J. D.; White, J.

    2013-12-01

    For many numerical hydrologic models it is a challenge to quantitatively demonstrate that complex models are preferable to simpler models. Typically, a decision is made to develop and calibrate a complex model at the beginning of a study. The value of selecting a complex model over simpler models is commonly inferred from use of a model with fewer simplifications of the governing equations because it can be time consuming to develop another numerical code with data processing and parameter estimation functionality. High-level programming languages like Python can greatly reduce the effort required to develop and calibrate simple models that can be used to quantitatively demonstrate the increased value of a complex model. We have developed and calibrated a spatially-distributed surface-water/groundwater flow model for managed basins in southeast Florida, USA, to (1) evaluate the effect of municipal groundwater pumpage on surface-water/groundwater exchange, (2) investigate how the study area will respond to sea-level rise, and (3) explore combinations of these forcing functions. To demonstrate the increased value of this complex model, we developed a two-parameter conceptual-benchmark-discharge model for each basin in the study area. The conceptual-benchmark-discharge model includes seasonal scaling and lag parameters and is driven by basin rainfall. The conceptual-benchmark-discharge models were developed in the Python programming language and used weekly rainfall data. Calibration was implemented with the Broyden-Fletcher-Goldfarb-Shanno method available in the Scientific Python (SciPy) library. Normalized benchmark efficiencies calculated using output from the complex model and the corresponding conceptual-benchmark-discharge model indicate that the complex model has more explanatory power than the simple model driven only by rainfall.

  4. Addressing Conceptual Model Uncertainty in the Evaluation of Model Prediction Errors

    NASA Astrophysics Data System (ADS)

    Carrera, J.; Pool, M.

    2014-12-01

    Model predictions are uncertain because of errors in model parameters, future forcing terms, and model concepts. The latter remain the largest and most difficult to assess source of uncertainty in long term model predictions. We first review existing methods to evaluate conceptual model uncertainty. We argue that they are highly sensitive to the ingenuity of the modeler, in the sense that they rely on the modeler's ability to propose alternative model concepts. Worse, we find that the standard practice of stochastic methods leads to poor, potentially biased and often too optimistic, estimation of actual model errors. This is bad news because stochastic methods are purported to properly represent uncertainty. We contend that the problem does not lie on the stochastic approach itself, but on the way it is applied. Specifically, stochastic inversion methodologies, which demand quantitative information, tend to ignore geological understanding, which is conceptually rich. We illustrate some of these problems with the application to Mar del Plata aquifer, where extensive data are available for nearly a century. Geologically based models, where spatial variability is handled through zonation, yield calibration fits similar to geostatiscally based models, but much better predictions. In fact, the appearance of the stochastic T fields is similar to the geologically based models only in areas with high density of data. We take this finding to illustrate the ability of stochastic models to accommodate many data, but also, ironically, their inability to address conceptual model uncertainty. In fact, stochastic model realizations tend to be too close to the "most likely" one (i.e., they do not really realize the full conceptualuncertainty). The second part of the presentation is devoted to argue that acknowledging model uncertainty may lead to qualitatively different decisions than just working with "most likely" model predictions. Therefore, efforts should concentrate on

  5. Establishing the Psychometric Properties of Constructs in a Community-Based Participatory Research Conceptual Model

    PubMed Central

    Oetzel, John; Zhou, Chuan; Duran, Bonnie; Pearson, Cynthia; Magarati, Maya; Lucero, Julie; Wallerstein, Nina; Villegas, Malia

    2016-01-01

    Purpose The purpose of this study is to establish the psychometric properties of 22 measures from a community-based participatory research (CBPR) conceptual model. Design On-line, cross-sectional survey of academic and community partners involved in a CPBR project Setting 294 CPBR projects in the U.S. with federal funding in 2009 Subjects 312 (77.2% of 404 invited) academic and community partners and 138 principal investigators/project directors (69.0% of 200 invited) Measures 22 measures of CBPR context, group dynamics, methods, and health-related outcomes Analysis Confirmatory factor analysis to establish factorial validity and Pearson correlations to establish convergent and divergent validity Results Confirmatory factor analysis demonstrated strong factorial validity for the 22 constructs. Pearson correlations (p < .001) supported the convergent and divergent validity of the measures. Internal consistency was strong with 18 of 22 measures achieving at least a .78 Cronbach’s alpha. Conclusion CBPR is a key approach for health promotion in underserved communities and/or communities of color and yet the basic psychometric properties of CBPR constructs have not been well established. This study provides evidence of the factorial, convergent, and discriminant validity, and internal consistency of 22 measures related to the CBPR conceptual model. Thus, these measures can be used with confidence by both CBPR practitioners and researchers to evaluate their own CBPR partnerships and advance the science of CBPR. PMID:24720389

  6. Advanced Mirror & Modelling Technology Development

    NASA Technical Reports Server (NTRS)

    Effinger, Michael; Stahl, H. Philip; Abplanalp, Laura; Maffett, Steven; Egerman, Robert; Eng, Ron; Arnold, William; Mosier, Gary; Blaurock, Carl

    2014-01-01

    The 2020 Decadal technology survey is starting in 2018. Technology on the shelf at that time will help guide selection to future low risk and low cost missions. The Advanced Mirror Technology Development (AMTD) team has identified development priorities based on science goals and engineering requirements for Ultraviolet Optical near-Infrared (UVOIR) missions in order to contribute to the selection process. One key development identified was lightweight mirror fabrication and testing. A monolithic, stacked, deep core mirror was fused and replicated twice to achieve the desired radius of curvature. It was subsequently successfully polished and tested. A recently awarded second phase to the AMTD project will develop larger mirrors to demonstrate the lateral scaling of the deep core mirror technology. Another key development was rapid modeling for the mirror. One model focused on generating optical and structural model results in minutes instead of months. Many variables could be accounted for regarding the core, face plate and back structure details. A portion of a spacecraft model was also developed. The spacecraft model incorporated direct integration to transform optical path difference to Point Spread Function (PSF) and between PSF to modulation transfer function. The second phase to the project will take the results of the rapid mirror modeler and integrate them into the rapid spacecraft modeler.

  7. Comparative analysis of conceptual models with error correction, artificial neural networks and committee models

    NASA Astrophysics Data System (ADS)

    Corzo P, Gerald A.; Solomatine, Dimitri

    2014-05-01

    In operational flow forecasting conceptual or process-based hydrological models are typically used, and more and more in combination with precipitation forecasts complemented by corrected data assimilation or data-driven error corrector models. Alternatively, predictive data-driven models, alone or in ensembles, have been employed in different researches, claiming that they ensure high accuracy of flow forecasting; for this, an artificial neural network (ANN) seems to be the most developed in studies. In this paper a comparative analysis of different error correctors and ANN models is made to contribute on the selection of operational. For this we explore the performance of various model combinations forecasting single and multiple time steps. The HBV hydrological model with and without error correction, data-driven models (ANNs) and hybrid committee models integrating conceptual models and ANNs. The capabilities of a model at a single time step (simulation) as well as multiple forecast horizons are represented in comparative graphs. Limitations of the meteorological forecasts are not contemplated in the hydrological forecast scenarios, so precipitation hindcast information was used as input in all models. Single time step forecast simulation of the HBV has 30 percent higher error than a one day forecast ANN model. However, for forecast horizons higher than 3 days a high variability of models' accuracy is found, and the clear dominant performance of the HBV hydrological model with an ANN error corrector is observed. In the forecasts for up to two days the committee and error-corrected models were the best, followed by ANN, and the conceptual model without error correction. The conceptual HBV model alone shows to perform best on long term sequential or iterative forecasts.

  8. How Iranian Women Conceptualize Mental Health: An Explanatory Model

    PubMed Central

    MIRABZADEH, Arash; FOROUZAN, Ameneh Setareh; MOHAMMADI, Farahnaz; DEJMAN, Masoumeh; BARADARAN EFTEKHARI, Monir

    2014-01-01

    Abstract Background In Iran, more than 25% of women suffer from mental disorders. Mental disorders and subclinical problems are associated with socioeconomic problem. At the community level, mental health promotion can reduce social damage. The aim of this study as a part of community based mental health promotion intervention was to explore how mental health in Iranian women is viewed. Methods According to a qualitative method in 2012, participants were selected by purposeful sampling from married women 18 to 65 years who are residents in Tehran. Fifteen in depth individual interviews were conducted with regard to the concept of mental health, causal pathway and help-seeking behavior according to explanatory model. Results Mental health was perceived as the same of emotional well-being. It conceptualized not only lack of mental disorder but also sense of satisfaction and healthy functioning. According to participant's view, the causal pathway of mental health problems were classified to individual, familial and social factors. Physical and behavioral problems were related to individual factor, Lack of marital adjustment was one of the most important issues in familial item and in social factor, cultural context and socio-economic problems were extracted. In help seeking process, all of the participants believed that the religion has important effect in mental health. Conclusion Marital adjustment is an important stage in process of mental health in women. PMID:25988094

  9. Modeling Tool Advances Rotorcraft Design

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Continuum Dynamics Inc. (CDI), founded in 1979, specializes in advanced engineering services, including fluid dynamic modeling and analysis for aeronautics research. The company has completed a number of SBIR research projects with NASA, including early rotorcraft work done through Langley Research Center, but more recently, out of Ames Research Center. NASA Small Business Innovation Research (SBIR) grants on helicopter wake modeling resulted in the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), a tool for studying helicopter and tiltrotor unsteady free wake modeling, including distributed and integrated loads, and performance prediction. Application of the software code in a blade redesign program for Carson Helicopters, of Perkasie, Pennsylvania, increased the payload and cruise speeds of its S-61 helicopter. Follow-on development resulted in a $24 million revenue increase for Sikorsky Aircraft Corporation, of Stratford, Connecticut, as part of the company's rotor design efforts. Now under continuous development for more than 25 years, CHARM models the complete aerodynamics and dynamics of rotorcraft in general flight conditions. CHARM has been used to model a broad spectrum of rotorcraft attributes, including performance, blade loading, blade-vortex interaction noise, air flow fields, and hub loads. The highly accurate software is currently in use by all major rotorcraft manufacturers, NASA, the U.S. Army, and the U.S. Navy.

  10. Initial Conceptualization and Application of the Alaska Thermokarst Model

    NASA Astrophysics Data System (ADS)

    Bolton, W. R.; Lara, M. J.; Genet, H.; Romanovsky, V. E.; McGuire, A. D.

    2015-12-01

    Thermokarst topography forms whenever ice-rich permafrost thaws and the ground subsides due to the volume loss when ground ice transitions to water. The Alaska Thermokarst Model (ATM) is a large-scale, state-and-transition model designed to simulate transitions between landscape units affected by thermokarst disturbance. The ATM uses a frame-based methodology to track transitions and proportion of cohorts within a 1-km2 grid cell. In the arctic tundra environment, the ATM tracks thermokarst-related transitions among wetland tundra, graminoid tundra, shrub tundra, and thermokarst lakes. In the boreal forest environment, the ATM tracks transitions among forested permafrost plateau, thermokarst lakes, collapse scar fens and bogs. The transition from one cohort to another due to thermokarst processes can take place if thaw reaches ice-rich ground layers either due to pulse disturbance (i.e. large precipitation event or fires), or due to gradual active layer deepening that eventually results in penetration of the protective layer. The protective layer buffers the ice-rich soils from the land surface and is critical to determine how susceptible an area is to thermokarst degradation. The rate of terrain transition in our model is determined by a set of rules that are based upon the ice-content of the soil, the drainage efficiency (or the ability of the landscape to store or transport water), the cumulative probability of thermokarst initiation, distance from rivers, lake dynamics (increasing, decreasing, or stable), and other factors. Tundra types are allowed to transition from one type to another (for example, wetland tundra to graminoid tundra) under favorable climatic conditions. In this study, we present our conceptualization and initial simulation results from in the arctic (the Barrow Peninsula) and boreal (the Tanana Flats) regions of Alaska.

  11. Health psychology as a context for massage therapy: a conceptual model with CAM as mediator.

    PubMed

    Hymel, Glenn M; Rich, Grant J

    2014-04-01

    Health psychology represents a context within which massage therapy research, education, and practice can be positioned for the mutual benefit of both. Furthermore, complementary and alternative medicine (CAM) more often than not plays a mediating role in relating massage therapy to health psychology. On occasion, though, the linkage between health psychology and massage therapy can be quite direct without the mediating influence of CAM. This paper, accordingly, advances a conceptual model via both flowchart and Venn diagram displays for viewing the health psychology context for massage therapy with the possibility of CAM as a mediating factor. Attention is also given to the broad range of issues constituting contemporary health psychology as well as its correspondence to an equally diverse array of client populations and health conditions addressed in massage therapy research. Future directions in the areas of health psychology, CAM, and massage therapy are proposed with a view toward a mutual and reciprocal benefit accruing to these behavioral and health science arenas.

  12. Using the conceptual site model approach to characterize groundwater quality

    SciTech Connect

    Shephard, E.; Glucksberg, N.; Walter, N.

    2007-07-01

    To understand groundwater quality, the first step is to develop a conceptual site model (CSM) that describes the site history, describes the geology and the hydrogeology of the site, identifies potential release areas or sources, and evaluates the fate and transport of site related compounds. After the physical site setting is understood and potential release areas are identified, appropriate and representative groundwater monitoring wells may be used to evaluate groundwater quality at a site and provide a network to assess impacts from potential future releases. To develop the CSM, the first step to understand the different requirements from each of the regulatory stakeholders. Each regulatory agency may have different approaches to site characterization and closure (i.e., different groundwater and soil remediation criteria). For example, the United States Environmental Protection Agency (EPA) and state governments have published guidance documents that proscribe the required steps and information needed to develop a CSM. The Nuclear Regulatory Commission (NRC) has a proscriptive model for the Historical Site Assessment under the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM), and contains requirements for developing a conceptual site model in NUREG 1757. Federal and state agencies may also have different closure criteria for potential contaminants of concern. Understanding these differences before starting a groundwater monitoring program is important because the minimum detectable activity (MDA), lowest limit detection (LLD), and sample quantitation limit (SQL) must be low enough so that data may be evaluated under each of the programs. After a Historical Site Assessment is completed a work plan is developed and executed to not only collect physical data that describes the geology and hydrogeology, but to also characterize the soil, groundwater, sediments, and surface water quality of each potentially impacted areas. Although the primary

  13. Conceptual Model of Water Resources in the Kabul Basin, Afghanistan

    USGS Publications Warehouse

    Mack, Thomas J.; Akbari, M. Amin; Ashoor, M. Hanif; Chornack, Michael P.; Coplen, Tyler B.; Emerson, Douglas G.; Hubbard, Bernard E.; Litke, David W.; Michel, Robert L.; Plummer, L. Niel; Rezai, M. Taher; Senay, Gabriel B.; Verdin, James P.; Verstraeten, Ingrid M.

    2010-01-01

    The United States (U.S.) Geological Survey has been working with the Afghanistan Geological Survey and the Afghanistan Ministry of Energy and Water on water-resources investigations in the Kabul Basin under an agreement supported by the United States Agency for International Development. This collaborative investigation compiled, to the extent possible in a war-stricken country, a varied hydrogeologic data set and developed limited data-collection networks to assist with the management of water resources in the Kabul Basin. This report presents the results of a multidisciplinary water-resources assessment conducted between 2005 and 2007 to address questions of future water availability for a growing population and of the potential effects of climate change. Most hydrologic and climatic data-collection activities in Afghanistan were interrupted in the early 1980s as a consequence of war and civil strife and did not resume until 2003 or later. Because of the gap of more than 20 years in the record of hydrologic and climatic observations, this investigation has made considerable use of remotely sensed data and, where available, historical records to investigate the water resources of the Kabul Basin. Specifically, this investigation integrated recently acquired remotely sensed data and satellite imagery, including glacier and climatic data; recent climate-change analyses; recent geologic investigations; analysis of streamflow data; groundwater-level analysis; surface-water- and groundwater-quality data, including data on chemical and isotopic environmental tracers; and estimates of public-supply and agricultural water uses. The data and analyses were integrated by using a simplified groundwater-flow model to test the conceptual model of the hydrologic system and to assess current (2007) and future (2057) water availability. Recharge in the basin is spatially and temporally variable and generally occurs near streams and irrigated areas in the late winter and early

  14. A Scoping Review: Conceptualizations and Pedagogical Models of Learning in Nursing Simulation

    ERIC Educational Resources Information Center

    Poikela, Paula; Teräs, Marianne

    2015-01-01

    Simulations have been implemented globally in nursing education for years with diverse conceptual foundations. The aim of this scoping review is to examine the literature regarding the conceptualizations of learning and pedagogical models in nursing simulations. A scoping review of peer-reviewed articles published between 2000 and 2013 was…

  15. Implementing Clickers to Assist Learning in Science Lectures: The Clicker-Assisted Conceptual Change Model

    ERIC Educational Resources Information Center

    Lin, Yi-Chun; Liu, Tzu-Chien; Chu, Ching-Chi

    2011-01-01

    The purposes of this study were twofold. The first aim was to design and develop a clicker-based instructional model known as "Clicker-Assisted Conceptual Change" (CACC), based on the cognitive conflict approach for conceptual change, to help students to learn scientific concepts. The second aim was to determine the beneficial effects of…

  16. Navigating Tensions between Conceptual and Metaconceptual Goals in the Use of Models

    ERIC Educational Resources Information Center

    Delgado, Cesar

    2015-01-01

    Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in "J Sci Educ Technol" 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build…

  17. A conceptual modeling framework for discrete event simulation using hierarchical control structures.

    PubMed

    Furian, N; O'Sullivan, M; Walker, C; Vössner, S; Neubacher, D

    2015-08-01

    Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM's applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models' system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example.

  18. Identifying Students' Mental Models of Sound Propagation: The Role of Conceptual Blending in Understanding Conceptual Change

    ERIC Educational Resources Information Center

    Hrepic, Zdeslav; Zollman, Dean A.; Rebello, N. Sanjay

    2010-01-01

    We investigated introductory physics students' mental models of sound propagation. We used a phenomenographic method to analyze the data in the study. In addition to the scientifically accepted Wave model, students used the "Entity" model to describe the propagation of sound. In this latter model sound is a self-standing entity,…

  19. Current theoretical models of generalized anxiety disorder (GAD): conceptual review and treatment implications.

    PubMed

    Behar, Evelyn; DiMarco, Ilyse Dobrow; Hekler, Eric B; Mohlman, Jan; Staples, Alison M

    2009-12-01

    Theoretical conceptualizations of generalized anxiety disorder (GAD) continue to undergo scrutiny and refinement. The current paper critiques five contemporary models of GAD: the Avoidance Model of Worry and GAD [Borkovec, T. D. (1994). The nature, functions, and origins of worry. In: G. Davey & F. Tallis (Eds.), Worrying: perspectives on theory assessment and treatment (pp. 5-33). Sussex, England: Wiley & Sons; Borkovec, T. D., Alcaine, O. M., & Behar, E. (2004). Avoidance theory of worry and generalized anxiety disorder. In: R. Heimberg, C. Turk, & D. Mennin (Eds.), Generalized anxiety disorder: advances in research and practice (pp. 77-108). New York, NY, US: Guilford Press]; the Intolerance of Uncertainty Model [Dugas, M. J., Letarte, H., Rheaume, J., Freeston, M. H., & Ladouceur, R. (1995). Worry and problem solving: evidence of a specific relationship. Cognitive Therapy and Research, 19, 109-120; Freeston, M. H., Rheaume, J., Letarte, H., Dugas, M. J., & Ladouceur, R. (1994). Why do people worry? Personality and Individual Differences, 17, 791-802]; the Metacognitive Model [Wells, A. (1995). Meta-cognition and worry: a cognitive model of generalized anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301-320]; the Emotion Dysregulation Model [Mennin, D. S., Heimberg, R. G., Turk, C. L., & Fresco, D. M. (2002). Applying an emotion regulation framework to integrative approaches to generalized anxiety disorder. Clinical Psychology: Science and Practice, 9, 85-90]; and the Acceptance-based Model of GAD [Roemer, L., & Orsillo, S. M. (2002). Expanding our conceptualization of and treatment for generalized anxiety disorder: integrating mindfulness/acceptance-based approaches with existing cognitive behavioral models. Clinical Psychology: Science and Practice, 9, 54-68]. Evidence in support of each model is critically reviewed, and each model's corresponding evidence-based therapeutic interventions are discussed. Generally speaking, the models share an

  20. Distributed hydrological models: comparison between TOPKAPI, a physically based model and TETIS, a conceptually based model

    NASA Astrophysics Data System (ADS)

    Ortiz, E.; Guna, V.

    2009-04-01

    The present work aims to carry out a comparison between two distributed hydrological models, the TOPKAPI (Ciarapica and Todini, 1998; Todini and Ciarapica, 2001) and TETIS (Vélez, J. J.; Vélez J. I. and Francés, F, 2002) models, obtaining the hydrological solution computed on the basis of the same storm events. The first model is physically based and the second one is conceptually based. The analysis was performed on the 21,4 km2 Goodwin Creek watershed, located in Panola County, Mississippi. This watershed extensively monitored by the Agricultural Research Service (ARS) National Sediment Laboratory (NSL) has been chosen because it offers a complete database compiling precipitation (16 rain gauges), runoff (6 discharge stations) and GIS data. Three storm events were chosen to evaluate the performance of the two models: the first one was chosen to calibrate the models, and the other two to validate them. Both models performed a satisfactory hydrological response both in calibration and validation events. While for the TOPKAPI model it wasn't a real calibration, due to its really good performance with parameters modal values derived of watershed characteristics, for the TETIS model it has been necessary to perform a previous automatic calibration. This calibration was carried out using the data provided by the observed hydrograph, in order to adjust the modeĺs 9 correction factors. Keywords: TETIS, TOPKAPI, distributed models, hydrological response, ungauged basins.

  1. A conceptual modeling framework for discrete event simulation using hierarchical control structures

    PubMed Central

    Furian, N.; O’Sullivan, M.; Walker, C.; Vössner, S.; Neubacher, D.

    2015-01-01

    Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM’s applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models’ system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example. PMID:26778940

  2. Assessment of hydrological model predictive ability given multiple conceptual geological models

    NASA Astrophysics Data System (ADS)

    Seifert, Dorte; Sonnenborg, Torben O.; Refsgaard, Jens Christian; HøJberg, Anker L.; Troldborg, Lars

    2012-06-01

    In this study six hydrological models that only differ with respect to their conceptual geological models are established for a 465 km2 area. The performances of the six models are evaluated in differential split-sample tests against a unique data set with well documented groundwater head and discharge data for different periods with different groundwater abstractions. The calibration results of the six models are comparable, with no model being superior to the others. Though, the six models make very different predictions of changes in groundwater head and discharges as a response to changes in groundwater abstraction. This confirms the utmost importance of the conceptual geological model for making predictions of variables and conditions beyond the calibration situation. In most cases the observed changes in hydraulic head and discharge are within the range of the changes predicted by the six models implying that a multiple modeling approach can be useful in obtaining more robust assessments of likely prediction errors. We conclude that the use of multiple models appear to be a good alternative to traditional differential split-sample schemes. A model averaging analysis shows that model weights estimated from model performance in the calibration or validation situation in many cases are not optimal for making other predictions. Hence, the critical assumption that is always made in model averaging, namely that the model weights derived from the calibration situation are also optimal for model predictions, cannot be assumed to be generally valid.

  3. A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek

    2007-01-01

    A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

  4. Detailed heat load calculations at the beginning, middle, and end of cycle for the conceptual design of the Advanced Neutron Source Reactor

    SciTech Connect

    Wemple, C. A.; Schnitzler, B. G.

    1995-04-01

    The Advanced Neutron Source (ANS) is a world-class research reactor and experimental center for neutron research, presently being designed at the Oak Ridge National Laboratory (ORNL). The reactor consists of a 330-MW(f) highly enriched uranium core, which is cooled, moderated, and reflected with heavy water. When completed, it will be the preeminent ultrahigh neutron flux reactor in the world, with facilities for research programs in biology, materials science, chemistry, fundamental and nuclear physics, and analytical chemistry. Irradiation facilities are provided for a variety of isotope production capabilities, as well as materials irradiation. The ANS reactor design, at the time of this report, has completed the conceptual design phase and entered the advanced conceptual design phase. This report is part of an effort to fully document the analysis methods and results for the conceptual design. It details the methods used to perform heat load calculations on the ANS reactor design, describes the model used, and gives the resulting heat loads in all components of the reactor, in both a differential (by segment) and integral (by component) fashion. These heat load data are provided at three times within the ANS fuel cycle - at beginning (0 days), middle (8.5 days), and end (17 days) of cycle. The remainder of the report is dedicated to this description. In Chapter 2, some necessary background on the reactor design is provided. Chapters 3 and 4 give details of the depletion methods used and revisions to previous MCNP models. Chapter 5 analyzes the results of these calculations, and Chapter 6 provides a summary and conclusions.

  5. Collective (Team) Learning Process Models: A Conceptual Review

    ERIC Educational Resources Information Center

    Knapp, Randall

    2010-01-01

    Teams have become a key resource for learning and accomplishing work in organizations. The development of collective learning in specific contexts is not well understood, yet has become critical to organizational success. The purpose of this conceptual review is to inform human resource development (HRD) practice about specific team behaviors and…

  6. Using Multilevel Modeling in Language Assessment Research: A Conceptual Introduction

    ERIC Educational Resources Information Center

    Barkaoui, Khaled

    2013-01-01

    This article critiques traditional single-level statistical approaches (e.g., multiple regression analysis) to examining relationships between language test scores and variables in the assessment setting. It highlights the conceptual, methodological, and statistical problems associated with these techniques in dealing with multilevel or nested…

  7. Psychological Mechanisms of Medically Unexplained Symptoms: An Integrative Conceptual Model

    ERIC Educational Resources Information Center

    Brown, Richard J.

    2004-01-01

    Theories of medically unexplained illness based on the concepts of dissociation, conversion, and somatization are summarized. Evidence cited in support of these theories is described and the conceptual strengths and shortcomings of each approach are considered. It is argued that each of these approaches adds to the understanding of unexplained…

  8. Adapting Conceptual Models for Cross-Cultural Applications

    ERIC Educational Resources Information Center

    Perleth, Christoph; Heller, Kurt A.

    2007-01-01

    It is of major importance to use psychological tests and questionnaires that are carefully constructed so that their reliability and validity can be determined in different (sub)cultures (Campbell & Tirri, 2004). However, a necessary prerequisite for this is the development of solid conceptual constructs. Otherwise, the researcher runs into the…

  9. Crowd Confrontation and Non-Lethal Weapons: A Literature Review and Conceptual Model

    DTIC Science & Technology

    2008-03-01

    Crowd Confrontation and Non-Lethal Weapons A literature review and conceptual model A. Frini L. Stemate S . Larochelle DRDC CORA G. Toussaint...Confrontation and Non-Lethal Weapons A literature review and conceptual model A. Frini L. Stemate S . Larochelle DRDC CORA G. Toussaint R. Lecocq...significant factors influencing the behaviour of individuals in a crowd. The model is proposed as a starting point for the future research efforts of

  10. Comparison of conceptual designs for 25 kWe advanced Stirling conversion systems for dish electric applications

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1989-01-01

    The Advanced Stirling Conversion System (ASCS) Project is managed by NASA Lewis Research Center through a cooperative interagency agreement with DOE. Conceptual designs for the ASCS's were completed under parallel contracts in 1987 by Mechanical Technology Inc. (MTI) of Latham, NY, and Stirling Technology Company (STC) of Richland, WA. Each design features a free-piston Stirling engine, a liquid metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting DOE's long term performance and cost goals. An independent assessment showed that both designs are manufacturable and have the potential to easily meet DOE's long term cost goals.

  11. Comparison of conceptual designs for 25 kWe advanced Stirling conversion systems for dish electric application

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.; Schreiber, Jeffrey G.

    1989-01-01

    The Advanced Stirling Conversion System (ASCS) Project is managed by NASA Lewis Research Center through a cooperative interagency agreement with DOE. Conceptual designs for the ASCS's were completed under parallel contracts in 1987 by Mechanical Technology Inc. (MTI) of Latham, NY, and Stirling Technology Company (STC) of Richland, WA. Each design features a free-piston Stirling engine, a liquid metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting DOE's long term performance and cost goals. An independent assessment showed that both designs are manufacturable and have the potential to easily meet DOE's long term cost goals.

  12. CONCEPTUAL DESIGN AND ECONOMICS OF THE ADVANCED CO2 HYBRID POWER CYCLE

    SciTech Connect

    A. Nehrozoglu

    2004-12-01

    Research has been conducted under United States Department of Energy Contract DEFC26-02NT41621 to analyze the feasibility of a new type of coal-fired plant for electric power generation. This new type of plant, called the Advanced CO{sub 2} Hybrid Power Plant, offers the promise of efficiencies nearing 36 percent, while concentrating CO{sub 2} for 100% sequestration. Other pollutants, such as SO{sub 2} and NOx, are sequestered along with the CO{sub 2} yielding a zero emissions coal plant. The CO{sub 2} Hybrid is a gas turbine-steam turbine combined cycle plant that uses CO{sub 2} as its working fluid to facilitate carbon sequestration. The key components of the plant are a cryogenic air separation unit (ASU), a pressurized circulating fluidized bed gasifier, a CO{sub 2} powered gas turbine, a circulating fluidized bed boiler, and a super-critical pressure steam turbine. The gasifier generates a syngas that fuels the gas turbine and a char residue that, together with coal, fuels a CFB boiler to power the supercritical pressure steam turbine. Both the gasifier and the CFB boiler use a mix of ASU oxygen and recycled boiler flue gas as their oxidant. The resulting CFB boiler flue gas is essentially a mixture of oxygen, carbon dioxide and water. Cooling the CFB flue gas to 80 deg. F condenses most of the moisture and leaves a CO{sub 2} rich stream containing 3%v oxygen. Approximately 30% of this flue gas stream is further cooled, dried, and compressed for pipeline transport to the sequestration site (the small amount of oxygen in this stream is released and recycled to the system when the CO{sub 2} is condensed after final compression and cooling). The remaining 70% of the flue gas stream is mixed with oxygen from the ASU and is ducted to the gas turbine compressor inlet. As a result, the gas turbine compresses a mixture of carbon dioxide (ca. 64%v) and oxygen (ca. 32.5%v) rather than air. This carbon dioxide rich mixture then becomes the gas turbine working fluid and

  13. Experimental Evidence of the Superiority of the Prevalence Model of Conceptual Change over the Classical Models and Repetition

    ERIC Educational Resources Information Center

    Potvin, Patrice; Sauriol, Érik; Riopel, Martin

    2015-01-01

    This quasi-experimental study investigated the effects on 558 grades five and six students of three different teaching conditions: the "classical" model of conceptual change (for which cognitive conflict is considered as a precondition to the transformation of knowledge), the "prevalence" model of conceptual change (in which…

  14. How to conceptualize catalytic cycles? The energetic span model.

    PubMed

    Kozuch, Sebastian; Shaik, Sason

    2011-02-15

    efficiency of a catalyst. Additionally, the TDI and TDTS are not necessarily the highest and lowest states, nor do they have to be adjoined as a single step. As such, we can conclude that a change in the conceptualization of catalytic cycles is in order: in catalysis, there are no rate-determining steps, but rather rate-determining states. We also include a study on the effect of reactant and product concentrations. In the energetic span approximation, only the reactants or products that are located between the TDI and TDTS accelerate or inhibit the reaction. In this manner, the energetic span model creates a direct link between experimental quantities and theoretical results. The versatility of the energetic span model is demonstrated with several catalytic cycles of organometallic reactions.

  15. Conceptual geologic model and native state model of the Roosevelt Hot Springs hydrothermal system

    SciTech Connect

    Faulder, D.D.

    1991-01-01

    A conceptual geologic model of the Roosevelt Hot Springs hydrothermal system was developed by a review of the available literature. The hydrothermal system consists of a meteoric recharge area in the Mineral Mountains, fluid circulation paths to depth, a heat source, and an outflow plume. A conceptual model based on the available data can be simulated in the native state using parameters that fall within observed ranges. The model temperatures, recharge rates, and fluid travel times are sensitive to the permeability in the Mineral Mountains. The simulation results suggests the presence of a magma chamber at depth as the likely heat source. A two-dimensional study of the hydrothermal system can be used to establish boundary conditions for further study of the geothermal reservoir.

