WorldWideScience

Sample records for model systems investigations

  1. Investigation of Interference Models for RFID Systems

    Directory of Open Access Journals (Sweden)

    Linchao Zhang

    2016-02-01

    Full Text Available The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

  2. Modeling of enterprise information systems implementation: a preliminary investigation

    Science.gov (United States)

    Yusuf, Yahaya Y.; Abthorpe, M. S.; Gunasekaran, Angappa; Al-Dabass, D.; Onuh, Spencer

    2001-10-01

    The business enterprise has never been in greater need of Agility and the current trend will continue unabated well into the future. It is now recognized that information system is both the foundation and a necessary condition for increased responsiveness. A successful implementation of Enterprise Resource Planning (ERP) can help a company to move towards delivering on its competitive objectives as it enables suppliers to reach out to customers beyond the borders of traditional market defined by geography. The cost of implementation, even when it is successful, could be significant. Bearing in mind the potential strategic benefits, it is important that the implementation project is managed effectively. To this end a project cost model against which to benchmark ongoing project expenditure versus activities completed has been proposed in this paper.

  3. An investigation of factors affecting elementary school students' BMI values based on the system dynamics modeling.

    Science.gov (United States)

    Lan, Tian-Syung; Chen, Kai-Ling; Chen, Pin-Chang; Ku, Chao-Tai; Chiu, Pei-Hsuan; Wang, Meng-Hsiang

    2014-01-01

    This study used system dynamics method to investigate the factors affecting elementary school students' BMI values. The construction of the dynamic model is divided into the qualitative causal loop and the quantitative system dynamics modeling. According to the system dynamics modeling, this study consisted of research on the four dimensions: student's personal life style, diet-relevant parenting behaviors, advocacy and implementation of school nutrition education, and students' peer interaction. The results of this study showed that students with more adequate health concepts usually have better eating behaviors and consequently have less chance of becoming obese. In addition, this study also verified that educational attainment and socioeconomic status of parents have a positive correlation with students' amounts of physical activity, and nutrition education has a prominent influence on changing students' high-calorie diets.

  4. Oceanic sill-overflow systems: Investigations and simulation with the Poseidon ocean general circulation model

    Science.gov (United States)

    Anderson, Whit G.

    Marginal seas transport dense water into the oceanic system by deep gravity currents through sill-overflow systems. This dense water is essential in establishing background characteristics and the density driven component of the meridional overturing of the ocean. This thesis investigates the controlling dynamics and several modeling issues related to oceanic deep gravity currents. The objectives and questions of this study center on the development of a climate scale model that adequately simulates sill-overflow deep gravity currents. These questions include the sensitivity of the model to resolution and various turbulence parameterizations when modeling these systems. A hybrid generalized vertical coordinate model is adapted to address these questions. This study uses theoretical model domains based on the Dynamics of Mixing and Entrainment group (DOME). Current, climate scale models typically have horizontal resolutions ranging from 1/2 to 1 degree resolution. The bulk of the vertical resolution in layered models is commonly placed in density or pressure space centered around the equatorial upper ocean, well away from the regions containing the deep gravity currents investigated in this study. Models solutions from this study show large dependence on both horizontal and vertical resolution. When horizontal resolution is decreased from 5 to 20 km, entrainment of ambient water into the gravity current decreases by approximately a factor of 3. The deep gravity currents in the lower (20 km) resolution experiments are deeper, denser and have larger along-slope velocities than the higher resolution experiments (5 km). This difference is explained by the homogenization of the gravity current in lower resolution simulations. The 5 km simulations show higher magnitudes and spatial variability of momentum. This homogenization results in underestimation of the applied bottom stress in the model. With a lower bottom stress, the current does not have sufficient shearing to

  5. Modelling small groundwater systems - the role of targeted field investigations and observational data in reducing model uncertainty

    Science.gov (United States)

    Abesser, Corinna; Hughes, Andrew; Boon, David

    2017-04-01

    Coastal dunes are delicate systems that are under threat from a variety of human and natural influences. Groundwater modelling can provide a better understanding of how these systems operate and can be a useful tool towards the effective management of a coastal dune system, e.g. through predicting impacts from climatic change, sea level rise and land use management. Because of their small size, typically 10 - 100 km2, models representing small dune aquifer systems are more sensitive to uncertainties in input data, model geometry and model parameterisation as well as to the availability of observational data. This study describes the development of a groundwater flow model for a small (8 km2) spit dune system, Braunton Burrows, on the Southwest coast of England, UK. The system has been extensively studied and its hydrology is thought to be well understood. However, model development revealed a high degree of uncertainty relating to model structure (definition of model boundary conditions) and parameterisation (e.g., transmissivity distributions within the model domain). An iterative approach was employed, integrating (1) sensitivity analyses, (2) targeted field investigations and (3) Monte Carlo simulations within a cycle of repeated interrogation of the model outputs, observed data and conceptual understanding. Assessment of "soft information" and targeted field investigations were an important part of this iterative modelling process. For example, a passive seismic survey (TROMINO®) provided valuable new data for the characterisation of concealed bedrock topography and thickness of superficial deposits. The data confirmed a generally inclined underlying wave cut rock shelf platform (as suggested by literature sources), revealed a buried valley, and led to a more detailed delineation of transmissivity zones within the model domain. Constructing models with increasingly more complex spatial distributions of transmissivity, resulted in considerable improvements in

  6. Investigation of the Nonlinear Model of the Cellular Population System Development

    Directory of Open Access Journals (Sweden)

    M. S. Vinogradova

    2014-01-01

    Full Text Available An isolated population system is considered which consists of two types of human stem cells: normal cells and cells with chromosomal anomalies (abnormal. In the paper the nonlinear dynamic model which describes dynamics of cell populations developing in vitro is elaborated. The model allows to investigate the processes of the formation of the abnormal cells population from the abnormal cells population of normal cells as well as joint development of these populations. The model takes into account the limited resources.An important feature of the developed model is the use of biological characteristics of processes in the cell population system, such as the proportion of cells, divided over a specified time, the proportion of cells whish are not divided, and which are "lost" and which are passed in the population of abnormal cells from the normal population. This approach allows a more detailed analysis of the impact of various "primary" parameters on the evolution of the population system.Under cultivation of cell populations in vitro a struggle for resources primarily affects the processes of the cell reproduction. This is reflected in the existence of the dividing cells frequency dependence of the total population of normal and abnormal cells. For the account of such dependencies different non-linear functions are typically used. However, the use of such non-linear relationships leads to the difficulties in finding confidence intervals for the estimates of the model parameters at subsequent stages of research. At the same time, the problem of the system parameters estimating and finding of the corresponding confidence intervals for estimates can be solved easy in case when the nonlinear system is linear with respect to the unknown parameters. In the paper it is achieved due to the piecewise linear approximation of nonlinear dependencies.An important feature of the model is a different view of the right part of the differential equations system

  7. Investigation of the Effects of a Nursing Information System by Using the Technology Acceptance Model.

    Science.gov (United States)

    Hsu, Hung-Hsiou; Wu, Ya-Hui

    2017-06-01

    The purposes of this study are to investigate the effectiveness of implementing a nursing information system and to discuss several issues affecting its successful deployment from the perspectives of nurses, the major users of the system. The methodology was based on the theory of the technology acceptance model. This study adopted a cross-sectional study method to survey and collect data. In total, 167 questionnaires were distributed to subjects. Approximately 94.6%, or 158 valid questionnaires, were collected. The data were analyzed using SPSS and PLS software.The data analysis indicated that the factors that most significantly influenced the willingness of nurses to use the nursing information system were their degrees of satisfaction with the system and their perceptions of its usefulness. A nursing information system that can provide functions that are useful and convenient and that facilitate the avoidance of tedious repetitive writing and improve the quality of provided care can encourage nurse satisfaction with the system and thus stimulate their interest in using it for their work. The ease of use of the system can also affect the willingness of nurses to use it.

  8. Investigation of flow-induced vibration for energy harvesting using a model soap-film system

    Science.gov (United States)

    Yang, Wenchao; Stremler, Mark; Virginia Tech Team

    2017-11-01

    One way to extract energy from geophysical flows is to take advantage of flow-induced vibration (FIV) caused by vortices being shed from a bluff body. Wake-induced vibration of the downstream cylinder in a tandem pair is a promising design for a FIV energy harvesting system, especially suitable for low Reynolds number flows. For this design, the upstream cylinder is fixed in place, while the downstream cylinder is free to oscillate like a pendulum that is driven by interactions with the flow, including the wake of the upstream cylinder. We use a flowing soap film system, with behavior that resembles two-dimensional hydrodynamics, to experimentally investigate the wake interaction between a stationary upstream circular disk and a free downstream circular disk, which acts as a swinging pendulum. The wake flow generates thickness variations in the thin soap film, allowing direct observation of wake patterns through visualization of interference fringes. With the ability to tie together the wake structure and the object motion, we investigate the relationship between energy generation and flow structure in the simplified model energy harvesting system for Re =150. The research results find the optimal efficiency of the energy harvesting system by a parametric study.

  9. Investigating dye performance and crosstalk in fluorescence enabled bioimaging using a model system

    DEFF Research Database (Denmark)

    Arppe, Riikka; R. Carro-Temboury, Miguel; Hempel, Casper

    2017-01-01

    studies and between research groups very difficult. Therefore, we suggest a model system to benchmark instrumentation, methods and staining procedures. The system we introduce is based on doped zeolites in stained polyvinyl alcohol (PVA) films: a highly accessible model system which has the properties......-talk of fluorophores on the detected fluorescence signal. The described model system comprises of lanthanide (III) ion doped Linde Type A zeolites dispersed in a PVA film stained with fluorophores. We tested: F18, MitoTracker Red and ATTO647N. This model system allowed comparing performance of the fluorophores...

  10. A biomechanical model of the human defecatory system to investigate mechanisms of continence.

    Science.gov (United States)

    Stokes, William E; Jayne, David G; Alazmani, Ali; Culmer, Peter R

    2018-02-01

    This article presents a method to fabricate, measure and control a physical simulation of the human defecatory system to investigate individual and combined effects of anorectal angle and sphincter pressure on continence. To illustrate the capabilities and clinical relevance of the work, the influence of a passive-assistive artificial anal sphincter (FENIX TM ) is evaluated. A model rectum and associated soft tissues, based on geometry from an anonymised computed tomography dataset, was fabricated from silicone and showed behavioural realism to the biological system and ex vivo tissue. Simulated stool matter with similar rheological properties to human faeces was developed. Instrumentation and control hardware were used to regulate injection of simulated stool into the system, automate balloon catheter movement through the anal canal, define the anorectal angle and monitor stool flow rate, intra-rectal pressure, anal canal pressure and puborectalis force. Studies were conducted to examine the response of anorectal angles at 80°, 90° and 100° with simulated stool. Tests were then repeated with the inclusion of a FENIX device. Stool leakage was reduced as the anorectal angle became more acute. Conversely, intra-rectal pressure increased. Overall inclusion of the FENIX reduced faecal leakage, while combined effects of the FENIX and an acute anorectal angle showed the greatest resistance to faecal leakage. These data demonstrate that the anorectal angle and sphincter pressure are fundamental in maintaining continence. Furthermore, it demonstrates that use of the FENIX can increase resistance to faecal leakage and reduce anorectal angles required to maintain continence. Physical simulation of the defecatory system is an insightful tool to better understand, in a quantitative manner, the effects of the anorectal angle and sphincter pressure on continence. This work is valuable in helping improve our understanding of the physical behaviour of the continence mechanism

  11. Novel perfused compression bioreactor system as an in vitro model to investigate fracture healing

    Directory of Open Access Journals (Sweden)

    Waldemar eHoffmann

    2015-02-01

    Full Text Available Secondary bone fracture healing is a physiological process that leads to functional tissue regeneration via endochondral bone formation. In vivo studies have demonstrated that early mobilization and the application of mechanical loads enhances the process of fracture healing. However, the influence of specific mechanical stimuli and particular effects during specific phases of fracture healing remain to be elucidated. In this work, we have developed and provided proof-of-concept of an in vitro human organotypic model of physiological loading of a cartilage callus, based on a novel perfused compression bioreactor system (PCB. We then used the fracture callus model to investigate the regulatory role of dynamic mechanical loading. Our findings provide a proof-of-principle that dynamic mechanical loading applied by the PCB can enhance the maturation process of mesenchymal stromal cells towards late hypertrophic chondrocytes and the mineralization of the deposited extracellular matrix. The PCB provides a promising tool to study fracture healing and for the in vitro assessment of alternative fracture treatments based on engineered tissue grafts or pharmaceutical compounds, allowing for the reduction of animal experiments.

  12. Personal Investigations Processing System

    Data.gov (United States)

    US Agency for International Development — PIPS is a system that maintains the Security/Suitability Investigations Index (SII) for OPM. It contains over 11 million background investigation records of Federal...

  13. Investigating dye performance and crosstalk in fluorescence enabled bioimaging using a model system.

    Directory of Open Access Journals (Sweden)

    Riikka Arppe

    Full Text Available Detailed imaging of biological structures, often smaller than the diffraction limit, is possible in fluorescence microscopy due to the molecular size and photophysical properties of fluorescent probes. Advances in hardware and multiple providers of high-end bioimaging makes comparing images between studies and between research groups very difficult. Therefore, we suggest a model system to benchmark instrumentation, methods and staining procedures. The system we introduce is based on doped zeolites in stained polyvinyl alcohol (PVA films: a highly accessible model system which has the properties needed to act as a benchmark in bioimaging experiments. Rather than comparing molecular probes and imaging methods in complicated biological systems, we demonstrate that the model system can emulate this complexity and can be used to probe the effect of concentration, brightness, and cross-talk of fluorophores on the detected fluorescence signal. The described model system comprises of lanthanide (III ion doped Linde Type A zeolites dispersed in a PVA film stained with fluorophores. We tested: F18, MitoTracker Red and ATTO647N. This model system allowed comparing performance of the fluorophores in experimental conditions. Importantly, we here report considerable cross-talk of the dyes when exchanging excitation and emission settings. Additionally, bleaching was quantified. The proposed model makes it possible to test and benchmark staining procedures before these dyes are applied to more complex biological systems.

  14. Investigations of the Climate System Response to Climate Engineering in a Hierarchy of Models

    Science.gov (United States)

    McCusker, Kelly E.

    Global warming due to anthropogenic emissions of greenhouse gases is causing negative impacts on diverse ecological and human systems around the globe, and these impacts are projected to worsen as climate continues to warm. In the absence of meaningful greenhouse gas emissions reductions, new strategies have been proposed to engineer the climate, with the aim of preventing further warming and avoiding associated climate impacts. We investigate one such strategy here, falling under the umbrella of `solar radiation management', in which sulfate aerosols are injected into the stratosphere. We use a global climate model with a coupled mixed-layer depth ocean and with a fully-coupled ocean general circulation model to simulate the stabilization of climate by balancing increasing carbon dioxide with increasing stratospheric sulfate concentrations. We evaluate whether or not severe climate impacts, such as melting Arctic sea ice, tropical crop failure, or destabilization of the West Antarctic ice sheet, could be avoided. We find that while tropical climate emergencies might be avoided by use of stratospheric aerosol injections, avoiding polar emergencies cannot be guaranteed due to large residual climate changes in those regions, which are in part due to residual atmospheric circulation anomalies. We also find that the inclusion of a fully-coupled ocean is important for determining the regional climate response because of its dynamical feedbacks. The efficacy of stratospheric sulfate aerosol injections, and solar radiation management more generally, depends on its ability to be maintained indefinitely, without interruption from a variety of possible sources, such as technological failure, a breakdown in global cooperation, lack of funding, or negative unintended consequences. We next consider the scenario in which stratospheric sulfate injections are abruptly terminated after a multi- decadal period of implementation while greenhouse gas emissions have continued unabated

  15. Thermodynamic modelling and in-situ neutron diffraction investigation of the (Nd + Mg + Zn) system

    International Nuclear Information System (INIS)

    Zhu, Zhijun; Gharghouri, Michael A.; Pelton, Arthur D.

    2016-01-01

    Highlights: • All phase diagram and thermodynamic data critically assessed for the (Nd + Mg + Zn) system. • All phases described by optimised thermodynamic models. • In-situ neutron diffraction performed to identify phases and transition temperatures. • Assessments of other (RE + Mg + Zn) systems have been carried out simultaneously. • The final product is a thermodynamic database for multicomponent (Mg + RE + Zn) systems. - Abstract: All available phase diagram data for the (Nd + Mg + Zn) system were critically assessed. In-situ neutron diffraction (ND) experiments were performed on selected samples to identify phases and transition temperatures. A critical thermodynamic evaluation and optimization of the (Nd + Mg + Zn) system was carried out and model parameters for the thermodynamic properties of all phases were obtained. The phase transformation behaviour of selected samples was well resolved from the ND experiments and experimental values were used to refine the thermodynamic model parameters.

  16. Thermodynamic modelling and in-situ neutron diffraction investigation of the (Ce + Mg + Zn) system

    International Nuclear Information System (INIS)

    Zhu, Zhijun; Gharghouri, Michael A.; Medraj, Mamoun; Lee, Soo Yeol; Pelton, Arthur D.

    2016-01-01

    Highlights: • All phase diagram and thermodynamic data critically assessed for the (Ce + Mg + Zn) system. • All phases described by optimized thermodynamic models. • In-situ neutron diffraction performed to identify phases and transition temperatures. • Assessments of other (RE + Mg + Zn) systems have been carried out simultaneously. • The final product is a thermodynamic database for multicomponent (Mg + RE + Zn) systems. - Abstract: All available phase diagram data for the (Ce + Mg + Zn) system were critically assessed. In-situ neutron diffraction (ND) experiments were performed on selected samples to identify phases and transition temperatures. A critical thermodynamic evaluation and optimization of the (Ce + Mg + Zn) system were carried out and model parameters for the thermodynamic properties of all phases were obtained. The phase transformation behaviour of selected samples was well resolved from the ND experiments and experimental data were used to refine the thermodynamic model parameters.

  17. Zebrafish: an exciting model for investigating the spatio-temporal pattern of enteric nervous system development.

    LENUS (Irish Health Repository)

    Doodnath, Reshma

    2012-02-01

    AIM: Recently, the zebrafish (Danio rerio) has been shown to be an excellent model for human paediatric research. Advantages over other models include its small size, externally visually accessible development and ease of experimental manipulation. The enteric nervous system (ENS) consists of neurons and enteric glia. Glial cells permit cell bodies and processes of neurons to be arranged and maintained in a proper spatial arrangement, and are essential in the maintenance of basic physiological functions of neurons. Glial fibrillary acidic protein (GFAP) is expressed in astrocytes, but also expressed outside of the central nervous system. The aim of this study was to investigate the spatio-temporal pattern of GFAP expression in developing zebrafish ENS from 24 h post-fertilization (hpf), using transgenic fish that express green fluorescent protein (GFP). METHODS: Zebrafish embryos were collected from transgenic GFP Tg(GFAP:GFP)(mi2001) adult zebrafish from 24 to 120 hpf, fixed and processed for whole mount immunohistochemistry. Antibodies to Phox2b were used to identify enteric neurons. Specimens were mounted on slides and imaging was performed using a fluorescent laser confocal microscope. RESULTS: GFAP:GFP labelling outside the spinal cord was identified in embryos from 48 hpf. The patterning was intracellular and consisted of elongated profiles that appeared to migrate away from the spinal cord into the periphery. At 72 and 96 hpf, GFAP:GFP was expressed dorsally and ventrally to the intestinal tract. At 120 hpf, GFAP:GFP was expressed throughout the intestinal wall, and clusters of enteric neurons were identified using Phox2b immunofluorescence along the pathway of GFAP:GFP positive processes, indicative of a migratory pathway of ENS precursors from the spinal cord into the intestine. CONCLUSION: The pattern of migration of GFAP:GFP expressing cells outside the spinal cord suggests an organized, early developing migratory pathway to the ENS. This shows for the

  18. Bacteria as a new model system for aging studies: investigations using light microscopy.

    Science.gov (United States)

    Ackermann, Martin

    2008-04-01

    Aging-the decline in an individual's condition over time-is at the center of an active research field in medicine and biology. Some very basic questions have, however, remained unresolved, the most fundamental being: do all organisms age? Or are there organisms that would continue to live forever if not killed by external forces? For a long time it was believed that aging only affected organisms such as animals, plants, and fungi. Bacteria, in contrast, were assumed to be potentially immortal and until recently this assertion remained untested. We used phase-contrast microscopy (on an Olympus BX61) to follow individual bacterial cells over many divisions to prove that some bacteria show a distinction between an aging mother cell and a rejuvenated daughter, and that these bacteria thus age. This indicates that aging is a more fundamental property of organisms than was previously assumed. Bacteria can now be used as very simple model system for investigating why and how organisms age.

