WorldWideScience

Sample records for detailed physical modeling

  1. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  2. Optimizing a physical security configuration using a highly detailed simulation model

    NARCIS (Netherlands)

    Marechal, T.M.A.; Smith, A.E.; Ustun, V.; Smith, J.S.; Lefeber, A.A.J.; Badiru, A.B.; Thomas, M.U.

    2009-01-01

    This research is focused on using a highly detailed simulation model to create a physical security system to prevent intrusions in a building. Security consists of guards and security cameras. The problem is represented as a binary optimization problem. A new heuristic is proposed to do the security

  3. Detailed physical properties prediction of pure methyl esters for biodiesel combustion modeling

    International Nuclear Information System (INIS)

    An, H.; Yang, W.M.; Maghbouli, A.; Chou, S.K.; Chua, K.J.

    2013-01-01

    Highlights: ► Group contribution methods from molecular level have been used for the prediction. ► Complete prediction of the physical properties for 5 methyl esters has been done. ► The predicted results can be very useful for biodiesel combustion modeling. ► Various models have been compared and the best model has been identified. ► Predicted properties are over large temperature ranges with excellent accuracies. -- Abstract: In order to accurately simulate the fuel spray, atomization, combustion and emission formation processes of a diesel engine fueled with biodiesel, adequate knowledge of biodiesel’s physical properties is desired. The objective of this work is to do a detailed physical properties prediction for the five major methyl esters of biodiesel for combustion modeling. The physical properties considered in this study are: normal boiling point, critical properties, vapor pressure, and latent heat of vaporization, liquid density, liquid viscosity, liquid thermal conductivity, gas diffusion coefficients and surface tension. For each physical property, the best prediction model has been identified, and very good agreements have been obtained between the predicted results and the published data where available. The calculated results can be used as key references for biodiesel combustion modeling.

  4. A detailed physical model for ion implant induced damage in silicon

    International Nuclear Information System (INIS)

    Tian, S.; Morris, M.F.; Morris, S.J.; Obradovic, B.; Wang, G.; Tasch, A.F.

    1998-01-01

    A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF 2 , and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model has been incorporated in the UT-MARLOWE ion implantation simulator, and has been developed primarily for use in engineering workstations. This damage model is the most physical model in the literature to date within the framework of the binary collision approximation (BCA), and provides the required, accurate as-implanted impurity profiles and damage profiles for transient enhanced diffusion (TED) simulation

  5. Detailed clinical models: a review.

    Science.gov (United States)

    Goossen, William; Goossen-Baremans, Anneke; van der Zel, Michael

    2010-12-01

    Due to the increasing use of electronic patient records and other health care information technology, we see an increase in requests to utilize these data. A highly level of standardization is required during the gathering of these data in the clinical context in order to use it for analyses. Detailed Clinical Models (DCM) have been created toward this purpose and several initiatives have been implemented in various parts of the world to create standardized models. This paper presents a review of DCM. Two types of analyses are presented; one comparing DCM against health care information architectures and a second bottom up approach from concept analysis to representation. In addition core parts of the draft ISO standard 13972 on DCM are used such as clinician involvement, data element specification, modeling, meta information, and repository and governance. SIX INITIATIVES WERE SELECTED: Intermountain Healthcare, 13606/OpenEHR Archetypes, Clinical Templates, Clinical Contents Models, Health Level 7 templates, and Dutch Detailed Clinical Models. Each model selected was reviewed for their overall development, involvement of clinicians, use of data types, code bindings, expressing semantics, modeling, meta information, use of repository and governance. Using both a top down and bottom up approach to comparison reveals many commonalties and differences between initiatives. Important differences include the use of or lack of a reference model and expressiveness of models. Applying clinical data element standards facilitates the use of conceptual DCM models in different technical representations.

  6. Clinical professional governance for detailed clinical models.

    Science.gov (United States)

    Goossen, William; Goossen-Baremans, Anneke

    2013-01-01

    This chapter describes the need for Detailed Clinical Models for contemporary Electronic Health Systems, data exchange and data reuse. It starts with an explanation of the components related to Detailed Clinical Models with a brief summary of knowledge representation, including terminologies representing clinic relevant "things" in the real world, and information models that abstract these in order to let computers process data about these things. Next, Detailed Clinical Models are defined and their purpose is described. It builds on existing developments around the world and accumulates in current work to create a technical specification at the level of the International Standards Organization. The core components of properly expressed Detailed Clinical Models are illustrated, including clinical knowledge and context, data element specification, code bindings to terminologies and meta-information about authors, versioning among others. Detailed Clinical Models to date are heavily based on user requirements and specify the conceptual and logical levels of modelling. It is not precise enough for specific implementations, which requires an additional step. However, this allows Detailed Clinical Models to serve as specifications for many different kinds of implementations. Examples of Detailed Clinical Models are presented both in text and in Unified Modelling Language. Detailed Clinical Models can be positioned in health information architectures, where they serve at the most detailed granular level. The chapter ends with examples of projects that create and deploy Detailed Clinical Models. All have in common that they can often reuse materials from earlier projects, and that strict governance of these models is essential to use them safely in health care information and communication technology. Clinical validation is one point of such governance, and model testing another. The Plan Do Check Act cycle can be applied for governance of Detailed Clinical Models

  7. Detailed modeling of mountain wave PSCs

    Directory of Open Access Journals (Sweden)

    S. Fueglistaler

    2003-01-01

    Full Text Available Polar stratospheric clouds (PSCs play a key role in polar ozone depletion. In the Arctic, PSCs can occur on the mesoscale due to orographically induced gravity waves. Here we present a detailed study of a mountain wave PSC event on 25-27 January 2000 over Scandinavia. The mountain wave PSCs were intensively observed by in-situ and remote-sensing techniques during the second phase of the SOLVE/THESEO-2000 Arctic campaign. We use these excellent data of PSC observations on 3 successive days to analyze the PSCs and to perform a detailed comparison with modeled clouds. We simulated the 3-dimensional PSC structure on all 3 days with a mesoscale numerical weather prediction (NWP model and a microphysical box model (using best available nucleation rates for ice and nitric acid trihydrate particles. We show that the combined mesoscale/microphysical model is capable of reproducing the PSC measurements within the uncertainty of data interpretation with respect to spatial dimensions, temporal development and microphysical properties, without manipulating temperatures or using other tuning parameters. In contrast, microphysical modeling based upon coarser scale global NWP data, e.g. current ECMWF analysis data, cannot reproduce observations, in particular the occurrence of ice and nitric acid trihydrate clouds. Combined mesoscale/microphysical modeling may be used for detailed a posteriori PSC analysis and for future Arctic campaign flight and mission planning. The fact that remote sensing alone cannot further constrain model results due to uncertainities in the interpretation of measurements, underlines the need for synchronous in-situ PSC observations in campaigns.

  8. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon

    2010-01-01

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...... by the mesh densities, the distribution of computational cells, the physical model and time steps used in the simulations. The findings of the investigations will be used as guidance for creation of CFD models for optimal design of smart solar tanks....

  9. CADDIS Volume 2. Sources, Stressors and Responses: Physical Habitat - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the Physical Habitat module, when to list Physical Habitat as a candidate cause, ways to measure Physical Habitat, simple and detailed conceptual diagrams for Physical Habitat, Physical Habitat module references and literature reviews.

  10. Cleaner combustion developing detailed chemical kinetic models

    CERN Document Server

    Battin-Leclerc, Frédérique; Simmie, John M

    2013-01-01

    This book describes the reactive chemistry of minor pollutants within extensively validated detailed mechanisms for traditional fuels, and also for innovative surrogates, describing the complex chemistry of new, environmentally important bio-fuels.

  11. Detailed CFD Modelling of Open Refrigerated Display Cabinets

    Directory of Open Access Journals (Sweden)

    Pedro Dinis Gaspar

    2012-01-01

    Full Text Available A comprehensive and detailed computational fluid dynamics (CFDs modelling of air flow and heat transfer in an open refrigerated display cabinet (ORDC is performed in this study. The physical-mathematical model considers the flow through the internal ducts, across fans and evaporator, and includes the thermal response of food products. The air humidity effect and thermal radiation heat transfer between surfaces are taken into account. Experimental tests were performed to characterize the phenomena near physical extremities and to validate the numerical predictions of air temperature, relative humidity, and velocity. Numerical and experimental results comparison reveals the predictive capabilities of the computational model for the optimized conception and development of this type of equipments. Numerical predictions are used to propose geometrical and functional parametric studies that improve thermal performance of the ORDC and consequently food safety.

  12. Mathematical Model of Induction Heating Processes in Axial Symmetric Inductor-Detail Systems

    Directory of Open Access Journals (Sweden)

    Maik Streblau

    2014-05-01

    Full Text Available The wide variety of models for analysis of processes in the inductor-detail systems makes it necessary to summarize them. This is a difficult task because of the variety of inductor-detail system configurations. This paper aims to present a multi physics mathematical model for complex analysis of electromagnetic and thermal fields in axial symmetric systems inductor-detail.

  13. Detailed Chemical Kinetic Modeling of Hydrazine Decomposition

    Science.gov (United States)

    Meagher, Nancy E.; Bates, Kami R.

    2000-01-01

    The purpose of this research project is to develop and validate a detailed chemical kinetic mechanism for gas-phase hydrazine decomposition. Hydrazine is used extensively in aerospace propulsion, and although liquid hydrazine is not considered detonable, many fuel handling systems create multiphase mixtures of fuels and fuel vapors during their operation. Therefore, a thorough knowledge of the decomposition chemistry of hydrazine under a variety of conditions can be of value in assessing potential operational hazards in hydrazine fuel systems. To gain such knowledge, a reasonable starting point is the development and validation of a detailed chemical kinetic mechanism for gas-phase hydrazine decomposition. A reasonably complete mechanism was published in 1996, however, many of the elementary steps included had outdated rate expressions and a thorough investigation of the behavior of the mechanism under a variety of conditions was not presented. The current work has included substantial revision of the previously published mechanism, along with a more extensive examination of the decomposition behavior of hydrazine. An attempt to validate the mechanism against the limited experimental data available has been made and was moderately successful. Further computational and experimental research into the chemistry of this fuel needs to be completed.

  14. Detailed Performance Model for Photovoltaic Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tian, H.; Mancilla-David, F.; Ellis, K.; Muljadi, E.; Jenkins, P.

    2012-07-01

    This paper presents a modified current-voltage relationship for the single diode model. The single-diode model has been derived from the well-known equivalent circuit for a single photovoltaic cell. The modification presented in this paper accounts for both parallel and series connections in an array.

  15. FIM measurement properties and Rasch model details.

    Science.gov (United States)

    Wright, B D; Linacre, J M; Smith, R M; Heinemann, A W; Granger, C V

    1997-12-01

    To summarize, we take issue with the criticisms of Dickson & Köhler for two main reasons: 1. Rasch analysis provides a model from which to approach the analysis of the FIM, an ordinal scale, as an interval scale. The existence of examples of items or individuals which do not fit the model does not disprove the overall efficacy of the model; and 2. the principal components analysis of FIM motor items as presented by Dickson & Köhler tends to undermine rather than support their argument. Their own analyses produce a single major factor explaining between 58.5 and 67.1% of the variance, depending upon the sample, with secondary factors explaining much less variance. Finally, analysis of item response, or latent trait, is a powerful method for understanding the meaning of a measure. However, it presumes that item scores are accurate. Another concern is that Dickson & Köhler do not address the issue of reliability of scoring the FIM items on which they report, a critical point in comparing results. The Uniform Data System for Medical Rehabilitation (UDSMRSM) expends extensive effort in the training of clinicians of subscribing facilities to score items accurately. This is followed up with a credentialing process. Phase 1 involves the testing of individual clinicians who are submitting data to determine if they have achieved mastery over the use of the FIM instrument. Phase 2 involves examining the data for outlying values. When Dickson & Köhler investigate more carefully the application of the Rasch model to their FIM data, they will discover that the results presented in their paper support rather than contradict their application of the Rasch model! This paper is typical of supposed refutations of Rasch model applications. Dickson & Köhler will find that idiosyncrasies in their data and misunderstandings of the Rasch model are the only basis for a claim to have disproven the relevance of the model to FIM data. The Rasch model is a mathematical theorem (like

  16. Detailed simulation of morphodynamics : 1. Hydrodynamic model

    NARCIS (Netherlands)

    Nabi, M.; De Vriend, H.J.; Mosselman, E.; Sloff, C.J.; Shimizu, Y.

    2012-01-01

    We present a three-dimensional high-resolution hydrodynamic model for unsteady incompressible flow over an evolving bed topography. This is achieved by using a multilevel Cartesian grid technique that allows the grid to be refined in high-gradient regions and in the vicinity of the river bed. The

  17. Physical modeling of rock

    International Nuclear Information System (INIS)

    Cheney, J.A.

    1981-01-01

    The problems of statisfying similarity between a physical model and the prototype in rock wherein fissures and cracks place a role in physical behavior is explored. The need for models of large physical dimensions is explained but also testing of models of the same prototype over a wide range of scales is needed to ascertain the influence of lack of similitude of particular parameters between prototype and model. A large capacity centrifuge would be useful in that respect

  18. Physical Chemistry of Bile: Detailed Pathogenesis of Cholelithiasis.

    Science.gov (United States)

    Itani, Malak; Dubinsky, Theodore J

    2017-09-01

    Despite the overwhelming prevalence of cholelithiasis, many health care professionals are not familiar with the basic pathophysiology of gallstone formation. This article provides an overview of the biochemical pathways related to bile, with a focus on the physical chemistry of bile. We describe the important factors in bile synthesis and secretion that affect the composition of bile and consequently its liquid state. Within this biochemical background lies the foundation for understanding the clinical and sonographic manifestation of cholelithiasis, including the pathophysiology of cholesterol crystallization, gallbladder sludge, and gallstones. There is a brief discussion of the clinical manifestations of inflammatory and obstructive cholestasis and the impact on bile metabolism and subsequently on liver function tests. Despite being the key modality in diagnosing cholelithiasis, ultrasound has a limited role in the characterization of stone composition.

  19. A detailed BWR recirculation loop model for RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Araiza-Martínez, Enrique, E-mail: enrique.araiza@inin.gob.mx; Ortiz-Villafuerte, Javier, E-mail: javier.ortiz@inin.gob.mx; Castillo-Durán, Rogelio, E-mail: rogelio.castillo@inin.gob.mx

    2017-01-15

    Highlights: • A new detailed BWR recirculation loop model was developed for RELAP. • All jet pumps, risers, manifold, suction and control valves, and recirculation pump are modeled. • Model is tested against data from partial blockage of two jet pumps. • For practical applications, simulation results showed good agreement with available data. - Abstract: A new detailed geometric model of the whole recirculation loop of a BWR has been developed for the code RELAP. This detailed model includes the 10 jet pumps, 5 risers, manifold, suction and control valves, and the recirculation pump, per recirculation loop. The model is tested against data from an event of partial blockage at the entrance nozzle of one jet pump in both recirculation loops. For practical applications, simulation results showed good agreement with data. Then, values of parameters considered as figure of merit (reactor power, dome pressure, core flow, among others) for this event are compared against those from the common 1 jet pump per loop model. The results show that new detailed model led to a closer prediction of the reported power change. The detailed recirculation loop model can provide more reliable boundary condition data to a CFD models for studies of, for example, flow induced vibration, wear, and crack initiation.

  20. Identification of physical models

    DEFF Research Database (Denmark)

    Melgaard, Henrik

    1994-01-01

    of the model with the available prior knowledge. The methods for identification of physical models have been applied in two different case studies. One case is the identification of thermal dynamics of building components. The work is related to a CEC research project called PASSYS (Passive Solar Components......The problem of identification of physical models is considered within the frame of stochastic differential equations. Methods for estimation of parameters of these continuous time models based on descrete time measurements are discussed. The important algorithms of a computer program for ML or MAP...... design of experiments, which is for instance the design of an input signal that are optimal according to a criterion based on the information provided by the experiment. Also model validation is discussed. An important verification of a physical model is to compare the physical characteristics...

  1. Probabilistic Model for Fatigue Crack Growth in Welded Bridge Details

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, Thierry

    2013-01-01

    In the present paper a probabilistic model for fatigue crack growth in welded steel details in road bridges is presented. The probabilistic model takes the influence of bending stresses in the joints into account. The bending stresses can either be introduced by e.g. misalignment or redistribution...... of stresses in the structure. The fatigue stress ranges are estimated from traffic measurements and a generic bridge model. Based on the probabilistic models for the resistance and load the reliability is estimated for a typical welded steel detail. The results show that large misalignments in the joints can...

  2. GEOMETRIC MODELLING OF TREE ROOTS WITH DIFFERENT LEVELS OF DETAIL

    Directory of Open Access Journals (Sweden)

    J. I. Guerrero Iñiguez

    2017-09-01

    Full Text Available This paper presents a geometric approach for modelling tree roots with different Levels of Detail, suitable for analysis of the tree anchoring, potentially occupied underground space, interaction with urban elements and damage produced and taken in the built-in environment. Three types of tree roots are considered to cover several species: tap root, heart shaped root and lateral roots. Shrubs and smaller plants are not considered, however, a similar approach can be considered if the information is available for individual species. The geometrical approach considers the difficulties of modelling the actual roots, which are dynamic and almost opaque to direct observation, proposing generalized versions. For each type of root, different geometric models are considered to capture the overall shape of the root, a simplified block model, and a planar or surface projected version. Lower detail versions are considered as compatibility version for 2D systems while higher detail models are suitable for 3D analysis and visualization. The proposed levels of detail are matched with CityGML Levels of Detail, enabling both analysis and aesthetic views for urban modelling.

  3. Geometric Modelling of Tree Roots with Different Levels of Detail

    Science.gov (United States)

    Guerrero Iñiguez, J. I.

    2017-09-01

    This paper presents a geometric approach for modelling tree roots with different Levels of Detail, suitable for analysis of the tree anchoring, potentially occupied underground space, interaction with urban elements and damage produced and taken in the built-in environment. Three types of tree roots are considered to cover several species: tap root, heart shaped root and lateral roots. Shrubs and smaller plants are not considered, however, a similar approach can be considered if the information is available for individual species. The geometrical approach considers the difficulties of modelling the actual roots, which are dynamic and almost opaque to direct observation, proposing generalized versions. For each type of root, different geometric models are considered to capture the overall shape of the root, a simplified block model, and a planar or surface projected version. Lower detail versions are considered as compatibility version for 2D systems while higher detail models are suitable for 3D analysis and visualization. The proposed levels of detail are matched with CityGML Levels of Detail, enabling both analysis and aesthetic views for urban modelling.

  4. Models in physics teaching

    DEFF Research Database (Denmark)

    Kneubil, Fabiana Botelho

    2016-01-01

    In this work we show an approach based on models, for an usual subject in an introductory physics course, in order to foster discussions on the nature of physical knowledge. The introduction of elements of the nature of knowledge in physics lessons has been emphasised by many educators and one uses...... the case of metals to show the theoretical and phenomenological dimensions of physics. The discussion is made by means of four questions whose answers cannot be reached neither for theoretical elements nor experimental measurements. Between these two dimensions it is necessary to realise a series...... of reasoning steps to deepen the comprehension of microscopic concepts, such as electrical resistivity, drift velocity and free electrons. When this approach is highlighted, beyond the physical content, aspects of its nature become explicit and may improve the structuring of knowledge for learners...

  5. Detailed modeling of superconducting magnetic energy storage (SMES) system

    NARCIS (Netherlands)

    Chen, L.; Liu, Y.; Arsoy, A.B.; Ribeiro, P.F.; Steurer, M.; Iravani, M.R.

    2006-01-01

    This paper presents a detailed model for simulation of a Superconducting Magnetic Energy Storage (SMES) system. SMES technology has the potential to bring real power storage characteristic to the utility transmission and distribution systems. The principle of SMES system operation is reviewed in

  6. Detailed behavioral modeling of bang-bang phase detectors

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Andreani, Pietro; Keil, U. D.

    2006-01-01

    In this paper, the metastability of current-mode logic (CML) latches and flip-flops is studied in detail. Based on the results of this analysis, a behavioral model of bang-bang phase detectors (BBPDs) is proposed, which is able to reliably capture the critical deadzone effect. The impact of jitter...

  7. Level of detail in 3D city models

    NARCIS (Netherlands)

    Biljecki, F.

    2017-01-01

    The concept of level of detail (LOD) describes the content of 3D city models and it plays an essential role during their life cycle. On one hand it comes akin to the concepts of scale in cartography and LOD in computer graphics, on the other hand it is a standalone concept that requires attention.

  8. Phenomenological modeling of combustion and NOx emissions using detailed tabulated chemistry methods in diesel engines

    OpenAIRE

    Rezaei, R.; Dinkelacker, F.; Tilch, B.; Delebinski, T.; Brauer, M.

    2016-01-01

    Enhancing the predictive quality of engine models, while maintaining an affordable computational cost, is of great importance. In this study, a phenomenological combustion and a tabulated NOx model, focusing on efficient modeling and improvement of computational effort, is presented. The proposed approach employs physical and chemical sub-models for local processes such as injection, spray formation, ignition, combustion, and NOx formation, being based on detailed tabulated chemistry methods....

  9. A Statistical Model for Synthesis of Detailed Facial Geometry

    OpenAIRE

    Golovinskiy, Aleksey; Matusik, Wojciech; Pfister, Hanspeter; Rusinkiewicz, Szymon; Funkhouser, Thomas

    2006-01-01

    Detailed surface geometry contributes greatly to the visual realism of 3D face models. However, acquiring high-resolution face geometry is often tedious and expensive. Consequently, most face models used in games, virtual reality, or computer vision look unrealistically smooth. In this paper, we introduce a new statistical technique for the analysis and synthesis of small three-dimensional facial features, such as wrinkles and pores. We acquire high-resolution face geometry for people across ...

  10. Application of Detailed Chemical Kinetics to Combustion Instability Modeling

    Science.gov (United States)

    2016-01-04

    Clearance Number 15692 Clearance Date 12/3/2015 14. ABSTRACT A comparison of a single step global reaction and the detailed GRI -Mech 1.2 for combustion...comparison of a single step global reaction and the detailed GRI -Mech 1.2 for com- bustion instability modeling in a methane-fueled longitudinal-mode...methane as the fuel. We use the GRI -Mech 1.2 kinetics mechanism for methane oxidation.11 The GRI -Mech 1.2 was chosen over 2.11 because the only

  11. Beyond Standard Model Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bellantoni, L.

    2009-11-01

    There are many recent results from searches for fundamental new physics using the TeVatron, the SLAC b-factory and HERA. This talk quickly reviewed searches for pair-produced stop, for gauge-mediated SUSY breaking, for Higgs bosons in the MSSM and NMSSM models, for leptoquarks, and v-hadrons. There is a SUSY model which accommodates the recent astrophysical experimental results that suggest that dark matter annihilation is occurring in the center of our galaxy, and a relevant experimental result. Finally, model-independent searches at D0, CDF, and H1 are discussed.

  12. Formulation of probabilistic models of protein structure in atomic detail using the reference ratio method

    DEFF Research Database (Denmark)

    Valentin, Jan B.; Andreetta, Christian; Boomsma, Wouter

    2014-01-01

    We propose a method to formulate probabilistic models of protein structure in atomic detail, for a given amino acid sequence, based on Bayesian principles, while retaining a close link to physics. We start from two previously developed probabilistic models of protein structure on a local length s....... The results indicate that the proposed method and the probabilistic models show considerable promise for probabilistic protein structure prediction and related applications. © 2013 Wiley Periodicals, Inc....

  13. Detailed kinetic modeling study of n-pentanol oxidation

    KAUST Repository

    Heufer, Karl Alexander; Sarathy, Mani; Curran, Henry J.; Davis, Alexander C.; Westbrook, Charles K.; Pitz, William J.

    2012-01-01

    To help overcome the world's dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailed kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C-H and C-C bond dissociation energies. The proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes. © 2012 American Chemical Society.

  14. Detailed kinetic modeling study of n-pentanol oxidation

    KAUST Repository

    Heufer, Karl Alexander

    2012-10-18

    To help overcome the world\\'s dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailed kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C-H and C-C bond dissociation energies. The proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes. © 2012 American Chemical Society.

  15. Legacy tree data: A national database of detailed tree measurements for volume, weight, and physical properties

    Science.gov (United States)

    P.J. Radtke; D.M. Walker; A.R. Weiskittel; J. Frank; J.W. Coulston; J.A. Westfall

    2015-01-01

    Forest mensurationists in the United States have expended considerable effort over the past century making detailed observations of trees’ dimensions. In recent decades efforts have focused increasingly on weights and physical properties. Work is underway to compile original measurements from past volume, taper, and weight or biomass studies for North American tree...

  16. Development of the physical model

    International Nuclear Information System (INIS)

    Liu Zunqi; Morsy, Samir

    2001-01-01

    Full text: The Physical Model was developed during Program 93+2 as a technical tool to aid enhanced information analysis and now is an integrated part of the Department's on-going State evaluation process. This paper will describe the concept of the Physical Model, including its objectives, overall structure and the development of indicators with designated strengths, followed by a brief description of using the Physical Model in implementing the enhanced information analysis. The work plan for expansion and update of the Physical Model is also presented at the end of the paper. The development of the Physical Model is an attempt to identify, describe and characterize every known process for carrying out each step necessary for the acquisition of weapons-usable material, i.e., all plausible acquisition paths for highly enriched uranium (HEU) and separated plutonium (Pu). The overall structure of the Physical Model has a multilevel arrangement. It includes at the top level all the main steps (technologies) that may be involved in the nuclear fuel cycle from the source material production up to the acquisition of weapons-usable material, and then beyond the civilian fuel cycle to the development of nuclear explosive devices (weaponization). Each step is logically interconnected with the preceding and/or succeeding steps by nuclear material flows. It contains at its lower levels every known process that is associated with the fuel cycle activities presented at the top level. For example, uranium enrichment is broken down into three branches at the second level, i.e., enrichment of UF 6 , UCl 4 and U-metal respectively; and then further broken down at the third level into nine processes: gaseous diffusion, gas centrifuge, aerodynamic, electromagnetic, molecular laser (MLIS), atomic vapor laser (AVLIS), chemical exchange, ion exchange and plasma. Narratives are presented at each level, beginning with a general process description then proceeding with detailed

  17. Detailed modeling of hydrocarbon nanoparticle nucleation in acetylene discharges

    International Nuclear Information System (INIS)

    Bleecker, Kathleen de; Bogaerts, Annemie; Goedheer, Wim

    2006-01-01

    The initial stage of nanoparticle formation and growth in radiofrequency acetylene (C 2 H 2 ) plasmas is investigated by means of a self-consistent one-dimensional fluid model. A detailed chemical kinetic scheme, containing electron impact, ion-neutral, and neutral-neutral reactions, has been developed in order to predict the underlying dust growth mechanisms and the most important dust precursors. The model considers 41 different species (neutrals, radicals, ions, and electrons) describing hydrocarbons (C n H m ) containing up to 12 carbon atoms. Possible routes for particle growth are discussed. Both positive and negative ion reaction pathways are considered, as consecutive anion- and cation-molecule reactions seem to lead to a fast build up of the carbon skeleton

  18. Exploring new models in all detail with SARAH

    CERN Document Server

    Staub, Florian

    2015-01-01

    I give an overview about the features the Mathematica package SARAH provides to study new models. In general, SARAH can handle a wide range of models beyond the MSSM coming with additional chiral superfields, extra gauge groups, or distinctive features like Dirac gaugino masses. All of these models can be implemented in a compact form in SARAH and are easy to use: SARAH extracts all analytical properties of the given model like two-loop renormalization group equations, tadpole equations, mass matrices and vertices. Also one- and two-loop corrections to tadpoles and self-energies can be obtained. For numerical calculations SARAH can be interfaced to other tools to get the mass spectrum, to check flavour or dark matter constraints, and to test the vacuum stability, or to perform collider studies. In particular, the interface to SPheno allows a precise prediction of the Higgs mass in a given model comparable to MSSM precision by incorporating the important two-loop corrections. I show in great detail at the exam...

  19. Real-time Deformation of Detailed Geometry Based on Mappings to a Less Detailed Physical Simulation on the GPU

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    Modern graphics processing units (GPUs) can be effectively used to solve physical systems. To use the GPUoptimally, the discretization of the physical system is often restricted to a regular grid. When grid values representspatial positions, a direct visualization can result in a jagged appearance....... In this paper we propose todecouple computation and visualization of such systems. We define mappings that enable the deformation of ahigh-resolution surface based on a physical simulation on a lower resolution uniform grid. More specifically weinvestigate new approaches for the visualization of a GPU based...

  20. The impact of model detail on power grid resilience measures

    Science.gov (United States)

    Auer, S.; Kleis, K.; Schultz, P.; Kurths, J.; Hellmann, F.

    2016-05-01

    Extreme events are a challenge to natural as well as man-made systems. For critical infrastructure like power grids, we need to understand their resilience against large disturbances. Recently, new measures of the resilience of dynamical systems have been developed in the complex system literature. Basin stability and survivability respectively assess the asymptotic and transient behavior of a system when subjected to arbitrary, localized but large perturbations in frequency and phase. To employ these methods that assess power grid resilience, we need to choose a certain model detail of the power grid. For the grid topology we considered the Scandinavian grid and an ensemble of power grids generated with a random growth model. So far the most popular model that has been studied is the classical swing equation model for the frequency response of generators and motors. In this paper we study a more sophisticated model of synchronous machines that also takes voltage dynamics into account, and compare it to the previously studied model. This model has been found to give an accurate picture of the long term evolution of synchronous machines in the engineering literature for post fault studies. We find evidence that some stable fix points of the swing equation become unstable when we add voltage dynamics. If this occurs the asymptotic behavior of the system can be dramatically altered, and basin stability estimates obtained with the swing equation can be dramatically wrong. We also find that the survivability does not change significantly when taking the voltage dynamics into account. Further, the limit cycle type asymptotic behaviour is strongly correlated with transient voltages that violate typical operational voltage bounds. Thus, transient voltage bounds are dominated by transient frequency bounds and play no large role for realistic parameters.

  1. Detailed model for practical pulverized coal furnaces and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Smoot, L.D.

    1989-08-01

    This study has been supported by a consortium of nine industrial and governmental sponsors. Work was initiated on May 1, 1985 and completed August 31, 1989. The central objective of this work was to develop, evaluate and apply a practical combustion model for utility boilers, industrial furnaces and gasifiers. Key accomplishments have included: Development of an advanced first-generation, computer model for combustion in three dimensional furnaces; development of a new first generation fouling and slagging submodel; detailed evaluation of an existing NO{sub x} submodel; development and evaluation of an improved radiation submodel; preparation and distribution of a three-volume final report: (a) Volume 1: General Technical Report; (b) Volume 2: PCGC-3 User's Manual; (c) Volume 3: Data Book for Evaluation of Three-Dimensional Combustion Models; and organization of a user's workshop on the three-dimensional code. The furnace computer model developed under this study requires further development before it can be applied generally to all applications; however, it can be used now by specialists for many specific applications, including non-combusting systems and combusting geseous systems. A new combustion center was organized and work was initiated to continue the important research effort initiated by this study. 212 refs., 72 figs., 38 tabs.

  2. Urban scale air quality modelling using detailed traffic emissions estimates

    Science.gov (United States)

    Borrego, C.; Amorim, J. H.; Tchepel, O.; Dias, D.; Rafael, S.; Sá, E.; Pimentel, C.; Fontes, T.; Fernandes, P.; Pereira, S. R.; Bandeira, J. M.; Coelho, M. C.

    2016-04-01

    The atmospheric dispersion of NOx and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale.

  3. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.

    2005-01-01

    Temperature-programmed desorption (TPD) of CO has been performed on supported and unsupported nickel catalysts. The unsupported Ni catalyst consists of a Ni(14 13 13) single crystal which has been studied under ultrahigh vacuum conditions. The desorption energy for CO at low CO surface coverage...... was found to be 119 kJ/mol, and the binding energy of C to the Ni(111) surface of the crystal was 703 kJ/mol. The supported catalysts consist of nickel supported on hydrotalcite-like compounds with three different Mg2+/Al3+ ratios. The experimental results show that for the supported Ni catalysts TPD of CO...... precursor seems to result in more steplike sites, kinks, and defects for carbon monoxide dissociation. A detailed kinetic modeling of the TPO results based on elementary reaction steps has been conducted to give an energetic map of supported Ni catalysts. Experimental results from the ideal Ni surface fit...

  4. Detailed analysis of the scope of the modified Firsov model

    International Nuclear Information System (INIS)

    Cruz, S.A.; Vargas-Aburto, C.; Brice, D.K.; Alonso, E.V.; Armour, D.G.

    1983-01-01

    A detailed and systematic analysis of the scope of the Firsov model as modified by Cheshire when no adjustable parameters are included in the calculations of the low-velocity electronic-stopping cross section is presented. For this purpose we summarize and extend our previously reported [Radiat. Eff. Lett. 43, 79 (1979); Nucl. Instrum. Methods 170, 205 (1980)] preliminary results on the role of all computational degrees of freedom that influence the outcome of the calculations, namely, (a) inclusion of trajectory, (b) accuracy of wave functions and speed of atomic electrons, (c) motion of Firsov's plane, and (d) consideration of experimental conditions. We find that the Firsov theory is accurate only within a factor of 2; therefore, at least a scale factor is necessary in order to get reasonable agreement with experiment

  5. Utilization of Large Scale Surface Models for Detailed Visibility Analyses

    Science.gov (United States)

    Caha, J.; Kačmařík, M.

    2017-11-01

    This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

  6. On the physical and chemical details of alumina atomic layer deposition: A combined experimental and numerical approach

    International Nuclear Information System (INIS)

    Pan, Dongqing; Ma, Lulu; Xie, Yuanyuan; Yuan, Chris; Jen, Tien Chien

    2015-01-01

    Alumina thin film is typically studied as a model atomic layer deposition (ALD) process due to its high dielectric constant, high thermal stability, and good adhesion on various wafer surfaces. Despite extensive applications of alumina ALD in microelectronics industries, details on the physical and chemical processes are not yet well understood. ALD experiments are not able to shed adequate light on the detailed information regarding the transient ALD process. Most of current numerical approaches lack detailed surface reaction mechanisms, and their results are not well correlated with experimental observations. In this paper, the authors present a combined experimental and numerical study on the details of flow and surface reactions in alumina ALD using trimethylaluminum and water as precursors. Results obtained from experiments and simulations are compared and correlated. By experiments, growth rate on five samples under different deposition conditions is characterized. The deposition rate from numerical simulation agrees well with the experimental results. Details of precursor distributions in a full cycle of ALD are studied numerically to bridge between experimental observations and simulations. The 3D transient numerical model adopts surface reaction kinetics and mechanisms based on atomic-level studies to investigate the surface deposition process. Surface deposition is shown as a strictly self-limited process in our numerical studies. ALD is a complex strong-coupled fluid, thermal and chemical process, which is not only heavily dependent on the chemical kinetics and surface conditions but also on the flow and material distributions

  7. Detailed model for practical pulverized coal furnaces and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Philips, S.D.; Smoot, L.D.

    1989-08-01

    The need to improve efficiency and reduce pollutant emissions commercial furnaces has prompted energy companies to search for optimized operating conditions and improved designs in their fossil-fuel burning facilities. Historically, companies have relied on the use of empirical correlations and pilot-plant data to make decisions about operating conditions and design changes. The high cost of collecting data makes obtaining large amounts of data infeasible. The main objective of the data book is to provide a single source of detailed three-dimensional combustion and combustion-related data suitable for comprehensive combustion model evaluation. Five tasks were identified as requirements to achieve the main objective. First, identify the types of data needed to evaluate comprehensive combustion models, and establish criteria for selecting the data. Second, identify and document available three-dimensional combustion data related to pulverized coal combustion. Third, collect and evaluate three-dimensional data cases, and select suitable cases based on selection criteria. Fourth, organize the data sets into an easy-to-use format. Fifth, evaluate and interpret the nature and quality of the data base. 39 refs., 15 figs., 14 tabs.

  8. Trajectory control sensor engineering model detailed test objective

    Science.gov (United States)

    Dekome, Kent; Barr, Joseph Martin

    1991-01-01

    The concept employed in an existing Trajectory Control Sensor (TCS) breadboard is being developed into an engineering model to be considered for flight on the Shuttle as a Detailed Test Objective (DTO). The sensor design addresses the needs of Shuttle/SSF docking/berthing by providing relative range and range rate to 1500 meters as well as the perceived needs of AR&C by relative attitude measurement over the last 100 meters. Range measurement is determined using a four-tone ranging technique. The Doppler shift on the highest frequency tone will be used to provide direct measurement of range rate. Bearing rate and attitude rates will be determined through back differencing of bearing and attitude, respectively. The target consists of an isosceles triangle configuration of three optical retroreflectors, roughly one meter and one-half meter in size. After target acquisition, the sensor continually updates the positions of the three retros at a rate of about one hertz. The engineering model is expected to weigh about 25 pounds, consume 25-30 watts, and have an envelope of about 1.25 cubic feet. The following concerns were addressed during the presentation: are there any concerns with differentiating attitude and bearing to get attitude and bearing rates? Since the docking scenario has low data bandwidth, back differencing is a sufficient approximation of a perfect differentiator for this application. Could range data be obtained if there were no retroreflectors on the target vehicle? Possibly, but only at close range. It would be dependent on target characteristics.

  9. Detailed modelling of strong ground motion in Trieste

    International Nuclear Information System (INIS)

    Vaccari, F.; Romanelli, F.; Panza, G.

    2005-05-01

    Trieste has been included in category IV by the new Italian seismic code. This corresponds to a horizontal acceleration of 0.05g for the anchoring of the elastic response spectrum. A detailed modelling of the ground motion in Trieste has been done for some scenario earthquakes, compatible with the seismotectonic regime of the region. Three-component synthetic seismograms (displacements, velocities and accelerations) have been analyzed to obtain significant parameters of engineering interest. The definition of the seismic input, derived from a comprehensive set of seismograms analyzed in the time and frequency domains, represents a powerful and convenient tool for seismic microzoning. In the specific case of Palazzo Carciotti, depending on the azimuth of the incoming wavefield, an increase of one degree in intensity may be expected due to different amplification patterns, while a nice stability can be seen in the periods corresponding to the peak values, with amplifications around 1 and 2 Hz. For Palazzo Carciotti, the most dangerous scenario considered, for an event of M=6.5 at an epicentral distance of 21 km, modelled taking into account source finiteness and directivity, leads to a peak ground acceleration value of 0.2 g. The seismic code, being based on a probabilistic approach, can be considered representative of the average seismic shaking for the province of Trieste, and can slightly underestimate the seismic input due the seismogenic potential (obtained from the historical seismicity and seismotectonics). Furthermore, relevant local site effects are mostly neglected. Both modelling and observations show that site conditions in the centre of Trieste can amplify the ground motion at the bedrock by a factor of five, in the frequency range of engineering interest. We may therefore expect macroseismic intensities as high as IX (MCS) corresponding to VIII (MSK). Spectral amplifications obtained for the considered scenario earthquakes are strongly event

  10. A New, Two-layer Canopy Module For The Detailed Snow Model SNOWPACK

    Science.gov (United States)

    Gouttevin, I.; Lehning, M.; Jonas, T.; Gustafsson, D.; Mölder, M.

    2014-12-01

    A new, two-layer canopy module with thermal inertia for the detailed snow model SNOWPACK is presented. Compared to the old, one-layered canopy formulation with no heat mass, this module now offers a level of physical detail consistent with the detailed snow and soil representation in SNOWPACK. The new canopy model is designed to reproduce the difference in thermal regimes between leafy and woody canopy elements and their impact on the underlying snowpack energy balance. The new model is validated against data from an Alpine and a boreal site. Comparisons of modelled sub-canopy thermal radiations to stand-scale observations at Alptal, Switzerland, demonstrate the improvements induced by our new parameterizations. The main effect is a more realistic simulation of the canopy night-time drop in temperatures. The lower drop is induced by both thermal inertia and the two-layer representation. A specific result is that such a performance cannot be achieved by a single-layered canopy model. The impact of the new parameterizations on the modelled dynamics of the sub-canopy snowpack is analysed and yields consistent results, but the frequent occurrence of mixed-precipitation events at Alptal prevents a conclusive assessment of model performances against snow data.Without specific tuning, the model is also able to reproduce the measured summertime tree trunk temperatures and biomass heat storage at the boreal site of Norunda, Sweden, with an increased accuracy in amplitude and phase. Overall, the SNOWPACK model with its enhanced canopy module constitutes a unique (in its physical process representation) atmosphere-to-soil-through-canopy-and-snow modelling chain.

  11. Formulation of probabilistic models of protein structure in atomic detail using the reference ratio method.

    Science.gov (United States)

    Valentin, Jan B; Andreetta, Christian; Boomsma, Wouter; Bottaro, Sandro; Ferkinghoff-Borg, Jesper; Frellsen, Jes; Mardia, Kanti V; Tian, Pengfei; Hamelryck, Thomas

    2014-02-01

    We propose a method to formulate probabilistic models of protein structure in atomic detail, for a given amino acid sequence, based on Bayesian principles, while retaining a close link to physics. We start from two previously developed probabilistic models of protein structure on a local length scale, which concern the dihedral angles in main chain and side chains, respectively. Conceptually, this constitutes a probabilistic and continuous alternative to the use of discrete fragment and rotamer libraries. The local model is combined with a nonlocal model that involves a small number of energy terms according to a physical force field, and some information on the overall secondary structure content. In this initial study we focus on the formulation of the joint model and the evaluation of the use of an energy vector as a descriptor of a protein's nonlocal structure; hence, we derive the parameters of the nonlocal model from the native structure without loss of generality. The local and nonlocal models are combined using the reference ratio method, which is a well-justified probabilistic construction. For evaluation, we use the resulting joint models to predict the structure of four proteins. The results indicate that the proposed method and the probabilistic models show considerable promise for probabilistic protein structure prediction and related applications. Copyright © 2013 Wiley Periodicals, Inc.

  12. Boosting flood warning schemes with fast emulator of detailed hydrodynamic models

    Science.gov (United States)

    Bellos, V.; Carbajal, J. P.; Leitao, J. P.

    2017-12-01

    Floods are among the most destructive catastrophic events and their frequency has incremented over the last decades. To reduce flood impact and risks, flood warning schemes are installed in flood prone areas. Frequently, these schemes are based on numerical models which quickly provide predictions of water levels and other relevant observables. However, the high complexity of flood wave propagation in the real world and the need of accurate predictions in urban environments or in floodplains hinders the use of detailed simulators. This sets the difficulty, we need fast predictions that meet the accuracy requirements. Most physics based detailed simulators although accurate, will not fulfill the speed demand. Even if High Performance Computing techniques are used (the magnitude of required simulation time is minutes/hours). As a consequence, most flood warning schemes are based in coarse ad-hoc approximations that cannot take advantage a detailed hydrodynamic simulation. In this work, we present a methodology for developing a flood warning scheme using an Gaussian Processes based emulator of a detailed hydrodynamic model. The methodology consists of two main stages: 1) offline stage to build the emulator; 2) online stage using the emulator to predict and generate warnings. The offline stage consists of the following steps: a) definition of the critical sites of the area under study, and the specification of the observables to predict at those sites, e.g. water depth, flow velocity, etc.; b) generation of a detailed simulation dataset to train the emulator; c) calibration of the required parameters (if measurements are available). The online stage is carried on using the emulator to predict the relevant observables quickly, and the detailed simulator is used in parallel to verify key predictions of the emulator. The speed gain given by the emulator allows also to quantify uncertainty in predictions using ensemble methods. The above methodology is applied in real

  13. Looking for physics beyond the standard model

    International Nuclear Information System (INIS)

    Binetruy, P.

    2002-01-01

    Motivations for new physics beyond the Standard Model are presented. The most successful and best motivated option, supersymmetry, is described in some detail, and the associated searches performed at LEP are reviewed. These include searches for additional Higgs bosons and for supersymmetric partners of the standard particles. These searches constrain the mass of the lightest supersymmetric particle which could be responsible for the dark matter of the universe. (authors)

  14. Physical models for high burnup fuel

    International Nuclear Information System (INIS)

    Kanyukova, V.; Khoruzhii, O.; Likhanskii, V.; Solodovnikov, G.; Sorokin, A.

    2003-01-01

    In this paper some models of processes in high burnup fuel developed in Src of Russia Troitsk Institute for Innovation and Fusion Research are presented. The emphasis is on the description of the degradation of the fuel heat conductivity, radial profiles of the burnup and the plutonium accumulation, restructuring of the pellet rim, mechanical pellet-cladding interaction. The results demonstrate the possibility of rather accurate description of the behaviour of the fuel of high burnup on the base of simplified models in frame of the fuel performance code if the models are physically ground. The development of such models requires the performance of the detailed physical analysis to serve as a test for a correct choice of allowable simplifications. This approach was applied in the SRC of Russia TRINITI to develop a set of models for the WWER fuel resulting in high reliability of predictions in simulation of the high burnup fuel

  15. Physical Modeling Modular Boxes: PHOXES

    DEFF Research Database (Denmark)

    Gelineck, Steven; Serafin, Stefania

    2010-01-01

    This paper presents the development of a set of musical instruments, which are based on known physical modeling sound synthesis techniques. The instruments are modular, meaning that they can be combined in various ways. This makes it possible to experiment with physical interaction and sonic...

  16. Comparing Epileptiform Behavior of Mesoscale Detailed Models and Population Models of Neocortex

    NARCIS (Netherlands)

    Visser, S.; Meijer, Hil Gaétan Ellart; Lee, Hyong C.; van Drongelen, Wim; van Putten, Michel Johannes Antonius Maria; van Gils, Stephanus A.

    2010-01-01

    Two models of the neocortex are developed to study normal and pathologic neuronal activity. One model contains a detailed description of a neocortical microcolumn represented by 656 neurons, including superficial and deep pyramidal cells, four types of inhibitory neurons, and realistic synaptic

  17. Standard Model physics

    CERN Multimedia

    Altarelli, Guido

    1999-01-01

    Introduction structure of gauge theories. The QEDand QCD examples. Chiral theories. The electroweak theory. Spontaneous symmetry breaking. The Higgs mechanism Gauge boson and fermion masses. Yukawa coupling. Charges current couplings. The Cabibo-Kobayashi-Maskawa matrix and CP violation. Neutral current couplings. The Glasow-Iliopoulos-Maiani mechanism. Gauge boson and Higgs coupling. Radiative corrections and loops. Cancellation of the chiral anomaly. Limits on the Higgs comparaison. Problems of the Standard Model. Outlook.

  18. Detailed modeling of common rail fuel injection process

    NARCIS (Netherlands)

    Seykens, X.L.J.; Somers, L.M.T.; Baert, R.S.G.

    2005-01-01

    Modeling of fuel injection equipment is a tool that is used increasingly for explaining or predicting the effect of advanced diesel injection strategies on combustion and emissions. This paper reports on the modeling of the high-pressure part of a research type Heavy Duty Common Rail (CR) fuel

  19. Detailed modelling of biomass pyrolysis: biomass structure and composition

    International Nuclear Information System (INIS)

    Hugony, F.; Migliavacca, G.; Faravelli, T.; Ranzi, E.