  16. Validation of the Continuum of Care Conceptual Model for Athletic Therapy

    PubMed Central

    Lafave, Mark R.; Butterwick, Dale; Eubank, Breda

    2015-01-01

    Utilization of conceptual models in field-based emergency care currently borrows from existing standards of medical and paramedical professions. The purpose of this study was to develop and validate a comprehensive conceptual model that could account for injuries ranging from nonurgent to catastrophic events including events that do not follow traditional medical or prehospital care protocols. The conceptual model should represent the continuum of care from the time of initial injury spanning to an athlete's return to participation in their sport. Finally, the conceptual model should accommodate both novices and experts in the AT profession. This paper chronicles the content validation steps of the Continuum of Care Conceptual Model for Athletic Therapy (CCCM-AT). The stages of model development were domain and item generation, content expert validation using a three-stage modified Ebel procedure, and pilot testing. Only the final stage of the modified Ebel procedure reached a priori 80% consensus on three domains of interest: (1) heading descriptors; (2) the order of the model; (3) the conceptual model as a whole. Future research is required to test the use of the CCCM-AT in order to understand its efficacy in teaching and practice within the AT discipline. PMID:26464897

  17. A Study of Child Variance, Volume 1: Conceptual Models; Conceptual Project in Emotional Disturbance.

    ERIC Educational Resources Information Center

    Rhodes, William C.; Tracy, Michael L.

    Presented are 11 papers discussing the following six models of emotional disturbance in children: biophysical, behavioral, psychodynamic, sociological, and ecological, models, and counter theory. Emotional disturbance is defined as a distinctive human state having multiple manifestations and involving disability, deviance, and alienation. All the…

  18. Implications of Simulation Conceptual Model Development for Simulation Management and Uncertainty Assessment

    NASA Technical Reports Server (NTRS)

    Pace, Dale K.

    2000-01-01

    A simulation conceptual model is a simulation developers way of translating modeling requirements (i. e., what is to be represented by the simulation or its modification) into a detailed design framework (i. e., how it is to be done), from which the software, hardware, networks (in the case of distributed simulation), and systems/equipment that will make up the simulation can be built or modified. A conceptual model is the collection of information which describes a simulation developers concept about the simulation and its pieces. That information consists of assumptions, algorithms, characteristics, relationships, and data. Taken together, these describe how the simulation developer understands what is to be represented by the simulation (entities, actions, tasks, processes, interactions, etc.) and how that representation will satisfy the requirements to which the simulation responds. Thus the conceptual model is the basis for judgment about simulation fidelity and validity for any condition that is not specifically tested. The more perspicuous and precise the conceptual model, the more likely it is that the simulation development will both fully satisfy requirements and allow demonstration that the requirements are satisfied (i. e., validation). Methods used in simulation conceptual model development have significant implications for simulation management and for assessment of simulation uncertainty. This paper suggests how to develop and document a simulation conceptual model so that the simulation fidelity and validity can be most effectively determined. These ideas for conceptual model development apply to all simulation varieties. The paper relates these ideas to uncertainty assessments as they relate to simulation fidelity and validity. The paper also explores implications for simulation management from conceptual model development methods, especially relative to reuse of simulation components.

  19. Environmental Cleanup Best Management Practices: Effective Use of the Project Life Cycle Conceptual Site Model

    EPA Pesticide Factsheets

    This fact sheet is the first in a series of documents that address conceptual site models (CSMs). This fact sheet summarizes how environmental practitioners can use CSMs to achieve, communicate, and maintain stakeholder consensus.

  20. Guidance for the Development of Conceptual Models for a Problem Formulation Developed for Registration Review

    EPA Pesticide Factsheets

    Conceptual models for aquatic and terrestrial exposures. Graphic representation of predicted relationships between the ecological entities, both listed (threatened and endangered) and non-listed species, and the stressors to which they may be exposed.

  1. CONCEPTUAL MODELS AND THE CUBAN MISSILE CRISIS: RATIONAL POLICY, ORGANIZATION PROCESS, AND BUREAUCRATIC POLITICS

    DTIC Science & Technology

    This paper constitutes an abstract of a Ph.D. dissertation, ’Policy Process, and Politics: Conceptual Models and the Cuban Missile Crisis,’ accepted by the Department of Government, Harvard University , January, 1968.

  2. Triad Issue Paper: Using Geophysical Tools to Develop the Conceptual Site Model

    EPA Pesticide Factsheets

    This technology bulletin explains how hazardous-waste site professionals can use geophysical tools to provide information about subsurface conditions to create a more representative conceptual site model (CSM).

  3. Student perception and conceptual development as represented by student mental models of atomic structure

    NASA Astrophysics Data System (ADS)

    Park, Eun Jung

    The nature of matter based upon atomic theory is a principal concept in science; hence, how to teach and how to learn about atoms is an important subject for science education. To this end, this study explored student perceptions of atomic structure and how students learn about this concept by analyzing student mental models of atomic structure. Changes in student mental models serve as a valuable resource for comprehending student conceptual development. Data was collected from students who were taking the introductory chemistry course. Responses to course examinations, pre- and post-questionnaires, and pre- and post-interviews were used to analyze student mental models of atomic structure. First, this study reveals that conceptual development can be achieved, either by elevating mental models toward higher levels of understanding or by developing a single mental model. This study reinforces the importance of higher-order thinking skills to enable students to relate concepts in order to construct a target model of atomic structure. Second, Bohr's orbital structure seems to have had a strong influence on student perceptions of atomic structure. With regard to this finding, this study suggests that it is instructionally important to teach the concept of "orbitals" related to "quantum theory." Third, there were relatively few students who had developed understanding at the level of the target model, which required student understanding of the basic ideas of quantum theory. This study suggests that the understanding of atomic structure based on the idea of quantum theory is both important and difficult. Fourth, this study included different student assessments comprised of course examinations, questionnaires, and interviews. Each assessment can be used to gather information to map out student mental models. Fifth, in the comparison of the pre- and post-interview responses, this study showed that high achieving students moved toward more improved models or to advanced

  4. Developing a Conceptual Architecture for a Generalized Agent-based Modeling Environment (GAME)

    DTIC Science & Technology

    2008-03-01

    possible. A conceptual architecture for a generalized agent- based modeling environment (GAME) based upon design principles from OR/MS systems was created...conceptual architecture for a generalized agent-based modeling environment (GAME) based upon design principles from OR/MS systems was created that...handle the event, and subsequently form the relevant plans. One of these plans will be selected, and either pushed to the top of the current

  5. Advances in Watershed Models and Modeling

    NASA Astrophysics Data System (ADS)

    Yeh, G. T.; Zhang, F.

    2015-12-01

    The development of watershed models and their applications to real-world problems has evolved significantly since 1960's. Watershed models can be classified based on what media are included, what processes are dealt with, and what approaches are taken. In term of media, a watershed may include segregated overland regime, river-canal-open channel networks, ponds-reservoirs-small lakes, and subsurface media. It may also include integrated media of all these or a partial set of these as well as man-made control structures. In term of processes, a watershed model may deal with coupled or decoupled hydrological and biogeochemical cycles. These processes include fluid flow, thermal transport, salinity transport, sediment transport, reactive transport, and biota and microbe kinetics. In terms of approaches, either parametric or physics-based approach can be taken. This talk discusses the evolution of watershed models in the past sixty years. The advances of watershed models center around their increasing design capability to foster these segregated or integrated media and coupled or decoupled processes. Widely used models developed by academia, research institutes, government agencies, and private industries will be reviewed in terms of the media and processes included as well as approaches taken. Many types of potential benchmark problems in general can be proposed and will be discussed. This presentation will focus on three benchmark problems of biogeochemical cycles. These three problems, dealing with water quality transport, will be formulated in terms of reactive transport. Simulation results will be illustrated using WASH123D, a watershed model developed and continuously updated by the author and his PhD graduates. Keywords: Hydrological Cycles, Biogeochemical Cycles, Biota Kinetics, Parametric Approach, Physics-based Approach, Reactive Transport.

  6. Conceptual design study for an advanced cab and visual system, volume 2

    NASA Technical Reports Server (NTRS)

    Rue, R. J.; Cyrus, M. L.; Garnett, T. A.; Nachbor, J. W.; Seery, J. A.; Starr, R. L.

    1980-01-01

    The performance, design, construction and testing requirements are defined for developing an advanced cab and visual system. The rotorcraft system integration simulator is composed of the advanced cab and visual system and the rotorcraft system motion generator, and is part of an existing simulation facility. User's applications for the simulator include rotorcraft design development, product improvement, threat assessment, and accident investigation.

  7. Raft River Geothermal Area Data Models - Conceptual, Logical and Fact Models

    DOE Data Explorer

    Cuyler, David

    2012-07-19

    Conceptual and Logical Data Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses at Raft River a. Logical Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 b. Fact Model for Geothermal Data Concerning Wells, Fields, Power Plants and Related Analyses, David Cuyler 2010 Derived from Tables, Figures and other Content in Reports from the Raft River Geothermal Project: "Technical Report on the Raft River Geothermal Resource, Cassia County, Idaho," GeothermEx, Inc., August 2002. "Results from the Short-Term Well Testing Program at the Raft River Geothermal Field, Cassia County, Idaho," GeothermEx, Inc., October 2004.

  8. A Conceptual Model for Analysing Management Development in the UK Hospitality Industry

    ERIC Educational Resources Information Center

    Watson, Sandra

    2007-01-01

    This paper presents a conceptual, contingent model of management development. It explains the nature of the UK hospitality industry and its potential influence on MD practices, prior to exploring dimensions and relationships in the model. The embryonic model is presented as a model that can enhance our understanding of the complexities of the…

  9. A Confirmatory Structural Equation Model of Achievement Estimated by Dichotomous Attitudes, Interest, and Conceptual Understanding

    ERIC Educational Resources Information Center

    Kim, Minkee; Song, Jinwoong

    2010-01-01

    Many models in science education have tried to clarify the causal relationships of affective variables on student performance, by presenting theoretical models, exploratory SEM (structural equation models), and confirmatory SEM. Based on the literature, the recent AS-TI-CU model scrutinised the most robust stimuli of conceptual understanding (CU):…

  10. Requirements for the conceptual design of advanced underground coal extraction systems

    NASA Technical Reports Server (NTRS)

    Gangal, M. D.; Lavin, M. L.

    1981-01-01

    Conceptual design requirements are presented for underground coal mining systems having substantially improved performance in the areas of production cost and miner safety. Mandatory performance levels are also set for miner health, environmental impact, and coal recovery. In addition to mandatory design goals and constraints, a number of desirable system characteristics are identified which must be assessed in terms of their impact on production cost and their compatibility with other system elements. Although developed for the flat lying, moderately thick seams of Central Appalachia, these requirements are designed to be easily adaptable to other coals.

  11. Advanced turbine systems program conceptual design and product development. Quarterly report, August--October 1995

    SciTech Connect

    1996-01-01

    This report describes the tasks completed for the advanced turbine systems program. The topics of the report include last row turbine blade development, single crystal blade casting development, ceramic materials development, combustion cylinder flow mapping, shroud film cooling, directional solidified valve development, shrouded blade cooling, closed-loop steam cooling, active tip clearance control, flow visualization tests, combustion noise investigation, TBC field testing, catalytic combustion development, optical diagnostics probe development, serpentine channel cooling tests, brush seal development, high efficiency compressor design, advanced air sealing development, advanced coating development, single crystal blade development, Ni-based disc forging development, and steam cooling effects on materials.

  12. A Common Core for Active Conceptual Modeling for Learning from Surprises

    NASA Astrophysics Data System (ADS)

    Liddle, Stephen W.; Embley, David W.

    The new field of active conceptual modeling for learning from surprises (ACM-L) may be helpful in preserving life, protecting property, and improving quality of life. The conceptual modeling community has developed sound theory and practices for conceptual modeling that, if properly applied, could help analysts model and predict more accurately. In particular, we need to associate more semantics with links, and we need fully reified high-level objects and relationships that have a clear, formal underlying semantics that follows a natural, ontological approach. We also need to capture more dynamic aspects in our conceptual models to more accurately model complex, dynamic systems. These concepts already exist, and the theory is well developed; what remains is to link them with the ideas needed to predict system evolution, thus enabling risk assessment and response planning. No single researcher or research group will be able to achieve this ambitious vision alone. As a starting point, we recommend that the nascent ACM-L community agree on a common core model that supports all aspects—static and dynamic—needed for active conceptual modeling in support of learning from surprises. A common core will more likely gain the traction needed to sustain the extended ACM-L research effort that will yield the advertised benefits of learning from surprises.

  13. Three-dimensional conceptual model for the Hanford Site unconfined aquifer system: FY 1994 status report

    SciTech Connect

    Thorne, P.D.; Chamness, M.A.; Vermeul, V.R.; Macdonald, Q.C.; Schubert, S.E.

    1994-11-01

    This report documents work conducted during the fiscal year 1994 to development an improved three-dimensional conceptual model of ground-water flow in the unconfined aquifer system across the Hanford Site Ground-Water Surveillance Project, which is managed by Pacific Northwest Laboratory. The main objective of the ongoing effort to develop an improved conceptual model of ground-water flow is to provide the basis for improved numerical report models that will be capable of accurately predicting the movement of radioactive and chemical contaminant plumes in the aquifer beneath Hanford. More accurate ground-water flow models will also be useful in assessing the impacts of changes in facilities and operations. For example, decreasing volumes of operational waste-water discharge are resulting in a declining water table in parts of the unconfined aquifer. In addition to supporting numerical modeling, the conceptual model also provides a qualitative understanding of the movement of ground water and contaminants in the aquifer.

  14. Advanced turbine systems program--conceptual design and product development. Quarterly report, November 1994--January 1995

    SciTech Connect

    1995-02-01

    Research continued in the design and development of advanced gas turbine systems. This report presents progress towards turbine blade development, diffuser development, combustion noise investigations,catalytic combustion development, and diagnostic probe development.

  15. The Aggregate Exposure Pathway (AEP): A conceptual framework for advancing exposure science research and applications

    EPA Science Inventory

    Historically, risk assessment has relied upon toxicological data to obtain hazard-based reference levels, which are subsequently compared to exposure estimates to determine whether an unacceptable risk to public health may exist. Recent advances in analytical methods, biomarker ...

  16. Improvements in Thermal Protection Sizing Capabilities for TCAT: Conceptual Design for Advanced Space Transportation Systems

    NASA Technical Reports Server (NTRS)

    Olds, John R.; Izon, Stephen James

    2002-01-01

    The Thermal Calculation Analysis Tool (TCAT), originally developed for the Space Systems Design Lab at the Georgia Institute of Technology, is a conceptual design tool capable of integrating aeroheating analysis into conceptual reusable launch vehicle design. It provides Thermal Protection System (TPS) unit thicknesses and acreage percentages based on the geometry of the vehicle and a reference trajectory to be used in calculation of the total cost and weight of the vehicle design. TCAT has proven to be reasonably accurate at calculating the TPS unit weights for in-flight trajectories; however, it does not have the capability of sizing TPS materials above cryogenic fuel tanks for ground hold operations. During ground hold operations, the vehicle is held for a brief period (generally about two hours) during which heat transfer from the TPS materials to the cryogenic fuel occurs. If too much heat is extracted from the TPS material, the surface temperature may fall below the freezing point of water, thereby freezing any condensation that may be present at the surface of the TPS. Condensation or ice on the surface of the vehicle is potentially hazardous to the mission and can also damage the TPS. It is questionable whether or not the TPS thicknesses provided by the aeroheating analysis would be sufficiently thick to insulate the surface of the TPS from the heat transfer to the fuel. Therefore, a design tool has been developed that is capable of sizing TPS materials at these cryogenic fuel tank locations to augment TCAT's TPS sizing capabilities.

  17. Bayesian experimental design for identification of model propositions and conceptual model uncertainty reduction

    NASA Astrophysics Data System (ADS)

    Pham, Hai V.; Tsai, Frank T.-C.

    2015-09-01

    The lack of hydrogeological data and knowledge often results in different propositions (or alternatives) to represent uncertain model components and creates many candidate groundwater models using the same data. Uncertainty of groundwater head prediction may become unnecessarily high. This study introduces an experimental design to identify propositions in each uncertain model component and decrease the prediction uncertainty by reducing conceptual model uncertainty. A discrimination criterion is developed based on posterior model probability that directly uses data to evaluate model importance. Bayesian model averaging (BMA) is used to predict future observation data. The experimental design aims to find the optimal number and location of future observations and the number of sampling rounds such that the desired discrimination criterion is met. Hierarchical Bayesian model averaging (HBMA) is adopted to assess if highly probable propositions can be identified and the conceptual model uncertainty can be reduced by the experimental design. The experimental design is implemented to a groundwater study in the Baton Rouge area, Louisiana. We design a new groundwater head observation network based on existing USGS observation wells. The sources of uncertainty that create multiple groundwater models are geological architecture, boundary condition, and fault permeability architecture. All possible design solutions are enumerated using a multi-core supercomputer. Several design solutions are found to achieve an 80%-identifiable groundwater model in 5 years by using six or more existing USGS wells. The HBMA result shows that each highly probable proposition can be identified for each uncertain model component once the discrimination criterion is achieved. The variances of groundwater head predictions are significantly decreased by reducing posterior model probabilities of unimportant propositions.

  18. Development of a system model for advanced small modular reactors.

    SciTech Connect

    Lewis, Tom Goslee,; Holschuh, Thomas Vernon,

    2014-01-01

    This report describes a system model that can be used to analyze three advance small modular reactor (SMR) designs through their lifetime. Neutronics of these reactor designs were evaluated using Monte Carlo N-Particle eXtended (MCNPX/6). The system models were developed in Matlab and Simulink. A major thrust of this research was the initial scoping analysis of Sandias concept of a long-life fast reactor (LLFR). The inherent characteristic of this conceptual design is to minimize the change in reactivity over the lifetime of the reactor. This allows the reactor to operate substantially longer at full power than traditional light water reactors (LWRs) or other SMR designs (e.g. high temperature gas reactor (HTGR)). The system model has subroutines for lifetime reactor feedback and operation calculations, thermal hydraulic effects, load demand changes and a simplified SCO2 Brayton cycle for power conversion.

  19. A conceptual model to empower software requirements conflict detection and resolution with rule-based reasoning

    NASA Astrophysics Data System (ADS)

    Ahmad, Sabrina; Jalil, Intan Ermahani A.; Ahmad, Sharifah Sakinah Syed

    2016-08-01

    It is seldom technical issues which impede the process of eliciting software requirements. The involvement of multiple stakeholders usually leads to conflicts and therefore the need of conflict detection and resolution effort is crucial. This paper presents a conceptual model to further improve current efforts. Hence, this paper forwards an improved conceptual model to assist the conflict detection and resolution effort which extends the model ability and improves overall performance. The significant of the new model is to empower the automation of conflicts detection and its severity level with rule-based reasoning.

  20. A beginner's guide to writing the nursing conceptual model-based theoretical rationale.

    PubMed

    Gigliotti, Eileen; Manister, Nancy N

    2012-10-01

    Writing the theoretical rationale for a study can be a daunting prospect for novice researchers. Nursing's conceptual models provide excellent frameworks for placement of study variables, but moving from the very abstract concepts of the nursing model to the less abstract concepts of the study variables is difficult. Similar to the five-paragraph essay used by writing teachers to assist beginning writers to construct a logical thesis, the authors of this column present guidelines that beginners can follow to construct their theoretical rationale. This guide can be used with any nursing conceptual model but Neuman's model was chosen here as the exemplar.

  1. Moving from Victim to Survivor of Cultural Violence: A Conceptual Model

    ERIC Educational Resources Information Center

    Salazar, Carmen F.; Casto, Challon

    2008-01-01

    The authors propose the Moving From Victim to Survivor of Cultural Violence model, using the stages of D. W. Sue and D. Sue's (1999) Racial/Cultural Identity Development model. This conceptual model describes the process of first overcoming internalized sexism, domestic abuse, sexual harassment, rape, and other forms of oppression and then healing…

  2. A Conceptual View of the Officer Procurement Model (TOPOPS). Technical Report No. 73-73.

    ERIC Educational Resources Information Center

    Akman, Allan; Nordhauser, Fred

    This report presents the conceptual design of a computer-based linear programing model of the Air Force officer procurement system called TOPOPS. The TOPOPS model is an aggregate model which simulates officer accession and training and is directed at optimizing officer procurement in terms of either minimizing cost or maximizing accession quality…

  3. Applying Model Analysis to a Resource-Based Analysis of the Force and Motion Conceptual Evaluation

    ERIC Educational Resources Information Center

    Smith, Trevor I.; Wittmann, Michael C.; Carter, Tom

    2014-01-01

    Previously, we analyzed the Force and Motion Conceptual Evaluation in terms of a resources-based model that allows for clustering of questions so as to provide useful information on how students correctly or incorrectly reason about physics. In this paper, we apply model analysis to show that the associated model plots provide more information…

  4. A conceptual framework for organismal biology: linking theories, models, and data.

    PubMed

    Zamer, William E; Scheiner, Samuel M

    2014-11-01

    Implicit or subconscious theory is especially common in the biological sciences. Yet, theory plays a variety of roles in scientific inquiry. First and foremost, it determines what does and does not count as a valid or interesting question or line of inquiry. Second, theory determines the background assumptions within which inquiries are pursued. Third, theory provides linkages among disciplines. For these reasons, it is important and useful to develop explicit theories for biology. A general theory of organisms is developed, which includes 10 fundamental principles that apply to all organisms, and 6 that apply to multicellular organisms only. The value of a general theory comes from its utility to help guide the development of more specific theories and models. That process is demonstrated by examining two domains: ecoimmunology and development. For the former, a constitutive theory of ecoimmunology is presented, and used to develop a specific model that explains energetic trade-offs that may result from an immunological response of a host to a pathogen. For the latter, some of the issues involved in trying to devise a constitutive theory that covers all of development are explored, and a more narrow theory of phenotypic novelty is presented. By its very nature, little of a theory of organisms will be new. Rather, the theory presented here is a formal expression of nearly two centuries of conceptual advances and practice in research. Any theory is dynamic and subject to debate and change. Such debate will occur as part of the present, initial formulation, as the ideas presented here are refined. The very process of debating the form of the theory acts to clarify thinking. The overarching goal is to stimulate debate about the role of theory in the study of organisms, and thereby advance our understanding of them.

  5. Waste Receiving and Processing Facility Module 2A: Advanced Conceptual Design Report. Volume 1

    SciTech Connect

    Not Available

    1994-03-01

    This ACDR was performed following completed of the Conceptual Design Report in July 1992; the work encompassed August 1992 to January 1994. Mission of the WRAP Module 2A facility is to receive, process, package, certify, and ship for permanent burial at the Hanford site disposal facilities the Category 1 and 3 contact handled low-level radioactive mixed wastes that are currently in retrievable storage at Hanford and are forecast to be generated over the next 30 years by Hanford, and waste to be shipped to Hanford from about DOE sites. This volume provides an introduction to the ACDR process and the scope of the task along with a project summary of the facility, treatment technologies, cost, and schedule. Major areas of departure from the CDR are highlighted. Descriptions of the facility layout and operations are included.

  6. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    SciTech Connect

    Amann, J.; Bane, K.; /SLAC

    2009-10-30

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  7. Conceptual design of a self-deployable, high performance parabolic concentrator for advanced solar-dynamic power systems

    NASA Technical Reports Server (NTRS)

    Dehne, Hans J.

    1991-01-01

    NASA has initiated technology development programs to develop advanced solar dynamic power systems and components for space applications beyond 2000. Conceptual design work that was performed is described. The main efforts were the: (1) conceptual design of self-deploying, high-performance parabolic concentrator; and (2) materials selection for a lightweight, shape-stable concentrator. The deployment concept utilizes rigid gore-shaped reflective panels. The assembled concentrator takes an annular shape with a void in the center. This deployable concentrator concept is applicable to a range of solar dynamic power systems of 25 kW sub e to in excess of 75 kW sub e. The concept allows for a family of power system sizes all using the same packaging and deployment technique. The primary structural material selected for the concentrator is a polyethyl ethylketone/carbon fiber composite also referred to as APC-2 or Vitrex. This composite has a nearly neutral coefficient of thermal expansion which leads to shape stable characteristics under thermal gradient conditions. Substantial efforts were undertaken to produce a highly specular surface on the composite. The overall coefficient of thermal expansion of the composite laminate is near zero, but thermally induced stresses due to micro-movement of the fibers and matrix in relation to each other cause the surface to become nonspecular.

  8. Spacecraft Conceptual Design for the 8-Meter Advanced Technology Large Aperture Space Telescope (ATLAST)

    NASA Technical Reports Server (NTRS)

    Hopkins, Randall C.; Capizzo, Peter; Fincher, Sharon; Hornsby, Linda S.; Jones, David

    2010-01-01

    The Advanced Concepts Office at Marshall Space Flight Center completed a brief spacecraft design study for the 8-meter monolithic Advanced Technology Large Aperture Space Telescope (ATLAST-8m). This spacecraft concept provides all power, communication, telemetry, avionics, guidance and control, and thermal control for the observatory, and inserts the observatory into a halo orbit about the second Sun-Earth Lagrange point. The multidisciplinary design team created a simple spacecraft design that enables component and science instrument servicing, employs articulating solar panels for help with momentum management, and provides precise pointing control while at the same time fast slewing for the observatory.

  9. Conceptual model of sediment processes in the upper Yuba River watershed, Sierra Nevada, CA

    USGS Publications Warehouse

    Curtis, J.A.; Flint, L.E.; Alpers, C.N.; Yarnell, S.M.

    2005-01-01

    This study examines the development of a conceptual model of sediment processes in the upper Yuba River watershed; and we hypothesize how components of the conceptual model may be spatially distributed using a geographical information system (GIS). The conceptual model illustrates key processes controlling sediment dynamics in the upper Yuba River watershed and was tested and revised using field measurements, aerial photography, and low elevation videography. Field reconnaissance included mass wasting and channel storage inventories, assessment of annual channel change in upland tributaries, and evaluation of the relative importance of sediment sources and transport processes. Hillslope erosion rates throughout the study area are relatively low when compared to more rapidly eroding landscapes such as the Pacific Northwest and notable hillslope sediment sources include highly erodible andesitic mudflows, serpentinized ultramafics, and unvegetated hydraulic mine pits. Mass wasting dominates surface erosion on the hillslopes; however, erosion of stored channel sediment is the primary contributor to annual sediment yield. We used GIS to spatially distribute the components of the conceptual model and created hillslope erosion potential and channel storage models. The GIS models exemplify the conceptual model in that landscapes with low potential evapotranspiration, sparse vegetation, steep slopes, erodible geology and soils, and high road densities display the greatest hillslope erosion potential and channel storage increases with increasing stream order. In-channel storage in upland tributaries impacted by hydraulic mining is an exception. Reworking of stored hydraulic mining sediment in low-order tributaries continues to elevate upper Yuba River sediment yields. Finally, we propose that spatially distributing the components of a conceptual model in a GIS framework provides a guide for developing more detailed sediment budgets or numerical models making it an

  10. Navigating Tensions Between Conceptual and Metaconceptual Goals in the Use of Models

    NASA Astrophysics Data System (ADS)

    Delgado, Cesar

    2015-04-01

    Science education involves learning about phenomena at three levels: concrete (facts and generalizations), conceptual (concepts and theories), and metaconceptual (epistemology) (Snir et al. in J Sci Educ Technol 2(2):373-388, 1993). Models are key components in science, can help build conceptual understanding, and may also build metaconceptual understanding. Technology can transform teaching and learning by turning models into interactive simulations that learners can investigate. This paper identifies four characteristics of models and simulations that support conceptual learning but misconstrue models and science at a metaconceptual level. Ahistorical models combine the characteristics of several historical models; they conveniently compile ideas but misrepresent the history of science (Gilbert in Int J Sci Math Educ 2(2):115-130, 2004). Teleological models explain behavior in terms of a final cause; they can lead to useful heuristics but imply purpose in processes driven by chance and probability (Talanquer in Int J Sci Educ 29(7):853-870, 2007). Epistemological overreach occurs when models or simulations imply greater certainty and knowledge about phenomena than warranted; conceptualizing nature as being well known (e.g., having a mathematical structure) poses the danger of conflating model and reality or data and theory. Finally, models are inevitably ontologically impoverished. Real-world deviations and many variables are left out of models, as models' role is to simplify. Models and simulations also lose much of the sensory data present in phenomena. Teachers, designers, and professional development designers and facilitators must thus navigate the tension between conceptual and metaconceptual learning when using models and simulations. For each characteristic, examples are provided, along with recommendations for instruction and design. Prompts for explicit reflective activities around models are provided for each characteristic

  11. Development of a Conceptual Chum Salmon Emergence Model for Ives Island

    SciTech Connect

    Murray, Christopher J.; Geist, David R.; Arntzen, Evan V.; Bott, Yi-Ju; Nabelek, Marc A.

    2011-02-09

    The objective of the study described herein was to develop a conceptual model of chum salmon emergence that was based on empirical water temperature of the riverbed and river in specific locations where chum salmon spawn in the Ives Island area. The conceptual model was developed using water temperature data that have been collected in the past and are currently being collected in the Ives Island area. The model will be useful to system operators who need to estimate the complete distribution of chum salmon emergence (first emergence through final emergence) in order to balance chum salmon redd protection and power system operation.

  12. Adaptive Modeling, Engineering Analysis and Design of Advanced Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Hsu, Su-Yuen; Mason, Brian H.; Hicks, Mike D.; Jones, William T.; Sleight, David W.; Chun, Julio; Spangler, Jan L.; Kamhawi, Hilmi; Dahl, Jorgen L.

    2006-01-01

    This paper describes initial progress towards the development and enhancement of a set of software tools for rapid adaptive modeling, and conceptual design of advanced aerospace vehicle concepts. With demanding structural and aerodynamic performance requirements, these high fidelity geometry based modeling tools are essential for rapid and accurate engineering analysis at the early concept development stage. This adaptive modeling tool was used for generating vehicle parametric geometry, outer mold line and detailed internal structural layout of wing, fuselage, skin, spars, ribs, control surfaces, frames, bulkheads, floors, etc., that facilitated rapid finite element analysis, sizing study and weight optimization. The high quality outer mold line enabled rapid aerodynamic analysis in order to provide reliable design data at critical flight conditions. Example application for structural design of a conventional aircraft and a high altitude long endurance vehicle configuration are presented. This work was performed under the Conceptual Design Shop sub-project within the Efficient Aerodynamic Shape and Integration project, under the former Vehicle Systems Program. The project objective was to design and assess unconventional atmospheric vehicle concepts efficiently and confidently. The implementation may also dramatically facilitate physics-based systems analysis for the NASA Fundamental Aeronautics Mission. In addition to providing technology for design and development of unconventional aircraft, the techniques for generation of accurate geometry and internal sub-structure and the automated interface with the high fidelity analysis codes could also be applied towards the design of vehicles for the NASA Exploration and Space Science Mission projects.

  13. Advanced conceptual design report for the Z-Beamlet laser backlighter

    SciTech Connect

    Caird, J

    1999-05-31

    The Z-accelerator facility at Sandia National Laboratories (SNL) in Albuquerque, New Mexico, performs critical experiments on the physics of matter at extremely high energy density as part of the Department of Energy's nuclear weapons Stockpile Stewardship Program. In order to augment and enhance the value of experiments performed at this facility, the construction of a new x-ray backlighting diagnostic system is required. New information would be obtained by recording images and/or spectra of x-ray radiation transmitted through target materials as they evolve during Z-accelerator-driven experiments (or ''shots''). In this application, we generally think of the diagnostic x-rays as illumination produced behind the target materials and detected after passing through the Z-target. Hence the x-ray source is commonly called a ''backlighter.'' The methodology is a specific implementation of the general science known as x-ray radiography and/or x-ray spectroscopy. X-ray backlighter experiments have been performed in inertial confinement fusion (ICF) facilities in many countries. On Nova, experience with backlighters has been obtained since about 1986. An intense source of x-rays is produced by focusing one of its beams on a backlighter target nearby, while the other beams are used to create the high-energy-density conditions to be studied in the experiment. This conceptual design report describes how a laser-backlighter similar to one beam of Nova could be constructed for use at Sandia's Z-accelerator facility. The development of such a facility at Sandia is timely for two major reasons. First, at LLNL the Beamlet laser was decommissioned in FY98, and the Nova laser will be decommissioned in FY99, in preparation for activation of the National Ignition Facility (NIF). This will provide several million dollars worth of subsystems and components from which to construct other lasers, such as the Z-backlighter. Second, the new diagnostic capability at Sandia will provide a

  14. Model-based advanced process control of coagulation.

    PubMed

    Baxter, C W; Shariff, R; Stanley, S J; Smith, D W; Zhang, Q; Saumer, E D

    2002-01-01

    The drinking water treatment industry has seen a recent increase in the use of artificial neural networks (ANNs) for process modelling and offline process control tools and applications. While conceptual frameworks for integrating the ANN technology into the real-time control of complex treatment processes have been proposed, actual working systems have yet to be developed. This paper presents development and application of an ANN model-based advanced process control system for the coagulation process at a pilot-scale water treatment facility in Edmonton, Alberta, Canada. The system was successfully used to maintain a user-defined set point for effluent quality, by automatically varying operating conditions in response to changes in influent water quality. This new technology has the potential to realize significant operational cost saving for utilities when applied in full-scale applications.

  15. Conceptual Model of Offshore Wind Environmental Risk Evaluation System

    SciTech Connect

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.; Unwin, Stephen D.; Hamilton, Erin L.