  19. Investigation and Modelling of Thermal Conditions in Low Flow SDHW Systems

    DEFF Research Database (Denmark)

    Shah, Louise Jivan

    1999-01-01

    . Based on this analysis, two Nusselt-Rayleigh heat transfer correlations were developed - one for the convective heat transfer in the mantle and one for the convective heat transfer in the inner tank. The correlations were used for developing a simulation program for low flow SDHW systems - MANTLSIM...... detailed numerical models· The simulation program MANTLSIM, which was developed in the study may be used as a tool for system design and analysis Keywords:Domestic solar heating, low flow, Computational Fluid Dynamics, Particle Image Velocimetry, dimensional heat transfer analysis, system modelling...

  20. Investigations of a rabbit (Oryctolagus cuniculus model of systemic lupus erythematosus (SLE, BAFF and its receptors.

    Directory of Open Access Journals (Sweden)

    Jiahui Yang

    2009-12-01

    Full Text Available B-cell activation factor belonging to the tumor necrosis factor family (BAFF is a major contributor to survival of B lymphocytes during development and maturation. A relationship between circulating BAFF levels and disease activity has been reported in patients with the autoimmune disease Systemic Lupus Erythematosus (SLE. Clinical trials targeting BAFF or its receptors are currently in progress. In order to further characterize a rabbit (Oryctolagus cuniculus model of SLE, we investigated the expression of BAFF and its receptors in non-inbred, pedigreed rabbits derived from breeding and selection based on autoantibody responses. We immunized rabbits related to previous groups that developed autoantibodies and inflammatory responses after immunizations with peptides synthesized on multiple antigen-branched polylysine backbones. Blood and sera collected before immunization and after boosts were used for health monitoring, analyses of serum autoantibody responses by ELISA and immunofluorescence. Peripheral blood mononuclear cells (PBMC were studied by flow cytometry and were the source of mRNA for quantitative PCR analyses. We hypothesized that BAFF mRNA expression and serum BAFF levels measured indirectly through BAFF receptor binding might increase in autoantibody-producing rabbits. Immunized rabbits developed elevated levels of leucocyte populations, anti-nuclear, anti-dsDNA and other autoantibodies. BR3 mRNA levels in total PBMC decreased and BAFF levels remained low and unchanged in most immunized rabbits. By flow cytometry, percentages of BAFF positive cells decreased. Percentages of transmembrane activator and CAML interactor (TACI decreased in most rabbits from all the immunized groups. The rabbit is an important model for human autoimmune and infectious diseases, and a high quality draft rabbit genome assembly was recently completed. Human disease models developed in non-inbred pedigreed animals are better able to reflect the complexities

  1. A coupled petrological-geodynamical model to investigate the evolution of crustal magmatic systems

    Science.gov (United States)

    Kaus, B. J. P.; Rummel, L.; White, R. W.

    2017-12-01

    The evolution of crustal magmatic systems can be analyzed from different physical and chemical perspectives. Most previous work focus either on the petrological side (considering thermal effects and ignoring mechanics), or on the mechanical evolution (assuming a fixed melt chemistry). Here, we consider both by combining a 2D finite element code, MVEP2, with a thermodynamic modelling approach (Perple_X). Density, melt fraction and the chemical composition of the liquid and solid phase are computed for different starting rock compositions and the evolving chemistry is tracked on markers via 10 main oxides (SiO2-TiO2-Al2O3-Cr2O3-MgO-FeO-CaO-Na2O-K2O-H2O). As soon as the local chemistry changes due to melt extraction, new phase diagrams are computed based on the residual solid chemistry for the deflated magma chamber or on the liquid chemistry for newly generated magma filled fractures. To investigate the chemical evolution in magma chambers and magma filled fractures, we inject mafic sills periodically at varying depth levels into the continental crust. The initial sill injections are focused in either one or two main zones in the crust and may interact with each other. The formation of magma filled fractures from this partially molten zone is tracked with a semi analytical dike initiation algorithm that forms new dikes as a function of the local stress field above the partially molten region and subsequently depletes and compacts the magma source region. Dike generation is thus affected by the background strain rate, amount and depth of melt accumulations as well as parameters that control the plastic and viscous behaviour of the crust (e.g. cohesion, viscous creep flow low etc.). Results show that magma filled fractures triggered by sill injections preferentially form under extensional conditions, particularly within the middle crust (in ca. 25 km depth). Magma chambers in the lower continental crust, on the other hand, are stable over a longer period of time due a

  2. Computational Investigation of a Boundary-Layer Ingestion Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan

    2016-01-01

    This thesis will examine potential propulsive and aerodynamic benefits of integrating a boundary-layer ingestion (BLI) propulsion system with a typical commercial aircraft using the Common Research Model geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment will be used to generate engine conditions for CFD analysis. Improvements to the BLI geometry will be made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.3% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from boundary-layer ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  3. Computational Investigation of a Boundary-Layer Ingesting Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan T.; Elmiligui, Alaa; Geiselhart, Karl A.; Campbell, Richard L.; Maughmer, Mark D.; Schmitz, Sven

    2016-01-01

    The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into a typical commercial aircraft using the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for CFD analysis. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2 deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.4% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from Boundary-Layer Ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  4. A systems-based mathematical modelling framework for investigating the effect of drugs on solid tumours

    Directory of Open Access Journals (Sweden)

    Liu Cong

    2011-12-01

    Full Text Available Abstract Background Elucidating the effects of drugs on solid tumours is a highly challenging multi-level problem, since this involves many complexities associated with transport and cellular response, which in turn is characterized by highly non-linear chemical signal transduction. Appropriate systems frameworks are needed to seriously address the sources of these complexities, especially from the cellular side. Results We develop a skeletal modelling framework incorporating interstitial drug transport, intracellular signal processing and cell population descriptions. The descriptions aim to appropriately capture the nature of information flow. The model is deliberately formulated to start with simple intracellular descriptions so that additional features can be incorporated in a modular fashion. Two kinds of intracellular signalling modules which describe the drug effect were considered, one a monostable switch and the other a bistable switch. Analysis of our model revealed how different drug stimuli can lead to cell killing in the tumour. Interestingly both modules considered exhibited similar trends. The effects of important parameters were also studied. Conclusions We have created a predictive systems platform integrating drug transport and cellular response which can be systematically augmented to include additional layers of cellular complexity. Our results indicate that intracellular signalling models which are qualitatively different can give rise to similar behaviour to simple (and typical stimuli, and that validating intracellular descriptions must be performed with care by considering a variety of drug stimuli.

  5. The LARsen Ice Shelf System, Antarctica, LARISSA a Model for Antarctic Integrated System Science (AISS) Investigations using Marine Platforms

    Science.gov (United States)

    Domack, E. W.; Huber, B. A.; Vernet, M.; Leventer, A.; Scambos, T. A.; Mosley-Thompson, E. S.; Smith, C. R.; de Batist, M. A.; Yoon, H.; Larissa

    2010-12-01

    The LARISSA program is the first interdisciplinary project funded in the AISS program of the NSF Office of Polar Programs and was officially launched in the closing days of the IPY. This program brings together investigators, students, and media to address the rapid and fundamental changes taking place in the region of the Larsen Ice Shelf and surrounding areas. Scientific foci include: glaciologic and oceanographic interactions, the response of pelagic and benthic ecosystems to ice shelf decay, sedimentary record of ice shelf break disintegration, the geologic evolution of ice shelf systems over the last 100,000 years, paleoclimate/environmental records from marine sediment and ice cores, and the crustal response to ice mass loss at decade to millennial time scales. The first major field season took place this past austral summer aboard the NB Palmer (cruise NBP10-01) which deployed with a multi-layered logistical infrastructure that included: two Bell 220 aircraft, a multifunctional deep water ROV, video guided sediment corer, jumbo piston core, and an array of oceanographic and biological sensors and instruments. In tandem with this ship based operation Twin Otter aircraft supported an ice core team upon the crest of the Bruce Plateau with logistic support provided by the BAS at Rothera Station. Although unusually heavy sea ice prevented much of the original work from being completed in the Larsen Embayment the interdisciplinary approach proved useful. Further the logistical model of ship based aircraft to support interdisciplinary work proved viable, again despite an unusually severe summer meterologic pattern across the northern Antarctic Peninsula. As the program moves forward other vessels will come into play and the model can be applied to interdisciplinary objectives in other regions of Antarctica which are remote and lack land based infrastructure to support coastal field programs in glaciology, geology, or meteorology. This work could then be completed

  6. Modeling Acequia Irrigation Systems Using System Dynamics: Model Development, Evaluation, and Sensitivity Analyses to Investigate Effects of Socio-Economic and Biophysical Feedbacks

    Directory of Open Access Journals (Sweden)

    Benjamin L. Turner

    2016-10-01

    Full Text Available Agriculture-based irrigation communities of northern New Mexico have survived for centuries despite the arid environment in which they reside. These irrigation communities are threatened by regional population growth, urbanization, a changing demographic profile, economic development, climate change, and other factors. Within this context, we investigated the extent to which community resource management practices centering on shared resources (e.g., water for agricultural in the floodplains and grazing resources in the uplands and mutualism (i.e., shared responsibility of local residents to maintaining traditional irrigation policies and upholding cultural and spiritual observances embedded within the community structure influence acequia function. We used a system dynamics modeling approach as an interdisciplinary platform to integrate these systems, specifically the relationship between community structure and resource management. In this paper we describe the background and context of acequia communities in northern New Mexico and the challenges they face. We formulate a Dynamic Hypothesis capturing the endogenous feedbacks driving acequia community vitality. Development of the model centered on major stock-and-flow components, including linkages for hydrology, ecology, community, and economics. Calibration metrics were used for model evaluation, including statistical correlation of observed and predicted values and Theil inequality statistics. Results indicated that the model reproduced trends exhibited by the observed system. Sensitivity analyses of socio-cultural processes identified absentee decisions, cumulative income effect on time in agriculture, and land use preference due to time allocation, community demographic effect, effect of employment on participation, and farm size effect as key determinants of system behavior and response. Sensitivity analyses of biophysical parameters revealed that several key parameters (e.g., acres per

  7. Zebrafish as a Model System for Investigating the Compensatory Regulation of Ionic Balance during Metabolic Acidosis

    Directory of Open Access Journals (Sweden)

    Lletta Lewis

    2018-04-01

    Full Text Available Zebrafish (Danio rerio have become an important model for integrative physiological research. Zebrafish inhabit a hypo-osmotic environment; to maintain ionic and acid-base homeostasis, they must actively take up ions and secrete acid to the water. The gills in the adult and the skin at larval stage are the primary sites of ionic regulation in zebrafish. The uptake of ions in zebrafish is mediated by specific ion transporting cells termed ionocytes. Similarly, in mammals, ion reabsorption and acid excretion occur in specific cell types in the terminal region of the renal tubules (distal convoluted tubule and collecting duct. Previous studies have suggested that functional regulation of several ion transporters/channels in the zebrafish ionocytes resembles that in the mammalian renal cells. Additionally, several mechanisms involved in regulating the epithelial ion transport during metabolic acidosis are found to be similar between zebrafish and mammals. In this article, we systemically review the similarities and differences in ionic regulation between zebrafish and mammals during metabolic acidosis. We summarize the available information on the regulation of epithelial ion transporters during acidosis, with a focus on epithelial Na+, Cl− and Ca2+ transporters in zebrafish ionocytes and mammalian renal cells. We also discuss the neuroendocrine responses to acid exposure, and their potential role in ionic compensation. Finally, we identify several knowledge gaps that would benefit from further study.

  8. An Investigation on the Dynamics of High-Speed Systems Using Nonlinear Analytical Floating Ring Bearing Models

    Directory of Open Access Journals (Sweden)

    Athanasios Chasalevris

    2016-01-01

    Full Text Available The scope of this paper is to investigate the dynamics of a rotor-bearing system of high-speed under recently developed analytical bearing models. The development of a theory that can yield the dynamic response of a high-speed system without short/long bearing approximation and without time-consuming numerical methods for the finite-length bearing model is the outcome of this work. The rotor system is introduced as a rigid body so that the dynamics of the system are influenced only from the nonlinear bearing forces which are introduced with closed form expressions. The outcome is a system of nonlinear equations and its solution produces the dynamic response of the high-speed system using exact analytical solution for the bearing forces. The transient dynamic response of the system is evaluated through the wide range of rotating speed and under different bearing solutions including short bearing approximation, presenting the subsynchronous components that are developed when instabilities occur. Time-frequency analysis of the resulting response time-series is presented and the outcome is compared with that obtained from numerical solution of the bearing lubrication and with the short bearing approximation model.

  9. An Agent-Based Modeling Approach to Investigate Emergent Patterns in Ecological Systems

    NARCIS (Netherlands)

    Ellers, Jacintha; Hoogendoorn, Mark; Wendt, David

    2010-01-01

    Due to its suitability, agent-based modeling is more and more often being applied in the domain of Ecology. The development of an agent-based model for the Ecological domain is however very difficult. Usually, many parameters need to be set to appropriate values and such values are not always

  10. Model Intercomparison Study to Investigate a Dense Contaminant Plume in a Complex Hydrogeologic System

    International Nuclear Information System (INIS)

    Williams, Mark D.; Cole, Charles R.; Foley, Michael G.; Zinina, Galina A.; Zinin, Alexander I.; Vasil'Kova, Nelly A.; Samsonova, Lilia M.

    2001-01-01

    A joint Russian and U.S. model intercomparison study was undertaken for developing more realistic contaminant transport models of the Mayak Site, Southern Urals. The test problems were developed by the Russian Team based on their experience modeling contaminant migration near Lake Karachai. The intercomparison problems were designed to address lake and contaminant plume interactions, as well as river interactions and plume density effects. Different numerical codes were used. Overall there is good agreement between the results of both models. Features shown by both models include (1) the sinking of the plume below the lake, (2) the raising of the water table in the fresh water adjacent to the lake in response to the increased pressure from the dense plume, and (3) the formation of a second sinking plume in an area where evapotranspiration exceeded infiltration, thus increasing the solute concentrations above the source (i.e., lake) values

  11. Investigation Into The Model Of The Vehicle System For Speed Support

    Directory of Open Access Journals (Sweden)

    Jurij Grigorovič

    2013-12-01

    Full Text Available The paper presents a rectilinear motion of a car modelled applyingsoftware package “Matlab/Simulink“ where two vehicles aremoving simultaneously one after the other. The parameters ofeach vehicle have been identified separately assessing a driver,road and environment.

  12. Investigation of heat induced reactions between lipid oxidation products and amino acids in lipid rich model systems and hazelnuts.

    Science.gov (United States)

    Karademir, Yeşim; Göncüoğlu, Neslihan; Gökmen, Vural

    2013-07-01

    This study aimed to investigate the contribution of lipid oxidation to non-enzymatic browning reactions in lipid rich model and actual food systems. Hazelnut oil and model reaction mixtures consisting of different amino acids were heated under certain conditions to determine possible lipid oxidation and non-enzymatic browning reaction products. In model systems, the Schiff base of 2,4-decadienal, its decarboxylated form, and reaction products formed after hydrolytic cleavage of the Schiff base or decarboxylated form were identified by high resolution mass spectrometry. No furosine was detected in hazelnuts after roasting at 160 °C while the concentration of free amino acids significantly decreased. 2,4-Decadienal reacted effectively with all amino acids studied through a Maillard type carbonyl-amine condensation pathway. (2E,4E)-Deca-2,4-dien-1-amine was identified as a typical reaction product in model systems and roasted hazelnuts. In lipid-rich foods like hazelnuts, lipid-derived carbonyls might be responsible for potential modifications of free and protein bound amino acids during heating.

  13. Phase diagram, thermodynamic investigations, and modelling of systems relevant to lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fuertauer, Siegfried; Beutl, Alexander; Flanorfer, Hans [Vienna Univ. (Austria). Dept. of Inorganic Chemistry - Functional Materials; Li, Dajian; Cupid, Damian [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Applied Materials - Applied Materials Physics (IAM-AWP); Henriques, David; Giel, Hans; Markus, Thorsten [Mannheim Univ. of Applied Sciences (Germany). Inst. for Thermo- and Fluiddynamics

    2017-11-15

    This article reports on two consecutive joint projects titled ''Experimental Thermodynamics and Phase Relations of New Electrode Materials for Lithium-Ion Batteries'', which were performed in the framework of the WenDeLIB 1473 priority program ''Materials with new Design for Lithium Ion Batteries''. Hundreds of samples were synthesized using experimental techniques specifically developed to deal with highly reactive lithium and lithium-containing compounds to generate electrochemical, phase diagram and crystal structure data in the Cu-Li, Li-Sn, Li-Sb, Cu-Li-Sn, Cu-Li-Sb and selected oxide systems. The thermochemical and phase diagram data were subsequently used to develop self-consistent thermodynamic descriptions of several binary systems. In the present contribution, the experimental techniques, working procedures, results and their relevance to the development of new electrode materials for lithium ion batteries are discussed and summarized. The collaboration between the three groups has resulted in more than fifteen (15) published articles during the six-year funding period.

  14. Investigations of (acid+base) equilibria in systems modelling interactions occurring in biomolecules

    International Nuclear Information System (INIS)

    Kozak, Anna; Czaja, Malgorzata; Chmurzynski, Lech

    2006-01-01

    By using the potentiometric microtitration method, acidity constants, K a , anionic, K AHA - , and cationic, K BHB + , homoconjugation constants, as well as molecular heteroconjugation, K BHA , constants have been determined in (acid+base) systems formed by the following compounds: acetic acid, phenol, n-butylamine, imidazole, and 4(5)-methylimidazole. These compounds constitute fragments of the side chains of amino acids capable of proton exchange in active sites of enzymes. The (acid+base) equilibria were studied in five polar solvents of different properties, namely in aprotic protophobic acetonitrile, acetone and propylene carbonate, in aprotic protophilic dimethyl sulfoxide and in amphiprotic methanol. The lowest values of the acidity constants of the molecular and cationic acids have been found in aprotic protophobic polar solvents - acetonitrile, propylene carbonate and acetone. Their acid strength have been found to depend on solvent basicity expressed as donor numbers, DN. These media, in particular acetonitrile and acetone, are also favourable for establishing molecular homo- and heteroconjugation equilibria. The most stable homocomplexes are formed in the case of acetic acid (K AHA - values range from 2.26 to 3.56 in these media, being more than an order of magnitude higher than those for the remaining compounds). The magnitudes of lgK BHA reveal that the most stable heterocomplexes are formed by n-butylamine and acetic acid that are characterized by the smallest differences in pK a values

  15. Investigations of (acid+base) equilibria in systems modelling interactions occurring in biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, Anna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Czaja, Malgorzata [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

    2006-05-15

    By using the potentiometric microtitration method, acidity constants, K{sub a}, anionic, K{sub AHA{sup -}}, and cationic, K{sub BHB{sup +}}, homoconjugation constants, as well as molecular heteroconjugation, K{sub BHA}, constants have been determined in (acid+base) systems formed by the following compounds: acetic acid, phenol, n-butylamine, imidazole, and 4(5)-methylimidazole. These compounds constitute fragments of the side chains of amino acids capable of proton exchange in active sites of enzymes. The (acid+base) equilibria were studied in five polar solvents of different properties, namely in aprotic protophobic acetonitrile, acetone and propylene carbonate, in aprotic protophilic dimethyl sulfoxide and in amphiprotic methanol. The lowest values of the acidity constants of the molecular and cationic acids have been found in aprotic protophobic polar solvents - acetonitrile, propylene carbonate and acetone. Their acid strength have been found to depend on solvent basicity expressed as donor numbers, DN. These media, in particular acetonitrile and acetone, are also favourable for establishing molecular homo- and heteroconjugation equilibria. The most stable homocomplexes are formed in the case of acetic acid (K{sub AHA{sup -}} values range from 2.26 to 3.56 in these media, being more than an order of magnitude higher than those for the remaining compounds). The magnitudes of lgK{sub BHA} reveal that the most stable heterocomplexes are formed by n-butylamine and acetic acid that are characterized by the smallest differences in pK{sub a} values.