    2007-01-01

    The research routes followed in the field of numerical modelling development for biomass devolatilization are here summarised. In this first paper a wide introduction concerning the description of the chemical nature of the main classes of compounds which constitute biomasses is reported, it is the starting point for the subsequent description of the developed models, described in the companion paper [it

  20. How to Decide on Modeling Details: Risk and Benefit Assessment.

    Science.gov (United States)

    Özilgen, Mustafa

    Mathematical models based on thermodynamic, kinetic, heat, and mass transfer analysis are central to this chapter. Microbial growth, death, enzyme inactivation models, and the modeling of material properties, including those pertinent to conduction and convection heating, mass transfer, such as diffusion and convective mass transfer, and thermodynamic properties, such as specific heat, enthalpy, and Gibbs free energy of formation and specific chemical exergy are also needed in this task. The origins, simplifying assumptions, and uses of model equations are discussed in this chapter, together with their benefits. The simplified forms of these models are sometimes referred to as "laws," such as "the first law of thermodynamics" or "Fick's second law." Starting to modeling a study with such "laws" without considering the conditions under which they are valid runs the risk of ending up with erronous conclusions. On the other hand, models started with fundamental concepts and simplified with appropriate considerations may offer explanations for the phenomena which may not be obtained just with measurements or unprocessed experimental data. The discussion presented here is strengthened with case studies and references to the literature.

  1. Quasi standard model physics

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1986-01-01

    Possible small extensions of the standard model are considered, which are motivated by the strong CP problem and by the baryon asymmetry of the Universe. Phenomenological arguments are given which suggest that imposing a PQ symmetry to solve the strong CP problem is only tenable if the scale of the PQ breakdown is much above M W . Furthermore, an attempt is made to connect the scale of the PQ breakdown to that of the breakdown of lepton number. It is argued that in these theories the same intermediate scale may be responsible for the baryon number of the Universe, provided the Kuzmin Rubakov Shaposhnikov (B+L) erasing mechanism is operative. (orig.)

  2. Toward a detailed computational model for the mammalian circadian clock

    Science.gov (United States)

    Leloup, Jean-Christophe; Goldbeter, Albert

    2003-06-01

    We present a computational model for the mammalian circadian clock based on the intertwined positive and negative regulatory loops involving the Per, Cry, Bmal1, Clock, and Rev-Erb genes. In agreement with experimental observations, the model can give rise to sustained circadian oscillations in continuous darkness, characterized by an antiphase relationship between Per/Cry/Rev-Erb and Bmal1 mRNAs. Sustained oscillations correspond to the rhythms autonomously generated by suprachiasmatic nuclei. For other parameter values, damped oscillations can also be obtained in the model. These oscillations, which transform into sustained oscillations when coupled to a periodic signal, correspond to rhythms produced by peripheral tissues. When incorporating the light-induced expression of the Per gene, the model accounts for entrainment of the oscillations by light-dark cycles. Simulations show that the phase of the oscillations can then vary by several hours with relatively minor changes in parameter values. Such a lability of the phase could account for physiological disorders related to circadian rhythms in humans, such as advanced or delayed sleep phase syndrome, whereas the lack of entrainment by light-dark cycles can be related to the non-24h sleep-wake syndrome. The model uncovers the possible existence of multiple sources of oscillatory behavior. Thus, in conditions where the indirect negative autoregulation of Per and Cry expression is inoperative, the model indicates the possibility that sustained oscillations might still arise from the negative autoregulation of Bmal1 expression.

  3. Detailed Modelling of Kinetic Biodegradation Processes in a Laboratory Mmicrocosm

    Science.gov (United States)

    Watson, I.; Oswald, S.; Banwart, S.; Mayer, U.

    2003-04-01

    Biodegradation of organic contaminants in soil and groundwater usually takes places via different redox processes happening sequentially as well as simultaneously. We used numerical modelling of a long-term lab microcosm experiment to simulate the dynamic behaviour of fermentation and respiration in the aqueous phase in contact with the sandstone material, and to develop a conceptual model describing these processes. Aqueous speciation, surface complexation, mineral dissolution and precipitation were taken into account also. Fermentation can be the first step of the degradation process producing intermediate species, which are subsequently consumed by TEAPs. Microbial growth and substrate utilisation kinetics are coupled via a formulation that also includes aqueous speciation and other geochemical reactions including surface complexation, mineral dissolution and precipitation. Competitive exclusion between TEAPs is integral to the conceptual model of the simulation, and the results indicate that exclusion is not complete, but some overlap is found between TEAPs. The model was used to test approaches like the partial equilibrium approach that currently make use of hydrogen levels to diagnose prevalent TEAPs in groundwater. The observed pattern of hydrogen and acetate concentrations were reproduced well by the simulations, and the results show the relevance of kinetics, lag times and inhibition, and especially that intermediate products play a key role.

  4. Inner life of elementary particles. Pt. V. Detail model

    International Nuclear Information System (INIS)

    Geitner, Uwe W.

    2011-01-01

    The author tries to develop a model for the cosmological beginning of the universe starting from the existing world. The booklet (part IV) includes the following chapters: introduction; origin of vibrations; origin of the big-bang; origin of elementary particles; charges and fields, unified conception of forces; conclusions.

  5. Detailed modelling of a flue-gas desulfurisation plant

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, A.; Fueyo, N.; Tomas, A. [University of Zaragoza, Zaragoza (Spain)

    2007-11-15

    This paper presents a CFD model for a flue-gas desulfurisation plant, and its application to an operating plant. The FGD plant is of the wet-scrubber type, with co-current and counter-current sections. The sorbent used is limestone, and, after cleaning the flue gases, the limestone slurry is collected in an oxidation tank for the production of gypsum. The model uses an Eulerian-Eulerian treatment of the multiphase flow in the absorber and the tank. The essential mass-transfer mechanisms (such as SO{sub 2} and O{sub 2} absorption and CO{sub 2} desorption) are accounted for, as are also the main chemical kinetics leading to the formation of gypsum. Given the different nature of the flow in the absorber and tank, two separate simulations are conducted for each of these domains, and the solutions are iteratively coupled through boundary conditions during the calculations. The model is applied to the FGD plant of the Teruel powerstation located in Andorra (Teruel, Spain). The powerstation is fired with a high-sulfur coal (up to 4.5 percent), and the FGD system has been designed for a desulfurisation capacity of 1.4 million N m{sup 3}/hr for a desulfurisation efficiency in excess of 90 percent. Validation of the model is conducted by comparison with available plant data for two design coals and two desulfurisation efficiencies. The model accuracy is reasonable, given the complexity of the aero/hydrodynamical and thermo-chemical phenomena involved.

  6. Detailed modeling of the statistical uncertainty of Thomson scattering measurements

    International Nuclear Information System (INIS)

    Morton, L A; Parke, E; Hartog, D J Den

    2013-01-01

    The uncertainty of electron density and temperature fluctuation measurements is determined by statistical uncertainty introduced by multiple noise sources. In order to quantify these uncertainties precisely, a simple but comprehensive model was made of the noise sources in the MST Thomson scattering system and of the resulting variance in the integrated scattered signals. The model agrees well with experimental and simulated results. The signal uncertainties are then used by our existing Bayesian analysis routine to find the most likely electron temperature and density, with confidence intervals. In the model, photonic noise from scattered light and plasma background light is multiplied by the noise enhancement factor (F) of the avalanche photodiode (APD). Electronic noise from the amplifier and digitizer is added. The amplifier response function shapes the signal and induces correlation in the noise. The data analysis routine fits a characteristic pulse to the digitized signals from the amplifier, giving the integrated scattered signals. A finite digitization rate loses information and can cause numerical integration error. We find a formula for the variance of the scattered signals in terms of the background and pulse amplitudes, and three calibration constants. The constants are measured easily under operating conditions, resulting in accurate estimation of the scattered signals' uncertainty. We measure F ≈ 3 for our APDs, in agreement with other measurements for similar APDs. This value is wavelength-independent, simplifying analysis. The correlated noise we observe is reproduced well using a Gaussian response function. Numerical integration error can be made negligible by using an interpolated characteristic pulse, allowing digitization rates as low as the detector bandwidth. The effect of background noise is also determined

  7. Black liquor devolatilization and swelling - a detailed droplet model and experimental validation

    International Nuclear Information System (INIS)

    Jaervinen, M.; Zevenhoven, R.; Vakkilainen, E.; Forssen, M.

    2003-01-01

    In this paper, we present results from a new detailed physical model for single black liquor droplet pyrolysis and swelling, and validate them against experimental data from a non-oxidizing environment using two different reactor configurations. In the detailed model, we solve for the heat transfer and gas phase mass transfer in the droplet and thereby, the intra-particle gas-char and gas-gas interactions during drying and devolatilization can be studied. In the experimental part, the mass change, the swelling behaviour, and the volume fraction of larger voids, i.e. cenospheres in the droplets were determined in a non-oxidizing environment. The model gave a good correlation with experimental swelling and mass loss data. Calculations suggest that a considerable amount of the char can be consumed before the entire droplet has experienced the devolatilization and drying stages of combustion. Char formed at the droplet surface layer is generally consumed by gasification with H 2 O flowing outwards from the droplet interior. The extent of char conversion during devolatilization and the rate of devolatilization are greatly affected by swelling and the formation of larger voids in the particle. The more the particle swells and the more homogeneous the particle structure is, the larger is the conversion of char at the end of devolatilization

  8. Impact of a highly detailed emission inventory on modeling accuracy

    Science.gov (United States)

    Taghavi, M.; Cautenet, S.; Arteta, J.

    2005-03-01

    During Expérience sur Site pour COntraindre les Modèles de Pollution atmosphérique et de Transport d'Emissions (ESCOMPTE) campaign (June 10 to July 14, 2001), two pollution events observed during an intensive measurement period (IOP2a and IOP2b) have been simulated. The comprehensive Regional Atmospheric Modeling Systems (RAMS) model, version 4.3, coupled online with a chemical module including 29 species is used to follow the chemistry of a polluted zone over Southern France. This online method takes advantage of a parallel code and use of the powerful computer SGI 3800. Runs are performed with two emission inventories: the Emission Pre Inventory (EPI) and the Main Emission Inventory (MEI). The latter is more recent and has a high resolution. The redistribution of simulated chemical species (ozone and nitrogen oxides) is compared with aircraft and surface station measurements for both runs at regional scale. We show that the MEI inventory is more efficient than the EPI in retrieving the redistribution of chemical species in space (three-dimensional) and time. In surface stations, MEI is superior especially for primary species, like nitrogen oxides. The ozone pollution peaks obtained from an inventory, such as EPI, have a large uncertainty. To understand the realistic geographical distribution of pollutants and to obtain a good order of magnitude in ozone concentration (in space and time), a high-resolution inventory like MEI is necessary. Coupling RAMS-Chemistry with MEI provides a very efficient tool able to simulate pollution plumes even in a region with complex circulations, such as the ESCOMPTE zone.

  9. Physical model of Nernst element

    International Nuclear Information System (INIS)

    Nakamura, Hiroaki; Ikeda, Kazuaki; Yamaguchi, Satarou

    1998-08-01

    Generation of electric power by the Nernst effect is a new application of a semiconductor. A key point of this proposal is to find materials with a high thermomagnetic figure-of-merit, which are called Nernst elements. In order to find candidates of the Nernst element, a physical model to describe its transport phenomena is needed. As the first model, we began with a parabolic two-band model in classical statistics. According to this model, we selected InSb as candidates of the Nernst element and measured their transport coefficients in magnetic fields up to 4 Tesla within a temperature region from 270 K to 330 K. In this region, we calculated transport coefficients numerically by our physical model. For InSb, experimental data are coincident with theoretical values in strong magnetic field. (author)

  10. Detailed Modeling and Evaluation of a Scalable Multilevel Checkpointing System

    Energy Technology Data Exchange (ETDEWEB)

    Mohror, Kathryn [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moody, Adam [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bronevetsky, Greg [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); de Supinski, Bronis R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-01

    High-performance computing (HPC) systems are growing more powerful by utilizing more components. As the system mean time before failure correspondingly drops, applications must checkpoint frequently to make progress. But, at scale, the cost of checkpointing becomes prohibitive. A solution to this problem is multilevel checkpointing, which employs multiple types of checkpoints in a single run. Moreover, lightweight checkpoints can handle the most common failure modes, while more expensive checkpoints can handle severe failures. We designed a multilevel checkpointing library, the Scalable Checkpoint/Restart (SCR) library, that writes lightweight checkpoints to node-local storage in addition to the parallel file system. We present probabilistic Markov models of SCR's performance. We show that on future large-scale systems, SCR can lead to a gain in machine efficiency of up to 35 percent, and reduce the load on the parallel file system by a factor of two. In addition, we predict that checkpoint scavenging, or only writing checkpoints to the parallel file system on application termination, can reduce the load on the parallel file system by 20 × on today's systems and still maintain high application efficiency.

  11. Automatic generation of medium-detailed 3D models of buildings based on CAD data

    NARCIS (Netherlands)

    Dominguez-Martin, B.; Van Oosterom, P.; Feito-Higueruela, F.R.; Garcia-Fernandez, A.L.; Ogayar-Anguita, C.J.

    2015-01-01

    We present the preliminary results of a work in progress which aims to obtain a software system able to automatically generate a set of diverse 3D building models with a medium level of detail, that is, more detailed that a mere parallelepiped, but not as detailed as a complete geometric

  12. Instream Physical Habitat Modelling Types

    DEFF Research Database (Denmark)

    Conallin, John; Boegh, Eva; Krogsgaard, Jørgen

    2010-01-01

    The introduction of the EU Water Framework Directive (WFD) is providing member state water resource managers with significant challenges in relation to meeting the deadline for 'Good Ecological Status' by 2015. Overall, instream physical habitat modelling approaches have advantages and disadvanta......The introduction of the EU Water Framework Directive (WFD) is providing member state water resource managers with significant challenges in relation to meeting the deadline for 'Good Ecological Status' by 2015. Overall, instream physical habitat modelling approaches have advantages...... suit their situations. This paper analyses the potential of different methods available for water managers to assess hydrological and geomorphological impacts on the habitats of stream biota, as requested by the WFD. The review considers both conventional and new advanced research-based instream...... physical habitat models. In parametric and non-parametric regression models, model assumptions are often not satisfied and the models are difficult to transfer to other regions. Research-based methods such as the artificial neural networks and individual-based modelling have promising potential as water...

  13. Development of a global computable general equilibrium model coupled with detailed energy end-use technology

    International Nuclear Information System (INIS)

    Fujimori, Shinichiro; Masui, Toshihiko; Matsuoka, Yuzuru

    2014-01-01

    Highlights: • Detailed energy end-use technology information is considered within a CGE model. • Aggregated macro results of the detailed model are similar to traditional model. • The detailed model shows unique characteristics in the household sector. - Abstract: A global computable general equilibrium (CGE) model integrating detailed energy end-use technologies is developed in this paper. The paper (1) presents how energy end-use technologies are treated within the model and (2) analyzes the characteristics of the model’s behavior. Energy service demand and end-use technologies are explicitly considered, and the share of technologies is determined by a discrete probabilistic function, namely a Logit function, to meet the energy service demand. Coupling with detailed technology information enables the CGE model to have more realistic representation in the energy consumption. The proposed model in this paper is compared with the aggregated traditional model under the same assumptions in scenarios with and without mitigation roughly consistent with the two degree climate mitigation target. Although the results of aggregated energy supply and greenhouse gas emissions are similar, there are three main differences between the aggregated and the detailed technologies models. First, GDP losses in mitigation scenarios are lower in the detailed technology model (2.8% in 2050) as compared with the aggregated model (3.2%). Second, price elasticity and autonomous energy efficiency improvement are heterogeneous across regions and sectors in the detailed technology model, whereas the traditional aggregated model generally utilizes a single value for each of these variables. Third, the magnitude of emissions reduction and factors (energy intensity and carbon factor reduction) related to climate mitigation also varies among sectors in the detailed technology model. The household sector in the detailed technology model has a relatively higher reduction for both energy

  14. Accelerator physics and modeling: Proceedings

    International Nuclear Information System (INIS)

    Parsa, Z.

    1991-01-01

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings

  15. Wave Generation in Physical Models

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Frigaard, Peter

    The present book describes the most important aspects of wave generation techniques in physical models. Moreover, the book serves as technical documentation for the wave generation software AwaSys 6, cf. Aalborg University (2012). In addition to the two main authors also Tue Hald and Michael...

  16. Evaluating nuclear physics inputs in core-collapse supernova models

    Science.gov (United States)

    Lentz, E.; Hix, W. R.; Baird, M. L.; Messer, O. E. B.; Mezzacappa, A.

    Core-collapse supernova models depend on the details of the nuclear and weak interaction physics inputs just as they depend on the details of the macroscopic physics (transport, hydrodynamics, etc.), numerical methods, and progenitors. We present preliminary results from our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions.

  17. Physical models of cell motility

    CERN Document Server

    2016-01-01

    This book surveys the most recent advances in physics-inspired cell movement models. This synergetic, cross-disciplinary effort to increase the fidelity of computational algorithms will lead to a better understanding of the complex biomechanics of cell movement, and stimulate progress in research on related active matter systems, from suspensions of bacteria and synthetic swimmers to cell tissues and cytoskeleton.Cell motility and collective motion are among the most important themes in biology and statistical physics of out-of-equilibrium systems, and crucial for morphogenesis, wound healing, and immune response in eukaryotic organisms. It is also relevant for the development of effective treatment strategies for diseases such as cancer, and for the design of bioactive surfaces for cell sorting and manipulation. Substrate-based cell motility is, however, a very complex process as regulatory pathways and physical force generation mechanisms are intertwined. To understand the interplay between adhesion, force ...

  18. Impact of Model Detail of Synchronous Machines on Real-time Transient Stability Assessment

    DEFF Research Database (Denmark)

    Weckesser, Johannes Tilman Gabriel; Jóhannsson, Hjörtur; Østergaard, Jacob

    2013-01-01

    In this paper, it is investigated how detailed the model of a synchronous machine needs to be in order to assess transient stability using a Single Machine Equivalent (SIME). The results will show how the stability mechanism and the stability assessment are affected by the model detail. In order...... of the machine models is varied. Analyses of the results suggest that a 4th-order model may be sufficient to represent synchronous machines in transient stability studies....

  19. Physical model of reactor pulse

    International Nuclear Information System (INIS)

    Petrovic, A.; Ravnik, M.

    2004-01-01

    Pulse experiments have been performed at J. Stefan Institute TRIGA reactor since 1991. In total, more than 130 pulses have been performed. Extensive experimental information on the pulse physical characteristics has been accumulated. Fuchs-Hansen adiabatic model has been used for predicting and analysing the pulse parameters. The model is based on point kinetics equation, neglecting the delayed neutrons and assuming constant inserted reactivity in form of step function. Deficiencies of the Fuchs-Hansen model and systematic experimental errors have been observed and analysed. Recently, the pulse model was improved by including the delayed neutrons and time dependence of inserted reactivity. The results explain the observed non-linearity of the pulse energy for high pulses due to finite time of pulse rod withdrawal and the contribution of the delayed neutrons after the prompt part of the pulse. The results of the improved model are in good agreement with experimental results. (author)

  20. A detailed approach to model transport, heterogeneous chemistry, and electrochemistry in solid-oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Janardhanan, V.

    2007-07-01

    This dissertation layes out detailed descriptions for heterogeneous chemistry, electrochemistry, and porous media transport models to simulate solid oxide fuel cells (SOFCs). An elementary like heterogeneous reaction mechanism for the steam reforming of CH4 developed in our research group is used throughout this work. Based on assumption of hydrogen oxidation as the only electrochemical reaction and single step electron transfer reaction as rate limiting, a modified Butler-Volmer equation is used to model the electrochemistry. The pertinence of various porous media transport models such as Modified Fick Model (MFM), Dusty Gas Model (DGM), Mean Transport Pore Model, Modified Maxwell Stefan Model, and Generalized Maxwell Stefan Model under reaction conditions are studied. In general MFM and DGM predictions are in good agreement with experimental data. Physically realistic electrochemical model parameters are very important for fuel cell modeling. Button cell simulations are carried out to deduce the electrochemical model parameters, and those parameters are further used in the modeling of planar cells. Button cell simulations are carried out using the commercial CFD code FLUENT coupled with DETCHEM. For all temperature ranges the model works well in predicting the experimental observations in the high current density region. However, the model predicts much higher open circuit potentials than that observed in the experiments, mainly due to the absence of coking model in the elementary heterogeneous mechanism leading to nonequilibrium compositions. Furthermore, the study presented here employs Nernst equation for the calculation of reversible potential which is strictly valid only for electrochemical equilibrium. It is assumed that the electrochemical charge transfer reaction involving H2 is fast enough to be in equilibrium. However, the comparison of model prediction with thermodynamic equilibrium reveals that this assumption is violated under very low current

  1. Revisiting the concept level of detail in 3D city modelling

    NARCIS (Netherlands)

    Biljecki, F.; Zhao, J.; Stoter, J.E.; Ledoux, H.

    2013-01-01

    This review paper discusses the concept of level of detail in 3D city modelling, and is a first step towards a foundation for a standardised definition. As an introduction, a few level of detail specifications, outlooks and approaches are given from the industry. The paper analyses the general

  2. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship.

    Science.gov (United States)

    Arem, Hannah; Moore, Steven C; Patel, Alpa; Hartge, Patricia; Berrington de Gonzalez, Amy; Visvanathan, Kala; Campbell, Peter T; Freedman, Michal; Weiderpass, Elisabete; Adami, Hans Olov; Linet, Martha S; Lee, I-Min; Matthews, Charles E

    2015-06-01

    The 2008 Physical Activity Guidelines for Americans recommended a minimum of 75 vigorous-intensity or 150 moderate-intensity minutes per week (7.5 metabolic-equivalent hours per week) of aerobic activity for substantial health benefit and suggested additional benefits by doing more than double this amount. However, the upper limit of longevity benefit or possible harm with more physical activity is unclear. To quantify the dose-response association between leisure time physical activity and mortality and define the upper limit of benefit or harm associated with increased levels of physical activity. We pooled data from 6 studies in the National Cancer Institute Cohort Consortium (baseline 1992-2003). Population-based prospective cohorts in the United States and Europe with self-reported physical activity were analyzed in 2014. A total of 661,137 men and women (median age, 62 years; range, 21-98 years) and 116,686 deaths were included. We used Cox proportional hazards regression with cohort stratification to generate multivariable-adjusted hazard ratios (HRs) and 95% CIs. Median follow-up time was 14.2 years. Leisure time moderate- to vigorous-intensity physical activity. The upper limit of mortality benefit from high levels of leisure time physical activity. Compared with individuals reporting no leisure time physical activity, we observed a 20% lower mortality risk among those performing less than the recommended minimum of 7.5 metabolic-equivalent hours per week (HR, 0.80 [95% CI, 0.78-0.82]), a 31% lower risk at 1 to 2 times the recommended minimum (HR, 0.69 [95% CI, 0.67-0.70]), and a 37% lower risk at 2 to 3 times the minimum (HR, 0.63 [95% CI, 0.62-0.65]). An upper threshold for mortality benefit occurred at 3 to 5 times the physical activity recommendation (HR, 0.61 [95% CI, 0.59-0.62]); however, compared with the recommended minimum, the additional benefit was modest (31% vs 39%). There was no evidence of harm at 10 or more times the recommended minimum (HR

  3. Cabin Environment Physics Risk Model

    Science.gov (United States)

    Mattenberger, Christopher J.; Mathias, Donovan Leigh

    2014-01-01

    This paper presents a Cabin Environment Physics Risk (CEPR) model that predicts the time for an initial failure of Environmental Control and Life Support System (ECLSS) functionality to propagate into a hazardous environment and trigger a loss-of-crew (LOC) event. This physics-of failure model allows a probabilistic risk assessment of a crewed spacecraft to account for the cabin environment, which can serve as a buffer to protect the crew during an abort from orbit and ultimately enable a safe return. The results of the CEPR model replace the assumption that failure of the crew critical ECLSS functionality causes LOC instantly, and provide a more accurate representation of the spacecraft's risk posture. The instant-LOC assumption is shown to be excessively conservative and, moreover, can impact the relative risk drivers identified for the spacecraft. This, in turn, could lead the design team to allocate mass for equipment to reduce overly conservative risk estimates in a suboptimal configuration, which inherently increases the overall risk to the crew. For example, available mass could be poorly used to add redundant ECLSS components that have a negligible benefit but appear to make the vehicle safer due to poor assumptions about the propagation time of ECLSS failures.

  4. Detailed 3D models of the induced electric field of transcranial magnetic stimulation coils

    International Nuclear Information System (INIS)

    Salinas, F S; Lancaster, J L; Fox, P T

    2007-01-01

    Previous models neglected contributions from current elements spanning the full geometric extent of wires in transcranial magnetic stimulation (TMS) coils. A detailed account of TMS coil wiring geometry is shown to provide significant improvements in the accuracy of electric field (E-field) models. Modeling E-field dependence based on the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed E-field models were accurate up to the surface of the coil body (within 0.5% of measured) where simple models were often inadequate (up to 32% different from measured)

  5. Excellence in Physics Education Award: Modeling Theory for Physics Instruction

    Science.gov (United States)

    Hestenes, David

    2014-03-01

    All humans create mental models to plan and guide their interactions with the physical world. Science has greatly refined and extended this ability by creating and validating formal scientific models of physical things and processes. Research in physics education has found that mental models created from everyday experience are largely incompatible with scientific models. This suggests that the fundamental problem in learning and understanding science is coordinating mental models with scientific models. Modeling Theory has drawn on resources of cognitive science to work out extensive implications of this suggestion and guide development of an approach to science pedagogy and curriculum design called Modeling Instruction. Modeling Instruction has been widely applied to high school physics and, more recently, to chemistry and biology, with noteworthy results.

  6. A Multivariate Model of Physics Problem Solving

    Science.gov (United States)

    Taasoobshirazi, Gita; Farley, John

    2013-01-01

    A model of expertise in physics problem solving was tested on undergraduate science, physics, and engineering majors enrolled in an introductory-level physics course. Structural equation modeling was used to test hypothesized relationships among variables linked to expertise in physics problem solving including motivation, metacognitive planning,…

  7. LHC Higgs physics beyond the Standard Model

    International Nuclear Information System (INIS)

    Spannowsky, M.

    2007-01-01

    The Large Hadron Collider (LHC) at CERN will be able to perform proton collisions at a much higher center-of-mass energy and luminosity than any other collider. Its main purpose is to detect the Higgs boson, the last unobserved particle of the Standard Model, explaining the riddle of the origin of mass. Studies have shown, that for the whole allowed region of the Higgs mass processes exist to detect the Higgs at the LHC. However, the Standard Model cannot be a theory of everything and is not able to provide a complete understanding of physics. It is at most an effective theory up to a presently unknown energy scale. Hence, extensions of the Standard Model are necessary which can affect the Higgs-boson signals. We discuss these effects in two popular extensions of the Standard Model: the Minimal Supersymmetric Standard Model (MSSM) and the Standard Model with four generations (SM4G). Constraints on these models come predominantly from flavor physics and electroweak precision measurements. We show, that the SM4G is still viable and that a fourth generation has strong impact on decay and production processes of the Higgs boson. Furthermore, we study the charged Higgs boson in the MSSM, yielding a clear signal for physics beyond the Standard Model. For small tan β in minimal flavor violation (MFV) no processes for the detection of a charged Higgs boson do exist at the LHC. However, MFV is just motivated by the experimental agreement of results from flavor physics with Standard Model predictions, but not by any basic theoretical consideration. In this thesis, we calculate charged Higgs boson production cross sections beyond the assumption of MFV, where a large number of free parameters is present in the MSSM. We find that the soft-breaking parameters which enhance the charged-Higgs boson production most are just bound to large values, e.g. by rare B-meson decays. Although the charged-Higgs boson cross sections beyond MFV turn out to be sizeable, only a detailed

  8. LHC Higgs physics beyond the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Spannowsky, M.

    2007-09-22

    The Large Hadron Collider (LHC) at CERN will be able to perform proton collisions at a much higher center-of-mass energy and luminosity than any other collider. Its main purpose is to detect the Higgs boson, the last unobserved particle of the Standard Model, explaining the riddle of the origin of mass. Studies have shown, that for the whole allowed region of the Higgs mass processes exist to detect the Higgs at the LHC. However, the Standard Model cannot be a theory of everything and is not able to provide a complete understanding of physics. It is at most an effective theory up to a presently unknown energy scale. Hence, extensions of the Standard Model are necessary which can affect the Higgs-boson signals. We discuss these effects in two popular extensions of the Standard Model: the Minimal Supersymmetric Standard Model (MSSM) and the Standard Model with four generations (SM4G). Constraints on these models come predominantly from flavor physics and electroweak precision measurements. We show, that the SM4G is still viable and that a fourth generation has strong impact on decay and production processes of the Higgs boson. Furthermore, we study the charged Higgs boson in the MSSM, yielding a clear signal for physics beyond the Standard Model. For small tan {beta} in minimal flavor violation (MFV) no processes for the detection of a charged Higgs boson do exist at the LHC. However, MFV is just motivated by the experimental agreement of results from flavor physics with Standard Model predictions, but not by any basic theoretical consideration. In this thesis, we calculate charged Higgs boson production cross sections beyond the assumption of MFV, where a large number of free parameters is present in the MSSM. We find that the soft-breaking parameters which enhance the charged-Higgs boson production most are just bound to large values, e.g. by rare B-meson decays. Although the charged-Higgs boson cross sections beyond MFV turn out to be sizeable, only a detailed

  9. Physics beyond the Standard Model

    Science.gov (United States)

    Lach, Theodore

    2011-04-01

    Recent discoveries of the excited states of the Bs** meson along with the discovery of the omega-b-minus have brought into popular acceptance the concept of the orbiting quarks predicted by the Checker Board Model (CBM) 14 years ago. Back then the concept of orbiting quarks was not fashionable. Recent estimates of velocities of these quarks inside the proton and neutron are in excess of 90% the speed of light also in agreement with the CBM model. Still a 2D structure of the nucleus has not been accepted nor has it been proven wrong. The CBM predicts masses of the up and dn quarks are 237.31 MeV and 42.392 MeV respectively and suggests that a lighter generation of quarks u and d make up a different generation of quarks that make up light mesons. The CBM also predicts that the T' and B' quarks do exist and are not as massive as might be expected. (this would make it a 5G world in conflict with the SM) The details of the CB model and prediction of quark masses can be found at: http://checkerboard.dnsalias.net/ (1). T.M. Lach, Checkerboard Structure of the Nucleus, Infinite Energy, Vol. 5, issue 30, (2000). (2). T.M. Lach, Masses of the Sub-Nuclear Particles, nucl-th/0008026, @http://xxx.lanl.gov/.

  10. Models and structures: mathematical physics

    International Nuclear Information System (INIS)

    2003-01-01

    This document gathers research activities along 5 main directions. 1) Quantum chaos and dynamical systems. Recent results concern the extension of the exact WKB method that has led to a host of new results on the spectrum and wave functions. Progress have also been made in the description of the wave functions of chaotic quantum systems. Renormalization has been applied to the analysis of dynamical systems. 2) Combinatorial statistical physics. We see the emergence of new techniques applied to various such combinatorial problems, from random walks to random lattices. 3) Integrability: from structures to applications. Techniques of conformal field theory and integrable model systems have been developed. Progress is still made in particular for open systems with boundary conditions, in connection to strings and branes physics. Noticeable links between integrability and exact WKB quantization to 2-dimensional disordered systems have been highlighted. New correlations of eigenvalues and better connections to integrability have been formulated for random matrices. 4) Gravities and string theories. We have developed aspects of 2-dimensional string theory with a particular emphasis on its connection to matrix models as well as non-perturbative properties of M-theory. We have also followed an alternative path known as loop quantum gravity. 5) Quantum field theory. The results obtained lately concern its foundations, in flat or curved spaces, but also applications to second-order phase transitions in statistical systems

  11. A Model for the Detailed Analysis of Radio Links Involving Tree Canopies

    Directory of Open Access Journals (Sweden)

    F. Perez-Fontan

    2016-12-01

    Full Text Available Detailed analysis of tree canopy interaction with incident radiowaves has mainly been limited to remote sensing for the purpose of forest classification among many other applications. This represents a monostatic configuration, unlike the case of communication links, which are bistatic. In general, link analyses have been limited to the application of simple, empirical formulas based on the use of specific attenuation values in dB/m and the traversed vegetated mass as, e.g., the model in Recommendation ITU-R P.833-8 [1]. In remote sensing, two main techniques are used: Multiple Scattering Theory (MST [2][5] and Radiative Transfer Theory (RT, [5] and [6]. We have paid attention in the past to MST [7][10]. It was shown that a full application of MST leads to very long computation times which are unacceptable in the case where we have to analyze a scenario with several trees. Extensive work using MST has been also presented by others in [11][16] showing the interest in this technique. We have proposed a simplified model for scattering from tree canopies based on a hybridization of MST and a modified physical optics (PO approach [16]. We assume that propagation through a canopy is accounted for by using the complex valued propagation constant obtained by MST. Unlike the case when the full MST is applied, the proposed approach offers significant benefits including a direct software implementation and acceptable computation times even for high frequencies and electrically large canopies. The proposed model thus replaces the coherent component in MST, significant in the forward direction, but keeps the incoherent or diffuse scattering component present in all directions. The incoherent component can be calculated within reasonable times. Here, we present tests of the proposed model against MST using an artificial single-tree scenario at 2 GHz and 10 GHz.

  12. Citygml and the Streets of New York - a Proposal for Detailed Street Space Modelling

    Science.gov (United States)

    Beil, C.; Kolbe, T. H.

    2017-10-01

    Three-dimensional semantic city models are increasingly used for the analysis of large urban areas. Until now the focus has mostly been on buildings. Nonetheless many applications could also benefit from detailed models of public street space for further analysis. However, there are only few guidelines for representing roads within city models. Therefore, related standards dealing with street modelling are examined and discussed. Nearly all street representations are based on linear abstractions. However, there are many use cases that require or would benefit from the detailed geometrical and semantic representation of street space. A variety of potential applications for detailed street space models are presented. Subsequently, based on related standards as well as on user requirements, a concept for a CityGML-compliant representation of street space in multiple levels of detail is developed. In the course of this process, the CityGML Transportation model of the currently valid OGC standard CityGML2.0 is examined to discover possibilities for further developments. Moreover, a number of improvements are presented. Finally, based on open data sources, the proposed concept is implemented within a semantic 3D city model of New York City generating a detailed 3D street space model for the entire city. As a result, 11 thematic classes, such as roadbeds, sidewalks or traffic islands are generated and enriched with a large number of thematic attributes.

  13. A Detailed Experimental and Theoretical Investigation on the Chemical and Physical Behavior of Gold Nanoparticles under X-ray Radiation

    Science.gov (United States)

    Cheng, Neal

    A detailed investigation into the interaction between highly ionizing x-ray radiation and nanomaterials was performed. To begin, a theoretical model of the interactions of the system was created as an attempt to understand the relationship between the nanomaterial and the radiation-generated species. The model spans from the physical regime (10-10 s), during which the chemical species generated from radiolytic cleavage of water diffuses and reacts. A combination of methods was used in the simulation: Monte Carlo, Brownian diffusion, and kinetic rate equations. Several experimental systems were created for the purpose of testing the radio-enhancing effects of nanomaterials and the validity of the model: Firstly, the effects of localized energy deposition by gold nanoparticles were examined in a system consisting of 3 nm gold nanoparticles conjugated to DNA. In this system, single-strand breaks on DNA were used to probe the spatial distribution of energy nanometers around the nanoparticle. A comparison of the local energy deposition by gold nanoparticles versus global energy deposition by water was examined using the model. An additional 150% in DNA strand breaks was observed at 100 mM Tris (2-Amino-2-hydroxymethyl-propane-1,3-diol, represents 5nm diffusion distance), yet according to the model, the energy deposition of 10 gold nanoparticles on a strand of DNA accounts for only an additional 20%. Several explanations were given, such as the different reactivity of radical at short distance, the cross-linking of multiple DNA to a single nanoparticle, and geometric configuration of DNA. Secondly, the effect of remote energy deposition was examined in a system consisting of gold nanotubules and free-floating DNA, containing a composition of 50 wt.% Au/50 wt.% H2O. There was no localized energy deposition due to non-conjugation and a maximum enhancement of 1400% was found at 10 mM Tris, which was inconsistent with the expected enhancement of ˜14000%. The result was

  14. Cost model relationships between textile manufacturing processes and design details for transport fuselage elements

    Science.gov (United States)

    Metschan, Stephen L.; Wilden, Kurtis S.; Sharpless, Garrett C.; Andelman, Rich M.

    1993-01-01

    Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design.

  15. Detailed Modeling of Distillation Technologies for Closed-Loop Water Recovery Systems

    Science.gov (United States)

    Allada, Rama Kumar; Lange, Kevin E.; Anderson, Molly S.

    2011-01-01

    Detailed chemical process simulations are a useful tool in designing and optimizing complex systems and architectures for human life support. Dynamic and steady-state models of these systems help contrast the interactions of various operating parameters and hardware designs, which become extremely useful in trade-study analyses. NASA?s Exploration Life Support technology development project recently made use of such models to compliment a series of tests on different waste water distillation systems. This paper presents efforts to develop chemical process simulations for three technologies: the Cascade Distillation System (CDS), the Vapor Compression Distillation (VCD) system and the Wiped-Film Rotating Disk (WFRD) using the Aspen Custom Modeler and Aspen Plus process simulation tools. The paper discusses system design, modeling details, and modeling results for each technology and presents some comparisons between the model results and recent test data. Following these initial comparisons, some general conclusions and forward work are discussed.

  16. Detailed 3D models of the induced electric field of transcranial magnetic stimulation coils

    Energy Technology Data Exchange (ETDEWEB)

    Salinas, F S; Lancaster, J L; Fox, P T [Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229 (United States)

    2007-05-21

    Previous models neglected contributions from current elements spanning the full geometric extent of wires in transcranial magnetic stimulation (TMS) coils. A detailed account of TMS coil wiring geometry is shown to provide significant improvements in the accuracy of electric field (E-field) models. Modeling E-field dependence based on the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed E-field models were accurate up to the surface of the coil body (within 0.5% of measured) where simple models were often inadequate (up to 32% different from measured)

  17. Author Details

    African Journals Online (AJOL)

    Journal Home > Advanced Search > Author Details ... Design and Implementation of an M/M/1 Queuing Model Algorithm and its Applicability in ... Vehicle Identification Technology to Intercept Small Arms and Ammunition on Nigeria Roads

  18. Kinetics of ethylcyclohexane pyrolysis and oxidation: An experimental and detailed kinetic modeling study

    KAUST Repository

    Wang, Zhandong; Zhao, Long; Wang, Yu; Bian, Huiting; Zhang, Lidong; Zhang, Feng; Li, Yuyang; Sarathy, Mani; Qi, Fei

    2015-01-01

    species were evaluated, and good agreement was observed between the PIMS and GC data sets. Furthermore, a fuel-rich burner-stabilized laminar premixed ECH/O2/Ar flame at 30Torr was studied using synchrotron VUV PIMS. A detailed kinetic model for ECH high

  19. Model reduction of detailed-balanced reaction networks by clustering linkage classes

    NARCIS (Netherlands)

    Rao, Shodhan; Jayawardhana, Bayu; van der Schaft, Abraham; Findeisen, Rolf; Bullinger, Eric; Balsa-Canto, Eva; Bernaerts, Kristel

    2016-01-01

    We propose a model reduction method that involves sequential application of clustering of linkage classes and Kron reduction. This approach is specifically useful for chemical reaction networks with each linkage class having less number of reactions. In case of detailed balanced chemical reaction

  20. Literature Review of Dredging Physical Models

    Science.gov (United States)

    This U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, special report presents a review of dredging physical ...model studies with the goal of understanding the most current state of dredging physical modeling, understanding conditions of similitude used in past...studies, and determining whether the flow field around a dredging operation has been quantified. Historical physical modeling efforts have focused on

  1. Detailed High Frequency Models of Various Winding Types in Power Transformers

    DEFF Research Database (Denmark)

    Pedersen, Kenneth; Lunow, Morten Erlandsson; Holbøll, Joachim

    2005-01-01

    Abstract--In this paper, techniques are described which demonstrate how a highly detailed internal transformer model can be obtained systematically with Matlab and how it can be prepared for subsequent transient analysis. The input of such a model will mainly be the description of the cross secti...... equivalent circuit. Finally a new circuit extraction technique is proposed for vector fitted impedance matrices for more efficient computation....

  2. A detailed aerosol mixing state model for investigating interactions between mixing state, semivolatile partitioning, and coagulation

    OpenAIRE

    J. Lu; F. M. Bowman

    2010-01-01

    A new method for describing externally mixed particles, the Detailed Aerosol Mixing State (DAMS) representation, is presented in this study. This novel method classifies aerosols by both composition and size, using a user-specified mixing criterion to define boundaries between compositional populations. Interactions between aerosol mixing state, semivolatile partitioning, and coagulation are investigated with a Lagrangian box model that incorporates the DAMS approach. Model results predict th...

  3. Evaluating a Model of Youth Physical Activity

    Science.gov (United States)

    Heitzler, Carrie D.; Lytle, Leslie A.; Erickson, Darin J.; Barr-Anderson, Daheia; Sirard, John R.; Story, Mary

    2010-01-01

    Objective: To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. Methods: Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a…

  4. Comparison of Detailed and Simplified Models of Human Atrial Myocytes to Recapitulate Patient Specific Properties.

    Directory of Open Access Journals (Sweden)

    Daniel M Lombardo

    2016-08-01

    Full Text Available Computer studies are often used to study mechanisms of cardiac arrhythmias, including atrial fibrillation (AF. A crucial component in these studies is the electrophysiological model that describes the membrane potential of myocytes. The models vary from detailed, describing numerous ion channels, to simplified, grouping ionic channels into a minimal set of variables. The parameters of these models, however, are determined across different experiments in varied species. Furthermore, a single set of parameters may not describe variations across patients, and models have rarely been shown to recapitulate critical features of AF in a given patient. In this study we develop physiologically accurate computational human atrial models by fitting parameters of a detailed and of a simplified model to clinical data for five patients undergoing ablation therapy. Parameters were simultaneously fitted to action potential (AP morphology, action potential duration (APD restitution and conduction velocity (CV restitution curves in these patients. For both models, our fitting procedure generated parameter sets that accurately reproduced clinical data, but differed markedly from published sets and between patients, emphasizing the need for patient-specific adjustment. Both models produced two-dimensional spiral wave dynamics for that were similar for each patient. These results show that simplified, computationally efficient models are an attractive choice for simulations of human atrial electrophysiology in spatially extended domains. This study motivates the development and validation of patient-specific model-based mechanistic studies to target therapy.

  5. Recent developments in the detailed modelling of power house environmental conditions using GOTHIC

    International Nuclear Information System (INIS)

    Wong, R.C.; Fluke, R.J.; Yim, K.; Rossitter, B.G.

    1997-01-01

    Environmental qualification of safety equipment in the powerhouse requires detailed information on the predicted harsh conditions that can arise following a steam line break. Although lumped parameter codes provide quick assessments of global conditions, the results are unsatisfactory because the spatial detail needed to evaluate specific equipment, or indeed to optimize and confirm the design adequacy of mitigating features, is not available. To overcome these problems, new models have been developed to provide detailed three-dimensional information using the GOTHIC code. Furthermore, new animated graphical displays help the designer visualize and fully comprehend the buoyancy driven steam flow within the powerhouse. This has lead to quick optimization of the placement, size and opening time of the emergency venting system, thereby mitigating the conditions for which safety equipment must be qualified. This has resulted in significant cost savings for the environmental qualification programme. (author)

  6. One Curve Embedded Full-Bridge MMC Modeling Method with Detailed Representation of IGBT Characteristics

    Science.gov (United States)

    Hongyang, Yu; Zhengang, Lu; Xi, Yang

    2017-05-01

    Modular Multilevel Converter is more and more widely used in high voltage DC transmission system and high power motor drive system. It is a major topological structure for high power AC-DC converter. Due to the large module number, the complex control algorithm, and the high power user’s back ground, the MMC model used for simulation should be as accurate as possible to simulate the details of how MMC works for the dynamic testing of the MMC controller. But so far, there is no sample simulation MMC model which can simulate the switching dynamic process. In this paper, one curve embedded full-bridge MMC modeling method with detailed representation of IGBT characteristics is proposed. This method is based on the switching curve referring and sample circuit calculation, and it is sample for implementation. Based on the simulation comparison test under Matlab/Simulink, the proposed method is proved to be correct.

  7. Technical Manual for the SAM Physical Trough Model

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  8. Modeling the Emission of CO from Wood Fires using Detailed Chemical Kinetics

    DEFF Research Database (Denmark)

    Dederichs, Anne

    Carbon monoxide is treated as one of the most common and dangerous of gases evolving in fires. Modeling the formation of the toxic gas CO from in fire enclosures using detailed chemical kinetics is the topic of this manuscript. A semi-empirical model is developed to study the formation of CO from......, the model separately treats the process of pyrolysis and combustion. For under ventilated conditions and at high temperatures during pyrolysis it is found that the process of pyrolysation strongly influences the formation of CO in fire. CO2 follows the same trend....

  9. A validated physical model of greenhouse climate.

    NARCIS (Netherlands)

    Bot, G.P.A.

    1989-01-01

    In the greenhouse model the momentaneous environmental crop growth factors are calculated as output, together with the physical behaviour of the crop. The boundary conditions for this model are the outside weather conditions; other inputs are the physical characteristics of the crop, of the

  10. Analytical calculation of detailed model parameters of cast resin dry-type transformers

    International Nuclear Information System (INIS)

    Eslamian, M.; Vahidi, B.; Hosseinian, S.H.

    2011-01-01

    Highlights: → In this paper high frequency behavior of cast resin dry-type transformers was simulated. → Parameters of detailed model were calculated using analytical method and compared with FEM results. → A lab transformer was constructed in order to compare theoretical and experimental results. -- Abstract: Non-flammable characteristic of cast resin dry-type transformers make them suitable for different kind of usages. This paper presents an analytical method of how to obtain parameters of detailed model of these transformers. The calculated parameters are compared and verified with the corresponding FEM results and if it was necessary, correction factors are introduced for modification of the analytical solutions. Transient voltages under full and chopped test impulses are calculated using the obtained detailed model. In order to validate the model, a setup was constructed for testing on high-voltage winding of cast resin dry-type transformer. The simulation results were compared with the experimental data measured from FRA and impulse tests.

  11. Study on detailed geological modelling for fluvial sandstone reservoir in Daqing oil field

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hanqing; Fu Zhiguo; Lu Xiaoguang [Institute of Petroleum Exploration and Development, Daqing (China)

    1997-08-01

    Guided by the sedimentation theory and knowledge of modern and ancient fluvial deposition and utilizing the abundant information of sedimentary series, microfacies type and petrophysical parameters from well logging curves of close spaced thousands of wells located in a large area. A new method for establishing detailed sedimentation and permeability distribution models for fluvial reservoirs have been developed successfully. This study aimed at the geometry and internal architecture of sandbodies, in accordance to their hierarchical levels of heterogeneity and building up sedimentation and permeability distribution models of fluvial reservoirs, describing the reservoir heterogeneity on the light of the river sedimentary rules. The results and methods obtained in outcrop and modem sedimentation studies have successfully supported the study. Taking advantage of this method, the major producing layers (PI{sub 1-2}), which have been considered as heterogeneous and thick fluvial reservoirs extending widely in lateral are researched in detail. These layers are subdivided into single sedimentary units vertically and the microfacies are identified horizontally. Furthermore, a complex system is recognized according to their hierarchical levels from large to small, meander belt, single channel sandbody, meander scroll, point bar, and lateral accretion bodies of point bar. The achieved results improved the description of areal distribution of point bar sandbodies, provide an accurate and detailed framework model for establishing high resolution predicting model. By using geostatistic technique, it also plays an important role in searching for enriched zone of residual oil distribution.