    2010-06-01

    In this report we describe the development of the Environmental Risk Evaluation System (ERES), a risk-informed analytical process for estimating the environmental risks associated with the construction and operation of offshore wind energy generation projects. The development of ERES for offshore wind is closely allied to a concurrent process undertaken to examine environmental effects of marine and hydrokinetic (MHK) energy generation, although specific risk-relevant attributes will differ between the MHK and offshore wind domains. During FY10, a conceptual design of ERES for offshore wind will be developed. The offshore wind ERES mockup described in this report will provide a preview of the functionality of a fully developed risk evaluation system that will use risk assessment techniques to determine priority stressors on aquatic organisms and environments from specific technology aspects, identify key uncertainties underlying high-risk issues, compile a wide-range of data types in an innovative and flexible data organizing scheme, and inform planning and decision processes with a transparent and technically robust decision-support tool. A fully functional version of ERES for offshore wind will be developed in a subsequent phase of the project.

  16. Chemical Kinetic Modeling of Advanced Transportation Fuels

    SciTech Connect

    PItz, W J; Westbrook, C K; Herbinet, O

    2009-01-20

    Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.

  17. Conceptual model for early health technology assessment of current and novel heart valve interventions

    PubMed Central

    Huygens, Simone A; Rutten-van Mölken, Maureen P M H; Bekkers, Jos A; Bogers, Ad J J C; Bouten, Carlijn V C; Chamuleau, Steven A J; de Jaegere, Peter P T; Kappetein, Arie Pieter; Kluin, Jolanda; van Mieghem, Nicolas M D A; Versteegh, Michel I M; Witsenburg, Maarten; Takkenberg, Johanna J M

    2016-01-01

    Objective The future promises many technological advances in the field of heart valve interventions, like tissue-engineered heart valves (TEHV). Prior to introduction in clinical practice, it is essential to perform early health technology assessment. We aim to develop a conceptual model (CM) that can be used to investigate the performance and costs requirements for TEHV to become cost-effective. Methods After scoping the decision problem, a workgroup developed the draft CM based on clinical guidelines. This model was compared with existing models for cost-effectiveness of heart valve interventions, identified by systematic literature search. Next, it was discussed with a Delphi panel of cardiothoracic surgeons, cardiologists and a biomedical scientist (n=10). Results The CM starts with the valve implantation. If patients survive the intervention, they can remain alive without complications, die from non-valve-related causes or experience a valve-related event. The events are separated in early and late events. After surviving an event, patients can experience another event or die due to non-valve-related causes. Predictors will include age, gender, NYHA class, left ventricular function and diabetes. Costs and quality adjusted life years are to be attached to health conditions to estimate long-term costs and health outcomes. Conclusions We developed a CM that will serve as foundation of a decision-analytic model that can estimate the potential cost-effectiveness of TEHV in early development stages. This supports developers in deciding about further development of TEHV and identifies promising interventions that may result in faster take-up in clinical practice by clinicians and reimbursement by payers. PMID:27843569

  18. Advanced turbine systems phase II - conceptual design and product development. Final report, August 1993--July 1996

    SciTech Connect

    1996-10-01

    The National Energy Strategy (NES) calls for a balanced program of greater energy efficiency, use of alternative fuels, and the environmentally responsible development of all U.S. energy resources. Consistent with the NES, a Department of Energy (DOE) program has been created to develop Advanced Turbine Systems (ATS). The technical ATS requirements are based upon two workshops held in Greenville, SC that were sponsored by DOE and hosted by Clemson University. The objective of this 8-year program, managed jointly by DOE`s Office of Fossil Energy, and, Office of Conservation and Renewable Energy, is to develop natural-gas-fired base load power plants that will have cycle efficiencies greater than 60%, lower heating value (LHV), be environmentally superior to current technology, and also be cost competitive. The program will include work to transfer advanced technology to the coal- and biomass-fueled systems being developed in other DOE programs.

  19. Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site

    SciTech Connect

    Truex, Michael J.; Lee, Brady D.; Johnson, Christian D.; Qafoku, Nikolla P.; Last, George V.; Lee, Michelle H.; Kaplan, Daniel I.

    2015-09-01

    The fate and transport of 129I in the environment and potential remediation technologies are currently being studied as part of environmental remediation activities at the Hanford Site. A conceptual model describing the nature and extent of subsurface contamination, factors that control plume behavior, and factors relevant to potential remediation processes is needed to support environmental remedy decisions. Because 129I is an uncommon contaminant, relevant remediation experience and scientific literature are limited. Thus, the conceptual model also needs to both describe known contaminant and biogeochemical process information and to identify aspects about which additional information needed to effectively support remedy decisions. this document summarizes the conceptual model of iodine behavior relevant to iodine in the subsurface environment at the Hanford site.

  20. Conceptual design of an integrated technology model for carbon policy assessment.

    SciTech Connect

    Backus, George A.; Dimotakes, Paul E.

    2011-01-01

    This report describes the conceptual design of a technology choice model for understanding strategies to reduce carbon intensity in the electricity sector. The report considers the major modeling issues affecting technology policy assessment and defines an implementable model construct. Further, the report delineates the basis causal structure of such a model and attempts to establish the technical/algorithmic viability of pursuing model development along with the associated analyses.

  1. LIGHT SOURCE: Conceptual design of Hefei Advanced Light Source (HALS) injection system

    NASA Astrophysics Data System (ADS)

    Zhang, Shan-Cai; Wang, Lin; Feng, Guang-Yao; Wu, Cong-Feng; Li, Wei-Min; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.

  2. Advanced turbine systems program -- Conceptual design and product development. Final report

    SciTech Connect

    1996-07-26

    This Final Technical Report presents the accomplishments on Phase 2 of the Advanced Turbine Systems (ATS). The ATS is an advanced, natural gas fired gas turbine system that will represent a major advance on currently available industrial gas turbines in the size range of 1--20 MW. This report covers a market-driven development. The Market Survey reported in Section 5 identified the customer`s performance needs. This market survey used analyses performed by Solar turbine Incorporated backed up by the analyses done by two consultants, Research Decision Consultants (RDC) and Onsite Energy Corporation (Onsite). This back-up was important because it is the belief of all parties that growth of the ATS will depend both on continued participation in Solar`s traditional oil and gas market but to a major extent on a new market. This new market is distributed electrical power generation. Difficult decisions have had to be made to meet the different demands of the two markets. Available resources, reasonable development schedules, avoidance of schedule or technology failures, probable acceptance by the marketplace, plus product cost, performance and environmental friendliness are a few of the complex factors influencing the selection of the Gas Fired Advanced Turbine System described in Section 3. Section 4 entitled ``Conversion to Coal`` was a task which addresses the possibility of a future interruption to an economic supply of natural gas. System definition and analysis is covered in Section 6. Two major objectives were met by this work. The first was identification of those critical technologies that can support overall attainment of the program goals. Separate technology or component programs were begun to identify and parameterize these technologies and are described in Section 7. The second objective was to prepare parametric analyses to assess performance sensitivity to operating variables and to select design approaches to meet the overall program goals.

  3. 7-GeV Advanced Photon Source Instrumentation Initiative conceptual design report

    SciTech Connect

    Not Available

    1992-12-01

    In this APS Instrumentation Initiative, 2.5-m-long and 5-m-long insertion-device x-ray sources will be built on 9 straight sections of the APS storage ring, and an additional 9 bending-magnet sources will also be put in use. The front ends for these 18 x-ray sources will be built to contain and safeguard access to these bright x-ray beams. In addition, funds will be provided to build state-of-the-art insertion-device beamlines to meet scientific and technological research demands well into the next century. This new initiative will also include four user laboratory modules and a special laboratory designed to meet the x-ray imaging research needs of the users. The Conceptual Design Report (CDR) for the APS Instrumentation Initiative describes the scope of all the above technical and conventional construction and provides a detailed cost and schedule for these activities. According to these plans, this new initiative begins in FY 1994 and ends in FY 1998. The document also describes the preconstruction R D plans for the Instrumentation Initiative activities and provides the cost estimates for the required R D.

  4. 7-GeV Advanced Photon Source Instrumentation Initiative conceptual design report

    SciTech Connect

    Not Available

    1992-12-01

    In this APS Instrumentation Initiative, 2.5-m-long and 5-m-long insertion-device x-ray sources will be built on 9 straight sections of the APS storage ring, and an additional 9 bending-magnet sources will also be put in use. The front ends for these 18 x-ray sources will be built to contain and safeguard access to these bright x-ray beams. In addition, funds will be provided to build state-of-the-art insertion-device beamlines to meet scientific and technological research demands well into the next century. This new initiative will also include four user laboratory modules and a special laboratory designed to meet the x-ray imaging research needs of the users. The Conceptual Design Report (CDR) for the APS Instrumentation Initiative describes the scope of all the above technical and conventional construction and provides a detailed cost and schedule for these activities. According to these plans, this new initiative begins in FY 1994 and ends in FY 1998. The document also describes the preconstruction R&D plans for the Instrumentation Initiative activities and provides the cost estimates for the required R&D.

  5. Understanding Co-Development of Conceptual and Epistemic Understanding through Modeling Practices with Mobile Internet

    ERIC Educational Resources Information Center

    Ryu, Suna; Han, Yuhwha; Paik, Seoung-Hey

    2015-01-01

    The present study explores how engaging in modeling practice, along with argumentation, leverages students' epistemic and conceptual understanding in an afterschool science/math class of 16 tenth graders. The study also explores how students used mobile Internet phones (smart phones) productively to support modeling practices. As the modeling…

  6. Developing and Validating a Conceptual Model of Recurring Problems in Teaching Clinic

    ERIC Educational Resources Information Center

    Smith, C. Scott; Morris, Magdalena; Hill, William; Francovich, Chris; Christiano, Jennifer

    2006-01-01

    Recurrent problems in medical teaching clinic are common and difficult to address because of complex interpersonal dynamics. To minimize this difficulty, we developed a conceptual model that simplifies problems and identifies the root cause of tension between groups in clinic. We used recursive analysis and modeling of the data from a larger…

  7. Construction of a conceptual model of transport system for a coal mining region

    NASA Astrophysics Data System (ADS)

    Pristupa, Yu D.; Fryanov, V. N.; Pavlova, L. D.

    2016-10-01

    The methodological approaches to creation of a conceptual model of complex transport system for coal-mining region are substantiated. In the structure of the system base model the ensemble of local interconnected subsystems is distinguished. The local structure of the traffic management system of cargo transportation company is developed, the factors and indicators affecting the efficiency of cargo management are highlighted.

  8. Learning Goal Orientation, Formal Mentoring, and Leadership Competence in HRD: A Conceptual Model

    ERIC Educational Resources Information Center

    Kim, Sooyoung

    2007-01-01

    Purpose: The purpose of this paper is to suggest a conceptual model of formal mentoring as a leadership development initiative including "learning goal orientation", "mentoring functions", and "leadership competencies" as key constructs of the model. Design/methodology/approach: Some empirical studies, though there are not many, will provide…

  9. A Conceptual Model of Intrapreneurship in the Iranian Agricultural Extension Organization: Implications for HRD

    ERIC Educational Resources Information Center

    Karimi, Asef; Malekmohamadi, Iraj; Daryani, Mahmoud Ahmadpour; Rezvanfar, Ahmad

    2011-01-01

    Purpose: This study seeks to build a conceptual model of agricultural extension intrapreneurship that discusses the concept and phenomenon of intrapreneurship as well as its prerequisites and outcomes. The proposed model is intended to depict the main factors that affect the phenomena of intrapreneurship within the agricultural extension…

  10. A Model of Conceptual Learning and Development: Empirical Validation of the Concept Attainment Levels.

    ERIC Educational Resources Information Center

    Ingison, Linda J.

    Four hundred students, ranging from 5 to 15 years of age, were administered a series of tests of concept learning and development as a test of the Conceptual Learning and Development (CLD) model. Various levels of attainment of the concept of "equilateral triangle" were measured. The CLD model predicts that a decreasing number of students at a…

  11. A Dyadic Approach: Applying a Developmental-Conceptual Model to Couples Coping with Chronic Illness

    ERIC Educational Resources Information Center

    Checton, Maria G.; Magsamen-Conrad, Kate; Venetis, Maria K.; Greene, Kathryn

    2015-01-01

    The purpose of the present study was to apply Berg and Upchurch's developmental-conceptual model toward a better understanding of how couples cope with chronic illness. Specifically, a model was hypothesized in which proximal factors (relational quality), dyadic appraisal (illness interference), and dyadic coping (partner support) influence…

  12. Conceptualization of an R&D Based Learning-to-Innovate Model for Science Education

    ERIC Educational Resources Information Center

    Lai, Oiki Sylvia

    2013-01-01

    The purpose of this research was to conceptualize an R & D based learning-to-innovate (LTI) model. The problem to be addressed was the lack of a theoretical L TI model, which would inform science pedagogy. The absorptive capacity (ACAP) lens was adopted to untangle the R & D LTI phenomenon into four learning processes: problem-solving via…

  13. Conceptual Incoherence as a Result of the Use of Multiple Historical Models in School Textbooks

    ERIC Educational Resources Information Center

    Gericke, Niklas M.; Hagberg, Mariana

    2010-01-01

    This paper explores the occurrence of conceptual incoherence in upper secondary school textbooks resulting from the use of multiple historical models. Swedish biology and chemistry textbooks, as well as a selection of books from English speaking countries, were examined. The purpose of the study was to identify which models are used to represent…

  14. Introductory Biology Students' Conceptual Models and Explanations of the Origin of Variation

    ERIC Educational Resources Information Center

    Bray Speth, Elena; Shaw, Neil; Momsen, Jennifer; Reinagel, Adam; Le, Paul; Taqieddin, Ranya; Long, Tammy

    2014-01-01

    Mutation is the key molecular mechanism generating phenotypic variation, which is the basis for evolution. In an introductory biology course, we used a model-based pedagogy that enabled students to integrate their understanding of genetics and evolution within multiple case studies. We used student-generated conceptual models to assess…

  15. A Conceptual Model of Medical Student Well-Being: Promoting Resilience and Preventing Burnout

    ERIC Educational Resources Information Center

    Dunn, Laura B.; Iglewicz, Alana; Moutier, Christine

    2008-01-01

    Objective: This article proposes and illustrates a conceptual model of medical student well-being. Method: The authors reviewed the literature on medical student stress, coping, and well-being and developed a model of medical student coping termed the "coping reservoir." Results: The reservoir can be replenished or drained by various aspects of…

  16. The Relation of Story Structure to a Model of Conceptual Change in Science Learning

    ERIC Educational Resources Information Center

    Klassen, Stephen

    2010-01-01

    Although various reasons have been proposed to explain the potential effectiveness of science stories to promote learning, no explicit relationship of stories to learning theory in science has been propounded. In this paper, two structurally analogous models are developed and compared: a structural model of stories and a temporal conceptual change…

  17. Using Analogy and Model to Enhance Conceptual Change in Thai Middle School Students

    ERIC Educational Resources Information Center

    Wichaidit, Sittichai; Wongyounoi, Somson; Dechsri, Precharn; Chaivisuthangkura, Parin

    2011-01-01

    This study examined conceptual change of Thai middle school students after learning photosynthesis with analogy and model. The analogy mapped key features from the analog (cooking food) to the target concept (photosynthesis). Modeling photosynthesis activity provided the opportunity for students to understand how plants use sugar to synthesize…

  18. A Conceptual Operational Model for Command and Control of International Missions in the Canadian Forces

    DTIC Science & Technology

    2002-09-01

    Description Capture Method Larry Cochran and Kendall Wheaton 4 IDEF3 is an appropriate method for use in the COP21 operational model because it captures the...with each element (Arrow entities and Box activities) is information that describes the entity or activity. The Modeling Process The COP21 Conceptual

  19. Geographers in the Post-Industrial Age: A Conceptual Curriculum Model for Geography.

    ERIC Educational Resources Information Center

    Verduin-Muller, Henriette

    The document describes a conceptual curriculum model for designing original geographical curriculum materials. The model emanated from a series of research projects at the Geographical Institute's Department of Geography for Education at the Rijksuniversiteit of Utrecht, the Netherlands. The objective of the research was to gain insight into the…

  20. A Conceptual Model of Management Learning in Micro Businesses: Implications for Research and Policy

    ERIC Educational Resources Information Center

    Devins, David; Gold, Jeff; Johnson, Steve; Holden, Rick

    2005-01-01

    Purpose: This article proposes the development of a conceptual model to help understand the nature of management learning in the micro business context and to inform research and policy discourse. Design/Methodology/Approach: The model is developed on the basis of a literature search and review of academic and grey literature. Findings: The…

  1. The Role of Model Building in Problem Solving and Conceptual Change

    ERIC Educational Resources Information Center

    Lee, Chwee Beng; Jonassen, David; Teo, Timothy

    2011-01-01

    This study examines the effects of the activity of building systems models for school-based problems on problem solving and on conceptual change in elementary science classes. During a unit on the water cycle in an Asian elementary school, students constructed systems models of the water cycle. We found that representing ill-structured problems as…

  2. Computer-based creativity enhanced conceptual design model for non-routine design of mechanical systems

    NASA Astrophysics Data System (ADS)

    Li, Yutong; Wang, Yuxin; Duffy, Alex H. B.

    2014-11-01

    Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure(FBS) model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model(CECD) for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions(BOA), and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

  3. Multi-model groundwater-management optimization: reconciling disparate conceptual models

    NASA Astrophysics Data System (ADS)

    Timani, Bassel; Peralta, Richard

    2015-09-01

    Disagreement among policymakers often involves policy issues and differences between the decision makers' implicit utility functions. Significant disagreement can also exist concerning conceptual models of the physical system. Disagreement on the validity of a single simulation model delays discussion on policy issues and prevents the adoption of consensus management strategies. For such a contentious situation, the proposed multi-conceptual model optimization (MCMO) can help stakeholders reach a compromise strategy. MCMO computes mathematically optimal strategies that simultaneously satisfy analogous constraints and bounds in multiple numerical models that differ in boundary conditions, hydrogeologic stratigraphy, and discretization. Shadow prices and trade-offs guide the process of refining the first MCMO-developed `multi-model strategy into a realistic compromise management strategy. By employing automated cycling, MCMO is practical for linear and nonlinear aquifer systems. In this reconnaissance study, MCMO application to the multilayer Cache Valley (Utah and Idaho, USA) river-aquifer system employs two simulation models with analogous background conditions but different vertical discretization and boundary conditions. The objective is to maximize additional safe pumping (beyond current pumping), subject to constraints on groundwater head and seepage from the aquifer to surface waters. MCMO application reveals that in order to protect the local ecosystem, increased groundwater pumping can satisfy only 40 % of projected water demand increase. To explore the possibility of increasing that pumping while protecting the ecosystem, MCMO clearly identifies localities requiring additional field data. MCMO is applicable to other areas and optimization problems than used here. Steps to prepare comparable sub-models for MCMO use are area-dependent.

  4. GEOQUÌMICO : an interactive tool for comparing sorption conceptual models (surface complexation modeling verus K[D]).

    SciTech Connect

    Hammond, Glenn E.; Cygan, Randall Timothy

    2007-11-01

    Within reactive geochemical transport, several conceptual models exist for simulating sorption processes in the subsurface. Historically, the K{sub D} approach has been the method of choice due to ease of implementation within a reactive transport model and straightforward comparison with experimental data. However, for modeling complex sorption phenomenon (e.g. sorption of radionuclides onto mineral surfaces), this approach does not systematically account for variations in location, time, or chemical conditions, and more sophisticated methods such as a surface complexation model (SCM) must be utilized. It is critical to determine which conceptual model to use; that is, when the material variation becomes important to regulatory decisions. The geochemical transport tool GEOQUIMICO has been developed to assist in this decision-making process. GEOQUIMICO provides a user-friendly framework for comparing the accuracy and performance of sorption conceptual models. The model currently supports the K{sub D} and SCM conceptual models. The code is written in the object-oriented Java programming language to facilitate model development and improve code portability. The basic theory underlying geochemical transport and the sorption conceptual models noted above is presented in this report. Explanations are provided of how these physicochemical processes are instrumented in GEOQUIMICO and a brief verification study comparing GEOQUIMICO results to data found in the literature is given.

  5. Coastal Modeling System Advanced Topics

    DTIC Science & Technology

    2012-06-18

    is the CMS? Integrated wave, current, and morphology change model in the Surface-water Modeling System (SMS). Why CMS? Operational at 10...Coupled with spectral wave model (CMS-Wave)  Wave-current interactions  Inline sediment transport and morphology change  Non-equilibrium...Easy to setup  Telescoping grid: Efficient and flexible  Solver options  Implicit: Tidal flow, long-term morphology change. ~10 min

  6. Conceptual Models of Depression in Primary Care Patients: A Comparative Study

    PubMed Central

    Karasz, Alison; Garcia, Nerina; Ferri, Lucia

    2009-01-01

    Conventional psychiatric treatment models are based on a biopsychiatric model of depression. A plausible explanation for low rates of depression treatment utilization among ethnic minorities and the poor is that members of these communities do not share the cultural assumptions underlying the biopsychiatric model. The study examined conceptual models of depression among depressed patients from various ethnic groups, focusing on the degree to which patients’ conceptual models ‘matched’ a biopsychiatric model of depression. The sample included 74 primary care patients from three ethnic groups screening positive for depression. We administered qualitative interviews assessing patients’ conceptual representations of depression. The analysis proceeded in two phases. The first phase involved a strategy called ‘quantitizing’ the qualitative data. A rating scheme was developed and applied to the data by a rater blind to study hypotheses. The data was subjected to statistical analyses. The second phase of the analysis involved the analysis of thematic data using standard qualitative techniques. Study hypotheses were largely supported. The qualitative analysis provided a detailed picture of primary care patients’ conceptual models of depression and suggested interesting directions for future research. PMID:20182550

  7. Modeling of Spacecraft Advanced Chemical Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Benfield, Michael P. J.; Belcher, Jeremy A.

    2004-01-01

    This paper outlines the development of the Advanced Chemical Propulsion System (ACPS) model for Earth and Space Storable propellants. This model was developed by the System Technology Operation of SAIC-Huntsville for the NASA MSFC In-Space Propulsion Project Office. Each subsystem of the model is described. Selected model results will also be shown to demonstrate the model's ability to evaluate technology changes in chemical propulsion systems.

  8. Modeling Change Over Time: Conceptualization, Measurement, Analysis, and Interpretation

    DTIC Science & Technology

    2009-11-12

    models can be specified and tested using any of the widely available structural equation modeling programs such as AMOS (Arbuckle, 1999), EQS...because the programs were not specifically written for multilevel analyses. MPLUS (Muthen & Muthen, 2004) is a structural equation modeling program

  9. Conceptual design of a fast-ion D-alpha diagnostic on experimental advanced superconducting tokamak

    SciTech Connect

    Huang, J. Wan, B.; Hu, L.; Hu, C.; Heidbrink, W. W.; Zhu, Y.; Hellermann, M. G. von; Gao, W.; Wu, C.; Li, Y.; Fu, J.; Lyu, B.; Yu, Y.; Ye, M.; Shi, Y.

    2014-11-15

    To investigate the fast ion behavior, a fast ion D-alpha (FIDA) diagnostic system has been planned and is presently under development on Experimental Advanced Superconducting Tokamak. The greatest challenges for the design of a FIDA diagnostic are its extremely low intensity levels, which are usually significantly below the continuum radiation level and several orders of magnitude below the bulk-ion thermal charge-exchange feature. Moreover, an overlaying Motional Stark Effect (MSE) feature in exactly the same wavelength range can interfere. The simulation of spectra code is used here to guide the design and evaluate the diagnostic performance. The details for the parameters of design and hardware are presented.

  10. Efforts to improve patient safety in large, capitated medical groups: description and conceptual model.

    PubMed

    Miller, Robert H; Bovbjerg, Randall R

    2002-06-01

    Medical care should be safer. Inpatient problems and solutions have received the most attention; this outpatient qualitative case study addresses a gap in knowledge. We describe safety improvements among large physician groups, model the key influences on their behavior, and identify beneficial public and private policies. All groups were trying to reduce medical injury, which was part of the sample design. The most commonly targeted problems are those that are similar across groups: shortcomings in diagnosis, abnormal tests follow-up, scope of practice and referral patterns, and continuity of care. Medical group innovators vary greatly, however, in implementation of improvements, that is, in the extent to which they implement process changes that identify events/problems, analyze and track incidents, decide how to change clinical and administrative practices, and monitor impacts of the changes. Our conceptual model identifies key determinants: (1) demand for safety comes from external factors: legal, market, and professional; (2) organizational responses depend on internal factors: group size, scope, and integration; leadership and governance; professional culture; information-system assets; and financial and intellectual capital. Further, safety is an aspect of quality (the same tools, decision making, interventions, and monitoring apply), and safety management benefits from prior efficiency management (similar skills and culture of innovation). Observed variation in even simple safeguards shows that existing safety incentives are too weak. Our model suggests that the biggest improvement would come from boosting the demand for quality and safety from both private and public larger group purchasers. Current policy relies too much on litigation and discipline, which have sometimes helped, but not solved, problems because they are inefficient, tend to drive needed information underground, and complicate needed cultural change. Patients' safety demand is also weak

  11. On the Performance of Alternate Conceptual Ecohydrological Models for Streamflow Prediction

    NASA Astrophysics Data System (ADS)

    Naseem, Bushra; Ajami, Hoori; Cordery, Ian; Sharma, Ashish

    2016-04-01

    A merging of a lumped conceptual hydrological model with two conceptual dynamic vegetation models is presented to assess the performance of these models for simultaneous simulations of streamflow and leaf area index (LAI). Two conceptual dynamic vegetation models with differing representation of ecological processes are merged with a lumped conceptual hydrological model (HYMOD) to predict catchment scale streamflow and LAI. The merged RR-LAI-I model computes relative leaf biomass based on transpiration rates while the RR-LAI-II model computes above ground green and dead biomass based on net primary productivity and water use efficiency in response to soil moisture dynamics. To assess the performance of these models, daily discharge and 8-day MODIS LAI product for 27 catchments of 90 - 1600km2 in size located in the Murray - Darling Basin in Australia are used. Our results illustrate that when single-objective optimisation was focussed on maximizing the objective function for streamflow or LAI, the other un-calibrated predicted outcome (LAI if streamflow is the focus) was consistently compromised. Thus, single-objective optimization cannot take into account the essence of all processes in the conceptual ecohydrological models. However, multi-objective optimisation showed great strength for streamflow and LAI predictions. Both response outputs were better simulated by RR-LAI-II than RR-LAI-I due to better representation of physical processes such as net primary productivity (NPP) in RR-LAI-II. Our results highlight that simultaneous calibration of streamflow and LAI using a multi-objective algorithm proves to be an attractive tool for improved streamflow predictions.

  12. A conceptual data model and modelling language for fields and agents

    NASA Astrophysics Data System (ADS)

    de Bakker, Merijn; de Jong, Kor; Schmitz, Oliver; Karssenberg, Derek

    2016-04-01

    Modelling is essential in order to understand environmental systems. Environmental systems are heterogeneous because they consist of fields and agents. Fields have a value defined everywhere at all times, for example surface elevation and temperature. Agents are bounded in space and time and have a value only within their bounds, for example biomass of a tree crown or the speed of a car. Many phenomena have properties of both fields and agents. Although many systems contain both fields and agents and integration of these concepts would be required for modelling, existing modelling frameworks concentrate on either agent-based or field-based modelling and are often low-level programming frameworks. A concept is lacking that integrates fields and agents in a way that is easy to use for modelers who are not software engineers. To address this issue, we develop a conceptual data model that represents fields and agents uniformly. We then show how the data model can be used in a high-level modelling language. The data model represents fields and agents in space-time. Also relations and networks can be represented using the same concepts. Using the conceptual data model we can represent static and mobile agents that may have spatial and temporal variation within their extent. The concepts we use are phenomenon, property set, item, property, domain and value. The phenomenon is the thing that is modelled, which can be any real world thing, for example trees. A phenomenon usually consists of several items, e.g. single trees. The domain is the spatiotemporal location and/or extent for which the items in the phenomenon are defined. Multiple different domains can coexist for a given phenomenon. For example a domain describing the extent of the trees and a domain describing the stem locations. The same goes for the property, which is an attribute of the thing that is being modeled. A property has a value, which is possibly discretized, for example the biomass over the tree crown

  13. Conceptual ecosystem model of the Corpus Christi Bay National Estuary Program study area. Final report

    SciTech Connect

    Montagna, P.A.; Li, J.; Street, G.T.

    1996-01-01

    This report developed a conceptual ecosystem model, both pictorial and narrative, of the Corpus Christi Bay National Estuary Program (CCBNEP) study area. The model demonstrates ecosystem linkages at all trophic levels and substrate types, and provides a conceptual framework with which to assess ecological and environmental impacts (both episodic and cumulative) associated with external influences. The model is based on current scientific consensus regarding the modeling of estuarine ecosystem components, and data and information regarding these relationships within the study area. The model was developed to two levels of detail: (1) a detailed model suitable for the scientific and technical community; and, (2) a simple model suitable for use in CCBNEP public documents and management conference deliberations.

  14. Advanced turbine systems program: Conceptual design and product development. Topical report, November 1993

    SciTech Connect

    Wilken, L.S.

    1994-01-01

    This report has been prepared by Solar Turbines Incorporated (Solar) in accordance with Task 2 of the Advanced Turbine Systems (ATS) Contract. This report addresses only the work that will be performed under Task 8 (Design and Test of Critical Components) of the Contract. The discussion is divided into four general sections: Project Description; Potential Environmental Impacts; Required Permits and Licenses; and Environmental, Safety and Health (ES and H) Agency Contact Information. As described in further detail herein, the activities to occur during the project (i.e., Task 8) consists primarily of short duration testing of laboratory-scale components (or portions of components) for the ATS program. The testing involved will fall in the following general categories: recuperator, combustor, and blade/airfoil cooling. All activities contemplated will occur at existing facilities. Solar believes that the information in this report supports the conclusion that no significant environmental impacts will be associated with the project.

  15. A Conceptual Model for Engagement of the Online Learner

    ERIC Educational Resources Information Center

    Angelino, Lorraine M.; Natvig, Deborah

    2009-01-01

    Engagement of the online learner is one approach to reduce attrition rates. Attrition rates for classes taught through distance education are 10-20% higher than classes taught in a face-to-face setting. This paper introduces a Model for Engagement and provides strategies to engage the online learner. The Model depicts various opportunities where…

  16. Multicultural Issues in Organizational Consultation: A Conceptual Model for Intervention.

    ERIC Educational Resources Information Center

    Wright, Doris J.

    Despite ethical directives, most consultants do not understand fully how issues such as race, ethnicity, class, and gender impact organizational functioning. This paper presents a model of organizational culture that includes race and multicultural concerns. The cultural synergy model is based on the assumption that organizations have multiple…

  17. Conceptual Models To Study the Adaptation of the Oldest Old.

    ERIC Educational Resources Information Center

    Martin, Peter

    In recent years there has been an increased awareness about the growing number of the oldest old. A structural model for the study of the oldest old was introduced by Lehr (1987) and was built on experience with data from the Bonn Longitudinal Study of Aging. In the Lehr model, genetic, environmental, and ecological factors affect longevity…

  18. Characteristics and Conceptual Framework of the Easy-Play Model

    ERIC Educational Resources Information Center

    Lu, Chunlei; Steele, Kyle

    2014-01-01

    The Easy-Play Model offers a defined framework to organize games that promote an inclusive and enjoyable sport experience. The model can be implemented by participants playing sports in educational, recreational or social contexts with the goal of achieving an active lifestyle in an inclusive, cooperative and enjoyable environment. The Easy-Play…

  19. The Hourglass Approach: A Conceptual Model for Group Facilitators.

    ERIC Educational Resources Information Center

    Kriner, Lon S.; Goulet, Everett F.

    1983-01-01

    Presents a model to clarify the facilitator's role in working with groups. The Hourglass Approach model incorporates Carkhuff's empathetic levels of communication and Schultz's theory of personality. It is designed to be a systematic and comprehensive method usable with a variety of counseling approaches in all types of groups. (JAC)

  20. An independent verification and validation of the Future Theater Level Model conceptual model

    SciTech Connect

    Hartley, D.S. III; Kruse, K.L.; Martellaro, A.J.; Packard, S.L.; Thomas, B. Jr.; Turley, V.K.

    1994-08-01

    This report describes the methodology and results of independent verification and validation performed on a combat model in its design stage. The combat model is the Future Theater Level Model (FTLM), under development by The Joint Staff/J-8. J-8 has undertaken its development to provide an analysis tool that addresses the uncertainties of combat more directly than previous models and yields more rapid study results. The methodology adopted for this verification and validation consisted of document analyses. Included were detailed examination of the FTLM design documents (at all stages of development), the FTLM Mission Needs Statement, and selected documentation for other theater level combat models. These documents were compared to assess the FTLM as to its design stage, its purpose as an analytical combat model, and its capabilities as specified in the Mission Needs Statement. The conceptual design passed those tests. The recommendations included specific modifications as well as a recommendation for continued development. The methodology is significant because independent verification and validation have not been previously reported as being performed on a combat model in its design stage. The results are significant because The Joint Staff/J-8 will be using the recommendations from this study in determining whether to proceed with develop of the model.