  16. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model.

    Science.gov (United States)

    Bousbahi, Fatiha; Alrazgan, Muna Saleh

    2015-01-01

    To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS) to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members' acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM) for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  17. Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems

    International Nuclear Information System (INIS)

    Casalini, Stefano; Berto, Marcello; Kovtun, Alessandro; Operamolla, Alessandra; Di Rocco, Giulia; Facci, Paolo; Liscio, Andrea; Farinola, Gianluca M.; Borsari, Marco; Bortolotti, Carlo A.

    2015-01-01

    A model system for the electrochemical investigation of vectorial electron transfer in biological systems was designed, assembled and characterized. Gold electrodes, functionalized with a -OCH 3 terminated, aromatic self-assembled monolayer, were used as a substrate for the adsorption of variants of copper-containing, redox metalloprotein azurin. The engineered azurin bears a polyhistidine tag at its C-terminus. Thanks to the presence of the solvent exposed tag, which chelates Cu 2+ ions in solution, we introduced an exogenous redox centre. The different reduction potentials of the two redox centres and their positioning with respect to the surface are such that electron transfer from the exogenous copper centre and the electrode is mediated by the native azurin active site, closely paralleling electron transfer processes in naturally occurring multicentre metalloproteins.

  18. Software Engineering Support of the Third Round of Scientific Grand Challenge Investigations: Earth System Modeling Software Framework Survey

    Science.gov (United States)

    Talbot, Bryan; Zhou, Shu-Jia; Higgins, Glenn; Zukor, Dorothy (Technical Monitor)

    2002-01-01

    One of the most significant challenges in large-scale climate modeling, as well as in high-performance computing in other scientific fields, is that of effectively integrating many software models from multiple contributors. A software framework facilitates the integration task, both in the development and runtime stages of the simulation. Effective software frameworks reduce the programming burden for the investigators, freeing them to focus more on the science and less on the parallel communication implementation. while maintaining high performance across numerous supercomputer and workstation architectures. This document surveys numerous software frameworks for potential use in Earth science modeling. Several frameworks are evaluated in depth, including Parallel Object-Oriented Methods and Applications (POOMA), Cactus (from (he relativistic physics community), Overture, Goddard Earth Modeling System (GEMS), the National Center for Atmospheric Research Flux Coupler, and UCLA/UCB Distributed Data Broker (DDB). Frameworks evaluated in less detail include ROOT, Parallel Application Workspace (PAWS), and Advanced Large-Scale Integrated Computational Environment (ALICE). A host of other frameworks and related tools are referenced in this context. The frameworks are evaluated individually and also compared with each other.

  19. Application of the anisotropic phase-field crystal model to investigate the lattice systems of different anisotropic parameters and orientations

    Science.gov (United States)

    Kundin, Julia; Ajmal Choudhary, Muhammad

    2017-07-01

    In this article, we present the recent advances in the development of the anisotropic phase-field crystal (APFC) model. These advances are important in basic researches for multiferroic and thermoelectric materials with anisotropic crystal lattices and in thin-film applications. We start by providing a general description of the model derived in our previous studies based on the crystal symmetry and the microscopic dynamical density functional theory for anisotropic interactions and show that there exist only two possible degrees of freedom for the anisotropic lattices which are described by two independent parameters. New findings concerning the applications of the APFC model for the estimation of the elastic modules of anisotropic systems including sheared and stretched lattices as well as for the investigation of the heterogeneous thin film growth are described. The simulation results demonstrate the strong dependency of the misfit dislocation formation during the film growth on the anisotropy and reveal the asymmetric behavior in the cases of positive and negative misfits. We also present the development of the amplitude representation for the full APFC model of two orientation variants and show the relationship between the wave vectors and the base angles of the anisotropic lattices.

  20. Electrokinetic investigations on the system polystyrene/aqueous electrolyte solution : verification of model theories on dilute and concentrated dispersions

    NARCIS (Netherlands)

    Put, van der A.G.

    1980-01-01

    This thesis presents a systematic experimental and theoretical study on electrokinetic and electroconducting properties of disperse systems. The increasing interest in transport processes through charged porous systems has recently brought about a corresponding growth of models and theories since

  1. Disruption of Saccharomyces cerevisiae by Plantaricin 149 and investigation of its mechanism of action with biomembrane model systems.

    Science.gov (United States)

    Lopes, José Luiz S; Nobre, Thatyane M; Siano, Alvaro; Humpola, Verónica; Bossolan, Nelma R S; Zaniquelli, Maria E D; Tonarelli, Georgina; Beltramini, Leila M

    2009-10-01

    The action of a synthetic antimicrobial peptide analog of Plantaricin 149 (Pln149a) against Saccharomyces cerevisiae and its interaction with biomembrane model systems were investigated. Pln149a was shown to inhibit S. cerevisiae growth by more than 80% in YPD medium, causing morphological changes in the yeast wall and remaining active and resistant to the yeast proteases even after 24 h of incubation. Different membrane model systems and carbohydrates were employed to better describe the Pln149a interaction with cellular components using circular dichroism and fluorescence spectroscopies, adsorption kinetics and surface elasticity in Langmuir monolayers. These assays showed that Pln149a does not interact with either mono/polysaccharides or zwitterionic LUVs, but is strongly adsorbed to and incorporated into negatively charged surfaces, causing a conformational change in its secondary structure from random-coil to helix upon adsorption. From the concurrent analysis of Pln149a adsorption kinetics and dilatational surface elasticity data, we determined that 2.5 muM is the critical concentration at which Pln149a will disrupt a negative DPPG monolayer. Furthermore, Pln149a exhibited a carpet-like mechanism of action, in which the peptide initially binds to the membrane, covering its surface and acquiring a helical structure that remains associated to the negatively charged phospholipids. After this electrostatic interaction, another peptide region causes a strain in the membrane, promoting its disruption.

  2. Investigating IT Faculty Resistance to Learning Management System Adoption Using Latent Variables in an Acceptance Technology Model

    Directory of Open Access Journals (Sweden)

    Fatiha Bousbahi

    2015-01-01

    Full Text Available To enhance instruction in higher education, many universities in the Middle East have chosen to introduce learning management systems (LMS to their institutions. However, this new educational technology is not being used at its full potential and faces resistance from faculty members. To investigate this phenomenon, we conducted an empirical research study to uncover factors influencing faculty members’ acceptance of LMS. Thus, in the Fall semester of 2014, Information Technology faculty members were surveyed to better understand their perceptions of the incorporation of LMS into their courses. The results showed that personal factors such as motivation, load anxiety, and organizational support play important roles in the perception of the usefulness of LMS among IT faculty members. These findings suggest adding these constructs in order to extend the Technology acceptance model (TAM for LMS acceptance, which can help stakeholders of the university to implement the use of this system. This may assist in planning and evaluating the use of e-learning.

  3. Investigation of the effects of external current systems on the MAGSAT data utilizing grid cell modeling techniques

    Science.gov (United States)

    Klumpar, D. M. (Principal Investigator)

    1982-01-01

    The feasibility of modeling magnetic fields due to certain electrical currents flowing in the Earth's ionosphere and magnetosphere was investigated. A method was devised to carry out forward modeling of the magnetic perturbations that arise from space currents. The procedure utilizes a linear current element representation of the distributed electrical currents. The finite thickness elements are combined into loops which are in turn combined into cells having their base in the ionosphere. In addition to the extensive field modeling, additional software was developed for the reduction and analysis of the MAGSAT data in terms of the external current effects. Direct comparisons between the models and the MAGSAT data are possible.

  4. 3D stratigraphic modeling of the Congo turbidite system since 210 ka: an investigation of factors controlling sedimentation

    Science.gov (United States)

    Laurent, Dimitri; Picot, Marie; Marsset, Tania; Droz, Laurence; Rabineau, Marina; Granjeon, Didier; Molliex, Stéphane

    2017-04-01

    The geometry and internal functioning of turbidite systems are relatively well-constrained today. However, the respective role of autogenic (topographic compensation, dynamics of turbidity currents…) and allogenic factors (tectonics, sea-level, climate) governing their architectural evolution is still under debate. The geometry of the Quaternary Congo Fan is characterized by successive sedimentary prograding/retrograding cycles bounded by upfan avulsions, reflecting a periodic control of sedimentation (Picot et al., 2016). Multi-proxy studies revealed a strong interplay between autogenic control and climate forcing as evidenced by changes in fluvial sediment supplies consistent with arid and humid periods in the Congo River Basin. In the light of these results, the aim of this study is to investigate the relative impact of internal and external forcing factors controlling, both in time and space, the formation and evolution of depocenters of the Congo Deep-Sea Fan since 210 ka. This work represents the first attempt to model in 3D the stratigraphic architecture of the Congo turbidite system using DionisosFlow (IFP-EN), a diffusion process-based software. It allows the simulation of sediment transport and the 3D geometry reproduction of sedimentary units based on physical processes such as sea level changes, tectonics, sediment supply and transport. According to the modeling results, the role of topographic compensation in the deep-sea fan geometry is secondary compared to climate changes in the drainage basin. It appears that a periodic variation of sediment discharge and water flow is necessary to simulate the timing and volume of prograding/retrograding sedimentary cycles and more particularly the upfan avulsion events. The best-fit simulations show that the overriding factor for such changes corresponds to the expansion of the vegetation cover in the catchment basin associated to the Milankovitch cycle of precession which controlled the West African Monsoon

  5. Interaction of cement model systems with superplasticizers investigated by atomic force microscopy, zeta potential, and adsorption measurements.

    Science.gov (United States)

    Ferrari, Lucia; Kaufmann, Josef; Winnefeld, Frank; Plank, Johann

    2010-07-01

    Polyelectrolyte-based dispersants are commonly used in a wide range of industrial applications to provide specific workability to colloidal suspensions. Their working mechanism is based on adsorption onto the surfaces of the suspended particles. The adsorbed polymer layer can exercise an electrostatic and/or a steric effect which is responsible for achieving dispersion. This study is focused on the dispersion forces induced by polycarboxylate ether-based superplasticizers (PCEs) commonly used in concrete. They are investigated by atomic force microscopy (AFM) applying standard silicon nitride tips exposed to solutions with different ionic compositions in a wet cell. Adsorption isotherms and zeta potential analysis were performed to characterize polymer displacement in the AFM system on nonreactive model substrates (quartz, mica, calcite, and magnesium oxide) in order to avoid the complexity of cement hydration products. The results show that PCE is strongly adsorbed by positively charged materials. This fact reveals that, being silicon nitride naturally positively charged, in most cases the superplasticizer adsorbs preferably on the silicon nitride tip than on the AFM substrate. However, the force-distance curves displayed repulsive interactions between tip and substrates even when polymer was poorly adsorbed on both. These observations allow us to conclude that the dispersion due to PCE strongly depends on the particle charge. It differs between colloids adsorbing and not adsorbing PCE, and leads to different forces acting between the particles. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Investigation of Noise in Electronic Ultrasonic Systems

    Directory of Open Access Journals (Sweden)

    Paulius Adomavičius

    2011-03-01

    Full Text Available Noise models in ultrasonic control system have been investigated. Ultrasonic system channel consist of exciting generator, ultrasonic transducer, amplitude limiter, amplifier, low band filter and A/D converter. The ultrasonic transducers have been described as Von Hippel model, Van Dyke model or improved Van Dyke model. Advantages and disadvantages of these models are discussed in this paper. Noise models of amplitude limiter and linear operational amplifier are presented. The summary results of calculated noise spectral density of ultrasonic system channel have been presented.Article in Lithuanian

  7. Investigation of the effects of external current systems on the MAGSAT data utilizing grid cell modeling techniques

    Science.gov (United States)

    Klumpar, D. M. (Principal Investigator)

    1981-01-01

    Efforts devoted to reading MAGSAT data tapes in preparation for further analysis of the MAGSAT data are discussed. A modeling procedure developed to compute the magnetic fields at satellite orbit due to hypothesized current distributions in the ionosphere and magnetosphere is described. This technique utilizes a linear current element representation of the large-scale space-current system. Several examples of the model field perturbations computed along hypothetical satellite orbits are shown.

  8. Model for Investigation of Operational Wind Power Plant Regimes with Doubly–Fed Asynchronous Machine in Power System

    Directory of Open Access Journals (Sweden)

    R. I. Mustafayev

    2012-01-01

    Full Text Available The paper presents methodology for mathematical modeling of power system (its part when jointly operated with wind power plants (stations that contain asynchronous doubly-fed machines used as generators. The essence and advantage of the methodology is that it allows efficiently to mate equations of doubly-fed asynchronous machines, written in the axes that rotate with the machine rotor speed with the equations of external electric power system, written in synchronously rotating axes.

  9. Advanced Wastewater Treatment Engineering—Investigating Membrane Fouling in both Rotational and Static Membrane Bioreactor Systems Using Empirical Modelling

    Directory of Open Access Journals (Sweden)

    Parneet Paul

    2016-01-01

    Full Text Available Advanced wastewater treatment using membranes are popular environmental system processes since they allow reuse and recycling. However, fouling is a key limiting factor and so proprietary systems such as Avanti’s RPU-185 Flexidisks membrane bioreactor (MBR use novel rotating membranes to assist in ameliorating it. In earlier research, this rotating process was studied by creating a simulation model based on first principles and traditional fouling mechanisms. In order to directly compare the potential benefits of this rotational system, this follow-up study was carried out using Avanti’s newly developed static (non-rotating Flexidisks MBR system. The results from operating the static pilot unit were simulated and modelled using the rotational fouling model developed earlier however with rotational switching functions turned off and rotational parameters set to a static mode. The study concluded that a rotating MBR system could increase flux throughput when compared against a similar static system. It is thought that although the slowly rotating spindle induces a weak crossflow shear, it is still able to even out cake build up across the membrane surface, thus reducing the likelihood of localised critical flux being exceeded at the micro level and lessening the potential of rapid trans-membrane pressure increases at the macro level.

  10. Negative pressures in full-scale distribution system: field investigation, modelling, estimation of intrusion volumes and risk for public health

    Directory of Open Access Journals (Sweden)

    M. C. Besner

    2010-07-01

    Full Text Available Various investigations encompassing microbial characterization of external sources of contamination (soil and trenchwater surrounding water mains, flooded air-valve vaults, field pressure monitoring, and hydraulic and transient analyses were conducted in the same distribution system where two epidemiological studies showing an increase in gastrointestinal illness for people drinking tap water were conducted in the 1990's. Interesting results include the detection of microorganisms indicators of fecal contamination in all external sources investigated but at a higher frequency in the water from flooded air-valve vaults, and the recording of 18 negative pressure events in the distribution system during a 17-month monitoring period. Transient analysis of this large and complex distribution system was challenging and highlighted the need to consider field pressure data in the process.

  11. Investigation of the applicability of a functional programming model to fault-tolerant parallel processing for knowledge-based systems

    Science.gov (United States)

    Harper, Richard

    1989-01-01

    In a fault-tolerant parallel computer, a functional programming model can facilitate distributed checkpointing, error recovery, load balancing, and graceful degradation. Such a model has been implemented on the Draper Fault-Tolerant Parallel Processor (FTPP). When used in conjunction with the FTPP's fault detection and masking capabilities, this implementation results in a graceful degradation of system performance after faults. Three graceful degradation algorithms have been implemented and are presented. A user interface has been implemented which requires minimal cognitive overhead by the application programmer, masking such complexities as the system's redundancy, distributed nature, variable complement of processing resources, load balancing, fault occurrence and recovery. This user interface is described and its use demonstrated. The applicability of the functional programming style to the Activation Framework, a paradigm for intelligent systems, is then briefly described.

  12. A systems biology approach to investigate the mechanism of action of trabectedin in a model of myelomonocytic leukemia.

    Science.gov (United States)

    Mannarino, L; Paracchini, L; Craparotta, I; Romano, M; Marchini, S; Gatta, R; Erba, E; Clivio, L; Romualdi, C; D'Incalci, M; Beltrame, L; Pattini, L

    2018-01-01

    This study was designed to investigate the mode of action of trabectedin in myelomonocytic leukemia cells by applying systems biology approaches to mine gene expression profiling data and pharmacological assessment of the cellular effects. Significant enrichment was found in regulons of target genes inferred for specific transcription factors, among which MAFB was the most upregulated after treatment and was central in the transcriptional network likely to be relevant for the specific therapeutic effects of trabectedin against myelomonocytic cells. Using the Connectivity Map, similarity among transcriptional signatures elicited by treatment with different compounds was investigated, showing a high degree of similarity between transcriptional signatures of trabectedin and those of the topoisomerase I inhibitor, irinotecan, and an anti-dopaminergic antagonist, thioridazine. The study highlights the potential importance of systems biology approaches to generate new hypotheses that are experimentally testable to define the specificity of the mechanism of action of drugs.

  13. MUD: a Model to investigate the migration of 137Cs in the Urban environment and Drainage and sewage treatment systems.

    Science.gov (United States)

    Gallego, Eduardo

    2006-01-01

    A model is presented for the migration of 137Cs in the urban environment, including the drainage systems and the sewage treatment plants, with flexibility to be adapted to different configurations common in urban areas. The dynamics of 137Cs is simulated both under natural evolution and in case of forced decontamination, which can have a direct impact on the radioactivity going to sewers. The model assesses the activity concentrated in sewage sludge and that discharged with the treated or untreated effluent to the receiving watercourse. Tests made for two post-Chernobyl contamination scenarios in Sweden show differences between model predictions and observed results within the range of the experimental uncertainties. An uncertainty and sensitivity analysis of the main model parameters indicates that some parameters may have a significant influence on the results of the model. Moreover, the model uncertainty is driven by a few parameters; therefore, additional research could be necessary into these parameters, aiming at simplifying the model without losing its predictive power.

  14. MUD: a Model to investigate the migration of 137Cs in the Urban environment and Drainage and sewage treatment systems

    International Nuclear Information System (INIS)

    Gallego, Eduardo

    2006-01-01

    A model is presented for the migration of 137 Cs in the urban environment, including the drainage systems and the sewage treatment plants, with flexibility to be adapted to different configurations common in urban areas. The dynamics of 137 Cs is simulated both under natural evolution and in case of forced decontamination, which can have a direct impact on the radioactivity going to sewers. The model assesses the activity concentrated in sewage sludge and that discharged with the treated or untreated effluent to the receiving watercourse. Tests made for two post-Chernobyl contamination scenarios in Sweden show differences between model predictions and observed results within the range of the experimental uncertainties. An uncertainty and sensitivity analysis of the main model parameters indicates that some parameters may have a significant influence on the results of the model. Moreover, the model uncertainty is driven by a few parameters; therefore, additional research could be necessary into these parameters, aiming at simplifying the model without losing its predictive power

  15. Investigations of solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2005-01-01

    A large variety of solar combi systems are on the marked to day. The best performing systems are highly advanced energy systems with thermal stratification manifolds, an efficient boiler and only one control system, which controls both the boiler and the solar collector loop (Weiss et al., 2003......). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical...

  16. Investigations of solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa

    2005-01-01

    A large variety of solar combi systems are on the marked to day. The best performing systems are highly advanced energy systems with thermal stratification manifolds, an efficient boiler and only one control system, which controls both the boiler and the solar collector loop (Weiss et al., 2003...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical......). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more...

  17. Investigations of respiratory control systems simulation

    Science.gov (United States)

    Gallagher, R. R.