  12. The i-V curve characteristics of burner-stabilized premixed flames: detailed and reduced models

    KAUST Repository

    Han, Jie

    2016-07-17

    The i-V curve describes the current drawn from a flame as a function of the voltage difference applied across the reaction zone. Since combustion diagnostics and flame control strategies based on electric fields depend on the amount of current drawn from flames, there is significant interest in modeling and understanding i-V curves. We implement and apply a detailed model for the simulation of the production and transport of ions and electrons in one-dimensional premixed flames. An analytical reduced model is developed based on the detailed one, and analytical expressions are used to gain insight into the characteristics of the i-Vcurve for various flame configurations. In order for the reduced model to capture the spatial distribution of the electric field accurately, the concept of a dead zone region, where voltage is constant, is introduced, and a suitable closure for the spatial extent of the dead zone is proposed and validated. The results from the reduced modeling framework are found to be in good agreement with those from the detailed simulations. The saturation voltage is found to depend significantly on the flame location relative to the electrodes, and on the sign of the voltage difference applied. Furthermore, at sub-saturation conditions, the current is shown to increase linearly or quadratically with the applied voltage, depending on the flame location. These limiting behaviors exhibited by the reduced model elucidate the features of i-V curves observed experimentally. The reduced model relies on the existence of a thin layer where charges are produced, corresponding to the reaction zone of a flame. Consequently, the analytical model we propose is not limited to the study of premixed flames, and may be applied easily to others configurations, e.g.~nonpremixed counterflow flames.

  13. MIDA: A Multimodal Imaging-Based Detailed Anatomical Model of the Human Head and Neck.

    Directory of Open Access Journals (Sweden)

    Maria Ida Iacono

    Full Text Available Computational modeling and simulations are increasingly being used to complement experimental testing for analysis of safety and efficacy of medical devices. Multiple voxel- and surface-based whole- and partial-body models have been proposed in the literature, typically with spatial resolution in the range of 1-2 mm and with 10-50 different tissue types resolved. We have developed a multimodal imaging-based detailed anatomical model of the human head and neck, named "MIDA". The model was obtained by integrating three different magnetic resonance imaging (MRI modalities, the parameters of which were tailored to enhance the signals of specific tissues: i structural T1- and T2-weighted MRIs; a specific heavily T2-weighted MRI slab with high nerve contrast optimized to enhance the structures of the ear and eye; ii magnetic resonance angiography (MRA data to image the vasculature, and iii diffusion tensor imaging (DTI to obtain information on anisotropy and fiber orientation. The unique multimodal high-resolution approach allowed resolving 153 structures, including several distinct muscles, bones and skull layers, arteries and veins, nerves, as well as salivary glands. The model offers also a detailed characterization of eyes, ears, and deep brain structures. A special automatic atlas-based segmentation procedure was adopted to include a detailed map of the nuclei of the thalamus and midbrain into the head model. The suitability of the model to simulations involving different numerical methods, discretization approaches, as well as DTI-based tensorial electrical conductivity, was examined in a case-study, in which the electric field was generated by transcranial alternating current stimulation. The voxel- and the surface-based versions of the models are freely available to the scientific community.

  14. Devil is in the details: Using logic models to investigate program process.

    Science.gov (United States)

    Peyton, David J; Scicchitano, Michael

    2017-12-01

    Theory-based logic models are commonly developed as part of requirements for grant funding. As a tool to communicate complex social programs, theory based logic models are an effective visual communication. However, after initial development, theory based logic models are often abandoned and remain in their initial form despite changes in the program process. This paper examines the potential benefits of committing time and resources to revising the initial theory driven logic model and developing detailed logic models that describe key activities to accurately reflect the program and assist in effective program management. The authors use a funded special education teacher preparation program to exemplify the utility of drill down logic models. The paper concludes with lessons learned from the iterative revision process and suggests how the process can lead to more flexible and calibrated program management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. A structurally detailed finite element human head model for simulation of transcranial magnetic stimulation.

    Science.gov (United States)

    Chen, Ming; Mogul, David Jeffery

    2009-04-30

    Computational studies of the head utilizing finite element models (FEMs) have been used to investigate a wide variety of brain-electromagnetic (EM) field interaction phenomena including magnetic stimulation of the head using transcranial magnetic stimulation (TMS), direct electric stimulation of the brain for electroconvulsive therapy, and electroencephalography source localization. However, no human head model of sufficient complexity for studying the biophysics under these circumstances has been developed which utilizes structures at both the regional and cellular levels and provides well-defined smooth boundaries between tissues of different conductivities and orientations. The main barrier for building such accurate head models is the complex modeling procedures that include 3D object reconstruction and optimized meshing. In this study, a structurally detailed finite element model of the human head was generated that includes details to the level of cerebral gyri and sulci by combining computed tomography and magnetic resonance images. Furthermore, cortical columns that contain conductive processes of pyramidal neurons traversing the neocortical layers were included in the head model thus providing structure at or near the cellular level. These refinements provide a much more realistic model to investigate the effects of TMS on brain electrophysiology in the neocortex.

  16. CONSTRUCTION OF AGGREGATE NATIONAL ECONOMIC MODEL WITH DETAILED REPRESENTATION OF THE FOREST COMPLEX

    Directory of Open Access Journals (Sweden)

    Blam Yu. Sh.

    2014-09-01

    Full Text Available Autonomy of the industrial forecasts often exacerbated by the lack of direct connection with the economic forecasts on the macro level. On the other hand it is desirable to simulate the industrial strategy in a fairly high degree of isolation, so that it does not depend at every moment on description of other activities or levels of hierarchy. To study the effects of national economic relations on the development of industrial complex we propose to use a spatial model of the national economy, which describes modalities of the researched industries in more detail. Quantitative parameters, obtained using basic Interregional Cross-sectoral Optimization Model (OMMM against the external development of the industrial complex, are used to form an aggregated model with a detailed representation with unsignificant loss of information. Thus, the above described model is intended to harmonize national economic decisions with forecasts obtained from industry models in real terms. The conversion procedure is based on the properties of the model of «mutual» problems and information from basic OMMM. The final result is a production-transport cost model within a «traditional» industrial structure.

  17. Numerical modelling in material physics

    International Nuclear Information System (INIS)

    Proville, L.

    2004-12-01

    The author first briefly presents his past research activities: investigation of a dislocation sliding in solid solution by molecular dynamics, modelling of metal film growth by phase field and Monte Carlo kinetics, phase field model for surface self-organisation, phase field model for the Al 3 Zr alloy, calculation of anharmonic photons, mobility of bipolarons in superconductors. Then, he more precisely reports the mesoscopic modelling in phase field, and some atomistic modelling (dislocation sliding, Monte Carlo simulation of metal surface growth, anharmonic network optical spectrum modelling)

  18. Detailed dynamic solid oxide fuel cell modeling for electrochemical impedance spectra simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Ph. [Laboratory of Steam Boilers and Thermal Plants, School of Mechanical Engineering, Thermal Engineering Section, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens (Greece); Panopoulos, K.D. [Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 4th km. Ptolemais-Mpodosakeio Hospital, Region of Kouri, P.O. Box 95, GR 502, 50200 Ptolemais (Greece)

    2010-08-15

    This paper presents a detailed flexible mathematical model for planar solid oxide fuel cells (SOFCs), which allows the simulation of steady-state performance characteristics, i.e. voltage-current density (V-j) curves, and dynamic operation behavior, with a special capability of simulating electrochemical impedance spectroscopy (EIS). The model is based on physico-chemical governing equations coupled with a detailed multi-component gas diffusion mechanism (Dusty-Gas Model (DGM)) and a multi-step heterogeneous reaction mechanism implicitly accounting for the water-gas-shift (WGS), methane reforming and Boudouard reactions. Spatial discretization can be applied for 1D (button-cell approximation) up to quasi-3D (full size anode supported cell in cross-flow configuration) geometries and is resolved with the finite difference method (FDM). The model is built and implemented on the commercially available modeling and simulations platform gPROMS trademark. Different fuels based on hydrogen, methane and syngas with inert diluents are run. The model is applied to demonstrate a detailed analysis of the SOFC inherent losses and their attribution to the EIS. This is achieved by means of a step-by-step analysis of the involved transient processes such as gas conversion in the main gas chambers/channels, gas diffusion through the porous electrodes together with the heterogeneous reactions on the nickel catalyst, and the double-layer current within the electrochemical reaction zone. The model is an important tool for analyzing SOFC performance fundamentals as well as for design and optimization of materials' and operational parameters. (author)

  19. Detailed clinical models: representing knowledge, data and semantics in healthcare information technology.

    Science.gov (United States)

    Goossen, William T F

    2014-07-01

    This paper will present an overview of the developmental effort in harmonizing clinical knowledge modeling using the Detailed Clinical Models (DCMs), and will explain how it can contribute to the preservation of Electronic Health Records (EHR) data. Clinical knowledge modeling is vital for the management and preservation of EHR and data. Such modeling provides common data elements and terminology binding with the intention of capturing and managing clinical information over time and location independent from technology. Any EHR data exchange without an agreed clinical knowledge modeling will potentially result in loss of information. Many attempts exist from the past to model clinical knowledge for the benefits of semantic interoperability using standardized data representation and common terminologies. The objective of each project is similar with respect to consistent representation of clinical data, using standardized terminologies, and an overall logical approach. However, the conceptual, logical, and the technical expressions are quite different in one clinical knowledge modeling approach versus another. There currently are synergies under the Clinical Information Modeling Initiative (CIMI) in order to create a harmonized reference model for clinical knowledge models. The goal for the CIMI is to create a reference model and formalisms based on for instance the DCM (ISO/TS 13972), among other work. A global repository of DCMs may potentially be established in the future.

  20. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T; Kilpinen, P; Hupa, M [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1997-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  1. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T.; Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1996-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  2. Problems in physical modeling of magnetic materials

    International Nuclear Information System (INIS)

    Della Torre, E.

    2004-01-01

    Physical modeling of magnetic materials should give insights into the basic processes involved and should be able to extrapolate results to new situations that the models were not necessarily intended to solve. Thus, for example, if a model is designed to describe a static magnetization curve, it should also be able to describe aspects of magnetization dynamics. Both micromagnetic modeling and Preisach modeling, the two most popular magnetic models, fulfill this requirement, but in the process of fulfilling this requirement, they both had to be modified in some ways. Hence, we should view physical modeling as an iterative process whereby we start with some simple assumptions and refine them as reality requires. In the process of refining these assumptions, we should try to appeal to physical arguments for the modifications, if we are to come up with good models. If we consider phenomenological models, on the other hand, that is as axiomatic models requiring no physical justification, we can follow them logically to see the end and examine the consequences of their assumptions. In this way, we can learn the properties, limitations and achievements of the particular model. Physical and phenomenological models complement each other in furthering our understanding of the behavior of magnetic materials

  3. A state-space model for estimating detailed movements and home range from acoustic receiver data

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Weng, Kevin

    2013-01-01

    We present a state-space model for acoustic receiver data to estimate detailed movement and home range of individual fish while accounting for spatial bias. An integral part of the approach is the detection function, which models the probability of logging tag transmissions as a function of dista......We present a state-space model for acoustic receiver data to estimate detailed movement and home range of individual fish while accounting for spatial bias. An integral part of the approach is the detection function, which models the probability of logging tag transmissions as a function...... that the location error scales log-linearly with detection range and movement speed. This result can be used as guideline for designing network layout when species movement capacity and acoustic environment are known or can be estimated prior to network deployment. Finally, as an example, the state-space model...... is used to estimate home range and movement of a reef fish in the Pacific Ocean....

  4. High precision Standard Model Physics

    International Nuclear Information System (INIS)

    Magnin, J.

    2009-01-01

    The main goal of the LHCb experiment, one of the four large experiments of the Large Hadron Collider, is to try to give answers to the question of why Nature prefers matter over antimatter? This will be done by studying the decay of b quarks and their antimatter partners, b-bar, which will be produced by billions in 14 TeV p-p collisions by the LHC. In addition, as 'beauty' particles mainly decay in charm particles, an interesting program of charm physics will be carried on, allowing to measure quantities as for instance the D 0 -D-bar 0 mixing, with incredible precision.

  5. Kinetics of ethylcyclohexane pyrolysis and oxidation: An experimental and detailed kinetic modeling study

    KAUST Repository

    Wang, Zhandong

    2015-07-01

    Ethylcyclohexane (ECH) is a model compound for cycloalkanes with long alkyl side-chains. A preliminary investigation on ECH (Wang et al., Proc. Combust. Inst., 35, 2015, 367-375) revealed that an accurate ECH kinetic model with detailed fuel consumption mechanism and aromatic growth pathways, as well as additional ECH pyrolysis and oxidation data with detailed species concentration covering a wide pressure and temperature range are required to understand the ECH combustion kinetics. In this work, the flow reactor pyrolysis of ECH at various pressures (30, 150 and 760Torr) was studied using synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (PIMS) and gas chromatography (GC). The mole fraction profiles of numerous major and minor species were evaluated, and good agreement was observed between the PIMS and GC data sets. Furthermore, a fuel-rich burner-stabilized laminar premixed ECH/O2/Ar flame at 30Torr was studied using synchrotron VUV PIMS. A detailed kinetic model for ECH high temperature pyrolysis and oxidation was developed and validated against the pyrolysis and flame data performed in this work. Further validation of the kinetic model is presented against literature data including species concentrations in jet-stirred reactor oxidation, ignition delay times in a shock tube, and laminar flame speeds at various pressures and equivalence ratios. The model well predicts the consumption of ECH, the growth of aromatics, and the global combustion properties. Reaction flux and sensitivity analysis were utilized to elucidate chemical kinetic features of ECH combustion under various reaction conditions. © 2015 The Combustion Institute.

  6. Integration of snow management practices into a detailed snow pack model

    Science.gov (United States)

    Spandre, Pierre; Morin, Samuel; Lafaysse, Matthieu; Lejeune, Yves; François, Hugues; George-Marcelpoil, Emmanuelle

    2016-04-01

    The management of snow on ski slopes is a key socio-economic and environmental issue in mountain regions. Indeed the winter sports industry has become a very competitive global market although this economy remains particularly sensitive to weather and snow conditions. The understanding and implementation of snow management in detailed snowpack models is a major step towards a more realistic assessment of the evolution of snow conditions in ski resorts concerning past, present and future climate conditions. Here we describe in a detailed manner the integration of snow management processes (grooming, snowmaking) into the snowpack model Crocus (Spandre et al., Cold Reg. Sci. Technol., in press). The effect of the tiller is explicitly taken into account and its effects on snow properties (density, snow microstructure) are simulated in addition to the compaction induced by the weight of the grooming machine. The production of snow in Crocus is carried out with respect to specific rules and current meteorological conditions. Model configurations and results are described in detail through sensitivity tests of the model of all parameters related to snow management processes. In-situ observations were carried out in four resorts in the French Alps during the 2014-2015 winter season considering for each resort natural, groomed only and groomed plus snowmaking conditions. The model provides realistic simulations of the snowpack properties with respect to these observations. The main uncertainty pertains to the efficiency of the snowmaking process. The observed ratio between the mass of machine-made snow on ski slopes and the water mass used for production was found to be lower than was expected from the literature, in every resort. The model now referred to as "Crocus-Resort" has been proven to provide realistic simulations of snow conditions on ski slopes and may be used for further investigations. Spandre, P., S. Morin, M. Lafaysse, Y. Lejeune, H. François and E. George

  7. Unification and mechanistic detail as drivers of model construction: models of networks in economics and sociology.

    Science.gov (United States)

    Kuorikoski, Jaakko; Marchionni, Caterina

    2014-12-01

    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant.

  8. Physics Based Modeling of Compressible Turbulance

    Science.gov (United States)

    2016-11-07

    AFRL-AFOSR-VA-TR-2016-0345 PHYSICS -BASED MODELING OF COMPRESSIBLE TURBULENCE PARVIZ MOIN LELAND STANFORD JUNIOR UNIV CA Final Report 09/13/2016...on the AFOSR project (FA9550-11-1-0111) entitled: Physics based modeling of compressible turbulence. The period of performance was, June 15, 2011...by ANSI Std. Z39.18 Page 1 of 2FORM SF 298 11/10/2016https://livelink.ebs.afrl.af.mil/livelink/llisapi.dll PHYSICS -BASED MODELING OF COMPRESSIBLE

  9. Modeling transient luminous events produced by cloud to ground lightning and narrow bipolar pulses: detailed spectra and chemical impact

    Science.gov (United States)

    Perez-Invernon, F. J.; Luque, A.; Gordillo-Vazquez, F. J.

    2017-12-01

    The electromagnetic field generated by lightning discharges can produce Transient Luminous Events (TLEs) in the lower ionosphere, as previously investigated by many authors. Some recent studies suggest that narrow bipolar pulses (NBP), an impulsive and not well-established type of atmospheric electrical discharge, could also produce TLEs. The characterization and observation of such TLEs could be a source of information about the physics underlying NBP. In this work, we develop two different electrodynamical models to study the impact of lightning-driven electromagnetic fields in the lower ionosphere. The first model calculates the quasi-electrostatic field produced by a single cloud to ground lightning in the terrestrial atmosphere and its influence in the electron transport. This scheme allows us to study halos, a relatively frequent type of TLE. The second model solves the Maxwell equations for the electromagnetic field produced by a lightning discharge coupled with the Langevin's equation for the induced currents in the ionosphere. This model is useful to investigate elves, a fast TLE produced by lightning or by NBP. In addition, both models are coupled with a detailed chemistry of the electronically and vibrationally excited states of molecular nitrogen, allowing us to calculate synthetic spectra of both halos and elves. The models also include a detailed set of kinetic reactions to calculate the temporal evolution of other species. Our results suggest an important enhancement of some molecular species produced by halos, as NOx , N2 O and other metastable species. The quantification of their production could be useful to understand the role of thunderstorms in the climate of our planet. In the case of TLEs produced by NBP, our model confirms the appearance of double elves and allows us to compute their spectral characteristics.

  10. The Physical Internet and Business Model Innovation

    Directory of Open Access Journals (Sweden)

    Diane Poulin

    2012-06-01

    Full Text Available Building on the analogy of data packets within the Digital Internet, the Physical Internet is a concept that dramatically transforms how physical objects are designed, manufactured, and distributed. This approach is open, efficient, and sustainable beyond traditional proprietary logistical solutions, which are often plagued by inefficiencies. The Physical Internet redefines supply chain configurations, business models, and value-creation patterns. Firms are bound to be less dependent on operational scale and scope trade-offs because they will be in a position to offer novel hybrid products and services that would otherwise destroy value. Finally, logistical chains become flexible and reconfigurable in real time, thus becoming better in tune with firm strategic choices. This article focuses on the potential impact of the Physical Internet on business model innovation, both from the perspectives of Physical-Internet enabled and enabling business models.

  11. Random detailed model for probabilistic neutronic calculation in pebble bed Very High Temperature Reactors

    International Nuclear Information System (INIS)

    Perez Curbelo, J.; Rosales, J.; Garcia, L.; Garcia, C.; Brayner, C.

    2013-01-01

    The pebble bed nuclear reactor is one of the main candidates for the next generation of nuclear power plants. In pebble bed type HTRs, the fuel is contained within graphite pebbles in the form of TRISO particles, which form a randomly packed bed inside a graphite-walled cylindrical cavity. Pebble bed reactors (PBR) offer the opportunity to meet the sustainability requirements, such as nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. In order to simulate PBRs correctly, the double heterogeneity of the system must be considered. It consists on randomly located pebbles into the core and TRISO particles into the fuel pebbles. These features are often neglected due to the difficulty to model with MCPN code. The main reason is that there is a limited number of cells and surfaces to be defined. In this study, a computational tool which allows getting a new geometrical model of fuel pebbles for neutronic calculations with MCNPX code, was developed. The heterogeneity of system is considered, and also the randomly located TRISO particles inside the pebble. Four proposed fuel pebble models were compared regarding their effective multiplication factor and energy liberation profiles. Such models are: Homogeneous Pebble, Five Zone Homogeneous Pebble, Detailed Geometry, and Randomly Detailed Geometry. (Author)

  12. Axon-somatic back-propagation in detailed models of spinal alpha motoneurons

    Directory of Open Access Journals (Sweden)

    Pietro eBalbi

    2015-02-01

    Full Text Available Antidromic action potentials following distal stimulation of motor axons occasionally fail to invade the soma of alpha motoneurons in spinal cord, due to their passing through regions of high non-uniformity.Morphologically detailed conductance-based models of cat spinal alpha motoneurons have been developed, with the aim to reproduce and clarify some aspects of the electrophysiological behavior of the antidromic axon-somatic spike propagation. Fourteen 3D morphologically detailed somata and dendrites of cat spinal alpha motoneurons have been imported from an open-access web-based database of neuronal morphologies, NeuroMorpho.org, and instantiated in neurocomputational models. An axon hillock, an axonal initial segment and a myelinated axon are added to each model.By sweeping the diameter of the axonal initial segment (AIS and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically travelling wave.In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

  13. Are Physical Education Majors Models for Fitness?

    Science.gov (United States)

    Kamla, James; Snyder, Ben; Tanner, Lori; Wash, Pamela

    2012-01-01

    The National Association of Sport and Physical Education (NASPE) (2002) has taken a firm stance on the importance of adequate fitness levels of physical education teachers stating that they have the responsibility to model an active lifestyle and to promote fitness behaviors. Since the NASPE declaration, national initiatives like Let's Move…

  14. Quark models in hadron physics

    International Nuclear Information System (INIS)

    Phatak, Shashikant C.

    2007-01-01

    In this talk, we review the role played by the quark models in the study of interaction of strong, weak and electromagnetic probes with hadrons at intermediate and high momentum transfers. By hadrons, we mean individual nucleons as well as nuclei. We argue that at these momentum transfers, the structure of hadrons plays an important role. The hadron structure of the hadrons is because of the underlying quark structure of hadrons and therefore the quark models play an important role in determining the hadron structure. Further, the properties of hadrons are likely to change when these are placed in nuclear medium and this change should arise from the underlying quark structure. We shall consider some quark models to look into these aspects. (author)

  15. Author Details

    African Journals Online (AJOL)

    Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text ... Abstract · Vol 17 (2010) - Articles Investigating The Travelling Wave Solution For an SIR Endemic Disease Model With No Disease Related Death (When The Spatial Spread Of The Susceptible Is Not Negligible). Abstract.

  16. Physics of the Quark Model

    Science.gov (United States)

    Young, Robert D.

    1973-01-01

    Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)

  17. APT Blanket Detailed Bin Model Based on Initial Plate-Type Design -3D FLOWTRAN-TF Model

    International Nuclear Information System (INIS)

    Hamm, L.L.

    1998-01-01

    This report provides background information for a series of reports documenting accident scenario simulations for the Accelerator Production of Tritium (APT) blanket heat removal systems. The simulations were performed in support of the Preliminary Safety Analysis Report for the APT. This report gives a brief description of the FLOWTRAN-TF code which was used for detailed blanket bin modeling

  18. Simplified Models for LHC New Physics Searches

    CERN Document Server

    Alves, Daniele; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait, Tim; Thomas, Brooks; Thomas, Scott; Toro, Natalia; Volansky, Tomer; Wacker, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn

    2012-01-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a...

  19. Automatic Generation of Building Models with Levels of Detail 1-3

    Science.gov (United States)

    Nguatem, W.; Drauschke, M.; Mayer, H.

    2016-06-01

    We present a workflow for the automatic generation of building models with levels of detail (LOD) 1 to 3 according to the CityGML standard (Gröger et al., 2012). We start with orienting unsorted image sets employing (Mayer et al., 2012), we compute depth maps using semi-global matching (SGM) (Hirschmüller, 2008), and fuse these depth maps to reconstruct dense 3D point clouds (Kuhn et al., 2014). Based on planes segmented from these point clouds, we have developed a stochastic method for roof model selection (Nguatem et al., 2013) and window model selection (Nguatem et al., 2014). We demonstrate our workflow up to the export into CityGML.

  20. Incorporation of detailed eye model into polygon-mesh versions of ICRP-110 reference phantoms.

    Science.gov (United States)

    Nguyen, Thang Tat; Yeom, Yeon Soo; Kim, Han Sung; Wang, Zhao Jun; Han, Min Cheol; Kim, Chan Hyeong; Lee, Jai Ki; Zankl, Maria; Petoussi-Henss, Nina; Bolch, Wesley E; Lee, Choonsik; Chung, Beom Sun

    2015-11-21

    The dose coefficients for the eye lens reported in ICRP 2010 Publication 116 were calculated using both a stylized model and the ICRP-110 reference phantoms, according to the type of radiation, energy, and irradiation geometry. To maintain consistency of lens dose assessment, in the present study we incorporated the ICRP-116 detailed eye model into the converted polygon-mesh (PM) version of the ICRP-110 reference phantoms. After the incorporation, the dose coefficients for the eye lens were calculated and compared with those of the ICRP-116 data. The results showed generally a good agreement between the newly calculated lens dose coefficients and the values of ICRP 2010 Publication 116. Significant differences were found for some irradiation cases due mainly to the use of different types of phantoms. Considering that the PM version of the ICRP-110 reference phantoms preserve the original topology of the ICRP-110 reference phantoms, it is believed that the PM version phantoms, along with the detailed eye model, provide more reliable and consistent dose coefficients for the eye lens.

  1. Detailed geologic modeling of a turbidity reservoir interval at the Mars discovery

    Energy Technology Data Exchange (ETDEWEB)

    Mahaffie, M.J.; Chapin, M.A. [Shell Exploration and Production Technology Co. (United States); Henry, W.A. [Shell Offshore, Inc. (United States)

    1995-12-31

    Detailed reservoir architecture studies using high resolution seismic data coupled with geologic and seismic inversion modeling have been used to evaluate a major hydrocarbon bearing turbidite reservoir found within Prospect Mars. Early interpretations of this interval, based on lower frequency (40 Hz) seismic data, indicated the presence of a single, laterally continuous event covering an area nearly 3 miles square ({approx} 5200 acres). Correlations from well control supported the notion that this seismic event comprised a series of continuous sheet sands exhibiting a high degree of lateral continuity and connectivity. However pressure data taken during fluid sampling of the reservoir suggested the possibility of discontinuities not observed within the resolution of the seismic data. Seismic reprocessing enhancements to increase frequency content revealed the presence of multiple stratigraphic features not previously recognized. Detailed seismic mapping using loop-level seismic attributes and seismic inversion studies constrained by geologic models provide a more realistic depiction of the environment of deposition and improve reservoir simulation modeling for this stratigraphic interval. (author). 3 figs

  2. Detailed CATHENA Model of the Wolsong 1 Pressure and Inventory Control System

    Energy Technology Data Exchange (ETDEWEB)

    Cha, K.H. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    The Detailed CATHENA model of Wolsong 1 is development to be able to simulate a theramal hydraulic behavior of heat transport system(HTS) Pressure and Inventory Control System(PNIC) at any power operation condition and during transient events such as mall LOCA(small loss of coolant inventory and small breaks in the primary system piping) and non-LOCA(loss of reactivity regulation, loss of flow, loss if Class IV power, loss of PNIC). (author). 12 refs., 7 figs., 6 tabs.

  3. Exact correlations in the Lieb-Liniger model and detailed balance out-of-equilibrium

    Directory of Open Access Journals (Sweden)

    Jacopo De Nardis, Miłosz Panfil

    2016-12-01

    Full Text Available We study the density-density correlation function of the 1D Lieb-Liniger model and obtain an exact expression for the small momentum limit of the static correlator in the thermodynamic limit. We achieve this by summing exactly over the relevant form factors of the density operator in the small momentum limit. The result is valid for any eigenstate, including thermal and non-thermal states. We also show that the small momentum limit of the dynamic structure factors obeys a generalized detailed balance relation valid for any equilibrium state.

  4. Deciphering the details of RNA aminoglycoside interactions: from atomistic models to biotechnological applications

    Energy Technology Data Exchange (ETDEWEB)

    Ilgu, Muslum [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    A detailed study was done of the neomycin-B RNA aptamer for determining its selectivity and binding ability to both neomycin– and kanamycin-class aminoglycosides. A novel method to increase drug concentrations in cells for more efficiently killing is described. To test the method, a bacterial model system was adopted and several small RNA molecules interacting with aminoglycosides were cloned downstream of T7 RNA polymerase promoter in an expression vector. Then, the growth analysis of E. coli expressing aptamers was observed for 12-hour period. Our analysis indicated that aptamers helped to increase the intracellular concentration of aminoglycosides thereby increasing their efficacy.

  5. Modeling Cyber Physical War Gaming

    Science.gov (United States)

    2017-08-07

    games share similar constructs. We also provide a game-theoretic approach to mathematically analyze attacker and defender strategies in cyber war...Military Practice of Course-of-Action Analysis 4 2. Game-Theoretic Method 7 2.1 Mathematical Model 7 2.2 Strategy Selection 10 2.2.1 Pure...officers, hundreds of combat and support vehicles, helicopters, sophisticated intelligence and communication equipment and specialists , artillery and

  6. Modern elementary particle physics explaining and extending the standard model

    CERN Document Server

    Kane, Gordon

    2017-01-01

    This book is written for students and scientists wanting to learn about the Standard Model of particle physics. Only an introductory course knowledge about quantum theory is needed. The text provides a pedagogical description of the theory, and incorporates the recent Higgs boson and top quark discoveries. With its clear and engaging style, this new edition retains its essential simplicity. Long and detailed calculations are replaced by simple approximate ones. It includes introductions to accelerators, colliders, and detectors, and several main experimental tests of the Standard Model are explained. Descriptions of some well-motivated extensions of the Standard Model prepare the reader for new developments. It emphasizes the concepts of gauge theories and Higgs physics, electroweak unification and symmetry breaking, and how force strengths vary with energy, providing a solid foundation for those working in the field, and for those who simply want to learn about the Standard Model.

  7. Ladder physics in the spin fermion model

    Science.gov (United States)

    Tsvelik, A. M.

    2017-05-01

    A link is established between the spin fermion (SF) model of the cuprates and the approach based on the analogy between the physics of doped Mott insulators in two dimensions and the physics of fermionic ladders. This enables one to use nonperturbative results derived for fermionic ladders to move beyond the large-N approximation in the SF model. It is shown that the paramagnon exchange postulated in the SF model has exactly the right form to facilitate the emergence of the fully gapped d -Mott state in the region of the Brillouin zone at the hot spots of the Fermi surface. Hence, the SF model provides an adequate description of the pseudogap.

  8. Simulation study of a rectifying bipolar ion channel: Detailed model versus reduced model

    Directory of Open Access Journals (Sweden)

    Z. Ható

    2016-02-01

    Full Text Available We study a rectifying mutant of the OmpF porin ion channel using both all-atom and reduced models. The mutant was created by Miedema et al. [Nano Lett., 2007, 7, 2886] on the basis of the NP semiconductor diode, in which an NP junction is formed. The mutant contains a pore region with positive amino acids on the left-hand side and negative amino acids on the right-hand side. Experiments show that this mutant rectifies. Although we do not know the structure of this mutant, we can build an all-atom model for it on the basis of the structure of the wild type channel. Interestingly, molecular dynamics simulations for this all-atom model do not produce rectification. A reduced model that contains only the important degrees of freedom (the positive and negative amino acids and free ions in an implicit solvent, on the other hand, exhibits rectification. Our calculations for the reduced model (using the Nernst-Planck equation coupled to Local Equilibrium Monte Carlo simulations reveal a rectification mechanism that is different from that seen for semiconductor diodes. The basic reason is that the ions are different in nature from electrons and holes (they do not recombine. We provide explanations for the failure of the all-atom model including the effect of all the other atoms in the system as a noise that inhibits the response of ions (that would be necessary for rectification to the polarizing external field.

  9. A detailed chemical kinetic model for pyrolysis of the lignin model compound chroman

    Directory of Open Access Journals (Sweden)

    James Bland

    2013-12-01

    Full Text Available The pyrolysis of woody biomass, including the lignin component, is emerging as a potential technology for the production of renewable fuels and commodity chemicals. Here we describe the construction and implementation of an elementary chemical kinetic model for pyrolysis of the lignin model compound chroman and its reaction intermediate ortho-quinone methide (o-QM. The model is developed using both experimental and theoretical data, and represents a hybrid approach to kinetic modeling that has the potential to provide molecular level insight into reaction pathways and intermediates while accurately describing reaction rates and product formation. The kinetic model developed here can replicate all known aspects of chroman pyrolysis, and provides new information on elementary reaction steps. Chroman pyrolysis is found to proceed via an initial retro-Diels–Alder reaction to form o-QM + ethene (C2H4, followed by dissociation of o-QM to the C6H6 isomers benzene and fulvene (+ CO. At temperatures of around 1000–1200 K and above fulvene rapidly isomerizes to benzene, where an activation energy of around 270 kJ mol-1 is required to reproduce experimental observations. A new G3SX level energy surface for the isomerization of fulvene to benzene supports this result. Our modeling also suggests that thermal decomposition of fulvene may be important at around 950 K and above. This study demonstrates that theoretical protocols can provide a significant contribution to the development of kinetic models for biomass pyrolysis by elucidating reaction mechanisms, intermediates, and products, and also by supplying realistic rate coefficients and thermochemical properties.

  10. Detailed kinetic and heat transport model for the hydrolysis of lignocellulose by anhydrous hydrogen fluoride vapor

    Energy Technology Data Exchange (ETDEWEB)

    Rorrer, G.L.; Mohring, W.R.; Lamport, D.T.A.; Hawley, M.C.

    1988-01-01

    Anhydrous Hydrogen Fluoride (HF) vapor at ambient conditions efficiently and rapidly hydrolyzed lignocellulose to glucose and lignin. The unsteady-state reaction of HF vapor with a single lignocellulose chip was mathematically modeled under conditions where external and internal mass-transfer resistances were minimized. The model incorporated physical adsorption of HF vapor onto the lignocellulosic matrix and solvolysis of cellulose to glucosyl fluoride by adsorbed HF into the differential material and energy balance expressions. Model predictions for the temperature distribution and global glucose yield in the HF-reacting lignocellulose chip as a function of reaction time and HF vapor stream temperature agreed reasonably with the complimentary experimental data. The model correctly predicted that even when mass-transfer resistances for the reaction of HF vapor with a single lignocellulose chip are minimized, external and internal heat-transfer resistances are still significant.

  11. Ontology modeling in physical asset integrity management

    CERN Document Server

    Yacout, Soumaya

    2015-01-01

    This book presents cutting-edge applications of, and up-to-date research on, ontology engineering techniques in the physical asset integrity domain. Though a survey of state-of-the-art theory and methods on ontology engineering, the authors emphasize essential topics including data integration modeling, knowledge representation, and semantic interpretation. The book also reflects novel topics dealing with the advanced problems of physical asset integrity applications such as heterogeneity, data inconsistency, and interoperability existing in design and utilization. With a distinctive focus on applications relevant in heavy industry, Ontology Modeling in Physical Asset Integrity Management is ideal for practicing industrial and mechanical engineers working in the field, as well as researchers and graduate concerned with ontology engineering in physical systems life cycles. This book also: Introduces practicing engineers, research scientists, and graduate students to ontology engineering as a modeling techniqu...

  12. Dynamic modeling of physical phenomena for PRAs using neural networks

    International Nuclear Information System (INIS)

    Benjamin, A.S.; Brown, N.N.; Paez, T.L.

    1998-04-01

    In most probabilistic risk assessments, there is a set of accident scenarios that involves the physical responses of a system to environmental challenges. Examples include the effects of earthquakes and fires on the operability of a nuclear reactor safety system, the effects of fires and impacts on the safety integrity of a nuclear weapon, and the effects of human intrusions on the transport of radionuclides from an underground waste facility. The physical responses of the system to these challenges can be quite complex, and their evaluation may require the use of detailed computer codes that are very time consuming to execute. Yet, to perform meaningful probabilistic analyses, it is necessary to evaluate the responses for a large number of variations in the input parameters that describe the initial state of the system, the environments to which it is exposed, and the effects of human interaction. Because the uncertainties of the system response may be very large, it may also be necessary to perform these evaluations for various values of modeling parameters that have high uncertainties, such as material stiffnesses, surface emissivities, and ground permeabilities. The authors have been exploring the use of artificial neural networks (ANNs) as a means for estimating the physical responses of complex systems to phenomenological events such as those cited above. These networks are designed as mathematical constructs with adjustable parameters that can be trained so that the results obtained from the networks will simulate the results obtained from the detailed computer codes. The intent is for the networks to provide an adequate simulation of the detailed codes over a significant range of variables while requiring only a small fraction of the computer processing time required by the detailed codes. This enables the authors to integrate the physical response analyses into the probabilistic models in order to estimate the probabilities of various responses

  13. Towards the optimal fusion of high-resolution Digital Elevation Models for detailed urban flood assessment

    Science.gov (United States)

    Leitão, J. P.; de Sousa, L. M.

    2018-06-01

    Newly available, more detailed and accurate elevation data sets, such as Digital Elevation Models (DEMs) generated on the basis of imagery from terrestrial LiDAR (Light Detection and Ranging) systems or Unmanned Aerial Vehicles (UAVs), can be used to improve flood-model input data and consequently increase the accuracy of the flood modelling results. This paper presents the first application of the MBlend merging method and assesses the impact of combining different DEMs on flood modelling results. It was demonstrated that different raster merging methods can have different and substantial impacts on these results. In addition to the influence associated with the method used to merge the original DEMs, the magnitude of the impact also depends on (i) the systematic horizontal and vertical differences of the DEMs, and (ii) the orientation between the DEM boundary and the terrain slope. The greater water depth and flow velocity differences between the flood modelling results obtained using the reference DEM and the merged DEMs ranged from -9.845 to 0.002 m, and from 0.003 to 0.024 m s-1 respectively; these differences can have a significant impact on flood hazard estimates. In most of the cases investigated in this study, the differences from the reference DEM results were smaller for the MBlend method than for the results of the two conventional methods. This study highlighted the importance of DEM merging when conducting flood modelling and provided hints on the best DEM merging methods to use.

  14. Checking the validity of Busquet's ionization temperature with detailed collisional radiative models.

    Science.gov (United States)

    Klapisch, M.; Bar-Shalom, A.

    1997-12-01

    Busquet's RADIOM model for effective ionization temperature Tz is an appealing and simple way to introduce non LTE effects in hydrocodes. The authors report checking the validity of RADIOM in the optically thin case by comparison with two collisional radiative models, MICCRON (level-by-level) for C and Al and SCROLL (superconfiguration- by-superconfiguration) for Lu and Au. MICCRON is described in detail. The agreement between the average ion charge >ZBusquet is very good in most cases. There is however room for improvement when the departure from LTE is more pronounced for heavy atoms and for emissivity. Improvement appears possible because the concept of ionization temperature seems to hold in a broader range of parameters.

  15. KNOW YOUR NEIGHBORHOOD: A DETAILED MODEL ATMOSPHERE ANALYSIS OF NEARBY WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Giammichele, N.; Bergeron, P. [Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation (United States); Dufour, P., E-mail: noemi.giammichele@astro.umontreal.ca, E-mail: pierre.bergeron@astro.umontreal.ca, E-mail: patrick.dufour@astro.umontreal.ca [Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada)

    2012-04-01

    We present improved atmospheric parameters of nearby white dwarfs lying within 20 pc of the Sun. The aim of the current study is to obtain the best statistical model of the least-biased sample of the white dwarf population. A homogeneous analysis of the local population is performed combining detailed spectroscopic and photometric analyses based on improved model atmosphere calculations for various spectral types including DA, DB, DC, DQ, and DZ stars. The spectroscopic technique is applied to all stars in our sample for which optical spectra are available. Photometric energy distributions, when available, are also combined to trigonometric parallax measurements to derive effective temperatures, stellar radii, as well as atmospheric compositions. A revised catalog of white dwarfs in the solar neighborhood is presented. We provide, for the first time, a comprehensive analysis of the mass distribution and the chemical distribution of white dwarf stars in a volume-limited sample.

  16. Modelling Mathematical Reasoning in Physics Education

    Science.gov (United States)

    Uhden, Olaf; Karam, Ricardo; Pietrocola, Maurício; Pospiech, Gesche

    2012-04-01

    Many findings from research as well as reports from teachers describe students' problem solving strategies as manipulation of formulas by rote. The resulting dissatisfaction with quantitative physical textbook problems seems to influence the attitude towards the role of mathematics in physics education in general. Mathematics is often seen as a tool for calculation which hinders a conceptual understanding of physical principles. However, the role of mathematics cannot be reduced to this technical aspect. Hence, instead of putting mathematics away we delve into the nature of physical science to reveal the strong conceptual relationship between mathematics and physics. Moreover, we suggest that, for both prospective teaching and further research, a focus on deeply exploring such interdependency can significantly improve the understanding of physics. To provide a suitable basis, we develop a new model which can be used for analysing different levels of mathematical reasoning within physics. It is also a guideline for shifting the attention from technical to structural mathematical skills while teaching physics. We demonstrate its applicability for analysing physical-mathematical reasoning processes with an example.

  17. Detailed modelling of processes inside a catalytic recombiner for hydrogen removal

    International Nuclear Information System (INIS)

    Heitsch, M.

    1999-01-01

    Under accidental conditions, considerable amounts of hydrogen may be released into the containment. Catalytic reacting surfaces in recombiners are a reliable method to recombine this hydrogen and other burnable gases like carbon monoxide from the atmosphere in a passive way. Many experiments have been carried out to study the main phenomena occurring inside recombiners, like the efficiency of hydrogen removal, the start-up conditions, poisoning, oxygen starvation, steam and water impact, and others. In addition, the global behavior of a given recombiner device in a larger environment has been investigated in order to demonstrate the effectiveness and to facilitate the derivation of simplified models for long term, severe accident analyses. These long-term severe accident models are complemented by detailed investigations to understand the interaction of chemistry and flow inside a recombiner box. This helps to provide the dependencies of non-measurable variables (e.g. the reaction rate distribution), of local surface temperatures etc. to make long-term or system models more reliable. It also offers possibilities for increasing the chemical efficiency by optimising the geometric design properly. Computational Fluid Dynamics (CFD) codes are available for use as development tools to include the specifics of catalytic surface reactors. The present paper describes the use of the code system CFX [1] for creating a recombiner model. Some model predictions are compared to existing test data. (author)

  18. Detailed H2 and CO Electrochemistry for a MEA Model Fueled by Syngas

    KAUST Repository

    Lee, W. Y.

    2015-07-17

    © The Electrochemical Society. SOFCs can directly oxidize CO in addition to H2, which allows them to be coupled to a gasifier. Many membrane-electrode-assembly (MEA) models neglect CO electrochemistry due to sluggish kinetics and the water-gas-shift reaction, but CO oxidation may be important for high CO-content syngas. The 1D-MEA model presented here incorporates detailed mechanisms for both H2 and CO oxidation, individually fitted to experimental data. These mechanisms are then combined into a single model, which provides a good fit to experimental data for H2/CO mixtures. Furthermore, the model fits H2/CO data best when a single chargetransfer step in the H2 mechanism is assumed to be rate-limiting for all current densities. This differs from the result for H2/H2O mixtures, where H2 adsorption becomes rate-limiting at high current densities. These results indicate that CO oxidation cannot be neglected in MEA models running on CO-rich syngas, and that CO oxidation can alter the H2 oxidation mechanism.

  19. Development of steady-state model for MSPT and detailed analyses of receiver

    Science.gov (United States)

    Yuasa, Minoru; Sonoda, Masanori; Hino, Koichi

    2016-05-01

    Molten salt parabolic trough system (MSPT) uses molten salt as heat transfer fluid (HTF) instead of synthetic oil. The demonstration plant of MSPT was constructed by Chiyoda Corporation and Archimede Solar Energy in Italy in 2013. Chiyoda Corporation developed a steady-state model for predicting the theoretical behavior of the demonstration plant. The model was designed to calculate the concentrated solar power and heat loss using ray tracing of incident solar light and finite element modeling of thermal energy transferred into the medium. This report describes the verification of the model using test data on the demonstration plant, detailed analyses on the relation between flow rate and temperature difference on the metal tube of receiver and the effect of defocus angle on concentrated power rate, for solar collector assembly (SCA) development. The model is accurate to an extent of 2.0% as systematic error and 4.2% as random error. The relationships between flow rate and temperature difference on metal tube and the effect of defocus angle on concentrated power rate are shown.

  20. A detailed aerosol mixing state model for investigating interactions between mixing state, semivolatile partitioning, and coagulation

    Directory of Open Access Journals (Sweden)

    J. Lu

    2010-04-01

    Full Text Available A new method for describing externally mixed particles, the Detailed Aerosol Mixing State (DAMS representation, is presented in this study. This novel method classifies aerosols by both composition and size, using a user-specified mixing criterion to define boundaries between compositional populations. Interactions between aerosol mixing state, semivolatile partitioning, and coagulation are investigated with a Lagrangian box model that incorporates the DAMS approach. Model results predict that mixing state affects the amount and types of semivolatile organics that partition to available aerosol phases, causing external mixtures to produce a more size-varying composition than internal mixtures. Both coagulation and condensation contribute to the mixing of emitted particles, producing a collection of multiple compositionally distinct aerosol populations that exists somewhere between the extremes of a strictly external or internal mixture. The selection of mixing criteria has a significant impact on the size and type of individual populations that compose the modeled aerosol mixture. Computational demands for external mixture modeling are significant and can be controlled by limiting the number of aerosol populations used in the model.

  1. Utilities for high performance dispersion model PHYSIC

    International Nuclear Information System (INIS)

    Yamazawa, Hiromi

    1992-09-01

    The description and usage of the utilities for the dispersion calculation model PHYSIC were summarized. The model was developed in the study of developing high performance SPEEDI with the purpose of introducing meteorological forecast function into the environmental emergency response system. The procedure of PHYSIC calculation consists of three steps; preparation of relevant files, creation and submission of JCL, and graphic output of results. A user can carry out the above procedure with the help of the Geographical Data Processing Utility, the Model Control Utility, and the Graphic Output Utility. (author)

  2. Waste Feed Evaporation Physical Properties Modeling

    International Nuclear Information System (INIS)

    Daniel, W.E.