  1. Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

    SciTech Connect

    Sobolik, S.R.; Ho, C.K.; Dunn, E.; Robey, T.H.; Cruz, W.T.

    1996-07-01

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document.

  2. A Conceptual Model of Childhood Adaptation to Type 1 Diabetes

    PubMed Central

    Whittemore, Robin; Jaser, Sarah; Guo, Jia; Grey, Margaret

    2010-01-01

    The Childhood Adaptation Model to Chronic Illness: Diabetes Mellitus was developed to identify factors that influence childhood adaptation to type 1 diabetes (T1D). Since this model was proposed, considerable research has been completed. The purpose of this paper is to update the model on childhood adaptation to T1D using research conducted since the original model was proposed. The framework suggests that individual and family characteristics, such as age, socioeconomic status, and in children with T1D, treatment modality (pump vs. injections), psychosocial responses (depressive symptoms and anxiety), and individual and family responses (self-management, coping, self-efficacy, family functioning, social competence) influence the level of adaptation. Adaptation has both physiologic (metabolic control) and psychosocial (QOL) components. This revised model provides greater specificity to the factors that influence adaptation to chronic illness in children. Research and clinical implications are discussed. PMID:20934079

  3. Model Standards Advance the Profession

    ERIC Educational Resources Information Center

    Journal of Staff Development, 2011

    2011-01-01

    Leadership by teachers is essential to serving the needs of students, schools, and the teaching profession. To that end, the Teacher Leadership Exploratory Consortium has developed Teacher Leader Model Standards to codify, promote, and support teacher leadership as a vehicle to transform schools for the needs of the 21st century. The Teacher…

  4. Integrating O/S models during conceptual design, part 2

    NASA Technical Reports Server (NTRS)

    Ebeling, Charles E.

    1994-01-01

    This report documents the procedures for utilizing and maintaining the Reliability & Maintainability Model (RAM) developed by the University of Dayton for the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) under NASA research grant NAG-1-1327. The purpose of the grant is to provide support to NASA in establishing operational and support parameters and costs of proposed space systems. As part of this research objective, the model described here was developed. Additional documentation concerning the development of this model may be found in Part 1 of this report. This is the 2nd part of a 3 part technical report.

  5. Empirical Validation of Conceptual Climate Models for the Mid-Pleistocene Transition

    NASA Astrophysics Data System (ADS)

    Gallatin, A.; Camp, C. D.

    2015-12-01

    Conceptual climate models are useful for testing hypotheses regarding the processes underlying observations; but they generally can only qualitatively match the empirical records. Models based on substantially different underlying physics can have comparable correlations with any given observation, thus robust model validation procedures are needed. The Mid-Pleistocene Transition (MPT) is an ideal test case for the development of such procedures because the character and cause of the transition from a dominant 41 kyr cycle in the early Pleistocene to a dominant 100 kyr cycle in the late Pleistocene is poorly understood. Using Ensemble Empirical Mode Decomposition, we analyze multiple conceptual models for the MPT which are based on differing physical hypotheses and show how modern time-series-analysis techniques can improve climate-model validation by extracting and comparing subtler features of both the observations and models.

  6. Review of the dWind Model Conceptual Results

    SciTech Connect

    Baring-Gould, Ian; Gleason, Michael; Preus, Robert; Sigrin, Ben

    2015-09-16

    This presentation provides an overview of the dWind model, including its purpose, background, and current status. Baring-Gould presented this material as part of the September 2015 WINDExchange webinar.

  7. Advanced Space Shuttle simulation model

    NASA Technical Reports Server (NTRS)

    Tatom, F. B.; Smith, S. R.

    1982-01-01

    A non-recursive model (based on von Karman spectra) for atmospheric turbulence along the flight path of the shuttle orbiter was developed. It provides for simulation of instantaneous vertical and horizontal gusts at the vehicle center-of-gravity, and also for simulation of instantaneous gusts gradients. Based on this model the time series for both gusts and gust gradients were generated and stored on a series of magnetic tapes, entitled Shuttle Simulation Turbulence Tapes (SSTT). The time series are designed to represent atmospheric turbulence from ground level to an altitude of 120,000 meters. A description of the turbulence generation procedure is provided. The results of validating the simulated turbulence are described. Conclusions and recommendations are presented. One-dimensional von Karman spectra are tabulated, while a discussion of the minimum frequency simulated is provided. The results of spectral and statistical analyses of the SSTT are presented.

  8. Modeling Advance Life Support Systems

    NASA Technical Reports Server (NTRS)

    Pitts, Marvin; Sager, John; Loader, Coleen; Drysdale, Alan

    1996-01-01

    Activities this summer consisted of two projects that involved computer simulation of bioregenerative life support systems for space habitats. Students in the Space Life Science Training Program (SLSTP) used the simulation, space station, to learn about relationships between humans, fish, plants, and microorganisms in a closed environment. One student complete a six week project to modify the simulation by converting the microbes from anaerobic to aerobic, and then balancing the simulation's life support system. A detailed computer simulation of a closed lunar station using bioregenerative life support was attempted, but there was not enough known about system restraints and constants in plant growth, bioreactor design for space habitats and food preparation to develop an integrated model with any confidence. Instead of a completed detailed model with broad assumptions concerning the unknown system parameters, a framework for an integrated model was outlined and work begun on plant and bioreactor simulations. The NASA sponsors and the summer Fell were satisfied with the progress made during the 10 weeks, and we have planned future cooperative work.

  9. Micromechanical modeling of advanced materials

    SciTech Connect

    Silling, S.A.; Taylor, P.A.; Wise, J.L.; Furnish, M.D.

    1994-04-01

    Funded as a laboratory-directed research and development (LDRD) project, the work reported here focuses on the development of a computational methodology to determine the dynamic response of heterogeneous solids on the basis of their composition and microstructural morphology. Using the solid dynamics wavecode CTH, material response is simulated on a scale sufficiently fine to explicitly represent the material`s microstructure. Conducting {open_quotes}numerical experiments{close_quotes} on this scale, the authors explore the influence that the microstructure exerts on the material`s overall response. These results are used in the development of constitutive models that take into account the effects of microstructure without explicit representation of its features. Applying this methodology to a glass-reinforced plastic (GRP) composite, the authors examined the influence of various aspects of the composite`s microstructure on its response in a loading regime typical of impact and penetration. As a prerequisite to the microscale modeling effort, they conducted extensive materials testing on the constituents, S-2 glass and epoxy resin (UF-3283), obtaining the first Hugoniot and spall data for these materials. The results of this work are used in the development of constitutive models for GRP materials in transient-dynamics computer wavecodes.

  10. Teaching Conceptual Model-Based Word Problem Story Grammar to Enhance Mathematics Problem Solving

    ERIC Educational Resources Information Center

    Xin, Yan Ping; Wiles, Ben; Lin, Yu-Ying

    2008-01-01

    Borrowing the concept of story grammar from reading comprehension literature, the purpose of this study was to examine the effect of teaching "word problem (WP) story grammar" on arithmetic WP solving that emphasizes the algebraic expression of mathematical relations in conceptual models. Participants were five students in Grades 4 and 5 with or…

  11. A Conceptual/Cross-cultural Model for Teaching Anthropology in the Elementary School.

    ERIC Educational Resources Information Center

    Dynneson, Thomas L.

    A conceptual/cross-cultural model, developed to help elementary teachers cope with the problems of initiating cultural, ethnic, or anthropology studies, is presented in five sections. (1) A brief description of the structure and methodology of anthropology defines in outline form the fields of cultural and social anthropology, physical…

  12. Testing Conceptual Frameworks of Nonexperimental Program Evaluation Designs Using Structural Equation Modeling

    ERIC Educational Resources Information Center

    Adedokun, Omolola A.; Childress, Amy L.; Burgess, Wilella D.

    2011-01-01

    A theory-driven approach to evaluation (TDE) emphasizes the development and empirical testing of conceptual models to understand the processes and mechanisms through which programs achieve their intended goals. However, most reported applications of TDE are limited to large-scale experimental/quasi-experimental program evaluation designs. Very few…

  13. Conceptual Design Model of Instructional Interfaces: Courseware for Inclusive Education System (IID4C) Distance Learning

    ERIC Educational Resources Information Center

    Tosho, Abdulrauf; Mutalib, Ariffin Abdul; Abdul-Salam, Sobihatun Nur

    2016-01-01

    This paper describes an ongoing study related to a conceptual design model, which is specific to instructional interface design to enhance courseware usage. It was found that most of the existing courseware applications focus on the needs of certain target with most of the courseware offer too little to inclusive learners. In addition, the use of…

  14. A New Conceptual Model for Principal Involvement and Professional Collaboration in Teacher Education

    ERIC Educational Resources Information Center

    Varrati, Anita M.; Lavine, Mary E.; Turner, Steven L.

    2009-01-01

    Background/Context: Beginning teachers often identify the school principal as a key figure for support and guidance. Few teacher education conceptual models exist that significantly integrate the building principal into the clinical experiences of teacher candidates. The rationale behind initiating discourse on principal involvement grows out of…

  15. Testing a Conceptual Model Related to Weight Perceptions, Physical Activity and Smoking in Adolescents

    ERIC Educational Resources Information Center

    Plotnikoff, Ronald C.; Bercovitz, Kim; Rhodes, Ryan E.; Loucaides, Constantinos A.; Karunamuni, Nandini

    2007-01-01

    The purpose of this study was to test a conceptual model based on theoretical and empirically supported relationships related to the influences of weight perceptions, weight concerns, desires to change weight, friends, age and location in relation to physical activity (PA) and smoking in adolescents. A total of 1242 males and 1446 females (mean…

  16. Exploring Conceptual Models for Community Engagement at Higher Education Institutions in South Africa

    ERIC Educational Resources Information Center

    Bender, Gerda

    2008-01-01

    A critical conceptual analysis of the South African Higher Education context reflects the lack of a structural and functional framework for the conceptualisation of community engagement (CE) in higher education. The purpose of this article is to explore a framework and model for the conceptualisation of CE for a better understanding of community…

  17. An Update on the Conceptual-Production Systems Model of Apraxia: Evidence from Stroke

    ERIC Educational Resources Information Center

    Stamenova, Vessela; Black, Sandra E.; Roy, Eric A.

    2012-01-01

    Limb apraxia is a neurological disorder characterized by an inability to pantomime and/or imitate gestures. It is more commonly observed after left hemisphere damage (LHD), but has also been reported after right hemisphere damage (RHD). The Conceptual-Production Systems model (Roy, 1996) suggests that three systems are involved in the control of…

  18. Designing Urban Intervention Programs: An Application of a Conceptual Model of Personality Development.

    ERIC Educational Resources Information Center

    Gooley, Ruby L.

    1995-01-01

    Describes the Chatham-Savannah Youth Futures Authority (YFA) program designed to help eliminate problems of urban youth, and analyzes the YFA with a focus on problems associated with female-headed, urban, black families. A summary of research is provided followed by a discussion of the conceptual model used as a basis for the program and an…

  19. A Conceptual Model for Teaching Critical Thinking in a Knowledge Economy

    ERIC Educational Resources Information Center

    Chadwick, Clifton

    2011-01-01

    Critical thinking, viewed as rational and analytic thinking, is crucial for participation in a knowledge economy and society. This article provides a brief presentation of the importance of teaching critical thinking in a knowledge economy; suggests a conceptual model for teaching thinking; examines research on the historical role of teachers in…

  20. The ISO Edi Conceptual Model Activity and Its Relationship to OSI.

    ERIC Educational Resources Information Center

    Fincher, Judith A.

    1990-01-01

    The edi conceptual model is being developed to define common structures, services, and processes that syntax-specific standards like X12 and EDIFACT could adopt. Open Systems Interconnection (OSI) is of interest to edi because of its potential to help enable global interoperability across Electronic Data Interchange (EDI) functional groups. A…

  1. Purpose and Pedagogy: A Conceptual Model for an ePortfolio

    ERIC Educational Resources Information Center

    Buyarski, Catherine A.; Aaron, Robert W.; Hansen, Michele J.; Hollingsworth, Cynthia D.; Johnson, Charles A.; Kahn, Susan; Landis, Cynthia M.; Pedersen, Joan S.; Powell, Amy A.

    2015-01-01

    This conceptual model emerged from the need to balance multiple purposes and perspectives associated with developing an ePortfolio designed to promote student development and success. A comprehensive review of literature from various disciplines, theoretical frameworks, and scholarship, including self-authorship, reflection, ePortfolio pedagogy,…

  2. A Study to Determine the Mental Models in Preschool Children's Conceptualization of a Desert Environment

    ERIC Educational Resources Information Center

    Ahi, Berat

    2016-01-01

    This study aimed to determine mental models and identify codes (schemes) used in conceptualizing a desert environment. The sample for this study consisted of 184--out of a total population of 3,630--children in preschool education in the central district of Kastamonu, Turkey. Within the scope of this study, the children were initially asked to…

  3. Dixie Valley Engineered Geothermal System Exploration Methodology Project, Baseline Conceptual Model Report

    DOE Data Explorer

    Joe Iovenitti

    2013-05-15

    The Engineered Geothermal System (EGS) Exploration Methodology Project is developing an exploration approach for EGS through the integration of geoscientific data. The Project chose the Dixie Valley Geothermal System in Nevada as a field laboratory site for methodlogy calibration purposes because, in the public domain, it is a highly characterized geothermal systems in the Basin and Range with a considerable amount of geoscience and most importantly, well data. This Baseline Conceptual Model report summarizes the results of the first three project tasks (1) collect and assess the existing public domain geoscience data, (2) design and populate a GIS database, and (3) develop a baseline (existing data) geothermal conceptual model, evaluate geostatistical relationships, and generate baseline, coupled EGS favorability/trust maps from +1km above sea level (asl) to -4km asl for the Calibration Area (Dixie Valley Geothermal Wellfield) to identify EGS drilling targets at a scale of 5km x 5km. It presents (1) an assessment of the readily available public domain data and some proprietary data provided by Terra-Gen Power, LLC, (2) a re-interpretation of these data as required, (3) an exploratory geostatistical data analysis, (4) the baseline geothermal conceptual model, and (5) the EGS favorability/trust mapping. The conceptual model presented applies to both the hydrothermal system and EGS in the Dixie Valley region.

  4. Conceptualizing Gifted Adolescent Girls Using the Bicultural Skills Model: Implications for School Counselors

    ERIC Educational Resources Information Center

    Pepperell, Jennifer L.; Rubel, Deborah J.; Maki, Laura A.

    2012-01-01

    In counseling research and practice gifted girls often lack identification as a cultural group with unique features. Yet, girls in this population have specific and distinct struggles, worldviews, and ways of navigating social and academic groups. The purpose of this conceptualization article is to apply the bicultural skills model to adolescent…

  5. Exploring the Postgraduate Research Climate and the Postgraduate Research Experience: A Conceptual Model

    ERIC Educational Resources Information Center

    Govender, K. K.

    2011-01-01

    The objective of this article is to develop a conceptual model aimed at improving the postgraduate research students' experience. Since postgraduate students "vote with their feet" an improved understanding of the postgraduate research service encounter may result in improving the quality of the encounter and so increasing throughput and…

  6. The Development of a Conceptual Model of Student Satisfaction with Their Experience in Higher Education

    ERIC Educational Resources Information Center

    Douglas, Jacqueline; McClelland, Robert; Davies, John

    2008-01-01

    Purpose: The purpose of this paper is to introduce a conceptual model of student satisfaction with their higher education (HE) experience, based on the identification of the variable determinants of student perceived quality and the impact of those variables on student satisfaction and/or dissatisfaction with the overall student experience. The…

  7. PIRPOSAL Model of Integrative STEM Education: Conceptual and Pedagogical Framework for Classroom Implementation

    ERIC Educational Resources Information Center

    Wells, John G.

    2016-01-01

    The PIRPOSAL model is both a conceptual and pedagogical framework intended for use as a pragmatic guide to classroom implementation of Integrative STEM Education. Designerly questioning prompted by a "need to know" serves as the basis for transitioning student designers within and among multiple phases while they progress toward an…

  8. College Men's Meanings of Masculinities and Contextual Influences: Toward a Conceptual Model

    ERIC Educational Resources Information Center

    Harris, Frank, III

    2010-01-01

    Based on a grounded theory study involving 68 male undergraduates, a conceptual model of the meanings college men ascribe to masculinities is proposed in this article. The participants equated masculinities with "being respected," "being confident and self-assured," "assuming responsibility," and "embodying physical prowess." Contextual factors…

  9. Knowledge Restructuring in Biology: Testing a Punctuated Model of Conceptual Change

    ERIC Educational Resources Information Center

    Mintzes, Joel; Quinn, Heather J.

    2007-01-01

    Emerging from a human constructivist view of learning and a punctuated model of conceptual change, these studies explored differences in the structural complexity and content validity of knowledge about prehistoric life depicted in concept maps by learners ranging in age from approximately 10 to 20 years. Study 1 (cross-age) explored the…

  10. What Research Administrators Need to Know about Researcher Development: Towards a New Conceptual Model

    ERIC Educational Resources Information Center

    Evans, Linda

    2011-01-01

    Located within the recently emerged field of researcher development, this article represents an attempt to make a key theoretical contribution to its knowledge base through a conceptual analysis. It presents as propositional knowledge an original theoretical model of the componential structure of researcher development, as interpreted and defined…

  11. Conceptual Resources for Constructing the Concepts of Electricity: The Role of Models, Analogies and Imagination

    ERIC Educational Resources Information Center

    Taber, Keith S.; de Trafford, Tom; Quail, Teresa

    2006-01-01

    The topic of electricity offers considerable challenge for the teacher hoping to provide students with an insight into scientific ways of thinking about circuits. The concepts used to make sense of electric circuits are abstract and students are expected to develop conceptual models of the relationship between non-observable qualities (current,…

  12. CONCEPTUAL BASIS FOR MULTI-ROUTE INTAKE DOSE MODELING USING AN ENERGY EXPENDITURE APPROACH

    EPA Science Inventory

    This paper provides the conceptual basis for a modeling logic that is currently being developed in the National Exposure Research Laboratory (NERL) of the U.S. Environmental Protection Agency ( EPA) for use in intake dose assessments involving substances that can enter the body...

  13. Pathways to Life Success: A Conceptual Model of Financial Well-Being for Young Adults

    ERIC Educational Resources Information Center

    Shim, Soyeon; Xiao, Jing J.; Barber, Bonnie L.; Lyons, Angela C.

    2009-01-01

    The purpose of this study is to describe and test a conceptual model of the potential antecedents and consequences of financial well-being in young adulthood. Data (N = 781) were collected via an online survey conducted at a large state university in the southwestern United States. Our results suggest that self-actualizing personal values,…

  14. Long-Term Conceptual Retrieval by College Biology Majors Following Model-Based Instruction

    ERIC Educational Resources Information Center

    Dauer, Joseph T.; Long, Tammy M.

    2015-01-01

    One of the goals of college-level introductory biology is to establish a foundation of knowledge and skills that can be built upon throughout a biology curriculum. In a reformed introductory biology course, we used iterative model construction as a pedagogical tool to promote students' understanding about conceptual connections, particularly those…

  15. Towards an Integrated Conceptual Model of International Student Adjustment and Adaptation

    ERIC Educational Resources Information Center

    Schartner, Alina; Young, Tony Johnstone

    2016-01-01

    Despite a burgeoning body of empirical research on "the international student experience", the area remains under-theorized. The literature to date lacks a guiding conceptual model that captures the adjustment and adaptation trajectories of this unique, growing, and important sojourner group. In this paper, we therefore put forward a…

  16. Conceptual Model for the Transport of Energetic Residues from Surface Soil to Groundwater by Range Activities

    DTIC Science & Technology

    2006-11-01

    ER D C/ CR R EL T R -0 6 - 1 8 Conceptual Model for the Transport of Energetic Residues from Surface Soil to Groundwater by Range...compounds potentially migrating to groundwater. The goals of the report are to 1 ) review and summarize previous work; 2) identify data gaps; 3) provide...Nomenclature.......................................................................................................................................viii 1

  17. Technology, Demographic Characteristics and E-Learning Acceptance: A Conceptual Model Based on Extended Technology Acceptance Model

    ERIC Educational Resources Information Center

    Tarhini, Ali; Elyas, Tariq; Akour, Mohammad Ali; Al-Salti, Zahran

    2016-01-01

    The main aim of this paper is to develop an amalgamated conceptual model of technology acceptance that explains how individual, social, cultural and organizational factors affect the students' acceptance and usage behaviour of the Web-based learning systems. More specifically, the proposed model extends the Technology Acceptance Model (TAM) to…

  18. A New Model to Facilitate Individualized Case Conceptualization and Treatment of Social Phobia: An Examination and Reaction to Moscovitch's Model

    ERIC Educational Resources Information Center

    Heimberg, Richard G.

    2009-01-01

    Moscovitch's (2009) model of social phobia is put forth as an integration and extension of previous cognitive-behavioral models. The author asserts that his approach overcomes a number of shortcomings of previous models and will serve to better guide case conceptualization, treatment planning, and intervention implementation for clients with…

  19. Nutrient supply and mercury dynamics in marine ecosystems: A conceptual model

    PubMed Central

    Chen, Celia Y.; Hammerschmidt, Chad R.; Mason, Robert P.; Gilmour, Cynthia C.; Sunderland, Elsie M.; Greenfield, Ben K.; Buckman, Kate L.; Lamborg, Carl H.

    2013-01-01

    There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine ecosystems. One of the challenges in assessing these effects is that the cycling and trophic transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change the transport, transformations and fate of Hg, including increases in fixation of organic carbon and deposition to sediments, decreases in the redox status of sediments and changes in fish habitat. In this paper we present a conceptual model which suggests that increases in loading of reactive N to marine ecosystems might alter Hg dynamics, decreasing bioavailabilty and trophic transfer. This conceptual model is most applicable to coastal waters, but may also be relevant to the pelagic ocean. We present information from case studies that both support and challenge this conceptual model, including marine observations across a nutrient gradient; results of a nutrient-trophic transfer Hg model for pelagic and coastal ecosystems; observations of Hg species, and nutrients from coastal sediments in the northeastern U.S.; and an analysis of fish Hg concentrations in estuaries under different nutrient loadings. These case studies suggest that changes in nutrient loading can impact Hg dynamics in coastal and open ocean ecosystems. Unfortunately none of the case studies is comprehensive; each only addresses a portion of the conceptual model and has limitations. Nevertheless, our conceptual model has important management implications. Many estuaries near developed areas are impaired due to elevated nutrient inputs. Widespread efforts are underway to control N loading and restore coastal ecosystem function. An unintended consequence of nutrient control measures could be to exacerbate problems associated with Hg

  20. Advanced Turbine Systems Program, Conceptual Design and Product Development. Task 6, System definition and analysis

    SciTech Connect

    1995-04-01

    The strategy of the ATS program is to develop a new baseline for industrial gas turbine systems for the 21st century, meeting the buying criteria of industrial gas turbine end users, and having growth potential. These criteria guided the Solar ATS Team in selecting the system definition described in this Topical Report. The key to selecting the ATS system definition was meeting or exceeding each technical goal without negatively impacting other commercial goals. Among the most crucial goals are the buying criteria of the industrial gas turbine market. Solar started by preliminarily considering several cycles with the potential to meet ATS program goals. These candidates were initially narrowed based on a qualitative assessment of several factors such as the potential for meeting program goals and for future growth; the probability of successful demonstration within the program`s schedule and expected level of funding; and the appropriateness of the cycle in light of end users` buying criteria. A first level Quality Function Deployment (QFD) analysis then translated customer needs into functional requirements, and ensured favorable interaction between concept features. Based on this analysis, Solar selected a recuperated cycle as the best approach to fulfilling both D.O.E. and Solar marketing goals. This report details the design and analysis of the selected engine concept, and explains how advanced features of system components achieve program goals. Estimates of cost, performance, emissions and RAMD (reliability, availability, maintainability, durability) are also documented in this report.

  1. Conceptual design of an advanced water/steam central solar receiver, volume 1

    NASA Astrophysics Data System (ADS)

    Matthews, F. T.; Payne, H. M.; Jones, B. O.; Snyder, T. K.; Davidson, M. J.

    1980-06-01

    A drum type boiler with forced circulation evaporator using rifled tubing can be designed for the high heat flux of a North field collector without the problems associated with departure of nuclear boiling. Existing boiler technology and materials can be used to design an advanced water/steam receiver. Rifled tubing was shown by test data to provide protection to evaporator panels at peak heat flux levels 30 percent greater than the design point of these receivers. Estimated budgetary type costs of these receivers vary from $10 per pound of steam for the large receiver to $13 per pound of steam for the smaller units. Fatigue life was conservatively calculated to be 30,000 full strain range cycles. This is adequate for the diurnal cycling, plus some cloud over a 30 year period. It is possible that the allowable creep fatigue cycles may be increased to 40,000 - 50,000 by an inelastic stress analysis. This analysis was recommended for future work and is required to resolve the cyclic lifetime of these receivers. Additional analysis is also needed to resolve receiver and plant control systems.

  2. Conceptual hierarchical modeling to describe wetland plant community organization

    USGS Publications Warehouse

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

  3. Hydrologic modelling for Lake Basaka: development and application of a conceptual water budget model.

    PubMed

    Dinka, Megersa O; Loiskandl, Willibald; Ndambuki, Julius M

    2014-09-01

    Quantification of fluxes of water into and out of terminal lakes like Basaka has fundamental challenges. This is due to the fact that accurate measurement and quantification of most of the parameters of a lake's hydrologic cycle are difficult. Furthermore, quantitative understanding of the hydrologic systems and hence, the data-intensive modelling is difficult in developing countries like Ethiopia due to limitation of sufficient recorded data. Therefore, formulation of a conceptual water balance model is extremely important as it presents a convenient analytical tool with simplified assumptions to simulate the magnitude of unknown fluxes. In the current study, a conceptual lake water balance model was systematically formulated, solved, calibrated, and validated successfully. Then, the surface water and groundwater interaction was quantified, and a mathematical relationship developed. The overall agreement between the observed and simulated lake stage at monthly time step was confirmed based on the standard performance parameters (R(2), MAE, RMSE, E(f)). The result showed that hydrological water balance of the lake is dominated by the groundwater (GW) component. The net GW flux in recent period (post-2000s) accounts about 56% of the total water inflow. Hence, GW plays a leading role in the hydrodynamics and existence of Lake Basaka and is mostly responsible for the expansion of the lake. Thus, identification of the potential sources/causes for the GW flux plays a leading role in order to limit the further expansion of the lake. Measurement of GW movement and exchange in the area is a high priority for future research.

  4. On the validity of first-order prediction limits for conceptual hydrologic models

    NASA Astrophysics Data System (ADS)

    Kuczera, George

    1988-11-01

    First-order analysis is a powerful method for evaluating the effect of parameter uncertainty propagating through a conceptual hydrologic model. However, its validity rests on the strong assumption that a first-order approximation is valid over the region of parameter space where there is significant parameter uncertainty. It is suggested that Beale's nonlinearity measure be used to check this assumption. This measure is based on the discrepancy between actual and linearized response for parameters randomly sampled from the surface of the 90% confidence ellipsoid. Examples involving two nonlinear conceptual models demonstrate that model nonlinearity is very much application-dependent, highlighting the need to compute Beale's nonlinearity measure in all model applications. Uncertainty in hydrologic response is induced not only by parameter uncertainty propagating through the model, but also by natural uncertainty arising from model and measurement error. Approximate prediction limits based on both parameter and natural uncertainty, are developed in a regression context, which employs an error model consistent with the residual characteristics found in conceptual hydrologic model applications. An example involving an eight-parameter streamflow yield model demonstrates dominance of natural over parameter uncertainty, emphasizing the need to include both forms of uncertainty when computing prediction limits.

  5. The Theoretical Foundation for Intercultural Business Communication: A Conceptual Model.

    ERIC Educational Resources Information Center

    Varner, Iris I.

    2000-01-01

    Develops a theoretical framework for intercultural business communication which sets it apart from intercultural communication and international business. Presents a model that discusses the intercultural, business, and communication strategies that are part of intercultural business communication. Examines how past articles in the field fit into…

  6. Fostering Radical Conceptual Change through Dual-Situated Learning Model

    ERIC Educational Resources Information Center

    She, Hsiao-Ching

    2004-01-01

    This article examines how the Dual-Situated Learning Model (DSLM) facilitates a radical change of concepts that involve the understanding of matter, process, and hierarchical attributes. The DSLM requires knowledge of students' prior beliefs of science concepts and the nature of these concepts. In addition, DSLM also serves two functions: it…

  7. Conceptual Models and Theory-Embedded Principles on Effective Schooling.

    ERIC Educational Resources Information Center

    Scheerens, Jaap

    1997-01-01

    Reviews models and theories on effective schooling. Discusses four rationality-based organization theories and a fifth perspective, chaos theory, as applied to organizational functioning. Discusses theory-embedded principles flowing from these theories: proactive structuring, fit, market mechanisms, cybernetics, and self-organization. The…

  8. Conceptual Processes for Linking Eutrophication and Network Models

    DTIC Science & Technology

    2006-08-01

    for improvements. Submerged Aquatic Vegetation (SAV). SAV biomass values from ICM (identified as SAV in Table 3) are two to three times lower...Dorothy H. Tillman, Dr. Carl F. Cerco, and Mr. Mark R. Noel of the Water Quality and Contaminant Modeling Branch, Enviromental Laboratory (EL

  9. The Historical Evolution of Theories and Conceptual Models for Nursing.

    ERIC Educational Resources Information Center

    Hawkins, Joellen W.

    The development of nursing models can be traced to the inception of nursing as a profession. Florence Nightingale laid the foundation for current nursing practice and differentiated nursing from medicine. The late 19th and early 20th centuries contributed a number of important nurse theorists, better known for other contributions to the neophyte…

  10. A Conceptual Model of Spirituality in Music Education

    ERIC Educational Resources Information Center

    van der Merwe, Liesl; Habron, John

    2015-01-01

    This article aims to describe the phenomenon of spirituality in music education by means of a model derived from the academic literature on the topic. Given the centrality of lived experience within this literature, we adopted a hermeneutic phenomenological theoretical framework to describe the phenomenon. The NCT (noticing, collecting, and…

  11. Clarifying the Conceptualization of Indicators within Different Models

    ERIC Educational Resources Information Center

    Wang, Jue; Engelhard, George, Jr.; Lu, Zhenqiu

    2014-01-01

    The authors of the focus article in this issue have emphasized the continuing confusion among some researchers regarding various indicators used in structural equation models (SEMs). Their major claim is that causal indicators are not inherently unstable, and even if they are unstable they are at least not more unstable than other types of…

  12. Iberian (South American) Model of Judicial Review: Toward Conceptual Framework

    ERIC Educational Resources Information Center

    Klishas, Andrey A.

    2016-01-01

    The paper explores Latin American countries legislation with the view to identify specific features of South American model of judicial review. The research methodology rests on comparative approach to analyzing national constitutions' provisions and experts' interpretations thereof. The constitutional provisions of Brazil, Peru, Mexico, and…

  13. Conceptual Complexity, Teaching Style and Models of Teaching.

    ERIC Educational Resources Information Center

    Joyce, Bruce; Weil, Marsha

    The focus of this paper is on the relative roles of personality and training in enabling teachers to carry out the kinds of complex learning models which are envisioned by curriculum reformers in the social sciences. The paper surveys some of the major research done in this area and concludes that: 1) Most teachers do not manifest the complex…

  14. Reliability and Maintainability Analysis: A Conceptual Design Model

    DTIC Science & Technology

    1972-03-01

    several contractors. Although this paper is ( ’ ,; written as if all design groi ;s were from the same contractor, the model developed does not depend...Figure 4.7. U% are not to think of the vertical axis as representing pleasure and pain . It simply represents the degree to which the individual is willing

  15. Animation Model to Conceptualize ATP Generation: A Mitochondrial Oxidative Phosphorylation

    ERIC Educational Resources Information Center

    Jena, Ananta Kumar

    2015-01-01

    Adenosine triphosphate (ATP) is the molecular unit of intracellular energy and it is the product of oxidative phosphorylation of cellular respiration uses in cellular processes. The study explores the growth of the misconception levels amongst the learners and evaluates the effectiveness of animation model over traditional methods. The data…

  16. A Conceptual Model for Extratropical Atmosphere-ocean Interaction

    NASA Astrophysics Data System (ADS)

    Zhao, B.; Reichler, T.