    1973-01-01

    The Grodins' respiratory control model was investigated and it was determined that the following modifications were necessary before the model would be adaptable for current research efforts: (1) the controller equation must be modified to allow for integration of the respiratory system model with other physiological systems; (2) the system must be more closely correlated to the salient physiological functionings; (3) the respiratory frequency and the heart rate should be expanded to illustrate other physiological relationships and dependencies; and (4) the model should be adapted to particular individuals through a better defined set of initial parameter values in addition to relating these parameter values to the desired environmental conditions. Several of Milhorn's respiratory control models were also investigated in hopes of using some of their features as modifications for Grodins' model.

  18. Investigating patient safety culture across a health system: multilevel modelling of differences associated with service types and staff demographics.

    Science.gov (United States)

    Gallego, Blanca; Westbrook, Mary T; Dunn, Adam G; Braithwaite, Jeffrey

    2012-08-01

    To use multilevel modelling to compare the patient safety cultures of types of services across a health system and to determine whether differences found can be accounted for by staffs' professions, organizational roles, ages and type of patient care provided. Application of a hierarchical two-level regression model. All services in the South Australian public health system. Approximately half of the health staff (n = 14 054) in the 46 organizations, classified into 18 types of service, which made up the South Australian public health system. Staff completed the Safety Attitudes Questionnaire. Attitudes regarding Teamwork Climate, Safety Climate, Job Satisfaction, Stress Recognition, Perception of Management and Working Conditions in participants' workplaces. All SAQ indices showed statistically significant although modest variations according to service type. However, most of these differences were not accounted for by the differences in the demographic composition of services' staff. Most favourable safety attitudes were found in the breast screening, primary/community health services, community nursing and metropolitan non-teaching hospitals. Poorer cultures were reported in the psychiatric hospital, mental health, metropolitan ambulance services and top-level teaching hospitals. Demographic differences in safety attitudes were observed; particularly, clinical, senior managerial, aged care and older staff held more favourable attitudes. Differences in staff attitudes have been demonstrated at a macro-level across the type of health services but for the most part, differences could not be explained by staffing composition.

  19. Seeing the Wood for the Trees: Applying the dual-memory system model to investigate expert teachers' observational skills in natural ecological learning environments

    Science.gov (United States)

    Stolpe, Karin; Björklund, Lars

    2012-01-01

    This study aims to investigate two expert ecology teachers' ability to attend to essential details in a complex environment during a field excursion, as well as how they teach this ability to their students. In applying a cognitive dual-memory system model for learning, we also suggest a rationale for their behaviour. The model implies two separate memory systems: the implicit, non-conscious, non-declarative system and the explicit, conscious, declarative system. This model provided the starting point for the research design. However, it was revised from the empirical findings supported by new theoretical insights. The teachers were video and audio recorded during their excursion and interviewed in a stimulated recall setting afterwards. The data were qualitatively analysed using the dual-memory system model. The results show that the teachers used holistic pattern recognition in their own identification of natural objects. However, teachers' main strategy to teach this ability is to give the students explicit rules or specific characteristics. According to the dual-memory system model the holistic pattern recognition is processed in the implicit memory system as a non-conscious match with earlier experienced situations. We suggest that this implicit pattern matching serves as an explanation for teachers' ecological and teaching observational skills. Another function of the implicit memory system is its ability to control automatic behaviour and non-conscious decision-making. The teachers offer the students firsthand sensory experiences which provide a prerequisite for the formation of implicit memories that provides a foundation for expertise.

  20. Investigation of Higher Brain Functions in Music Composition Using Models of the Cortex Based on Physical System Analogies.

    Science.gov (United States)

    Leng, Xiaodan

    The trion model was developed using the Mountcastle organizational principle for the column as the basic neuronal network in the cortex and the physical system analogy of Fisher's ANNNI spin model. An essential feature is that it is highly structured in time and in spatial connections. Simulations of a network of trions have shown that large numbers of quasi-stable, periodic spatial-temporal firing patterns can be excited. Characteristics of these patterns include the quality of being readily enhanced by only a small change in connection strengths, and that the patterns evolve in certain natural sequences from one to another. With only somewhat different parameters than used for studying memory and pattern recognition, much more flowing and intriguing patterns emerged from the simulations. The results were striking when these probabilistic evolutions were mapped onto pitches and instruments to produce music: For example different simple mappings of the same evolution give music having the "flavor" of a minuet, a waltz, folk music, or styles of specific periods. A theme can be learned so that evolutions have this theme and its variations reoccurring more often. That the trion model is a viable model for the coding of musical structure in human composition and perception is suggested. It is further proposed that model is relevant for examining creativity in the higher cognitive functions of mathematics and chess, which are similar to music. An even higher level of cortical organization was modeled by coupling together several trion networks. Further, one of the crucial features of higher brain function, especially in music composition or appreciation, is the role of emotion and mood as controlled by the many neuromodulators or neuropeptides. The MILA model whose underlying basis is zero-level representation of Kac-Moody algebra is used to modulate periodically the firing threshold of each network. Our preliminary results show that the introduction of "neuromodulation

  1. Investigating the Direct Meltwater Effect in Terrestrial Oxygen-Isotope Paleoclimate Records Using an Isotope-Enabled Earth System Model

    Science.gov (United States)

    Zhu, Jiang; Liu, Zhengyu; Brady, Esther C.; Otto-Bliesner, Bette L.; Marcott, Shaun A.; Zhang, Jiaxu; Wang, Xianfeng; Nusbaumer, Jesse; Wong, Tony E.; Jahn, Alexandra; Noone, David

    2017-12-01

    Variations in terrestrial oxygen-isotope reconstructions from ice cores and speleothems have been primarily attributed to climatic changes of surface air temperature, precipitation amount, or atmospheric circulation. Here we demonstrate with the fully coupled isotope-enabled Community Earth System Model an additional process contributing to the oxygen-isotope variations during glacial meltwater events. This process, termed "the direct meltwater effect," involves propagating large amounts of isotopically depleted meltwater throughout the hydrological cycle and is independent of climatic changes. We find that the direct meltwater effect can make up 15-35% of the δ18O signals in precipitation over Greenland and eastern Brazil for large freshwater forcings (0.25-0.50 sverdrup (106 m3/s)). Model simulations further demonstrate that the direct meltwater effect increases with the magnitude and duration of the freshwater forcing and is sensitive to both the location and shape of the meltwater. These new modeling results have important implications for past climate interpretations of δ18O.

  2. Atomistic modeling to investigate the favored composition for metallic glass formation in the Ca-Mg-Ni ternary system.

    Science.gov (United States)

    Zhao, S; Li, J H; An, S M; Li, S N; Liu, B X

    2017-05-17

    A realistic interatomic potential was first constructed for the Ca-Mg-Ni system and then applied to Monte Carlo simulations to predict the favored composition for metallic glass formation in the ternary system. The simulations not only predict a hexagonal composition region, within which the Ca-Mg-Ni metallic glass formation is energetically favored, but also pinpoint an optimized sub-region within which the amorphization driving force, i.e. the energy difference between the solid solution and disordered phase, is larger than that outside. The simulations further reveal that the physical origin of glass formation is the solid solution collapsing when the solute atom exceeds the critical solid solubility. Further structural analysis indicates that the pentagonal bi-pyramids dominate in the optimized sub-region. The large atomic size difference between Ca, Mg and Ni extends the short-range landscape and facilitates the development of a hybridized packing model in the medium-range, and eventually enhancing the glass formation in the system. The predictions are well supported by the experimental observations reported so far, and could be of help for designing the ternary glass formation.

  3. Investigating the effect of external trauma through a dynamic system modeling approach for clustering causality in diabetic foot ulcer development.

    Science.gov (United States)

    Salimi, Parisa; Hamedi, Mohsen; Jamshidi, Nima; Vismeh, Milad

    2017-04-01

    Diabetes and its associated complications are realized as one of the most challenging medical conditions threatening more than 29 million people only in the USA. The forecasts suggest a suffering of more than half a billion worldwide by 2030. Amid all diabetic complications, diabetic foot ulcer (DFU) has attracted much scientific investigations to lead to a better management of this disease. In this paper, a system thinking methodology is adopted to investigate the dynamic nature of the ulceration. The causal loop diagram as a tool is utilized to illustrate the well-researched relations and interrelations between causes of the DFU. The result of clustering causality evaluation suggests a vicious loop that relates external trauma to callus. Consequently a hypothesis is presented which localizes development of foot ulceration considering distribution of normal and shear stress. It specifies that normal and tangential forces, as the main representatives of external trauma, play the most important role in foot ulceration. The evaluation of this hypothesis suggests the significance of the information related to both normal and shear stress for managing DFU. The results also discusses how these two react on different locations on foot such as metatarsal head, heel and hallux. The findings of this study can facilitate tackling the complexity of DFU problem and looking for constructive mitigation measures. Moreover they lead to developing a more promising methodology for managing DFU including better prognosis, designing prosthesis and insoles for DFU and patient caring recommendations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Modeling tools for an Integrated River-Delta-Sea system investigation: the Pan-European Research Infrastructure DANUBIUS-RI philosophy

    Science.gov (United States)

    Umgiesser, Georg; Bellafiore, Debora; De Pascalis, Francesca; Icke, Joost; Stanica, Adrian

    2017-04-01

    The DANUBIUS Research Infrastructure (DANUBIUS-RI) is a new initiative to address the challenges and opportunities of research on large river- sea (RS) systems. DANUBIUS-RI is a distributed pan-European RI that will provide a platform for interdisciplinary research. It will deal with RS investigation through facilities and expertise from a large number of European institutions becoming a 'one-stop shop' for knowledge exchange in managing RS systems, ranging from freshwater to marine research. Globally, RS systems are complex and dynamic, with huge environmental, social and economic value. They are poorly understood but under increasing pressure through pollution, hydraulic engineering, water supply, energy, flood control and erosion. RS systems in Europe are among the most impacted globally, after centuries of industrialisation, urbanisation and agricultural intensification. Improved understanding is essential to avoid irreversible degradation and for restoration. DANUBIUS-RI will provide, among a number of other facilities concerning observations, analyses, impacts' evaluation, a modeling node that will provide integrated up-to-date tools, at locations of high scientific importance and opportunity, covering the RS systems - from source (upper parts of rivers - mountain lakes) to the transition with coastal seas. Modeling will be one of the major services provided by DANUBIUS-RI, relying on the inputs from the whole RI. RS systems are challenging from a modelling point of view, because of the complex morphology and the wide temporal and spatial range of processes occurring. Scale interaction plays a central role, considering the different hydro-eco-morphological processes on the large (basin) and small (local, coast, rivers, lagoons) scale. Currently, different model applications are made for the different geographical domains, and also for subsets of the processes. For instance there are separate models for rainfall runoff in the catchment, a sewer model for the

  5. The Investigation of TLC Model Checker Properties

    Directory of Open Access Journals (Sweden)

    Vadym Viktorovych Shkarupylo

    2016-06-01

    Full Text Available This paper presents the investigation and comparison of TLC model checking method (TLA Checker properties. There are two different approaches to method usage which are considered. The first one consists of a transition system states attendance by breadth-first search (BFS, and the second one by depth-first search (DFS. The Kripke structure has been chosen as a transition system model. A case study has been conducted, where composite web service usage scenario has been considered. Obtained experimental results are aimed at increasing the effectiveness of TLA+ specifications automated verification.

  6. Applying Machine Trust Models to Forensic Investigations

    Science.gov (United States)

    Wojcik, Marika; Venter, Hein; Eloff, Jan; Olivier, Martin

    Digital forensics involves the identification, preservation, analysis and presentation of electronic evidence for use in legal proceedings. In the presence of contradictory evidence, forensic investigators need a means to determine which evidence can be trusted. This is particularly true in a trust model environment where computerised agents may make trust-based decisions that influence interactions within the system. This paper focuses on the analysis of evidence in trust-based environments and the determination of the degree to which evidence can be trusted. The trust model proposed in this work may be implemented in a tool for conducting trust-based forensic investigations. The model takes into account the trust environment and parameters that influence interactions in a computer network being investigated. Also, it allows for crimes to be reenacted to create more substantial evidentiary proof.

  7. Soft-linking energy systems and GIS models to investigate spatial hydrogen infrastructure development in a low-carbon UK energy system

    International Nuclear Information System (INIS)

    Strachan, Neil; Hughes, Nick; Balta-Ozkan, Nazmiye; McGeevor, Kate; Joffe, David

    2009-01-01

    This paper describes an innovative modelling approach focusing on linking spatial (GIS) modelling of hydrogen (H 2 ) supply, demands and infrastructures, anchored within a economy-wide energy systems model (MARKAL). The UK government is legislating a groundbreaking climate change mitigation target for a 60% CO 2 reduction by 2050, and has identified H 2 infrastructures and technologies as potentially playing a major role, notably in the transport sector. An exploratory set of linked GIS-MARKAL model scenarios generate a range of nuanced insights including spatial matching of supply and demand for optimal zero-carbon H 2 deployment, a crucial finding on successive clustering of demand centres to enable economies of scale in H 2 supply and distribution, the competitiveness of imported liquid H 2 and of liquid H 2 distribution, and sectoral competition for coal with carbon sequestration between electricity and H 2 production under economy-wide CO 2 constraints. (author)

  8. Investigating Surface Bias Errors in the Weather Research and Forecasting (WRF) Model using a Geographic Information System (GIS)

    Science.gov (United States)

    2015-02-01

    Mlawer et al. 1997) is used for long wave radiation and the Dudhia (1989) scheme for shortwave radiation . The Noah land surface model (Chen and...decreases the background turbulent kinetic energy and alters the diagnosis of the boundary layer depth used for model output and data assimilation...Kain 2004) cumulus parameterization is used only on the 9-km outer domain. For radiation , the Rapid Radiative Transfer Model (RRTM) parameterization

  9. A Structural Model for Students' Adoption of Learning Management Systems: An Empirical Investigation in the Higher Education Context

    Science.gov (United States)

    Findik-Coskunçay, Duygu; Alkis, Nurcan; Özkan-Yildirim, Sevgi

    2018-01-01

    With the recent advances in information technologies, Learning Management Systems have taken on a significant role in providing educational resources. The successful use of these systems in higher education is important for the implementation, management and continuous improvement of e-learning services to increase the quality of learning. This…

  10. Using the forest, people, fire agent-based social network model to investigate interactions in social-ecological systems

    Science.gov (United States)

    Paige Fischer; Adam Korejwa; Jennifer Koch; Thomas Spies; Christine Olsen; Eric White; Derric Jacobs

    2013-01-01

    Wildfire links social and ecological systems in dry-forest landscapes of the United States. The management of these landscapes, however, is bifurcated by two institutional cultures that have different sets of beliefs about wildfire, motivations for managing wildfire risk, and approaches to administering policy. Fire protection, preparedness, and response agencies often...

  11. Spontaneous transformation of murine oviductal epithelial cells: A model system to investigate the onset of fallopian-derived tumors

    Directory of Open Access Journals (Sweden)

    MIchael P. Endsley

    2015-07-01

    Full Text Available High-grade serous carcinoma (HGSC is the most lethal ovarian cancer histotype. The fallopian tube secretory epithelial cells (FTSECs are a proposed progenitor cell type. Genetically altered FTSECs form tumors in mice; however, a spontaneous HGSC model has not been described. Apart from a subpopulation of genetically predisposed women, most women develop ovarian cancer spontaneously, which is associated with aging and lifetime ovulations. A murine oviductal cell line (MOELOW was developed and continuously passaged in culture to mimic cellular aging (MOEHIGH. The MOEHIGH cellular model exhibited a loss of acetylated tubulin consistent with an outgrowth of secretory epithelial cells in culture. MOEHIGH cells proliferated significantly faster than MOELOW, and the MOEHIGH cells produced more 2D foci and 3D soft agar colonies as compared to MOELOW. MOEHIGH were xenografted into athymic female nude mice both in the subcutaneous and the intraperiteonal compartments. Only the subcutaneous grafts formed tumors that were negative for cytokeratin, but positive for oviductal markers such as oviductal glycoprotein 1 and Pax8. These tumors were considered to be poorly differentiated carcinoma. The differential molecular profiles between MOEHIGH and MOELOW were determined using RNA-Seq and confirmed by protein expression to uncover pathways important in transformation, like the p53 pathway, the FOXM1 pathway, WNT signaling, and splicing. MOEHIGH had enhanced protein expression of c-myc, Cyclin E, p53 and FOXM1 with reduced expression of p21. MOEHIGH were also less sensitive to cisplatin and DMBA, which induce lesions typically repaired by base-excision repair. A model of spontaneous tumorogenesis was generated starting with normal oviductal cells. Their transition to cancer involved alterations in pathways associated with high-grade serous cancer in humans.

  12. An aggregate model of grid-connected, large-scale, offshore wind farm for power stability investigations-importance of windmill mechanical system

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, H.

    2002-01-01

    . Because the shaft system gives a soft coupling between the rotating wind turbine and the induction generator, the large-scale wind farm cannot always be reduced to one-machine equivalent and use of multi-machine equivalents will be necessary for reaching accuracy of the investigation results....... This will be in cases with irregular wind distribution over the wind farm area. The torsion mode of the shaft systems of large wind turbines is commonly in the range of 1-2 Hz and close to typical values of the electric power grid eigenfrequencies why there is a risk of oscillation between the wind turbines...... and the entire network. All these phenomena are different compared to previous experiences with modelling of conventional power plants with synchronous generators and stiff shaft systems....

  13. Effects of propagule density and survival strategies on establishment and growth: further investigations in the phylloplane fungal model system.

    Science.gov (United States)

    Nix-Stohr, Shannon; Moshe, Riina; Dighton, John

    2008-01-01

    This work builds on an earlier culture study where we determined that species diversity of competing saprotrophic phyllpolane fungi had only a negligible effect on the establishment and coexistence of a target fungus, Pestalotia vaccinii. Here, we explore preliminary evidence suggesting that spore density is a more important contributing factor to colonization and coexistence. We examine the influence of propagule density in vitro on establishment and growth of select members of the phylloplane of Vaccinium macrocarpon (American cranberry). To evaluate the response of the weak pathogen P. vaccinii to changes in competitors spore density, we chose saprotrophs from the previous investigation that had the greatest inhibitory effect on the establishment of P. vaccinii (Curvularia lunata), an intermediate inhibitory effect (Alternaria alternata) and the least inhibitory effect (Penicillium sp.). A constant target spore concentration of 50 viable spores of P. vaccinii was pit against densities of the three individual competitors ranging between 12 and 200 spores. As viable propagule density increased, establishment and coexistence of P. vaccinii significantly decreased, with C. lunata and A. alternata decreasing the growth of P. vaccinii more than Penicillium sp. Concomitantly, both C. lunata and Penicillium sp. were not significantly affected by overall spore density but were significantly affected by the presence of P. vaccinii. A. alternata, on the other hand, was not significantly influenced by the presence of P. vaccinii but was significantly affected by overall spore density. An in vitro investigation into the effect of interspecific competition on mycelial growth suggests how different survival strategies and community assembly rules might influence both growth and development. Growth of P. vaccinii was significantly less when interacting with C. lunata than when interacting with either A. alternata or Penicillium sp. Conversely, P. vaccinii had the greatest

  14. Model systems with extreme aspect ratio, tunable geometry, and surface functionality for a quantitative investigation of the Lotus effect.

    Science.gov (United States)

    Hassel, Achim Walter; Milenkovic, Srdjan; Schürmann, Ulrich; Greve, Henry; Zaporojtchenko, Vladimir; Adelung, Rainer; Faupel, Franz

    2007-02-13

    Superhydrophobicity and superhydrophilicity of surfaces are key properties for fabrication of self-cleaning surfaces (Lotus effect). It is well known that the mechanism behind this is based on the surface roughness and surface functionalization. To obtain an understanding of the details of the underlying mechanism, a metal system based on a eutectic is suggested. In this study, a wide range tunability of its needlelike narrow size distributed nanostructure is demonstrated. The length of the needles as well as their density can be varied independently. In addition, an important parameter for the wettability, the roughness, is related directly to the growth parameters, which lead to excellent controllable and reproducible eutectic structures. Simply by varying etching time very high aspect ratios can be achieved, allowing studying the interaction of the very long needles with liquids. Moreover, the surface functionality can be tuned by RF-magnetron sputtering of PTFE onto the metal needles. As those layers can be very thin, our system allows, in principle, studying the transition from a metal to a polymer surface using submonolayers. Furthermore, the first contact angle measurements on the nanostructured and functionalized eutectic structures are presented and discussed.