    2003-01-01

    This document describes the waste feed evaporator modeling work done in the Waste Feed Evaporation and Physical Properties Modeling test specification and in support of the Hanford River Protection Project (RPP) Waste Treatment Plant (WTP) project. A private database (ZEOLITE) was developed and used in this work in order to include the behavior of aluminosilicates such a NAS-gel in the OLI/ESP simulations, in addition to the development of the mathematical models. Mathematical models were developed that describe certain physical properties in the Hanford RPP-WTP waste feed evaporator process (FEP). In particular, models were developed for the feed stream to the first ultra-filtration step characterizing its heat capacity, thermal conductivity, and viscosity, as well as the density of the evaporator contents. The scope of the task was expanded to include the volume reduction factor across the waste feed evaporator (total evaporator feed volume/evaporator bottoms volume). All the physical properties were modeled as functions of the waste feed composition, temperature, and the high level waste recycle volumetric flow rate relative to that of the waste feed. The goal for the mathematical models was to predict the physical property to predicted simulation value. The simulation model approximating the FEP process used to develop the correlations was relatively complex, and not possible to duplicate within the scope of the bench scale evaporation experiments. Therefore, simulants were made of 13 design points (a subset of the points used in the model fits) using the compositions of the ultra-filtration feed streams as predicted by the simulation model. The chemistry and physical properties of the supernate (the modeled stream) as predicted by the simulation were compared with the analytical results of experimental simulant work as a method of validating the simulation software

  3. A study on the intrusion model by physical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Yul; Kim, Yoo Sung; Hyun, Hye Ja [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    In physical modeling, the actual phenomena of seismic wave propagation are directly measured like field survey and furthermore the structure and physical properties of subsurface can be known. So the measured datasets from physical modeling can be very desirable as input data to test the efficiency of various inversion algorithms. An underground structure formed by intrusion, which can be often seen in seismic section for oil exploration, is investigated by physical modeling. The model is characterized by various types of layer boundaries with steep dip angle. Therefore, this physical modeling data are very available not only to interpret seismic sections for oil exploration as a case history, but also to develop data processing techniques and estimate the capability of software such as migration, full waveform inversion. (author). 5 refs., 18 figs.

  4. The use of physical model simulation to emulate an AGV material handling system

    International Nuclear Information System (INIS)

    Hurley, R.G.; Coffman, P.E.; Dixon, J.R.; Walacavage, J.G.

    1987-01-01

    This paper describes an application of physical modeling to the simulation of a prototype AGV (Automatic Guided Vehicle) material handling system. Physical modeling is the study of complex automated manufacturing and material handling systems through the use of small scale components controlled by mini and/or microcomputers. By modeling the mechanical operations of the proposed AGV material handling system, it was determined that control algorithms and AGV dispatch rules could be developed and evaluated. This paper presents a brief explanation of physical modeling as a simulation tool and addresses in detail the development of the control algorithm, dispatching rules, and a prototype physical model of a flexible machining system

  5. Plasma simulation studies using multilevel physics models

    International Nuclear Information System (INIS)

    Park, W.; Belova, E.V.; Fu, G.Y.; Tang, X.Z.; Strauss, H.R.; Sugiyama, L.E.

    1999-01-01

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of δf particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future. copyright 1999 American Institute of Physics

  6. Implications of Model Structure and Detail for Utility Planning: Scenario Case Studies Using the Resource Planning Model

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barrows, Clayton [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hale, Elaine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dyson, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eurek, Kelly [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-04-01

    In this report, we analyze the impacts of model configuration and detail in capacity expansion models, computational tools used by utility planners looking to find the least cost option for planning the system and by researchers or policy makers attempting to understand the effects of various policy implementations. The present analysis focuses on the importance of model configurations — particularly those related to capacity credit, dispatch modeling, and transmission modeling — to the construction of scenario futures. Our analysis is primarily directed toward advanced tools used for utility planning and is focused on those impacts that are most relevant to decisions with respect to future renewable capacity deployment. To serve this purpose, we develop and employ the NREL Resource Planning Model to conduct a case study analysis that explores 12 separate capacity expansion scenarios of the Western Interconnection through 2030.

  7. Physically realistic modeling of maritime training simulation

    OpenAIRE

    Cieutat , Jean-Marc

    2003-01-01

    Maritime training simulation is an important matter of maritime teaching, which requires a lot of scientific and technical skills.In this framework, where the real time constraint has to be maintained, all physical phenomena cannot be studied; the most visual physical phenomena relating to the natural elements and the ship behaviour are reproduced only. Our swell model, based on a surface wave simulation approach, permits to simulate the shape and the propagation of a regular train of waves f...

  8. Investigation of whiplash injuries in the upper cervical spine using a detailed neck model.

    Science.gov (United States)

    Fice, Jason B; Cronin, Duane S

    2012-04-05

    Whiplash injuries continue to have significant societal cost; however, the mechanism and location of whiplash injury is still under investigation. Recently, the upper cervical spine ligaments, particularly the alar ligament, have been identified as a potential whiplash injury location. In this study, a detailed and validated explicit finite element model of a 50th percentile male cervical spine in a seated posture was used to investigate upper cervical spine response and the potential for whiplash injury resulting from vehicle crash scenarios. This model was previously validated at the segment and whole spine levels for both kinematics and soft tissue strains in frontal and rear impact scenarios. The model predicted increasing upper cervical spine ligament strain with increasing impact severity. Considering all upper cervical spine ligaments, the distractions in the apical and alar ligaments were the largest relative to their failure strains, in agreement with the clinical findings. The model predicted the potential for injury to the apical ligament for 15.2 g frontal or 11.7 g rear impacts, and to the alar ligament for a 20.7 g frontal or 14.4 g rear impact based on the ligament distractions. Future studies should consider the effect of initial occupant position on ligament distraction. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. A DETAILED SPATIOKINEMATIC MODEL OF THE CONICAL OUTFLOW OF THE MULTIPOLAR PLANETARY NEBULA NGC 7026

    International Nuclear Information System (INIS)

    Clark, D. M.; López, J. A.; Steffen, W.; Richer, M. G.

    2013-01-01

    We present extensive, long-slit, high-resolution coverage of the complex planetary nebula (PN) NGC 7026. We acquired 10 spectra using the Manchester Echelle Spectrometer at San Pedro Martir Observatory in Baja California, Mexico, and each shows exquisite detail, revealing the intricate structure of this object. Incorporating these spectra into the three-dimensional visualization and kinematic program SHAPE and using Hubble Space Telescope images of NGC 7026, we have produced a detailed structural and kinematic model of this PN. NGC 7026 exhibits remarkable symmetry consisting of three lobe pairs and four sets of knots, all symmetrical about the nucleus and displaying a conical outflow. Comparing the three-dimensional structure of this nebula to recent XMM-Newton X-ray observations, we investigate the extended X-ray emission in relation to the nebular structure. We find that the X-ray emission, while confined to the closed, northern lobes of this PN, shows an abrupt termination in the middle of the southeast lobe, which our long slit data show to be open. This is where the shocked fast wind seems to be escaping the interior of the nebula and the X-ray emission rapidly cools in this region.

  10. Computational models in physics teaching: a framework

    Directory of Open Access Journals (Sweden)

    Marco Antonio Moreira

    2012-08-01

    Full Text Available The purpose of the present paper is to present a theoretical framework to promote and assist meaningful physics learning through computational models. Our proposal is based on the use of a tool, the AVM diagram, to design educational activities involving modeling and computer simulations. The idea is to provide a starting point for the construction and implementation of didactical approaches grounded in a coherent epistemological view about scientific modeling.

  11. Comparative study between single core model and detail core model of CFD modelling on reactor core cooling behaviour

    Science.gov (United States)

    Darmawan, R.

    2018-01-01

    Nuclear power industry is facing uncertainties since the occurrence of the unfortunate accident at Fukushima Daiichi Nuclear Power Plant. The issue of nuclear power plant safety becomes the major hindrance in the planning of nuclear power program for new build countries. Thus, the understanding of the behaviour of reactor system is very important to ensure the continuous development and improvement on reactor safety. Throughout the development of nuclear reactor technology, investigation and analysis on reactor safety have gone through several phases. In the early days, analytical and experimental methods were employed. For the last four decades 1D system level codes were widely used. The continuous development of nuclear reactor technology has brought about more complex system and processes of nuclear reactor operation. More detailed dimensional simulation codes are needed to assess these new reactors. Recently, 2D and 3D system level codes such as CFD are being explored. This paper discusses a comparative study on two different approaches of CFD modelling on reactor core cooling behaviour.

  12. Simplified Models for LHC New Physics Searches

    International Nuclear Information System (INIS)

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R. Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto

    2012-01-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ∼ 50-500 pb -1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  13. Simplified Models for LHC New Physics Searches

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Daniele; /SLAC; Arkani-Hamed, Nima; /Princeton, Inst. Advanced Study; Arora, Sanjay; /Rutgers U., Piscataway; Bai, Yang; /SLAC; Baumgart, Matthew; /Johns Hopkins U.; Berger, Joshua; /Cornell U., Phys. Dept.; Buckley, Matthew; /Fermilab; Butler, Bart; /SLAC; Chang, Spencer; /Oregon U. /UC, Davis; Cheng, Hsin-Chia; /UC, Davis; Cheung, Clifford; /UC, Berkeley; Chivukula, R.Sekhar; /Michigan State U.; Cho, Won Sang; /Tokyo U.; Cotta, Randy; /SLAC; D' Alfonso, Mariarosaria; /UC, Santa Barbara; El Hedri, Sonia; /SLAC; Essig, Rouven, (ed.); /SLAC; Evans, Jared A.; /UC, Davis; Fitzpatrick, Liam; /Boston U.; Fox, Patrick; /Fermilab; Franceschini, Roberto; /LPHE, Lausanne /Pittsburgh U. /Argonne /Northwestern U. /Rutgers U., Piscataway /Rutgers U., Piscataway /Carleton U. /CERN /UC, Davis /Wisconsin U., Madison /SLAC /SLAC /SLAC /Rutgers U., Piscataway /Syracuse U. /SLAC /SLAC /Boston U. /Rutgers U., Piscataway /Seoul Natl. U. /Tohoku U. /UC, Santa Barbara /Korea Inst. Advanced Study, Seoul /Harvard U., Phys. Dept. /Michigan U. /Wisconsin U., Madison /Princeton U. /UC, Santa Barbara /Wisconsin U., Madison /Michigan U. /UC, Davis /SUNY, Stony Brook /TRIUMF; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  14. PHYSICAL EDUCATION - PHYSICAL CULTURE. TWO MODELS, TWO DIDACTIC

    Directory of Open Access Journals (Sweden)

    Manuel Vizuete Carrizosa

    2014-11-01

    The survival of these conflicting positions and their interests and different views on education, in a lengthy space of time, as a consequence threw two teaching approaches and two different educational models, in which the objectives and content of education differ , and with them the forms and methods of teaching. The need to define the cultural and educational approach, in every time and place, is now a pressing need and challenge the processes of teacher training, as responsible for shaping an advanced physical education, adjusted to the time and place, the interests and needs of citizens and the democratic values of modern society.

  15. Author Details

    African Journals Online (AJOL)

    Samuel, TM. Vol 6, No 2 (2006) - Articles Model Development for Economic Replacement of Equipment in a Depressed Economy Abstract · Vol 8 (2008) - Articles Comparison of physical workload in four Gari-frying working postures in Nigeria Abstract · Vol 8 (2008) - Articles Preliminary study of the ergonomics of Gari frying

  16. Composing Models of Geographic Physical Processes

    Science.gov (United States)

    Hofer, Barbara; Frank, Andrew U.

    Processes are central for geographic information science; yet geographic information systems (GIS) lack capabilities to represent process related information. A prerequisite to including processes in GIS software is a general method to describe geographic processes independently of application disciplines. This paper presents such a method, namely a process description language. The vocabulary of the process description language is derived formally from mathematical models. Physical processes in geography can be described in two equivalent languages: partial differential equations or partial difference equations, where the latter can be shown graphically and used as a method for application specialists to enter their process models. The vocabulary of the process description language comprises components for describing the general behavior of prototypical geographic physical processes. These process components can be composed by basic models of geographic physical processes, which is shown by means of an example.

  17. Global detailed gravimetric geoid. [based on gravity model derived from satellite tracking and surface gravity data

    Science.gov (United States)

    Vincent, S.; Marsh, J. G.

    1973-01-01

    A global detailed gravimetric geoid has been computed by combining the Goddard Space Flight Center GEM-4 gravity model derived from satellite and surface gravity data and surface 1 deg-by-1 deg mean free air gravity anomaly data. The accuracy of the geoid is + or - 2 meters on continents, 5 to 7 meters in areas where surface gravity data are sparse, and 10 to 15 meters in areas where no surface gravity data are available. Comparisons have been made with the astrogeodetic data provided by Rice (United States), Bomford (Europe), and Mather (Australia). Comparisons have also been carried out with geoid heights derived from satellite solutions for geocentric station coordinates in North America, the Caribbean, Europe, and Australia.

  18. Validation of detailed thermal hydraulic models used for LMR safety and for improvement of technical specifications

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, F.E.

    1995-12-31

    Detailed steady-state and transient coolant temperatures and flow rates from an operating reactor have been used to validate the multiple pin model in the SASSYS-1 liquid metal reactor systems analysis code. This multiple pin capability can be used for explicit calculations of axial and lateral temperature distributions within individual subassemblies. Thermocouples at a number of axial locations and in a number of different coolant sub-channels m the XXO9 instrumented subassembly in the EBR-II reactor provided temperature data from the Shutdown Heat Removal Test (SHRT) series. Flow meter data for XXO9 and for the overall system are also available from these tests. Results of consistent SASSYS-1 multiple pin analyses for both the SHRT-45 loss-of-flow-without-scram-test and the S14RT-17 protected loss-of-flow test agree well with the experimental data, providing validation of the SASSYS-1 code over a wide range of conditions.

  19. Operational Details of the Five Domains Model and Its Key Applications to the Assessment and Management of Animal Welfare

    Science.gov (United States)

    Mellor, David J.

    2017-01-01

    Simple Summary The Five Domains Model is a focusing device to facilitate systematic, structured, comprehensive and coherent assessment of animal welfare; it is not a definition of animal welfare, nor is it intended to be an accurate representation of body structure and function. The purpose of each of the five domains is to draw attention to areas that are relevant to both animal welfare assessment and management. This paper begins by briefly describing the major features of the Model and the operational interactions between the five domains, and then it details seven interacting applications of the Model. These underlie its utility and increasing application to welfare assessment and management in diverse animal use sectors. Abstract In accord with contemporary animal welfare science understanding, the Five Domains Model has a significant focus on subjective experiences, known as affects, which collectively contribute to an animal’s overall welfare state. Operationally, the focus of the Model is on the presence or absence of various internal physical/functional states and external circumstances that give rise to welfare-relevant negative and/or positive mental experiences, i.e., affects. The internal states and external circumstances of animals are evaluated systematically by referring to each of the first four domains of the Model, designated “Nutrition”, “Environment”, “Health” and “Behaviour”. Then affects, considered carefully and cautiously to be generated by factors in these domains, are accumulated into the fifth domain, designated “Mental State”. The scientific foundations of this operational procedure, published in detail elsewhere, are described briefly here, and then seven key ways the Model may be applied to the assessment and management of animal welfare are considered. These applications have the following beneficial objectives—they (1) specify key general foci for animal welfare management; (2) highlight the foundations of

  20. PHYSICAL EDUCATION - PHYSICAL CULTURE. TWO MODELS, TWO DIDACTIC

    Directory of Open Access Journals (Sweden)

    Manuel Vizuete Carrizosa

    2014-10-01

    Full Text Available Physical Education is currently facing a number of problems that are rooted in the identity crisis prompted by the spread of the professional group, the confrontation of ideas from the scientific community and the competing interests of different political and social areas, compared to which physical education has failed, or unable, to react in time. The political and ideological confrontation that characterized the twentieth century gave us two forms, each with a consistent ideological position, in which the body as a subject of education was understood from two different positions: one set from the left and communism and another, from Western democratic societies.The survival of these conflicting positions and their interests and different views on education, in a lengthy space of time, as a consequence threw two teaching approaches and two different educational models, in which the objectives and content of education differ , and with them the forms and methods of teaching. The need to define the cultural and educational approach, in every time and place, is now a pressing need and challenge the processes of teacher training, as responsible for shaping an advanced physical education, adjusted to the time and place, the interests and needs of citizens and the democratic values of modern society.

  1. Detailed Modeling and Irreversible Transfer Process Analysis of a Multi-Element Thermoelectric Generator System

    Science.gov (United States)

    Xiao, Heng; Gou, Xiaolong; Yang, Suwen

    2011-05-01

    Thermoelectric (TE) power generation technology, due to its several advantages, is becoming a noteworthy research direction. Many researchers conduct their performance analysis and optimization of TE devices and related applications based on the generalized thermoelectric energy balance equations. These generalized TE equations involve the internal irreversibility of Joule heating inside the thermoelectric device and heat leakage through the thermoelectric couple leg. However, it is assumed that the thermoelectric generator (TEG) is thermally isolated from the surroundings except for the heat flows at the cold and hot junctions. Since the thermoelectric generator is a multi-element device in practice, being composed of many fundamental TE couple legs, the effect of heat transfer between the TE couple leg and the ambient environment is not negligible. In this paper, based on basic theories of thermoelectric power generation and thermal science, detailed modeling of a thermoelectric generator taking account of the phenomenon of energy loss from the TE couple leg is reported. The revised generalized thermoelectric energy balance equations considering the effect of heat transfer between the TE couple leg and the ambient environment have been derived. Furthermore, characteristics of a multi-element thermoelectric generator with irreversibility have been investigated on the basis of the new derived TE equations. In the present investigation, second-law-based thermodynamic analysis (exergy analysis) has been applied to the irreversible heat transfer process in particular. It is found that the existence of the irreversible heat convection process causes a large loss of heat exergy in the TEG system, and using thermoelectric generators for low-grade waste heat recovery has promising potential. The results of irreversibility analysis, especially irreversible effects on generator system performance, based on the system model established in detail have guiding significance for

  2. The optical model in atomic physics

    International Nuclear Information System (INIS)

    McCarthy, I.E.

    1978-01-01

    The optical model for electron scattering on atoms has quite a short history in comparison with nuclear physics. The main reason for this is that there were insufficient data. Angular distribution for elastic and some inelastic scattering have now been measured for the atoms which exist in gaseous form at reasonable temperatures, inert gases, hydrogen, alkalies and mercury being the main ones out in. The author shows that the optical model makes sense in atomic physics by considering its theory and recent history. (orig./AH) [de

  3. Plasma simulation studies using multilevel physics models

    International Nuclear Information System (INIS)

    Park, W.; Belova, E.V.; Fu, G.Y.

    2000-01-01

    The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future

  4. A validated physical model of greenhouse climate

    International Nuclear Information System (INIS)

    Bot, G.P.A.

    1989-01-01

    In the greenhouse model the momentaneous environmental crop growth factors are calculated as output, together with the physical behaviour of the crop. The boundary conditions for this model are the outside weather conditions; other inputs are the physical characteristics of the crop, of the greenhouse and of the control system. The greenhouse model is based on the energy, water vapour and CO 2 balances of the crop-greenhouse system. While the emphasis is on the dynamic behaviour of the greenhouse for implementation in continuous optimization, the state variables temperature, water vapour pressure and carbondioxide concentration in the relevant greenhouse parts crop, air, soil and cover are calculated from the balances over these parts. To do this in a proper way, the physical exchange processes between the system parts have to be quantified first. Therefore the greenhouse model is constructed from submodels describing these processes: a. Radiation transmission model for the modification of the outside to the inside global radiation. b. Ventilation model to describe the ventilation exchange between greenhouse and outside air. c. The description of the exchange of energy and mass between the crop and the greenhouse air. d. Calculation of the thermal radiation exchange between the various greenhouse parts. e. Quantification of the convective exchange processes between the greenhouse air and respectively the cover, the heating pipes and the soil surface and between the cover and the outside air. f. Determination of the heat conduction in the soil. The various submodels are validated first and then the complete greenhouse model is verified

  5. Topos models for physics and topos theory

    International Nuclear Information System (INIS)

    Wolters, Sander

    2014-01-01

    What is the role of topos theory in the topos models for quantum theory as used by Isham, Butterfield, Döring, Heunen, Landsman, Spitters, and others? In other words, what is the interplay between physical motivation for the models and the mathematical framework used in these models? Concretely, we show that the presheaf topos model of Butterfield, Isham, and Döring resembles classical physics when viewed from the internal language of the presheaf topos, similar to the copresheaf topos model of Heunen, Landsman, and Spitters. Both the presheaf and copresheaf models provide a “quantum logic” in the form of a complete Heyting algebra. Although these algebras are natural from a topos theoretic stance, we seek a physical interpretation for the logical operations. Finally, we investigate dynamics. In particular, we describe how an automorphism on the operator algebra induces a homeomorphism (or isomorphism of locales) on the associated state spaces of the topos models, and how elementary propositions and truth values transform under the action of this homeomorphism. Also with dynamics the focus is on the internal perspective of the topos

  6. Ladder physics in the spin fermion model

    International Nuclear Information System (INIS)

    Tsvelik, A. M.

    2017-01-01

    A link is established between the spin fermion (SF) model of the cuprates and the approach based on the analogy between the physics of doped Mott insulators in two dimensions and the physics of fermionic ladders. This enables one to use nonperturbative results derived for fermionic ladders to move beyond the large-N approximation in the SF model. Here, it is shown that the paramagnon exchange postulated in the SF model has exactly the right form to facilitate the emergence of the fully gapped d-Mott state in the region of the Brillouin zone at the hot spots of the Fermi surface. Hence, the SF model provides an adequate description of the pseudogap.

  7. Statistical physics of pairwise probability models

    DEFF Research Database (Denmark)

    Roudi, Yasser; Aurell, Erik; Hertz, John

    2009-01-01

    (dansk abstrakt findes ikke) Statistical models for describing the probability distribution over the states of biological systems are commonly used for dimensional reduction. Among these models, pairwise models are very attractive in part because they can be fit using a reasonable amount of  data......: knowledge of the means and correlations between pairs of elements in the system is sufficient. Not surprisingly, then, using pairwise models for studying neural data has been the focus of many studies in recent years. In this paper, we describe how tools from statistical physics can be employed for studying...

  8. CFD analysis of municipal solid waste combustion using detailed chemical kinetic modelling.

    Science.gov (United States)

    Frank, Alex; Castaldi, Marco J

    2014-08-01

    Nitrogen oxides (NO x ) emissions from the combustion of municipal solid waste (MSW) in waste-to-energy (WtE) facilities are receiving renewed attention to reduce their output further. While NO x emissions are currently 60% below allowed limits, further reductions will decrease the air pollution control (APC) system burden and reduce consumption of NH3. This work combines the incorporation of the GRI 3.0 mechanism as a detailed chemical kinetic model (DCKM) into a custom three-dimensional (3D) computational fluid dynamics (CFD) model fully to understand the NO x chemistry in the above-bed burnout zones. Specifically, thermal, prompt and fuel NO formation mechanisms were evaluated for the system and a parametric study was utilized to determine the effect of varying fuel nitrogen conversion intermediates between HCN, NH3 and NO directly. Simulation results indicate that the fuel nitrogen mechanism accounts for 92% of the total NO produced in the system with thermal and prompt mechanisms accounting for the remaining 8%. Results also show a 5% variation in final NO concentration between HCN and NH3 inlet conditions, demonstrating that the fuel nitrogen intermediate assumed is not significant. Furthermore, the conversion ratio of fuel nitrogen to NO was 0.33, revealing that the majority of fuel nitrogen forms N2. © The Author(s) 2014.

  9. Mathematical and physical models and radiobiology

    International Nuclear Information System (INIS)

    Lokajicek, M.

    1980-01-01

    The hit theory of the mechanism of biological radiation effects in the cell is discussed with respect to radiotherapy. The mechanisms of biological effects and of intracellular recovery, the cumulative radiation effect and the cumulative biological effect in fractionated irradiation are described. The benefit is shown of consistent application of mathematical and physical models in radiobiology and radiotherapy. (J.P.)

  10. Protein Folding: Search for Basic Physical Models

    Directory of Open Access Journals (Sweden)

    Ivan Y. Torshin

    2003-01-01

    Full Text Available How a unique three-dimensional structure is rapidly formed from the linear sequence of a polypeptide is one of the important questions in contemporary science. Apart from biological context of in vivo protein folding (which has been studied only for a few proteins, the roles of the fundamental physical forces in the in vitro folding remain largely unstudied. Despite a degree of success in using descriptions based on statistical and/or thermodynamic approaches, few of the current models explicitly include more basic physical forces (such as electrostatics and Van Der Waals forces. Moreover, the present-day models rarely take into account that the protein folding is, essentially, a rapid process that produces a highly specific architecture. This review considers several physical models that may provide more direct links between sequence and tertiary structure in terms of the physical forces. In particular, elaboration of such simple models is likely to produce extremely effective computational techniques with value for modern genomics.

  11. Dilution physics modeling: Dissolution/precipitation chemistry

    International Nuclear Information System (INIS)

    Onishi, Y.; Reid, H.C.; Trent, D.S.

    1995-09-01

    This report documents progress made to date on integrating dilution/precipitation chemistry and new physical models into the TEMPEST thermal-hydraulics computer code. Implementation of dissolution/precipitation chemistry models is necessary for predicting nonhomogeneous, time-dependent, physical/chemical behavior of tank wastes with and without a variety of possible engineered remediation and mitigation activities. Such behavior includes chemical reactions, gas retention, solids resuspension, solids dissolution and generation, solids settling/rising, and convective motion of physical and chemical species. Thus this model development is important from the standpoint of predicting the consequences of various engineered activities, such as mitigation by dilution, retrieval, or pretreatment, that can affect safe operations. The integration of a dissolution/precipitation chemistry module allows the various phase species concentrations to enter into the physical calculations that affect the TEMPEST hydrodynamic flow calculations. The yield strength model of non-Newtonian sludge correlates yield to a power function of solids concentration. Likewise, shear stress is concentration-dependent, and the dissolution/precipitation chemistry calculations develop the species concentration evolution that produces fluid flow resistance changes. Dilution of waste with pure water, molar concentrations of sodium hydroxide, and other chemical streams can be analyzed for the reactive species changes and hydrodynamic flow characteristics

  12. Physical and mathematical modelling of extrusion processes

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Gronostajski, Z.; Niechajowics, A.

    2000-01-01

    The main objective of the work is to study the extrusion process using physical modelling and to compare the findings of the study with finite element predictions. The possibilities and advantages of the simultaneous application of both of these methods for the analysis of metal forming processes...

  13. Physical models for classroom teaching in hydrology

    Directory of Open Access Journals (Sweden)

    A. Rodhe

    2012-09-01

    Full Text Available Hydrology teaching benefits from the fact that many important processes can be illustrated and explained with simple physical models. A set of mobile physical models has been developed and used during many years of lecturing at basic university level teaching in hydrology. One model, with which many phenomena can be demonstrated, consists of a 1.0-m-long plexiglass container containing an about 0.25-m-deep open sand aquifer through which water is circulated. The model can be used for showing the groundwater table and its influence on the water content in the unsaturated zone and for quantitative determination of hydraulic properties such as the storage coefficient and the saturated hydraulic conductivity. It is also well suited for discussions on the runoff process and the significance of recharge and discharge areas for groundwater. The flow paths of water and contaminant dispersion can be illustrated in tracer experiments using fluorescent or colour dye. This and a few other physical models, with suggested demonstrations and experiments, are described in this article. The finding from using models in classroom teaching is that it creates curiosity among the students, promotes discussions and most likely deepens the understanding of the basic processes.

  14. Service Learning In Physics: The Consultant Model

    Science.gov (United States)

    Guerra, David

    2005-04-01

    Each year thousands of students across the country and across the academic disciplines participate in service learning. Unfortunately, with no clear model for integrating community service into the physics curriculum, there are very few physics students engaged in service learning. To overcome this shortfall, a consultant based service-learning program has been developed and successfully implemented at Saint Anselm College (SAC). As consultants, students in upper level physics courses apply their problem solving skills in the service of others. Most recently, SAC students provided technical and managerial support to a group from Girl's Inc., a national empowerment program for girls in high-risk, underserved areas, who were participating in the national FIRST Lego League Robotics competition. In their role as consultants the SAC students provided technical information through brainstorming sessions and helped the girls stay on task with project management techniques, like milestone charting. This consultant model of service-learning, provides technical support to groups that may not have a great deal of resources and gives physics students a way to improve their interpersonal skills, test their technical expertise, and better define the marketable skill set they are developing through the physics curriculum.

  15. Structure and physical properties of bio membranes and model membranes

    International Nuclear Information System (INIS)

    Tibor Hianik

    2006-01-01

    Bio membranes belong to the most important structures of the cell and the cell organelles. They play not only structural role of the barrier separating the external and internal part of the membrane but contain also various functional molecules, like receptors, ionic channels, carriers and enzymes. The cell membrane also preserves non-equilibrium state in a cell which is crucial for maintaining its excitability and other signaling functions. The growing interest to the bio membranes is also due to their unique physical properties. From physical point of view the bio membranes, that are composed of lipid bilayer into which are incorporated integral proteins and on their surface are anchored peripheral proteins and polysaccharides, represent liquid s crystal of smectic type. The bio membranes are characterized by anisotropy of structural and physical properties. The complex structure of bio membranes makes the study of their physical properties rather difficult. Therefore several model systems that mimic the structure of bio membranes were developed. Among them the lipid monolayers at an air-water interphase, bilayer lipid membranes, supported bilayer lipid membranes and liposomes are most known. This work is focused on the introduction into the physical word of the bio membranes and their models. After introduction to the membrane structure and the history of its establishment, the physical properties of the bio membranes and their models are stepwise presented. The most focus is on the properties of lipid monolayers, bilayer lipid membranes, supported bilayer lipid membranes and liposomes that were most detailed studied. This lecture has tutorial character that may be useful for undergraduate and graduate students in the area of biophysics, biochemistry, molecular biology and bioengineering, however it contains also original work of the author and his co-worker and PhD students, that may be useful also for specialists working in the field of bio membranes and model

  16. Modelling the physics in iterative reconstruction for transmission computed tomography

    Science.gov (United States)

    Nuyts, Johan; De Man, Bruno; Fessler, Jeffrey A.; Zbijewski, Wojciech; Beekman, Freek J.

    2013-01-01

    There is an increasing interest in iterative reconstruction (IR) as a key tool to improve quality and increase applicability of X-ray CT imaging. IR has the ability to significantly reduce patient dose, it provides the flexibility to reconstruct images from arbitrary X-ray system geometries and it allows to include detailed models of photon transport and detection physics, to accurately correct for a wide variety of image degrading effects. This paper reviews discretisation issues and modelling of finite spatial resolution, Compton scatter in the scanned object, data noise and the energy spectrum. Widespread implementation of IR with highly accurate model-based correction, however, still requires significant effort. In addition, new hardware will provide new opportunities and challenges to improve CT with new modelling. PMID:23739261

  17. Condensing a detailed groundwater flow and contaminant transport model into a geosphere model for environmental and safety assessment

    International Nuclear Information System (INIS)

    Chan Tin; Melnyk, Ted

    2004-01-01

    AECL (Atomic Energy of Canada Limited) is preparing an Environmental Impact Statement (EIS) to present its case to a federal environmental assessment panel for a concept for disposal of Canada's nuclear fuel waste. The concept is that of a sealed vault constructed at a depth of 500 to 1,000 m in plutonic rock of the Canadian Shield. An analysis of disposal system performance using a probabilistic system variability analysis code (SYVAC3-CC3) has been an important component of the assessment of the long-term safety and environmental impacts of the disposal system. In the assessment, the disposal system is divided into vault, geosphere and biosphere, each of which is represented by a computationally simplified model. This paper summarizes the procedure for condensing a detailed 3-D finite-element hydrogeological model into the SYVAC3-CC3 geosphere model, GEONET. (author)

  18. Nuclear physics for applications. A model approach

    International Nuclear Information System (INIS)

    Prussin, S.G.

    2007-01-01

    Written by a researcher and teacher with experience at top institutes in the US and Europe, this textbook provides advanced undergraduates minoring in physics with working knowledge of the principles of nuclear physics. Simplifying models and approaches reveal the essence of the principles involved, with the mathematical and quantum mechanical background integrated in the text where it is needed and not relegated to the appendices. The practicality of the book is enhanced by numerous end-of-chapter problems and solutions available on the Wiley homepage. (orig.)

  19. Detailed assessment of diesel spray atomization models using visible and X-ray extinction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Magnotti, G.M.; Genzale, C.L. (GIT)

    2017-12-01

    The physical mechanisms characterizing the breakup of a diesel spray into droplets are still unknown. This gap in knowledge has largely been due to the challenges of directly imaging this process or quantitatively measuring the outcomes of spray breakup, such as droplet size. Recent x-ray measurements by Argonne National Laboratory, utilized in this work, provide needed information about the spatial evolution of droplet sizes in selected regions of the spray under a range of injection pressures (50–150 MPa) and ambient densities (7.6–22.8 kg/m3) relevant for diesel operating conditions. Ultra-small angle x-ray scattering (USAXS) measurements performed at the Advanced Photon Source are presented, which quantify Sauter mean diameters (SMD) within optically thick regions of the spray that are inaccessible by conventional droplet sizing measurement techniques, namely in the near-nozzle region, along the spray centerline, and within the core of the spray. To quantify droplet sizes along the periphery of the spray, a complementary technique is proposed and introduced, which leverages the ratio of path-integrated x-ray and visible laser extinction (SAMR) measurements to quantify SMD. The SAMR and USAXS measurements are then utilized to evaluate current spray models used for engine computational fluid dynamic (CFD) simulations. We explore the ability of a carefully calibrated spray model, premised on aerodynamic wave growth theory, to capture the experimentally observed trends of SMD throughout the spray. The spray structure is best predicted with an aerodynamic primary and secondary breakup process that is represented with a slower time constant and larger formed droplet size than conventionally recommended for diesel spray models. Additionally, spray model predictions suggest that droplet collisions may not influence the resultant droplet size distribution along the spray centerline in downstream regions of the spray.

  20. Prototyping of cerebral vasculature physical models.

    Science.gov (United States)

    Khan, Imad S; Kelly, Patrick D; Singer, Robert J

    2014-01-01

    Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities.

  1. Increased accuracy in mineral and hydrogeophysical modelling of HTEM data via detailed description of system transfer function and constrained inversion

    DEFF Research Database (Denmark)

    Viezzoli, Andrea; Christiansen, Anders Vest; Auken, Esben

    This paper aims at providing more insight into the parameters that need to be modelled during inversion of Helicopter TEM data for accurate modelling, both for hydrogeophysical and exploration applications. We use synthetic data to show in details the effect, both in data and in model space...

  2. Modelling of the photooxidation of toluene: conceptual ideas for validating detailed mechanisms

    Directory of Open Access Journals (Sweden)

    V. Wagner

    2003-01-01

    Full Text Available Toluene photooxidation is chosen as an example to examine how simulations of smog-chamber experiments can be used to unravel shortcomings in detailed mechanisms and to provide information on complex reaction systems that will be crucial for the design of future validation experiments. The mechanism used in this study is extracted from the Master Chemical Mechanism Version 3 (MCM v3 and has been updated with new modules for cresol and g-dicarbonyl chemistry. Model simulations are carried out for a toluene-NOx experiment undertaken at the European Photoreactor (EUPHORE. The comparison of the simulation with the experimental data reveals two fundamental shortcomings in the mechanism: OH production is too low by about 80%, and the ozone concentration at the end of the experiment is over-predicted by 55%. The radical budget was analysed to identify the key intermediates governing the radical transformation in the toluene system. Ring-opening products, particularly conjugated g-dicarbonyls, were identified as dominant radical sources in the early stages of the experiment. The analysis of the time evolution of radical production points to a missing OH source that peaks when the system reaches highest reactivity. First generation products are also of major importance for the ozone production in the system. The analysis of the radical budget suggests two options to explain the concurrent under-prediction of OH and over-prediction of ozone in the model: 1 missing oxidation processes that produce or regenerate OH without or with little NO to NO2 conversion or 2 NO3 chemistry that sequesters reactive nitrogen oxides into stable nitrogen compounds and at the same time produces peroxy radicals. Sensitivity analysis was employed to identify significant contributors to ozone production and it is shown how this technique, in combination with ozone isopleth plots, can be used for the design of validation experiments.

  3. Assessing physical models used in nuclear aerosol transport models

    International Nuclear Information System (INIS)

    McDonald, B.H.

    1987-01-01

    Computer codes used to predict the behaviour of aerosols in water-cooled reactor containment buildings after severe accidents contain a variety of physical models. Special models are in place for describing agglomeration processes where small aerosol particles combine to form larger ones. Other models are used to calculate the rates at which aerosol particles are deposited on building structures. Condensation of steam on aerosol particles is currently a very active area in aerosol modelling. In this paper, the physical models incorporated in the current available international codes for all of these processes are reviewed and documented. There is considerable variation in models used in different codes, and some uncertainties exist as to which models are superior. 28 refs

  4. Electromagnetic Physics Models for Parallel Computing Architectures

    International Nuclear Information System (INIS)

    Amadio, G; Bianchini, C; Iope, R; Ananya, A; Apostolakis, J; Aurora, A; Bandieramonte, M; Brun, R; Carminati, F; Gheata, A; Gheata, M; Goulas, I; Nikitina, T; Bhattacharyya, A; Mohanty, A; Canal, P; Elvira, D; Jun, S Y; Lima, G; Duhem, L

    2016-01-01

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part of the GeantV project. Results of preliminary performance evaluation and physics validation are presented as well. (paper)

  5. Electromagnetic Physics Models for Parallel Computing Architectures

    Science.gov (United States)

    Amadio, G.; Ananya, A.; Apostolakis, J.; Aurora, A.; Bandieramonte, M.; Bhattacharyya, A.; Bianchini, C.; Brun, R.; Canal, P.; Carminati, F.; Duhem, L.; Elvira, D.; Gheata, A.; Gheata, M.; Goulas, I.; Iope, R.; Jun, S. Y.; Lima, G.; Mohanty, A.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.; Zhang, Y.

    2016-10-01

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. GeantV, a next generation detector simulation, has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth and type of parallelization needed to achieve optimal performance. In this paper we describe implementation of electromagnetic physics models developed for parallel computing architectures as a part of the GeantV project. Results of preliminary performance evaluation and physics validation are presented as well.

  6. B physics beyond the Standard Model

    International Nuclear Information System (INIS)

    Hewett, J.A.L.

    1997-12-01

    The ability of present and future experiments to test the Standard Model in the B meson sector is described. The authors examine the loop effects of new interactions in flavor changing neutral current B decays and in Z → b anti b, concentrating on supersymmetry and the left-right symmetric model as specific examples of new physics scenarios. The procedure for performing a global fit to the Wilson coefficients which describe b → s transitions is outlined, and the results of such a fit from Monte Carlo generated data is compared to the predictions of the two sample new physics scenarios. A fit to the Zb anti b couplings from present data is also given

  7. A minimal physical model for crawling cells

    Science.gov (United States)

    Tiribocchi, Adriano; Tjhung, Elsen; Marenduzzo, Davide; Cates, Michael E.

    Cell motility in higher organisms (eukaryotes) is fundamental to biological functions such as wound healing or immune response, and is also implicated in diseases such as cancer. For cells crawling on solid surfaces, considerable insights into motility have been gained from experiments replicating such motion in vitro. Such experiments show that crawling uses a combination of actin treadmilling (polymerization), which pushes the front of a cell forward, and myosin-induced stress (contractility), which retracts the rear. We present a simplified physical model of a crawling cell, consisting of a droplet of active polar fluid with contractility throughout, but treadmilling connected to a thin layer near the supporting wall. The model shows a variety of shapes and/or motility regimes, some closely resembling cases seen experimentally. Our work supports the view that cellular motility exploits autonomous physical mechanisms whose operation does not need continuous regulatory effort.

  8. PROCESSING OF UAV BASED RANGE IMAGING DATA TO GENERATE DETAILED ELEVATION MODELS OF COMPLEX NATURAL STRUCTURES

    Directory of Open Access Journals (Sweden)

    T. K. Kohoutek

    2012-07-01

    Full Text Available Unmanned Aerial Vehicles (UAVs are more and more used in civil areas like geomatics. Autonomous navigated platforms have a great flexibility in flying and manoeuvring in complex environments to collect remote sensing data. In contrast to standard technologies such as aerial manned platforms (airplanes and helicopters UAVs are able to fly closer to the object and in small-scale areas of high-risk situations such as landslides, volcano and earthquake areas and floodplains. Thus, UAVs are sometimes the only practical alternative in areas where access is difficult and where no manned aircraft is available or even no flight permission is given. Furthermore, compared to terrestrial platforms, UAVs are not limited to specific view directions and could overcome occlusions from trees, houses and terrain structures. Equipped with image sensors and/or laser scanners they are able to provide elevation models, rectified images, textured 3D-models and maps. In this paper we will describe a UAV platform, which can carry a range imaging (RIM camera including power supply and data storage for the detailed mapping and monitoring of complex structures, such as alpine riverbed areas. The UAV platform NEO from Swiss UAV was equipped with the RIM camera CamCube 2.0 by PMD Technologies GmbH to capture the surface structures. Its navigation system includes an autopilot. To validate the UAV-trajectory a 360° prism was installed and tracked by a total station. Within the paper a workflow for the processing of UAV-RIM data is proposed, which is based on the processing of differential GNSS data in combination with the acquired range images. Subsequently, the obtained results for the trajectory are compared and verified with a track of a UAV (Falcon 8, Ascending Technologies carried out with a total station simultaneously to the GNSS data acquisition. The results showed that the UAV's position using differential GNSS could be determined in the centimetre to the decimetre

  9. Modelling soot formation from wall films in a gasoline direct injection engine using a detailed population balance model

    International Nuclear Information System (INIS)

    Wang, Buyu; Mosbach, Sebastian; Schmutzhard, Sebastian; Shuai, Shijin; Huang, Yaqing; Kraft, Markus

    2016-01-01

    Highlights: • Soot formation from a wall film in a GDI engine is simulated. • Spray impingement and wall film evaporation models are added to SRM Engine Suite. • Soot is modelled using a highly detailed population balance model. • Particle size distributions are measured experimentally. • Evolution of wall region is shown in equivalence ratio-temperature diagrams. - Abstract: In this study, soot formation in a Gasoline Direct Injection (GDI) engine is simulated using a Stochastic Reactor Model (SRM Engine Suite) which contains a detailed population balance soot model capable of describing particle morphology and chemical composition. In order to describe the soot formation originating from the wall film, the SRM Engine Suite is extended to include spray impingement and wall film evaporation models. The cylinder is divided into a wall and a bulk zone to resolve the equivalence ratio and temperature distributions of the mixture near the wall. The combustion chamber wall is assumed to exchange heat directly only with the wall zone. The turbulent mixing within each zone and between the two zones are simulated with different mixing models. The effects of key parameters on the temperature and equivalence ratio in the two zones are investigated. The mixing rate between the wall and bulk zone has a significant effect on the wall zone, whilst the mixing rate in the wall zone only has a negligible impact on the temperature and equivalence ratio below a certain threshold. Experimental data are obtained from a four-cylinder, gasoline-fuelled direct injection spark ignition engine operated stoichiometrically. An injection timing sweep, ranging from 120 CAD BTDC to 330 CAD BTDC, is conducted in order to investigate the effect of spray impingement on soot formation. The earliest injection case (330 CAD BTDC), which produces significantly higher levels of particle emissions than any other case, is simulated by the current model. It is found that the in-cylinder pressure

  10. Statistical physics of pairwise probability models

    Directory of Open Access Journals (Sweden)

    Yasser Roudi

    2009-11-01

    Full Text Available Statistical models for describing the probability distribution over the states of biological systems are commonly used for dimensional reduction. Among these models, pairwise models are very attractive in part because they can be fit using a reasonable amount of data: knowledge of the means and correlations between pairs of elements in the system is sufficient. Not surprisingly, then, using pairwise models for studying neural data has been the focus of many studies in recent years. In this paper, we describe how tools from statistical physics can be employed for studying and using pairwise models. We build on our previous work on the subject and study the relation between different methods for fitting these models and evaluating their quality. In particular, using data from simulated cortical networks we study how the quality of various approximate methods for inferring the parameters in a pairwise model depends on the time bin chosen for binning the data. We also study the effect of the size of the time bin on the model quality itself, again using simulated data. We show that using finer time bins increases the quality of the pairwise model. We offer new ways of deriving the expressions reported in our previous work for assessing the quality of pairwise models.

  11. Physical models on discrete space and time

    International Nuclear Information System (INIS)

    Lorente, M.

    1986-01-01

    The idea of space and time quantum operators with a discrete spectrum has been proposed frequently since the discovery that some physical quantities exhibit measured values that are multiples of fundamental units. This paper first reviews a number of these physical models. They are: the method of finite elements proposed by Bender et al; the quantum field theory model on discrete space-time proposed by Yamamoto; the finite dimensional quantum mechanics approach proposed by Santhanam et al; the idea of space-time as lattices of n-simplices proposed by Kaplunovsky et al; and the theory of elementary processes proposed by Weizsaecker and his colleagues. The paper then presents a model proposed by the authors and based on the (n+1)-dimensional space-time lattice where fundamental entities interact among themselves 1 to 2n in order to build up a n-dimensional cubic lattice as a ground field where the physical interactions take place. The space-time coordinates are nothing more than the labelling of the ground field and take only discrete values. 11 references

  12. CADDIS Volume 2. Sources, Stressors and Responses: Metals - Detailed Conceptual Model Diagram

    Science.gov (United States)

    Introduction to the metals module, when to list metals as a candidate cause, ways to measure metals, simple and detailed conceptual diagrams for metals, metals module references and literature reviews.

  13. Generomak: Fusion physics, engineering and costing model

    International Nuclear Information System (INIS)

    Delene, J.G.; Krakowski, R.A.; Sheffield, J.; Dory, R.A.

    1988-06-01

    A generic fusion physics, engineering and economics model (Generomak) was developed as a means of performing consistent analysis of the economic viability of alternative magnetic fusion reactors. The original Generomak model developed at Oak Ridge by Sheffield was expanded for the analyses of the Senior Committee on Environmental Safety and Economics of Magnetic Fusion Energy (ESECOM). This report describes the Generomak code as used by ESECOM. The input data used for each of the ten ESECOM fusion plants and the Generomak code output for each case is given. 14 refs., 3 figs., 17 tabs

  14. Gyrofluid Modeling of Turbulent, Kinetic Physics

    Science.gov (United States)

    Despain, Kate Marie

    2011-12-01

    Gyrofluid models to describe plasma turbulence combine the advantages of fluid models, such as lower dimensionality and well-developed intuition, with those of gyrokinetics models, such as finite Larmor radius (FLR) effects. This allows gyrofluid models to be more tractable computationally while still capturing much of the physics related to the FLR of the particles. We present a gyrofluid model derived to capture the behavior of slow solar wind turbulence and describe the computer code developed to implement the model. In addition, we describe the modifications we made to a gyrofluid model and code that simulate plasma turbulence in tokamak geometries. Specifically, we describe a nonlinear phase mixing phenomenon, part of the E x B term, that was previously missing from the model. An inherently FLR effect, it plays an important role in predicting turbulent heat flux and diffusivity levels for the plasma. We demonstrate this importance by comparing results from the updated code to studies done previously by gyrofluid and gyrokinetic codes. We further explain what would be necessary to couple the updated gyrofluid code, gryffin, to a turbulent transport code, thus allowing gryffin to play a role in predicting profiles for fusion devices such as ITER and to explore novel fusion configurations. Such a coupling would require the use of Graphical Processing Units (GPUs) to make the modeling process fast enough to be viable. Consequently, we also describe our experience with GPU computing and demonstrate that we are poised to complete a gryffin port to this innovative architecture.