    2015-12-01

    Equipped with the current understanding for atmosphere-ocean interaction, we build a simple physically-based system of coupled equations to portray the relationships among major atmospheric and oceanic modes, including the NAO, AMO, AMOC, ENSO and stratospheric NAM. The simple model reproduces the strongly timescale-dependent character of the relationships, which changes in strength and direction on scales ranging from days to centuries. Another emphasis is placed on explicitly resolving the air-sea heat fluxes as a function of timescale to provide insight into the coupling between ocean and atmosphere. In constructing and testing the simple model we make use of a multi-millennium-long control integration with a fully coupled climate model. Cross-correlation, spectral analysis and inverse methods are employed to characterize important aspects of the interactions in the full and simple models. It is found that, a) Bjerknes' conjecture on ocean-atmosphere coupling, that is the atmosphere drives climate on high frequencies (days to months) while the ocean acts as the main source of climate variability on interannual and longer timescales, is confirmed; b) the AMOC can be readily understood as a harmonic oscillator driven by the NAO; c) the two-way interaction between NAO and AMO, and also the influence of ENSO on both NAO and AMO are essential for reproducing important correlation features; and d) the consideration of heat fluxes provides additional explanatory power to our model. Our approach not only helps to clarify our understanding for the nature of the atmosphere-ocean interaction problem but also raises new and intriguing questions for future research.

  17. Conceptual design of a high-intensity positron source for the Advanced Neutron Source

    SciTech Connect

    Hulett, L.D.; Eberle, C.C.

    1994-12-01

    The Advanced Neutron Source (ANS) is a planned new basic and applied research facility based on a powerful steady-state research reactor that provides neutrons for measurements and experiments in the fields of materials science and engineering, biology, chemistry, materials analysis, and nuclear science. The useful neutron flux will be at least five times more than is available in the world`s best existing reactor facility. Construction of the ANS provides a unique opportunity to build a positron spectroscopy facility (PSF) with very-high-intensity beams based on the radioactive decay of a positron-generating isotope. The estimated maximum beam current is 1000 to 5000 times higher than that available at the world`s best existing positron research facility. Such an improvement in beam capability, coupled with complementary detectors, will reduce experiment durations from months to less than one hour while simultaneously improving output resolution. This facility will remove the existing barriers to the routine use of positron-based analytical techniques and will be a giant step toward realization of the full potential of the application of positron spectroscopy to materials science. The ANS PSF is based on a batch cycle process using {sup 64}Cu isotope as the positron emitter and represents the status of the design at the end of last year. Recent work not included in this report, has led to a proposal for placing the laboratory space for the positron experiments outside the ANS containment; however, the design of the positron source is not changed by that relocation. Hydraulic and pneumatic flight tubes transport the source material between the reactor and the positron source where the beam is generated and conditioned. The beam is then transported through a beam pipe to one of several available detectors. The design presented here includes all systems necessary to support the positron source, but the beam pipe and detectors have not been addressed yet.

  18. Conceptual model of turbulent flameholding for scramjet combustors

    NASA Technical Reports Server (NTRS)

    Huber, P. W.

    1980-01-01

    New concepts and approaches to scramjet combustor design are presented. Blowoff was from failure of the recirculation-zone (RZ) flame to reach the dividing streamline (DS) at the rear stagnation zone. Increased turbulent exchange across the DS helped flameholding due to forward movement of the flame anchor point inside the RZ. Modeling of the blowoff phenomenon was based on a mass conservation concept involving the traverse of a flame element across the RZ and a flow element along the DS. The scale required to achieve flameholding, predicted by the model, showed a strong adverse effect of low pressure and low fuel equivalence ratio, moderate effect of flight Mach number, and little effect of temperature recovery factor. Possible effects of finite rate chemistry on flameholding and flamespreading in scramjets are discussed and recommendations for approaches to engine combustor design as well as for needed research to reduce uncertainties in the concepts are made.

  19. The Effects of Common Knowledge Construction Model Sequence of Lessons on Science Achievement and Relational Conceptual Change

    ERIC Educational Resources Information Center

    Ebenezer, Jazlin; Chacko, Sheela; Kaya, Osman Nafiz; Koya, Satya Kiran; Ebenezer, Devairakkam Luke

    2010-01-01

    The purpose of this study was to investigate the effects of the Common Knowledge Construction Model (CKCM) lesson sequence, an intervention based both in conceptual change theory and in Phenomenography, a subset of conceptual change theory. A mixed approach was used to investigate whether this model had a significant effect on 7th grade students'…

  20. Conceptual Model for Assessing Restoration of Puget Sound Nearshore Ecosystems

    DTIC Science & Technology

    2006-10-01

    29 A.18. Simulation: The final step is to view an animation that simulates these prescribed processes as they...Puget Sound nearShore PartnerShiP Technical Report 3 A.19. Expected events: As the model animation simulates the removal of the bulkhead forward in...among upland, sediments, and biology. (See Figure 12 for abbreviation defintions .) 16 Puget Sound nearShore PartnerShiP Technical Report 3 beach

  1. Advanced turbine systems program conceptual design and product development. Task 3 -- System selection; Topical report

    SciTech Connect

    White, D.J.

    1994-07-01

    Solar Turbines Incorporated has elected to pursue an intercooled and recuperated (ICR) gas turbine system to exceed the goals of the DOE Advanced Turbine Systems (ATS) program, which are to develop and commercialize an industrial gas turbine system that operates at thermal efficiencies at least 15% higher than 1991 products, and with emissions not exceeding eight ppmv NOx and 20 ppmv CO and UHC. Solar`s goal is to develop a commercially viable industrial system (3--20 MW) driven by a gas turbine engine with a thermal efficiency of 50% (ATS50), with the flexibility to meet the differing operational requirements of various markets. Dispersed power generation is currently considered to be the primary future target market for the ICR in the 5--15 MW size class. The ICR integrated system approach provides an ideal candidate for the assumed dispersed power market, with its small footprint, easy transportability, and environmental friendliness. In comparison with other systems that use water or toxic chemicals such as ammonia for NOx control, the ICR has no consumables other than fuel and air. The low pressure ratio of the gas turbine engine also is favorable in that less parasitic power is needed to pump the natural gas into the combustor than for simple-cycle machines. Solar has narrowed the ICR configuration to two basic approaches, a 1-spool, and a 2-spool version of the ATS50. The 1-spool engine will have a lower first-cost but lower part-power efficiencies. The 2-spool ATS may not only have better part-power efficiency, its efficiency will also be less sensitive to reduced turbine rotor inlet temperature levels. Thus hot-end parts life can be increased with only small sacrifices in efficiency. The flexibility of the 2-spool arrangement in meeting customer needs is its major advantage over the 1-spool. This Task 3 Topical Report is intended to present Solar`s preliminary system selection based upon the initial trade-off studies performed to date.

  2. Advancing a sociotechnical systems approach to workplace safety – developing the conceptual framework

    PubMed Central

    Carayon, Pascale; Hancock, Peter; Leveson, Nancy; Noy, Ian; Sznelwar, Laerte; van Hootegem, Geert

    2015-01-01

    Traditional efforts to deal with the enormous problem of workplace safety have proved insufficient, as they have tended to neglect the broader sociotechnical environment that surrounds workers. Here, we advocate a sociotechnical systems approach that describes the complex multi-level system factors that contribute to workplace safety. From the literature on sociotechnical systems, complex systems and safety, we develop a sociotechnical model of workplace safety with concentric layers of the work system, socio-organisational context and the external environment. The future challenges that are identified through the model are highlighted. Practitioner Summary: Understanding the environmental, organisational and work system factors that contribute to workplace safety will help to develop more effective and integrated solutions to deal with persistent workplace safety problems. Solutions to improve workplace safety need to recognise the broad sociotechnical system and the respective interactions between the system elements and levels. PMID:25831959

  3. Moving the Watershed Ecosystem Approach Beyond the Black Box with Sensor Technologies and New Conceptual Models

    NASA Astrophysics Data System (ADS)

    Bailey, S. W.; McGuire, K. J.; Ross, D. S.

    2015-12-01

    The small watershed ecosystem as a unit of experimental manipulation and analysis has been a hallmark of the Hubbard Brook Experimental Forest for 60 years. Water and nutrient budgets of headwater catchments have been instrumental in advancing our understanding of the response of forested ecosystems to disturbances such as air pollution and land management. A limitation in the practice of this approach is that point-scale measurements are compiled to create catchment scale estimates of fluxes and stores, thus losing process information that could be gained from spatial patterns that depend on position along hydrologic or biogeochemical pathways. Beginning in 2007, high frequency measurements of water table fluctuation, made possible by inexpensive sensor technology, highlighted the previously underappreciated role of groundwater in these steep headwater catchments. Hydropedologic units (HPUs), identified by morphological differences in soil profiles, and reflecting distinct groundwater regimes, were defined and arranged along a generalized toposequence to describe a conceptual model which partitions spatial variation into predictable, repeatable landscape units. Stratification of point scale measurements of soil and water quality elucidates spatial patterns of variation and allows identification of hot spots, or zones of the catchment where certain processes prevail. Specific HPUs are associated with high rates of dissolved organic matter production, nitrification, denitrification and delivery of mineral weathering products to the surface. Moving beyond the small watershed, contrasting spatial patterns in surface water chemistry at the basin scale suggest differing prevalence of various HPUs among headwater catchments. Comparison of water quality patterns with HPU distribution allows identification of catchment properties responsible for regulation of water quality at the point to the catchment to the basin scales.

  4. Recent advances in modeling stellar interiors (u)

    SciTech Connect

    Guzik, Joyce Ann

    2010-01-01

    Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid {gamma} Dor/{delta} Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as {eta} Car and P Cyg, and the solar abundance problem.

  5. Recent advances in modeling stellar interiors

    NASA Astrophysics Data System (ADS)

    Guzik, Joyce Ann

    2011-11-01

    Advances in stellar interior modeling are being driven by new data from large-scale surveys and high-precision photometric and spectroscopic observations. Here we focus on single stars in normal evolutionary phases; we will not discuss the many advances in modeling star formation, interacting binaries, supernovae, or neutron stars. We review briefly: (1) updates to input physics of stellar models; (2) progress in two and three-dimensional evolution and hydrodynamic models; (3) insights from oscillation data used to infer stellar interior structure and validate model predictions (asteroseismology). We close by highlighting a few outstanding problems, e.g., the driving mechanisms for hybrid γ Dor/ δ Sct star pulsations, the cause of giant eruptions seen in luminous blue variables such as η Car and P Cyg, and the solar abundance problem.

  6. Employee commitment and motivation: a conceptual analysis and integrative model.

    PubMed

    Myer, John P; Becker, Thomas E; Vandenberghe, Christian

    2004-12-01

    Theorists and researchers interested in employee commitment and motivation have not made optimal use of each other's work. Commitment researchers seldom address the motivational processes through which commitment affects behavior, and motivation researchers have not recognized important distinctions in the forms, foci, and bases of commitment. To encourage greater cross-fertilization, the authors present an integrative framework in which commitment is presented as one of several energizing forces for motivated behavior. E. A. Locke's (1997) model of the work motivation process and J. P. Meyer and L. Herscovitch's (2001) model of workplace commitments serve as the foundation for the development of this new framework. To facilitate the merger, a new concept, goal regulation, is derived from self-determination theory (E. L. Deci & R. M. Ryan, 1985) and regulatory focus theory (E. I. Higgins, 1997). By including goal regulation, it is acknowledged that motivated behavior can be accompanied by different mindsets that have particularly important implications for the explanation and prediction of discretionary work behavior.

  7. Preliminary conceptual model for mineral evolution in Yucca Mountain

    SciTech Connect

    Duffy, C.J.

    1993-12-01

    A model is presented for mineral alteration in Yucca Mountain, Nevada, that suggests that the mineral transformations observed there are primarily controlled by the activity of aqueous silica. The rate of these reactions is related to the rate of evolution of the metastable silica polymorphs opal-CT and cristobalite assuming that a{sub SiO{sub 2(aq)}} is fixed at the equilibrium solubility of the most soluble silica polymorph present. The rate equations accurately predict the present depths of disappearance of opal-CT and cristobalite. The rate equations have also been used to predict the extent of future mineral alteration that may result from emplacement of a high-level nuclear waste repository in Yucca Mountain. Relatively small changes in mineralogy are predicted, but these predictions are based on the assumption that emplacement of a repository would not increase the pH of water in Yucca Mountain nor increase its carbonate content. Such changes may significantly increase mineral alteration. Some of the reactions currently occurring in Yucca Mountain consume H{sup +} and CO{sub 3}{sup 2{minus}}. Combining reaction rate models for these reactions with water chemistry data may make it possible to estimate water flux through the basal vitrophyre of the Topopah Spring Member and to help confirm the direction and rate of flow of groundwater in Yucca Mountain.

  8. Periodic orbits for a discontinuous vector field arising from a conceptual model of glacial cycles

    NASA Astrophysics Data System (ADS)

    Walsh, James; Widiasih, Esther; Hahn, Jonathan; McGehee, Richard

    2016-06-01

    Conceptual climate models provide an approach to understanding climate processes through a mathematical analysis of an approximation to reality. Recently, these models have also provided interesting examples of nonsmooth dynamical systems. Here we develop a new conceptual model of glacial cycles consisting of a system of three ordinary differential equations defining a discontinuous vector field. Our model provides a dynamical systems framework for a mechanism previously shown to play a crucial role in glacial cycle patterns, namely, an increased ice sheet ablation rate during deglaciations. We use ad hoc singular perturbation techniques to prove the existence of a large periodic orbit crossing the discontinuity boundary, provided the ice sheet edge moves sufficiently slowly relative to changes in the snow line and temperature. Numerical explorations reveal the periodic orbit exists when the time constant for the ice sheet edge has more moderate values.

  9. A year 2003 conceptual model for the U.S. telecommunications infrastructure.

    SciTech Connect

    Cox, Roger Gary; Reinert, Rhonda K.

    2003-12-01

    To model the telecommunications infrastructure and its role and robustness to shocks, we must characterize the business and engineering of telecommunications systems in the year 2003 and beyond. By analogy to environmental systems modeling, we seek to develop a 'conceptual model' for telecommunications. Here, the conceptual model is a list of high-level assumptions consistent with the economic and engineering architectures of telecommunications suppliers and customers, both today and in the near future. We describe the present engineering architectures of the most popular service offerings, and describe the supplier markets in some detail. We also develop a characterization of the customer base for telecommunications services and project its likely response to disruptions in service, base-lining such conjectures against observed behaviors during 9/11.

  10. Three-dimensional conceptual model for the Hanford Site unconfined aquifer system, FY 1993 status report

    SciTech Connect

    Thorne, P.D.; Chamness, M.A.; Spane, F.A. Jr.; Vermeul, V.R.; Webber, W.D.

    1993-12-01

    The ground water underlying parts of the Hanford Site (Figure 1.1) contains radioactive and chemical contaminants at concentrations exceeding regulatory standards (Dresel et al. 1993). The Hanford Site Ground-Water Surveillance Project, operated by Pacific Northwest Laboratory (PNL), is responsible for monitoring the movement of these contaminants to ensure that public health and the environment are protected. To support the monitoring effort, a sitewide three-dimensional ground-water flow model is being developed. This report provides an update on the status of the conceptual model that will form the basis for constructing a numerical three-dimensional flow model for, the site. Thorne and Chamness (1992) provide additional information on the initial development of the three-dimensional conceptual model.

  11. Conceptual ecological models to guide integrated landscape monitoring of the Great Basin

    USGS Publications Warehouse

    Miller, D.M.; Finn, S.P.; Woodward, Andrea; Torregrosa, Alicia; Miller, M.E.; Bedford, D.R.; Brasher, A.M.

    2010-01-01

    The Great Basin Integrated Landscape Monitoring Pilot Project was developed in response to the need for a monitoring and predictive capability that addresses changes in broad landscapes and waterscapes. Human communities and needs are nested within landscapes formed by interactions among the hydrosphere, geosphere, and biosphere. Understanding the complex processes that shape landscapes and deriving ways to manage them sustainably while meeting human needs require sophisticated modeling and monitoring. This document summarizes current understanding of ecosystem structure and function for many of the ecosystems within the Great Basin using conceptual models. The conceptual ecosystem models identify key ecological components and processes, identify external drivers, develop a hierarchical set of models that address both site and landscape attributes, inform regional monitoring strategy, and identify critical gaps in our knowledge of ecosystem function. The report also illustrates an approach for temporal and spatial scaling from site-specific models to landscape models and for understanding cumulative effects. Eventually, conceptual models can provide a structure for designing monitoring programs, interpreting monitoring and other data, and assessing the accuracy of our understanding of ecosystem functions and processes.

  12. Conceptual and numerical models for sustainable groundwater management in the Thaphra area, Chi River Basin, Thailand

    NASA Astrophysics Data System (ADS)

    Nettasana, Tussanee; Craig, James; Tolson, Bryan

    2012-11-01

    Sustainable management of groundwater resources is vital for development of areas at risk from water-resource over-exploitation. In northeast Thailand, the Phu Thok aquifer is an important water source, particularly in the Thaphra area, where increased groundwater withdrawals may result in water-level decline and saline-water upconing. Three-dimensional finite-difference flow models were developed with MODFLOW to predict the impacts of future pumping on hydraulic heads. Four scenarios of pumping and recharge were defined to evaluate the system response to future usage and climate conditions. Primary model simulations show that groundwater heads will continue to decrease by 4-12 m by the year 2040 at the center of the highly exploited area, under conditions of both increasing pumping and drought. To quantify predictive uncertainty in these estimates, in addition to the primary conceptual model, three alternative conceptual models were used in the simulation of sustainable yields. These alternative models show that, for this case study, a reasonable degree of uncertainty in hydrostratigraphic interpretation is more impactful than uncertainty in recharge distribution or boundary conditions. The uncertainty-analysis results strongly support addressing conceptual-model uncertainty in the practice of groundwater-management modeling. Doing so will better assist decision makers in selecting and implementing robust sustainable strategies.

  13. Advances in Scientific Balloon Thermal Modeling

    NASA Technical Reports Server (NTRS)

    Bohaboj, T.; Cathey, H. M., Jr.

    2004-01-01

    The National Aeronautics and Space Administration's Balloon Program office has long acknowledged that the accurate modeling of balloon performance and flight prediction is dependant on how well the balloon is thermally modeled. This ongoing effort is focused on developing accurate balloon thermal models that can be used to quickly predict balloon temperatures and balloon performance. The ability to model parametric changes is also a driver for this effort. This paper will present the most recent advances made in this area. This research effort continues to utilize the "Thrmal Desktop" addition to AUTO CAD for the modeling. Recent advances have been made by using this analytical tool. A number of analyses have been completed to test the applicability of this tool to the problem with very positive results. Progressively detailed models have been developed to explore the capabilities of the tool as well as to provide guidance in model formulation. A number of parametric studies have been completed. These studies have varied the shape of the structure, material properties, environmental inputs, and model geometry. These studies have concentrated on spherical "proxy models" for the initial development stages and then to transition to the natural shaped zero pressure and super pressure balloons. An assessment of required model resolution has also been determined. Model solutions have been cross checked with known solutions via hand calculations. The comparison of these cases will also be presented. One goal is to develop analysis guidelines and an approach for modeling balloons for both simple first order estimates and detailed full models. This papa presents the step by step advances made as part of this effort, capabilities, limitations, and the lessons learned. Also presented are the plans for further thermal modeling work.

  14. What Can Be Learned From a Laboratory Model of Conceptual Change? Descriptive Findings and Methodological Issues

    NASA Astrophysics Data System (ADS)

    Ohlsson, Stellan; Cosejo, David G.

    2014-07-01

    The problem of how people process novel and unexpected information— deep learning (Ohlsson in Deep learning: how the mind overrides experience. Cambridge University Press, New York, 2011)—is central to several fields of research, including creativity, belief revision, and conceptual change. Researchers have not converged on a single theory for conceptual change, nor has any one theory been decisively falsified. One contributing reason is the difficulty of collecting informative data in this field. We propose that the commonly used methodologies of historical analysis, classroom interventions, and developmental studies, although indispensible, can be supplemented with studies of laboratory models of conceptual change. We introduce re- categorization, an experimental paradigm in which learners transition from one definition of a categorical concept to another, incompatible definition of the same concept, a simple form of conceptual change. We describe a re-categorization experiment, report some descriptive findings pertaining to the effects of category complexity, the temporal unfolding of learning, and the nature of the learner's final knowledge state. We end with a brief discussion of ways in which the re-categorization model can be improved.

  15. Conceptualization of Approaches and Thought Processes Emerging in Validating of Model in Mathematical Modeling in Technology Aided Environment

    ERIC Educational Resources Information Center

    Hidiroglu, Çaglar Naci; Bukova Güzel, Esra

    2013-01-01

    The aim of the present study is to conceptualize the approaches displayed for validation of model and thought processes provided in mathematical modeling process performed in technology-aided learning environment. The participants of this grounded theory study were nineteen secondary school mathematics student teachers. The data gathered from the…

  16. SITE CHARACTERIZATION TO SUPPORT DEVELOPMENT OF CONCEPTUAL SITE MODELS AND TRANSPORT MODELS FOR MONITORING CONTAMINANTS IN GROUND WATER

    EPA Science Inventory

    The development of conceptual and predictive models is an important tool to guide site characterization in support of monitoring contaminants in ground water. The accuracy of predictive models is limited by the adequacy of the input data and the assumptions made to constrain mod...

  17. Center for Advanced Modeling and Simulation Intern

    SciTech Connect

    Gertman, Vanessa

    2010-01-01

    Some interns just copy papers and seal envelopes. Not at INL! Check out how Vanessa Gertman, an INL intern working at the Center for Advanced Modeling and Simulation, spent her summer working with some intense visualization software. Lots more content like this is available at INL's facebook page http://www.facebook.com/idahonationallaboratory.

  18. Center for Advanced Modeling and Simulation Intern

    ScienceCinema

    Gertman, Vanessa

    2016-07-12

    Some interns just copy papers and seal envelopes. Not at INL! Check out how Vanessa Gertman, an INL intern working at the Center for Advanced Modeling and Simulation, spent her summer working with some intense visualization software. Lots more content like this is available at INL's facebook page http://www.facebook.com/idahonationallaboratory.

  19. Conceptual modeling of coincident failures in multiversion software

    NASA Technical Reports Server (NTRS)

    Littlewood, Bev; Miller, Douglas R.

    1989-01-01

    Recent work by Eckhardt and Lee (1985) shows that independently developed program versions fail dependently (specifically, simultaneous failure of several is greater than would be the case under true independence). The present authors show there is a precise duality between input choice and program choice in this model and consider a generalization in which different versions can be developed using diverse methodologies. The use of diverse methodologies is shown to decrease the probability of the simultaneous failure of several versions. Indeed, it is theoretically possible to obtain versions which exhibit better than independent failure behavior. The authors try to formalize the notion of methodological diversity by considering the sequence of decision outcomes that constitute a methodology. They show that diversity of decision implies likely diversity of behavior for the different verions developed under such forced diversity. For certain one-out-of-n systems the authors obtain an optimal method for allocating diversity between versions. For two-out-of-three systems there seem to be no simple optimality results which do not depend on constraints which cannot be verified in practice.

  20. Community Elder Mistreatment Intervention With Capable Older Adults: Toward a Conceptual Practice Model.

    PubMed

    Burnes, David

    2016-02-12

    Community-based elder mistreatment response programs (EMRP), such as adult protective services, that are responsible for directly addressing elder abuse and neglect are under increasing pressure with greater reporting/referrals nationwide. Our knowledge and understanding of effective response interventions represents a major gap in the EM literature. At the center of this gap is a lack of theory or conceptual models to help guide EMRP research and practice. This article develops a conceptual practice model for community-based EMRPs that work directly with cognitively intact EM victims. Anchored by core EMRP values of voluntariness, self-determination, and least restrictive path, the practice model is guided by an overarching postmodern, constructivist, eco-systemic practice paradigm that accepts multiple, individually constructed mistreatment realities and solutions. Harm-reduction, client-centered, and multidisciplinary practice models are described toward a common EMRP goal to reduce the risk of continued mistreatment. Finally, the model focuses on client-practitioner relationship-oriented practice skills such as engagement and therapeutic alliance to elicit individual mistreatment realities and client-centered solutions. The practice model helps fill a conceptual gap in the EM intervention literature and carries implications for EMRP training, research, and practice.

  1. The EBM-DPSER conceptual model: integrating ecosystem services into the DPSIR framework.

    PubMed

    Kelble, Christopher R; Loomis, Dave K; Lovelace, Susan; Nuttle, William K; Ortner, Peter B; Fletcher, Pamela; Cook, Geoffrey S; Lorenz, Jerry J; Boyer, Joseph N

    2013-01-01

    There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within

  2. The EBM-DPSER Conceptual Model: Integrating Ecosystem Services into the DPSIR Framework

    PubMed Central

    Kelble, Christopher R.; Loomis, Dave K.; Lovelace, Susan; Nuttle, William K.; Ortner, Peter B.; Fletcher, Pamela; Cook, Geoffrey S.; Lorenz, Jerry J.; Boyer, Joseph N.

    2013-01-01

    There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within

  3. Groundwater modelling in decision support: reflections on a unified conceptual framework

    NASA Astrophysics Data System (ADS)

    Doherty, John; Simmons, Craig T.

    2013-11-01

    Groundwater models are commonly used as basis for environmental decision-making. There has been discussion and debate in recent times regarding the issue of model simplicity and complexity. This paper contributes to this ongoing discourse. The selection of an appropriate level of model structural and parameterization complexity is not a simple matter. Although the metrics on which such selection should be based are simple, there are many competing, and often unquantifiable, considerations which must be taken into account as these metrics are applied. A unified conceptual framework is introduced and described which is intended to underpin groundwater modelling in decision support with a direct focus on matters regarding model simplicity and complexity.

  4. A conceptual model of ocean freshwater flux derived from sea surface salinity

    NASA Astrophysics Data System (ADS)

    Nieves, V.; Wang, J.; Willis, J. K.

    2014-09-01

    A conceptual model is proposed to express freshwater flux (evaporation minus precipitation) as a function of sea surface salinity (and vice versa). The model is formulated using an idealized one-dimensional diffusion equation for the ocean surface layer. It is shown to provide good agreement with existing freshwater flux estimates and salinity observations. It also has the potential to enhance our capability of monitoring and modeling global freshwater fluxes and salinity as a data retrieval algorithm for remote sensing. The model may improve physical parameterization in coupled ocean-atmosphere models to study the global water cycle.

  5. Understanding and using informants' reporting discrepancies of youth victimization: a conceptual model and recommendations for research.

    PubMed

    Goodman, Kimberly L; De Los Reyes, Andres; Bradshaw, Catherine P

    2010-12-01

    Discrepancies often occur among informants' reports of various domains of child and family functioning and are particularly common between parent and child reports of youth violence exposure. However, recent work suggests that discrepancies between parent and child reports predict subsequent poorer child outcomes. We propose a preliminary conceptual model (Discrepancies in Victimization Implicate Developmental Effects [DiVIDE]) that considers how and why discrepancies between parents' and youths' ratings of child victimization may be related to poor adjustment outcomes. The model addresses how dyadic processes, such as the parent-youth relationship and youths' information management, might contribute to discrepancies. We also consider coping processes that explain why discrepancies may predict increases in youth maladjustment. Based on this preliminary conceptual framework, we offer suggestions and future directions for researchers who encounter conflicting reports of community violence exposure and discuss why the proposed model is relevant to interventions for victimized youths.

  6. Conceptual model of iCAL4LA: Proposing the components using comparative analysis

    NASA Astrophysics Data System (ADS)

    Ahmad, Siti Zulaiha; Mutalib, Ariffin Abdul

    2016-08-01

    This paper discusses an on-going study that initiates an initial process in determining the common components for a conceptual model of interactive computer-assisted learning that is specifically designed for low achieving children. This group of children needs a specific learning support that can be used as an alternative learning material in their learning environment. In order to develop the conceptual model, this study extracts the common components from 15 strongly justified computer assisted learning studies. A comparative analysis has been conducted to determine the most appropriate components by using a set of specific indication classification to prioritize the applicability. The results of the extraction process reveal 17 common components for consideration. Later, based on scientific justifications, 16 of them were selected as the proposed components for the model.

  7. Conceptual Incoherence as a Result of the use of Multiple Historical Models in School Textbooks

    NASA Astrophysics Data System (ADS)

    Gericke, Niklas M.; Hagberg, Mariana

    2010-08-01

    This paper explores the occurrence of conceptual incoherence in upper secondary school textbooks resulting from the use of multiple historical models. Swedish biology and chemistry textbooks, as well as a selection of books from English speaking countries, were examined. The purpose of the study was to identify which models are used to represent the phenomenon of gene function in textbooks and to investigate how these models relate to historical scientific models and subject matter contexts. Models constructed for specific use in textbooks were identified using concept mapping. The data were further analyzed by content analysis. The study shows that several different historical models are used in parallel in textbooks to describe gene function. Certain historical models were used more often then others and the most recent scientific views were rarely referred to in the textbooks. Hybrid models were used frequently, i.e. most of the models in the textbooks consisted of a number of components of several historical models. Since the various historical models were developed as part of different scientific frameworks, hybrid models exhibit conceptual incoherence, which may be a source of confusion for students. Furthermore, the use of different historical models was linked to particular subject contexts in the textbooks studied. The results from Swedish and international textbooks were similar, indicating the general applicability of our conclusions.

  8. Simulating runoff under changing climatic conditions: Revisiting an apparent deficiency of conceptual rainfall-runoff models

    NASA Astrophysics Data System (ADS)

    Fowler, Keirnan J. A.; Peel, Murray C.; Western, Andrew W.; Zhang, Lu; Peterson, Tim J.

    2016-03-01

    Hydrologic models have potential to be useful tools in planning for future climate variability. However, recent literature suggests that the current generation of conceptual rainfall runoff models tend to underestimate the sensitivity of runoff to a given change in rainfall, leading to poor performance when evaluated over multiyear droughts. This research revisited this conclusion, investigating whether the observed poor performance could be due to insufficient model calibration and evaluation techniques. We applied an approach based on Pareto optimality to explore trade-offs between model performance in different climatic conditions. Five conceptual rainfall runoff model structures were tested in 86 catchments in Australia, for a total of 430 Pareto analyses. The Pareto results were then compared with results from a commonly used model calibration and evaluation method, the Differential Split Sample Test. We found that the latter often missed potentially promising parameter sets within a given model structure, giving a false negative impression of the capabilities of the model. This suggests that models may be more capable under changing climatic conditions than previously thought. Of the 282[347] cases of apparent model failure under the split sample test using the lower [higher] of two model performance criteria trialed, 155[120] were false negatives. We discuss potential causes of remaining model failures, including the role of data errors. Although the Pareto approach proved useful, our aim was not to suggest an alternative calibration strategy, but to critically assess existing methods of model calibration and evaluation. We recommend caution when interpreting split sample results.

  9. Ecohydrologic Response of a Wetland Indicator Species to Climate Change and Streamflow Regulation: A Conceptual Model

    NASA Astrophysics Data System (ADS)

    Ward, E. M.; Gorelick, S.

    2015-12-01

    The Peace-Athabasca Delta ("Delta") in northeastern Alberta, Canada, is a UNESCO World Heritage Site and a Ramsar Wetland of International Importance. Delta ecohydrology is expected to respond rapidly to upstream water demand and climate change, with earlier spring meltwater, decreased springtime peak flow, and a decline in springtime ice-jam flooding. We focus on changes in the population and distribution of muskrat (Ondatra zibethicus), an ecohydrologic indicator species. We present a conceptual model linking hydrology and muskrat ecology. Our conceptual model links seven modules representing (1) upstream water demand, (2) streamflow and snowmelt, (3) floods, (4) the water balance of floodplain lakes, (5) muskrat habitat suitability, (6) wetland vegetation, and (7) muskrat population dynamics predicted using an agent-based model. Our goal is to evaluate the effects of different climate change and upstream water demand scenarios on the abundance and distribution of Delta muskrat, from present-2100. Moving from the current conceptual model to a predictive quantitative model, we will rely on abundant existing data and Traditional Ecological Knowledge of muskrat and hydrology in the Delta.