  15. Methods of respiratory system investigation

    International Nuclear Information System (INIS)

    Rozenshtraukh, L.C.; Rybakova, N.I.; Vinner, M.G.

    1987-01-01

    Different methods of chest organs investigation are discussed in detail: roentgenoscopy, roentgenography, tomography and others. A detailed roentgenologic semiotics of every method is presented, as well as their comparative evaluation

  16. Numerical investigations in mixed friction systems

    Directory of Open Access Journals (Sweden)

    A Albers

    2016-09-01

    Full Text Available A numerical approach is here selected to investigate mixed friction phenomena where testing rigs cannot be used or need complex adaptations to deliver reliable measurements. The following work focuses on the numerical investigations of mixed friction systems combining fluid-solid and solid-solid interactions at the micro scale. Goal is to improve the accuracy of future macro models by applying them more precise boundary conditions derived from micro models. A three dimensional model is built in a Finite Elements (FE software composed of one fluid lubricating two sliding rough surfaces. Both surfaces are generated according to a statistical method making use of measured technical surfaces. To model the interactions between the fluid and the solid structure, the Arbitrary-Lagrangian-Eulerian remeshing process is used. A model is built, based on an axial floating bearing on which the adhesion effects are the most present. Global friction coefficient between both lubricated solids is established using the FE solver and solid-solid friction can be separated from the fluid-solid friction with further post-processing operations.

  17. Investigating accident causation through information network modelling.

    Science.gov (United States)

    Griffin, T G C; Young, M S; Stanton, N A

    2010-02-01

    Management of risk in complex domains such as aviation relies heavily on post-event investigations, requiring complex approaches to fully understand the integration of multi-causal, multi-agent and multi-linear accident sequences. The Event Analysis of Systemic Teamwork methodology (EAST; Stanton et al. 2008) offers such an approach based on network models. In this paper, we apply EAST to a well-known aviation accident case study, highlighting communication between agents as a central theme and investigating the potential for finding agents who were key to the accident. Ultimately, this work aims to develop a new model based on distributed situation awareness (DSA) to demonstrate that the risk inherent in a complex system is dependent on the information flowing within it. By identifying key agents and information elements, we can propose proactive design strategies to optimize the flow of information and help work towards avoiding aviation accidents. Statement of Relevance: This paper introduces a novel application of an holistic methodology for understanding aviation accidents. Furthermore, it introduces an ongoing project developing a nonlinear and prospective method that centralises distributed situation awareness and communication as themes. The relevance of findings are discussed in the context of current ergonomic and aviation issues of design, training and human-system interaction.

  18. A Regular Production-Remanufacturing Inventory Model for a Two-Echelon System with Price-dependent Return Rate and Environmental Effects Investigation

    Science.gov (United States)

    Dwicahyani, A. R.; Jauhari, W. A.; Jonrinaldi

    2017-06-01

    Product take-back recovery has currently became a promising effort for companies in order to create a sustainable supply chain. In addition, some restrictions including government regulations, social-ethical responsibilities, and up to economic factors have contributed to the reasons for the importance of product take-back recovery. This study aims to develop an inventory model in a system of reverse logistic management consisting of a manufacturer and a collector. Recycle dealer collects used products from the market and ships it to manufacturer. Manufacturer then recovers the used products and sell it eventually to the market. Some recovered products that can not be recovered as good as new one will be sold to the secondary market. In this study, we investigate the effects of environmental factors including GHG emissions and energy usage from transportation, regular production, and remanufacturing operations conducted by manufacturer and solve the model to get the maximum annual joint total profit for both parties. The model also considers price-dependent return rate and determine it as a decision variable as well as number of shipments from collector to manufacturer and optimal cycle period. An iterative procedure is proposed to determine the optimal solutions. We present a numerical example to illustrate the application of the model and perform a sensitivity analysis to study the effects of the changes in environmental related costs on the model’s decision.

  19. System for the academic investigation

    Directory of Open Access Journals (Sweden)

    Laura Leticia Laurent Martinez

    2005-08-01

    Full Text Available Generally, documental research depends on written bibliographical note cards that help find important text for a given research.However, the manual search for frequently used data such as author, publisher, topic, gets complicated as records increase resulting in a time consuming process that hinders the desired brainstorming.The software here presented solves two main issues: it allows a smoother and quicker data entry, and the flexibility to search by multiple criteria matching information for a specific author, publisher, topic, subtopic and date.The software also eases text transcription and builds the documental references that will be cited on research papers.The software is based on the object oriented (OO programming philosophy using Microsoft Access as a widely used relational database system.

  20. High-field EPR investigations of Mn(III)Mn(IV) and Mn(II)Mn(III) states of dimanganese catalase and related model systems.

    Science.gov (United States)

    Teutloff, Christian; Schäfer, Kai-Oliver; Sinnecker, Sebastian; Barynin, Vladimir; Bittl, Robert; Wieghardt, Karl; Lendzian, Friedhelm; Lubitz, Wolfgang

    2005-11-01

    Multi-frequency EPR experiments at 9, 34 and 94 GHz are reported on the antiferromagnetically coupled mixed valence Mn(II)Mn(III) complex of manganese catalase and on several dinuclear manganese model systems. They are compared with similar experiments obtained earlier for the Mn(III)Mn(IV) states. It is demonstrated how accurate information on the G- and 55Mn hyperfine tensors can be derived from this approach. Furthermore, the effect of oxidation state, planarity of the manganese-oxygen core and the type of ligands bridging the manganese ions on the magnetic resonance parameters and the related electronic structure is investigated. 'Broken-symmetry' density functional calculations on two Mn(III)Mn(IV) complexes, including the superoxidized state of the catalase, are presented. The agreement between calculated and experimental EPR parameters and complex geometries is remarkably good. Implications of these results for the structure and function of the dimanganese catalase are discussed. Copyright 2005 John Wiley & Sons, Ltd

  1. Investigation of an inventory calculation model for a solvent extraction system and the development of its computer programme - SEPHIS-J

    International Nuclear Information System (INIS)

    Ihara, Hitoshi; Nishimura, Hideo; Ikawa, Koji; Ido, Masaru.

    1986-11-01

    In order to improve the applicability of near-real-time materials accountancy (N.R.T.MA) to a reprocessing plant, it is necessary to develop an estimation method for the nuclear material inventory at a solvent extraction system under operation. For designing the solvent extraction system, such computer codes as SEPHIS, SOLVEX and TRANSIENTS had been used. Accuracy of these codes in tracing operations and predicting inventories in the extraction system had been discussed. Then, much better codes, e.g., SEPHIS Mod4 and PUBG, were developed. Unfortunately, SEPHIS Mod4 was not available in countries other than the USA and PUBG was not suitable for use with a mini-computer which would be practical as a field computer because of quite a lot of computing time needed. The authors investigated an inventory estimation model compatible with PUBG in functions and developed the corresponding computer programme, SEPHIS-J, based on the SEPHIS Mod3 code, resulting in a third of computing time compared with PUBG. They also validated the programme by calculating a static state as well as a dynamic one of the solvent extraction process and by comparing them among the programme, SEPHIS Mod3 and PUBG. Using the programme, it was shown that the inventory changes due to changes of feed flow and concentration were not so small that they might be neglected although the changes of feed flow and concentration were within measurement errors. (author)

  2. Modeling Complex Systems

    International Nuclear Information System (INIS)

    Schreckenberg, M

    2004-01-01

    This book by Nino Boccara presents a compilation of model systems commonly termed as 'complex'. It starts with a definition of the systems under consideration and how to build up a model to describe the complex dynamics. The subsequent chapters are devoted to various categories of mean-field type models (differential and recurrence equations, chaos) and of agent-based models (cellular automata, networks and power-law distributions). Each chapter is supplemented by a number of exercises and their solutions. The table of contents looks a little arbitrary but the author took the most prominent model systems investigated over the years (and up until now there has been no unified theory covering the various aspects of complex dynamics). The model systems are explained by looking at a number of applications in various fields. The book is written as a textbook for interested students as well as serving as a comprehensive reference for experts. It is an ideal source for topics to be presented in a lecture on dynamics of complex systems. This is the first book on this 'wide' topic and I have long awaited such a book (in fact I planned to write it myself but this is much better than I could ever have written it!). Only section 6 on cellular automata is a little too limited to the author's point of view and one would have expected more about the famous Domany-Kinzel model (and more accurate citation!). In my opinion this is one of the best textbooks published during the last decade and even experts can learn a lot from it. Hopefully there will be an actualization after, say, five years since this field is growing so quickly. The price is too high for students but this, unfortunately, is the normal case today. Nevertheless I think it will be a great success! (book review)

  3. Proteome analysis of mouse model systems: A tool to model human disease and for the investigation of tissue-specific biology.

    Science.gov (United States)

    Kislinger, Thomas; Gramolini, Anthony O

    2010-10-10

    The molecular dissections of the mechanistic pathways involved in human disease have always relied on the use of model organisms. Among the higher mammalian organisms, the laboratory mouse (Mus musculus) is the most widely used model. A large number of commercially-available, inbred strains are available to the community, including an ever growing collection of transgenic, knock-out, and disease models. Coupled to availability is the fact that animal colonies can be kept under standardized housing condition at most major universities and research institutes, with relative ease and cost efficiency (compared to larger vertebrates). As such, mouse models to study human biology and disease remains extremely attractive. In the current review we will provide an historic overview of the use of mouse models in proteome research with a focus on general tissue and organelle biology, comparative proteomics of human and mouse and the use of mouse models to study cardiac disease. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  4. Computer Profiling Based Model for Investigation

    OpenAIRE

    Neeraj Choudhary; Nikhil Kumar Singh; Parmalik Singh

    2011-01-01

    Computer profiling is used for computer forensic analysis, and proposes and elaborates on a novel model for use in computer profiling, the computer profiling object model. The computer profiling object model is an information model which models a computer as objects with various attributes and inter-relationships. These together provide the information necessary for a human investigator or an automated reasoning engine to make judgments as to the probable usage and evidentiary value of a comp...

  5. Development of next generation code system as an engineering modeling language (5). Investigation on restructuring method of conventional codes into two-layer system

    International Nuclear Information System (INIS)

    Yokoyama, Kenji

    2006-10-01

    A proposed method for gradually restructuring to the two-level system of next generation analysis system by reusing the conventional analysis system, called 'incremental method', was applied and evaluated. The following functions were selected for the evaluation: Neutron diffusion calculation for the three-dimensional XYZ system based on finite differential method, and input utilities of the cross-section data file used in the conventional system. In order to evaluate the effect of the restructuring, 'Module Coupling Index (MCI)' and 'McCabe's Cyclomatic Complexity (MCC)' were used for quantifying the quality of the modular design and the complexity of the program sequence of each module. Although MCIs of each module before restructuring were mainly 6 - 7 degrees, it was possible to reduce them to under 4 degrees in most module by restructuring with the incremental method. And, it is found that the modules under 4 degrees of MCI can be easily combined with different programming languages, which are necessary for building the two-layer system. In the meantime, MCCs in most module before restructuring were over 20 and some were over 50. The incremental method could reduce them to under 10 when C++ was used, and reduce them to under 20 when FORTRAN was used. It is correspondent to reduction of the error frequency occurred in its modification from 20 - 40% to 5 - 10%. The total number of MCC could be reduced to 1/3 when C++ was used, and to 1/2 when FORTRAN was used. By using the restructured functions in the present study and some previously developed functions, a reactor analysis tool was systematized and applied to criticality analysis of the Experimental Fast Reactor 'JOYO' MR-I. In addition, the following two functionality expansion tests were performed: To add cross section direct perturbation functionality, and to add control rod criticality position search functionality. In the tests, both the functionality expansions were carried out satisfying the condition

  6. Investigating the Role of Biogeochemical Processes in the Northern High Latitudes on Global Climate Feedbacks Using an Efficient Scalable Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Atul K. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2016-09-14

    The overall objectives of this DOE funded project is to combine scientific and computational challenges in climate modeling by expanding our understanding of the biogeophysical-biogeochemical processes and their interactions in the northern high latitudes (NHLs) using an earth system modeling (ESM) approach, and by adopting an adaptive parallel runtime system in an ESM to achieve efficient and scalable climate simulations through improved load balancing algorithms.

  7. Two Activities with a Simple Model of the Solar System: Discovering Kepler's 3rd Law and Investigating Apparent Motion of Venus

    Science.gov (United States)

    Rovšek, Barbara; Guštin, Andrej

    2018-01-01

    An astronomy "experiment" composed of three parts is described in the article. Being given necessary data a simple model of inner planets of the solar system is made in the first part with planets' circular orbits using appropriate scale. In the second part revolution of the figurines used as model representations of the planets along…

  8. Social Context, Self-Perceptions and Student Engagement: A SEM Investigation of the Self-System Model of Motivational Development (SSMMD)

    Science.gov (United States)

    Dupont, Serge; Galand, Benoit; Nils, Frédéric; Hospel, Virginie

    2014-01-01

    Introduction: The present study aimed to test a theoretically-based model (the self-system model of motivational development) including at the same time the extent to which the social context provides structure, warmth and autonomy support, the students' perceived autonomy, relatedness and competence, and behavioral, cognitive and emotional…

  9. An investigation to evaluate the analgesic and central nervous system depressant activities of Solanum nigrum (Linn. in Homoeopathic potencies in experimental animal models

    Directory of Open Access Journals (Sweden)

    Echur Natarajan Sundaram

    2015-01-01

    Full Text Available Background and Objective: In Homoeopathy, Solanum nigrum is clinically used in the treatment of ergotism, meningitis, irritation during dentition and some of the symptoms of neurological disorders but its Central Nervous System (CNS potential has not been explored experimentally yet. Therefore, a preliminary study was conducted with an objective to evaluate the analgesic and CNS depressant effects of homoeopathic potencies of S. nigrum in experimental animal models. Materials and Methods: The study was conducted in Wistar albino rats using a hot plate, ice plate and Randall-Selitto assay for analgesic; rota-rod and open field test for CNS depressant activities. The different potencies (3X, 6X, 12X and 30C of Solanum nigrum were administered orally (0.5 ml/rat/day for 30 days and response was assessed after 30 minutes of drug administration on 10 th , 20 th and 30 th day. Results: The result shows that all the four potencies of Solanum nigrum has increased the latency time required to raise and lick the paws for thermal sensation on hot plate test and for cold sensation on ice plate test and also increased the degree of threshold pressure to mechanically induced pain on Randall-Selitto assay but depressed the motor coordination and locomotor activities. Conclusion: The result obtained from this preliminary study suggests that homoeopathic preparation of Solanum nigrum in different potencies possess analgesic and CNS depressant activities. Further detailed investigations are required for its possible human use.

  10. Stability investigation of quadratic systems with delay

    Directory of Open Access Journals (Sweden)

    Vladimir Davydov

    2000-01-01

    Full Text Available Systems of differential equations with quadratic right-hand sides with delay are considered in the paper. Compact matrix notation form is proposed for the systems of such type. Stability investigations are performed by Lyapunov's second method with functions of quadratic form. Stability conditions of quadratic systems with delay, uniformly by argument deviation, and with delay depending on the system's parameters are derived. A guaranteed radius of the ball of asymptotic stability region for zero solution is obtained.

  11. Mathematical modeling of aeroelastic systems

    Science.gov (United States)

    Velmisov, Petr A.; Ankilov, Andrey V.; Semenova, Elizaveta P.

    2017-12-01

    In the paper, the stability of elastic elements of a class of designs that are in interaction with a gas or liquid flow is investigated. The definition of the stability of an elastic body corresponds to the concept of stability of dynamical systems by Lyapunov. As examples the mathematical models of flowing channels (models of vibration devices) at a subsonic flow and the mathematical models of protective surface at a supersonic flow are considered. Models are described by the related systems of the partial differential equations. An analytic investigation of stability is carried out on the basis of the construction of Lyapunov-type functionals, a numerical investigation is carried out on the basis of the Galerkin method. The various models of the gas-liquid environment (compressed, incompressible) and the various models of a deformable body (elastic linear and elastic nonlinear) are considered.

  12. Measuring the success of business-intelligence systems in South Africa: An empirical investigation applying the DeLone and McLean Model

    Directory of Open Access Journals (Sweden)

    Taurayi Mudzana

    2015-12-01

    Full Text Available Background: Business intelligence systems (BIS hold promise for improving organisational decision-making in South Africa. Yet, the use of BIS has been associated with a number of challenges. Objectives: The aim of the study was to identify post implementation factors that contribute to the success of BIS in South African organisations. Method: This study draws on the DeLone and McLean Model of Information Systems success and recent literature on business-intelligence (BI to develop and test a BIS success model. A quantitative study was conducted in the form of a survey of 102 BI users to validate the BIS success model. Results: Five interrelated factors of BIS success were confirmed. The study found that the quality of information has a strong influence on system use and user satisfaction. It was found that system quality is positively associated with user satisfaction. The results also indicated that service quality is negatively related to user satisfaction. The study also found that user satisfaction is positively associated with nett benefits of a BI system. Conclusion: The study provides insights for both managers and practitioners on the factors to focus on when implementing BIS thereby minimising the adoption risks associated with BI failures.

  13. MODEL FOR ELECTRIC LOAD OF COMMUNITY HOUSING PROJECTS TO INVESTIGATE “GENERATOR – ACCUMULATOR – CONSUMER” SYSTEM WHILE USING MONTE-CARLO METHOD

    Directory of Open Access Journals (Sweden)

    K. V. Dobrego

    2017-01-01

    Full Text Available Nowadays we observe rather rapid growth of energy accumulators market. There are prerequisites to their extensive application in Belarus. In spite of technology development problems pertaining to optimization of electric power and their operation under conditions of specific systems “generator – accumulator – consumer” (GAC have not obtained proper consideration. At the same time tuning and optimization of the GAC system may provide competitive advantages to various accumulating systems because application of accumulator batteries in non-optimal charge – discharge conditions reduces its operating resource. Optimization of the GAC system may include utilization of hybrid accumulator systems together with heterogeneous chemical and mechanical accumulators, tuning of system controller parameters etc. Research papers present a great number of empirical and analytical methods for calculation of electric loads. These methods use the following parameters as initial data: time-averaged values of actual electric power consumption, averaged apartment electric loads, empirical and statistical form coefficients, coefficients of maximum electric load for a group of uniform consumers. However such models do not meet the requirements of detailed simulation of relatively small system operation when the simulation must correspond to non-stationary, non-averaged, stochastic load nature. The paper provides a simple approach to the detailed simulation of electric loads in regard to small projects such as multi-unit apartment building or small agricultural farm. The model is formulated both in physical and algorithmic terms that make it possible to be easily realized in any programming environment. The paper presents convergence of integral electric power consumption, which is set by the model, to statistically averaged parameters. Autocorrelation function has been calculated in the paper that shows two scales for autocorrelation of simulated load diagrams

  14. Modeling of System Families

    National Research Council Canada - National Science Library

    Feiler, Peter

    2007-01-01

    .... The Society of Automotive Engineers (SAE) Architecture Analysis & Design Language (AADL) is an industry-standard, architecture-modeling notation specifically designed to support a component- based approach to modeling embedded systems...

  15. Modelling Railway Interlocking Systems

    DEFF Research Database (Denmark)

    Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth

    2000-01-01

    In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...

  16. Aerodynamic and Mechanical System Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix

    This thesis deals with mechanical multibody-systems applied to the drivetrain of a 500 kW wind turbine. Particular focus has been on gearbox modelling of wind turbines. The main part of the present project involved programming multibody systems to investigate the connection between forces, moments...

  17. An Observing System Simulation Experiment (OSSE) Investigating the OMI Aerosol Products Using Simulated Aerosol and Atmospheric Fields from the NASA GEOS-5 Model

    Science.gov (United States)

    Colarco, P. R.; Gasso, S.; Jethva, H. T.; Buchard, V.; Ahn, C.; Torres, O.; daSilva, A.