  15. Agent-Based Models in Social Physics

    Science.gov (United States)

    Quang, Le Anh; Jung, Nam; Cho, Eun Sung; Choi, Jae Han; Lee, Jae Woo

    2018-06-01

    We review the agent-based models (ABM) on social physics including econophysics. The ABM consists of agent, system space, and external environment. The agent is autonomous and decides his/her behavior by interacting with the neighbors or the external environment with the rules of behavior. Agents are irrational because they have only limited information when they make decisions. They adapt using learning from past memories. Agents have various attributes and are heterogeneous. ABM is a non-equilibrium complex system that exhibits various emergence phenomena. The social complexity ABM describes human behavioral characteristics. In ABMs of econophysics, we introduce the Sugarscape model and the artificial market models. We review minority games and majority games in ABMs of game theory. Social flow ABM introduces crowding, evacuation, traffic congestion, and pedestrian dynamics. We also review ABM for opinion dynamics and voter model. We discuss features and advantages and disadvantages of Netlogo, Repast, Swarm, and Mason, which are representative platforms for implementing ABM.

  16. Process of Integrating Screening and Detailed Risk-based Modeling Analyses to Ensure Consistent and Scientifically Defensible Results

    International Nuclear Information System (INIS)

    Buck, John W.; McDonald, John P.; Taira, Randal Y.

    2002-01-01

    To support cleanup and closure of these tanks, modeling is performed to understand and predict potential impacts to human health and the environment. Pacific Northwest National Laboratory developed a screening tool for the United States Department of Energy, Office of River Protection that estimates the long-term human health risk, from a strategic planning perspective, posed by potential tank releases to the environment. This tool is being conditioned to more detailed model analyses to ensure consistency between studies and to provide scientific defensibility. Once the conditioning is complete, the system will be used to screen alternative cleanup and closure strategies. The integration of screening and detailed models provides consistent analyses, efficiencies in resources, and positive feedback between the various modeling groups. This approach of conditioning a screening methodology to more detailed analyses provides decision-makers with timely and defensible information and increases confidence in the results on the part of clients, regulators, and stakeholders

  17. Visualisation of details of a complicated inner structure of model objects by the method of diffusion optical tomography

    International Nuclear Information System (INIS)

    Tret'yakov, Evgeniy V; Shuvalov, Vladimir V; Shutov, I V

    2002-01-01

    An approximate algorithm is tested for solving the problem of diffusion optical tomography in experiments on the visualisation of details of the inner structure of strongly scattering model objects containing scattering and semitransparent inclusions, as well as absorbing inclusions located inside other optical inhomogeneities. The stability of the algorithm to errors is demonstrated, which allows its use for a rapid (2 - 3 min) image reconstruction of the details of objects with a complicated inner structure. (laser biology and medicine)

  18. Author Details

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES. Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads.

  19. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... An algorithm to retrieve Land Surface Temperature using Landsat-8 Dataset Abstract PDF. ISSN: 2225-8531.

  20. Evaluating crown fire rate of spread predictions from physics-based models

    Science.gov (United States)

    C. M. Hoffman; J. Ziegler; J. Canfield; R. R. Linn; W. Mell; C. H. Sieg; F. Pimont

    2015-01-01

    Modeling the behavior of crown fires is challenging due to the complex set of coupled processes that drive the characteristics of a spreading wildfire and the large range of spatial and temporal scales over which these processes occur. Detailed physics-based modeling approaches such as FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS) simulate...

  1. Modellus: Learning Physics with Mathematical Modelling

    Science.gov (United States)

    Teodoro, Vitor

    Computers are now a major tool in research and development in almost all scientific and technological fields. Despite recent developments, this is far from true for learning environments in schools and most undergraduate studies. This thesis proposes a framework for designing curricula where computers, and computer modelling in particular, are a major tool for learning. The framework, based on research on learning science and mathematics and on computer user interface, assumes that: 1) learning is an active process of creating meaning from representations; 2) learning takes place in a community of practice where students learn both from their own effort and from external guidance; 3) learning is a process of becoming familiar with concepts, with links between concepts, and with representations; 4) direct manipulation user interfaces allow students to explore concrete-abstract objects such as those of physics and can be used by students with minimal computer knowledge. Physics is the science of constructing models and explanations about the physical world. And mathematical models are an important type of models that are difficult for many students. These difficulties can be rooted in the fact that most students do not have an environment where they can explore functions, differential equations and iterations as primary objects that model physical phenomena--as objects-to-think-with, reifying the formal objects of physics. The framework proposes that students should be introduced to modelling in a very early stage of learning physics and mathematics, two scientific areas that must be taught in very closely related way, as they were developed since Galileo and Newton until the beginning of our century, before the rise of overspecialisation in science. At an early stage, functions are the main type of objects used to model real phenomena, such as motions. At a later stage, rates of change and equations with rates of change play an important role. This type of equations

  2. Physical-Socio-Economic Modeling of Climate Change

    Science.gov (United States)

    Chamberlain, R. G.; Vatan, F.

    2008-12-01

    /information operations model. Each of these models focuses on part of the overall picture while; each contributes information about its area of expertise to a common pool and draws from that pool and the feedbacks from the other models as needed. Existing high-quality physical models are based on analysis of the dynamic interactions of atmospheric, land, and ocean processes. The demographic model tracks the civilian demographics needed by the other models. The populations of neighborhood group age-gender cohorts are affected by births, deaths, aging, and migration. This model provides labor supply and product demand curves to the economic model. The political model focuses on political actors and describes how they use their clout to seek their goals. Clout is derived from civilian support, the formal and informal alliances that actors make with each other, military strength, wealth, and control of information. It considers how they are constrained by their cultural heritage. It deals with shifting alliances. The economic model determines local and international prices and production quantities for a small number of products, including imports and exports and black markets; wages, jobs, and unemployment for a small number of labor categories; capital, growth, and inflation; resource usage and pollution. The media/information operations model addresses the effects of the control and content of inter- group and intra-group communications-and the side effects of these on other groups. This model will consist of rules (probably a large number of them) detailing the effects of media/information operations of various kinds on civilian parameters used in the other models, such as political goals, concern saliencies, and shapes of supply and demand curves.

  3. Physics Beyond the Standard Model: Supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Nojiri, M.M.; /KEK, Tsukuba /Tsukuba, Graduate U. Adv. Studies /Tokyo U.; Plehn, T.; /Edinburgh U.; Polesello, G.; /INFN, Pavia; Alexander, John M.; /Edinburgh U.; Allanach, B.C.; /Cambridge U.; Barr, Alan J.; /Oxford U.; Benakli, K.; /Paris U., VI-VII; Boudjema, F.; /Annecy, LAPTH; Freitas, A.; /Zurich U.; Gwenlan, C.; /University Coll. London; Jager, S.; /CERN /LPSC, Grenoble

    2008-02-01

    This collection of studies on new physics at the LHC constitutes the report of the supersymmetry working group at the Workshop 'Physics at TeV Colliders', Les Houches, France, 2007. They cover the wide spectrum of phenomenology in the LHC era, from alternative models and signatures to the extraction of relevant observables, the study of the MSSM parameter space and finally to the interplay of LHC observations with additional data expected on a similar time scale. The special feature of this collection is that while not each of the studies is explicitly performed together by theoretical and experimental LHC physicists, all of them were inspired by and discussed in this particular environment.

  4. Advancing reservoir operation description in physically based hydrological models

    Science.gov (United States)

    Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir

  5. Detailed study of the cluster structure of light nuclei in a three-body model. Pt. 3

    International Nuclear Information System (INIS)

    Kukulin, V.I.; Eramzhyan, R.A.

    1990-01-01

    The multicluster dynamic model with the Pauli projection (MDMP) for treating light nuclei, developed earlier, is used to study in detail the 6 Li electromagnetic structure including all the measured elastic and inelastic, transverse and longitudinal, isoscalar and isovector electromagnetic form factors of the nucleus and to make some predictions concerning other, not yet measured, form factors. The model is also used to calculate all the measured radiation widths Γ γ0 of the excited 6 Li * states. A proper description has been obtained for most of the known electromagnetic form factors of the nucleus. The reasons for disagreement with experimental data in the case of large momentum transfers in the M1 form factors, both elastic and inelastic, are discussed. The elastic C0 form factor of 6 Li and, probably, of other light nuclei in the region of the secondary maximum is shown to be defined, to a very great extent, by the behaviour of the α-particle charge form factor in the region of its secondary maximum. The radiation widths of the 3 + 0, 2 + 0, and 1 + 0 levels have been found to be highly sensitive to minor impurities of the wavefunction components with higher orbital moments for the excited states, as well as the ground state, of 6 Li. The Siegert theorem is shown to be of great importance when studying the probabilities of transverse electromagnetic transitions. The copious results obtained by the present authors, as well as elsewhere, concerning the diverse aspects of the behaviour of six-nucleon system in the strong, weak, and electromagnetic processes are used to formulate the concept of using the given system as an extremely convenient theoretical laboratory in nuclear physics. The relevant proposals concerning future experiments are formulated. (orig.)

  6. Author Details

    African Journals Online (AJOL)

    Details PDF · Vol 22, No 2 (1999) - Articles Vegetation under different tree species in Acacia woodland in the Rift Valley of Ethiopia Details PDF · Vol 22, No 2 (1999) - Articles Preliminary evaluation of Phytomyza orobanchia (Diptera: Agromyzidae) as a controller of Orobanche spp in Ethiopia Details PDF. ISSN: 2520–7997.

  7. Author Details

    African Journals Online (AJOL)

    African Journal for Physical, Health Education, Recreation and Dance. ... time physical activity on psycho-emotional factors in Indian men and women ... time physical activity, lifestyle and healt profile of black male mid-level managers in the ...

  8. Models in Physics, Models for Physics Learning, and Why the Distinction May Matter in the Case of Electric Circuits

    Science.gov (United States)

    Hart, Christina

    2008-01-01

    Models are important both in the development of physics itself and in teaching physics. Historically, the consensus models of physics have come to embody particular ontological assumptions and epistemological commitments. Educators have generally assumed that the consensus models of physics, which have stood the test of time, will also work well…

  9. Integrating chemistry into 3D climate models: Detailed kinetics in the troposphere and stratosphere of a global climate model

    Energy Technology Data Exchange (ETDEWEB)

    Kao, C.Y.J.; Elliott, S. [Los Alamos National Lab., NM (United States). Earth and Environmental Sciences Div.; Turco, R.P.; Zhao, X. [Univ. of California, Los Angeles, CA (United States)

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The motivation for the project is to create the first complete, three-dimensional climate model that enfolds atmospheric photochemistry. The LANL chemical global climate model (GCM) not only distributes the trace greenhouse gases and modifies their concentrations within the detailed photochemical web, but also permits them to influence the radiation field and so force their own transport. Both atmospheric chemistry and fluid dynamics are nonlinear and zonally asymmetric phenomena. They can only be adequately modeled in three dimensions on the global grid. The kinetics-augmented GCM is the only program within the atmospheric community capable of investigating interaction involving chemistry and transport. The authors have conducted case studies of timely three-dimensional chemistry issues. Examples include ozone production from biomass burning plumes, kinetic feedbacks in zonally asymmetric transport phenomena with month- to year-long time scales, and volcano sulfate aerosols with respect to their potential effects on tropospheric ozone depletion.

  10. Model unspecific search for new physics in pp collisions

    International Nuclear Information System (INIS)

    Malhotra, Shivali

    2013-01-01

    The model-independent analysis systematically scans the data taken by Compact Muon Solenoid - CMS detector for deviations from the Standard Model (SM) predictions. This approach is sensitive to a variety of models for new physics due to the minimal theoretical bias i.e. without assumptions on specific models of new physics and covering a large phase space. Possible causes of the significant deviations could be insufficient understanding of the collision event generation or detector simulation, or indeed genuine new physics in the data. Thus the output of MUSiC must be seen as only the first, but important step in the potential discovery of new physics. To get the distinctive final states, events with at least one electron or muon are classified according to their content of reconstructed objects (muons, electrons, photons, jets and missing transverse energy) and sorted into event classes. A broad scan of three kinematic distributions (scalar sum of the transverse momentum, invariant mass of reconstructed objects and missing transverse energy) in those event classes is performed by identifying deviations from SM expectations, accounting for systematic uncertainties. A scanning algorithm determines the regions in the considered distributions where the measured data deviates most from the SM predictions. This search is sensitive to an excess as well as a deficit in the comparison of data and SM background. This approach has been applied to the CMS data and we have obtained the preliminary results. I will talk about the details of the analysis techniques, its implementation in analyzing CMS data, results obtained and the discussion on the discrepancy observed

  11. Concepts in particle physics a concise introduction to the standard model

    CERN Document Server

    Nair, V Parameswaran

    2018-01-01

    The 2013 discovery of the Higgs boson posed a challenge to both physics undergraduates and their instructors. Since particle physics is seldom taught at the undergraduate level, the question "what is the Higgs and why does its discovery matter?" is a common question among undergraduates. Equally, answering this question is a problem for physics instructors. This book is an attempt to put the key concepts of particle physics together in an appealing way, and yet give enough extra tidbits for students seriously considering graduate studies in particle physics. It starts with some recapitulation of relativity and quantum mechanics, and then builds on it to give both conceptual ideas regarding the Standard Model of particle physics as well as technical details. It is presented in an informal lecture style, and includes "remarks" sections where extra material, history, or technical details are presented for the interested student. The last lecture presents an assessment of the open questions, and where the future...

  12. Physical model for membrane protrusions during spreading

    International Nuclear Information System (INIS)

    Chamaraux, F; Ali, O; Fourcade, B; Keller, S; Bruckert, F

    2008-01-01

    During cell spreading onto a substrate, the kinetics of the contact area is an observable quantity. This paper is concerned with a physical approach to modeling this process in the case of ameboid motility where the membrane detaches itself from the underlying cytoskeleton at the leading edge. The physical model we propose is based on previous reports which highlight that membrane tension regulates cell spreading. Using a phenomenological feedback loop to mimic stress-dependent biochemistry, we show that the actin polymerization rate can be coupled to the stress which builds up at the margin of the contact area between the cell and the substrate. In the limit of small variation of membrane tension, we show that the actin polymerization rate can be written in a closed form. Our analysis defines characteristic lengths which depend on elastic properties of the membrane–cytoskeleton complex, such as the membrane–cytoskeleton interaction, and on molecular parameters, the rate of actin polymerization. We discuss our model in the case of axi-symmetric and non-axi-symmetric spreading and we compute the characteristic time scales as a function of fundamental elastic constants such as the strength of membrane–cytoskeleton adherence

  13. Precision Higgs Boson Physics and Implications for Beyond the Standard Model Physics Theories

    International Nuclear Information System (INIS)

    Wells, James

    2015-01-01

    The discovery of the Higgs boson is one of science's most impressive recent achievements. We have taken a leap forward in understanding what is at the heart of elementary particle mass generation. We now have a significant opportunity to develop even deeper understanding of how the fundamental laws of nature are constructed. As such, we need intense focus from the scientific community to put this discovery in its proper context, to realign and narrow our understanding of viable theory based on this positive discovery, and to detail the implications the discovery has for theories that attempt to answer questions beyond what the Standard Model can explain. This project's first main object is to develop a state-of-the-art analysis of precision Higgs boson physics. This is to be done in the tradition of the electroweak precision measurements of the LEP/SLC era. Indeed, the electroweak precision studies of the past are necessary inputs to the full precision Higgs program. Calculations will be presented to the community of Higgs boson observables that detail just how well various couplings of the Higgs boson can be measured, and more. These will be carried out using state-of-the-art theory computations coupled with the new experimental results coming in from the LHC. The project's second main objective is to utilize the results obtained from LHC Higgs boson experiments and the precision analysis, along with the direct search studies at LHC, and discern viable theories of physics beyond the Standard Model that unify physics to a deeper level. Studies will be performed on supersymmetric theories, theories of extra spatial dimensions (and related theories, such as compositeness), and theories that contain hidden sector states uniquely accessible to the Higgs boson. In addition, if data becomes incompatible with the Standard Model's low-energy effective lagrangian, new physics theories will be developed that explain the anomaly and put it into a more

  14. Detailed characterizations of a Comparative Reactivity Method (CRM) instrument: experiments vs. modelling

    Science.gov (United States)

    Michoud, V.; Hansen, R. F.; Locoge, N.; Stevens, P. S.; Dusanter, S.

    2015-04-01

    The Hydroxyl radical (OH) is an important oxidant in the daytime troposphere that controls the lifetime of most trace gases, whose oxidation leads to the formation of harmful secondary pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). In spite of the importance of OH, uncertainties remain concerning its atmospheric budget and integrated measurements of the total sink of OH can help reducing these uncertainties. In this context, several methods have been developed to measure the first-order loss rate of ambient OH, called total OH reactivity. Among these techniques, the Comparative Reactivity Method (CRM) is promising and has already been widely used in the field and in atmospheric simulation chambers. This technique relies on monitoring competitive OH reactions between a reference molecule (pyrrole) and compounds present in ambient air inside a sampling reactor. However, artefacts and interferences exist for this method and a thorough characterization of the CRM technique is needed. In this study, we present a detailed characterization of a CRM instrument, assessing the corrections that need to be applied on ambient measurements. The main corrections are, in the order of their integration in the data processing: (1) a correction for a change in relative humidity between zero air and ambient air, (2) a correction for the formation of spurious OH when artificially produced HO2 react with NO in the sampling reactor, and (3) a correction for a deviation from pseudo first-order kinetics. The dependences of these artefacts to various measurable parameters, such as the pyrrole-to-OH ratio or the bimolecular reaction rate constants of ambient trace gases with OH are also studied. From these dependences, parameterizations are proposed to correct the OH reactivity measurements from the abovementioned artefacts. A comparison of experimental and simulation results is then discussed. The simulations were performed using a 0-D box model including either (1) a

  15. A quality management model for radiation oncology physics

    International Nuclear Information System (INIS)

    Sternick, E.S.

    1991-01-01

    State-of-the-art radiation physics quality programs operate in a data rich environment. Given the abundance of recordable events, any formalism that serves to identify and monitor a set of attributes correlated with quality is to be regarded as an important management tool. The hierarchical tree structure model describes one such useful planning method. Of the several different types of tree structures, one of the most appropriate for quality management is the pyramid model. In this model, the associations between an overall program objective and the intermediate steps leading to its attainment, are indicated by both horizontal and vertical connectors. The overall objective of the system under study occupies the vertex of the pyramid, while the level immediately below contains its principal components. Further subdivisions of each component occur in successively lower levels. The tree finally terminates at a base level consisting of actions or requirements that must be fulfilled in order to satisfy the overall objective. A pyramid model for a radiation oncology physics quality program is discussed in detail. (author). 21 refs., 4 figs., 6 tabs

  16. Beyond the standard model with B and K physics

    International Nuclear Information System (INIS)

    Grossman, Y

    2003-01-01

    In the first part of the talk the flavor physics input to models beyond the standard model is described. One specific example of such new physics model is given: A model with bulk fermions in a non factorizable one extra dimension. In the second part of the talk we discuss several observables that are sensitive to new physics. We explain what type of new physics can produce deviations from the standard model predictions in each of these observables

  17. Best-estimate LOCA simulation in a PWR-W containment building with a detailed 3D GOTHIC model

    International Nuclear Information System (INIS)

    Jimenez, G.; Fernandez-Cosials, K.; Bocanegra, R.; Lopez-Alonso, E.

    2015-01-01

    The design-basis accidents in a PWR-W containment building are usually simulated with a lumped parameter model, normally used for license analysis. Nevertheless, some phenomenology is difficult to be simulated with a lumped model: the condensation rate in each structure, stagnant water areas, temperature in different compartments, sumps and recirculation pumps disabled because of lack of water, etc. Therefore, for the detailed study of the thermal-hydraulic (TH) behaviour in every room of the containment building could be more appropriate to do it with a detailed 3D representation of the containment building geometry. The main objective of this project has been to build a 3D PWR-W containment model with the GOTHIC code to analyze the detailed behavior during a design basis accident. In the process of the 3D GOTHIC model development some previous steps were necessary: a detailed CAD model of the containment, followed by a simplified model adapted to the GOTHIC geometric capabilities. Once the geometry has been adapted to the GOTHIC requirements, the 3D model is created with this information. A design-basis accident has been simulated with the 3D model (LBLOCA), and the local TH behaviour is analysed. The results show that in comparison with a lumped parameter model, high temperatures are reached locally. Nevertheless the average pressure behaviour is found to be similar to that given by a lumped parameter model. The present paper demonstrates that is possible to build a 3D PWR-W model with the GOTHIC code with enough resolution to analyse the TH behaviour in each one of the containment rooms but at the same time with reasonable computing time. Once the GOTHIC model has been created a new road is opened enabling the simulation of other accidents such as MSLB, a SBLOCA or even a long-term SBO sequence. This document is made up of an abstract and the slides of the presentation. (authors)

  18. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  19. Pre-Service Physics Teachers' Argumentation in a Model Rocketry Physics Experience

    Science.gov (United States)

    Gürel, Cem; Süzük, Erol

    2017-01-01

    This study investigates the quality of argumentation developed by a group of pre-service physics teachers' (PSPT) as an indicator of subject matter knowledge on model rocketry physics. The structure of arguments and scientific credibility model was used as a design framework in the study. The inquiry of model rocketry physics was employed in…

  20. Physical and Chemical Environmental Abstraction Model

    International Nuclear Information System (INIS)

    Nowak, E.

    2000-01-01

    As directed by a written development plan (CRWMS M and O 1999a), Task 1, an overall conceptualization of the physical and chemical environment (P/CE) in the emplacement drift is documented in this Analysis/Model Report (AMR). Included are the physical components of the engineered barrier system (EBS). The intended use of this descriptive conceptualization is to assist the Performance Assessment Department (PAD) in modeling the physical and chemical environment within a repository drift. It is also intended to assist PAD in providing a more integrated and complete in-drift geochemical model abstraction and to answer the key technical issues raised in the U.S. Nuclear Regulatory Commission (NRC) Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE) Revision 2 (NRC 1999). EBS-related features, events, and processes (FEPs) have been assembled and discussed in ''EBS FEPs/Degradation Modes Abstraction'' (CRWMS M and O 2000a). Reference AMRs listed in Section 6 address FEPs that have not been screened out. This conceptualization does not directly address those FEPs. Additional tasks described in the written development plan are recommended for future work in Section 7.3. To achieve the stated purpose, the scope of this document includes: (1) the role of in-drift physical and chemical environments in the Total System Performance Assessment (TSPA) (Section 6.1); (2) the configuration of engineered components (features) and critical locations in drifts (Sections 6.2.1 and 6.3, portions taken from EBS Radionuclide Transport Abstraction (CRWMS M and O 2000b)); (3) overview and critical locations of processes that can affect P/CE (Section 6.3); (4) couplings and relationships among features and processes in the drifts (Section 6.4); and (5) identities and uses of parameters transmitted to TSPA by some of the reference AMRs (Section 6.5). This AMR originally considered a design with backfill, and is now being updated (REV 00 ICN1) to address

  1. Relativistic nuclear physics with the spectator model

    International Nuclear Information System (INIS)

    Gross, F.

    1988-01-01

    The spectator model, a general approach to the relativistic treatment of nuclear physics problems in which spectators to nuclear interactions are put on their mass-shell, will be defined nd described. The approach grows out of the relativistic treatment of two and three body systems in which one particle is off-shell, and recent numerical results for the NN interaction will be presented. Two meson-exchange models, one with only 4 mesons (π, σ, /rho/, ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with 6 mesons (π, σ, /rho/, ω, δ, and /eta/) but a pure γ 5 γ/sup mu/ pion coupling, are shown to give very good quantitative fits to NN scattering phase shifts below 400 MeV, and also a good description of the /rho/ 40 Cα elastic scattering observables. 19 refs., 6 figs., 1 tab

  2. REPFLO model evaluation, physical and numerical consistency

    International Nuclear Information System (INIS)

    Wilson, R.N.; Holland, D.H.

    1978-11-01

    This report contains a description of some suggested changes and an evaluation of the REPFLO computer code, which models ground-water flow and nuclear-waste migration in and about a nuclear-waste repository. The discussion contained in the main body of the report is supplemented by a flow chart, presented in the Appendix of this report. The suggested changes are of four kinds: (1) technical changes to make the code compatible with a wider variety of digital computer systems; (2) changes to fill gaps in the computer code, due to missing proprietary subroutines; (3) changes to (a) correct programming errors, (b) correct logical flaws, and (c) remove unnecessary complexity; and (4) changes in the computer code logical structure to make REPFLO a more viable model from the physical point of view

  3. Physics-based models of the plasmasphere

    Energy Technology Data Exchange (ETDEWEB)

    Jordanova, Vania K [Los Alamos National Laboratory; Pierrard, Vivane [BELGIUM; Goldstein, Jerry [SWRI; Andr' e, Nicolas [ESTEC/ESA; Kotova, Galina A [SRI, RUSSIA; Lemaire, Joseph F [BELGIUM; Liemohn, Mike W [U OF MICHIGAN; Matsui, H [UNIV OF NEW HAMPSHIRE

    2008-01-01

    We describe recent progress in physics-based models of the plasmasphere using the Auid and the kinetic approaches. Global modeling of the dynamics and inAuence of the plasmasphere is presented. Results from global plasmasphere simulations are used to understand and quantify (i) the electric potential pattern and evolution during geomagnetic storms, and (ii) the inAuence of the plasmasphere on the excitation of electromagnetic ion cyclotron (ElvIIC) waves a.nd precipitation of energetic ions in the inner magnetosphere. The interactions of the plasmasphere with the ionosphere a.nd the other regions of the magnetosphere are pointed out. We show the results of simulations for the formation of the plasmapause and discuss the inAuence of plasmaspheric wind and of ultra low frequency (ULF) waves for transport of plasmaspheric material. Theoretical formulations used to model the electric field and plasma distribution in the plasmasphere are given. Model predictions are compared to recent CLUSTER and MAGE observations, but also to results of earlier models and satellite observations.

  4. Propulsion Physics Using the Chameleon Density Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will require a new theory of propulsion. Specifically one that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. The Chameleon Density Model (CDM) is one such model that could provide new paths in propulsion toward this end. The CDM is based on Chameleon Cosmology a dark matter theory; introduced by Khrouy and Weltman in 2004. Chameleon as it is hidden within known physics, where the Chameleon field represents a scalar field within and about an object; even in the vacuum. The CDM relates to density changes in the Chameleon field, where the density changes are related to matter accelerations within and about an object. These density changes in turn change how an object couples to its environment. Whereby, thrust is achieved by causing a differential in the environmental coupling about an object. As a demonstration to show that the CDM fits within known propulsion physics, this paper uses the model to estimate the thrust from a solid rocket motor. Under the CDM, a solid rocket constitutes a two body system, i.e., the changing density of the rocket and the changing density in the nozzle arising from the accelerated mass. Whereby, the interactions between these systems cause a differential coupling to the local gravity environment of the earth. It is shown that the resulting differential in coupling produces a calculated value for the thrust near equivalent to the conventional thrust model used in Sutton and Ross, Rocket Propulsion Elements. Even though imbedded in the equations are the Universe energy scale factor, the reduced Planck mass and the Planck length, which relates the large Universe scale to the subatomic scale.

  5. Working group report: Flavor physics and model building

    Indian Academy of Sciences (India)

    cO Indian Academy of Sciences. Vol. ... This is the report of flavor physics and model building working group at ... those in model building have been primarily devoted to neutrino physics. ..... [12] Andrei Gritsan, ICHEP 2004, Beijing, China.

  6. Detailed numerical modeling of a linear parallel-plate Active Magnetic Regenerator

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders

    2009-01-01

    A numerical model simulating Active Magnetic Regeneration (AMR) is presented and compared to a selection of experiments. The model is an extension and re-implementation of a previous two-dimensional model. The new model is extended to 2.5D, meaning that parasitic thermal losses are included...

  7. Adaptive Modeling of Details for Physically-Based Sound Synthesis and Propagation

    Science.gov (United States)

    2015-03-21

    CONTENTS LIST OF TABLES...Rauber, A., and Merkl, D. (2002). Content -based organization and visualization of music archives. In Proceedings of the tenth ACM international...Interactive simulation of complex audiovisual scenes. Presence: Teleoper. Virtual Environ., 13:99–111. van den Doel, K., Kry, P., and Pai, D. (2001

  8. Details of modelling HTR core physics: the use of pseudo nuclide traces

    International Nuclear Information System (INIS)

    Kuijper, J.C.; Oppe, J.; Haas, J.B.M. de; Da Cruz, D.F.

    2003-01-01

    At present most combined neutronic and thermal hydraulic analyses of reactors, and the HTR is no exception, are being performed by codes employing few-group (typically 2-group) neutronics on the basis of parametrized few-group macroscopic (and microscopic) cross sections for homogenized areas, depending on quantities like irradiation (fuel only), 135 Xe concentration, temperature, etc. The irradiation parameter (time-integrated power per unit initial heavy metal mass) is sufficient for keeping track of the evolution of areas containing fuel. However, the use of the same parameter in areas without fuel, e.g. containing burnable poison, requires some special provisions. This can be met by the introduction of pseudo nuclides, with very specific cross sections and reaction chains, in the procedure to generate the parametrized few-group cross sections. It is shown that the time-evolution of a non-fuelled burnable poison area, as calculated by the 2-group (HTR) reactor code PANTHERMIX employing pseudo nuclides, compares well to the time-evolution obtained from an explicit burnup calculation by the WIMS8A/SNAP code. Examples are also shown using the pseudo nuclide method to keep track of the fast fluence (time-integrated flux above 0.1 MeV) in a continuous reload pebble-bed HTR reactor calculation by PANTHERMIX. Although the present implementation of the pseudo nuclide method exhibits some peculiarities connected to the specific codes in use (WIMS8A and PANTHERMIX) it is considered to be sufficiently general to be applicable in other code suites, requiring only limited modifications. (authors)

  9. Details of modelling HTR core physics: the use of pseudo nuclide traces

    Energy Technology Data Exchange (ETDEWEB)

    Kuijper, J.C.; Oppe, J.; Haas, J.B.M. de; Da Cruz, D.F. [Nuclear Research and consultancy Group (NRG), Petten (Netherlands)

    2003-07-01

    At present most combined neutronic and thermal hydraulic analyses of reactors, and the HTR is no exception, are being performed by codes employing few-group (typically 2-group) neutronics on the basis of parametrized few-group macroscopic (and microscopic) cross sections for homogenized areas, depending on quantities like irradiation (fuel only), {sup 135}Xe concentration, temperature, etc. The irradiation parameter (time-integrated power per unit initial heavy metal mass) is sufficient for keeping track of the evolution of areas containing fuel. However, the use of the same parameter in areas without fuel, e.g. containing burnable poison, requires some special provisions. This can be met by the introduction of pseudo nuclides, with very specific cross sections and reaction chains, in the procedure to generate the parametrized few-group cross sections. It is shown that the time-evolution of a non-fuelled burnable poison area, as calculated by the 2-group (HTR) reactor code PANTHERMIX employing pseudo nuclides, compares well to the time-evolution obtained from an explicit burnup calculation by the WIMS8A/SNAP code. Examples are also shown using the pseudo nuclide method to keep track of the fast fluence (time-integrated flux above 0.1 MeV) in a continuous reload pebble-bed HTR reactor calculation by PANTHERMIX. Although the present implementation of the pseudo nuclide method exhibits some peculiarities connected to the specific codes in use (WIMS8A and PANTHERMIX) it is considered to be sufficiently general to be applicable in other code suites, requiring only limited modifications. (authors)

  10. A Hybrid Model for Multiscale Laser Plasma Simulations with Detailed Collisional Physics

    Science.gov (United States)

    2017-06-15

    single temperature Boltzmann grouping • Reintroduced radiation sources • Investigate grouping sensitivity • Linked with LANL database for Argon...Boltzmann grouping • Single Boltzmann grouping applies grouping to whole ionic distribution • “Worst case” scenario for accuracy • Most comparable

  11. A Hybrid Model for Multiscale Laser Plasma Simulations with Detailed Collisional Physics

    Science.gov (United States)

    2017-06-23

    or other data does not license the holder or any other person or corporation; or convey any rights or permission to manufacture, use, or sell any...Technical Advisor Rocket Propulsion Division This report is published in the interest of scientific and technical...radiative; algorithms; argon; xenon; particle in cell; Monte Carlo method ; Bhatnagar- Gross-Krook; BGK 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

  12. The 5th Generation model of Particle Physics

    Science.gov (United States)

    Lach, Theodore

    2009-05-01

    The Standard model of Particle Physics is able to account for all known HEP phenomenon, yet it is not able to predict the masses of the quarks or leptons nor can it explain why they have their respective values. The Checker Board Model (CBM) predicts that there are 5 generation of quarks and leptons and shows a pattern to those masses, namely each three quarks or leptons (within adjacent generations or within a generation) are related to each other by a geometric mean relationship. A 2D structure of the nucleus can be imaged as 2D plate spinning on its axis, it would for all practical circumstances appear to be a 3D object. The masses of the hypothesized ``up'' and ``dn'' quarks determined by the CBM are 237.31 MeV and 42.392 MeV respectively. These new quarks in addition to a lepton of 7.4 MeV make up one of the missing generations. The details of this new particle physics model can be found at the web site: checkerboard.dnsalias.net. The only areas were this theory conflicts with existing dogma is in the value of the mass of the Top quark. The particle found at Fermi Lab must be some sort of composite particle containing Top quarks.

  13. Computational Methods for Physical Model Information Management: Opening the Aperture

    International Nuclear Information System (INIS)

    Moser, F.; Kirgoeze, R.; Gagne, D.; Calle, D.; Murray, J.; Crowley, J.

    2015-01-01

    The volume, velocity and diversity of data available to analysts are growing exponentially, increasing the demands on analysts to stay abreast of developments in their areas of investigation. In parallel to the growth in data, technologies have been developed to efficiently process, store, and effectively extract information suitable for the development of a knowledge base capable of supporting inferential (decision logic) reasoning over semantic spaces. These technologies and methodologies, in effect, allow for automated discovery and mapping of information to specific steps in the Physical Model (Safeguard's standard reference of the Nuclear Fuel Cycle). This paper will describe and demonstrate an integrated service under development at the IAEA that utilizes machine learning techniques, computational natural language models, Bayesian methods and semantic/ontological reasoning capabilities to process large volumes of (streaming) information and associate relevant, discovered information to the appropriate process step in the Physical Model. The paper will detail how this capability will consume open source and controlled information sources and be integrated with other capabilities within the analysis environment, and provide the basis for a semantic knowledge base suitable for hosting future mission focused applications. (author)

  14. Fuzzy modelling of Atlantic salmon physical habitat

    Science.gov (United States)

    St-Hilaire, André; Mocq, Julien; Cunjak, Richard

    2015-04-01

    Fish habitat models typically attempt to quantify the amount of available river habitat for a given fish species for various flow and hydraulic conditions. To achieve this, information on the preferred range of values of key physical habitat variables (e.g. water level, velocity, substrate diameter) for the targeted fishs pecies need to be modelled. In this context, we developed several habitat suitability indices sets for three Atlantic salmon life stages (young-of-the-year (YOY), parr, spawning adults) with the help of fuzzy logic modeling. Using the knowledge of twenty-seven experts, from both sides of the Atlantic Ocean, we defined fuzzy sets of four variables (depth, substrate size, velocity and Habitat Suitability Index, or HSI) and associated fuzzy rules. When applied to the Romaine River (Canada), median curves of standardized Weighted Usable Area (WUA) were calculated and a confidence interval was obtained by bootstrap resampling. Despite the large range of WUA covered by the expert WUA curves, confidence intervals were relatively narrow: an average width of 0.095 (on a scale of 0 to 1) for spawning habitat, 0.155 for parr rearing habitat and 0.160 for YOY rearing habitat. When considering an environmental flow value corresponding to 90% of the maximum reached by WUA curve, results seem acceptable for the Romaine River. Generally, this proposed fuzzy logic method seems suitable to model habitat availability for the three life stages, while also providing an estimate of uncertainty in salmon preferences.

  15. Author Details

    African Journals Online (AJOL)

    Petrology of the Cenomanian Upper Member of the Mamfe Embayment, southwestern Cameroon Details · Vol 38, No 1 (2002) - Articles Sequence stratigraphy of Iso field, western onshore Niger Delta, Nigeria Details · Vol 39, No 2 (2003) - Articles Preliminary studies on the lithostratigraphy and depositional environment of ...

  16. Author Details

    African Journals Online (AJOL)

    An Overview of Africa's Marine Resources: Their Utilization and Sustainable Management Details · Vol 12, No 3 (2000) - Articles EDITORIAL Ganoderma Lucidum - Paramount among Medicinal Mushrooms. Details · Vol 15, No 3 (2003) - Articles Editorial: Africa's Mushrooms: A neglected bioresource whose time has come

  17. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Abstract PDF · Vol 3, No 6 (2011) - Articles Mixed convection flow and heat transfer in a vertical wavy channel containing porous and fluid layer with traveling thermal waves. Abstract PDF · Vol 3, No 8 ...

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    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Singh, J. Vol 3, No 2 (2011) - Articles Plane waves in a rotating generalized thermo-elastic solid with voids. Abstract PDF. ISSN: 2141-2839. AJOL African Journals Online. HOW TO USE AJOL.

  19. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Vol 12 (2008) - Articles On the wave equations of shallow water with rough bottom topography. Abstract · Vol 14 (2009) - Articles Energy generation in a plant due to variable sunlight intensity

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    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Iliopsoas haematoma in a rugby player. Abstract PDF · Vol 29, No 1 (2017) - Articles The use of negative pressure wave treatment in athlete recovery. Abstract PDF. ISSN: 2078-516X. AJOL African ...

  1. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Ismail, A. Vol 9, No 3S (2017): Special Issue - Articles Investigate of wave absorption performance for oil palm frond and empty fruit bunch at 5.8 GHz. Abstract PDF · Vol 9, No 3S (2017): Special Issue ...

  2. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Isa, M.F.M.. Vol 9, No 3S (2017): Special Issue - Articles Experimental and numerical investigation on blast wave propagation in soil structure. Abstract PDF · Vol 9, No 3S (2017): Special Issue - ...

  3. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... No 3S (2017): Special Issue - Articles Experimental and numerical investigation on blast wave propagation in soil structure. Abstract PDF · Vol 9, No 3S (2017): Special Issue - Articles Simulation on ...

  4. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Duwa, S S. Vol 8 (2004) - Articles Lower hybrid waves instability in a velocity–sheared inhomogenous charged dust beam. Abstract · Vol 9 (2005) - Articles The slide away theory of lower hybrid bursts

  5. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Vol 45 (2016) - Articles From vectors to waves and streams: An alternative approach to semantic maps1. Abstract PDF · Vol 48 (2017) - Articles Introduction: 'n Klein ietsie for Johan Oosthuizen

  6. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... to blast loadings. Abstract PDF · Vol 9, No 3S (2017): Special Issue - Articles Experimental and numerical investigation on blast wave propagation in soil structure. Abstract PDF. ISSN: 1112-9867.

  7. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... The use of negative pressure wave treatment in athlete recovery. Abstract PDF · Vol 29, No 1 (2017) - Articles The prevalence, risk factors predicting injury and the severity of injuries sustained during ...

  8. Author Details

    African Journals Online (AJOL)

    Author Details. Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Vol 29, No 1 (2017) - Articles The use of negative pressure wave treatment in athlete recovery. Abstract PDF · Vol 29, No 1 (2017) - Articles The prevalence, risk factors predicting injury and the ...

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    African Journals Online (AJOL)

    Relationship between physique, under nutrition, physical fitness and bloody ... Body composition in urban black South African school children aged 6-13 years ... Physical growth and academic intelligence of rural South African children: ...

  10. An Outcrop-based Detailed Geological Model to Test Automated Interpretation of Seismic Inversion Results

    NARCIS (Netherlands)

    Feng, R.; Sharma, S.; Luthi, S.M.; Gisolf, A.

    2015-01-01

    Previously, Tetyukhina et al. (2014) developed a geological and petrophysical model based on the Book Cliffs outcrops that contained eight lithotypes. For reservoir modelling purposes, this model is judged to be too coarse because in the same lithotype it contains reservoir and non-reservoir

  11. Author Details

    African Journals Online (AJOL)

    Stephen, U. Vol 1, No 1 (2012) - Articles Integrative Strategy for Effective Teaching of Alternating Circuits in Secondary School Physics: A Guide to Physics Teachers Abstract PDF · Vol 1, No 3 (2012) - Articles Integrative Strategy for Effective Teaching of Density and Pressure in Senior Secondary Schools: A Guide to Physics ...

  12. Statistical Analysis of Detailed 3-D CFD LES Simulations with Regard to CCV Modeling

    Directory of Open Access Journals (Sweden)

    Vítek Oldřich

    2016-06-01

    Full Text Available The paper deals with statistical analysis of large amount of detailed 3-D CFD data in terms of cycle-to-cycle variations (CCVs. These data were obtained by means of LES calculations of many consecutive cycles. Due to non-linear nature of Navier-Stokes equation set, there is a relatively significant CCV. Hence, every cycle is slightly different – this leads to requirement to perform statistical analysis based on ensemble averaging procedure which enables better understanding of CCV in ICE including its quantification. The data obtained from the averaging procedure provides results on different space resolution levels. The procedure is applied locally, i.e., in every cell of the mesh. Hence there is detailed CCV information on local level – such information can be compared with RANS simulations. Next, volume/mass averaging provides information at specific locations – e.g., gap between electrodes of a spark plug. Finally, volume/mass averaging of the whole combustion chamber leads to global information which can be compared with experimental data or results of system simulation tools (which are based on 0-D/1-D approach.

  13. Establishment of detailed eye model of adult chinese male and dose conversion coefficients calculation under neutron exposure

    International Nuclear Information System (INIS)

    Zhu, Hongyu; Qiu, Rui; Ren, Li; Zhang, Hui; Li, Junli; Wu, Zhen; Li, Chunyan

    2017-01-01

    The human eye lens is sensitive to radiation. ICRP-118 publication recommended a reduction of the occupational annual equivalent dose limit from 150 to 20 mSv, averaged over defined periods of 5 y. Therefore, it is very important to build a detailed eye model for the accurate dose assessment and radiation risk evaluation of eye lens. In this work, a detailed eye model was build based on the characteristic anatomic parameters of the Chinese adult male. This eye model includes seven main structures, which are scleral, choroid, lens, iris, cornea, vitreous body and aqueous humor. The lens was divided into sensitive volume and insensitive volume based on different cell populations. The detailed eye model was incorporated into the converted polygon-mesh version of the Chinese reference adult male whole-body surface model. After the incorporation, dose conversion coefficients for the eye lens were calculated for neutron exposure at AP, PA and LAT geometries with Geant4, the neutron energies were from 0.001 eV to 10 MeV. The calculated lens dose coefficients were compared with those of ICRP-116 publication. Significant differences up to 97.47% were found at PA geometry. This could mainly be attributed to the different geometry characteristic of eye model and parameters of head in different phantom between the present work and ICRP-116 publication. (authors)

  14. ESTABLISHMENT OF DETAILED EYE MODEL OF ADULT CHINESE MALE AND DOSE CONVERSION COEFFICIENTS CALCULATION UNDER NEUTRON EXPOSURE.

    Science.gov (United States)

    Zhu, Hongyu; Qiu, Rui; Wu, Zhen; Ren, Li; Li, Chunyan; Zhang, Hui; Li, Junli

    2017-12-01

    The human eye lens is sensitive to radiation. ICRP-118 publication recommended a reduction of the occupational annual equivalent dose limit from 150 to 20 mSv, averaged over defined periods of 5 y. Therefore, it is very important to build a detailed eye model for the accurate dose assessment and radiation risk evaluation of eye lens. In this work, a detailed eye model was build based on the characteristic anatomic parameters of the Chinese adult male. This eye model includes seven main structures, which are scleral, choroid, lens, iris, cornea, vitreous body and aqueous humor. The lens was divided into sensitive volume and insensitive volume based on different cell populations. The detailed eye model was incorporated into the converted polygon-mesh version of the Chinese reference adult male whole-body surface model. After the incorporation, dose conversion coefficients for the eye lens were calculated for neutron exposure at AP, PA and LAT geometries with Geant4, the neutron energies were from 0.001 eV to 10 MeV. The calculated lens dose coefficients were compared with those of ICRP-116 publication. Significant differences up to 97.47% were found at PA geometry. This could mainly be attributed to the different geometry characteristic of eye model and parameters of head in different phantom between the present work and ICRP-116 publication. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. SNAP: a tool for nuclear physical protection system modeling

    International Nuclear Information System (INIS)

    Engi, D.; Grant, F.H. III.

    1979-10-01

    Nuclear safeguards systems are concerned, in part, with the physical protection of nuclear materials. The function of a physical protection system is to define the facility against adversary activities which could lead to theft of nuclear material or sabotage resulting in a radiological release. The Safeguards Network Analysis Procedure (SNAP) provides a convenient and standard analysis methodology for the evaluation of physical protection system analysis. This paper describes a detailed application of SNAP to a hypothetical nuclear facility

  16. A Holoinformational Model of the Physical Observer

    Science.gov (United States)

    di Biase, Francisco

    2013-09-01

    The author proposes a holoinformational view of the observer based, on the holonomic theory of brain/mind function and quantum brain dynamics developed by Karl Pribram, Sir John Eccles, R.L. Amoroso, Hameroff, Jibu and Yasue, and in the quantumholographic and holomovement theory of David Bohm. This conceptual framework is integrated with nonlocal information properties of the Quantum Field Theory of Umesawa, with the concept of negentropy, order, and organization developed by Shannon, Wiener, Szilard and Brillouin, and to the theories of self-organization and complexity of Prigogine, Atlan, Jantsch and Kauffman. Wheeler's "it from bit" concept of a participatory universe, and the developments of the physics of information made by Zureck and others with the concepts of statistical entropy and algorithmic entropy, related to the number of bits being processed in the mind of the observer are also considered. This new synthesis gives a self-organizing quantum nonlocal informational basis for a new model of awareness in a participatory universe. In this synthesis, awareness is conceived as meaningful quantum nonlocal information interconnecting the brain and the cosmos, by a holoinformational unified field (integrating nonlocal holistic (quantum) and local (Newtonian). We propose that the cosmology of the physical observer is this unified nonlocal quantum-holographic cosmos manifesting itself through awareness, interconnected in a participatory holistic and indivisible way the human mind-brain to all levels of the self-organizing holographic anthropic multiverse.

  17. Surface physics theoretical models and experimental methods

    CERN Document Server

    Mamonova, Marina V; Prudnikova, I A

    2016-01-01

    The demands of production, such as thin films in microelectronics, rely on consideration of factors influencing the interaction of dissimilar materials that make contact with their surfaces. Bond formation between surface layers of dissimilar condensed solids-termed adhesion-depends on the nature of the contacting bodies. Thus, it is necessary to determine the characteristics of adhesion interaction of different materials from both applied and fundamental perspectives of surface phenomena. Given the difficulty in obtaining reliable experimental values of the adhesion strength of coatings, the theoretical approach to determining adhesion characteristics becomes more important. Surface Physics: Theoretical Models and Experimental Methods presents straightforward and efficient approaches and methods developed by the authors that enable the calculation of surface and adhesion characteristics for a wide range of materials: metals, alloys, semiconductors, and complex compounds. The authors compare results from the ...