  10. Understanding hydrological flow paths in conceptual catchment models using uncertainty and sensitivity analysis

    NASA Astrophysics Data System (ADS)

    Mockler, Eva M.; O'Loughlin, Fiachra E.; Bruen, Michael

    2016-05-01

    Increasing pressures on water quality due to intensification of agriculture have raised demands for environmental modeling to accurately simulate the movement of diffuse (nonpoint) nutrients in catchments. As hydrological flows drive the movement and attenuation of nutrients, individual hydrological processes in models should be adequately represented for water quality simulations to be meaningful. In particular, the relative contribution of groundwater and surface runoff to rivers is of interest, as increasing nitrate concentrations are linked to higher groundwater discharges. These requirements for hydrological modeling of groundwater contribution to rivers initiated this assessment of internal flow path partitioning in conceptual hydrological models. In this study, a variance based sensitivity analysis method was used to investigate parameter sensitivities and flow partitioning of three conceptual hydrological models simulating 31 Irish catchments. We compared two established conceptual hydrological models (NAM and SMARG) and a new model (SMART), produced especially for water quality modeling. In addition to the criteria that assess streamflow simulations, a ratio of average groundwater contribution to total streamflow was calculated for all simulations over the 16 year study period. As observations time-series of groundwater contributions to streamflow are not available at catchment scale, the groundwater ratios were evaluated against average annual indices of base flow and deep groundwater flow for each catchment. The exploration of sensitivities of internal flow path partitioning was a specific focus to assist in evaluating model performances. Results highlight that model structure has a strong impact on simulated groundwater flow paths. Sensitivity to the internal pathways in the models are not reflected in the performance criteria results. This demonstrates that simulated groundwater contribution should be constrained by independent data to ensure results

  11. Maturity Model for Advancing Smart Grid Interoperability

    SciTech Connect

    Knight, Mark; Widergren, Steven E.; Mater, J.; Montgomery, Austin

    2013-10-28

    Abstract—Interoperability is about the properties of devices and systems to connect and work properly. Advancing interoperability eases integration and maintenance of the resulting interconnection. This leads to faster integration, lower labor and component costs, predictability of projects and the resulting performance, and evolutionary paths for upgrade. When specifications are shared and standardized, competition and novel solutions can bring new value streams to the community of stakeholders involved. Advancing interoperability involves reaching agreement for how things join at their interfaces. The quality of the agreements and the alignment of parties involved in the agreement present challenges that are best met with process improvement techniques. The GridWise® Architecture Council (GWAC) sponsored by the United States Department of Energy is supporting an effort to use concepts from capability maturity models used in the software industry to advance interoperability of smart grid technology. An interoperability maturity model has been drafted and experience is being gained through trials on various types of projects and community efforts. This paper describes the value and objectives of maturity models, the nature of the interoperability maturity model and how it compares with other maturity models, and experiences gained with its use.

  12. Seepage weathering impacts on erosivity of arid stream banks: A new conceptual model

    NASA Astrophysics Data System (ADS)

    Nachshon, Uri

    2016-05-01

    Field observations have indicated the formation of horizontal, pipe shape cavities, along gully and dry stream channel banks in the semi-arid region of the northern Negev Desert, Israel. Piping is a well-known phenomenon in humid regions due to subsurface water flow and seepage weathering. However, in dry environments where rain events are scarce and subsurface water flow is rare, it is proposed here that capillary flow of saline water in the vadose zone leads to similar processes. It is suggested that where saline and shallow ground water persists, capillary flow may result in salt accumulation and precipitation at the top of the capillary fringe, consequently rendering this zone to be more susceptible to erosion. A conceptual model is presented and field observations, laboratory experiments, and a physically-based model are used to prove the feasibility of the proposed conceptual model and to explain why salts accumulate at the top of the capillary fringe, even though evaporation acts all along the vertical stream channel or gully banks. It is suggested that the low evaporative flux, in comparison to the liquid water flux, disables salt accumulation along the profile to the top of the capillary fringe where the liquid water flux is minimal. The presented findings strengthen the conceptual model, but thorough field studies are needed to estimate the impact of the proposed mechanism on erosion processes on a field scale.

  13. What is a health expectation? Developing a pragmatic conceptual model from psychological theory

    PubMed Central

    Janzen, Jennifer Amy; Silvius, James; Jacobs, Sarah; Slaughter, Susan; Dalziel, William; Drummond, Neil

    2006-01-01

    Abstract Introduction  Examination of the existing literature in respect of health expectations revealed both ambiguity in relation to terminology, and relatively little work in respect of how abstract theories of expectancy in the psychological literature might be used in empirical research into the influence of expectations on attitudes and behaviours in the real world. This paper presents a conceptual model for the development of health expectations with specific reference to Alzheimer's disease. Method  Literature review, synthesis and conceptual model development, illustrated by the case of a person with newly diagnosed, early‐stage Alzheimer's disease, and her caregiver. Outcome  Our model envisages the development of a health expectation as incorporating several longitudinal phases (precipitating phenomenon, prior understanding, cognitive processing, expectation formulation, outcome, post‐outcome cognitive processing). Conclusion  Expectations are a highly important but still relatively poorly understood phenomenon in relation to the experience of health and health care. We suggest a pragmatic conceptual model designed to clarify the process of expectation development, in order to inform future research into the measurement of health expectations and to enhance our understanding of the influence of expectations on health behaviours and attitudes. PMID:16436160

  14. On Correct Likelihoods and Model Combinations: A Bayesian Multi-Model Conceptual Framework for Structural Uncertainty Assessment

    NASA Astrophysics Data System (ADS)

    Mehrotra, R.; Smith, T. J.; Sharma, A.; Marshall, L. A.

    2010-12-01

    The use of data in conceptual hydrologic modeling applications typically occurs on two levels; model driving data/input data (precipitation, evapotranspiration) and model checking data/output data (observed stream outlet discharge). However, the uncertainty of these data limits their ability to inform the choice of a “true” model structure. In this research, we present a framework approach that focuses on the intersect of two primary areas for improved assessment of model structures and their uncertainty: (1) an investigation into multiple model conceptualizations for structural uncertainty assessment and (2) an examination of the use of formal likelihood functions under a Bayesian statistical approach. The use of formal Bayesian methodologies for hydrologic model parameter estimation and uncertainty analysis is predicated on the selection of an adequate likelihood function, which makes strong assumptions about the form of the model residuals. By better addressing this area of the modeling problem, the analysis of the model structural uncertainty in light of the traditional data sources (precipitation, evapotranspiration, stream discharge) is simplified. In concert with the effort to more appropriately apply the Bayesian approach, the use of multiple conceptual model structures into the analysis deals directly with the objective of better quantifying model structural uncertainty. Previous studies that have addressed the structural uncertainty issue from a multiple model vantage point have found promising results. The findings of this study suggest that improved statistical inference brought about by careful attention to the assumptions of the formal likelihood function combined with analysis of multiple model conceptualizations have the potential to afford a better understanding of model structural uncertainty. An intended outcome of this research, and part of future study, is to produce techniques that prove beneficial for use in regionalization studies for

  15. Aeroheating model advancements featuring electroless metallic plating

    NASA Technical Reports Server (NTRS)

    Stalmach, C. J., Jr.; Goodrich, W. D.

    1976-01-01

    Discussed are advancements in wind tunnel model construction methods and hypersonic test data demonstrating the methods. The general objective was to develop model fabrication methods for improved heat transfer measuring capability at less model cost. A plated slab model approach was evaluated with cast models containing constantan wires that formed single-wire-to-plate surface thermocouple junctions with a seamless skin of electroless nickel alloy. The surface of a space shuttle orbiter model was selectively plated with scaled tiles to simulate, with high fidelity, the probable misalignments of the heatshield tiles on a flight vehicle. Initial, Mach 8 heating results indicated a minor effect of tile misalignment roughness on boundary layer transition, implying a possible relaxation of heatshield manufacturing tolerances. Some loss of the plated tiles was experienced when the model was tested at high heating rates.

  16. Development of a conceptual model of the role of hospital nurses in health promotion in Jordan.

    PubMed

    Shoqirat, N

    2015-05-19

    International evidence reveals that hospital nurses have not been able to incorporate health promotion effectively into the framework of their care. This can be attributed to unclear conceptualizing of the barriers and facilitators to the role of nurses in health promotion. An integrative review was carried out to develop a conceptual model to assist hospital nurses in Jordan to understand how health promotion activities can be developed. Factors affecting the involvement of nurses in health promotion - ranging from limited knowledge about health promotion to the social image of nursing - can be structured into three levels: the micro (individual), meso (organizational) and macro (population). By understanding the interplay of factors between and within the levels, nurses and other health professionals can draw on the individual, social and organizational factors that influence nurses' role in health promotion. The proposed model can be considered as a springboard for developing health promotion activities related to hospitals in other Muslim-majority contexts.

  17. A conceptual model to facilitate amphibian conservation in the northern Great Plains

    USGS Publications Warehouse

    Mushnet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa.

  18. Mercury Issues and Complexities in Oak Ridge, Tennessee; Redefining the Conceptual Model - 12277

    SciTech Connect

    Peterson, Mark; Southworth, George; Watson, David; Looney, Brian; Eddy-Dilek, Carol; Ketelle, Richard

    2012-07-01

    Releases of mercury from an industrial facility in Oak Ridge, Tennessee in the 1950's and early 1960's resulted in contamination of soil and groundwater within the facility, as well as downstream surface waters. Remediation efforts, which began in the 1980's, have decreased waterborne mercury concentrations near the facility, but elevated levels of mercury remain in the soil, sediment, water, and biota. Widespread distribution of mercury sources and complex mercury transport pathways are some of many challenges at the site. For effective environmental management and closure decision making relative to mercury contamination at the facilities, an up-to-date conceptual model of mercury source areas, processes, likely flow paths, and flux was deemed necessary. Recent facility and reconfiguration efforts, site characterizations, remedial actions, and research are facilitating the collection of new mercury data in Oak Ridge. To develop the current model, a multi-organizational team reviewed existing conceptual models from a variety of sources, consolidated historical data and source information, gathered input from local experts with extensive site knowledge, and used recently collected mercury data from a variety of sampling programs. The developed site conceptual model indicates that the nature and extent of mercury concentration and contaminant flux has significantly changed in the ten years since flux-based conceptual models were used for previous remedial action decisions. A new water treatment system has effectively reduced mercury inputs to the creek and is removing substantially greater quantities of mercury from groundwater than was expected. However, fish concentrations in downstream waters have not responded to decreased water concentrations in the stream. Flux from one large out-fall at the creek's headwaters appears to be a greater percentage of the overall flux leaving the site than previous years, albeit year to year variation in flux is large, and the

  19. Evaluating and Refining the Conceptual Model Used in the Study of Health and Activity in Preschool Environments (SHAPES) Intervention.

    PubMed

    Saunders, Ruth P; Pfeiffer, Karin; Brown, William H; Howie, Erin K; Dowda, Marsha; O'Neill, Jennifer R; McIver, Kerry; Pate, Russell R

    2017-01-01

    This study investigated the utility of the Study of Health and Activity in Preschool Environments (SHAPES) conceptual model, which targeted physical activity (PA) behavior in preschool children, by examining the relationship between implementation monitoring data and child PA during the school day. We monitored implementation completeness and fidelity based on multiple elements identified in the conceptual model. Comparing high-implementing, low-implementing, and control groups revealed no association between implementation and outcomes. We performed post hoc analyses, using process data, to refine our conceptual model's depiction of an effective preschool PA-promoting environment. Results suggest that a single component of the original four-component conceptual model, providing opportunities for moderate-to-vigorous physical activity through recess for 4-year-old children in preschool settings, may be a good starting place for increasing moderate-to-vigorous physical activity. Interventions that are implemented with optimal levels of completeness and fidelity are more likely to achieve behavior change if they are based on accurate conceptual models. Examining the mechanisms through which an intervention produces its effects, as articulated in the conceptual model that guides it, is particularly important for environmentally focused interventions because they are guided by emerging frameworks. The results of this study underscore the utility of using implementation monitoring data to examine the conceptual model on which the intervention is based.

  20. Conceptual Advances in Paleontology.

    ERIC Educational Resources Information Center

    Tiffney, Bruce Haynes

    1988-01-01

    Suggests ways to overcome the perception by some people that plants are less understood and interesting than invertebrates or vertebrates. Describes the specialization of reproductive systems and the development of plant-animal interactions to help raise the awareness level of the fossil record of plants. (RT)

  1. Conceptual model of groundwater and river water interactions in Cikapundung riverbank, Bandung, West Java

    NASA Astrophysics Data System (ADS)

    Darul, Achmad; Irawan, Dasapta Erwin; Joko Trilaksono, Nurjanna; Pratama, Aditya; Rizki Fitria, Ulfi

    2016-01-01

    Cikapundung river holds a very strategic role as one of the water supply source for Bandung, but the water quality is decreasing over the years. This degradation has also influenced the groundwater in its riverbank. This paper discusses our effor to build a conceptual model to reconstruct previous analytical model which was built in 1997. The base map was built using a total of 32 scenes of WorldView-2 image, combined with Aster image. The dimension of the model was one layer model with elevation (Z) 400 to 2200 m, 361 rows and 454 columns, covering the area of 21.6 x 27.2 km2. Two types of property hydrogeology were defined based on the existing geological maps: Volcanic breccias and, Sand and clay intercalations. The parameterization of the stream was divided into two segments: Curug Dago to Viaduct, Viaduct to Dayeuhkolot. Initial head were observed at: 17 dug wells, 24 river points, and two spring points in 2013. All parameters accommodated by software SWS visual MODFLOW flex 2012 that used three-dimension mathematic equation in steady state to build a conceptual model. Model has been calibrated and showed an appropriateness with dug wells and springs with correlation coefficient of 0.92 and water balance in 0.01 steady state condition (2040 m3).The conceptual model successfully replicates the previous analytical model, showing three segments of water interactions: no flow at segment Maribaya to Curug Dago, combination of effluent and influent flow at segment Curug Dago to Viaduct, and influent flow Viaduct to Dayeuhkolot. However, the model shows some local variations that was not spotted in the previous model.

  2. Precipitation-centered Conceptual Model for Sub-humid Uplands in Lampasas Cut Plains, TX

    NASA Astrophysics Data System (ADS)

    Potter, S. R.; Tu, M.; Wilcox, B. P.

    2011-12-01

    Conceptual understandings of dominant hydrological processes, system interactions and feedbacks, and external forcings operating within catchments often defy simple definition and explanation, especially catchments encompassing transition zones, degraded landscapes, rapid development, and where climate forcings exhibit large variations across time and space. However, it is precisely those areas for which understanding and knowledge are most needed to innovate sustainable management strategies and counter past management blunders and failed restoration efforts. The cut plain of central Texas is one such area. Complex geographic and climatic factors lead to spatially and temporally variable precipitation having frequent dry periods interrupted by intense high-volume precipitation. Fort Hood, an army post located in the southeast cut plain contains landscapes ranging from highly degraded to nearly pristine with a topography mainly comprised of flat-topped mesas separated by broad u-shaped valleys. To understand the hydrology of the area and responses to wet-dry cycles we analyzed 4-years of streamflow and rainfall from 8 catchments, sized between 1819 and 16,000 ha. Since aquifer recharge/discharge and surface stream-groundwater interactions are unimportant, we hypothesized a simple conceptual model driven by precipitation and radiative forcings and having stormflow, baseflow, ET, and two hypothetical storage components. The key storage component was conceptualized as a buffer that was highly integrated with the ET component and exerted controls on baseflow. Radiative energy controlled flux from the buffer to ET. We used the conceptual model in making a bimonthly hydrologic budget, which included buffer volumes and a deficit-surplus indicator. Through the analysis, we were led to speculate that buffer capacity plays key roles in these landscapes and even relatively minor changes in capacity, due to soil compaction for example, might lead to ecological shifts. The

  3. Constructing a Conceptual Model Linking Drivers and Ecosystem Services in Piedmont Streams

    DTIC Science & Technology

    2011-04-01

    CONSTRUCTING A CONCEPTUAL MODEL LINKING DRIVERS AND ECOSYSTEM SERVICES IN PIEDMONT STREAMS S . Kyle McKay1, Bruce A. Pruitt1, Christopher J...5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7...PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) U.S. Army Engineer Research and Development Center,Athens,GA,30606 8. PERFORMING ORGANIZATION REPORT NUMBER

  4. Integration of the Total Lightning Jump Algorithm into Current Operational Warning Environment Conceptual Models

    NASA Technical Reports Server (NTRS)

    Schultz, Chris; Carey, Larry; Schultz, Elise V.; Stano, Geoffrey; Gatlin, Patrick N.; Kozlowski, Danielle M.; Blakeslee, Rich J.; Goodman, Steve

    2013-01-01

    Key points this analysis will address: 1) What physically is going on in the cloud when there is a jump in lightning? -- Updraft variations, Ice fluxes 2) How do these processes fit in with severe storm conceptual models? 3) What would this information provide an end user? --Relate LJA to radar observations, like changes in reflectivity, MESH, VIL, etc. based multi -Doppler derived physical relationships

  5. Developing Conceptual Models for Assessing Climate Change Impacts to Contaminant Availability in Terrestrial Ecosystems

    DTIC Science & Technology

    2015-03-01

    Approved for public release; distribution is unlimited. ERDC/EL TN-15-1 March 2015 Developing Conceptual Models for Assessing Climate Change ...aspects of climate change can impact contaminant availability and threatened, endangered, and at-risk species (TER-S) of terrestrial habitats on military...installations. The goal was to develop tools that aid installation managers with better managing climate change impacts. The CMs can be used as a

  6. Conceptual ecological models to support detection of ecological change on Alaska National Wildlife Refuges

    USGS Publications Warehouse

    Woodward, Andrea; Beever, Erik A.

    2011-01-01

    More than 31 million hectares of land are protected and managed in 16 refuges by the U.S. Fish and Wildlife Service (USFWS) in Alaska. The vastness and isolation of Alaskan refuges give rise to relatively intact and complete ecosystems. The potential for these lands to provide habitat for trust species is likely to be altered, however, due to global climate change, which is having dramatic effects at high latitudes. The ability of USFWS to effectively manage these lands in the future will be enhanced by a regional inventory and monitoring program that integrates and supplements monitoring currently being implemented by individual refuges. Conceptual models inform monitoring programs in a number of ways, including summarizing important ecosystem components and processes as well as facilitating communication, discussion and debate about the nature of the system and important management issues. This process can lead to hypotheses regarding future changes, likely results of alternative management actions, identification of monitoring indicators, and ultimately, interpretation of monitoring results. As a first step towards developing a monitoring program, the 16 refuges in Alaska each created a conceptual model of their refuge and the landscape context. Models include prominent ecosystem components, drivers, and processes by which components are linked or altered. The Alaska refuge system also recognizes that designing and implementing monitoring at regional and ecoregional extents has numerous scientific, fiscal, logistical, and political advantages over monitoring conducted exclusively at refuge-specific scales. Broad-scale monitoring is particularly advantageous for examining phenomena such as climate change because effects are best interpreted at broader spatial extents. To enable an ecoregional perspective, a rationale was developed for deriving ecoregional boundaries for four ecoregions (Polar, Interior Alaska, Bering Coast, and North Pacific Coast) from the

  7. The Persuasion Model of conceptual change and its application to misconceptions in evolution

    NASA Astrophysics Data System (ADS)

    Garner, Joanna Kate

    Previous work has attempted to account for the factors involved in conceptual change (e.g. Posner, Strike, Hewson & Gertzog, 1982; Pintrich, Marx & Boyle, 1993). While progress has been made, cognitive restructuring remains to be positioned within a unifying theory of change. Here, a new model of conceptual change is put forward. The Persuasion Model of conceptual change builds on previous frameworks (Posner, Strike, Hewson & Gertzog, 1982; Pintrich, Marx & Boyle, 1993; Vosniadou, 1994) including the psychology of persuasion (Heuristic-Systematic Model, Chaiken, 1980; Elaboration Likelihood Model, Petty & Cacioppo, 1986; Social Judgement Theory, Sherif & Hovland, 1953) and cognitive and motivational theories of learning (Johnson-Laird, 1983; Mayer & Moreno, 1988; Wittrock, 1974b). High quality, elaborative processing of a persuasive message leads to change. Mental models are positioned as the mechanism by which meaning is created, manipulated, inspected and evaluated. These processes result in a continuum of cognitive restructuring. A study of conceptual change in Evolutionary Biology examined the viability of the Persuasion Model. It was predicted that knowledge, beliefs, interest and cognitive style would predict elaborative processing. Processing was hypothesized to influence information comprehensibility, plausibility, fruitfulness and compatibility with prior knowledge. Judgments were hypothesized to influence learning outcomes. Evolutionary knowledge and beliefs were assessed at pre- and posttest in 375 college students using multiple choice, likert-scale and extended response items. Need for Cognition, Need for Cognitive Closure, Epistemological Beliefs, Religiosity, Dogmatism, Moral Values and Argument Evaluation Ability were measured using paper-and-pencil questionnaires. Participants read a text and indicated elaborative processing and information evaluation. Ninety percent of participants held at least one misconception at pre-test. Significant gains on

  8. The SEM Risk Behavior (SRB) Model: A New Conceptual Model of how Pornography Influences the Sexual Intentions and HIV Risk Behavior of MSM

    PubMed Central

    Wilkerson, J. Michael; Iantaffi, Alex; Smolenski, Derek J.; Brady, Sonya S.; Horvath, Keith J.; Grey, Jeremy A.; Rosser, B. R. Simon

    2012-01-01

    While the effects of sexually explicit media (SEM) on heterosexuals’ sexual intentions and behaviors have been studied, little is known about the consumption and possible influence of SEM among men who have sex with men (MSM). Importantly, conceptual models of how Internet-based SEM influences behavior are lacking. Seventy-nine MSM participated in online focus groups about their SEM viewing preferences and sexual behavior. Twenty-three participants reported recent exposure to a new behavior via SEM. Whether participants modified their sexual intentions and/or engaged in the new behavior depended on three factors: arousal when imagining the behavior, pleasure when attempting the behavior, and trust between sex partners. Based on MSM’s experience, we advance a model of how viewing a new sexual behavior in SEM influences sexual intentions and behaviors. The model includes five paths. Three paths result in the maintenance of sexual intentions and behaviors. One path results in a modification of sexual intentions while maintaining previous sexual behaviors, and one path results in a modification of both sexual intentions and behaviors. With this model, researchers have a framework to test associations between SEM consumption and sexual intentions and behavior, and public health programs have a framework to conceptualize SEM-based HIV/STI prevention programs. PMID:23185126

  9. Advanced Technology System Scheduling Governance Model

    SciTech Connect

    Ang, Jim; Carnes, Brian; Hoang, Thuc; Vigil, Manuel

    2015-06-11

    In the fall of 2005, the Advanced Simulation and Computing (ASC) Program appointed a team to formulate a governance model for allocating resources and scheduling the stockpile stewardship workload on ASC capability systems. This update to the original document takes into account the new technical challenges and roles for advanced technology (AT) systems and the new ASC Program workload categories that must be supported. The goal of this updated model is to effectively allocate and schedule AT computing resources among all three National Nuclear Security Administration (NNSA) laboratories for weapons deliverables that merit priority on this class of resource. The process outlined below describes how proposed work can be evaluated and approved for resource allocations while preserving high effective utilization of the systems. This approach will provide the broadest possible benefit to the Stockpile Stewardship Program (SSP).

  10. Development and testing of a fast conceptual river water quality model.

    PubMed

    Keupers, Ingrid; Willems, Patrick

    2017-04-15

    Modern, model based river quality management strongly relies on river water quality models to simulate the temporal and spatial evolution of pollutant concentrations in the water body. Such models are typically constructed by extending detailed hydrodynamic models with a component describing the advection-diffusion and water quality transformation processes in a detailed, physically based way. This approach is too computational time demanding, especially when simulating long time periods that are needed for statistical analysis of the results or when model sensitivity analysis, calibration and validation require a large number of model runs. To overcome this problem, a structure identification method to set up a conceptual river water quality model has been developed. Instead of calculating the water quality concentrations at each water level and discharge node, the river branch is divided into conceptual reservoirs based on user information such as location of interest and boundary inputs. These reservoirs are modelled as Plug Flow Reactor (PFR) and Continuously Stirred Tank Reactor (CSTR) to describe advection and diffusion processes. The same water quality transformation processes as in the detailed models are considered but with adjusted residence times based on the hydrodynamic simulation results and calibrated to the detailed water quality simulation results. The developed approach allows for a much faster calculation time (factor 10(5)) without significant loss of accuracy, making it feasible to perform time demanding scenario runs.

  11. A conceptual model of psychosomatic illness in children. Family organization and family therapy.

    PubMed

    Minuchin, S; Baker, L; Rosman, B L; Liebman, R; Milman, L; Todd, T C

    1975-08-01

    Linear and open systems (multiple feedback) models of psychosomatic illness in children are contrasted in terms of their implications for cause and treatment. An open systems family model is presented that describes three necessary (but not independently sufficient) conditions for the development and maintenance of severe psychosomatic problems in children: (1) a certain type of family organization that encourages somatization; (2) involvement of the child in parental conflict; and (3) physiological vulnerability. Predisposition for psychosomatic illness, symptom choice, and maintenance are discussed within this conceptual framework. We report on family therapy strategies based on this model and the results of family treatment with 48 cases of "brittle" diabetes, psychosomatic asthma, and anorexia nervosa.

  12. Combustion modeling in advanced gas turbine systems

    SciTech Connect

    Smoot, L.D.; Hedman, P.O.; Fletcher, T.H.

    1995-10-01

    The goal of the U.S. Department of Energy`s Advanced Turbine Systems (ATS) program is to help develop and commercialize ultra-high efficiency, environmentally superior, and cost competitive gas turbine systems for base-load applications in the utility, independent power producer, and industrial markets. Combustion modeling, including emission characteristics, has been identified as a needed, high-priority technology by key professionals in the gas turbine industry.

  13. Unitary Transformations in the Quantum Model for Conceptual Conjunctions and Its Application to Data Representation

    PubMed Central

    Veloz, Tomas; Desjardins, Sylvie

    2015-01-01

    Quantum models of concept combinations have been successful in representing various experimental situations that cannot be accommodated by traditional models based on classical probability or fuzzy set theory. In many cases, the focus has been on producing a representation that fits experimental results to validate quantum models. However, these representations are not always consistent with the cognitive modeling principles. Moreover, some important issues related to the representation of concepts such as the dimensionality of the realization space, the uniqueness of solutions, and the compatibility of measurements, have been overlooked. In this paper, we provide a dimensional analysis of the realization space for the two-sector Fock space model for conjunction of concepts focusing on the first and second sectors separately. We then introduce various representation of concepts that arise from the use of unitary operators in the realization space. In these concrete representations, a pair of concepts and their combination are modeled by a single conceptual state, and by a collection of exemplar-dependent operators. Therefore, they are consistent with cognitive modeling principles. This framework not only provides a uniform approach to model an entire data set, but, because all measurement operators are expressed in the same basis, allows us to address the question of compatibility of measurements. In particular, we present evidence that it may be possible to predict non-commutative effects from partial measurements of conceptual combinations. PMID:26617556

  14. Unitary Transformations in the Quantum Model for Conceptual Conjunctions and Its Application to Data Representation.

    PubMed

    Veloz, Tomas; Desjardins, Sylvie

    2015-01-01

    Quantum models of concept combinations have been successful in representing various experimental situations that cannot be accommodated by traditional models based on classical probability or fuzzy set theory. In many cases, the focus has been on producing a representation that fits experimental results to validate quantum models. However, these representations are not always consistent with the cognitive modeling principles. Moreover, some important issues related to the representation of concepts such as the dimensionality of the realization space, the uniqueness of solutions, and the compatibility of measurements, have been overlooked. In this paper, we provide a dimensional analysis of the realization space for the two-sector Fock space model for conjunction of concepts focusing on the first and second sectors separately. We then introduce various representation of concepts that arise from the use of unitary operators in the realization space. In these concrete representations, a pair of concepts and their combination are modeled by a single conceptual state, and by a collection of exemplar-dependent operators. Therefore, they are consistent with cognitive modeling principles. This framework not only provides a uniform approach to model an entire data set, but, because all measurement operators are expressed in the same basis, allows us to address the question of compatibility of measurements. In particular, we present evidence that it may be possible to predict non-commutative effects from partial measurements of conceptual combinations.

  15. Community-Based Participatory Research Conceptual Model: Community Partner Consultation and Face Validity

    PubMed Central

    Belone, Lorenda; Lucero, JE.; Duran, B.; Tafoya, G.; Baker, EA.; Chan, D.; Chang, C.; Greene-Moton, E.; Kelley, M.; Wallerstein, Nina

    2016-01-01

    A national community based participatory research (CBPR) team developed a conceptual/logic model of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the model primarily developed through academic literature and expert consensus-building, we sought community input to assess face validity and acceptability. Our research team conducted semi-structured focus groups with six partnerships nation-wide. Participants validated and expanded upon existing model constructs and identified new constructs based on “real-world” praxis, resulting in a revised model. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the model, we found community face validity and capacity to adapt the model to diverse contexts. We recommend partnerships use and adapt the CBPR model and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals. PMID:25361792

  16. Community-Based Participatory Research Conceptual Model: Community Partner Consultation and Face Validity.

    PubMed

    Belone, Lorenda; Lucero, Julie E; Duran, Bonnie; Tafoya, Greg; Baker, Elizabeth A; Chan, Domin; Chang, Charlotte; Greene-Moton, Ella; Kelley, Michele A; Wallerstein, Nina

    2016-01-01

    A national community-based participatory research (CBPR) team developed a conceptual model of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the model primarily developed through academic literature and expert consensus building, we sought community input to assess face validity and acceptability. Our research team conducted semi-structured focus groups with six partnerships nationwide. Participants validated and expanded on existing model constructs and identified new constructs based on "real-world" praxis, resulting in a revised model. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the model, we found community face validity and capacity to adapt the model to diverse contexts. We recommend partnerships use and adapt the CBPR model and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals.

  17. Accelerating advances in continental domain hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew; Wagener, Thorsten; Farmer, William H.; Andréassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas

    2015-12-01

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  18. Accelerating advances in continental domain hydrologic modeling

    USGS Publications Warehouse

    Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew R.; Wagener, Thorsten; Farmer, William H.; Andreassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas M.

    2015-01-01

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  19. Comparison of a Neural Network and a Conceptual Model for Rainfall-Runoff Modelling with Monthly Input

    NASA Astrophysics Data System (ADS)

    Chochlidakis, Chronis; Daliakopoulos, Ioannis; Tsanis, Ioannis

    2014-05-01

    Rainfall-runoff (RR) models contain parameters that can seldom be directly measured or estimated by expert judgment, but are rather inferred by calibration against a historical record of input-output datasets. Here, a comparison is made between a conceptual model and an Artificial Neural Network (ANN) for efficient modeling of complex hydrological processes. The monthly rainfall, streamflow, and evapotranspiration data from 15 catchments in Crete, Greece are used to compare the proposed methodologies. Genetic Algorithms (GA) are applied for the stochastic calibration of the parameters in the Sacramento Soil Moisture Accounting (SAC-SMA) model yielding R2 values between 0.65 and 0.90. A Feedforward NN (FNN) is trained using a time delay approach, optimized through trial and error for each catchment, yielding R2 values between 0.70 and 0.91. The results obtained show that the ANN models can be superior to the conventional conceptual models due to their ability to handle the non-linearity and dynamic nature of the natural physical processes in a more efficient manner. On the other hand, SAC-SMA depicts high flows with greater accuracy and results suggest that conceptual models can be more robust in extrapolating beyond historical record limits.

  20. Bayesian model selection in hydrogeophysics: Application to conceptual subsurface models of the South Oyster Bacterial Transport Site, Virginia, USA

    NASA Astrophysics Data System (ADS)

    Brunetti, Carlotta; Linde, Niklas; Vrugt, Jasper A.

    2017-04-01

    Geophysical data can help to discriminate among multiple competing subsurface hypotheses (conceptual models). Here, we explore the merits of Bayesian model selection in hydrogeophysics using crosshole ground-penetrating radar data from the South Oyster Bacterial Transport Site in Virginia, USA. Implementation of Bayesian model selection requires computation of the marginal likelihood of the measured data, or evidence, for each conceptual model being used. In this paper, we compare three different evidence estimators, including (1) the brute force Monte Carlo method, (2) the Laplace-Metropolis method, and (3) the numerical integration method proposed by Volpi et al. (2016). The three types of subsurface models that we consider differ in their treatment of the porosity distribution and use (a) horizontal layering with fixed layer thicknesses, (b) vertical layering with fixed layer thicknesses and (c) a multi-Gaussian field. Our results demonstrate that all three estimators provide equivalent results in low parameter dimensions, yet in higher dimensions the brute force Monte Carlo method is inefficient. The isotropic multi-Gaussian model is most supported by the travel time data with Bayes factors that are larger than 10100 compared to conceptual models that assume horizontal or vertical layering of the porosity field.

  1. Enhancing student teachers' epistemological beliefs about models and conceptual understanding through a model-based inquiry process

    NASA Astrophysics Data System (ADS)

    Soulios, Ioannis; Psillos, Dimitris

    2016-05-01

    In this study we present the structure and implementation of a model-based inquiry teaching-learning sequence (TLS) integrating expressive, experimental and exploratory modelling pedagogies in a cyclic manner, with the aim of enhancing primary education student teachers' epistemological beliefs about the aspects, nature, purpose and change of models as well as their conceptual understanding of light phenomena related to properties of optical fibres. The subjects were 16 prospective primary teachers involved in modelling activities, employing both hands-on experiments and computer modelling activities, based on the application of the ray model. Student teachers were tested before and after the implementation of the TLS by semi-structured interviews and a written questionnaire. Results show that before the TLS most students adopted epistemologically naïve realistic beliefs about models, whereas after the TLS there was an overall significant transition from naïve to more sophisticated epistemological beliefs, as well as significant improvements in their conceptual knowledge about light phenomena. Nevertheless, the relation between epistemological beliefs and conceptual understanding seems to be aspect-dependent, so our evidence suggests that more educational effort is required in order to establish a coherent relationship between them.