    2016-12-01

    Output from the NASA Goddard Earth Observing System, version 5 (GEOS-5) Earth system model is used to simulate the top-of-atmosphere 354 and 388 nm radiances observed by the Ozone Monitoring Instrument (OMI) onboard the Aura spacecraft. The principle purpose of developing this simulator tool is to compute from the modeled fields the so-called OMI Aerosol Index (AI), which is a more fundamental retrieval product than higher level products such as the aerosol optical depth (AOD) or absorbing aerosol optical depth (AAOD). This lays the groundwork for eventually developing a capability to assimilate either the OMI AI or its radiances, which would provide further constraint on aerosol loading and absorption properties for global models. We extend the use of the simulator capability to understand the nature of the OMI aerosol retrieval algorithms themselves in an Observing System Simulation Experiment (OSSE). The simulated radiances are used to calculate the AI from the modeled fields. These radiances are also provided to the OMI aerosol algorithms, which return their own retrievals of the AI, AOD, and AAOD. Our assessment reveals that the OMI-retrieved AI can be mostly harmonized with the model-derived AI given the same radiances provided a common surface pressure field is assumed. This is important because the operational OMI algorithms presently assume a fixed pressure field, while the contribution of molecular scattering to the actual OMI signal in fact responds to the actual atmospheric pressure profile, which is accounted for in our OSSE by using GEOS-5 produced atmospheric reanalyses. Other differences between the model and OMI AI are discussed, and we present a preliminary assessment of the OMI AOD and AAOD products with respect to the known inputs from the GEOS-5 simulation.

  18. Investigating soil moisture-climate interactions with prescribed soil moisture experiments: an assessment with the Community Earth System Model (version 1.2)

    Science.gov (United States)

    Hauser, Mathias; Orth, René; Seneviratne, Sonia I.

    2017-04-01

    Land surface hydrology is an important control of surface weather and climate. A valuable technique to investigate this link is the prescription of soil moisture in land surface models, which leads to a decoupling of the atmosphere and land processes. Diverse approaches to prescribe soil moisture, as well as different prescribed soil moisture conditions have been used in previous studies. Here, we compare and assess four methodologies to prescribe soil moisture and investigate the impact of two different estimates of the climatological seasonal cycle used to prescribe soil moisture. Our analysis shows that, though in appearance similar, the different approaches require substantially different long-term moisture inputs and lead to different temperature signals. The smallest influence on temperature and the water balance is found when prescribing the median seasonal cycle of deep soil liquid water, whereas the strongest signal is found when prescribing soil liquid and soil ice using the mean seasonal cycle. These results indicate that induced net water-balance perturbations in experiments investigating soil moisture-climate coupling are important contributors to the climate response, in addition to the intended impact of the decoupling. These results help to guide the set-up of future experiments prescribing soil moisture, as for instance planned within the Land Surface, Snow and Soil Moisture Model Intercomparison Project (LS3MIP).

  19. Hydrogel-Embedded Model Photocatalytic System Investigated by Raman and IR Spectroscopy Assisted by Density Functional Theory Calculations and Two-Dimensional Correlation Analysis.

    Science.gov (United States)

    Geitner, Robert; Götz, Stefan; Stach, Robert; Siegmann, Michael; Krebs, Patrick; Zechel, Stefan; Schreyer, Kristin; Winter, Andreas; Hager, Martin D; Schubert, Ulrich S; Gräfe, Stefanie; Dietzek, Benjamin; Mizaikoff, Boris; Schmitt, Michael; Popp, Jürgen

    2018-03-15

    The presented study reports the synthesis and the vibrational spectroscopic characterization of different matrix-embedded model photocatalysts. The goal of the study is to investigate the interaction of a polymer matrix with photosensitizing dyes and metal complexes for potential future photocatalytic applications. The synthesis focuses on a new rhodamine B derivate and a Pt(II) terpyridine complex, which both contain a polymerizable methacrylate moiety and an acid labile acylhydrazone group. The methacrylate moieties are afterward utilized to synthesize functional model hydrogels mainly consisting of poly(ethylene glycol) methacrylate units. The pH-dependent and temperature-dependent behavior of the hydrogels is investigated by means of Raman and IR spectroscopy assisted by density functional theory calculations and two-dimensional correlation spectroscopy. The spectroscopic results reveal that the Pt(II) terpyridine complex can be released from the polymer matrix by cleaving the C═N bond in an acid environment. The same behavior could not be observed in the case of the rhodamine B dye although it features a comparable C═N bond. The temperature-dependent study shows that the water evaporation has a significant influence neither on the molecular structure of the hydrogel nor on the model photocatalytic moieties.

  20. An investigation of cerebrograph imaging system

    International Nuclear Information System (INIS)

    Chen Lianxiang; Zhang Qingling; Wang Xinhui; Luo Qikun

    1994-01-01

    A cerebrograph imaging system was investigated for the diagnosis of cerebrovascular diseases. This system can quantitatively analyse and map the regional cerebral blood flow (rCBF) and also the electroencephalography (EEG). The mapping of cerebellum-brain stem area was also realized. This system is the first one to combine the technology of nuclear medicine with electrophysiology, and thereby provide a combined information about the rCBF and the function of brain with coloured rCBF mapping, topographical EEG mapping and quantitative data at the same time. It has important value for the early diagnosis of brain diseases, especially for the cerebral vascular accident

  1. Investigations of medium sized solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2006-01-01

    A large variety of solar combi systems are on the market, but it is still too early to draw conclusions on optimum design of solar combi systems. Among others, the following questions need to be answered: Is an external domestic hot water preparation more desirable than an internal? What...... is the advantage by using inlet stratifiers? To answer the questions, theoretical investigations are carried out for differently designed solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32 Advanced storage concepts...

  2. Integrating incident investigation into the management system

    International Nuclear Information System (INIS)

    Peterson, E.E.

    1992-01-01

    In the last 10 yr, the size and frequency of incidents affecting the communities and environment surrounding chemical processing facilities has increased. The chemical process industry, which has always concerned itself with the safety of its facilities, has responded by committing to stricter standards of operation and management. A critical element of these management practices is the use of a structured incident investigation program. Many facilities have implemented and disciplined themselves to perform good investigation of incidents. However, most of these facilities maintain incident investigation as part of their safety management programs. This allows the process to be disconnected from the management system that deals with the day-to-day business of the facility. The first step of integration is understanding the objectives and functions of the management system into which the integration is to occur. To begin, a common definition of management is needed. Management, for the purposes of this discussion, is defined as the system of activities used to control, coordinate, and improve the flow of work within a facility or organization. This definition refers to several concepts that need further development in order to understand how incident investigation can be integrated into a management system, including (a) flow of work, (b) control, and (c) improvement. Application can be made to the nuclear industry

  3. RSMASS system model development

    International Nuclear Information System (INIS)

    Marshall, A.C.; Gallup, D.R.

    1998-01-01

    RSMASS system mass models have been used for more than a decade to make rapid estimates of space reactor power system masses. This paper reviews the evolution of the RSMASS models and summarizes present capabilities. RSMASS has evolved from a simple model used to make rough estimates of space reactor and shield masses to a versatile space reactor power system model. RSMASS uses unique reactor and shield models that permit rapid mass optimization calculations for a variety of space reactor power and propulsion systems. The RSMASS-D upgrade of the original model includes algorithms for the balance of the power system, a number of reactor and shield modeling improvements, and an automatic mass optimization scheme. The RSMASS-D suite of codes cover a very broad range of reactor and power conversion system options as well as propulsion and bimodal reactor systems. Reactor choices include in-core and ex-core thermionic reactors, liquid metal cooled reactors, particle bed reactors, and prismatic configuration reactors. Power conversion options include thermoelectric, thermionic, Stirling, Brayton, and Rankine approaches. Program output includes all major component masses and dimensions, efficiencies, and a description of the design parameters for a mass optimized system. In the past, RSMASS has been used as an aid to identify and select promising concepts for space power applications. The RSMASS modeling approach has been demonstrated to be a valuable tool for guiding optimization of the power system design; consequently, the model is useful during system design and development as well as during the selection process. An improved in-core thermionic reactor system model RSMASS-T is now under development. The current development of the RSMASS-T code represents the next evolutionary stage of the RSMASS models. RSMASS-T includes many modeling improvements and is planned to be more user-friendly. RSMASS-T will be released as a fully documented, certified code at the end of

  4. Numerical Investigation on the Heat Extraction Capacity of Dual Horizontal Wells in Enhanced Geothermal Systems Based on the 3-D THM Model

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2018-01-01

    Full Text Available The Enhanced Geothermal System (EGS constructs an artificial thermal reservoir by hydraulic fracturing to extract heat economically from hot dry rock. As the core element of the EGS heat recovery process, mass and heat transfer of working fluid mainly occurs in fractures. Since the direction of the natural and induced fractures are generally perpendicular to the minimum principal stress in the formation, as an effective stimulation approach, horizontal well production could increase the contact area with the thermal reservoir significantly. In this paper, the thermal reservoir is developed by a dual horizontal well system and treated as a fractured porous medium composed of matrix rock and discrete fracture network. Using the local thermal non-equilibrium theory, a coupled THM mathematical model and an ideal 3D numerical model are established for the EGS heat extraction process. EGS heat extraction capacity is evaluated in the light of thermal recovery lifespan, average outlet temperature, heat production, electricity generation, energy efficiency and thermal recovery rate. The results show that with certain reservoir and production parameters, the heat production, electricity generation and thermal recovery lifespan can achieve the commercial goal of the dual horizontal well system, but the energy efficiency and overall thermal recovery rate are still at low levels. At last, this paper puts forward a series of optimizations to improve the heat extraction capacity, including production conditions and thermal reservoir construction design.

  5. Development, investigation and modelling of a micro reformer as part of a system for off-grid power supply with PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rochlitz, Lisbeth

    2008-11-18

    In this thesis a micro reformer fuel cell system ({mu}RFCS) for 300 Wel off-grid power supply, fuelled with bioethanol, was simulated, designed, developed and investigated in a test-rig. First a literature study was carried through to point out the specific characteristics of micro reforming, the most important being heat transfer, and present the systems currently under research and already on the market. As a next step, the processes of the RFCS were simulated with the commercial simulation tool CHEMCAD. This comprised thermodynamic equilibrium simulations for the separate reactions of steam reforming, water gas shift and selective methanation. It also included a simulation of the complete {mu}RFCS with thermodynamic equilibrium for all reactors and assumed values for heat loss and fuel cell efficiency. The resulting net electrical efficiency was 24%. As a third step, a reaction pathway scheme with parallel and serial reactions for the steam reforming reaction of ethanol was simulated, developed, evaluated and proven plausible by matching the simulation to experimental results obtained in the {mu}RFCS test rig. The equilibrium simulations were used to evaluate the catalyst screening carried through for reformer, water gas shift and selective methanation catalysts. The catalysts for the {mu}RFCS were chosen and the optimum operating conditions determined by the screening tests. Having accomplished the simulation and design of the system, the largest proportion of this work was spent on the construction, set-up, testing and evaluation of the complete {mu}RFCS. The focus for the evaluations lay on the reformer side of the system. The technical feasibility was demonstrated for an ethanol/water mix of 3 ml/min at S/C 3. The first tests without optimized heat and water management between the reformer system and the fuel cell system resulted in power output of around 115 W{sub el}, at a total electrical efficiency of 31%. (orig.)

  6. Investigation and Modeling of Cranberry Weather Stress.

    Science.gov (United States)

    Croft, Paul Joseph

    Cranberry bog weather conditions and weather-related stress were investigated for development of crop yield prediction models and models to predict daily weather conditions in the bog. Field investigations and data gathering were completed at the Rutgers University Blueberry/Cranberry Research Center experimental bogs in Chatsworth, New Jersey. Study indicated that although cranberries generally exhibit little or no stomatal response to changing atmospheric conditions, the evaluation of weather-related stress could be accomplished via use of micrometeorological data. Definition of weather -related stress was made by establishing critical thresholds of the frequencies of occurrence, and magnitudes of, temperature and precipitation in the bog based on values determined by a review of the literature and a grower questionnaire. Stress frequencies were correlated with cranberry yield to develop predictive models based on the previous season's yield, prior season data, prior and current season data, current season data; and prior and current season data through July 31 of the current season. The predictive ability of the prior season models was best and could be used in crop planning and production. Further examination of bog micrometeorological data permitted the isolation of those weather conditions conducive to cranberry scald and allowed for the institution of a pilot scald advisory program during the 1991 season. The micrometeorological data from the bog was also used to develop models to predict daily canopy temperature and precipitation, based on upper air data, for grower use. Models were developed for each month for maximum and minimum temperatures and for precipitation and generally performed well. The modeling of bog weather conditions is an important first step toward daily prediction of cranberry weather-related stress.

  7. Systemic resilience model

    International Nuclear Information System (INIS)

    Lundberg, Jonas; Johansson, Björn JE

    2015-01-01

    It has been realized that resilience as a concept involves several contradictory definitions, both for instance resilience as agile adjustment and as robust resistance to situations. Our analysis of resilience concepts and models suggest that beyond simplistic definitions, it is possible to draw up a systemic resilience model (SyRes) that maintains these opposing characteristics without contradiction. We outline six functions in a systemic model, drawing primarily on resilience engineering, and disaster response: anticipation, monitoring, response, recovery, learning, and self-monitoring. The model consists of four areas: Event-based constraints, Functional Dependencies, Adaptive Capacity and Strategy. The paper describes dependencies between constraints, functions and strategies. We argue that models such as SyRes should be useful both for envisioning new resilience methods and metrics, as well as for engineering and evaluating resilient systems. - Highlights: • The SyRes model resolves contradictions between previous resilience definitions. • SyRes is a core model for envisioning and evaluating resilience metrics and models. • SyRes describes six functions in a systemic model. • They are anticipation, monitoring, response, recovery, learning, self-monitoring. • The model describes dependencies between constraints, functions and strategies

  8. Digital Forensic Investigation Models, an Evolution study

    Directory of Open Access Journals (Sweden)

    Khuram Mushtaque

    2015-10-01

    Full Text Available In business today, one of the most important segments that enable any business to get competitive advantage over others is appropriate, effective adaptation of Information Technology into business and then managing and governing it on their will. To govern IT organizations need to identify value of acquiring services of forensic firms to compete cyber criminals. Digital forensic firms follow different mechanisms to perform investigation. Time by time forensic firms are facilitated with different models for investigation containing phases for different purposes of the entire process. Along with forensic firms, enterprises also need to build a secure and supportive platform to make successful investigation process possible. We have underlined different elements of organizations in Pakistan; need to be addressed to provide support to forensic firms.

  9. Selected System Models

    Science.gov (United States)

    Schmidt-Eisenlohr, F.; Puñal, O.; Klagges, K.; Kirsche, M.

    Apart from the general issue of modeling the channel, the PHY and the MAC of wireless networks, there are specific modeling assumptions that are considered for different systems. In this chapter we consider three specific wireless standards and highlight modeling options for them. These are IEEE 802.11 (as example for wireless local area networks), IEEE 802.16 (as example for wireless metropolitan networks) and IEEE 802.15 (as example for body area networks). Each section on these three systems discusses also at the end a set of model implementations that are available today.

  10. Investigation related to multispectral imaging systems

    Science.gov (United States)

    Nalepka, R. F.; Erickson, J. D.

    1974-01-01

    A summary of technical progress made during a five year research program directed toward the development of operational information systems based on multispectral sensing and the use of these systems in earth-resource survey applications is presented. Efforts were undertaken during this program to: (1) improve the basic understanding of the many facets of multispectral remote sensing, (2) develop methods for improving the accuracy of information generated by remote sensing systems, (3) improve the efficiency of data processing and information extraction techniques to enhance the cost-effectiveness of remote sensing systems, (4) investigate additional problems having potential remote sensing solutions, and (5) apply the existing and developing technology for specific users and document and transfer that technology to the remote sensing community.

  11. An ion-neutral model to investigate chemical ionization mass spectrometry analysis of atmospheric molecules - application to a mixed reagent ion system for hydroperoxides and organic acids

    Science.gov (United States)

    Heikes, Brian G.; Treadaway, Victoria; McNeill, Ashley S.; Silwal, Indira K. C.; O'Sullivan, Daniel W.

    2018-04-01

    An ion-neutral chemical kinetic model is described and used to simulate the negative ion chemistry occurring within a mixed-reagent ion chemical ionization mass spectrometer (CIMS). The model objective was the establishment of a theoretical basis to understand ambient pressure (variable sample flow and reagent ion carrier gas flow rates), water vapor, ozone and oxides of nitrogen effects on ion cluster sensitivities for hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HFo) and acetic acid (HAc). The model development started with established atmospheric ion chemistry mechanisms, thermodynamic data and reaction rate coefficients. The chemical mechanism was augmented with additional reactions and their reaction rate coefficients specific to the analytes. Some existing reaction rate coefficients were modified to enable the model to match laboratory and field campaign determinations of ion cluster sensitivities as functions of CIMS sample flow rate and ambient humidity. Relative trends in predicted and observed sensitivities are compared as instrument specific factors preclude a direct calculation of instrument sensitivity as a function of sample pressure and humidity. Predicted sensitivity trends and experimental sensitivity trends suggested the model captured the reagent ion and cluster chemistry and reproduced trends in ion cluster sensitivity with sample flow and humidity observed with a CIMS instrument developed for atmospheric peroxide measurements (PCIMSs). The model was further used to investigate the potential for isobaric compounds as interferences in the measurement of the above species. For ambient O3 mixing ratios more than 50 times those of H2O2, O3-(H2O) was predicted to be a significant isobaric interference to the measurement of H2O2 using O2-(H2O2) at m/z 66. O3 and NO give rise to species and cluster ions, CO3-(H2O) and NO3-(H2O), respectively, which interfere in the measurement of CH3OOH using O2-(CH3OOH) at m/z 80. The CO3-(H2O

  12. Modular robotic system for forensic investigation support

    Science.gov (United States)

    Kowalski, Grzegorz; Główka, Jakub; Maciaś, Mateusz; Puchalski, Sławomir

    2017-10-01

    Forensic investigation on the crime scene is an activity that requires not only knowledge about the ways of searching for evidence, collecting and processing them. In some cases the area of operation might not be properly secured and poses threat to human health or life. Some devices or materials may be left intentionally or not to injure potential investigators. Besides conventional explosives, threats can be in form of CBRN materials, which have not only immediate effect on the exposed personnel, but can contaminate further people, when being transferred for example on clothes or unsecured equipment. In this case a risk evaluation should be performed, that can lead to conclusions that it is too dangerous for investigators to work. In that kind of situation remote devices, which are able to examine the crime scene and secure samples, can be used. In the course of R&D activities PIAP developed a system, which is based on small UGV capable of carrying out inspection of suspicious places and securing evidence, when needed. The system consists of remotely controlled mobile robot, its control console and a set of various inspection and support tools, that enable detection of CBRN threats as well as revelation, documentation and securing of the evidence. This paper will present main features of the system, like mission adjustment possibilities and communication aspects, and also examples of the forensic accessories.

  13. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  14. Tethered Satellite System Contingency Investigation Board

    Science.gov (United States)

    1992-11-01

    The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether

  15. Numerical Modeling of Microelectrochemical Systems

    DEFF Research Database (Denmark)

    Adesokan, Bolaji James

    for the reactants in the bulk electrolyte that are traveling waves. The first paper presents the mathematical model which describes an electrochemical system and simulates an electroanalytical technique called cyclic voltammetry. The model is governed by a system of advection–diffusion equations with a nonlinear...... reaction term at the boundary. We investigate the effect of flow rates, scan rates, and concentration on the cyclic voltammetry. We establish that high flow rates lead to the reduced hysteresis in the cyclic voltammetry curves and increasing scan rates lead to more pronounced current peaks. The final part...... of the paper shows that the response current in a cyclic voltammetry increases proportionally to the electrolyte concentration. In the second paper we present an experiment of an electrochemical system in a microfluidc system and compare the result to the numerical solutions. We investigate how the position...

  16. The use of zebrafish as a model system for investigating the role of the SULTs in the metabolism of endogenous compounds and xenobiotics.