  18. Mathematical models of physics problems (physics research and technology)

    CERN Document Server

    Anchordoqui, Luis Alfredo

    2013-01-01

    This textbook is intended to provide a foundation for a one-semester introductory course on the advanced mathematical methods that form the cornerstones of the hard sciences and engineering. The work is suitable for first year graduate or advanced undergraduate students in the fields of Physics, Astronomy and Engineering. This text therefore employs a condensed narrative sufficient to prepare graduate and advanced undergraduate students for the level of mathematics expected in more advanced graduate physics courses, without too much exposition on related but non-essential material. In contrast to the two semesters traditionally devoted to mathematical methods for physicists, the material in this book has been quite distilled, making it a suitable guide for a one-semester course. The assumption is that the student, once versed in the fundamentals, can master more esoteric aspects of these topics on his or her own if and when the need arises during the course of conducting research. The book focuses on two cor...

  19. Differences in spatial understanding between physical and virtual models

    Directory of Open Access Journals (Sweden)

    Lei Sun

    2014-03-01

    Full Text Available In the digital age, physical models are still used as major tools in architectural and urban design processes. The reason why designers still use physical models remains unclear. In addition, physical and 3D virtual models have yet to be differentiated. The answers to these questions are too complex to account for in all aspects. Thus, this study only focuses on the differences in spatial understanding between physical and virtual models. In particular, it emphasizes on the perception of scale. For our experiment, respondents were shown a physical model and a virtual model consecutively. A questionnaire was then used to ask the respondents to evaluate these models objectively and to establish which model was more accurate in conveying object size. Compared with the virtual model, the physical model tended to enable quicker and more accurate comparisons of building heights.

  20. A Detailed Analytical Study of Non-Linear Semiconductor Device Modelling

    Directory of Open Access Journals (Sweden)

    Umesh Kumar

    1995-01-01

    junction diode have been developed. The results of computer simulated examples have been presented in each case. The non-linear lumped model for Gunn is a unified model as it describes the diffusion effects as the-domain traves from cathode to anode. An additional feature of this model is that it describes the domain extinction and nucleation phenomena in Gunn dioder with the help of a simple timing circuit. The non-linear lumped model for SCR is general and is valid under any mode of operation in any circuit environment. The memristive circuit model for p-n junction diodes is capable of simulating realistically the diode’s dynamic behavior under reverse, forward and sinusiodal operating modes. The model uses memristor, the charge-controlled resistor to mimic various second-order effects due to conductivity modulation. It is found that both storage time and fall time of the diode can be accurately predicted.

  1. Development of a Detailed Volumetric Finite Element Model of the Spine to Simulate Surgical Correction of Spinal Deformities

    Directory of Open Access Journals (Sweden)

    Mark Driscoll

    2013-01-01

    Full Text Available A large spectrum of medical devices exists; it aims to correct deformities associated with spinal disorders. The development of a detailed volumetric finite element model of the osteoligamentous spine would serve as a valuable tool to assess, compare, and optimize spinal devices. Thus the purpose of the study was to develop and initiate validation of a detailed osteoligamentous finite element model of the spine with simulated correction from spinal instrumentation. A finite element of the spine from T1 to L5 was developed using properties and geometry from the published literature and patient data. Spinal instrumentation, consisting of segmental translation of a scoliotic spine, was emulated. Postoperative patient and relevant published data of intervertebral disc stress, screw/vertebra pullout forces, and spinal profiles was used to evaluate the models validity. Intervertebral disc and vertebral reaction stresses respected published in vivo, ex vivo, and in silico values. Screw/vertebra reaction forces agreed with accepted pullout threshold values. Cobb angle measurements of spinal deformity following simulated surgical instrumentation corroborated with patient data. This computational biomechanical analysis validated a detailed volumetric spine model. Future studies seek to exploit the model to explore the performance of corrective spinal devices.

  2. Author Details

    African Journals Online (AJOL)

    Journal Home > Advanced Search > Author Details. Log in or Register ... (2013) - Articles Technical Note: Development of a Photobioreactor for Microalgae Culture ... Design, Construction and Evaluation of Motorized Okra Slicer Abstract PDF ...

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    African Journals Online (AJOL)

    Journal Home > Advanced Search > Author Details. Log in or Register to ... No 1 (2014) - Articles Knowledge and Attitudes towards Basic Cardiopulmonary Resuscitation (CPR) among Community Nurses in Remo Area of Ogun State, Nigeria

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    African Journals Online (AJOL)

    Journal Home > Advanced Search > Author Details. Log in or Register to get ... Optical bus of centralized relay protection and automation system of medium voltage switchgear for data collection and transmission. Abstract PDF. ISSN: 1112- ...

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    Journal Home > Advanced Search > Author Details. Log in or ... The prevention of mother-to-child HIV transmission programme and infant feeding practices ... Evaluation of a diagnostic algorithm for smear-negative pulmonary tuberculosis in ...

  6. Detailed analysis of the continuum limit of a supersymmetric lattice model in 1D

    International Nuclear Information System (INIS)

    Huijse, L

    2011-01-01

    We present a full identification of lattice model properties with their field theoretical counterparts in the continuum limit for a supersymmetric model for itinerant spinless fermions on a one-dimensional chain. The continuum limit of this model is described by an N=(2,2) superconformal field theory (SCFT) with central charge c = 1. We identify states and operators in the lattice model with fields in the SCFT and we relate boundary conditions on the lattice to sectors in the field theory. We use the dictionary we develop in this paper to give a pedagogical explanation of a powerful tool to study supersymmetric models based on spectral flow (Huijse 2008 Phys. Rev. Lett. 101 146406). Finally, we employ the developed machinery to explain numerically observed properties of the particle density on the open chain presented in Beccaria and De Angelis (2005 Phys. Rev. Lett. 94 100401)

  7. Physical Model Method for Seismic Study of Concrete Dams

    Directory of Open Access Journals (Sweden)

    Bogdan Roşca

    2008-01-01

    Full Text Available The study of the dynamic behaviour of concrete dams by means of the physical model method is very useful to understand the failure mechanism of these structures to action of the strong earthquakes. Physical model method consists in two main processes. Firstly, a study model must be designed by a physical modeling process using the dynamic modeling theory. The result is a equations system of dimensioning the physical model. After the construction and instrumentation of the scale physical model a structural analysis based on experimental means is performed. The experimental results are gathered and are available to be analysed. Depending on the aim of the research may be designed an elastic or a failure physical model. The requirements for the elastic model construction are easier to accomplish in contrast with those required for a failure model, but the obtained results provide narrow information. In order to study the behaviour of concrete dams to strong seismic action is required the employment of failure physical models able to simulate accurately the possible opening of joint, sliding between concrete blocks and the cracking of concrete. The design relations for both elastic and failure physical models are based on dimensional analysis and consist of similitude relations among the physical quantities involved in the phenomenon. The using of physical models of great or medium dimensions as well as its instrumentation creates great advantages, but this operation involves a large amount of financial, logistic and time resources.

  8. Soil physical properties influencing the fitting parameters in Philip and Kostiakov infiltration models

    International Nuclear Information System (INIS)

    Mbagwu, J.S.C.

    1994-05-01

    Among the many models developed for monitoring the infiltration process those of Philip and Kostiakov have been studied in detail because of their simplicity and the ease of estimating their fitting parameters. The important soil physical factors influencing the fitting parameters in these infiltration models are reported in this study. The results of the study show that the single most important soil property affecting the fitting parameters in these models is the effective porosity. 36 refs, 2 figs, 5 tabs

  9. Building a semantic web-based metadata repository for facilitating detailed clinical modeling in cancer genome studies.

    Science.gov (United States)

    Sharma, Deepak K; Solbrig, Harold R; Tao, Cui; Weng, Chunhua; Chute, Christopher G; Jiang, Guoqian

    2017-06-05

    Detailed Clinical Models (DCMs) have been regarded as the basis for retaining computable meaning when data are exchanged between heterogeneous computer systems. To better support clinical cancer data capturing and reporting, there is an emerging need to develop informatics solutions for standards-based clinical models in cancer study domains. The objective of the study is to develop and evaluate a cancer genome study metadata management system that serves as a key infrastructure in supporting clinical information modeling in cancer genome study domains. We leveraged a Semantic Web-based metadata repository enhanced with both ISO11179 metadata standard and Clinical Information Modeling Initiative (CIMI) Reference Model. We used the common data elements (CDEs) defined in The Cancer Genome Atlas (TCGA) data dictionary, and extracted the metadata of the CDEs using the NCI Cancer Data Standards Repository (caDSR) CDE dataset rendered in the Resource Description Framework (RDF). The ITEM/ITEM_GROUP pattern defined in the latest CIMI Reference Model is used to represent reusable model elements (mini-Archetypes). We produced a metadata repository with 38 clinical cancer genome study domains, comprising a rich collection of mini-Archetype pattern instances. We performed a case study of the domain "clinical pharmaceutical" in the TCGA data dictionary and demonstrated enriched data elements in the metadata repository are very useful in support of building detailed clinical models. Our informatics approach leveraging Semantic Web technologies provides an effective way to build a CIMI-compliant metadata repository that would facilitate the detailed clinical modeling to support use cases beyond TCGA in clinical cancer study domains.

  10. Bounds on quantum collapse models from matter-wave interferometry: calculational details

    Science.gov (United States)

    Toroš, Marko; Bassi, Angelo

    2018-03-01

    We present a simple derivation of the interference pattern in matter-wave interferometry predicted by a class of quantum master equations. We apply the obtained formulae to the following collapse models: the Ghirardi-Rimini-Weber (GRW) model, the continuous spontaneous localization (CSL) model together with its dissipative (dCSL) and non-Markovian generalizations (cCSL), the quantum mechanics with universal position localization (QMUPL), and the Diósi-Penrose (DP) model. We discuss the separability of the dynamics of the collapse models along the three spatial directions, the validity of the paraxial approximation, and the amplification mechanism. We obtain analytical expressions both in the far field and near field limits. These results agree with those already derived in the Wigner function formalism. We compare the theoretical predictions with the experimental data from two recent matter-wave experiments: the 2012 far-field experiment of Juffmann T et al (2012 Nat. Nanotechnol. 7 297-300) and the 2013 Kapitza-Dirac-Talbot-Lau (KDTL) near-field experiment of Eibenberger et al (2013 Phys. Chem. Chem. Phys. 15 14696-700). We show the region of the parameter space for each collapse model that is excluded by these experiments. We show that matter-wave experiments provide model-insensitive bounds that are valid for a wide family of dissipative and non-Markovian generalizations.

  11. Detailed measurements and modelling of thermo active components using a room size test facility

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    measurements in an office sized test facility with thermo active ceiling and floor as well as modelling of similar conditions in a computer program designed for analysis of building integrated heating and cooling systems. A method for characterizing the cooling capacity of thermo active components is described...... typically within 1-2K of the measured results. The simulation model, whose room model splits up the radiative and convective heat transfer between room and surfaces, can also be used to predict the dynamical conditions, where especially the temperature rise during the day is important for designing...

  12. Network-constrained Cournot models of liberalized electricity markets: the devil is in the details

    International Nuclear Information System (INIS)

    Neuhoff, Karsten; Barquin, Julian; Vazquez, Miguel; Boots, Maroeska; Rijkers, Fieke A.M.; Ehrenmann, Andreas; Hobbs, Benjamin F.

    2005-01-01

    Numerical models of transmission-constrained electricity markets are used to inform regulatory decisions. How robust are their results? Three research groups used the same data set for the northwest Europe power market as input for their models. Under competitive conditions, the results coincide, but in the Cournot case, the predicted prices differed significantly. The Cournot equilibria are highly sensitive to assumptions about market design (whether timing of generation and transmission decisions is sequential or integrated) and expectations of generators regarding how their decisions affect transmission prices and fringe generation. These sensitivities are qualitatively similar to those predicted by a simple two-node model. (Author)

  13. Network-constrained Cournot models of liberalized electricity markets. The devil is in the details

    Energy Technology Data Exchange (ETDEWEB)

    Neuhoff, Karsten [Department of Applied Economics, Sidgwick Ave., University of Cambridge, CB3 9DE (United Kingdom); Barquin, Julian; Vazquez, Miguel [Instituto de Investigacion Tecnologica, Universidad Pontificia Comillas, c/Santa Cruz de Marcenado 26-28015 Madrid (Spain); Boots, Maroeska G. [Energy Research Centre of the Netherlands ECN, Badhuisweg 3, 1031 CM Amsterdam (Netherlands); Ehrenmann, Andreas [Judge Institute of Management, University of Cambridge, Trumpington Street, CB2 1AG (United Kingdom); Hobbs, Benjamin F. [Department of Geography and Environmental Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Rijkers, Fieke A.M. [Contributed while at ECN, now at Nederlandse Mededingingsautoriteit (NMa), Dte, Postbus 16326, 2500 BH Den Haag (Netherlands)

    2005-05-15

    Numerical models of transmission-constrained electricity markets are used to inform regulatory decisions. How robust are their results? Three research groups used the same data set for the northwest Europe power market as input for their models. Under competitive conditions, the results coincide, but in the Cournot case, the predicted prices differed significantly. The Cournot equilibria are highly sensitive to assumptions about market design (whether timing of generation and transmission decisions is sequential or integrated) and expectations of generators regarding how their decisions affect transmission prices and fringe generation. These sensitivities are qualitatively similar to those predicted by a simple two-node model.

  14. Network-constrained Cournot models of liberalized electricity markets: the devil is in the details

    Energy Technology Data Exchange (ETDEWEB)

    Neuhoff, Karsten [Cambridge Univ., Dept. of Applied Economics, Cambridge (United Kingdom); Barquin, Julian; Vazquez, Miguel [Universidad Pontificia Comillas, Inst. de Investigacion Tecnologica, Madrid (Spain); Boots, Maroeska; Rijkers, Fieke A.M. [Energy Research Centre of the Netherlands ECN, Amsterdam (Netherlands); Ehrenmann, Andreas [Cambridge Univ., Judge Inst. of Management, Cambridge (United Kingdom); Hobbs, Benjamin F. [Johns Hopkins Univ., Dept. of Geography and Environmental Engineering, Baltimore, MD (United States)

    2005-05-01

    Numerical models of transmission-constrained electricity markets are used to inform regulatory decisions. How robust are their results? Three research groups used the same data set for the northwest Europe power market as input for their models. Under competitive conditions, the results coincide, but in the Cournot case, the predicted prices differed significantly. The Cournot equilibria are highly sensitive to assumptions about market design (whether timing of generation and transmission decisions is sequential or integrated) and expectations of generators regarding how their decisions affect transmission prices and fringe generation. These sensitivities are qualitatively similar to those predicted by a simple two-node model. (Author)

  15. Chemico-physical models of cometary atmospheres

    International Nuclear Information System (INIS)

    Huebner, W.F.; Keady, J.J.; Boice, D.C.; Schmidt, H.U.; Wegmann, R.

    1985-01-01

    Sublimation (vaporization) of the icy component of a cometary nucleus determines the initial composition of the coma gas as it streams outward and escapes. Photolytic reactions in the inner coma, escape of fast, light species such as atomic and molecular hydrogen, and solar wind interaction in the outer coma alter the chemical composition and the physical nature of the coma gas. Models that describe these interactions must include (1) chemical kinetics, (2) coma energy balance, (3) multifluid flow for the rapidly escaping light components, the heavier bulk fluid, and the plasma with separate temperatures for electrons and the remainder of the gas, (4) transition from a collision dominated inner region to free molecular flow of neutrals in the outer region, (5) pickup of cometary ions by the solar wind, (6) counter and cross streaming of neutrals with respect to the plasma which outside of the contact surface also contains solar wind ions, and (7) magnetic fields carried by the solar wind. Progress on such models is described and results including velocity, temperature, and number density profiles for important chemical species are presented and compared with observations

  16. Physical model of optical inhomogeneities of water

    Science.gov (United States)

    Shybanov, E. B.

    2017-11-01

    The paper is devoted to theoretical aspects of the light scattering of water that does not contain suspended particles. To be consistent with current physical point of view the water as far as any liquid is regarded as a complex unstable nonergodic media. It was proposed that at fixed time the water as a condensed medium had global inhomogeneities similar to linear and planar defects in a solid. Anticipated own global inhomogeneities of water have been approximated by the system randomly distributed spherical clusters filling the entire water bulk. An analytical expression for the single scattered light has been derived. The formula simultaneously describes both the high anisotropy of light scattering and the high degree of polarization which one close to those for molecular scattering. It is shown that at general angles there is a qualitative coincidence with the two-component Kopelevich's model for the light scattering by marine particles. On the contrary towards to forwards angles the spectral law becomes much more prominent i.e. it corresponds to results for model of optically soft particles.

  17. A model for determining the scope and level of detail that is appropriate for a programmatic EIS

    International Nuclear Information System (INIS)

    Eccleston, C.H.

    1995-03-01

    Since the inception of the National Environmental Policy Act (NEPA), no definitive guidance has been established for determining the scope of topics and issues, or the level of detail suitable for presentation within a Programmatic Environmental Impact Statement (P-EIS). Lacking such guidance, an inordinate amount of time and resources can be expended in determining the scope that is most appropriately addressed within a P-EIS versus the more detailed scope that is best reserved for lower-tier documents. Faced with this predicament, agencies often err on the side of including too much detail, resulting in P-EISs that are over bloated and unnecessarily complex. Moreover, lack of definitive guidance leads to a great deal of inconsistency in the preparation of P-EISs among federal agency programs. A paradigm for assisting decisionmakers in making such determinations is presented below. This model expedites the preparation of P-EISs by providing a consistent and systematic approach for determining the scope and level of detail that is most appropriately addressed at the programmatic level. In many cases, the model provides agencies with an effective tool for managing and streamlining the NEPA process by de-scoping needless and unnecessary issues from the scope of a P-EIS

  18. Detailed H2 and CO Electrochemistry for a MEA Model Fueled by Syngas

    KAUST Repository

    Lee, W. Y.; Ong, K. M.; Ghoniem, A. F.

    2015-01-01

    © The Electrochemical Society. SOFCs can directly oxidize CO in addition to H2, which allows them to be coupled to a gasifier. Many membrane-electrode-assembly (MEA) models neglect CO electrochemistry due to sluggish kinetics and the water

  19. Detailed finite element method modeling of evaporating multi-component droplets

    Energy Technology Data Exchange (ETDEWEB)

    Diddens, Christian, E-mail: C.Diddens@tue.nl

    2017-07-01

    The evaporation of sessile multi-component droplets is modeled with an axisymmetic finite element method. The model comprises the coupled processes of mixture evaporation, multi-component flow with composition-dependent fluid properties and thermal effects. Based on representative examples of water–glycerol and water–ethanol droplets, regular and chaotic examples of solutal Marangoni flows are discussed. Furthermore, the relevance of the substrate thickness for the evaporative cooling of volatile binary mixture droplets is pointed out. It is shown how the evaporation of the more volatile component can drastically decrease the interface temperature, so that ambient vapor of the less volatile component condenses on the droplet. Finally, results of this model are compared with corresponding results of a lubrication theory model, showing that the application of lubrication theory can cause considerable errors even for moderate contact angles of 40°. - Graphical abstract:.

  20. Towards a detailed on-road vehicle emissions inventory: The use of a travel demand model

    CSIR Research Space (South Africa)

    Naidoo, Mogesh

    2016-10-01

    Full Text Available of Vehicle Kilometres Travelled (VKT) for every model grid cell. This has proven difficult in South Africa as well as internationally with methodologies ranging from generalized spatial surrogate application (leading to many assumptions being incorporated...

  1. Surface detail reproduction and dimensional accuracy of stone models: influence of disinfectant solutions and alginate impression materials.

    Science.gov (United States)

    Guiraldo, Ricardo Danil; Borsato, Thaís Teixeira; Berger, Sandrine Bittencourt; Lopes, Murilo Baena; Gonini, Alcides; Sinhoreti, Mário Alexandre Coelho

    2012-01-01

    This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds disinfected with 2% sodium hypochlorite, 2% chlorhexidine digluconate or 0.2% peracetic acid to models produced using molds which were not disinfected, with 3 alginate materials (Cavex ColorChange, Hydrogum 5 and Jeltrate Plus). The molds were prepared over matrix containing 20-, 50-, and 75-µm lines, performed under pressure with perforated metal tray. The molds were removed following gelation and either disinfected (using one of the solutions by spraying followed by storage in closed jars for 15 min) or not disinfected. The samples were divided into 12 groups (n=5). Molds were filled with dental gypsum Durone IV and 1 h after the start of the stone mixing the models were separated from the tray. Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-µm line with 25 mm in length, in accordance with the ISO 1563 standard. The dimensional accuracy results (%) were subjected to ANOVA. The 50 µm-line was completely reproduced by all alginate impression materials regardless of the disinfection procedure. There was no statistically significant difference in the mean values of dimensional accuracy in combinations between disinfectant procedure and alginate impression material (p=0.2130) or for independent factors. The disinfectant solutions and alginate materials used in this study are no factors of choice regarding the surface detail reproduction and dimensional accuracy of stone models.

  2. Messier: A Detailed NVM-Based DIMM Model for the SST Simulation Framework.

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Amro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Voskuilen, Gwendolyn Renae [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rodrigues, Arun F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Simon David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoekstra, Robert J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hughes, Clayton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    DRAM technology is the main building block of main memory, however, DRAM scaling is becoming very challenging. The main issues for DRAM scaling are the increasing error rates with each new generation, the geometric and physical constraints of scaling the capacitor part of the DRAM cells, and the high power consumption caused by the continuous need for refreshing cell values. At the same time, emerging Non- Volatile Memory (NVM) technologies, such as Phase-Change Memory (PCM), are emerging as promising replacements for DRAM. NVMs, when compared to current technologies e.g., NAND-based ash, have latencies comparable to DRAM. Additionally, NVMs are non-volatile, which eliminates the need for refresh power and enables persistent memory applications. Finally, NVMs have promising densities and the potential for multi-level cell (MLC) storage.

  3. A Structural Equation Model of Expertise in College Physics

    Science.gov (United States)

    Taasoobshirazi, Gita; Carr, Martha

    2009-01-01

    A model of expertise in physics was tested on a sample of 374 college students in 2 different level physics courses. Structural equation modeling was used to test hypothesized relationships among variables linked to expert performance in physics including strategy use, pictorial representation, categorization skills, and motivation, and these…

  4. A Structural Equation Model of Conceptual Change in Physics

    Science.gov (United States)

    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…

  5. Modeling detailed hydro-meteorological surfaces and runoff response in large diverse watersheds

    International Nuclear Information System (INIS)

    Byrne, J.; Kienzle, S.W.; MacDonald, R.J.

    2008-01-01

    An understanding of local variability in climatic conditions over complex terrain is imperative to making accurate assessments of impacts from climate change on fresh water ecosystems (Daly, 2006). The derivation of representative spatial data in diverse environments poses a significant challenge to the modelling community. This presentation describes the current status of a long term ongoing hydro-climate model development program. We are developing a gridded hydroclimate dataset for diverse watersheds using SimGrid (Larson, 2008; Lapp et al., 2005; Sheppard, 1996), a model that applies the Mountain Climate Model (MTCLIM; Hungerford et al., 1989) to simulate hydro-climatic conditions over diverse terrain. The model uses GIS based terrain categories (TC) classified by slope, aspect, elevation, and soil water storage. SimGrid provides daily estimates of solar radiation, air temperature, relative humidity, precipitation, snowpack and soil water storage over space. Earlier versions of the model have been applied in the St. Mary (Larson, 2008) and upper Oldman basins (Lapp et al., 2005), giving realistic estimates of hydro-climatic variables. The current study demonstrates improvements to the estimation of temperature, precipitation, snowpack, soil water storage and runoff from the basin. Soil water storage data for the upper drainage were derived with GIS and included in SimGrid to estimate soil water flux over the time period. These changes help improve the estimation of spatial climatic variability over the basin while accounting for topographical influence. In further work we will apply spatial hydro-climatic surfaces from the SimGrid model to assess the hydrologic response to environmental change for watersheds in Canada and beyond. (author)

  6. Development and validation of a detailed TRNSYS-Matlab model for large solar collector fields for district heating applications

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon

    2017-01-01

    This study describes the development of a detailed TRNSYS-Matlab model to simulate the behavior of a large solar collector field for district heating application. The model includes and investigates aspects which are not always considered by simpler models, such as flow distribution...... programming and computing time. Thermal capacity was worth being considered only for the bulkier components, such as the longer distribution and transmission pipes. The actual control strategy, which regulates the flow rates in the solar heating plant, was accurately reproduced in the model, as proved...... in the different rows, effect of the flow regime on the collector efficiency, thermal capacity of the components and effect of shadows from row to row. The model was compared with measurements from a solar collector field and the impact of each aspect was evaluated. A good agreement between model and measurements...

  7. Investigating conceptual models for physical property couplings in solid solution models of cement

    International Nuclear Information System (INIS)

    Benbow, Steven; Watson, Claire; Savage, David

    2005-11-01

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste

  8. Investigating conceptual models for physical property couplings in solid solution models of cement

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Watson, Claire; Savage, David [Quintesssa Ltd., Henley-on-Thames (United Kingdom)

    2005-11-15

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste.

  9. Author Details

    African Journals Online (AJOL)

    Gillah, PR. Vol 77, No 1 (2008) - Articles Some Physical And Strength Properties Of Lesser Known Aphloia theiformis Timber From Lushoto Tanga, Tanzania Abstract · Vol 77, No 1 (2008) - Articles Physical and strength properties of Azadirachta indica, (a. Juss.) growing in Morogoro, Tanzania Abstract · Vol 79, No 1 (2009) ...

  10. Author Details

    African Journals Online (AJOL)

    Physical fitness and the physical activity status of 15-year-old adolescents in a ... jump in 10-15 year old girls from disadvantaged communities in South Africa ... characteristics of stunted and non-stunted black South African boys living in a ...

  11. Author Details

    African Journals Online (AJOL)

    Perceived benefits and barriers to physical exercise participation of first year university students. Abstract · 2011: ... Participation in physical activity: An empirical study of undergraduate university students' perceptions ... Perceived stress and coping skills of university student-athletes and the relationship with life satisfaction

  12. Author Details

    African Journals Online (AJOL)

    Level 100 Physics' students' experiences and perceptions with interactive engagement approaches in teaching: a study in a Ghanaian University Abstract PDF · Vol 9, No 1 (2011) - Articles Level 100 Physics' students' experiences and perceptions with interactive engagement approaches in teaching: a study in a Ghanaian ...

  13. Author Details

    African Journals Online (AJOL)

    ... Patients in Cambodia, Myanmar and Vietnam Abstract · Vol 22, No 3:1 (2016) - Articles Physical inactivity and associated factors in chronic disease patients in Cambodia, Myanmar and Vietnam Abstract · Vol 23, No 1:2 (2017) - Articles Health-enhancing physical activity among university students in nine ASEAN countries

  14. A Contribution to Nyquist-Rate ADC Modeling - Detailed Algorithm Description

    Directory of Open Access Journals (Sweden)

    J. Zidek

    2012-04-01

    Full Text Available In this article, the innovative ADC modeling algorithm is described. It is well suitable for nyquist-rate ADC error back annotation. This algorithm is the next step of building a support tool for IC design engineers. The inspiration for us was the work [2]. Here, the ADC behavior is divided into HCF (High Code Frequency and LCF (Low Code Frequency separated independent parts. This paper is based on the same concept but the model coefficients are estimated in a different way only from INL data. The HCF order recognition part was newly added as well. Thanks to that the HCF coefficients number is lower in comparison with the original Grimaldi’s work (especially for converters with low ratio between HCF and “random” part of INL. Modeling results are demonstrated on a real data set measured by ASICentrum on chargeredistribution type SAR ADC chip. Results are showed not only by coefficient values but also by the Model Coverage metrics. Model limitations are also discussed.

  15. Assessing the operation rules of a reservoir system based on a detailed modelling-chain

    Science.gov (United States)

    Bruwier, M.; Erpicum, S.; Pirotton, M.; Archambeau, P.; Dewals, B.

    2014-09-01

    According to available climate change scenarios for Belgium, drier summers and wetter winters are expected. In this study, we focus on two muti-purpose reservoirs located in the Vesdre catchment, which is part of the Meuse basin. The current operation rules of the reservoirs are first analysed. Next, the impacts of two climate change scenarios are assessed and enhanced operation rules are proposed to mitigate these impacts. For this purpose, an integrated model of the catchment was used. It includes a hydrological model, one-dimensional and two-dimensional hydraulic models of the river and its main tributaries, a model of the reservoir system and a flood damage model. Five performance indicators of the reservoir system have been defined, reflecting its ability to provide sufficient drinking, to control floods, to produce hydropower and to reduce low-flow condition. As shown by the results, enhanced operation rules may improve the drinking water potential and the low-flow augmentation while the existing operation rules are efficient for flood control and for hydropower production.

  16. Assessing the operation rules of a reservoir system based on a detailed modelling chain

    Science.gov (United States)

    Bruwier, M.; Erpicum, S.; Pirotton, M.; Archambeau, P.; Dewals, B. J.

    2015-03-01

    According to available climate change scenarios for Belgium, drier summers and wetter winters are expected. In this study, we focus on two multi-purpose reservoirs located in the Vesdre catchment, which is part of the Meuse basin. The current operation rules of the reservoirs are first analysed. Next, the impacts of two climate change scenarios are assessed and enhanced operation rules are proposed to mitigate these impacts. For this purpose, an integrated model of the catchment was used. It includes a hydrological model, one-dimensional and two-dimensional hydraulic models of the river and its main tributaries, a model of the reservoir system and a flood damage model. Five performance indicators of the reservoir system have been defined, reflecting its ability to provide sufficient drinking water, to control floods, to produce hydropower and to reduce low-flow conditions. As shown by the results, enhanced operation rules may improve the drinking water potential and the low-flow augmentation while the existing operation rules are efficient for flood control and for hydropower production.

  17. The effect of a loss of model structural detail due to network skeletonization on contamination warning system design: case studies

    Science.gov (United States)

    Davis, Michael J.; Janke, Robert

    2018-05-01

    The effect of limitations in the structural detail available in a network model on contamination warning system (CWS) design was examined in case studies using the original and skeletonized network models for two water distribution systems (WDSs). The skeletonized models were used as proxies for incomplete network models. CWS designs were developed by optimizing sensor placements for worst-case and mean-case contamination events. Designs developed using the skeletonized network models were transplanted into the original network model for evaluation. CWS performance was defined as the number of people who ingest more than some quantity of a contaminant in tap water before the CWS detects the presence of contamination. Lack of structural detail in a network model can result in CWS designs that (1) provide considerably less protection against worst-case contamination events than that obtained when a more complete network model is available and (2) yield substantial underestimates of the consequences associated with a contamination event. Nevertheless, CWSs developed using skeletonized network models can provide useful reductions in consequences for contaminants whose effects are not localized near the injection location. Mean-case designs can yield worst-case performances similar to those for worst-case designs when there is uncertainty in the network model. Improvements in network models for WDSs have the potential to yield significant improvements in CWS designs as well as more realistic evaluations of those designs. Although such improvements would be expected to yield improved CWS performance, the expected improvements in CWS performance have not been quantified previously. The results presented here should be useful to those responsible for the design or implementation of CWSs, particularly managers and engineers in water utilities, and encourage the development of improved network models.

  18. Detailed modeling of size distribution functions and hydrogen content in combustion-formed particles

    Energy Technology Data Exchange (ETDEWEB)

    Sirignano, Mariano; D' Anna, Andrea [Dipartimento di Ingegneria Chimica, Universita di Napoli ' ' Federico II' ' , Napoli (Italy); Kent, John [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney (Australia)

    2010-06-15

    A kinetic modeling approach is proposed to delve into the nature and chemistry of combustion-produced particles. A sectional method is used for the first time on this purpose. It is based on modeling of gas-to-particle transitions by sections containing 125 lumped species with C numbers ranging from 24 to 4 x 10{sup 8} and H/C ratio ranging from 0 to 1. This allows not only the mass evolution of particles, but also their hydrogen content to be followed. The model is tested in an atmospheric pressure premixed flat flame of ethylene/oxygen with C/O = 0.8 and cold gas flow velocity of 4 cm/s. Comparison of modeled results with experimental data is satisfying in terms of species concentrations and H/C ratio of the particles. Analysis of model results in comparison with the experimental data has shown that it is possible to distinguish different precursors of particles moving from the exit of the burner into the post-oxidation region of the flame. At particle inception, i.e. just downstream from the flame front, gas-phase PAHs are responsible for particle nucleation and oligomers of aromatic hydrocarbons and small pericondensed hydrocarbons are predominantly present. Then the dehydrogenation process takes place and soot formation starts; in this zone large pericondensed and stacked structures are produced. Further up soot maturation generally linked with dehydrogenation is present, but still a few particles with higher H/C and with low coagulation efficiency are produced and remain present along the flame. The model, in accordance with experimental structural soot analysis, shows that in soot particles condensed structures typical of clusters of large pericondensed hydrocarbons are present whereas high-molecular mass condensed species mainly comprise oligomers of small aromatic compounds of clusters of small pericondensed hydrocarbons. (author)

  19. From Detailed Description of Chemical Reacting Carbon Particles to Subgrid Models for CFD

    Directory of Open Access Journals (Sweden)

    Schulze S.

    2013-04-01

    Full Text Available This work is devoted to the development and validation of a sub-model for the partial oxidation of a spherical char particle moving in an air/steam atmosphere. The particle diameter is 2 mm. The coal particle is represented by moisture- and ash-free nonporous carbon while the coal rank is implemented using semi-global reaction rate expressions taken from the literature. The submodel includes six gaseous chemical species (O2, CO2, CO, H2O, H2, N2. Three heterogeneous reactions are employed, along with two homogeneous semi-global reactions, namely carbon monoxide oxidation and the water-gas-shift reaction. The distinguishing feature of the subgrid model is that it takes into account the influence of homogeneous reactions on integral characteristics such as carbon combustion rates and particle temperature. The sub-model was validated by comparing its results with a comprehensive CFD-based model resolving the issues of bulk flow and boundary layer around the particle. In this model, the Navier-Stokes equations coupled with the energy and species conservation equations were used to solve the problem by means of the pseudo-steady state approach. At the surface of the particle, the balance of mass, energy and species concentration was applied including the effect of the Stefan flow and heat loss due to radiation at the surface of the particle. Good agreement was achieved between the sub-model and the CFD-based model. Additionally, the CFD-based model was verified against experimental data published in the literature (Makino et al. (2003 Combust. Flame 132, 743-753. Good agreement was achieved between numerically predicted and experimentally obtained data for input conditions corresponding to the kinetically controlled regime. The maximal discrepancy (10% between the experiments and the numerical results was observed in the diffusion-controlled regime. Finally, we discuss the influence of the Reynolds number, the ambient O2 mass fraction and the ambient

  20. Detailed modelling of the susceptibility of a thermally populated, strongly driven circuit-QED system

    International Nuclear Information System (INIS)

    Kockum, Anton Frisk; Johansson, Göran; Sandberg, Martin; Vissers, Michael R; Gao, Jiansong; Pappas, David P

    2013-01-01

    We present measurements and modelling of the susceptibility of a 2D microstrip cavity coupled to a driven transmon qubit. We are able to fit the response of the cavity to a weak probe signal with high accuracy in the strong coupling, low detuning, i.e., non-dispersive, limit over a wide bandwidth. The observed spectrum is rich in multi-photon processes for the doubly dressed transmon. These features are well explained by including the higher transmon levels in the driven Jaynes–Cummings model and solving the full master equation to calculate the susceptibility of the cavity. (paper)

  1. Application of Physically based landslide susceptibility models in Brazil

    Science.gov (United States)

    Carvalho Vieira, Bianca; Martins, Tiago D.

    2017-04-01

    Shallow landslides and floods are the processes responsible for most material and environmental damages in Brazil. In the last decades, some landslides events induce a high number of deaths (e.g. Over 1000 deaths in one event) and incalculable social and economic losses. Therefore, the prediction of those processes is considered an important tool for land use planning tools. Among different methods the physically based landslide susceptibility models having been widely used in many countries, but in Brazil it is still incipient when compared to other ones, like statistical tools and frequency analyses. Thus, the main objective of this research was to assess the application of some Physically based landslide susceptibility models in Brazil, identifying their main results, the efficiency of susceptibility mapping, parameters used and limitations of the tropical humid environment. In order to achieve that, it was evaluated SHALSTAB, SINMAP and TRIGRS models in some studies in Brazil along with the Geotechnical values, scales, DEM grid resolution and the results based on the analysis of the agreement between predicted susceptibility and the landslide scar's map. Most of the studies in Brazil applied SHALSTAB, SINMAP and to a lesser extent the TRIGRS model. The majority researches are concentrated in the Serra do Mar mountain range, that is a system of escarpments and rugged mountains that extends more than 1,500 km along the southern and southeastern Brazilian coast, and regularly affected by heavy rainfall that generates widespread mass movements. Most part of these studies used conventional topographic maps with scales ranging from 1:2000 to 1:50000 and DEM-grid resolution between 2 and 20m. Regarding the Geotechnical and hydrological values, a few studies use field collected data which could produce more efficient results, as indicated by international literature. Therefore, even though they have enormous potential in the susceptibility mapping, even for comparison

  2. Application of Detailed Phase Comparison Protection Models for the Analysis of its Operation in Networks with Facts Devices

    Directory of Open Access Journals (Sweden)

    Ruban Nikolay Yu.

    2015-01-01

    Full Text Available The problem of relay protection misoperations in networks with FACTS devices is considered in the paper. It is offered a solution to this problem for a phase comparison protection of transmission power line through the use of its detailed model for the analysis of the functioning for a case of various normal, emergency and post-emergency modes of electric power systems. The research results of this approach are given in the paper.

  3. Inverse modeling of cloud-aerosol interactions -- Part 1: Detailed response surface analysis

    NARCIS (Netherlands)

    Partridge, D.G.; Vrugt, J.A.; Tunved, P.; Ekman, A.M.L.; Gorea, D.; Sooroshian, A.

    2011-01-01

    New methodologies are required to probe the sensitivity of parameters describing cloud droplet activation. This paper presents an inverse modeling-based method for exploring cloud-aerosol interactions via response surfaces. The objective function, containing the difference between the measured and

  4. Detailed Equivalent VSC-HVDC Modelling for Time Domain Harmonic Stability Studies in Wind Power Plants

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Bak, Claus Leth; Kocewiak, Lukasz Hubert

    2018-01-01

    system with 201 voltage levels, without loss of accuracy compared to conventional modelling of the converter. Harmonic stability is a core concern for both existing and future offshore wind power plants (OWPPs). A harmonic stability study will be undertaken with focus on the number of wind turbine...

  5. DETAILED CHEMICAL KINETIC MODELING OF ISO-OCTANE SI-HCCI TRANSITION

    Energy Technology Data Exchange (ETDEWEB)

    Havstad, M A; Aceves, S M; McNenly, M J; Piggott, W T; Edwards, K D; Wagner, R M; Daw, C S; Finney, C A

    2009-10-12

    The authors describe a CHEMKIN-based multi-zone model that simulates the expected combustion variations in a single-cylinder engine fueled with iso-octane as the engine transitions from spark-ignited (ST) combustion to homogeneous charge compression ignition (HCCI) combustion. The model includes a 63-species reaction mechanism and mass and energy balances for the cylinder and the exhaust flow. For this study they assumed that the SI-to-HCCI transition is implemented by means of increasing the internal exhaust gas recirculation (EGR) at constant engine speed. This transition scneario is consistent with that implemented in previously reported experimental measurements on an experimental engine equipped with variable valve actuation. They find that the model captures many of the important experimental trends, including stable SI combustion at low EGR ({approx} 0.10), a transition to highly unstable combustion at intermediate EGR, and finally stable HCCI combustion at very high EGR ({approx} 0.75). Remaining differences between the predicted and experimental instability patterns indicate that there is further room for model improvement.

  6. Detailed dynamic model for semiconductor optical amplifiers and their crosstalk and intermodulation distortion

    DEFF Research Database (Denmark)

    Durhuus, Terji; Mikkelsen, Benny; Stubkjær, Kristian

    1992-01-01

    . The model is used to assess intermodulation distortion and crosstalk. Cascaded amplifiers are considered, and the crosstalk and intermodulation distortion due to cascaded amplifiers are found to accumulate by adding together in amplitude; this may limit the number or cascaded amplifiers in multichannel...

  7. A detailed model for simulation of catchment scale subsurface hydrologic processes

    Science.gov (United States)

    Paniconi, Claudio; Wood, Eric F.

    1993-01-01

    A catchment scale numerical model is developed based on the three-dimensional transient Richards equation describing fluid flow in variably saturated porous media. The model is designed to take advantage of digital elevation data bases and of information extracted from these data bases by topographic analysis. The practical application of the model is demonstrated in simulations of a small subcatchment of the Konza Prairie reserve near Manhattan, Kansas. In a preliminary investigation of computational issues related to model resolution, we obtain satisfactory numerical results using large aspect ratios, suggesting that horizontal grid dimensions may not be unreasonably constrained by the typically much smaller vertical length scale of a catchment and by vertical discretization requirements. Additional tests are needed to examine the effects of numerical constraints and parameter heterogeneity in determining acceptable grid aspect ratios. In other simulations we attempt to match the observed streamflow response of the catchment, and we point out the small contribution of the streamflow component to the overall water balance of the catchment.

  8. Accuracy assessment of modeling architectural structures and details using terrestrial laser scanning

    Directory of Open Access Journals (Sweden)

    M. Kedzierski

    2015-08-01

    Full Text Available One of the most important aspects when performing architectural documentation of cultural heritage structures is the accuracy of both the data and the products which are generated from these data: documentation in the form of 3D models or vector drawings. The paper describes an assessment of the accuracy of modelling data acquired using a terrestrial phase scanner in relation to the density of a point cloud representing the surface of different types of construction materials typical for cultural heritage structures. This analysis includes the impact of the scanning geometry: the incidence angle of the laser beam and the scanning distance. For the purposes of this research, a test field consisting of samples of different types of construction materials (brick, wood, plastic, plaster, a ceramic tile, sheet metal was built. The study involved conducting measurements at different angles and from a range of distances for chosen scanning densities. Data, acquired in the form of point clouds, were then filtered and modelled. An accuracy assessment of the 3D model was conducted by fitting it with the point cloud. The reflection intensity of each type of material was also analyzed, trying to determine which construction materials have the highest reflectance coefficients, and which have the lowest reflection coefficients, and in turn how this variable changes for different scanning parameters. Additionally measurements were taken of a fragment of a building in order to compare the results obtained in laboratory conditions, with those taken in field conditions.

  9. Detailed modeling of electron emission for transpiration cooling of hypersonic vehicles

    Science.gov (United States)

    Hanquist, Kyle M.; Hara, Kentaro; Boyd, Iain D.

    2017-02-01

    Electron transpiration cooling (ETC) is a recently proposed approach to manage the high heating loads experienced at the sharp leading edges of hypersonic vehicles. Computational fluid dynamics (CFD) can be used to investigate the feasibility of ETC in a hypersonic environment. A modeling approach is presented for ETC, which includes developing the boundary conditions for electron emission from the surface, accounting for the space-charge limit effects of the near-wall plasma sheath. The space-charge limit models are assessed using 1D direct-kinetic plasma sheath simulations, taking into account the thermionically emitted electrons from the surface. The simulations agree well with the space-charge limit theory proposed by Takamura et al. for emitted electrons with a finite temperature, especially at low values of wall bias, which validates the use of the theoretical model for the hypersonic CFD code. The CFD code with the analytical sheath models is then used for a test case typical of a leading edge radius in a hypersonic flight environment. The CFD results show that ETC can lower the surface temperature of sharp leading edges of hypersonic vehicles, especially at higher velocities, due to the increase in ionized species enabling higher electron heat extraction from the surface. The CFD results also show that space-charge limit effects can limit the ETC reduction of surface temperatures, in comparison to thermionic emission assuming no effects of the electric field within the sheath.

  10. Class and Home Problems. Modeling an Explosion: The Devil Is in the Details

    Science.gov (United States)

    Hart, Peter W.; Rudie, Alan W.

    2011-01-01

    Within the past 15 years, three North American pulp mills experienced catastrophic equipment failures while using 50 wt% hydrogen peroxide. In two cases, explosions occurred when normal pulp flow was interrupted due to other process problems. To understand the accidents, a kinetic model of alkali-catalyzed decomposition of peroxide was developed.…

  11. Systems biology from micro-organisms to human metabolic diseases: the role of detailed kinetic models.

    Science.gov (United States)

    Bakker, Barbara M; van Eunen, Karen; Jeneson, Jeroen A L; van Riel, Natal A W; Bruggeman, Frank J; Teusink, Bas

    2010-10-01

    Human metabolic diseases are typically network diseases. This holds not only for multifactorial diseases, such as metabolic syndrome or Type 2 diabetes, but even when a single gene defect is the primary cause, where the adaptive response of the entire network determines the severity of disease. The latter may differ between individuals carrying the same mutation. Understanding the adaptive responses of human metabolism naturally requires a systems biology approach. Modelling of metabolic pathways in micro-organisms and some mammalian tissues has yielded many insights, qualitative as well as quantitative, into their control and regulation. Yet, even for a well-known pathway such as glycolysis, precise predictions of metabolite dynamics from experimentally determined enzyme kinetics have been only moderately successful. In the present review, we compare kinetic models of glycolysis in three cell types (African trypanosomes, yeast and skeletal muscle), evaluate their predictive power and identify limitations in our understanding. Although each of these models has its own merits and shortcomings, they also share common features. For example, in each case independently measured enzyme kinetic parameters were used as input. Based on these 'lessons from glycolysis', we will discuss how to make best use of kinetic computer models to advance our understanding of human metabolic diseases.

  12. Dynamic Simulation of an Organic Rankine Cycle—Detailed Model of a Kettle Boiler

    Directory of Open Access Journals (Sweden)

    Roberto Pili

    2017-04-01

    Full Text Available Organic Rankine Cycles (ORCs are nowadays a valuable technology to produce electricity from low and medium temperature heat sources, e.g., in geothermal, biomass and waste heat recovery applications. Dynamic simulations can help improve the flexibility and operation of such plants, and guarantee a better economic performance. In this work, a dynamic model for a multi-pass kettle evaporator of a geothermal ORC power plant has been developed and its dynamics have been validated against measured data. The model combines the finite volume approach on the tube side and a two-volume cavity on the shell side. To validate the dynamic model, a positive and a negative step function in heat source flow rate is applied. The simulation model performed well in both cases. The liquid level appeared the most challenging quantity to simulate. A better agreement in temperature was achieved by increasing the volume flow rate of the geothermal brine by 2% over the entire simulation. Measurement errors, discrepancies in working fluid and thermal brine properties and uncertainties in heat transfer correlations can account for this. In the future, the entire geothermal power plant will be simulated, and suggestions to improve its dynamics and control by means of simulations will be provided.