  2. A new conceptual paradigm for the haemodynamics of salt-sensitive hypertension: a mathematical modelling approach

    PubMed Central

    Averina, Viktoria A; Othmer, Hans G; Fink, Gregory D; Osborn, John W

    2012-01-01

    A conceptually novel mathematical model of neurogenic angiotensin II-salt hypertension is developed and analysed. The model consists of a lumped parameter circulatory model with two parallel vascular beds; two distinct control mechanisms for both natriuresis and arterial resistances can be implemented, resulting in four versions of the model. In contrast with the classical Guyton–Coleman model (GC model) of hypertension, in the standard version of our new model natriuresis is assumed to be independent of arterial pressure and instead driven solely by sodium intake; arterial resistances are driven by increased sympathetic nervous system activity in response to the elevated plasma angiotensin II and increased salt intake (AngII-salt). We compare the standard version of our new model against a simplified Guyton–Coleman model in which natriuresis is a function of arterial pressure via the pressure–natriuresis mechanism, and arterial resistances are controlled via the whole-body autoregulation mechanism. We show that the simplified GC model and the new model correctly predict haemodynamic and renal excretory responses to induced changes in angiotensin II and sodium inputs. Importantly, the new model reproduces the pressure–natriuresis relationship – the correlation between arterial pressure and sodium excretion – despite the assumption of pressure-independent natriuresis. These results show that our model provides a conceptually new alternative to Guyton's theory without contradicting observed haemodynamic changes or pressure–natriuresis relationships. Furthermore, the new model supports the view that hypertension need not necessarily have a renal aetiology and that long-term arterial pressure could be determined by sympathetic nervous system activity without involving the renal sympathetic nerves. PMID:22890716

  3. Advancements in predictive plasma formation modeling

    NASA Astrophysics Data System (ADS)

    Purvis, Michael A.; Schafgans, Alexander; Brown, Daniel J. W.; Fomenkov, Igor; Rafac, Rob; Brown, Josh; Tao, Yezheng; Rokitski, Slava; Abraham, Mathew; Vargas, Mike; Rich, Spencer; Taylor, Ted; Brandt, David; Pirati, Alberto; Fisher, Aaron; Scott, Howard; Koniges, Alice; Eder, David; Wilks, Scott; Link, Anthony; Langer, Steven

    2016-03-01

    We present highlights from plasma simulations performed in collaboration with Lawrence Livermore National Labs. This modeling is performed to advance the rate of learning about optimal EUV generation for laser produced plasmas and to provide insights where experimental results are not currently available. The goal is to identify key physical processes necessary for an accurate and predictive model capable of simulating a wide range of conditions. This modeling will help to drive source performance scaling in support of the EUV Lithography roadmap. The model simulates pre-pulse laser interaction with the tin droplet and follows the droplet expansion into the main pulse target zone. Next, the interaction of the expanded droplet with the main laser pulse is simulated. We demonstrate the predictive nature of the code and provide comparison with experimental results.

  4. Horizontal Violence and the Quality and Safety of Patient Care: A Conceptual Model

    PubMed Central

    Purpora, Christina; Blegen, Mary A.

    2012-01-01

    For many years, nurses in international clinical and academic settings have voiced concern about horizontal violence among nurses and its consequences. However, no known framework exists to guide research on the topic to explain these consequences. This paper presents a conceptual model that was developed from four theories to illustrate how the quality and safety of patient care could be affected by horizontal violence. Research is needed to validate the new model and to gather empirical evidence of the consequences of horizontal violence on which to base recommendations for future research, education, and practice. PMID:22655187

  5. Faculty empowerment of students to foster civility in nursing education: a merging of two conceptual models.

    PubMed

    Clark, Cynthia M; Davis Kenaley, Bonnie L

    2011-01-01

    Academic incivility negatively impacts faculty and student well-being, weakens professional relationships, and impedes effective teaching and learning. This article addresses the prevalent concern of student incivility and provides useful strategies for faculty to empower students. Two conceptual models, Fostering Civility in Nursing Education and an Empowerment Model, were merged to illustrate how the concepts of civility and empowerment can be combined to foster civility in nursing education. Empowerment domains of motivation, psychic comfort, problem-solving, and self-direction are explored as influential factors promoting constructive reciprocal engagement and civility and, ultimately, enhancing professionalism in a complex and ever-changing health system.

  6. Using case studies based on a nursing conceptual model to teach medical-surgical nursing.

    PubMed

    DeSanto-Madeya, Susan

    2007-10-01

    Nurse educators are continually challenged to develop teaching strategies that enhance students' critical thinking, problem-solving, and decision-making skills. Case studies are a creative learning strategy that fosters these skills through the use of in-depth descriptions of realistic clinical situations. Conceptual models of nursing provide a unique body of knowledge that can be used to guide construction of case studies and enhance application of didactic course content to nursing practice. In this column, the author discusses the use of case studies constructed within the context of the Roy adaptation model for a senior level medical-surgical nursing course.

  7. Rubber airplane: Constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Viewgraphs on Rubber Airplane: Constraint-based Component-Modeling for Knowledge Representation in Computer Aided Conceptual Design are presented. Topics covered include: computer aided design; object oriented programming; airfoil design; surveillance aircraft; commercial aircraft; aircraft design; and launch vehicles.

  8. Developing and validating a conceptual model of recurring problems in teaching clinic.

    PubMed

    Smith, C Scott; Morris, Magdalena; Hill, William; Francovich, Chris; Christiano, Jennifer

    2006-08-01

    Recurrent problems in medical teaching clinic are common and difficult to address because of complex interpersonal dynamics. To minimize this difficulty, we developed a conceptual model that simplifies problems and identifies the root cause of tension between groups in clinic. We used recursive analysis and modeling of the data from a larger multi-site, multi-method study of problems in teaching clinic. The first dataset from this study consisted of problem lists generated and prioritized by knowledgeable insiders from each site. The second dataset was a cultural consensus analysis independently performed at each site. The final model was checked for face validity and construct validity (using model predictions versus prior data and convergent/discriminant analysis). The study was performed in five Veterans Affairs teaching clinics in the U.S. Our final model, the Perception of Care Map, is a pentagram with five critical perspectives of the clinic visit. These five perspectives are structured care, educational care, relationship-based care, algorithmic care and efficient care. Each group emphasizes one or more of these perspectives, and group locations on the conceptual map explain the observed tensions between groups. Validity of the model is high. The Perception of Care Map may be a useful adjunct for understanding and addressing recurrent problems in teaching clinic.

  9. Advanced Small Modular Reactor Economics Model Development

    SciTech Connect

    Harrison, Thomas J.

    2014-10-01

    The US Department of Energy Office of Nuclear Energy’s Advanced Small Modular Reactor (SMR) research and development activities focus on four key areas: Developing assessment methods for evaluating advanced SMR technologies and characteristics; and Developing and testing of materials, fuels and fabrication techniques; and Resolving key regulatory issues identified by US Nuclear Regulatory Commission and industry; and Developing advanced instrumentation and controls and human-machine interfaces. This report focuses on development of assessment methods to evaluate advanced SMR technologies and characteristics. Specifically, this report describes the expansion and application of the economic modeling effort at Oak Ridge National Laboratory. Analysis of the current modeling methods shows that one of the primary concerns for the modeling effort is the handling of uncertainty in cost estimates. Monte Carlo–based methods are commonly used to handle uncertainty, especially when implemented by a stand-alone script within a program such as Python or MATLAB. However, a script-based model requires each potential user to have access to a compiler and an executable capable of handling the script. Making the model accessible to multiple independent analysts is best accomplished by implementing the model in a common computing tool such as Microsoft Excel. Excel is readily available and accessible to most system analysts, but it is not designed for straightforward implementation of a Monte Carlo–based method. Using a Monte Carlo algorithm requires in-spreadsheet scripting and statistical analyses or the use of add-ons such as Crystal Ball. An alternative method uses propagation of error calculations in the existing Excel-based system to estimate system cost uncertainty. This method has the advantage of using Microsoft Excel as is, but it requires the use of simplifying assumptions. These assumptions do not necessarily bring into question the analytical results. In fact, the

  10. . Ecological conceptual models: a framework and case study on ecosystem management for South Florida sustainability

    USGS Publications Warehouse

    Gentile, J.H.; Harwell, M.A.; Cropper, W.; Harwell, C. C.; DeAngelis, Donald L.; Davis, S.; Ogden, J.C.; Lirman, D.

    2001-01-01

    The Everglades and South Florida ecosystems are the focus of national and international attention because of their current degraded and threatened state. Ecological risk assessment, sustainability and ecosystem and adaptive management principles and processes are being used nationally as a decision and policy framework for a variety of types of ecological assessments. The intent of this study is to demonstrate the application of these paradigms and principles at a regional scale. The effects-directed assessment approach used in this study consists of a retrospective, eco-epidemiological phase to determine the causes for the current conditions and a prospective predictive risk-based assessment using scenario analysis to evaluate future options. Embedded in these assessment phases is a process that begins with the identification of goals and societal preferences which are used to develop an integrated suite of risk-based and policy relevant conceptual models. Conceptual models are used to illustrate the linkages among management (societal) actions, environmental stressors, and societal/ecological effects, and provide the basis for developing and testing causal hypotheses. These models, developed for a variety of landscape units and their drivers, stressors, and endpoints, are used to formulate hypotheses to explain the current conditions. They are also used as the basis for structuring management scenarios and analyses to project the temporal and spatial magnitude of risk reduction and system recovery. Within the context of recovery, the conceptual models are used in the initial development of performance criteria for those stressors that are determined to be most important in shaping the landscape, and to guide the use of numerical models used to develop quantitative performance criteria in the scenario analysis. The results will be discussed within an ecosystem and adaptive management framework that provides the foundation for decision making.

  11. A conceptual model of primary productivity in shallow streams using biomass simulation. Technical completion report

    SciTech Connect

    Elliott, J.C.; McDonnell, A.J.

    1982-06-01

    A conceptual model for primary productivity was developed for application to rooted aquatic macrophytes in streams to assist studies of eutrophication and control of water quality in supplementing outputs of dissolved oxygen (DO) models of pollution loads. This model included a first-order differential equation of biomass, with specific rates for photosynthesis, respiration, and death. A model component was developed to describe available light spatially/temporally in the weed bed, as reduced from extraterrestrial solar radiation. A DO model component included terms for photosynthetic production, plant respiration, and a benthal sink due to dead plant matter decay. The latter, a first-order exponential oxygen sink, had not been previously included in DO models.

  12. Evaluation of the US DOE's conceptual model of hydrothermal activity at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Dublyansky, Y. V.

    2012-11-01

    A unique conceptual model envisaging conductive heating of rocks in the thick unsaturated zone of Yucca Mountain, Nevada by a silicic pluton emplaced several kilometers away is accepted by the US Department of Energy (DOE) as an explanation of the elevated depositional temperatures measured in fluid inclusions in secondary fluorite and calcite. Acceptance of this model allowed the DOE not to consider hydrothermal activity in the performance assessment of the proposed high-level nuclear waste disposal facility. Evaluation shows that validation of the model by computational modeling and by observations at a natural analog site was unsuccessful. Due to the lack of validation, the reliance on this model must be discontinued and the scientific defensibility of decisions which rely on this model must be re-evaluated.

  13. Evolution of the conceptual model of unsaturated zone hydrology at yucca mountain, nevada

    SciTech Connect

    Flint, A. L.; Flint, L. E.; Bodvarsson, G. S.; Kwicklis, E. M.; Fabryka-Martin, J.

    2001-02-01

    Yucca Mountain is an arid site proposed for consideration as the United States' first underground high-level radioactive waste repository. Low rainfall (approximately 170 mm/yr) and a thick unsaturated zone (500-1000 m) are important physical attributes of the site because the quantity of water likely to reach the waste and the paths and rates of movement of the water to the saturated zone under future climates would be major factors in controlling the concentrations and times of arrival of radionuclides at the surrounding accessible environment. The framework for understanding the hydrologic processes that occur at this site and that control how quickly water will penetrate through the unsaturated zone to the water table has evolved during the past 15 yr. Early conceptual models assumed that very small volumes of water infiltrated into the bedrock (0.5-4.5 mm/yr, or 2-3 percent of rainfall), that much of the infiltrated water flowed laterally within the upper nonwelded units because o f capillary barrier effects, and that the remaining water flowed down faults with a small amount flowing through the matrix of the lower welded, fractured rocks. It was believed that the matrix had to be saturated for fractures to show. However, accumulating evidence indicated that infiltration rates were higher than initially estimated, such as infiltration modeling based on neutron borehole data, bomb-pulse isotopes deep in the mountain, perched water analyses and thermal analyses. Mechanisms supporting lateral diversion did not apply at these higher fluxes, and the flux calculated in the lower welded unit exceeded the conductivity of the matrix, implying vertical flow of water into the high permeability fractures of the potential repository host rock, and disequilibrium between matrix and fracture water potentials. The development of numerical modeling methods and parameter values evolved concurrently with the conceptual model in order to account for the observed field data

  14. Evolution of the conceptual model of unsaturated zone hydrology at Yucca Mountain, Nevada

    USGS Publications Warehouse

    Flint, Alan L.; Flint, Lorraine E.; Bodvarsson, Gudmundur S.; Kwicklis, Edward M.; Fabryka-Martin, June

    2001-01-01

    Yucca Mountain is an arid site proposed for consideration as the United States’ first underground high-level radioactive waste repository. Low rainfall (approximately 170 mm/yr) and a thick unsaturated zone (500–1000 m) are important physical attributes of the site because the quantity of water likely to reach the waste and the paths and rates of movement of the water to the saturated zone under future climates would be major factors in controlling the concentrations and times of arrival of radionuclides at the surrounding accessible environment. The framework for understanding the hydrologic processes that occur at this site and that control how quickly water will penetrate through the unsaturated zone to the water table has evolved during the past 15 yr. Early conceptual models assumed that very small volumes of water infiltrated into the bedrock (0.5–4.5 mm/yr, or 2–3 percent of rainfall), that much of the infiltrated water flowed laterally within the upper nonwelded units because of capillary barrier effects, and that the remaining water flowed down faults with a small amount flowing through the matrix of the lower welded, fractured rocks. It was believed that the matrix had to be saturated for fractures to flow. However, accumulating evidence indicated that infiltration rates were higher than initially estimated, such as infiltration modeling based on neutron borehole data, bomb-pulse isotopes deep in the mountain, perched water analyses and thermal analyses. Mechanisms supporting lateral diversion did not apply at these higher fluxes, and the flux calculated in the lower welded unit exceeded the conductivity of the matrix, implying vertical flow of water in the high permeability fractures of the potential repository host rock, and disequilibrium between matrix and fracture water potentials. The development of numerical modeling methods and parameter values evolved concurrently with the conceptual model in order to account for the observed field data

  15. Empirical evaluation of the conceptual model underpinning a regional aquatic long-term monitoring program using causal modelling

    USGS Publications Warehouse

    Irvine, Kathryn M.; Miller, Scott; Al-Chokhachy, Robert K.; Archer, Erik; Roper, Brett B.; Kershner, Jeffrey L.

    2015-01-01

    Conceptual models are an integral facet of long-term monitoring programs. Proposed linkages between drivers, stressors, and ecological indicators are identified within the conceptual model of most mandated programs. We empirically evaluate a conceptual model developed for a regional aquatic and riparian monitoring program using causal models (i.e., Bayesian path analysis). We assess whether data gathered for regional status and trend estimation can also provide insights on why a stream may deviate from reference conditions. We target the hypothesized causal pathways for how anthropogenic drivers of road density, percent grazing, and percent forest within a catchment affect instream biological condition. We found instream temperature and fine sediments in arid sites and only fine sediments in mesic sites accounted for a significant portion of the maximum possible variation explainable in biological condition among managed sites. However, the biological significance of the direct effects of anthropogenic drivers on instream temperature and fine sediments were minimal or not detected. Consequently, there was weak to no biological support for causal pathways related to anthropogenic drivers’ impact on biological condition. With weak biological and statistical effect sizes, ignoring environmental contextual variables and covariates that explain natural heterogeneity would have resulted in no evidence of human impacts on biological integrity in some instances. For programs targeting the effects of anthropogenic activities, it is imperative to identify both land use practices and mechanisms that have led to degraded conditions (i.e., moving beyond simple status and trend estimation). Our empirical evaluation of the conceptual model underpinning the long-term monitoring program provided an opportunity for learning and, consequently, we discuss survey design elements that require modification to achieve question driven monitoring, a necessary step in the practice of

  16. Conceptual design and analysis of a dynamic scale model of the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Davis, D. A.; Gronet, M. J.; Tan, M. K.; Thorne, J.

    1994-01-01

    This report documents the conceptual design study performed to evaluate design options for a subscale dynamic test model which could be used to investigate the expected on-orbit structural dynamic characteristics of the Space Station Freedom early build configurations. The baseline option was a 'near-replica' model of the SSF SC-7 pre-integrated truss configuration. The approach used to develop conceptual design options involved three sets of studies: evaluation of the full-scale design and analysis databases, conducting scale factor trade studies, and performing design sensitivity studies. The scale factor trade study was conducted to develop a fundamental understanding of the key scaling parameters that drive design, performance and cost of a SSF dynamic scale model. Four scale model options were estimated: 1/4, 1/5, 1/7, and 1/10 scale. Prototype hardware was fabricated to assess producibility issues. Based on the results of the study, a 1/4-scale size is recommended based on the increased model fidelity associated with a larger scale factor. A design sensitivity study was performed to identify critical hardware component properties that drive dynamic performance. A total of 118 component properties were identified which require high-fidelity replication. Lower fidelity dynamic similarity scaling can be used for non-critical components.

  17. Bayesian Assessment of the Uncertainties of Estimates of a Conceptual Rainfall-Runoff Model Parameters

    NASA Astrophysics Data System (ADS)

    Silva, F. E. O. E.; Naghettini, M. D. C.; Fernandes, W.

    2014-12-01

    This paper evaluated the uncertainties associated with the estimation of the parameters of a conceptual rainfall-runoff model, through the use of Bayesian inference techniques by Monte Carlo simulation. The Pará River sub-basin, located in the upper São Francisco river basin, in southeastern Brazil, was selected for developing the studies. In this paper, we used the Rio Grande conceptual hydrologic model (EHR/UFMG, 2001) and the Markov Chain Monte Carlo simulation method named DREAM (VRUGT, 2008a). Two probabilistic models for the residues were analyzed: (i) the classic [Normal likelihood - r ≈ N (0, σ²)]; and (ii) a generalized likelihood (SCHOUPS & VRUGT, 2010), in which it is assumed that the differences between observed and simulated flows are correlated, non-stationary, and distributed as a Skew Exponential Power density. The assumptions made for both models were checked to ensure that the estimation of uncertainties in the parameters was not biased. The results showed that the Bayesian approach proved to be adequate to the proposed objectives, enabling and reinforcing the importance of assessing the uncertainties associated with hydrological modeling.

  18. A conceptual life-history model for pallid and shovelnose sturgeon

    USGS Publications Warehouse

    Wildhaber, Mark L.; DeLonay, Aaron J.; Papoulias, Diana M.; Galat, David L.; Jacobson, Robert B.; Simpkins, Darin G.; Braaten, P. J.; Korschgen, Carl E.; Mac, Michael J.

    2007-01-01

    Intensive management of the Missouri and Mississippi Rivers has resulted in dramatic physical changes to these rivers. These changes have been implicated as causative agents in the decline of pallid sturgeon. The pallid sturgeon, federally listed as endangered, is endemic to the turbid waters of the Missouri River and the Lower Mississippi River. The sympatric shovelnose sturgeon historically was more common and widespread than the pallid sturgeon. Habitat alteration, river regulation, pollution, and over-harvest have resulted in the now predictable patterns of decline and localized extirpation of sturgeon across species and geographic areas. Symptomatic of this generalized pattern of decline is poor reproductive success, and low or no recruitment of wild juveniles to the adult population. The purpose of this report is to introduce a conceptual life-history model of the factors that affect reproduction, growth, and survival of shovelnose and pallid sturgeons. The conceptual model provided here was developed to organize the understanding about the complex life history of Scaphirhynchus sturgeons. It was designed to be used for communication, planning, and to provide the structure for a population-forecasting model. These models are intended to be dynamic and responsive to new information and changes in river management, thereby providing scientists, stakeholders, and managers with ways to improve understanding of the effects of management actions on the ecological requirements of Scaphirhynchus sturgeons. As new scientific knowledge becomes available, it could be included in the model in many ways at various integration levels.

  19. Towards an Ecology of the Lung: New Conceptual Models of Pulmonary Microbiology and Pneumonia Pathogenesis

    PubMed Central

    Dickson, Robert P.; Erb-Downward, John R.; Huffnagle, Gary B.

    2014-01-01

    Summary Pneumonia is a major cause of morbidity and mortality for which no new methods of treatment have entered clinical practice since the discovery of antibiotics. Innovations in the techniques of culture-independent microbial identification have shown that the lungs, previously deemed sterile in the absence of infection, contain diverse and dynamic communities of microbes. In this Personal View, we argue that these observations have shown the inadequacy of traditional conceptual models of lung microbiology and the pathogenesis of pneumonia, hampering progress in research and practice. We propose three new conceptual models to replace the traditional models of lung microbiology: an adapted island model of lung biogeography, the effect of environmental gradients on lung microbiota, and pneumonia as an emergent phenomenon propelled by unexplored positive feedback loops. We argue that the ecosystem of lung microbiota has all of the features of a complex adaptive system: diverse entities interacting with each other within a common space, showing interdependent actions and possessing the capacity to adapt to changes in conditions. Complex adaptive systems are fundamentally different in behaviour from the simple, linear systems typified by the traditional model of pneumonia pathogenesis, and need distinct analytical approaches. PMID:24621685

  20. Chlorine-36 data at Yucca Mountain: Statistical tests of conceptual models for unsaturated-zone flow

    USGS Publications Warehouse

    Campbell, K.; Wolfsberg, A.; Fabryka-Martin, J.; Sweetkind, D.

    2003-01-01

    An extensive set of chlorine-36 (36Cl) data has been collected in the Exploratory Studies Facility (ESF), an 8-km-long tunnel at Yucca Mountain, Nevada, for the purpose of developing and testing conceptual models of flow and transport in the unsaturated zone (UZ) at this site. At several locations, the measured values of 36Cl/Cl ratios for salts leached from rock samples are high enough to provide strong evidence that at least a small component of bomb-pulse 36Cl, fallout from atmospheric testing of nuclear devices in the 1950s and 1960s, was measured, implying that some fraction of the water traveled from the ground surface through 200-300 m of unsaturated rock to the level of the ESF during the last 50 years. These data are analyzed here using a formal statistical approach based on log-linear models to evaluate alternative conceptual models for the distribution of such fast flow paths. The most significant determinant of the presence of bomb-pulse 36Cl in a sample from the welded Topopah Spring unit (TSw) is the structural setting from which the sample was collected. Our analysis generally supports the conceptual model that a fault that cuts through the nonwelded Paintbrush tuff unit (PTn) that overlies the TSw is required in order for bomb-pulse 36Cl to be transmitted to the sample depth in less than 50 years. Away from PTn-cutting faults, the ages of water samples at the ESF appear to be a strong function of the thickness of the nonwelded tuff between the ground surface and the ESF, due to slow matrix flow in that unit. ?? 2002 Elsevier Science B.V. All rights reserved.

  1. Chlorine-36 data at Yucca Mountain: statistical tests of conceptual models for unsaturated-zone flow

    NASA Astrophysics Data System (ADS)

    Campbell, Katherine; Wolfsberg, Andrew; Fabryka-Martin, June; Sweetkind, Donald

    2003-05-01

    An extensive set of chlorine-36 ( 36Cl) data has been collected in the Exploratory Studies Facility (ESF), an 8-km-long tunnel at Yucca Mountain, Nevada, for the purpose of developing and testing conceptual models of flow and transport in the unsaturated zone (UZ) at this site. At several locations, the measured values of 36Cl/Cl ratios for salts leached from rock samples are high enough to provide strong evidence that at least a small component of bomb-pulse 36Cl, fallout from atmospheric testing of nuclear devices in the 1950s and 1960s, was measured, implying that some fraction of the water traveled from the ground surface through 200-300 m of unsaturated rock to the level of the ESF during the last 50 years. These data are analyzed here using a formal statistical approach based on log-linear models to evaluate alternative conceptual models for the distribution of such fast flow paths. The most significant determinant of the presence of bomb-pulse 36Cl in a sample from the welded Topopah Spring unit (TSw) is the structural setting from which the sample was collected. Our analysis generally supports the conceptual model that a fault that cuts through the nonwelded Paintbrush tuff unit (PTn) that overlies the TSw is required in order for bomb-pulse 36Cl to be transmitted to the sample depth in less than 50 years. Away from PTn-cutting faults, the ages of water samples at the ESF appear to be a strong function of the thickness of the nonwelded tuff between the ground surface and the ESF, due to slow matrix flow in that unit.

  2. Chlorine-36 data at Yucca Mountain: statistical tests of conceptual models for unsaturated-zone flow.

    PubMed

    Campbell, Katherine; Wolfsberg, Andrew; Fabryka-Martin, June; Sweetkind, Donald

    2003-01-01

    An extensive set of chlorine-36 (36Cl) data has been collected in the Exploratory Studies Facility (ESF), an 8-km-long tunnel at Yucca Mountain, Nevada, for the purpose of developing and testing conceptual models of flow and transport in the unsaturated zone (UZ) at this site. At several locations, the measured values of 36Cl/Cl ratios for salts leached from rock samples are high enough to provide strong evidence that at least a small component of bomb-pulse 36Cl, fallout from atmospheric testing of nuclear devices in the 1950s and 1960s, was measured, implying that some fraction of the water traveled from the ground surface through 200-300 m of unsaturated rock to the level of the ESF during the last 50 years. These data are analyzed here using a formal statistical approach based on log-linear models to evaluate alternative conceptual models for the distribution of such fast flow paths. The most significant determinant of the presence of bomb-pulse 36Cl in a sample from the welded Topopah Spring unit (TSw) is the structural setting from which the sample was collected. Our analysis generally supports the conceptual model that a fault that cuts through the nonwelded Paintbrush tuff unit (PTn) that overlies the TSw is required in order for bomb-pulse 36Cl to be transmitted to the sample depth in less than 50 years. Away from PTn-cutting faults, the ages of water samples at the ESF appear to be a strong function of the thickness of the nonwelded tuff between the ground surface and the ESF, due to slow matrix flow in that unit.

  3. Reducing structural uncertainty in conceptual hydrological modelling in the semi-arid Andes

    NASA Astrophysics Data System (ADS)

    Hublart, P.; Ruelland, D.; Dezetter, A.; Jourde, H.

    2015-05-01

    The use of lumped, conceptual models in hydrological impact studies requires placing more emphasis on the uncertainty arising from deficiencies and/or ambiguities in the model structure. This study provides an opportunity to combine a multiple-hypothesis framework with a multi-criteria assessment scheme to reduce structural uncertainty in the conceptual modelling of a mesoscale Andean catchment (1515 km2) over a 30-year period (1982-2011). The modelling process was decomposed into six model-building decisions related to the following aspects of the system behaviour: snow accumulation and melt, runoff generation, redistribution and delay of water fluxes, and natural storage effects. Each of these decisions was provided with a set of alternative modelling options, resulting in a total of 72 competing model structures. These structures were calibrated using the concept of Pareto optimality with three criteria pertaining to streamflow simulations and one to the seasonal dynamics of snow processes. The results were analyzed in the four-dimensional (4-D) space of performance measures using a fuzzy c-means clustering technique and a differential split sample test, leading to identify 14 equally acceptable model hypotheses. A filtering approach was then applied to these best-performing structures in order to minimize the overall uncertainty envelope while maximizing the number of enclosed observations. This led to retain eight model hypotheses as a representation of the minimum structural uncertainty that could be obtained with this modelling framework. Future work to better consider model predictive uncertainty should include a proper assessment of parameter equifinality and data errors, as well as the testing of new or refined hypotheses to allow for the use of additional auxiliary observations.

  4. Reducing structural uncertainty in conceptual hydrological modeling in the semi-arid Andes

    NASA Astrophysics Data System (ADS)

    Hublart, P.; Ruelland, D.; Dezetter, A.; Jourde, H.

    2014-10-01

    The use of lumped, conceptual models in hydrological impact studies requires placing more emphasis on the uncertainty arising from deficiencies and/or ambiguities in the model structure. This study provides an opportunity to combine a multiple-hypothesis framework with a multi-criteria assessment scheme to reduce structural uncertainty in the conceptual modeling of a meso-scale Andean catchment (1515 km2) over a 30 year period (1982-2011). The modeling process was decomposed into six model-building decisions related to the following aspects of the system behavior: snow accumulation and melt, runoff generation, redistribution and delay of water fluxes, and natural storage effects. Each of these decisions was provided with a set of alternative modeling options, resulting in a total of 72 competing model structures. These structures were calibrated using the concept of Pareto optimality with three criteria pertaining to streamflow simulations and one to the seasonal dynamics of snow processes. The results were analyzed in the four-dimensional space of performance measures using a fuzzy c-means clustering technique and a differential split sample test, leading to identify 14 equally acceptable model hypotheses. A filtering approach was then applied to these best-performing structures in order to minimize the overall uncertainty envelope while maximizing the number of enclosed observations. This led to retain 8 model hypotheses as a representation of the minimum structural uncertainty that could be obtained with this modeling framework. Future work to better consider model predictive uncertainty should include a proper assessment of parameter equifinality and data errors, as well as the testing of new or refined hypotheses to allow for the use of additional auxiliary observations.

  5. 76 FR 68011 - Medicare Program; Advanced Payment Model

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    .../seamless-and-coordinated-care-models/advance-payment/ . FOR FURTHER INFORMATION CONTACT: Questions... provide high quality, coordinated care and generate cost savings. The Advance Payment Model will test....innovations.cms.gov/areas-of-focus/seamless-and-coordinated-care-models/advance-payment . II. Provisions...

  6. [Construction of conceptual model of data management for nutrient cycling research].

    PubMed

    Shi, Jianping; Sun, Bo; Yang, Linzhang

    2003-11-01

    A large amount of data have been accumulated from the agro-ecosystem nutrient cycling research during recent years. It is necessary to develop a data management system for global decision-making and for preserving from loss. This paper outlined a conceptual model design based on Entity-Relation (E-R) model, presented the model constructing process from user query, and demonstrated a database system using a given model. The results showed that the database implemented from the designed model could provide the function of querying in terms of time, location and theme, and management of various types of data, such as field observation, theme map and research report, and fast extracting and analysis data with spatio-temporal characteristic.

  7. Rapid implementation of advanced constitutive models

    NASA Astrophysics Data System (ADS)

    Starman, Bojan; Halilovič, Miroslav; Vrh, Marko; Štok, Boris

    2013-12-01

    This paper presents a methodology based on the NICE integration scheme [1, 2] for simple and rapid numerical implementation of a class of plasticity constitutive models. In this regard, an algorithm is purposely developed for the implementation of newly developed advanced constitutive models into explicit finite element framework. The methodology follows the organization of the problem state variables into an extended form, which allows the constitutive models' equations to be organized in such a way, that the algorithm can be optionally extended with minimal effort to integrate also evolution equations related to a description of other specific phenomena, such as damage, distortional hardening, phase transitions, degradation etc. To confirm simplicity of the program implementation, computational robustness, effectiveness and improved accuracy of the implemented integration algorithm, a deep drawing simulation of the cylindrical cup is considered as the case study, performed in ABAQUS/Explicit. As a fairly complex considered model, the YLD2004-18p model [3, 4] is first implemented via external subroutine VUMAT. Further, to give additional proof of the simplicity of the proposed methodology, a combination of the YLD2004-18p model and Gurson-Tvergaard-Needleman model (GTN) is considered. As demonstrated, the implementation is really obtained in a very simple way.

  8. Integrated Methods for Site Characterization and Conceptual Model Development for a Contaminated Fractured-Bedrock Aquifer

    NASA Astrophysics Data System (ADS)

    Johnson, C. D.; Kastrinos, J. R.; Haeni, F. P.