    Science.gov (United States)

    Kurogi, Katsuhisa; Liu, Tzu-An; Sakakibara, Yoichi; Suiko, Masahito; Liu, Ming-Cheh

    2013-11-01

    In recent years, zebrafish has emerged as a useful animal model for biomedical research. The deciphering of the zebrafish genome has revealed that many of the enzymes involved in the metabolism of endogenous compounds and xenobiotics are conserved between zebrafish and humans. This review summarizes the information currently available concerning the zebrafish cytosolic sulfotransferases (SULTs), a group of phase II enzymes that have been proposed to be involved in the regulation and homeostasis of key endogenous compounds and the detoxification of xenobiotics. To date, 20 zebrafish SULTs that fall into six major SULT gene families have been identified. Of the 20 SULTs 18 have been cloned, expressed, purified and characterized. These zebrafish SULTs were shown to exhibit differential substrate specificities for endogenous compounds such as monoamine transmitters, steroid/thyroid hormones and bile salts, as well as xenobiotics including environmental toxicants and drugs. These findings provide a foundation for using zebrafish as a model for investigating further the physiological, pharmacological, and toxicological involvement of the SULTs.

  17. Modelling of wastewater systems

    DEFF Research Database (Denmark)

    Bechmann, Henrik

    Oxygen Demand) flux and SS flux in the inlet to the WWTP. COD is measured by means of a UV absorption sensor while SS is measured by a turbidity sensor. These models include a description of the deposit of COD and SS amounts, respectively, in the sewer system, and the models can thus be used to quantify......In this thesis, models of pollution fluxes in the inlet to 2 Danish wastewater treatment plants (WWTPs) as well as of suspended solids (SS) concentrations in the aeration tanks of an alternating WWTP and in the effluent from the aeration tanks are developed. The latter model is furthermore used...... to analyze and quantify the effect of the Aeration Tank Settling (ATS) operating mode, which is used during rain events. Furthermore, the model is used to propose a control algorithm for the phase lengths during ATS operation. The models are mainly formulated as state space model in continuous time...

  18. The investigation of tethered satellite system dynamics

    Science.gov (United States)

    Lorenzini, E. C.

    1986-01-01

    The analysis of the rotational dynamics of the satellite was focused on the rotational amplitude increase of the satellite, with respect to the tether, during retrieval. The dependence of the rotational amplitude upon the tether tension variation to the power 1/4 was thoroughly investigated. The damping of rotational oscillations achievable by reel control was also quantified while an alternative solution that makes use of a lever arm attached with a universal joint to the satellite was proposed. Comparison simulations between the Smithsonian Astrophysical Observatory and the Martin Marietta (MMA) computer code of reteival maneuvers were also carried out. The agreement between the two, completely independent, codes was extremely close, demonstrating the reliability of the models. The slack tether dynamics during reel jams was analytically investigated in order to identify the limits of applicability of the SLACK3 computer code to this particular case. Test runs with SLACK3 were also carried out.

  19. Book Review: System Forensics, Investigation, and Response

    Directory of Open Access Journals (Sweden)

    Nate Keith

    2012-06-01

    Full Text Available Vacca, J. R. and Rudolph, K. (2011. System Forensics, Investigation, and Response. Sudbury, MA: Jones and Bartlett Learning. 339 + xv pages, ISBN: 978-0-7637-9134-6, US$89.95.Reviewed by Nate Keith, MBA, (natejkeith@gmail.comI recently expressed an interest to a respected colleague in finding a way to “give back” to the forensic community. He suggested writing a review for a text he recently received and provide feedback to the community. It is my intent to present an objective analysis of System Forensics, Investigation, and Response.Written by John R. Vacca and K Rudolph, this book is part of the Jones and Bartlett Learning Information Systems Security & Assurance Series.  Both Vacca and Rudolph have considerable experience in the information technology field as is demonstrated by the back cover notes: “John R. Vacca is an information technology consultant and internationally known best-selling author based in Pomeroy, Ohio.  Since 1982, he has written 62 books and more than 600 articles in the areas of advanced storage, computer security, and aerospace technology.(see PDF for full review

  20. Two activities with a simple model of the solar system: discovering Kepler’s 3rd law and investigating apparent motion of Venus

    Science.gov (United States)

    Rovšek, Barbara; Guštin, Andrej

    2018-01-01

    An astronomy ‘experiment’ composed of three parts is described in the article. Being given necessary data a simple model of inner planets of the solar system is made in the first part with planets’ circular orbits using appropriate scale. In the second part revolution of the figurines used as model representations of the planets along their orbits is observed. In the third part of activity apparent motion of Venus with respect to the observer on the Earth is studied. In the second part of the paper problems are given, which relate to experimental activities and are designed to test if learning outcomes of the experiment have been achieved: if correlation between orbital radius and orbital velocity has been perceived, concepts related to motion of Venus as observed from the Earth have been acquired and periodicity recognized. Described astronomy ‘experiment’ was one of the three science experiments given to 11 and 12 years old students prior to Slovene science competition in 2017 (the call for competition is at www.dmfa.si, guidelines for the experiment (in Slovene) can be found at www.kresnickadmfa.si/files/2016/07/poskus_1617_r67p1_S.pdf). At the end of the paper the results obtained at competition are presented.

  1. Preliminary Earth System Modeling (cGENIE) of Paired Organic and Inorganic Carbon Isotope Records to Investigate Carbon Cycle Behavior During the Triassic-Jurassic Transition

    Science.gov (United States)

    Yager, J. A.; Stellmann, J. L.; West, A. J.; Corsetti, F. A.; Berelson, W.; Bottjer, D. J.; Rosas, S.

    2016-12-01

    The stable C isotope composition of marine carbonate and organic C yields information regarding major changes in global carbon cycling over geologic time. Excursions from baseline C isotope compositions during the Late Triassic and early Jurassic coincide with the end-Triassic mass extinction. Much remains to be understood about the global extent of these excursions, and about their causes. Here, we use observations from a record from Northern Peru (Levanto) to generate hypotheses concerning C cycle changes, focusing on comparison to other sections spanning the Triassic-Jurassic boundary. Our observations include a decoupling between organic and inorganic C isotopes in some records, broad similarities in the pattern of excursions between sections, and a potential offset between the major ocean basins (Tethys and Panthalassa) in both inorganic and organic C isotope records. We are currently adapting a spatially resolved Earth System Model (cGENIE) for this time period with the goal of using this model to explore possible mechanistic causes of these observations, aiming to tie the C isotope records to changes in global carbon cycle dynamics at the time.

  2. 4D stress evolution models of the San Andreas Fault System: Investigating time- and depth-dependent stress thresholds over multiple earthquake cycles

    Science.gov (United States)

    Burkhard, L. M.; Smith-Konter, B. R.

    2017-12-01

    4D simulations of stress evolution provide a rare insight into earthquake cycle crustal stress variations at seismogenic depths where earthquake ruptures nucleate. Paleoseismic estimates of earthquake offset and chronology, spanning multiple earthquakes cycles, are available for many well-studied segments of the San Andreas Fault System (SAFS). Here we construct new 4D earthquake cycle time-series simulations to further study the temporally and spatially varying stress threshold conditions of the SAFS throughout the paleoseismic record. Interseismic strain accumulation, co-seismic stress drop, and postseismic viscoelastic relaxation processes are evaluated as a function of variable slip and locking depths along 42 major fault segments. Paleoseismic earthquake rupture histories provide a slip chronology dating back over 1000 years. Using GAGE Facility GPS and new Sentinel-1A InSAR data, we tune model locking depths and slip rates to compute the 4D stress accumulation within the seismogenic crust. Revised estimates of stress accumulation rate are most significant along the Imperial (2.8 MPa/100yr) and Coachella (1.2 MPa/100yr) faults, with a maximum change in stress rate along some segments of 11-17% in comparison with our previous estimates. Revised estimates of earthquake cycle stress accumulation are most significant along the Imperial (2.25 MPa), Coachella (2.9 MPa), and Carrizo (3.2 MPa) segments, with a 15-29% decrease in stress due to locking depth and slip rate updates, and also postseismic relaxation from the El Mayor-Cucapah earthquake. Because stress drops of major strike-slip earthquakes rarely exceed 10 MPa, these models may provide a lower bound on estimates of stress evolution throughout the historical era, and perhaps an upper bound on the expected recurrence interval of a particular fault segment. Furthermore, time-series stress models reveal temporally varying stress concentrations at 5-10 km depths, due to the interaction of neighboring fault

  3. Preface: the hydra model system.

    Science.gov (United States)

    Galliot, Brigitte

    2012-01-01

    The freshwater Hydra polyp emerged as a model system in 1741 when Abraham Trembley not only discovered its amazing regenerative potential, but also demonstrated that experimental manipulations pave the way to research in biology. Since then, Hydra flourished as a potent and fruitful model system to help answer questions linked to cell and developmental biology, as such as the setting up of an organizer to regenerate a complex missing structure, the establishment and maintainance of polarity in a multicellular organism, the development of mathematical models to explain the robust developmental rules observed in this animal, the maintainance of stemness and multipotency in a highly dynamic environment, the plasticity of differentiated cells, to name but a few. However the Hydra model system is not restricted to cell and developmental biology; during the past 270 years it has also been heavily used to investigate the relationships between Hydra and its environment, opening new horizons concerning neurophysiology, innate immunity, ecosystems, ecotoxicology, symbiosis...

  4. Investigation of Kinetics of MOCVD Systems

    Science.gov (United States)

    1991-12-01

    the water bubbler was confirmed by mass spectometry to contain only carrier gas H2. After each experiment the group III chloride condensate in the cold...AariUMw VA Z-430Z wi to te Ofle d Me gmwwt - d Buig. Pepnwwk Recdim P (070641 U. W80 DC 2=. 1. AGENCY USE ONLY (Leave BIan4 2 REPORT DATE a REPORT...TYPE AND DATES COVERED December 1991 Final 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS INVESTIGATION OF KINETICS OF MOCVD SYSTEMS C - F19628-86-K-0012 PE

  5. Characterization of Caco-2 cells stably expressing the protein-based zinc probe eCalwy-5 as a model system for investigating intestinal zinc transport.

    Science.gov (United States)

    Maares, Maria; Keil, Claudia; Thomsen, Susanne; Günzel, Dorothee; Wiesner, Burkhard; Haase, Hajo

    2018-01-29

    Intestinal zinc resorption, in particular its regulation and mechanisms, are not yet fully understood. Suitable intestinal cell models are needed to investigate zinc uptake kinetics and the role of labile zinc in enterocytes in vitro. Therefore, a Caco-2 cell clone was produced, stably expressing the genetically encoded zinc biosensor eCalwy-5. The aim of the present study was to reassure the presence of characteristic enterocyte-specific properties in the Caco-2-eCalwy clone. Comparison of Caco-2-WT and Caco-2-eCalwy cells revealed only slight differences regarding subcellular localization of the tight junction protein occludin and alkaline phosphatase activity, which did not affect basic integrity of the intestinal barrier or the characteristic brush border membrane morphology. Furthermore, introduction of the additional zinc-binding protein in Caco-2 cells did not alter mRNA expression of the major intestinal zinc transporters (zip4, zip5, znt-1 and znt-5), but increased metallothionein 1a-expression and cellular resistance to higher zinc concentrations. Moreover, this study examines the effect of sensor expression level on its saturation with zinc. Fluorescence cell imaging indicated considerable intercellular heterogeneity in biosensor-expression. However, FRET-measurements confirmed that these differences in expression levels have no effect on fractional zinc-saturation of the probe. Copyright © 2018 Elsevier GmbH. All rights reserved.

  6. Modeling Complex Systems

    CERN Document Server

    Boccara, Nino

    2010-01-01

    Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).

  7. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  8. Predicting Geotechnical Investigation Using the Knowledge Based System

    Directory of Open Access Journals (Sweden)

    Bojan Žlender

    2016-01-01

    Full Text Available The purpose of this paper is to evaluate the optimal number of investigation points and each field test and laboratory test for a proper description of a building site. These optimal numbers are defined based on their minimum and maximum number and with the equivalent investigation ratio. The total increments of minimum and maximum number of investigation points for different building site conditions were determined. To facilitate the decision-making process for a number of investigation points, an Adaptive Network Fuzzy Inference System (ANFIS was proposed. The obtained fuzzy inference system considers the influence of several entry parameters and computes the equivalent investigation ratio. The developed model (ANFIS-SI can be applied to characterize any building site. The ANFIS-SI model takes into account project factors which are evaluated with a rating from 1 to 10. The model ANFIS-SI, with integrated recommendations can be used as a systematic decision support tool for engineers to evaluate the number of investigation points, field tests, and laboratory tests for a proper description of a building site. The determination of the optimal number of investigative points and the optimal number of each field test and laboratory test is presented on reference case.

  9. Investigations of Intelligent Solar Heating Systems for Single Family House

    DEFF Research Database (Denmark)

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

    2014-01-01

    Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...... is a tank in tank heat storage with domestic hot water in the inner tank and space heating water in the outer tank. The total tank volume is 750 liters and the solar collector area is 9 m2. The auxiliary energy supply system is based on electrical heating element(s)/heat pump and is different for all three...... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys...

  10. Artificial membranes as models in penetration investigations.

    Science.gov (United States)

    Krulikowska, M; Arct, J; Lucova, M; Cetner, B; Majewski, S

    2013-02-01

    In vitro methods used in the research of transepidermal transport of active substances generally rely on the penetration rate of test compounds through standard membranes. Models typically used in penetration experiments are specially prepared human or animal skin samples or synthetic membranes. The objective of this study was to establish if the test results for an artificial liposome membrane can be extrapolated to determine the actual bioavailability of active substances. Tests were conducted in a side-by-side diffusion cell. As model membranes, a liquid-crystal lipid membrane (LM), phospholipid membrane (PM) and pig skin sample were used. The test compounds were eight synthetic dyes used in hair colouring products. Research findings reveal that membranes composed of lipids, identical to those present in the epidermis and forming analogical liquid-crystal structures provide a close approximation of the actual bioavailability of active substances (correlation between the results obtained for pig skin and LM was significant: R = 0.95 and R = 0.93 in the presence of a 1% Sodium dodecyl sulphate in donor system). Unlike biological membranes, intercellular cement does not contain phospholipids. The observed correlation between penetration coefficients through the PM and pig skin was not significant (R = 0.82). The experiments confirm that the PM constitutes a less credible model for the studies of transepidermal transport in real life conditions. © 2012 John Wiley & Sons A/S.

  11. On-line system for investigation of atomic structure

    International Nuclear Information System (INIS)

    Amus'ya, M.Ya.; Chernysheva, L.V.

    1983-01-01

    A description of the on-line ATOM system is presented that enables to investigate the structure of atomic electron shells and their interactions with different scattering particles-electrons, positronse photons, mesons - with the use of computerized numerical solutions. The problem is stated along with mathematical description of atomic properties including theoretical and numerical models for each investigated physical process. The ATOM system structure is considered. The Hartree-Fock method is used to determine the wave functions of the ground and excited atomic states. The programs are written in the ALGOL langauge. Different atomic characteristics were possible to be calculated for the first time with an accuracy exceeding an experimental one

  12. Investigation of the interactions between wind turbines and radio systems aimed at establishing co-siting guidelines. Phase 1: Introduction and modelling of wind turbine scatter, appendices E, F and G

    International Nuclear Information System (INIS)

    Dabis, H.S.; Chignell, R.J.

    1997-01-01

    The potential for wind turbines to interfere with radio systems can be a source of conflict between radio operators and the wind energy community. In this report, the problem of accurately predicting the effects of wind turbines on radio systems with the aim of establishing guidelines for their installation is investigated. Initially models for the scatter mechanisms that occur at the wind turbine are developed. These models predict the wind turbine radar cross section and the modulation effects due to the rotation of the blades. Initial validation of these models is established by comparing the predicted results with a set of measurements obtained from experiments performed on a 20:1 scale model wind turbine. It is shown that generally these results agree well. These results are then used in the guideline formulation to compute, for specific radio systems, regions where wind turbines cannot be installed. Examples using realistic parameters for various radio systems are presented. Further validation of the derived models is required. (author)

  13. Investigation and Modeling of Capacitive Human Body Communication.

    Science.gov (United States)

    Zhu, Xiao-Qi; Guo, Yong-Xin; Wu, Wen

    2017-04-01

    This paper presents a systematic investigation of the capacitive human body communication (HBC). The measurement of HBC channels is performed using a novel battery-powered system to eliminate the effects of baluns, cables and instruments. To verify the measured results, a numerical model incorporating the entire HBC system is established. Besides, it is demonstrated that both the impedance and path gain bandwidths of HBC channels is affected by the electrode configuration. Based on the analysis of the simulated electric field distribution, an equivalent circuit model is proposed and the circuit parameters are extracted using the finite element method. The transmission capability along the human body is also studied. The simulated results using the numerical and circuit models coincide very well with the measurement, which demonstrates that the proposed circuit model can effectively interpret the operation mechanism of the capacitive HBC.

  14. Computational models of complex systems

    CERN Document Server

    Dabbaghian, Vahid

    2014-01-01

    Computational and mathematical models provide us with the opportunities to investigate the complexities of real world problems. They allow us to apply our best analytical methods to define problems in a clearly mathematical manner and exhaustively test our solutions before committing expensive resources. This is made possible by assuming parameter(s) in a bounded environment, allowing for controllable experimentation, not always possible in live scenarios. For example, simulation of computational models allows the testing of theories in a manner that is both fundamentally deductive and experimental in nature. The main ingredients for such research ideas come from multiple disciplines and the importance of interdisciplinary research is well recognized by the scientific community. This book provides a window to the novel endeavours of the research communities to present their works by highlighting the value of computational modelling as a research tool when investigating complex systems. We hope that the reader...

  15. Investigation of Microgranular Adsorptive Filtration System

    Science.gov (United States)

    Cai, Zhenxiao

    Over the past few decades, enormous advances have been made in the application of low-pressure membrane filtration to both drinking water and wastewater treatment. Nevertheless, the full potential of this technology has not been reached, due primarily to limitations imposed by membrane fouling. In drinking water treatment, much of the fouling is caused by soluble and particulate natural organic matter (NOM). Efforts to overcome the problem have focused on removal of NOM from the feed solution, usually by addition of conventional coagulants like alum and ferric chloride (FeCl3) or adsorbents like powdered activated carbon (PAC). While coagulants and adsorbents can remove a portion of the NOM, their performance with respect to fouling control has been inconsistent, often reducing fouling but sometimes having no effect or even exacerbating fouling. This research investigated microgranular adsorptive filtration (muGAF), a process that combines three existing technologies---granular media filtration, packed bed adsorption, and membrane filtration---in a novel way to reduce membrane fouling while simultaneously removing NOM from water. In this technology, a thin layer of micron-sized adsorbent particles is deposited on the membrane prior to delivering the feed to the system. The research reported here represents the first systematic study of muGAF, and the results demonstrate the promising potential of this process. A new, aluminum-oxide-based adsorbent---heated aluminum oxide particles (HAOPs)---was synthesized and shown to be very effective for NOM removal as well as fouling reduction in muGAF systems. muGAF has also been demonstrated to work well with powdered activated carbon (PAC) as the adsorbent, but not as well as when HAOPs are used; the process has also been successful when used with several different membrane types and configurations. Experiments using a wide range of operational parameters and several analytical tools lead to the conclusion that the fouling

  16. Information Systems Efficiency Model

    Directory of Open Access Journals (Sweden)

    Milos Koch

    2017-07-01

    Full Text Available This contribution discusses the basic concept of creating a new model for the efficiency and effectiveness assessment of company information systems. The present trends in this field are taken into account, and the attributes are retained of measuring the optimal solutions for a company’s ICT (the implementation, functionality, service, innovations, safety, relationships, costs, etc.. The proposal of a new model of assessment comes from our experience with formerly implemented and employed methods, methods which we have modified in time and adapted to companies’ needs but also to the necessaries of our research that has been done through the ZEFIS portal. The most noteworthy of them is the HOS method that we have discussed in a number of forums. Its main feature is the fact that it respects the complexity of an information system in correlation with the balanced state of its individual parts.