  13. Details Matter: Noise and Model Structure Set the Relationship between Cell Size and Cell Cycle Timing

    Directory of Open Access Journals (Sweden)

    Felix Barber

    2017-11-01

    Full Text Available Organisms across all domains of life regulate the size of their cells. However, the means by which this is done is poorly understood. We study two abstracted “molecular” models for size regulation: inhibitor dilution and initiator accumulation. We apply the models to two settings: bacteria like Escherichia coli, that grow fully before they set a division plane and divide into two equally sized cells, and cells that form a bud early in the cell division cycle, confine new growth to that bud, and divide at the connection between that bud and the mother cell, like the budding yeast Saccharomyces cerevisiae. In budding cells, delaying cell division until buds reach the same size as their mother leads to very weak size control, with average cell size and standard deviation of cell size increasing over time and saturating up to 100-fold higher than those values for cells that divide when the bud is still substantially smaller than its mother. In budding yeast, both inhibitor dilution or initiator accumulation models are consistent with the observation that the daughters of diploid cells add a constant volume before they divide. This “adder” behavior has also been observed in bacteria. We find that in bacteria an inhibitor dilution model produces adder correlations that are not robust to noise in the timing of DNA replication initiation or in the timing from initiation of DNA replication to cell division (the C+D period. In contrast, in bacteria an initiator accumulation model yields robust adder correlations in the regime where noise in the timing of DNA replication initiation is much greater than noise in the C + D period, as reported previously (Ho and Amir, 2015. In bacteria, division into two equally sized cells does not broaden the size distribution.

  14. Dynamic hydraulic models to study sedimentation in drinking water networks in detail

    Directory of Open Access Journals (Sweden)

    I. W. M. Pothof

    2012-12-01

    Full Text Available Sedimentation in drinking water networks can lead to discolouration complaints. A sufficient criterion to prevent sedimentation in the Dutch drinking water networks is a daily maximum velocity of 0.25 m s−1. Flushing experiments have shown that this criterion is a sufficient condition for a clean network, but not a necessary condition. Drinking water networks include many locations with a maximum velocity well below 0.25 m s−1 without accumulated sediments. Other criteria need to be developed to predict which locations are susceptible to sedimentation and to prevent sedimentation in future networks. More distinctive criteria are helpful to prioritise flushing operations and to prevent water quality complaints.

    The authors use three different numerical modelling approaches – quasi-steady, rigid column and water hammer – with a temporal discretisation of 1 s in order to assess the influence of unsteady flows on the wall shear stress, causing resuspension of sediment particles. The model predictions are combined with results from flushing experiments in the drinking water distribution system of Purmerend, the Netherlands. The waterhammer model does not result in essentially different flow distribution patterns, compared to the rigid column and quasi-steady modelling approach. The extra information from the waterhammer model is a velocity oscillation of approximately 0.02 m s−1 around the quasi-steady solution. The presence of stagnation zones and multiple flow direction reversals seem to be interesting new parameters to predict sediment accumulation, which are consistent with the observed turbidity data and theoretical considerations on critical shear stresses.

  15. Physics in the model for a eurobachelor syllabus

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    of the following subjects: Classical mechanics, thermodynamics, quantum mechanics, elementary particles, radiation, fluid dynamics, spectros-copy, diffraction, crystallography, scattering and electromagnetism. Further details, as to the contents and to contemporary principles of pedagogy, will be provided...... of contact (teaching) hours amounts to 75. These hours are devoted to fundamentals of physics that enables the student to understand the principles of functionality of laboratory equipment and allow the student to operate such instruments at the user level. Details of the contents comprise elements...

  16. Influence of alginate impression materials and storage time on surface detail reproduction and dimensional accuracy of stone models.

    Science.gov (United States)

    Guiraldo, Ricardo D; Moreti, Ana F F; Martinelli, Julia; Berger, Sandrine B; Meneghel, Luciana L; Caixeta, Rodrigo V; Sinhoreti, Mário A C

    2015-01-01

    This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds prepared using different alginate impression materials (Cavex ColorChange, Hydrogum 5, or Jeltrate Plus) and with different storage times (1, 3, and 5 days) to models from molds that were filled immediately with no storage time. The molds were prepared over a matrix containing 50-μm line, (ISO 1563 standard) under pressure with a perforated metal tray. The molds were removed 2 minutes after loss of sticky consistency and either filled immediately or stored in closed jars at 100% relative humidity and 37°C for 1, 3, or 5 days. The molds were filled with dental plaster (Durone IV). Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-μm wide line, which was 25 mm in length, according to ISO 1563 standard. The dimensional accuracy results (%) were subjected to analysis of variance. The 50-μm wide line (ISO 1563 standard) was completely reproduced by all alginate impression materials regardless of the storage time. There was no statistically significant difference in the mean dimensional accuracy values of stone models made from molds composed of different alginate impression materials and with different storage times (p = 0.989). In conclusion, storing the mold for five days prior to filling did not change the surface detail reproduction or dimensional accuracy of the alginates examined in this study.

  17. NSTX Disruption Simulations of Detailed Divertor and Passive Plate Models by Vector Potential Transfer from OPERA Global Analysis Results

    International Nuclear Information System (INIS)

    Titus, P.H.; Avasaralla, S.; Brooks, A.; Hatcher, R.

    2010-01-01

    The National Spherical Torus Experiment (NSTX) project is planning upgrades to the toroidal field, plasma current and pulse length. This involves the replacement of the center-stack, including the inner legs of the TF, OH, and inner PF coils. A second neutral beam will also be added. The increased performance of the upgrade requires qualification of the remaining components including the vessel, passive plates, and divertor for higher disruption loads. The hardware needing qualification is more complex than is typically accessible by large scale electromagnetic (EM) simulations of the plasma disruptions. The usual method is to include simplified representations of components in the large EM models and attempt to extract forces to apply to more detailed models. This paper describes a more efficient approach of combining comprehensive modeling of the plasma and tokamak conducting structures, using the 2D OPERA code, with much more detailed treatment of individual components using ANSYS electromagnetic (EM) and mechanical analysis. This capture local eddy currents and resulting loads in complex details, and allows efficient non-linear, and dynamic structural analyses.

  18. NSTX Disruption Simulations of Detailed Divertor and Passive Plate Models by Vector Potential Transfer from OPERA Global Analysis Results

    Energy Technology Data Exchange (ETDEWEB)

    P. H. Titus, S. Avasaralla, A.Brooks, R. Hatcher

    2010-09-22

    The National Spherical Torus Experiment (NSTX) project is planning upgrades to the toroidal field, plasma current and pulse length. This involves the replacement of the center-stack, including the inner legs of the TF, OH, and inner PF coils. A second neutral beam will also be added. The increased performance of the upgrade requires qualification of the remaining components including the vessel, passive plates, and divertor for higher disruption loads. The hardware needing qualification is more complex than is typically accessible by large scale electromagnetic (EM) simulations of the plasma disruptions. The usual method is to include simplified representations of components in the large EM models and attempt to extract forces to apply to more detailed models. This paper describes a more efficient approach of combining comprehensive modeling of the plasma and tokamak conducting structures, using the 2D OPERA code, with much more detailed treatment of individual components using ANSYS electromagnetic (EM) and mechanical analysis. This capture local eddy currents and resulting loads in complex details, and allows efficient non-linear, and dynamic structural analyses.

  19. Parametric Variation for Detailed Model of External Grid in Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Myagkov, Vladimir; Petersen, Lennart; Laza, Burutxaga

    2014-01-01

    The representation of the external grid impedance is a key element in harmonic studies for offshore wind farms. The external grid impedance is here represented by two different approaches: by a simplified impedance model, based on values for short-circuit power and XR-ratio and by locus diagrams...... for defining a procedure for conducting harmonic studies in wind farms that can be used in commercial project developments....

  20. LFPy: A tool for biophysical simulation of extracellular potentials generated by detailed model neurons

    Directory of Open Access Journals (Sweden)

    Henrik eLindén

    2014-01-01

    Full Text Available Electrical extracellular recordings, i.e., recordings of the electrical potentials in the extracellular medium between cells, have been a main work-horse in electrophysiology for almost a century. The high-frequency part of the signal (>=500 Hz, i.e., themulti-unit activity (MUA, contains information about the firing of action potentials in surrounding neurons, while the low-frequency part, the local field potential (LFP, contains information about how these neurons integrate synaptic inputs. As the recorded extracellular signals arise from multiple neural processes, their interpretation is typically ambiguous and difficult. Fortunately, a precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established: the extracellular potential can be calculated as a weighted sum of all transmembrane currents in all cells located in the vicinity of the electrode. This computational scheme can considerably aid the modeling and analysis of MUA and LFP signals.Here, we describe LFPy, an open source Python package for numerical simulations of extracellular potentials. LFPy consists of a set of easy-to-use classes for defining cells, synapses and recording electrodes as Python objects, implementing this biophysical modeling scheme. It runs on top of the widely used NEURON simulation environment, which allows for flexible usage of both new and existing cell models.Further, calculation of extracellular potentials using the line-source-method is efficiently implemented.We describe the theoretical framework underlying the extracellular potential calculations and illustrate by examples how LFPy can be used both for simulating LFPs, i.e., synaptic contributions from single cells as well a populations of cells, and MUAs, i.e., extracellular signatures of action potentials.

  1. LFPy: a tool for biophysical simulation of extracellular potentials generated by detailed model neurons.

    Science.gov (United States)

    Lindén, Henrik; Hagen, Espen; Lęski, Szymon; Norheim, Eivind S; Pettersen, Klas H; Einevoll, Gaute T

    2013-01-01

    Electrical extracellular recordings, i.e., recordings of the electrical potentials in the extracellular medium between cells, have been a main work-horse in electrophysiology for almost a century. The high-frequency part of the signal (≳500 Hz), i.e., the multi-unit activity (MUA), contains information about the firing of action potentials in surrounding neurons, while the low-frequency part, the local field potential (LFP), contains information about how these neurons integrate synaptic inputs. As the recorded extracellular signals arise from multiple neural processes, their interpretation is typically ambiguous and difficult. Fortunately, a precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established: the extracellular potential can be calculated as a weighted sum of all transmembrane currents in all cells located in the vicinity of the electrode. This computational scheme can considerably aid the modeling and analysis of MUA and LFP signals. Here, we describe LFPy, an open source Python package for numerical simulations of extracellular potentials. LFPy consists of a set of easy-to-use classes for defining cells, synapses and recording electrodes as Python objects, implementing this biophysical modeling scheme. It runs on top of the widely used NEURON simulation environment, which allows for flexible usage of both new and existing cell models. Further, calculation of extracellular potentials using the line-source-method is efficiently implemented. We describe the theoretical framework underlying the extracellular potential calculations and illustrate by examples how LFPy can be used both for simulating LFPs, i.e., synaptic contributions from single cells as well a populations of cells, and MUAs, i.e., extracellular signatures of action potentials.

  2. Detection of Earth impact craters aided by the detailed global gravitational model EGM2008

    Czech Academy of Sciences Publication Activity Database

    Klokočník, Jaroslav; Kostelecký, J.; Novák, P.; Wagner, C. A.

    2010-01-01

    Roč. 7, č. 1 (2010), s. 71-97 ISSN 1214-9705 R&D Projects: GA MŠk(CZ) LC506 Grant - others:ESA(XE) ESA- PECS project No.98056 Institutional research plan: CEZ:AV0Z10030501 Keywords : global gravitational model * gravity anomaly * impact craters on the Earth Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.452, year: 2010

  3. Modeling market power in electricity markets: Is the devil only in the details?

    Energy Technology Data Exchange (ETDEWEB)

    Bautista, Guillermo; Anjos, Miguel F.; Vannelli, Anthony

    2007-01-15

    Basic approximations of the transmission system are ubiquitous in the literature on modeling competition in electricity markets. Because the main concern of market power is with active power, reactive power and voltage-related issues are commonly neglected, even though they are inherent features of an electrical power system. However, the usefulness of stylized formulations that do not comprise these system elements may be severely limited. (author)

  4. Ice formation in altocumulus clouds over Leipzig: Remote sensing measurements and detailed model simulations

    Science.gov (United States)

    Simmel, Martin; Bühl, Johannes; Ansmann, Albert; Tegen, Ina

    2014-05-01

    Over Leipzig, altocumulus clouds are frequently observed using a suite of remote sensing instruments. These observations cover a wide range of heights, temperatures, and microphysical properties of the clouds ranging from purely liquid to heavily frozen. For the current study, two cases were chosen to test the sensitivity of these clouds with respect to several microphysical and dynamical parameters such as aerosol properties (CCN, IN), ice particle shape as well as turbulence. The mixed-phase spectral microphysical model SPECS was coupled to a dynamical model of the Asai-Kasahara type resulting in the model system AK-SPECS. The relatively simple dynamics allows for a fine vertical resolution needed for the rather shallow cloud layers observed. Additionally, the proper description of hydrometeor sedimentation is important especially for the fast growing ice crystals to realistically capture their interaction with the vapour and liquid phase (Bergeron-Findeisen process). Since the focus is on the cloud microphysics, the dynamics in terms of vertical velocity profile is prescribed for the model runs and the feedback of the microphysics on dynamics by release or consumption of latent heat due to phase transfer is not taken into account. The microphysics focuses on (1) ice particle shape allowing hexagonal plates and columns with size-dependant axis ratios and (2) the ice nuclei (IN) budget realized with a prognostic temperature resolved field of potential IN allowing immersion freezing only when active IN and supercooled drops above a certain size threshold are present within a grid cell. Sensitivity studies show for both cases that ice particle shape seems to have the major influence on ice mass formation under otherwise identical conditions. This is due to the effect (1) on terminal fall velocity of the individual ice particle allowing for longer presence times in conditions supersaturated with respect to ice and (2) on water vapour deposition which is enhanced due

  5. Mathematical modeling provides kinetic details of the human immune response to vaccination

    Directory of Open Access Journals (Sweden)

    Dustin eLe

    2015-01-01

    Full Text Available With major advances in experimental techniques to track antigen-specific immune responses many basic questions on the kinetics of virus-specific immunity in humans remain unanswered. To gain insights into kinetics of T and B cell responses in human volunteers we combine mathematical models and experimental data from recent studies employing vaccines against yellow fever and smallpox. Yellow fever virus-specific CD8 T cell population expanded slowly with the average doubling time of 2 days peaking 2.5 weeks post immunization. Interestingly, we found that the peak of the yellow fever-specific CD8 T cell response is determined by the rate of T cell proliferation and not by the precursor frequency of antigen-specific cells as has been suggested in several studies in mice. We also found that while the frequency of virus-specific T cells increases slowly, the slow increase can still accurately explain clearance of yellow fever virus in the blood. Our additional mathematical model describes well the kinetics of virus-specific antibody-secreting cell and antibody response to vaccinia virus in vaccinated individuals suggesting that most of antibodies in 3 months post immunization are derived from the population of circulating antibody-secreting cells. Taken together, our analysis provides novel insights into mechanisms by which live vaccines induce immunity to viral infections and highlight challenges of applying methods of mathematical modeling to the current, state-of-the-art yet limited immunological data.

  6. Mathematical modeling provides kinetic details of the human immune response to vaccination.

    Science.gov (United States)

    Le, Dustin; Miller, Joseph D; Ganusov, Vitaly V

    2014-01-01

    With major advances in experimental techniques to track antigen-specific immune responses many basic questions on the kinetics of virus-specific immunity in humans remain unanswered. To gain insights into kinetics of T and B cell responses in human volunteers we combined mathematical models and experimental data from recent studies employing vaccines against yellow fever and smallpox. Yellow fever virus-specific CD8 T cell population expanded slowly with the average doubling time of 2 days peaking 2.5 weeks post immunization. Interestingly, we found that the peak of the yellow fever-specific CD8 T cell response was determined by the rate of T cell proliferation and not by the precursor frequency of antigen-specific cells as has been suggested in several studies in mice. We also found that while the frequency of virus-specific T cells increased slowly, the slow increase could still accurately explain clearance of yellow fever virus in the blood. Our additional mathematical model described well the kinetics of virus-specific antibody-secreting cell and antibody response to vaccinia virus in vaccinated individuals suggesting that most of antibodies in 3 months post immunization were derived from the population of circulating antibody-secreting cells. Taken together, our analysis provided novel insights into mechanisms by which live vaccines induce immunity to viral infections and highlighted challenges of applying methods of mathematical modeling to the current, state-of-the-art yet limited immunological data.

  7. Detailed Urban Heat Island Projections for Cities Worldwide: Dynamical Downscaling CMIP5 Global Climate Models

    Directory of Open Access Journals (Sweden)

    Dirk Lauwaet

    2015-06-01

    Full Text Available A new dynamical downscaling methodology to analyze the impact of global climate change on the local climate of cities worldwide is presented. The urban boundary layer climate model UrbClim is coupled to 11 global climate models contained in the Coupled Model Intercomparison Project 5 archive, conducting 20-year simulations for present (1986–2005 and future (2081–2100 climate conditions, considering the Representative Concentration Pathway 8.5 climate scenario. The evolution of the urban heat island of eight different cities, located on three continents, is quantified and assessed, with an unprecedented horizontal resolution of a few hundred meters. For all cities, urban and rural air temperatures are found to increase strongly, up to 7 °C. However, the urban heat island intensity in most cases increases only slightly, often even below the range of uncertainty. A potential explanation, focusing on the role of increased incoming longwave radiation, is put forth. Finally, an alternative method for generating urban climate projections is proposed, combining the ensemble temperature change statistics and the results of the present-day urban climate.

  8. Detailed empirical models for the winds of early-type stars

    International Nuclear Information System (INIS)

    Olson, G.L.; Castor, J.I.

    1981-01-01

    Owing to the recent accumulation of ultraviolet data from the IUE satellite, of X-ray data from the Einstein (HEAO 2) satellite, of visible data from ground based electronic detectors, and of radio data from the Very Large Array (VLA) telescope, it is becoming possible to build much more complete models for the winds of early-type stars. The present work takes the empirical approach of assuming that there exists a coronal region at the base of a cool wind (T/sub e/roughly-equalT/sub eff/). This will be an extension of previous papers by Olson and by Cassinelli and Olson; however, refinements to the model will be presented, and the model will be applied to seven O stars and one BO star. Ionization equilibria are computed to match the line strengths found in UV spectra. The coronal fluxes that are required to produce the observed abundance of O +5 are compared to the X-ray fluxes observed by the Einstein satellite

  9. Four discourse models of physics teacher education

    OpenAIRE

    Larsson, Johanna; Airey, John

    2017-01-01

    In Sweden, as in many other countries, the education of high-school physics teachers is typically carried out in three different environments; the education department, the physics department and school itself during teaching practice. Trainee physics teachers are in the process of building their professional identity as they move between these three environments. Although much has been written about teacher professional identity (see overview in Beijaard, Meijer, & Verloop, 2004) little ...

  10. Author Details

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    Njubi, Francis. Vol 15, No 1 (2001): Media Freedom and Human Rights - Articles New Media, Old Struggles: Pan Africanism, Anti-racism and Information Technology Details. ISSN: 0256-004. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Radwan M.D, Mona Ahmed. Vol 12, No 1 (2000) - Articles RELAPSING REMITTING MULTIPLE SCLEROSIS: CT AND MRI IMAGING VS CLINICAL FINDINGIN THE DIAGNOSIS AND DETERMINATION OF DISEASE ACTIVITY. Details. ISSN: 1110-5607. AJOL African Journals Online. HOW TO USE AJOL... for Researchers ...

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    Comarof, Jean. Vol 1999, No 3-4 (1999) - Articles Alien-Nation: Zombies, Immigrants and Millennial Capitalism Details. ISSN: 0850-8712. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact ...

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    NENTY, N. JOHNSON. Vol 7, No 3 (2001) - Articles Common errors and perfomance of students in junior secondary mathematics certificate examinations in Cross River State, Nigeria Details PDF. ISSN: 1118-0579. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

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    A Preliminary Investigation of Relative Frequency of Undiagnosed and Previously Diagnosed Hypertension Before First Stroke in a Lagos Hospital Abstract · Vol 9, No 4 (1999) - Articles Localised tetanus in Lagos, Nigeria Details · Vol 9, No 4 (1999) - Articles Stroke with localised infarction of Wernicke's Area misdiagnosed ...

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    SAMA, G. Vol 2 (2002): Supplement - Articles A Longitudinal Study of the Role of T Cell subset, Th1/Th2 cytokines and antiplasmodial antibodies in uncomplicated Malaria in a Village Population Chronically Exposed to Plasmodium falciparum Malaria. Details PDF · AJOL African Journals Online. HOW TO USE AJOL.

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    QUAKYI, A.I.. Vol 2 (2002): Supplement - Articles A Longitudinal Study of the Role of T Cell subset, Th1/Th2 cytokines and antiplasmodial antibodies in uncomplicated Malaria in a Village Population Chronically Exposed to Plasmodium falciparum Malaria. Details PDF · AJOL African Journals Online. HOW TO USE AJOL.

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    KOUONTCHOU, Samuel. Vol 2 (2002): Supplement - Articles Prevalence of Multiple Concomitant Intestinal Parasitic Infections in Simbok a Malaria Endemic Village in Cameroon. Details PDF · Vol 2 (2002): Supplement - Articles A Longitudinal Study of the Role of T Cell subset, Th1/Th2 cytokines and antiplasmodial ...

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    ALAKE, J. Vol 2 (2002): Supplement - Articles A Longitudinal Study of the Role of T Cell subset, Th1/Th2 cytokines and antiplasmodial antibodies in uncomplicated Malaria in a Village Population Chronically Exposed to Plasmodium falciparum Malaria. Details PDF · AJOL African Journals Online. HOW TO USE AJOL.

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    Rakotonirina, Alice. Vol 2, No 2 (2002) - Articles Effect of the decoction of rhizomes of Cyperus articulatus on bicuculline-, N-methyl-D-aspartate- and strychnine-induced behavioural excitation and convulsions in mice. Details PDF · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

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    Love, Alison. Vol 29, No 2 (2002) - Articles Policy-makers, the Press and Politics: Reporting a Public Policy Document Details. ISSN: 0379-0622. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

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    Focho, DA. Vol 2, No 1 (2002) - Articles Observations on the Meiotic Process in the African Pest Grasshopper Taphronota thaelephora Stal. (Orthoptera : Pyrgomorphidae) Details PDF · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Idowu, OO. Vol 8, No 1 (2003) - Articles Evaluation of Different Substrates and Combinations on the Growth of Pleurotus pulmonarius (Fries) Quelet (Sajor-caju) Details. ISSN: 1118-2733. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Ligthelm, A.A.. Vol 5, No 2 (2001) - Articles Community attitudes towards Casinos and the estimated magnitude of problem gambling The Mpumalanga case. Details PDF. ISSN: 1027-4332. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Kioni, P N. Vol 9, No 1 (2007) - Articles Detailed structure of pipe flow with water hammer oscillations. Abstract. ISSN: 1561-7645. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

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    Development of a trap to contaminate variegated grasshoppers (Zonocerus variegatus L.) (Orthoptera: Pyrgomorphidae) with Metarrhyzium flavo-viride Gams & Rozsypal in the field. Details · Vol 40, No 1 (2007) - Articles Yam pests in the Ashanti and Brong Ahafo regions of Ghana: A study of farmers\\' indigenous technical ...

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    Brown, Duncan. Vol 16, No 2 (2002): Continental Africans & the Question of Identity - Articles Environment and Identity: Douglas Livingstone's A Littoral Zone Details. ISSN: 0256-004. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Aderinokun, GA. Vol 9, No 1 (1999) - Articles Relative Influence Of Sociodemographic Variables On Oral Health And Habits Of Some Nigerian School Children Abstract · Vol 9, No 4 (1999) - Articles Oral health services in Nigeria Details. ISSN: 0189-2657. AJOL African Journals Online. HOW TO USE AJOL.

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    EKPA, O. D.. Vol 7, No 2 (2001) - Articles Variental differences AND polymorphism in palm oil: a case study of palm oils blended with coconut oil. Details PDF. ISSN: 1118-0579. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

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    SONUGA, F A. Vol 6, No 1 (2000) - Articles Geophysical investigation of Karkarku earthdam embankment. Details. ISSN: 1118-0579. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

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    Geotechnical properties of lateritic soil developed over quartz schist in Ishara area, south western Nigeria Details · Vol 44, No 1 (2008) - Articles Comparative study of the influence of cement and lime stabilization on geotechnical properties of lateritic soil derived from pegmatite in Ago-Iwoye area, southwestern Nigeria

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    McCarthy, Greg. Vol 15, No 1 (2001): Media Freedom and Human Rights - Articles Caught between Empires: Ambivalence in Australian Films Details. ISSN: 0256-004. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    Legwaila, GM. Vol 12 (2003) - Articles Review of sweet sorghum: a potential cash and forage crop in Botswana Details. ISSN: 1021-0873. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact ...

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    Admasu, Assefa. Vol 22, No 2 (1999) - Articles Preliminary evaluation of Phytomyza orobanchia (Diptera: Agromyzidae) as a controller of Orobanche spp in Ethiopia Details PDF. ISSN: 2520–7997. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

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    Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Okeke, EO. Vol 10 (2006) - Articles Analysis of Stokes waves theory as a diffusion problem. Abstract · Vol 11 (2007) - Articles On the impact of wave-current on Stokes waves. Abstract. ISSN: 1116-4336. AJOL African ...

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    Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Obtaining the green's function for electromagnetic waves propagating in layered in-homogeneous thin film media of spherical particles on a substrate. Abstract · Vol 20, No 2 (2008) - Articles solution growth and ...

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    Journal Home > Advanced Search > Author Details. Log in or Register to get access to full text downloads. ... Vol 8 (2004) - Articles Further on stokes expansions for the finite amplitude water waves. Abstract · Vol 11 (2007) - Articles On the effects of wave steepness on higher order Stokes waves. Abstract. ISSN: 1116-4336.

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    Akum, ZE. Vol 1, No 3 (2001) - Articles Basic home range characteristics for the conservation of the African grey parrot in the Korup national park, Cameroon Details PDF · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms ...

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    Bobcokono, Irene Yatabene. Vol 1, No 1 (2001) - Articles Utilisation du papier filtre dans la gestion de programme de lute contre le SIDA au Cameroun Details PDF · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    Lema, VM. Vol 80, No 9 (2003): - Articles Fournier's gangrene complicating vasectomy. Details PDF · Vol 86, No 6 (2009) - Articles Therapeutic misconception and clinical trials in sub-saharan Africa: A review. Abstract PDF · Vol 86, No 11 (2009) - Articles HIV/AIDS and pregnancy-related deaths in Blantyre, Malawi

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    Green, J.M.. Vol 10, No 1 (2001) - Articles Information from Radio Telemetry on movements and exploitation of naturalized Rainbow trout, Oncorhynchus mykiss (Walbaum), in Kenya cold water streams. Details. ISSN: 0002-0036. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

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    Erasmus, GJ. Vol 1, No 1 (2001) - Articles Genetic parameter estimates for growth traits in purebred Gudali and two-breed synthetic Wakwa beef cattle in a tropical environment. Details PDF · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    Odigie, IP. Vol 10, No 4 (2000) - Articles High dose vitamin E administration attenuates hypertensin in 2-Kidney 1 Clip Goldblatt hypertensive rats. Details. ISSN: 0189-2657. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms ...

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    Motabagani, MA. Vol 80, No 9 (2003): - Articles Anomalies of the renal, phrenic and suprarenal arteries: Case Report Details PDF · Vol 81, No 3 (2004): - Articles Morphological study of the uncommon rectus sterni muscle in German cadavers. Abstract PDF. ISSN: 0012-835X. AJOL African Journals Online. HOW TO USE ...

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    Ibeabuchi, NM. Vol 10, No 3 (2000) - Articles Comparison of the effects of Methylsalicylate Cream with cryotherapy on delayed onset muscle soreness. Details · Vol 22, No 2 (2012) - Articles X-ray Pelvimetry And Labour Outcome In Term Pregnancy In A Rural Nigerian Population Abstract. ISSN: 0189-2657. AJOL African ...

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    Warnorff, DK. Vol 13, No 4 (2001) - Articles Development of a scoring system for the diagnosis of tuberculous lymphadenitis. Details PDF. ISSN: 1995-7262. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions ...

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    South African Journal for Research in Sport, Physical Education and Recreation. ... Ahn, Taesoo. Vol 39, No 1 (2017) - Articles Managing sports brands in a global consumer market: country-of-origin fit in cross-border strategic brand alliances

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    A comparative study on different BMI category and physical fitness health related ... and variableness of competitive adolescent soccer relative performance indicators ... The developmental pathways of Malaysian elite youth badminton players

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    Effects of Dance Movement Therapy on Selected Cardiovascular Parameters and ... Physical Activity Level, Nutritional Intake, Functional Status and Quality of Life of Geriatric Individuals in Lagos, South-West, Nigeria: A Cross Sectional Survey

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    The effects of varied intensities of intrasound therapy with indomethacin on the ... Physical Activity Level, Nutritional Intake, Functional Status and Quality of Life of Geriatric Individuals in Lagos, South-West, Nigeria: A Cross Sectional Survey

  10. Impact of flavor and Higgs physics on theories beyond the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Casagrande, Sandro

    2013-02-13

    Quantum effects of physics beyond the Standard Model receive strong indirect constraints from precisely measured collider observables. In the conceptual part of this thesis, we apply the generic relations between particle interactions in perturbatively unitary theories to calculate one-loop amplitudes for flavor physics. We provide template results applicable for any model of this class. We also investigate example models that are partly and such that are not perturbatively unitary: the Littlest Higgs model and Randall-Sundrum models. The latter have a unique coupling structure, which we cover exhaustively. We find strong constraints on the Randall-Sundrum models and numerically compare those from flavor, electroweak precision, and Higgs physics by performing detailed parameter scans. We observe interesting correlations between flavor observables, and we find that constraints from Higgs production and decays are already competitive.

  11. Impact of flavor and Higgs physics on theories beyond the standard model

    International Nuclear Information System (INIS)

    Casagrande, Sandro

    2013-01-01

    Quantum effects of physics beyond the Standard Model receive strong indirect constraints from precisely measured collider observables. In the conceptual part of this thesis, we apply the generic relations between particle interactions in perturbatively unitary theories to calculate one-loop amplitudes for flavor physics. We provide template results applicable for any model of this class. We also investigate example models that are partly and such that are not perturbatively unitary: the Littlest Higgs model and Randall-Sundrum models. The latter have a unique coupling structure, which we cover exhaustively. We find strong constraints on the Randall-Sundrum models and numerically compare those from flavor, electroweak precision, and Higgs physics by performing detailed parameter scans. We observe interesting correlations between flavor observables, and we find that constraints from Higgs production and decays are already competitive.

  12. Validations and improvements of airfoil trailing-edge noise prediction models using detailed experimental data

    DEFF Research Database (Denmark)

    Kamruzzaman, M.; Lutz, Th.; Würz, W.

    2012-01-01

    This paper describes an extensive assessment and a step by step validation of different turbulent boundary-layer trailing-edge noise prediction schemes developed within the European Union funded wind energy project UpWind. To validate prediction models, measurements of turbulent boundary-layer pr...... with measurements in the frequency region higher than 1 kHz, whereas they over-predict the sound pressure level in the low-frequency region. Copyright © 2011 John Wiley & Sons, Ltd.......-layer properties such as two-point turbulent velocity correlations, the spectra of the associated wall pressure fluctuations and the emitted trailing-edge far-field noise were performed in the laminar wind tunnel of the Institute of Aerodynamics and Gas Dynamics, University of Stuttgart. The measurements were...... carried out for a NACA 643-418 airfoil, at Re  =  2.5 ×106, angle of attack of −6° to 6°. Numerical results of different prediction schemes are extensively validated and discussed elaborately. The investigations on the TNO-Blake noise prediction model show that the numerical wall pressure fluctuation...

  13. Detailed analysis of the African green monkey model of Nipah virus disease.

    Directory of Open Access Journals (Sweden)

    Sara C Johnston

    Full Text Available Henipaviruses are implicated in severe and frequently fatal pneumonia and encephalitis in humans. There are no approved vaccines or treatments available for human use, and testing of candidates requires the use of well-characterized animal models that mimic human disease. We performed a comprehensive and statistically-powered evaluation of the African green monkey model to define parameters critical to disease progression and the extent to which they correlate with human disease. African green monkeys were inoculated by the intratracheal route with 2.5 × 10(4 plaque forming units of the Malaysia strain of Nipah virus. Physiological data captured using telemetry implants and assessed in conjunction with clinical pathology were consistent with shock, and histopathology confirmed widespread tissue involvement associated with systemic vasculitis in animals that succumbed to acute disease. In addition, relapse encephalitis was identified in 100% of animals that survived beyond the acute disease phase. Our data suggest that disease progression in the African green monkey is comparable to the variable outcome of Nipah virus infection in humans.

  14. Teaching Einsteinian Physics at Schools: Part 2, Models and Analogies for Quantum Physics

    Science.gov (United States)

    Kaur, Tejinder; Blair, David; Moschilla, John; Zadnik, Marjan

    2017-01-01

    The Einstein-First project approaches the teaching of Einsteinian physics through the use of physical models and analogies. This paper presents an approach to the teaching of quantum physics which begins by emphasising the particle-nature of light through the use of toy projectiles to represent photons. This allows key concepts including the…

  15. Engaging Students In Modeling Instruction for Introductory Physics

    Science.gov (United States)

    Brewe, Eric

    2016-05-01

    Teaching introductory physics is arguably one of the most important things that a physics department does. It is the primary way that students from other science disciplines engage with physics and it is the introduction to physics for majors. Modeling instruction is an active learning strategy for introductory physics built on the premise that science proceeds through the iterative process of model construction, development, deployment, and revision. We describe the role that participating in authentic modeling has in learning and then explore how students engage in this process in the classroom. In this presentation, we provide a theoretical background on models and modeling and describe how these theoretical elements are enacted in the introductory university physics classroom. We provide both quantitative and video data to link the development of a conceptual model to the design of the learning environment and to student outcomes. This work is supported in part by DUE #1140706.

  16. Theoretical spectral properties of PAHs: towards a detailed model of their photophysics in the ISM

    International Nuclear Information System (INIS)

    Malloci, Giuliano; Mulas, Giacomo; Porceddu, Ignazio

    2005-01-01

    In the framework of density functional theory (DFT) we computed the spectral properties of a total of about 20 polycyclic aromatic hydrocarbons (PAHs) in different charge states. From our complete atlas of PAHs, ranging in size from naphthalene (C 10 H 8 ) to dicoronylene (C 48 H 20 ), we present here a sample of results concerning both ground-state and excited-state properties. Our theoretical results are in reasonable agreement with the available experimental data. This makes them particularly precious when the latter are not easily obtainable, as is often the case for the highly reactive radicals and ions of such species. In another paper (Mulas et al., same volume) we show that our theoretical results can be reliably used to model the behaviour of these molecules in astrophysical environments

  17. Mathematical gauge theory with applications to the standard model of particle physics

    CERN Document Server

    Hamilton, Mark J D

    2017-01-01

    The Standard Model is the foundation of modern particle and high energy physics. This book explains the mathematical background behind the Standard Model, translating ideas from physics into a mathematical language and vice versa. The first part of the book covers the mathematical theory of Lie groups and Lie algebras, fibre bundles, connections, curvature and spinors. The second part then gives a detailed exposition of how these concepts are applied in physics, concerning topics such as the Lagrangians of gauge and matter fields, spontaneous symmetry breaking, the Higgs boson and mass generation of gauge bosons and fermions. The book also contains a chapter on advanced and modern topics in particle physics, such as neutrino masses, CP violation and Grand Unification. This carefully written textbook is aimed at graduate students of mathematics and physics. It contains numerous examples and more than 150 exercises, making it suitable for self-study and use alongside lecture courses. Only a basic knowledge of d...

  18. 1D-Var multilayer assimilation of X-band SAR data into a detailed snowpack model

    Science.gov (United States)

    Phan, X. V.; Ferro-Famil, L.; Gay, M.; Durand, Y.; Dumont, M.; Morin, S.; Allain, S.; D'Urso, G.; Girard, A.

    2014-10-01

    The structure and physical properties of a snowpack and their temporal evolution may be simulated using meteorological data and a snow metamorphism model. Such an approach may meet limitations related to potential divergences and accumulated errors, to a limited spatial resolution, to wind or topography-induced local modulations of the physical properties of a snow cover, etc. Exogenous data are then required in order to constrain the simulator and improve its performance over time. Synthetic-aperture radars (SARs) and, in particular, recent sensors provide reflectivity maps of snow-covered environments with high temporal and spatial resolutions. The radiometric properties of a snowpack measured at sufficiently high carrier frequencies are known to be tightly related to some of its main physical parameters, like its depth, snow grain size and density. SAR acquisitions may then be used, together with an electromagnetic backscattering model (EBM) able to simulate the reflectivity of a snowpack from a set of physical descriptors, in order to constrain a physical snowpack model. In this study, we introduce a variational data assimilation scheme coupling TerraSAR-X radiometric data into the snowpack evolution model Crocus. The physical properties of a snowpack, such as snow density and optical diameter of each layer, are simulated by Crocus, fed by the local reanalysis of meteorological data (SAFRAN) at a French Alpine location. These snowpack properties are used as inputs of an EBM based on dense media radiative transfer (DMRT) theory, which simulates the total backscattering coefficient of a dry snow medium at X and higher frequency bands. After evaluating the sensitivity of the EBM to snowpack parameters, a 1D-Var data assimilation scheme is implemented in order to minimize the discrepancies between EBM simulations and observations obtained from TerraSAR-X acquisitions by modifying the physical parameters of the Crocus-simulated snowpack. The algorithm then re

  19. Modeling Organizational Design - Applying A Formalism Model From Theoretical Physics

    Directory of Open Access Journals (Sweden)

    Robert Fabac

    2008-06-01

    Full Text Available Modern organizations are exposed to diverse external environment influences. Currently accepted concepts of organizational design take into account structure, its interaction with strategy, processes, people, etc. Organization design and planning aims to align this key organizational design variables. At the higher conceptual level, however, completely satisfactory formulation for this alignment doesn’t exist. We develop an approach originating from the application of concepts of theoretical physics to social systems. Under this approach, the allocation of organizational resources is analyzed in terms of social entropy, social free energy and social temperature. This allows us to formalize the dynamic relationship between organizational design variables. In this paper we relate this model to Galbraith's Star Model and we also suggest improvements in the procedure of the complex analytical method in organizational design.

  20. Searches for Beyond Standard Model Physics with ATLAS and CMS

    CERN Document Server

    Rompotis, Nikolaos; The ATLAS collaboration

    2017-01-01

    The exploration of the high energy frontier with ATLAS and CMS experiments provides one of the best opportunities to look for physics beyond the Standard Model. In this talk, I review the motivation, the strategy and some recent results related to beyond Standard Model physics from these experiments. The review will cover beyond Standard Model Higgs boson searches, supersymmetry and searches for exotic particles.

  1. Numerical models: Detailing and simulation techniques aimed at comparison with experimental data, support to test result interpretation

    International Nuclear Information System (INIS)

    Lin Chiwen

    2001-01-01

    This part of the presentation discusses the modelling details required and the simulation techniques available for analyses, facilitating the comparison with the experimental data and providing support for interpretation of the test results. It is organised to cover the following topics: analysis inputs; basic modelling requirements for reactor coolant system; method applicable for reactor cooling system; consideration of damping values and integration time steps; typical analytic models used for analysis of reactor pressure vessel and internals; hydrodynamic mass and fluid damping for the internal analysis; impact elements for fuel analysis; and PEI theorem and its applications. The intention of these topics is to identify the key parameters associated with models of analysis and analytical methods. This should provide proper basis for useful comparison with the test results

  2. Structural Acoustic Physics Based Modeling of Curved Composite Shells

    Science.gov (United States)

    2017-09-19

    NUWC-NPT Technical Report 12,236 19 September 2017 Structural Acoustic Physics -Based Modeling of Curved Composite Shells Rachel E. Hesse...SUBTITLE Structural Acoustic Physics -Based Modeling of Curved Composite Shells 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...study was to use physics -based modeling (PBM) to investigate wave propagations through curved shells that are subjected to acoustic excitation. An

  3. A generic framework for individual-based modelling and physical-biological interaction

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Mariani, Patrizio; Payne, Mark R.

    2018-01-01

    The increased availability of high-resolution ocean data globally has enabled more detailed analyses of physical-biological interactions and their consequences to the ecosystem. We present IBMlib, which is a versatile, portable and computationally effective framework for conducting Lagrangian...... scales. The open-source framework features a minimal robust interface to facilitate the coupling between individual-level biological models and oceanographic models, and we provide application examples including forward/backward simulations, habitat connectivity calculations, assessing ocean conditions...

  4. Simulation of biatrial conduction via different pathways during sinus rhythm with a detailed human atrial model

    Institute of Scientific and Technical Information of China (English)

    Dong-dong DENG; Ying-lan GONG; Guo-fa SHOU; Pei-feng JIAO; Heng-gui ZHANG; Xue-song YE; Ling XIA

    2012-01-01

    In order to better understand biatrial conduction,investigate various conduction pathways,and compare the differences between isotropic and anisotropic conductions in human atria,we present a simulation study of biatrial conduction with known/assumed conduction pathways using a recently developed human atrial model.In addition to known pathways:(1) Bachmann's bundle (BB),(2) limbus of fossa ovalis (LFO),and (3) coronary sinus (CS),we also hypothesize that there exist two fast conduction bundles that connect the crista terminalis (CT),LFO,and CS.Our simulation demonstrates that use of these fast conduction bundles results in a conduction pattern consistent with experimental data.The comparison of isotropic and anisotropoic conductions in the BB case showed that the atrial working muscles had small effect on conduction time and conduction speed,although the conductivities assigned in anisotropic conduction were two to four times higher than the isotropic conduction.In conclusion,we suggest that the hypothesized intercaval bundles play a significant role in the biatrial conduction and that myofiber orientation has larger effects on the conduction system than the atrial working muscles.This study presents readers with new insights into human atrial conduction.

  5. Physics-Based Pneumatic Hammer Instability Model, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Florida Turbine Technologies (FTT) proposes to conduct research necessary to develop a physics-based pneumatic hammer instability model for hydrostatic bearings...

  6. Flavor physics and right-handed models

    Energy Technology Data Exchange (ETDEWEB)

    Shafaq, Saba

    2010-08-20

    The Standard Model of particle physics only provides a parametrization of flavor which involves the values of the quark and lepton masses and unitary flavor mixing matrix i.e. CKM (Cabibbo-Kobayashi-Masakawa) matrix for quarks. The precise determination of elements of the CKM matrix is important for the study of the flavor sector of quarks. Here we concentrate on the matrix element vertical stroke V{sub cb} vertical stroke. In particular we consider the effects on the value of vertical stroke V{sub cb} vertical stroke from possible right-handed admixtures along with the usually left-handed weak currents. Left Right Symmetric Model provide a natural basis for right-handed current contributions and has been studied extensively in the literature but has never been discussed including flavor. In the first part of the present work an additional flavor symmetry is included in LRSM which allows a systematic study of flavor effects. The second part deals with the practical extraction of a possible right-handed contribution. Starting from the quark level transition b{yields}c we use heavy quark symmetries to relate the helicities of the quarks to experimentally accessible quantities. To this end we study the decays anti B{yields}D(D{sup *})l anti {nu} which have been extensively explored close to non recoil point. By taking into account SCET (Soft Collinear Effective Theory) formalism it has been extended to a maximum recoil point i.e. {upsilon} . {upsilon}{sup '} >>1. We derive a factorization formula, where the set of form factors is reduced to a single universal form factor {xi}({upsilon} . {upsilon}{sup '}) up to hard-scattering corrections. Symmetry relations on form factors for exclusive anti B {yields} D(D{sup *})l anti {nu} transition has been derived in terms of {xi}({upsilon} . {upsilon}{sup '}). These symmetries are then broken by perturbative effects. The perturbative corrections to symmetry-breaking corrections to first order in the strong

  7. Parameterization of Rocket Dust Storms on Mars in the LMD Martian GCM: Modeling Details and Validation

    Science.gov (United States)

    Wang, Chao; Forget, François; Bertrand, Tanguy; Spiga, Aymeric; Millour, Ehouarn; Navarro, Thomas

    2018-04-01

    The origin of the detached dust layers observed by the Mars Climate Sounder aboard the Mars Reconnaissance Orbiter is still debated. Spiga et al. (2013, https://doi.org/10.1002/jgre.20046) revealed that deep mesoscale convective "rocket dust storms" are likely to play an important role in forming these dust layers. To investigate how the detached dust layers are generated by this mesoscale phenomenon and subsequently evolve at larger scales, a parameterization of rocket dust storms to represent the mesoscale dust convection is designed and included into the Laboratoire de Météorologie Dynamique (LMD) Martian Global Climate Model (GCM). The new parameterization allows dust particles in the GCM to be transported to higher altitudes than in traditional GCMs. Combined with the horizontal transport by large-scale winds, the dust particles spread out and form detached dust layers. During the Martian dusty seasons, the LMD GCM with the new parameterization is able to form detached dust layers. The formation, evolution, and decay of the simulated dust layers are largely in agreement with the Mars Climate Sounder observations. This suggests that mesoscale rocket dust storms are among the key factors to explain the observed detached dust layers on Mars. However, the detached dust layers remain absent in the GCM during the clear seasons, even with the new parameterization. This implies that other relevant atmospheric processes, operating when no dust storms are occurring, are needed to explain the Martian detached dust layers. More observations of local dust storms could improve the ad hoc aspects of this parameterization, such as the trigger and timing of dust injection.

  8. Author Details

    African Journals Online (AJOL)

    Raji, W.O. Vol 8, No 1 (2010) - Articles Rock physics investigation of seismic wave absorption in reservoir rocks. Abstract PDF. ISSN: 1596-6798. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

  9. Author Details

    African Journals Online (AJOL)

    Van Niekerk, RL. Vol 16, No 4 (2010): Supplement - Articles The perceptions and occurrence of sexual harassment among male student athletes with male coaches. Abstract · Vol 16, No 4 (2010): Supplement - Articles Understanding the barriers to and reasons for physical exercise among university students. Abstract.

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    Eniolorunda, OO. Vol 7, No 3 (2011) - Articles Carcass and primal cuts yield evaluation of African antelope (Antilope cervicapra) caught at Ago-Iwoye, Ogun state, Nigeria Abstract · Vol 7, No 3 (2011) - Articles Physical and organoleptic characteristics of chevon as influenced by pos-mortem processing methods. Abstract.

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    Daniel-Ogbonna, C. Vol 48 (2017) - Articles Economic potentials of oil palm products and weed control on sustainable turmeric production and selected soil physical properties in southeastern Nigeria Abstract. ISSN: 0300-368X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

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    African Journals Online (AJOL)

    Ano, A.O.. Vol 48 (2017) - Articles Economic potentials of oil palm products and weed control on sustainable turmeric production and selected soil physical properties in southeastern Nigeria Abstract. ISSN: 0300-368X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

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    Achebe, U. Vol 48 (2017) - Articles Economic potentials of oil palm products and weed control on sustainable turmeric production and selected soil physical properties in southeastern Nigeria Abstract. ISSN: 0300-368X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

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    Korieocha, D.S.. Vol 48 (2017) - Articles Economic potentials of oil palm products and weed control on sustainable turmeric production and selected soil physical properties in southeastern Nigeria Abstract. ISSN: 0300-368X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

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    Njoku, N.R.. Vol 48 (2017) - Articles Economic potentials of oil palm products and weed control on sustainable turmeric production and selected soil physical properties in southeastern Nigeria Abstract. ISSN: 0300-368X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

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    Back translation reliability of TEOSQ in team game, individual game and gender category. Abstract PDF · Vol 9, No ... Relative age effect in physical attributes and motor fitness at different birth-month quartile ... Sensitivity pattern recognition and variableness of competitive adolescent soccer relative performance indicators

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    Abstract PDF · Vol 14, No 4 (1979) - Articles Studies on the littoral seaweed epifauna of St. Croix Island. I. Physical and biological features of the littoral zone. Abstract PDF · Vol 14, No 4 (1979) - Articles Aspects of the biology, ecology and seasonal fluctuations in biochemical conlposition of Donax serra in 'the East Cape

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    Nasiru, A. Vol 31, No 3 (2012) - Articles Assessment of Noise Generated By Operations within the Gunduwawa Quarry in Kano State, Nigeria Abstract PDF · Vol 34, No 2 (2015) - Chemical, Industrial, Materials, Mechanical, Metallurgical, Petroleum & Production Engineering Chemical and Physical Comparative Study of the ...