    2005-12-01

    A multi-disciplined and team-based approach was used to integrate geophysical, hydrologic, and chemical data to characterize lithology, fractures, and hydraulic properties of fractured crystalline bedrock and to determine the nature and extent of ground-water contamination from a landfill and former chemical-waste disposal pits at the University of Connecticut. Detection of volatile organic compounds (VOCs) in domestic bedrock wells in the mid-1980s led to this investigation, in which a team comprised of hydrologists, engineers, geophysicists, geologists, chemists, toxicologists, and community-involvement personnel collected, analyzed, and evaluated data; developed and refined a conceptual model of the ground-water flow and contaminant distribution at the site; and evaluated alternatives and implemented a final remediation plan. The characterization phase began in 1999 and the remediation phase is currently ongoing. An integrated and iterative approach of using multiple methods in phases was important for corroborating the interpretation of individual methods and essential for guiding the design and implementation of additional testing at the site. The use of geophysical data early in the investigation allowed the study team to obtain detailed subsurface information using a minimum of boreholes. Surface geophysical methods were used to target potential discharge of contaminants from the landfill for further investigation. Borehole geophysical methods were used to investigate the anomalies identified by surface geophysical methods, the location and orientation of fractures that intersect and surround each well, the direction and magnitude of ambient flow in the wells, and the transmissive fractures that could provide pathways for contaminant migration. Borehole geophysical and hydraulic data were used to design discrete-zone monitoring systems for the collection of hydraulic head and chemical data and to prevent cross contamination through the boreholes. The results

  9. Conceptual model for transport processes in the Culebra Dolomite Member, Rustler Formation

    SciTech Connect

    Holt, R.M.

    1997-08-01

    The Culebra Dolomite Member of the Rustler Formation represents a possible pathway for contaminants from the Waste Isolation Pilot Plant underground repository to the accessible environment. The geologic character of the Culebra is consistent with a double-porosity, multiple-rate model for transport in which the medium is conceptualized as consisting of advective porosity, where solutes are carried by the groundwater flow, and fracture-bounded zones of diffusive porosity, where solutes move through slow advection or diffusion. As the advective travel length or travel time increases, the nature of transport within a double-porosity medium changes. This behavior is important for chemical sorption, because the specific surface area per unit mass of the diffusive porosity is much greater than in the advective porosity. Culebra transport experiments conducted at two different length scales show behavior consistent with a multiple-rate, double-porosity conceptual model for Culebra transport. Tracer tests conducted on intact core samples from the Culebra show no evidence of significant diffusion, suggesting that at the core scale the Culebra can be modeled as a single-porosity medium where only the advective porosity participates in transport. Field tracer tests conducted in the Culebra show strong double-porosity behavior that is best explained using a multiple-rate model.

  10. Description and evaluation of a mechanistically based conceptual model for spall

    SciTech Connect

    Hansen, F.D.; Knowles, M.K.; Thompson, T.W.

    1997-08-01

    A mechanistically based model for a possible spall event at the WIPP site is developed and evaluated in this report. Release of waste material to the surface during an inadvertent borehole intrusion is possible if future states of the repository include high gas pressure and waste material consisting of fine particulates having low mechanical strength. The conceptual model incorporates the physics of wellbore hydraulics coupled to transient gas flow to the intrusion borehole, and mechanical response of the waste. Degraded waste properties using of the model. The evaluations include both numerical and analytical implementations of the conceptual model. A tensile failure criterion is assumed appropriate for calculation of volumes of waste experiencing fragmentation. Calculations show that for repository gas pressures less than 12 MPa, no tensile failure occurs. Minimal volumes of material experience failure below gas pressure of 14 MPa. Repository conditions dictate that the probability of gas pressures exceeding 14 MPa is approximately 1%. For these conditions, a maximum failed volume of 0.25 m{sup 3} is calculated.

  11. Fuzzy cognitive mapping in support of integrated ecosystem assessments: Developing a shared conceptual model among stakeholders.

    PubMed

    Vasslides, James M; Jensen, Olaf P

    2016-01-15

    Ecosystem-based approaches, including integrated ecosystem assessments, are a popular methodology being used to holistically address management issues in social-ecological systems worldwide. In this study we utilized fuzzy logic cognitive mapping to develop conceptual models of a complex estuarine system among four stakeholder groups. The average number of categories in an individual map was not significantly different among groups, and there were no significant differences between the groups in the average complexity or density indices of the individual maps. When ordered by their complexity scores, eight categories contributed to the top four rankings of the stakeholder groups, with six of the categories shared by at least half of the groups. While non-metric multidimensional scaling (nMDS) analysis displayed a high degree of overlap between the individual models across groups, there was also diversity within each stakeholder group. These findings suggest that while all of the stakeholders interviewed perceive the subject ecosystem as a complex series of social and ecological interconnections, there are a core set of components that are present in most of the groups' models that are crucial in managing the system towards some desired outcome. However, the variability in the connections between these core components and the rest of the categories influences the exact nature of these outcomes. Understanding the reasons behind these differences will be critical to developing a shared conceptual model that will be acceptable to all stakeholder groups and can serve as the basis for an integrated ecosystem assessment.

  12. Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta

    USGS Publications Warehouse

    Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

    2012-01-01

    Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and marsh habitats. The model demonstrates feedback loops that affect the Delta ecosystem. Submerged and emergent marsh vegetation act as ecosystem engineers that can create a positive feedback loop by decreasing suspended sediment, increasing water column light, which in turn enables more vegetation. Sea-level rise in open water is partially countered by a negative feedback loop that increases deposition if there is a net decrease in hydrodynamic energy. Manipulation of regional sediment transport is probably the most feasible method to control suspended sediment and thus turbidity. The conceptual model is used to identify information gaps that need to be filled to develop an accurate sediment transport model.

  13. Conceptual framework for model-based analysis of residence time distribution in twin-screw granulation.

    PubMed

    Kumar, Ashish; Vercruysse, Jurgen; Vanhoorne, Valérie; Toiviainen, Maunu; Panouillot, Pierre-Emmanuel; Juuti, Mikko; Vervaet, Chris; Remon, Jean Paul; Gernaey, Krist V; De Beer, Thomas; Nopens, Ingmar

    2015-04-25

    Twin-screw granulation is a promising continuous alternative for traditional batchwise wet granulation processes. The twin-screw granulator (TSG) screws consist of transport and kneading element modules. Therefore, the granulation to a large extent is governed by the residence time distribution within each module where different granulation rate processes dominate over others. Currently, experimental data is used to determine the residence time distributions. In this study, a conceptual model based on classical chemical engineering methods is proposed to better understand and simulate the residence time distribution in a TSG. The experimental data were compared with the proposed most suitable conceptual model to estimate the parameters of the model and to analyse and predict the effects of changes in number of kneading discs and their stagger angle, screw speed and powder feed rate on residence time. The study established that the kneading block in the screw configuration acts as a plug-flow zone inside the granulator. Furthermore, it was found that a balance between the throughput force and conveying rate is required to obtain a good axial mixing inside the twin-screw granulator. Although the granulation behaviour is different for other excipients, the experimental data collection and modelling methods applied in this study are generic and can be adapted to other excipients.

  14. Constraining performance assessment models with tracer test results: a comparison between two conceptual models

    NASA Astrophysics Data System (ADS)

    McKenna, Sean A.; Selroos, Jan-Olof

    Tracer tests are conducted to ascertain solute transport parameters of a single rock feature over a 5-m transport pathway. Two different conceptualizations of double-porosity solute transport provide estimates of the tracer breakthrough curves. One of the conceptualizations (single-rate) employs a single effective diffusion coefficient in a matrix with infinite penetration depth. However, the tracer retention between different flow paths can vary as the ratio of flow-wetted surface to flow rate differs between the path lines. The other conceptualization (multirate) employs a continuous distribution of multiple diffusion rate coefficients in a matrix with variable, yet finite, capacity. Application of these two models with the parameters estimated on the tracer test breakthrough curves produces transport results that differ by orders of magnitude in peak concentration and time to peak concentration at the performance assessment (PA) time and length scales (100,000 years and 1,000 m). These differences are examined by calculating the time limits for the diffusive capacity to act as an infinite medium. These limits are compared across both conceptual models and also against characteristic times for diffusion at both the tracer test and PA scales. Additionally, the differences between the models are examined by re-estimating parameters for the multirate model from the traditional double-porosity model results at the PA scale. Results indicate that for each model the amount of the diffusive capacity that acts as an infinite medium over the specified time scale explains the differences between the model results and that tracer tests alone cannot provide reliable estimates of transport parameters for the PA scale. Results of Monte Carlo runs of the transport models with varying travel times and path lengths show consistent results between models and suggest that the variation in flow-wetted surface to flow rate along path lines is insignificant relative to variability in

  15. Conceptualizing Programme Evaluation

    ERIC Educational Resources Information Center

    Hassan, Salochana

    2013-01-01

    The main thrust of this paper deals with the conceptualization of theory-driven evaluation pertaining to a tutor training programme. Conceptualization of evaluation, in this case, is an integration between a conceptualization model as well as a theoretical framework in the form of activity theory. Existing examples of frameworks of programme…

  16. Conceptual design of a self-deployable, high performance parabolic concentrator for advanced solar-dynamic power systems

    NASA Technical Reports Server (NTRS)

    Dehne, Hans Joachim; Duffy, Donald R.

    1989-01-01

    A summary is presented of the concentrator conceptual design work performed under a NASA-funded project. The design study centers around two basic efforts: conceptual design of a self-deploying, high-performance parabolic concentrator; and materials selection for a lightweight, shape-stable concentrator. The primary structural material selected for the concentrator is PEEK/carbon fiber composite. The deployment concept utilizes rigid gore-shaped reflective panels. The assembled concentrator takes a circular shape with a void in the center. The deployable solar concentrator concept is applicable to a range of solar dynamic power systems of 25 kWe to more than 75 kWe.

  17. Optimal observation network design for conceptual model discrimination and uncertainty reduction

    NASA Astrophysics Data System (ADS)

    Pham, Hai V.; Tsai, Frank T.-C.

    2016-02-01

    This study expands the Box-Hill discrimination function to design an optimal observation network to discriminate conceptual models and, in turn, identify a most favored model. The Box-Hill discrimination function measures the expected decrease in Shannon entropy (for model identification) before and after the optimal design for one additional observation. This study modifies the discrimination function to account for multiple future observations that are assumed spatiotemporally independent and Gaussian-distributed. Bayesian model averaging (BMA) is used to incorporate existing observation data and quantify future observation uncertainty arising from conceptual and parametric uncertainties in the discrimination function. In addition, the BMA method is adopted to predict future observation data in a statistical sense. The design goal is to find optimal locations and least data via maximizing the Box-Hill discrimination function value subject to a posterior model probability threshold. The optimal observation network design is illustrated using a groundwater study in Baton Rouge, Louisiana, to collect additional groundwater heads from USGS wells. The sources of uncertainty creating multiple groundwater models are geological architecture, boundary condition, and fault permeability architecture. Impacts of considering homoscedastic and heteroscedastic future observation data and the sources of uncertainties on potential observation areas are analyzed. Results show that heteroscedasticity should be considered in the design procedure to account for various sources of future observation uncertainty. After the optimal design is obtained and the corresponding data are collected for model updating, total variances of head predictions can be significantly reduced by identifying a model with a superior posterior model probability.

  18. A conceptual model to estimate cost effectiveness of the indoor environment improvements

    SciTech Connect

    Seppanen, Olli; Fisk, William J.

    2003-06-01

    Macroeconomic analyses indicate a high cost to society of a deteriorated indoor climate. The few example calculations performed to date indicate that measures taken to improve IEQ are highly cost-effective when health and productivity benefits are considered. We believe that cost-benefit analyses of building designs and operations should routinely incorporate health and productivity impacts. As an initial step, we developed a conceptual model that shows the links between improvements in IEQ and the financial gains from reductions in medical care and sick leave, improved work performance, lower employee turn over, and reduced maintenance due to fewer complaints.

  19. Conceptual resources for constructing the concepts of electricity: the role of models, analogies and imagination

    NASA Astrophysics Data System (ADS)

    Taber, Keith S.; de Trafford, Tom; Quail, Teresa

    2006-03-01

    The topic of electricity offers considerable challenge for the teacher hoping to provide students with an insight into scientific ways of thinking about circuits. The concepts used to make sense of electric circuits are abstract and students are expected to develop conceptual models of the relationship between non-observable qualities (current, p.d., resistance) in terms of other non-observables such as energy and electrons. Teachers introducing electrical ideas to lower secondary students need to find ways of enticing learners to engage with the topic at a theoretical as well as a phenomenological level. This article explores approaches taken by two trainee teachers working with lower secondary classes in England.

  20. Conceptual model for collision detection and avoidance for runway incursion prevention

    NASA Astrophysics Data System (ADS)

    Latimer, Bridgette A.

    The Federal Aviation Administration (FAA), National Transportation and Safety Board (NTSB), National Aeronautics and Space Administration (NASA), numerous corporate entities, and research facilities have each come together to determine ways to make air travel safer and more efficient. These efforts have resulted in the development of a concept known as the Next Generation (Next Gen) of Aircraft or Next Gen. The Next Gen concept promises to be a clear departure from the way in which aircraft operations are performed today. The Next Gen initiatives require that modifications are made to the existing National Airspace System (NAS) concept of operations, system level requirements, software (SW) and hardware (HW) requirements, SW and HW designs and implementations. A second example of the changes in the NAS is the shift away from air traffic controllers having the responsibility for separation assurance. In the proposed new scheme of free flight, each aircraft would be responsible for assuring that it is safely separated from surrounding aircraft. Free flight would allow the separation minima for enroute aircraft to be reduced from 2000 nautical miles (nm) to 1000 nm. Simply put "Free Flight is a concept of air traffic management that permits pilots and controllers to share information and work together to manage air traffic from pre-flight through arrival without compromising safety [107]." The primary goal of this research project was to create a conceptual model that embodies the essential ingredients needed for a collision detection and avoidance system. This system was required to operate in two modes: air traffic controller's perspective and pilot's perspective. The secondary goal was to demonstrate that the technologies, procedures, and decision logic embedded in the conceptual model were able to effectively detect and avoid collision risks from both perspectives. Embodied in the conceptual model are five distinct software modules: Data Acquisition, State

  1. AFDM: An Advanced Fluid-Dynamics Model

    SciTech Connect

    Wilhelm, D.

    1990-09-01

    This volume describes the Advanced Fluid-Dynamics Model (AFDM) for topologies, flow regimes, and interfacial areas. The objective of these models is to provide values for the interfacial areas between all components existing in a computational cell. The interfacial areas are then used to evaluate the mass, energy, and momentum transfer between the components. A new approach has been undertaken in the development of a model to convect the interfacial areas of the discontinuous velocity fields in the three-velocity-field environment of AFDM. These interfacial areas are called convectible surface areas. The continuous and discontinuous components are chosen using volume fraction and levitation criteria. This establishes so-called topologies for which the convectible surface areas can be determined. These areas are functions of space and time. Solid particulates that are limited to being discontinuous within the bulk fluid are assumed to have a constant size. The convectible surface areas are subdivided to model contacts between two discontinuous components or discontinuous components and the structure. The models have been written for the flow inside of large pools. Therefore, the structure is tracked only as a boundary to the fluid volume without having a direct influence on velocity or volume fraction distribution by means of flow regimes or boundary layer models. 17 refs., 7 tabs., 18 figs.

  2. The role of affective experience in work motivation: Test of a conceptual model

    PubMed Central

    SEO, MYEONG-GU; BARTUNEK, JEAN M.; BARRETT, LISA FELDMAN

    2011-01-01

    Summary The purpose of this paper was to contribute to understanding of the crucial role of emotion in work motivation by testing a conceptual model developed by Seo, Barrett, and Bartunek (2004) that predicted the impacts of core affect on three behavioral outcomes of work motivation, generative-defensive orientation, effort, and persistence. We tested the model using an Internet-based investment simulation combined with an experience sampling procedure. Consistent with the predictions of the model, pleasantness was positively related to all three of the predicted indices. For the most part, these effects occurred indirectly via its relationships with expectancy, valence, and progress judgment components. Also as predicted by the model, activation was directly and positively related to effort. PMID:21785527

  3. a Conceptual Model for the Representation of Landforms Using Ontology Design Patterns

    NASA Astrophysics Data System (ADS)

    Guilbert, Eric; Moulin, Bernard; Cortés Murcia, Andrés

    2016-06-01

    A landform is an area of a terrain with its own recognisable shape. Its definition is often qualitative and inherently vague. Hence landforms are difficult to formalise in view of their extraction from a DTM. This paper presents a two-level framework for the representation of landforms. The objective is to provide a structure where landforms can be conceptually designed according to a common model which can be implemented. It follows the principle that landforms are not defined by geometrical characteristics but by salient features perceived by people. Hence, these salient features define a skeleton around which the landform is built. The first level of our model defines general concepts forming a landform prototype while the second level provides a model for the translation of these concepts and landform extraction on a DTM. The model is still under construction and preliminary results together with current developments are also presented.

  4. Prospects for Advanced RF Theory and Modeling

    SciTech Connect

    Batchelor, D.B.

    1999-04-12

    This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

  5. Prospects for advanced RF theory and modeling

    NASA Astrophysics Data System (ADS)

    Batchelor, D. B.

    1999-09-01

    This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

  6. Advanced modeling of prompt fission neutrons

    SciTech Connect

    Talou, Patrick

    2009-01-01

    Theoretical and numerical studies of prompt fission neutrons are presented. The main results of the Los Alamos model often used in nuclear data evaluation work are reviewed briefly, and a preliminary assessment of uncertainties associated with the evaluated prompt fission neutron spectrum for n (0.5 MeV)+{sup 239}Pu is discussed. Advanced modeling of prompt fission neutrons is done by Monte Carlo simulations of the evaporation process of the excited primary fission fragments. The successive emissions of neutrons are followed in the statistical formalism framework, and detailed information, beyond average quantities, can be inferred. This approach is applied to the following reactions: {sup 252}Cf (sf), n{sub th} + {sup 239}Pu, n (0.5 MeV)+{sup 235}U, and {sup 236}Pu (sf). A discussion on the merits and present limitations of this approach concludes this presentation.

  7. Studying the teaching of kindness: A conceptual model for evaluating kindness education programs in schools.

    PubMed

    Kaplan, Deanna M; deBlois, Madeleine; Dominguez, Violeta; Walsh, Michele E

    2016-10-01

    Recent research suggests that school-based kindness education programs may benefit the learning and social-emotional development of youth and may improve school climate and school safety outcomes. However, how and to what extent kindness education programming influences positive outcomes in schools is poorly understood, and such programs are difficult to evaluate in the absence of a conceptual model for studying their effectiveness. In partnership with Kind Campus, a widely adopted school-based kindness education program that uses a bottom-up program framework, a methodology called concept mapping was used to develop a conceptual model for evaluating school-based kindness education programs from the input of 123 middle school students and approximately 150 educators, school professionals, and academic scholars. From the basis of this model, recommendations for processes and outcomes that would be useful to assess in evaluations of kindness education programs are made, and areas where additional instrument development may be necessary are highlighted. The utility of the concept mapping method as an initial step in evaluating other grassroots or non-traditional educational programming is also discussed.

  8. Advancing Coupled Human-Earth System Models: The Integrated Ecosystem Demography Model (iED) Project

    NASA Astrophysics Data System (ADS)

    Hurtt, G. C.; Chini, L. P.; Clarke, L.; Calvin, K. V.; Chambers, J. Q.; Dubayah, R.; Dolan, K.; Edmonds, J. A.; Fisk, J. P.; Flanagan, S.; Frolking, S.; Janetos, A. C.; LePage, Y.; Morton, D. C.; Patel, P.; Rourke, O.; Sahajpal, R.; Thomson, A. M.; Wise, M.; Ying, Q.

    2012-12-01

    Recent studies with integrated assessment models, models linking human and natural systems at a global scale, highlight the importance of terrestrial systems in climate stabilization efforts. Here we introduce a new modeling framework iED, designed to link advanced remote sensing data (active and passive.), height-structured terrestrial ecosystem dynamics (ED), gridded land-use change projections (GLM), and integrated assessment modeling (GCAM) into a single coupled modeling framework with unprecedented spatial resolution and process-level detail. Our research aims to reduce uncertainties associated with forest modeling within integrated assessments, and to quantify the impacts of climate change on forest growth, mortality, and productivity for integrated assessments of terrestrial carbon management. iED is being used to address key science questions including: (1) What are the opportunities for land-use strategies such as afforestation or woody bioenergy crop production to contribute to stabilization of atmospheric CO2 concentrations? (2) How could potentially altered disturbance rates from tropical cyclones and Amazonian fires affect vegetation, carbon stocks and fluxes, and the development of climate change mitigation strategies? (3) What are the linked remote sensing/ecosystem modeling requirements for improving integrated assessments of climate mitigation strategies? With its strong connections to data and conceptual linkages to other models in development, iED is also designed to inform the next generation of remote sensing and integrated Earth system modeling efforts.

  9. A Hydrological Model To Bridge The Gap Between Conceptual and Physically Based Approaches

    NASA Astrophysics Data System (ADS)

    Lempert, M.; Ostrowski, M.; Blöschl, G.

    In the last decade it has become evident that models are needed to account for more realistic physical assumptions and for improved data availability and computational facilities. In general it seems to be a dominant objective to better account for nonlin- earity and for less uncertain parameter identification. This allows its application also to ungaged catchments. To account for these objectives and for improved computa- tional boundary conditions a new model has been developed, tested and validated at Darmstadt University of Technology. The model is a quasi non linear model, it uses GIS provided data and includes physically based (not physical) model parameters, quite readily available from digitally stored information. Surface runoff determined after physically based non linear soil moisture modelling is routed with the kinematic cascade approach according to digital elevation grid models while sub-surface flow is routed through linear conceptual modules. The model uses generally accepted param- eters for soil moisture modelling including vegetation canopy such as total porosity, field cvapacity, wilting point, hydraulic conductivities and leaf area index and canopy coverage. The model has been successfully applied to several test sites and catchments at local, micro and lower macro scales. It is the objective of the paper to - explain the background of model development - briefly explain algorithms - discuss model parameter identification - present case study results

  10. Automatic generation of conceptual database design tools from data model specifications

    SciTech Connect

    Hong, Shuguang.

    1989-01-01

    The problems faced in the design and implementation of database software systems based on object-oriented data models are similar to that of other software design, i.e., difficult, complex, yet redundant effort. Automatic generation of database software system has been proposed as a solution to the problems. In order to generate database software system for a variety of object-oriented data models, two critical issues: data model specification and software generation, must be addressed. SeaWeed is a software system that automatically generates conceptual database design tools from data model specifications. A meta model has been defined for the specification of a class of object-oriented data models. This meta model provides a set of primitive modeling constructs that can be used to express the semantics, or unique characteristics, of specific data models. Software reusability has been adopted for the software generation. The technique of design reuse is utilized to derive the requirement specification of the software to be generated from data model specifications. The mechanism of code reuse is used to produce the necessary reusable software components. This dissertation presents the research results of SeaWeed including the meta model, data model specification, a formal representation of design reuse and code reuse, and the software generation paradigm.

  11. Advanced neutron source reactor conceptual safety analysis report, three-element-core design: Chapter 15, accident analysis

    SciTech Connect

    Chen, N.C.J.; Wendel, M.W.; Yoder, G.L.; Harrington, R.M.

    1996-02-01

    In order to utilize reduced enrichment fuel, the three-element-core design for the Advanced Neutron Source has been proposed. The proposed core configuration consists of inner, middle, and outer elements, with the middle element offset axially beneath the inner and outer elements, which are axially aligned. The three-element-core RELAP5 model assumes that the reactor hardware is changed only within the core region, so that the loop piping, heat exchangers, and pumps remain as assumed for the two-element-core configuration. To assess the impact of changes in the core region configuration and the thermal-hydraulic steady-state conditions, the safety analysis has been updated. This report gives the safety margins for the loss-of-off-site power and pressure-boundary fault accidents based on the RELAP5 results. AU margins are greater for the three-element-core simulations than those calculated for the two-element core.

  12. Advancing an Information Model for Environmental Observations

    NASA Astrophysics Data System (ADS)

    Horsburgh, J. S.; Aufdenkampe, A. K.; Hooper, R. P.; Lehnert, K. A.; Schreuders, K.; Tarboton, D. G.; Valentine, D. W.; Zaslavsky, I.

    2011-12-01

    have been modified to support data management for the Critical Zone Observatories (CZOs). This paper will present limitations of the existing information model used by the CUAHSI HIS that have been uncovered through its deployment and use, as well as new advances to the information model, including: better representation of both in situ observations from field sensors and observations derived from environmental samples, extensibility in attributes used to describe observations, and observation provenance. These advances have been developed by the HIS team and the broader scientific community and will enable the information model to accommodate and better describe wider classes of environmental observations and to better meet the needs of the hydrologic science and CZO communities.

  13. Physically-based modeling of water exchange between surface water and groundwater : Conceptual and applied simulations (Invited)

    NASA Astrophysics Data System (ADS)

    Therrien, R.; Brunner, P.; Simmons, C.; Cook, P. G.

    2009-12-01

    There is an increasing need to characterize and manage groundwater and surface water as an integrated system, for example to address the sustainability of water resources for humans and ecosystems. Recent advances in the integrated simulation of surface and subsurface fluid flow and solute transport have allowed to investigate in greater detail water cycling at the watershed scale, in particular exchanges at the interface between surface and subsurface. One example of recent advances in simulation capacities is the HydroGeoSphere model, which can simulate fully-coupled 3D variably-saturated flow in the subsurface, 2D surface runoff and 1D channel flow, along with the advective-dispersive transport of reactive contaminants in the subsurface and surface domains. The surface, channel and subsurface water domains are fully integrated by assembling and solving one system of discrete algebraic equations, such that surface flow rates and water depths, channel flow rates and water depths, subsurface pressure heads, saturations and velocities, as well as water fluxes between continua, are determined simultaneously. This integrated model can be used to address the impact of heterogeneity of natural materials on surface and subsurface exchanges, as well as investigate the spatial and temporal dynamics of water and solute exchange between the surface and subsurface. Because it is physically-based and accounts for a large number of physical processes, it can also be used in a prospective way to identify conditions where simplified and less computationally-expensive approaches are appropriate. In this context, we present some recent applications of HydroGeoSphere to investigate exchange processes at the interface between the surface and subsurface. Some applications are conceptual and the model is used as a learning tool to gain understanding of exchange between surface and subsurface flow, for example for connected and disconnected losing streams. These simulations also

  14. Cancer Outcomes in Hispanics/Latinos in the United States: An Integrative Review and Conceptual Model of Determinants of Health

    PubMed Central

    Yanez, Betina; McGinty, Heather L.; Buitrago, Diana; Ramirez, Amelie G.; Penedo, Frank J.

    2015-01-01

    Cancer is the leading cause of death among Hispanics. Compared to non-Hispanic Whites, Hispanics are more likely to be diagnosed with advanced stages of disease and experience poor quality of life following a cancer diagnosis. Cancer outcomes are influenced by a confluence of social, cultural, behavioral and biological factors. Yet, much of the behavioral and psychosocial research in oncology has focused on non-Hispanic Whites, thus limiting our understanding of the potential web of factors that can influence cancer-related outcomes among Hispanics. Furthermore, features of Hispanic ethnicity and culture may influence and interact with, social, psychosocial, health care, disease-specific, and medical factors known to influence cancer-related outcomes, yet very few studies have integrated Hispanic cultural processes when addressing cancer-related outcomes for this ethnic group. Guided by the extant literature in oncology, Hispanic culture and health, and previously established models of determinants of minority health, we present a conceptual model that highlights the interplay of social, cultural, psychosocial, disease-specific, health care, and medical factors as determinants of cancer outcomes (morbidity, mortality, quality of life) and review key evidence of how features of Hispanic culture may influence cancer outcomes and contribute to the disparate outcomes observed in Hispanic cancer samples relative to non-Hispanic Whites. Finally, we conclude with a discussion of future research opportunities and existing challenges to researching oncology outcomes among Hispanics. PMID:27429867

  15. A conceptual framework for restoration of threatened plants: the effective model of American chestnut (Castanea dentata) reintroduction.

    PubMed

    Jacobs, Douglass F; Dalgleish, Harmony J; Nelson, C Dana

    2013-01-01

    We propose a conceptual framework for restoration of threatened plant species that encourages integration of technological, ecological, and social spheres. A sphere encompasses ideas relevant to restoration and the people working within similar areas of influence or expertise. Increased capacity within a sphere and a higher degree of coalescing among spheres predict a greater probability of successful restoration. We illustrate this with Castanea dentata, a foundation forest tree in North America that was annihilated by an introduced pathogen; the species is a model that effectively merges biotechnology, reintroduction biology, and restoration ecology. Because of C. dentata's ecological and social importance, scientists have aggressively pursued blight resistance through various approaches. We summarize recent advancements in tree breeding and biotechnology that have emerged from C. dentata research, and describe their potential to bring new tools to bear on socio-ecological restoration problems. Successful reintroduction of C. dentata will also depend upon an enhanced understanding of its ecology within contemporary forests. We identify a critical need for a deeper understanding of societal influences that may affect setting and achieving realistic restoration goals. Castanea dentata may serve as an important model to inform reintroduction of threatened plant species in general and foundation forest trees in particular.

  16. Conceptual Model of Military Women's Life Events and Well-Being.

    PubMed

    Segal, Mady W; Lane, Michelle D

    2016-01-01

    This article presents a life course conceptual model and applies it to the study of military women's experiences and the effect of those life events on their well-being. Of special concern are the effects on women serving in direct combat jobs, as well as in any specialties operating in a hostile environment. Drawing on previous research, the model considers and gives examples of how a woman's well-being is affected by events in her military career, her family life, and other areas of life. The article emphasizes the effects of intersections of multiple events, as well as how the effects on well-being are mediated or moderated by other factors, including individual characteristics, military contextual variables, and resources. The analysis also includes the impacts of preventative and treatment interventions, as well as of policies, programs, and practices. Based on the model and on previous research, questions for future research are posed.

  17. Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum

    SciTech Connect

    Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

    1980-05-30

    Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes.

  18. Conceptualizing Changes in Behavior in Intervention Research: The Range of Possible Changes Model

    PubMed Central

    De Los Reyes, Andres; Kazdin, Alan E.

    2011-01-01

    An international movement has focused on identifying evidence-based interventions: Interventions that were developed to change psychological constructs, and have evidence from controlled studies on their behalf. However, inconsistent findings within individual intervention studies and among multiple studies of the same intervention raise critical problems for interpreting the evidence, and deciding when and whether an intervention is evidence-based. A theoretical and methodological framework (Range of Possible Changes [RPC] Model) is proposed to guide the study of change in intervention research. We recommend that future quantitative reviews of the research literature use the RPC Model to conceptualize, examine, and classify the available evidence for interventions. Further, future research should adopt the RPC Model to both develop theory-driven hypotheses and conduct examinations of the instances in which interventions may or may not change psychological constructs. PMID:16802881

  19. Conceptual hydrogeological model of volcanic Easter Island (Chile) after chemical and isotopic surveys

    NASA Astrophysics Data System (ADS)

    Herrera, Christian; Custodio, Emilio

    2008-11-01

    Most human activities and hydrogeological information on small young volcanic islands are near the coastal area. There are almost no hydrological data from inland areas, where permanent springs and/or boreholes may be rare or nonexistent. A major concern is the excessive salinity of near-the-coast wells. Obtaining a conceptual hydrogeological model is crucial for groundwater resources development and management. Surveys of water seepages and rain for chemical and environmental isotope contents may provide information on the whole island groundwater flow conditions, in spite of remaining geological and hydrogeological uncertainties. New data from Easter Island (Isla de Pascua), in the Pacific Ocean, are considered. Whether Easter Island has a central low permeability volcanic “core” sustaining an elevated water table remains unknown. Average recharge is estimated at 300-400 mm/year, with a low salinity of 15-50 mg/L Cl. There is an apron of highly permeable volcanics that extends to the coast. The salinity of near-the-coast wells, >1,000 mg/L Cl, is marine in origin. This is the result of a thick mixing zone of island groundwater and encroached seawater, locally enhanced by upconings below pumping wells. This conceptual model explains what is observed, in the absence of inland boreholes and springs.

  20. Applying the dual-isotope conceptual model to interpret physiological trends under uncontrolled conditions.

    PubMed

    Barnard, H R; Brooks, J R; Bond, B J

    2012-10-01

    The inter-relationships among δ(13)C and δ(18)O in tree ring cellulose and ring width have the potential to illuminate long-term physiological and environmental information in forest stands that have not been monitored. We examine how within-stand competition and environmental gradients affect ring widths and the stable isotopes of cellulose. We utilize a natural climate gradient across a catchment dominated by Douglas-fir and temporal changes in climate over an 8-year period. We apply a dual-isotope approach to infer physiological response of trees in differing crown dominance classes to temporal and spatial changes in environmental conditions using a qualitative conceptual model of the (13)C-(18)O relationship and by normalizing the data to minimize other variance. The δ(13)C and δ(18)O of cellulose were correlated with year-to-year variation in relative humidity and consistent with current isotope theory. Using a qualitative conceptual model of the (13)C-(18)O relationship and physiological knowledge about the species, we interpreted these changes as stomatal conductance responses to evaporative demand. Spatial variance between plots was not strong and seemed related to leaf nitrogen rather than any other environmental variable. Dominant trees responded to environmental gradients more consistently with current isotope theory as compared with other classes within the same stand. We found a correlation of stable isotopes with environmental variables is useful for assessing the impacts of environmental change over short time series and where growth varies only minimally with climate.