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    African Journals Online (AJOL)

    Arwui, Cyrus Cyril. Vol 61 (2017) - Articles Planning for nuclear security: Design Basis Threats and physical protection systems. Abstract PDF. ISSN: 1991-3877. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    African Journals Online (AJOL)

    Nutritional, Physical and Culinary Characteristics of Tuberous Roots of Newly Developed Sweetpotato Genotypes in Nigeria Abstract · Vol 43 (2012) - Articles Yield Evaluation and Morphological Variability of Tubers of Intra-Specific Hybrids of Dioscorea Rotundata Abstract · Vol 43 (2012) - Articles Socio-Economic ...

  1. Author Details

    African Journals Online (AJOL)

    Echendu, TNC. Vol 35 (2004) - Articles Control of Mosaic disease of cassava by manipulation of planting date and propagation materials of resistant genotypes. Abstract · Vol 41, No 1 (2010) - Articles Nutritional, Physical and Culinary Characteristics of Tuberous Roots of Newly Developed Sweetpotato Genotypes in Nigeria

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    African Journals Online (AJOL)

    Ukpabi, UJ. Vol 39 (2008) - Articles Preliminary elations of temperate sugar beet accession s for tuber yield and quality 8in the high altitude of Jos plateau, Nigeria Abstract · Vol 41, No 1 (2010) - Articles Nutritional, Physical and Culinary Characteristics of Tuberous Roots of Newly Developed Sweetpotato Genotypes in ...

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    Effects of 16 weeks of aerobic, resistance and combination exercise programmes on smoking. Abstract · Vol 13, No 1 (2007): - Articles Effects of acute stretching on the maximal expression of strength. Abstract · Vol 13, No 2 (2007): - Articles Physical education: A qualitative study of grade 10 learners' perceptions

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    Okae-Anti, D. Vol 38, No 2 (2005): National Agricultural Research System - Articles Respiration rate in some soils as affected by physical and chemical properties. Abstract. ISSN: 0855-0042. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

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    8th All Africa Pre-Games' Scientific Congress - Report and Declaration ... Children\\'s perceptions of physical education and school sports at selected South ... The Effect of Participation in Competitive Sports on School Connectedness of Secondary School Students Abstract. ISSN: 1117-4315. AJOL African Journals Online.

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    African Journal for Physical, Health Education, Recreation and Dance. ... and long jump in 10-15 year old girls from disadvantaged communities in South Africa ... characteristics of stunted and non-stunted black South African boys living in a ...

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    Prevalence and risk factors of arternal hypertension among urban Africans workplace: The obsolete role of body mass index. Abstract · Vol 17, No 1 (2008) - Articles Diets rich in vegetables and physical activity are associated with a decreased risk in pregnancy induced hypertension among rural women from Kimpese, DR ...

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    Abstract · Vol 6, No 1 (2012) - Articles Physical Characteristics of Water Used by Haramaya University and the Effects of Heating and Cooling on the Amount of Extracted Solids Abstract · Vol 8, No 1 (2014) - Articles Comparative Study on Wind Power using Meteorological Data and Wind Turbine Output at Ashogoda Village, ...

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    Scientometric analysis of the Ethiopian Journal of Agricultural Sciences Abstract PDF · Vol 26, No 1 (2015) - Articles Physic nut (Jatropha curcas): miracle plant or a treat in Ethiopia? Abstract PDF · Vol 27, No 1 (2016) - Articles Challenges Associated with Crop Breeding for Adaptation to Drought-Prone Environments

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    Ley, Clemens. Vol 11, No 2 (2012) - Articles A narrative review of research on the effects of physical activity on people living with HIV and opportunities for health promotion in disadvantaged settings. Abstract · Vol 13, No 4 (2014) - Articles Effects of an exercise programme with people living with HIV: research in a ...

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    Pienaar, Anita E. Vol 9, No 1 (2003) - Articles Anthropometric, physical and motor fitness profiles of 10 to 15-year old girls in the north west province of South Africa: implications for sport talent identification. Abstract · Vol 8, No 1 (2002) - Articles Current level of gross motor development of 3-6 year-old children in ...

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    Swanepoel, M. Vol 23, No 1:1 (2017) - Articles A comparative overview of exercise and health related professions: Athletic training, clinical exercise physiology and biokinetics. Abstract · Vol 23, No 1:2 (2017) - Articles Relationship between physical activity, body fatness and cardiorespiratory fitness in South African ...

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    Akande, GR. Vol 29, No 1 (2011) - Articles Thermo-Physical Properties of Farmed African Freshwater Catfish (Clarias gariepinus) Fillet for Process Design and Optimization Abstract. ISSN: 0189-7241. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

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    Steyn, NP. Special Edition. Food and nutrition challenges in Southern Africa. Vol 2 (2017) - Articles Food choices, physical activity levels and other factors associated with weight gain in primary school educators. Abstract PDF. ISSN: 0378-5254. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

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    Madukwe, D.K. Vol 3, No 1 (2008) - Articles Effects of organic manure and cowpea (Vigna unguiculata (l.) Walp) varieties on the chemical properties of the soil and root nodulation. Abstract PDF · Vol 3, No 2 (2008) - Articles Effects of poultry manure and cow dung on the physical and chemical properties of crude oil polluted ...

  16. Standard Model Physics at the LHC

    CERN Document Server

    CERN. Geneva

    1999-01-01

    1. Top Physics : Single top production and top polarization, D. O'Neil. Top mass determination, spin correlations and t-tbar asymmetries, L. Sonnenschein. FCNC-induced production and decays, S. Slabospitsky. MC tools for signals and backgrounds, M. Mangano. Plans for the writing of the final report, Conveners. Top physics: Discussion. 2. Electroweak physics (cont.) : Anomalous triple gauge boson couplings: analysis, strategies, and form factor considerations, M. Dobbs. Sensitivity to anomalous triple gauge boson couplings, W. Thuemmel. Drell-Yan production of W,Z with electroweak corrections, S. Dittmaier. Vector boson self-couplings and effective field theory, J.R. Pelaez. Recent theoretical progress, Z. Kunszt. Electroweak physics: Discussion. Recent theoretical progress in b production, G. Ridolf. Studies on b production, S. Gennai. Comparison of most recent b-production theoretical computations with PYTHIA, A. Kharchilava. Possibilities for b production measurements, P. Vikas. B production: Discussion....

  17. B physics in the standard model

    International Nuclear Information System (INIS)

    Takasugi, Eiichi

    1985-01-01

    Before discussing the beauty physics, the present status of the quark mixing is reviewed. Then the CP violation in the K meson physics is discussed. As for the quark mixing, it is concluded that the theroretical analysis of CP violation involves various uncertainties and it seems difficult to obtain the definite information of the quark mixing. As for the B physics, B 0 - anti B 0 mixing and some hopeful methods to detect the CP violation in the B system are discussed along with the two typical ways to measure it. In summary, it is concluded that the B 0 - anti B 0 mixing should be observed, but some luck is needed to observe the CP violation in the B physics. (Aoki, K.)

  18. Implications of Model Structure and Detail for Utility Planning. Scenario Case Studies using the Resource Planning Model

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Trieu [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Barrows, Clayton [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hale, Elaine [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dyson, Mark [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eurek, Kelly [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-04-23

    We examine how model investment decisions change under different model configurations and assumptions related to renewable capacity credit, the inclusion or exclusion of operating reserves, dispatch period sampling, transmission power flow modeling, renewable spur line costs, and the ability of a planning region to import and export power. For all modeled scenarios, we find that under market conditions where new renewable deployment is predominantly driven by renewable portfolio standards, model representations of wind and solar capacity credit and interactions between balancing areas are most influential in avoiding model investments in excess thermal capacity. We also compare computation time between configurations to evaluate tradeoffs between computational burden and model accuracy. From this analysis, we find that certain advanced dispatch representations (e.g., DC optimal power flow) can have dramatic adverse effects on computation time but can be largely inconsequential to model investment outcomes, at least at the renewable penetration levels modeled. Finally, we find that certain underappreciated aspects of new capacity investment decisions and model representations thereof, such as spur lines for new renewable capacity, can influence model outcomes particularly in the renewable technology and location chosen by the model. Though this analysis is not comprehensive and results are specific to the model region, input assumptions, and optimization-modeling framework employed, the findings are intended to provide a guide for model improvement opportunities.

  19. Background report to the OECD Environmental Outlook to 2030. Overviews, details, and methodology of model-based analysis

    International Nuclear Information System (INIS)

    Bakkes, J.A.; Bagnoli, P.; Chateau, J.; Corfee-Morlot, J.; Kim, Y.G.

    2008-01-01

    This background report provides overviews and details of the model-based analyses for the Outlook. The global analyses have been conducted for 24 regions. They cover: climate change; urban air pollution and related health impacts; nutrient loading to the aquatic environment by agriculture and by trends in sanitation and sewerage; terrestrial biodiversity. A baseline scenario has been developed, as well as three policy packages. Most of the model-based analyses for the Environmental Outlook include a retrospect to 1970 and a look forward up to 2050. This enables an assessment of the cost of policy inaction and of the delaying of such action. This background report compares the impacts of the baseline for the various regions of the world. It also assesses the impact of uncertainties in the modelling for the key messages of the Environmental Outlook

  20. Author Details

    African Journals Online (AJOL)

    Mathematical modeling of rainwater runoff over catchment surface and mass transfer of contaminant incoming to water stream from soil ... Numerical model of rainwater runoff over the catchment surface and transport of contaminant incoming ...

  1. DISCRETE DEFORMATION WAVE DYNAMICS IN SHEAR ZONES: PHYSICAL MODELLING RESULTS

    Directory of Open Access Journals (Sweden)

    S. A. Bornyakov

    2016-01-01

    Full Text Available Observations of earthquake migration along active fault zones [Richter, 1958; Mogi, 1968] and related theoretical concepts [Elsasser, 1969] have laid the foundation for studying the problem of slow deformation waves in the lithosphere. Despite the fact that this problem has been under study for several decades and discussed in numerous publications, convincing evidence for the existence of deformation waves is still lacking. One of the causes is that comprehensive field studies to register such waves by special tools and equipment, which require sufficient organizational and technical resources, have not been conducted yet.The authors attempted at finding a solution to this problem by physical simulation of a major shear zone in an elastic-viscous-plastic model of the lithosphere. The experiment setup is shown in Figure 1 (A. The model material and boundary conditions were specified in accordance with the similarity criteria (described in detail in [Sherman, 1984; Sherman et al., 1991; Bornyakov et al., 2014]. The montmorillonite clay-and-water paste was placed evenly on two stamps of the installation and subject to deformation as the active stamp (1 moved relative to the passive stamp (2 at a constant speed. The upper model surface was covered with fine sand in order to get high-contrast photos. Photos of an emerging shear zone were taken every second by a Basler acA2000-50gm digital camera. Figure 1 (B shows an optical image of a fragment of the shear zone. The photos were processed by the digital image correlation method described in [Sutton et al., 2009]. This method estimates the distribution of components of displacement vectors and strain tensors on the model surface and their evolution over time [Panteleev et al., 2014, 2015].Strain fields and displacements recorded in the optical images of the model surface were estimated in a rectangular box (220.00×72.17 mm shown by a dot-and-dash line in Fig. 1, A. To ensure a sufficient level of

  2. Author Details

    African Journals Online (AJOL)

    Dynamic Modeling of Natural Convection Solar Energy Collectors for Agricultural Driers I: Theory and Complete Run of the Solutions to the Dynamic Model Equations of SSSCA Flat Plate Collector Abstract PDF · Vol 26, No 2 (2007) - Research papers. Dynamic Modeling of Natural Convection Solar Energy Flat Plate ...

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    African Journals Online (AJOL)

    Makhtar, M. Vol 9, No 6S (2017) - Articles A classification framework for drug relapse prediction. Abstract PDF · Vol 9, No 6S (2017) - Articles Selection of classification models from repository of model for water quality dataset. Abstract PDF · Vol 9, No 6S (2017) - Articles Churn classification model for local telecommunication ...

  4. Author Details

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    Oyesanya, MO. Vol 12 (2008) - Articles Duffing oscillator as model for predicting earthquake occurrence I Abstract · Vol 14 (2009) - Articles A mathematical model for predicting earthquake occurrence. Abstract · Vol 14 (2009) - Articles Hopf bifurcations in a fractional reaction–diffusion model for the invasion and development ...

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    African Journals Online (AJOL)

    Modelling of California Bearing Ratio with Unconfined Compressive Strength for Cement Stabilized Laterite Soil Abstract · Vol 30 (2015) - Articles A Mathematical Model for the Comparative Study of the Blast Response of Aluminium and Steel Panels Abstract · Vol 30 (2015) - Articles Modelling Convergence of Finite ...

  6. THE PRODUCTION OF COMPLEX PROFILE DETAILS BY COMBINED METHOD OF LOST-WAX CASTING AND OF CONSUMABLE PATTERN MODELS

    Directory of Open Access Journals (Sweden)

    O. I. Shinsky

    2016-01-01

    Full Text Available The technological process of receiving figurine castings of a heat resisting alloy HN57KTVYuMBL brand developed and tested by authors a combined method of oflost-wax casting (pouring gate system and of consumable expanded polystyrene pattern in shell forms kompleks modify ceramics promotes decrease in crack formation of forms at the expense of correctly picked up temperature and time mode of annealing of a form with model. Besides this method allows to receive figurine castings with minimization of an allowance for machining of details, to increase their geometrical accuracy and to lower a roughness.

  7. Academic detailing.

    Science.gov (United States)

    Shankar, P R; Jha, N; Piryani, R M; Bajracharya, O; Shrestha, R; Thapa, H S

    2010-01-01

    There are a number of sources available to prescribers to stay up to date about medicines. Prescribers in rural areas in developing countries however, may not able to access some of them. Interventions to improve prescribing can be educational, managerial, and regulatory or use a mix of strategies. Detailing by the pharmaceutical industry is widespread. Academic detailing (AD) has been classically seen as a form of continuing medical education in which a trained health professional such as a physician or pharmacist visits physicians in their offices to provide evidence-based information. Face-to-face sessions, preferably on an individual basis, clear educational and behavioural objectives, establishing credibility with respect to objectivity, stimulating physician interaction, use of concise graphic educational materials, highlighting key messages, and when possible, providing positive reinforcement of improved practices in follow-up visits can increase success of AD initiatives. AD is common in developed countries and certain examples have been cited in this review. In developing countries the authors have come across reports of AD in Pakistan, Sudan, Argentina and Uruguay, Bihar state in India, Zambia, Cuba, Indonesia and Mexico. AD had a consistent, small but potentially significant impact on prescribing practices. AD has much less resources at its command compared to the efforts by the industry. Steps have to be taken to formally start AD in Nepal and there may be specific hindering factors similar to those in other developing nations.

  8. Construction and validation of detailed kinetic models for the combustion of gasoline surrogates; Construction et validation de modeles cinetiques detailles pour la combustion de melanges modeles des essences

    Energy Technology Data Exchange (ETDEWEB)

    Touchard, S.

    2005-10-15

    The irreversible reduction of oil resources, the CO{sub 2} emission control and the application of increasingly strict standards of pollutants emission lead the worldwide researchers to work to reduce the pollutants formation and to improve the engine yields, especially by using homogenous charge combustion of lean mixtures. The numerical simulation of fuel blends oxidation is an essential tool to study the influence of fuel formulation and motor conditions on auto-ignition and on pollutants emissions. The automatic generation helps to obtain detailed kinetic models, especially at low temperature, where the number of reactions quickly exceeds thousand. The main purpose of this study is the generation and the validation of detailed kinetic models for the oxidation of gasoline blends using the EXGAS software. This work has implied an improvement of computation rules for thermodynamic and kinetic data, those were validated by numerical simulation using CHEMKIN II softwares. A large part of this work has concerned the understanding of the low temperature oxidation chemistry of the C5 and larger alkenes. Low and high temperature mechanisms were proposed and validated for 1 pentene, 1-hexene, the binary mixtures containing 1 hexene/iso octane, 1 hexene/toluene, iso octane/toluene and the ternary mixture of 1 hexene/toluene/iso octane. Simulations were also done for propene, 1-butene and iso-octane with former models including the modifications proposed in this PhD work. If the generated models allowed us to simulate with a good agreement the auto-ignition delays of the studied molecules and blends, some uncertainties still remains for some reaction paths leading to the formation of cyclic products in the case of alkenes oxidation at low temperature. It would be also interesting to carry on this work for combustion models of gasoline blends at low temperature. (author)

  9. Particle modeling of plasmas computational plasma physics

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1991-01-01

    Recently, through the development of supercomputers, a powerful new method for exploring plasmas has emerged; it is computer modeling of plasmas. Such modeling can duplicate many of the complex processes that go on in a plasma and allow scientists to understand what the important processes are. It helps scientists gain an intuition about this complex state of matter. It allows scientists and engineers to explore new ideas on how to use plasma before building costly experiments; it allows them to determine if they are on the right track. It can duplicate the operation of devices and thus reduce the need to build complex and expensive devices for research and development. This is an exciting new endeavor that is in its infancy, but which can play an important role in the scientific and technological competitiveness of the US. There are a wide range of plasma models that are in use. There are particle models, fluid models, hybrid particle fluid models. These can come in many forms, such as explicit models, implicit models, reduced dimensional models, electrostatic models, magnetostatic models, electromagnetic models, and almost an endless variety of other models. Here the author will only discuss particle models. He will give a few examples of the use of such models; these will be taken from work done by the Plasma Modeling Group at UCLA because he is most familiar with work. However, it only gives a small view of the wide range of work being done around the US, or for that matter around the world

  10. PWR surveillance based on correspondence between empirical models and physical

    International Nuclear Information System (INIS)

    Zwingelstein, G.; Upadhyaya, B.R.; Kerlin, T.W.

    1976-01-01

    An on line surveillance method based on the correspondence between empirical models and physicals models is proposed for pressurized water reactors. Two types of empirical models are considered as well as the mathematical models defining the correspondence between the physical and empirical parameters. The efficiency of this method is illustrated for the surveillance of the Doppler coefficient for Oconee I (an 886 MWe PWR) [fr

  11. Physical Modelling of Geotechnical Structures in Ports and Offshore

    Directory of Open Access Journals (Sweden)

    Bałachowski Lech

    2017-04-01

    Full Text Available The physical modelling of subsoil behaviour and soil-structure interaction is essential for the proper design of offshore structures and port infrastructure. A brief introduction to such modelling of geoengineering problems is presented and some methods and experimental devices are described. The relationships between modelling scales are given. Some examples of penetration testing results in centrifuge and calibration chamber are presented. Prospects for physical modelling in geotechnics are also described.

  12. Detailed qualitative dynamic knowledge representation using a BioNetGen model of TLR-4 signaling and preconditioning.

    Science.gov (United States)

    An, Gary C; Faeder, James R

    2009-01-01

    Intracellular signaling/synthetic pathways are being increasingly extensively characterized. However, while these pathways can be displayed in static diagrams, in reality they exist with a degree of dynamic complexity that is responsible for heterogeneous cellular behavior. Multiple parallel pathways exist and interact concurrently, limiting the ability to integrate the various identified mechanisms into a cohesive whole. Computational methods have been suggested as a means of concatenating this knowledge to aid in the understanding of overall system dynamics. Since the eventual goal of biomedical research is the identification and development of therapeutic modalities, computational representation must have sufficient detail to facilitate this 'engineering' process. Adding to the challenge, this type of representation must occur in a perpetual state of incomplete knowledge. We present a modeling approach to address this challenge that is both detailed and qualitative. This approach is termed 'dynamic knowledge representation,' and is intended to be an integrated component of the iterative cycle of scientific discovery. BioNetGen (BNG), a software platform for modeling intracellular signaling pathways, was used to model the toll-like receptor 4 (TLR-4) signal transduction cascade. The informational basis of the model was a series of reference papers on modulation of (TLR-4) signaling, and some specific primary research papers to aid in the characterization of specific mechanistic steps in the pathway. This model was detailed with respect to the components of the pathway represented, but qualitative with respect to the specific reaction coefficients utilized to execute the reactions. Responsiveness to simulated lipopolysaccharide (LPS) administration was measured by tumor necrosis factor (TNF) production. Simulation runs included evaluation of initial dose-dependent response to LPS administration at 10, 100, 1000 and 10,000, and a subsequent examination of

  13. Energy Return on Investment (EROI) for Forty Global Oilfields Using a Detailed Engineering-Based Model of Oil Production

    Science.gov (United States)

    Brandt, Adam R.; Sun, Yuchi; Bharadwaj, Sharad; Livingston, David; Tan, Eugene; Gordon, Deborah

    2015-01-01

    Studies of the energy return on investment (EROI) for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER) ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER) ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs), nor does it include other indirect energy uses such as labor or services. PMID:26695068

  14. Energy Return on Investment (EROI for Forty Global Oilfields Using a Detailed Engineering-Based Model of Oil Production.

    Directory of Open Access Journals (Sweden)

    Adam R Brandt

    Full Text Available Studies of the energy return on investment (EROI for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs, nor does it include other indirect energy uses such as labor or services.

  15. Author Details

    African Journals Online (AJOL)

    Gichuhi, AW. Vol 16, No 1 (2014) - Articles Estimation of change point in binomial random variables. Abstract · Vol 16, No 1 (2014) - Articles Classification rates: non‐parametric verses parametric models using binary data. Abstract · Vol 14, No 1 (2012) - Articles Parametric modeling of probability of bank loan default in ...

  16. Author Details

    African Journals Online (AJOL)

    Otieno, RO. Vol 16, No 1 (2014) - Articles Classification rates: non‐parametric verses parametric models using binary data. Abstract · Vol 14, No 1 (2012) - Articles Parametric modeling of probability of bank loan default in Kenya Abstract. ISSN: 1561-7645. AJOL African Journals Online. HOW TO USE AJOL.

  17. Author Details

    African Journals Online (AJOL)

    ... incomplete market: application to a South African retirement fund. Abstract · Vol 11 (2011) - Articles The capital-asset pricing model: the case of South Africa Abstract · Vol 13 (2013) - Articles The capital-asset pricing model reconsidered: tests in real terms on a South African market portfolio comprising equities and bonds

  18. Author Details

    African Journals Online (AJOL)

    Adnan, R. Vol 9, No 4S (2017): Special Issue - Articles Comparison between MPC and PID control for compact hydro distillation process. Abstract PDF · Vol 9, No 4S (2017): Special Issue - Articles Modeling and controller design on ARX model of Electro-Hydrolic actuator. Abstract PDF · Vol 9, No 4S (2017): Special Issue - ...

  19. Author Details

    African Journals Online (AJOL)

    Model Predictive Control Fundamentals Abstract PDF · Vol 34, No 4 (2015) - Computer, Telecommunications, Software, Electrical & Electronics Engineering Fuzzy Control Technique Applied to Modified Mathematical Model for Malaria Control Abstract PDF · Vol 35, No 4 (2016) - Computer, Telecommunications, Software, ...

  20. Author Details

    African Journals Online (AJOL)

    An Analysis of Yip's Global Strategy Model, Using Coca-Cola Strategic Leadership Model Abstract · Vol 4, No 1-2 (2010) - Articles Factors influencing quality of leadership in public higher institutions of learning in Ghana Abstract · Vol 5, No 1-2 (2011) - Articles Institutional Evaluation Program (IEP) as a Governance Tool in ...

  1. Concepts and models in particle physics

    International Nuclear Information System (INIS)

    Paty, M.

    1977-01-01

    The knowledge of Elementary Particle Physics is characterized by an object and a purpose which are both highly theoretical. This assessment is shown and analysed by some examples taken in recent achievements in the field. It is also tried to attempt an enonciation of some criteria of the reality for concepts and objects in this matter [fr

  2. Extracting physics from the lattice higgs model

    International Nuclear Information System (INIS)

    Neuberger, H.

    1988-05-01

    The relevance and usefulness of lattice /phi/ 4 for particle physics is discussed from older and newer points of view. The talk will start with a review of the main ideas and suggestions in my work in the past with Dashen and will proceed to present newer developments both on the conceptual and the practical level. 12 refs

  3. An Amotivation Model in Physical Education

    Science.gov (United States)

    Shen, Bo; Wingert, Robert K.; Li, Weidong; Sun, Haichun; Rukavina, Paul Bernard

    2010-01-01

    Amotivation refers to a state in which individuals cannot perceive a relationship between their behavior and that behavior's subsequent outcome. With the belief that considering amotivation as a multidimensional construct could reflect the complexity of motivational deficits in physical education, we developed this study to validate an amotivation…

  4. Aespoe modelling task force - experiences of the site specific flow and transport modelling (in detailed and site scale)

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden); Stroem, A.; Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co. , Stockholm (Sweden)

    1998-09-01

    The Aespoe Task Force on modelling of groundwater flow and transport of solutes was initiated in 1992. The Task Force shall be a forum for the organisations supporting the Aespoe Hard Rock Laboratory Project to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Much emphasis is put on building of confidence in the approaches and methods in use for modelling of groundwater flow and nuclide migration in order to demonstrate their use for performance and safety assessment. The modelling work within the Task Force is linked to the experiments performed at the Aespoe Laboratory. As the first Modelling Task, a large scale pumping and tracer experiment called LPT2 was chosen. This was the final part of the characterisation work for the Aespoe site before the construction of the laboratory in 1990. The construction of the Aespoe HRL access tunnel caused an even larger hydraulic disturbance on a much larger scale than that caused by the LPT2 pumping test. This was regarded as an interesting test case for the conceptual and numerical models of the Aespoe site developed during Task No 1, and was chosen as the third Modelling Task. The aim of Task 3 can be seen from two different perspectives. The Aespoe HRL project saw it as a test of their ability to define a conceptual and structural model of the site that can be utilised by independent modelling groups and be transformed to a predictive groundwater flow model. The modelling groups saw it as a means of understanding groundwater flow in a large fractured rock volume and of testing their computational tools. A general conclusion is that Task 3 has served these purposes well. Non-sorbing tracers tests, made as a part of the TRUE-experiments were chosen as the next predictive modelling task. A preliminary comparison between model predictions made by the Aespoe Task Force and the experimental results, shows that most modelling teams predicted breakthrough from

  5. Compilation of a global N{sub 2}O emission inventory for tropical rainforest soils using a detailed biogeochemical model

    Energy Technology Data Exchange (ETDEWEB)

    Werner, C.

    2007-09-15

    Nitrous oxide (N{sub 2}O) is a potent trace gas contributing to approximately 6% to the observed anthropogenic global warming. Soils have been identified to be the major source of atmospheric N{sub 2}O and tropical rainforest soils are thought to account for the largest part. Furthermore, various studies have shown that the magnitude of N{sub 2}O emissions from tropical rainforest soil is highly variable on spatial and temporal scales. Detailed, process-based models coupled to Geographic Information Systems (GIS) are considered promising tools for the calculation of N{sub 2}O emission inventories. This methodology explicitly accounts for the governing microbial processes as well as the environmental controls. Moreover, mechanistic biogeochemical models operating in daily time-steps (e.g. ForestDNDC-tropica) have been shown to capture the observed intra- and inter-annual variations of N{sub 2}O emissions. However, detailed N{sub 2}O emission datasets are required for model calibration and testing, but are currently few in numbers. In this study an automated measurement system was used to derive detailed datasets of N{sub 2}O, methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) soil-atmosphere exchange and important environmental parameters from tropical rainforest soils in Kenya and Southwest China. Distinct differences were identified in the magnitude of the C and N soil-atmosphere exchange at the investigated sites and forest types. However, common features such as N{sub 2}O pulse emissions after dry season or the pronounced soil moisture dependency of N{sub 2}O emissions were observed at both sites. The derived datasets are unique for these tropical regions as so far no information about the source strength of these regions was available and, for the first time, the N{sub 2}O, CH{sub 4} and CO{sub 2} soil-atmosphere exchange was recorded in sub-daily resolution. The datasets were utilized in conjunction with available high-resolution datasets from Australian

  6. Hydrogeological modelling of the eastern region of Areco river locally detailed on Atucha I and II nuclear power plants area

    International Nuclear Information System (INIS)

    Grattone, Natalia I.; Fuentes, Nestor O.

    2009-01-01

    Water flow behaviour of Pampeano aquifer was modeled using Visual Mod-flow software Package 2.8.1 with the assumption of a free aquifer, within the region of the Areco river and extending to the rivers of 'Canada Honda' and 'de la Cruz'. Steady state regime was simulated and grid refinement allows obtaining locally detailed calculation in the area of Atucha I and II Nuclear power plants, in order to compute unsteady situations as the consequence of water flow variations from and to the aquifer, enabling the model to study the movement of possible contaminant particles in the hydrogeologic system. In this work the effects of rivers action, the recharge conditions and the flow lines are analyzed, taking always into account the range of reliability of obtained results, considering the incidence of uncertainties introduced by data input system, the estimates and interpolation of parameters used. (author)

  7. Detailed modeling of hydrodynamics mass transfer and chemical reactions in a bubble column using a discrete bubble model

    NARCIS (Netherlands)

    Darmana, D.; Deen, N.G.; Kuipers, J.A.M.

    2005-01-01

    A 3D discrete bubble model is adopted to investigate complex behavior involving hydrodynamics, mass transfer and chemical reactions in a gas¿liquid bubble column reactor. In this model a continuum description is adopted for the liquid phase and additionally each individual bubble is tracked in a

  8. Detailed modeling of hydrodynamics mass transfer and chemical reactions in a bubble column using a discrete bubble model

    NARCIS (Netherlands)

    Darmana, D.; Deen, N.G.; Kuipers, J.A.M.

    2005-01-01

    A 3D discrete bubble model is adopted to investigate complex behavior involving hydrodynamics, mass transfer and chemical reactions in a gas–liquid bubble column reactor. In this model a continuum description is adopted for the liquid phase and additionally each individual bubble is tracked in a

  9. Modeling Long-Term Fluvial Incision : Shall we Care for the Details of Short-Term Fluvial Dynamics?

    Science.gov (United States)

    Lague, D.; Davy, P.

    2008-12-01

    Fluvial incision laws used in numerical models of coupled climate, erosion and tectonics systems are mainly based on the family of stream power laws for which the rate of local erosion E is a power function of the topographic slope S and the local mean discharge Q : E = K Qm Sn. The exponents m and n are generally taken as (0.35, 0.7) or (0.5, 1), and K is chosen such that the predicted topographic elevation given the prevailing rates of precipitation and tectonics stay within realistic values. The resulting topographies are reasonably realistic, and the coupled system dynamics behaves somehow as expected : more precipitation induces increased erosion and localization of the deformation. Yet, if we now focus on smaller scale fluvial dynamics (the reach scale), recent advances have suggested that discharge variability, channel width dynamics or sediment flux effects may play a significant role in controlling incision rates. These are not factored in the simple stream power law model. In this work, we study how these short- term details propagate into long-term incision dynamics within the framework of surface/tectonics coupled numerical models. To upscale the short term dynamics to geological timescales, we use a numerical model of a trapezoidal river in which vertical and lateral incision processes are computed from fluid shear stress at a daily timescale, sediment transport and protection effects are factored in, as well as a variable discharge. We show that the stream power law model might still be a valid model but that as soon as realistic effects are included such as a threshold for sediment transport, variable discharge and dynamic width the resulting exponents m and n can be as high as 2 and 4. This high non-linearity has a profound consequence on the sensitivity of fluvial relief to incision rate. We also show that additional complexity does not systematically translates into more non-linear behaviour. For instance, considering only a dynamical width

  10. Author Details

    African Journals Online (AJOL)

    Synthesis of organoamine-silica hybrids using cashew nut shell liquid components as templates for the catalysis of a model Henry reaction ... Inhibitor of Aloe Secundiflora Extract in Corrosion Control of Carbon Steel in Soft Water Media

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    African Journals Online (AJOL)

    AHP) Model Abstract · Vol 18 (2011) - Articles Adaptive Kernel In The Bootstrap Boosting Algorithm In KDE Abstract · Vol 18 (2011) - Articles An Empirical Comparison of HTML, PHP, COLDFUSION, PERL, ASP.net, Javascript, VBScript, Pyton and ...

  12. Hybrid computer modelling in plasma physics

    International Nuclear Information System (INIS)

    Hromadka, J; Ibehej, T; Hrach, R

    2016-01-01

    Our contribution is devoted to development of hybrid modelling techniques. We investigate sheath structures in the vicinity of solids immersed in low temperature argon plasma of different pressures by means of particle and fluid computer models. We discuss the differences in results obtained by these methods and try to propose a way to improve the results of fluid models in the low pressure area. There is a possibility to employ Chapman-Enskog method to find appropriate closure relations of fluid equations in a case when particle distribution function is not Maxwellian. We try to follow this way to enhance fluid model and to use it in hybrid plasma model further. (paper)

  13. Physical models of biological information and adaptation.

    Science.gov (United States)

    Stuart, C I

    1985-04-07

    The bio-informational equivalence asserts that biological processes reduce to processes of information transfer. In this paper, that equivalence is treated as a metaphor with deeply anthropomorphic content of a sort that resists constitutive-analytical definition, including formulation within mathematical theories of information. It is argued that continuance of the metaphor, as a quasi-theoretical perspective in biology, must entail a methodological dislocation between biological and physical science. It is proposed that a general class of functions, drawn from classical physics, can serve to eliminate the anthropomorphism. Further considerations indicate that the concept of biological adaptation is central to the general applicability of the informational idea in biology; a non-anthropomorphic treatment of adaptive phenomena is suggested in terms of variational principles.

  14. Physical models of semiconductor quantum devices

    CERN Document Server

    Fu, Ying

    2013-01-01

    The science and technology relating to nanostructures continues to receive significant attention for its applications to various fields including microelectronics, nanophotonics, and biotechnology. This book describes the basic quantum mechanical principles underlining this fast developing field. From the fundamental principles of quantum mechanics to nanomaterial properties, from device physics to research and development of new systems, this title is aimed at undergraduates, graduates, postgraduates, and researchers.

  15. Model of future officers' availability to the management physical training

    Directory of Open Access Journals (Sweden)

    Olkhovy O.M.

    2012-03-01

    Full Text Available A purpose of work is creation of model of readiness of graduating student to implementation of official questions of guidance, organization and leadthrough of physical preparation in the process of military-professional activity. An analysis is conducted more than 40 sources and questionnaire questioning of a 21 expert. For introduction of model to the system of physical preparation of students the list of its basic constituents is certain: theoretical methodical readiness; functionally-physical readiness; organizationally-administrative readiness. It is certain that readiness of future officers to military-professional activity foresees determination of level of forming of motive capabilities, development of general physical qualities.

  16. Comparison Study on Low Energy Physics Model of GEANT4

    International Nuclear Information System (INIS)

    Park, So Hyun; Jung, Won Gyun; Suh, Tae Suk

    2010-01-01

    The Geant4 simulation toolkit provides improved or renewed physics model according to the version. The latest Geant4.9.3 which has been recoded by developers applies inserted Livermore data and renewed physics model to the low energy electromagnetic physics model. And also, Geant4.9.3 improved the physics factors by modified code. In this study, the stopping power and CSDA(Continuously Slowing Down Approximation) range data of electron or particles were acquired in various material and then, these data were compared with NIST(National Institute of Standards and Technology) data. Through comparison between data of Geant4 simulation and NIST, the improvement of physics model on low energy electromagnetic of Geant4.9.3 was evaluated by comparing the Geant4.9.2

  17. A Detailed Model of Electroenzymatic Glutamate Biosensors To Aid in Sensor Optimization and in Applications in Vivo.

    Science.gov (United States)

    Clay, Mackenzie; Monbouquette, Harold G

    2018-02-21

    Simulations conducted with a detailed model of glutamate biosensor performance describe the observed sensor performance well, illustrate the limits of sensor performance, and suggest a path toward sensor optimization. Glutamate is the most important excitatory neurotransmitter in the brain, and electroenzymatic sensors have emerged as a useful tool for the monitoring of glutamate signaling in vivo. However, the utility of these sensors currently is limited by their sensitivity and response time. A mathematical model of a typical glutamate biosensor consisting of a Pt electrode coated with a permselective polymer film and a top layer of cross-linked glutamate oxidase has been constructed in terms of differential material balances on glutamate, H 2 O 2 , and O 2 in one spatial dimension. Simulations suggest that reducing thicknesses of the permselective polymer and enzyme layers can increase sensitivity ∼6-fold and reduce response time ∼7-fold, and thereby improve resolution of transient glutamate signals. At currently employed enzyme layer thicknesses, both intrinsic enzyme kinetics and enzyme deactivation likely are masked by mass transfer. However, O 2 -dependence studies show essentially no reduction in signal at the lowest anticipated O 2 concentrations for expected glutamate concentrations in the brain and that O 2 transport limitations in vitro are anticipated only at glutamate concentrations in the mM range. Finally, the limitations of current biosensors in monitoring glutamate transients is simulated and used to illustrate the need for optimized biosensors to report glutamate signaling accurately on a subsecond time scale. This work demonstrates how a detailed model can be used to guide optimization of electroenzymatic sensors similar to that for glutamate and to ensure appropriate interpretation of data gathered using such biosensors.

  18. Physics constrained nonlinear regression models for time series

    International Nuclear Information System (INIS)

    Majda, Andrew J; Harlim, John

    2013-01-01

    A central issue in contemporary science is the development of data driven statistical nonlinear dynamical models for time series of partial observations of nature or a complex physical model. It has been established recently that ad hoc quadratic multi-level regression (MLR) models can have finite-time blow up of statistical solutions and/or pathological behaviour of their invariant measure. Here a new class of physics constrained multi-level quadratic regression models are introduced, analysed and applied to build reduced stochastic models from data of nonlinear systems. These models have the advantages of incorporating memory effects in time as well as the nonlinear noise from energy conserving nonlinear interactions. The mathematical guidelines for the performance and behaviour of these physics constrained MLR models as well as filtering algorithms for their implementation are developed here. Data driven applications of these new multi-level nonlinear regression models are developed for test models involving a nonlinear oscillator with memory effects and the difficult test case of the truncated Burgers–Hopf model. These new physics constrained quadratic MLR models are proposed here as process models for Bayesian estimation through Markov chain Monte Carlo algorithms of low frequency behaviour in complex physical data. (paper)

  19. Evaluation of the 235U prompt fission neutron spectrum including a detailed analysis of experimental data and improved model information

    Science.gov (United States)

    Neudecker, Denise; Talou, Patrick; Kahler, Albert C.; White, Morgan C.; Kawano, Toshihiko

    2017-09-01

    We present an evaluation of the 235U prompt fission neutron spectrum (PFNS) induced by thermal to 20-MeV neutrons. Experimental data and associated covariances were analyzed in detail. The incident energy dependence of the PFNS was modeled with an extended Los Alamos model combined with the Hauser-Feshbach and the exciton models. These models describe prompt fission, pre-fission compound nucleus and pre-equilibrium neutron emissions. The evaluated PFNS agree well with the experimental data included in this evaluation, preliminary data of the LANL and LLNL Chi-Nu measurement and recent evaluations by Capote et al. and Rising et al. However, they are softer than the ENDF/B-VII.1 (VII.1) and JENDL-4.0 PFNS for incident neutron energies up to 2 MeV. Simulated effective multiplication factors keff of the Godiva and Flattop-25 critical assemblies are further from the measured keff if the current data are used within VII.1 compared to using only VII.1 data. However, if this work is used with ENDF/B-VIII.0β2 data, simulated values of keff agree well with the measured ones.

  20. The role of a detailed aqueous phase source release model in the LANL area G performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E.L.; Shuman, R.; Hollis, D.K. [Los Alamos National Lab., NM (United States)] [and others

    1995-12-31

    A preliminary draft of the Performance Assessment for the Los Alamos National Laboratory (LANL) low-level radioactive waste disposal facility at Area G is currently being completed as required by Department of Energy orders. A detailed review of the inventory data base records and the existing models for source release led to the development of a new modeling capability to describe the liquid phase transport from the waste package volumes. Nuclide quantities are sorted down to four waste package release categories for modeling: rapid release, soil, concrete/sludge, and corrosion. Geochemistry for the waste packages was evaluated in terms of the equilibrium coefficients, Kds, and elemental solubility limits, Csl, interpolated from the literature. Percolation calculations for the base case closure cover show a highly skewed distribution with an average of 4 mm/yr percolation from the disposal unit bottom. The waste release model is based on a compartment representation of the package efflux, and depends on package size, percolation rate or Darcy flux, retardation coefficient, and moisture content.

  1. Physical and mathematical models of communication systems

    International Nuclear Information System (INIS)

    Verkhovskaya, E.P.; Yavorskij, V.V.

    2006-01-01

    The theoretical parties connecting resources of communication system with characteristics of channels are received. The model of such systems from positions quasi-classical thermodynamics is considered. (author)

  2. Numerical modeling for flame dynamics and combustion processes in a two-sectional porous burner with a detailed chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Jun; Kim, Yong Mo [Hanyang University, Seoul (Korea, Republic of)

    2014-11-15

    A two-dimensional model with the detailed chemistry and variable transport properties has been applied to numerically investigate the combustion processes and flame dynamics in the bilayer porous burner. To account for the velocity transition and diffusion influenced by solid matrix, porosity terms are included in the governing equations. Heat transfer coefficient is calculated by Nusselt number to reflect the effect of gas velocity, pore diameter, and material properties. The detailed chemistry is based on GRI 2.11. Numerical results indicate that the present approach is capable of the essential features of the premixed combustion in the porous media in terms of the precise flame structure, pollutant formation, and stabilization characteristics. In this bilayer porous burner, the heat transferred from the downstream flame zone is conducted to the upstream flame region through the solid matrix. This heat transfer process through the solid matrix substantially influences the flame structure and stabilization characteristics in the porous media. The predicted results are compared with experimental data in terms of temperature for gaseous mixture and solid matrix, CO and NO emission level. Based on numerical results, a precise comparison has been made for the freely propagating premixed flames and the premixed flames with a porous media for various inlet velocities.

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    African Journals Online (AJOL)

    Jordaan, JC. Vol 17, No 3 (2013) - Articles Impact of interest rate changes on South African GDP and households: a combined macroeconomic and social accounting matrix modelling approach. Abstract PDF. ISSN: 1998-8125. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

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    African Journals Online (AJOL)

    Mahapatra, S. Vol 2, No 5 (2010) - Articles Modeling, simulation and parametric optimization of wire EDM process using response surface methodology coupled with grey-Taguchi technique. Abstract PDF. ISSN: 2141-2839. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

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    African Journals Online (AJOL)

    Chado, UD. Vol 21, No 4 (2017) - Articles A Mathematical Model for the Dynamics of Zika Virus via Homotopy Perturbation Method Abstract PDF. ISSN: 1119-8362. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    Boon, Marinus Axel. Vol 5, No 2 (2016) - Articles Unmanned Aerial Vehicle (UAV) photogrammetry produces accurate high-resolution orthophotos, point clouds and surface models for mapping wetlands. Abstract PDF. ISSN: 2225-8531. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

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    Ekaka-a, EN. Vol 16, No 2 (2012) - Articles Sensitivity Analysis of a Physiochemical Interaction Model Undergoing Changes in the Initial Condition and Duration of Experiment Time Abstract PDF · Vol 16, No 3 (2012) - Articles The Role of Numerical Methods in the Sensitivity Analysis of a Density Parameter in a Passivation ...

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    African Journals Online (AJOL)

    A Mathematical Model for Predicting Output in an Oilfield in the Niger Delta Area of Nigeria Abstract PDF · Vol 35, No 2 (2016) - Chemical, Industrial, Materials, Mechanical, Metallurgical, Petroleum & Production Engineering ANALYSIS OF FLOW IN A CONCENTRIC ANNULUS USING FINITE ELEMENT METHOD

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    African Journals Online (AJOL)

    Goshwe, NY. Vol 12 (2013) - Articles Prediction of Path loss Estimate for a Frequency Modulation (FM) Station Using Basic Transmission Loss Model Abstract PDF. ISSN: 1596-292X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

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    African Journals Online (AJOL)

    Igwue, GA. Vol 12 (2013) - Articles Prediction of Path loss Estimate for a Frequency Modulation (FM) Station Using Basic Transmission Loss Model Abstract PDF. ISSN: 1596-292X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

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    African Journals Online (AJOL)

    Mbajiorgu, C.C.. Vol 36, No 4 (2017) - Research papers. Prediction of the impacts of climate changes on the stream flow of Ajali River Watershed using SWAT model. Abstract PDF. ISSN: 2467-8821. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

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    African Journals Online (AJOL)

    Fasina, E.P. Vol 22, No 1 (2015) - Articles Evaluation of a flexible column-based access control security model for medical-based information. Abstract. ISSN: 2006-5523. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    African Journals Online (AJOL)

    Okpala, OO. Vol 5, No 2 (2009) - Articles Predictive ability of boiler production models. Abstract. ISSN: 0794-4721. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL · News. OTHER ...

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    African Journals Online (AJOL)

    Adamu, SS. Vol 33, No 3 (2014) - Research papers. Neural Network Based Model of an Industrial Oil-Fired Boiler System Abstract PDF. ISSN: 2467-8821. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of ...

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    African Journals Online (AJOL)

    Muthukrishnan, S. M.. Vol 9, No 4S (2017): Special Issue - Articles Systematic mapping review on student's performance analysis using big data predictive model. Abstract PDF. ISSN: 1112-9867. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

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    African Journals Online (AJOL)

    Kayode, O.J.. Vol 10, No 1 (2008) - Articles A binary logistic regression model for the adoption of electronic banking in Akure, Ondo State Abstract PDF. ISSN: 0794-4896. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

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    African Journals Online (AJOL)

    Shima, N. Vol 9, No 1S (2017): Special Issue - Articles Examining the factors affecting willingness to use electronic banking: the integration of TAM and TPB models with electronic service quality (case study: Eghtesad Novin Bank) Abstract PDF. ISSN: 1112-9867. AJOL African Journals Online. HOW TO USE AJOL.

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    Adegoke, B.O.A. Vol 19, No 3 (2009) - Articles Back School: The Development of A Nigerian Urban Model Abstract. ISSN: 0189-2657. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

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    African Journals Online (AJOL)

    Mohamed, M.A.. Vol 9, No 6S (2017) - Articles Churn classification model for local telecommunication company based on rough set theory. Abstract PDF. ISSN: 1112-9867. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms ...

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    African Journals Online (AJOL)

    Rothmann, S. Vol 25, No 2 (2005) - Articles An adapted model of burnout for educators in South Africa Abstract PDF · Vol 33, No 2 (2013) - Articles Callings, work role fit, psychological meaningfulness and work engagement among teachers in Zambia Abstract PDF. ISSN: 2076-3433. AJOL African Journals Online. HOW TO ...