  17. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    In this paper an investigation of floor heating systems is performed with respect to heating demand and room temperature. Presently (2001) no commercially available building simulation programs that can be used to evaluate heating demand and thermal comfort in buildings with building integrated....... The model calculates heating demand, room temperatures, and thermal comfort parameters for a person in the room. The model is based on a numerical Finite Control Volume (FCV) method for the heat transfer in walls, ceiling, windows and floor. The model uses both convective and radiative heat transfer...... to the room air and between the room surfaces. The simulation model has been used to calculate heating demand and room temperature in a typical well insulated Danish single-family house with a heating demand of approximately 6000 kWh per year, for a 130 m² house. Two different types of floor heating systems...

  18. Investigations of inter-system common cause failures

    International Nuclear Information System (INIS)

    Nonclerca, P.; Gallois, M.; Vasseur, D.

    2012-01-01

    Intra-system common-cause failures (CCF) are widely studied and addressed in existing PSA models, but the information and studies that incorporate the potential for inter-system CCF is limited. However, the French Safety Authority has requested that EDF investigate the possibility of common-cause failure across system boundaries for Flamanville 3 (an EPR design). Also, the modeling of inter-system CCF, or the proof that their impact is negligible, would satisfy Capability Category III for one of the requirements in the ASME/ANS PRA standard in the U.S. EDF and EPRI have been working on a method to assess when it is necessary to take into account inter-system CCF in a PSA model between 2008 and 2010. This method is based both on the likelihood of inter-system CCF and on its demonstrated potential impact on CDF (core damage frequency). This method was first applied on pumps in different systems of the 900 MWe series plants. The second application concerned the motor-operated valves across different systems, using the same PSA model. This second application helped us refine the method, which was not optimal when the number of concerned components is very large. Since then, the method has been successfully applied on the pumps and 10 kV breakers of the EPR power plant in Flamanville. This paper describes the method and the results obtained in some of these studies. All studies have shown either that components in different systems, when they were not already part of a common cause failure group in the model, are not susceptible to common causes of failure, or that the potential for inter-system common-cause failure is negligible regarding the overall risk. (authors)

  19. Investigation of solar photovoltaic module power output by various models

    International Nuclear Information System (INIS)

    Jakhrani, A.Q.; Othman, A.K.; Rigit, A.R.H.; Baini, R.

    2012-01-01

    This paper aims to investigate the power output of a solar photovoltaic module by various models and to formulate a suitable model for predicting the performance of solar photovoltaic modules. The model was used to correct the configurations of solar photovoltaic systems for sustainable power supply. Different types of models namely the efficiency, power, fill factor and current-voltage characteristic curve models have been reviewed. It was found that the examined models predicted a 40% yield of the rated power in cloudy weather conditions and up to 80% in clear skies. The models performed well in terms of electrical efficiency in cloudy days if the influence of low irradiance were incorporated. Both analytical and numerical methods were employed in the formulation of improved model which gave +- 2% error when compared with the rated power output of solar photovoltaic module. The proposed model is more practical in terms of number of variables used and acceptable performance in humid atmospheres. Therefore, it could be useful for the estimation of power output of the solar photovoltaic systems in Sarawak region. (author)

  20. The control of climate and base-level change on the stratigraphic architecture of fluvio-deltaic systems, investigated by quantitative analogue modelling

    NARCIS (Netherlands)

    Berg van Saparoea, Aart-Peter van den

    2005-01-01

    River systems play an important role in the filling of sedimentary basins and record the history of external forcing processes, such as climate, tectonics and sea-level change, acting on them. They are potential reservoirs for oil, gas and water, and can host coal and placer mineral deposits.

  1. Investigation of sustainable development potential for Ulubey Aquifer System, Turkey

    Directory of Open Access Journals (Sweden)

    U. Burcu

    2014-09-01

    Full Text Available This study investigates sustainable development potential for Ulubey aquifer system which serves as an important water supply for Usak province (Turkey. In recent years, growing population, accelerating industrial activities and decreasing rainfall, as well as contamination of the surface water resources, made groundwater indispensable to meet the freshwater demands of Usak province. Therefore, a sustainable groundwater development plan has to be set up by determining the sustainable yield of the system, which is the aim of this study. To achieve this goal, a mathematical groundwater flow model is constructed in order to test the alternative development scenarios. Results show that the system preserves equilibrium conditions under present stresses. The future effects of possible increases in stresses are also simulated and based on the dynamic responses of the system to changing stresses; sustainable yield and sustainable pumping rate of the aquifer are determined and compared with the safe yield of the system.

  2. Summary of multi-core hardware and programming model investigations

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Suzanne Marie; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.

    2008-05-01

    This report summarizes our investigations into multi-core processors and programming models for parallel scientific applications. The motivation for this study was to better understand the landscape of multi-core hardware, future trends, and the implications on system software for capability supercomputers. The results of this study are being used as input into the design of a new open-source light-weight kernel operating system being targeted at future capability supercomputers made up of multi-core processors. A goal of this effort is to create an agile system that is able to adapt to and efficiently support whatever multi-core hardware and programming models gain acceptance by the community.

  3. Outer membrane phospholipase A in phospholipid bilayers: a model system for concerted computational and experimental investigations of amino acid side chain partitioning into lipid bilayers.

    Science.gov (United States)

    Fleming, Patrick J; Freites, J Alfredo; Moon, C Preston; Tobias, Douglas J; Fleming, Karen G

    2012-02-01

    Understanding the forces that stabilize membrane proteins in their native states is one of the contemporary challenges of biophysics. To date, estimates of side chain partitioning free energies from water to the lipid environment show disparate values between experimental and computational measures. Resolving the disparities is particularly important for understanding the energetic contributions of polar and charged side chains to membrane protein function because of the roles these residue types play in many cellular functions. In general, computational free energy estimates of charged side chain partitioning into bilayers are much larger than experimental measurements. However, the lack of a protein-based experimental system that uses bilayers against which to vet these computational predictions has traditionally been a significant drawback. Moon & Fleming recently published a novel hydrophobicity scale that was derived experimentally by using a host-guest strategy to measure the side chain energetic perturbation due to mutation in the context of a native membrane protein inserted into a phospholipid bilayer. These values are still approximately an order of magnitude smaller than computational estimates derived from molecular dynamics calculations from several independent groups. Here we address this discrepancy by showing that the free energy differences between experiment and computation become much smaller if the appropriate comparisons are drawn, which suggests that the two fields may in fact be converging. In addition, we present an initial computational characterization of the Moon & Fleming experimental system used for the hydrophobicity scale: OmpLA in DLPC bilayers. The hydrophobicity scale used OmpLA position 210 as the guest site, and our preliminary results demonstrate that this position is buried in the center of the DLPC membrane, validating its usage in the experimental studies. We further showed that the introduction of charged Arg at position 210

  4. Investigation on the influence of the TBP diluents on the primary emulsion stability in model extraction systems: TBP-diluents-water solutions of HNO3

    International Nuclear Information System (INIS)

    Rogoz, F.

    1983-01-01

    In the extraction systems containing little quantities of TBP in carbon tetrachloride (CCl 4 ) and kerosene the stable emulsions are created; for higher concentrations of TBP the emulsion stability decreases and increases again for the highest concentrations of TBP. In the TBP solutions in N-octane and benzene the great influence on the primary emulsion stability is observed only for the high concentrations of TBP. The addition of MBP has considerably less influence on the primary emulsion stability than the addition of DBP has, for all used diluents. (author)

  5. Investigation of the photochemical changes of chlorogenic acids induced by ultraviolet light in model systems and in agricultural practice with Stevia rebaudiana cultivation as an example.

    Science.gov (United States)

    Karaköse, Hande; Jaiswal, Rakesh; Deshpande, Sagar; Kuhnert, Nikolai

    2015-04-08

    Mono- and diacyl chlorogenic acids undergo photochemical trans-cis isomerization under ultraviolet (UV) irradiation. The photochemical equilibrium composition was established for eight selected derivatives. In contrast to all other dicaffeoylquinic acid derivatives, cynarin (1,3-dicaffeoylquinic acid) undergoes a [2 + 2] photochemical cycloaddition reaction, constituting a first example of Schmidt's law in a natural product family. The relevance of photochemical isomerization in agricultural practice was investigated using 120 samples of Stevia rebaudiana leave samples grown under defined cultivation conditions. Ratios of cis to trans chlorogenic acids were determined in leaf samples and correlated with climatic and harvesting conditions. The data indicate a clear correlation between the formation of cis-caffeoyl derivatives and sunshine hours prior to harvesting and illustrate the relevance of UV exposure to plant material affecting its phytochemical composition.

  6. System dynamics modelling of situation awareness

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2015-11-01

    Full Text Available . The feedback loops and delays in the Command and Control system also contribute to the complex dynamic behavior. This paper will build on existing situation awareness models to develop a System Dynamics model to support a qualitative investigation through...

  7. 337Info - Unfair Import Investigations Information System

    Data.gov (United States)

    US International Trade Commission — The 337Info database contains data relating to Section 337 investigations instituted, or otherwise initiated, by the U.S. International Trade Commission on or after...

  8. Simulation Modeling Method and Experimental Investigation on the Uniflow Scavenging System of an Opposed-Piston Folded-Cranktrain Diesel Engine

    Directory of Open Access Journals (Sweden)

    Fukang Ma

    2017-05-01

    Full Text Available The scavenging process for opposed-piston folded-cranktrain (OPFC diesel engines can be described by the time evolution of the in-cylinder and exhaust chamber residual gas rates. The relation curve of in-cylinder and exhaust chamber residual gas rate is called scavenging profile, which is calculated through the changes of in-cylinder and exhaust chamber gas compositions determined by computational fluid dynamics (CFD simulation. The scavenging profile is used to calculate the scavenging process by mono-dimensional (1D simulation. The tracer gas method (TGM is employed to validate the accuracy of the scavenging profile. At the same time, the gas exchange performance under different intake and exhaust state parameters was examined based on the TGM. The results show that the scavenging process from 1D simulation and experiment match well, which means the scavenging model obtained by CFD simulation performs well and validation of its effectiveness by TGM is possible. The difference between intake and exhaust pressure has a significant positive effect on the gas exchange performance and trapped gas mass, but the pressure difference has little effect on the scavenging efficiency and the trapped air mass if the delivery ratio exceeds 1.4.

  9. Experimental investigation and model development for a harmonic drive transmission

    International Nuclear Information System (INIS)

    Preissner, C.; Shu, D.; Royston, T.J.

    2007-01-01

    Harmonic drive transmissions (HDTs) are compact, low-backlash, high-ratio, high-resolution rotary motion transmissions. One application to benefit from these attributes is the revolute joint robot. Engineers at the Advanced Photon Source (APS) are investigating the use of this type of robot for the positioning of an x-ray detector; understanding the properties of the robot components is crucial to modeling positioner behavior. The robot bearing elements had been investigated previously, leaving the transmission as the missing component. While the benefits of HDTs are well known, the disadvantages, including fluctuating dissipation characteristics and nonlinear stiffness, are not understood as well. These characteristics can contribute uncontrolled dynamics to the overall robot performance. A dynamometer has been constructed at the APS to experimentally measure the HDT's response. Empirical torque and position data were recorded for multiple transmission load cases and input conditions. In turn, a computer model of the dynamometer HDT system was constructed to approximate the observed response.

  10. Experimental and modeling investigations of solubility and saturated liquid densities and viscosities for binary systems (methane +, ethane +, and carbon dioxide + 2-propanol)

    International Nuclear Information System (INIS)

    Nourozieh, Hossein; Kariznovi, Mohammad; Abedi, Jalal

    2013-01-01

    Highlights: • Solubilities of CH 4 , C 2 H 6 , and CO 2 in 2-propanol and saturated density and viscosity. • Solubility of C 2 H 6 in 2-propanol is higher than CH 4 and CO 2 . • Dissolution of CO 2 increases liquid density and reduces liquid viscosity. • Liquid density and viscosity reduces with dissolution of CH 4 and C 2 H 6 . • Solubilities and saturated liquid densities were predicted with SRK and PR EOS. -- Abstract: Solubilities of methane, ethane, and carbon dioxide in 2-propanol have been measured at the temperatures (303 and 323) K and at the pressures up to 6 MPa using an in-house designed PVT apparatus. The saturated liquid properties, density and viscosity, were also measured in each experiment. Prior to the phase equilibrium measurements, the density and viscosity of pure 2-propanol were measured at the temperatures (303 and 323) K over the pressure range (0.1 to 10) MPa. The dissolution of carbon dioxide in 2-propanol caused a decline in the viscosity of saturated liquid phase while an increase in the density of gas-expanded liquid was observed. The viscosity-pressure trends for methane- and ethane-saturated liquid viscosities were similar to carbon dioxide, but the saturated liquid densities decreased with the dissolution of methane and ethane in 2-propanol. Solubility increased with pressure and decreased with temperature for all compressed gases (methane, ethane and carbon dioxide). The experimental data were well correlated using Soave–Redlich–Kwong and Peng–Robinson equations of state. The solubilities and saturated liquid densities were well represented with both equations of state, and there is no superior equation of state for the modeling of the phase compositions and saturated liquid densities

  11. Investigating models for associating fluids using spectroscopy

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Michelsen, Michael Locht; Passos, Claudia Pereira

    2005-01-01

    Two equations of state (PC-SAFT and CPA) are used to predict the monomer fraction of pure associating fluids. The models each require five pure-component parameters usually obtained by fitting to experimental liquid density and vapor pressure data. Here we also incorporate monomer fractions...... measured using spectroscopy, resulting in models that better predict the monomer fraction (fraction of molecules not participating in hydrogen bonding), without sacrificing the accuracy of the liquid density and vapor pressure correlations. Thus, it is clear that monomer fraction prediction depends......-site schemes perform about equally for ethanol; for higher alcohols a two-site scheme is preferred. This is in accordance with steric arguments. Some difficulties in the interpretation of spectroscopic data and their comparison with the predictions of association models are illustrated. Apparently anomalous...

  12. Framework to investigate emergence in system engineering

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2011-09-01

    Full Text Available to Fromm [7] this is achieved through the application of established scientific knowledge. Natural sciences such as physics, chemistry and biology use experiments to gather data to validate or prove hypotheses and theories, being the basis... look at how to approach real life and complex problems. 2.2 Complex System Engineering Fromm [7] reiterated that when engineering complex systems, science is used to explain and to understand complexity while engineering attempts to hide...

  13. Studies of Catalytic Model Systems

    DEFF Research Database (Denmark)

    Holse, Christian

    of the Cu/ZnO nanoparticles is highly relevant to industrial methanol synthesis for which the direct interaction of Cu and ZnO nanocrystals synergistically boost the catalytic activity. The dynamical behavior of the nanoparticles under reducing and oxidizing environments were studied by means of ex situ X...... as the nanoparticles are reduced. The Cu/ZnO nanoparticles are tested on a  µ-reactor platform and prove to be active towards methanol synthesis, making it an excellent model system for further investigations into activity depended morphology changes....

  14. Investigating non-Markovian dynamics of quantum open systems

    Science.gov (United States)

    Chen, Yusui

    Quantum open system coupled to a non-Markovian environment has recently attracted widespread interest for its important applications in quantum information processing and quantum dissipative systems. New phenomena induced by the non-Markovian environment have been discovered in variety of research areas ranging from quantum optics, quantum decoherence to condensed matter physics. However, the study of the non-Markovian quantum open system is known a difficult problem due to its technical complexity in deriving the fundamental equation of motion and elusive conceptual issues involving non-equilibrium dynamics for a strong coupled environment. The main purpose of this thesis is to introduce several new techniques of solving the quantum open systems including a systematic approach to dealing with non-Markovian master equations from a generic quantum-state diffusion (QSD) equation. In the first part of this thesis, we briefly introduce the non-Markovian quantum-state diffusion approach, and illustrate some pronounced non-Markovian quantum effects through numerical investigation on a cavity-QED model. Then we extend the non-Markovian QSD theory to an interesting model where the environment has a hierarchical structure, and find out the exact non-Markovian QSD equation of this model system. We observe the generation of quantum entanglement due to the interplay between the non-Markovian environment and the cavity. In the second part, we show an innovative method to obtain the exact non-Markovian master equations for a set of generic quantum open systems based on the corresponding non-Markovian QSD equations. Multiple-qubit systems and multilevel systems are discussed in details as two typical examples. Particularly, we derive the exact master equation for a model consisting of a three-level atom coupled to an optical cavity and controlled by an external laser field. Additionally, we discuss in more general context the mathematical similarity between the multiple

  15. Adaptable data management for systems biology investigations

    Directory of Open Access Journals (Sweden)

    Burdick David

    2009-03-01

    Full Text Available Abstract Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry. We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community.

  16. Adaptable data management for systems biology investigations

    Science.gov (United States)

    Boyle, John; Rovira, Hector; Cavnor, Chris; Burdick, David; Killcoyne, Sarah; Shmulevich, Ilya

    2009-01-01

    Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry). We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community. PMID:19265554

  17. Investigating surety methodologies for cognitive systems.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); Peercy, David Eugene; Mills, Kristy (University of New Mexico, Albuquerque, NM); Caldera, Eva (University of New Mexico, Albuquerque, NM)

    2006-11-01

    Advances in cognitive science provide a foundation for new tools that promise to advance human capabilities with significant positive impacts. As with any new technology breakthrough, associated technical and non-technical risks are involved. Sandia has mitigated both technical and non-technical risks by applying advanced surety methodologies in such areas as nuclear weapons, nuclear reactor safety, nuclear materials transport, and energy systems. In order to apply surety to the development of cognitive systems, we must understand the concepts and principles that characterize the certainty of a system's operation as well as the risk areas of cognitive sciences. This SAND report documents a preliminary spectrum of risks involved with cognitive sciences, and identifies some surety methodologies that can be applied to potentially mitigate such risks. Some potential areas for further study are recommended. In particular, a recommendation is made to develop a cognitive systems epistemology framework for more detailed study of these risk areas and applications of surety methods and techniques.

  18. Investigation of The Omaha System for dentistry.

    Science.gov (United States)

    Jurkovich, M W; Ophaug, M; Salberg, S; Monsen, K

    2014-01-01

    Today, dentists and hygienists have inadequate tools to identify contributing factors to dental disease, diagnosis of disease or to document outcomes in a standardized and machine readable format. Increasing demand to find the most effective care methodologies make the development of further terminologies for dentistry more urgent. Preventive care is the focus of early efforts to define best practices. We reviewed one possibility with a history of public health documentation that might assist in these early efforts at identifying best practices. This paper examines, through a survey of dentists, the Omaha System Problem Classification Scheme. The survey requested that dentists rate the usefulness of knowing about specific signs and symptoms for each of the 42 problems within the Problem list of the Omaha System. Using a weighted scoring system, 22 of the 42 problems received over 50% of the possible maximum score and 30 of the 42 problems received at least 25% of the possible points. These findings suggests that further evaluation of The Omaha System, may be useful to dentistry. At a minimum, the survey provides additional information about non-physiological problems, signs, and symptoms that may be appropriate for documentation purposes within an electronic health record (EHR) used in dentistry.

  19. Calorimetric investigations of U-Bi system

    International Nuclear Information System (INIS)

    Agarwal, Renu; Joshi, A.R.

    2013-01-01

    U 0.333 Bi 0.667 is a compound that may form on breach of clad during reactor operation with metallic fuel and lead-bismuth coolant. Therefore, enthalpy of mixing of U-Bi liquid solution in limited composition range and enthalpy of formation of U 0.333 Bi 0.667 compound were measured by high temperature calorimetry. The enthalpy of mixing follows subregular solution model and enthalpy of formation U 0.333 Bi 0.667 from U(l) and Bi(l) at 843 K was -52.5 kJ/mol and -40.8 kJ/mol from U(s) and Bi(s) at 298.15 K. Both enthalpy of mixing and enthalpy of formation of intermetallic compound obtained experimentally were compared with Miedema model values. (author)

  20. Immune system investigations for radiation workers

    International Nuclear Information System (INIS)

    Obreja, Doina; Tulbure, Rodica; Marinescu, Irina

    2001-01-01

    During the last decade a great deal of attention has been paid to the research in the field of the immune system. Some important steps forward have been achieved in understanding the mechanisms of action and control of the immunologic responses. At the same time the concern for the possible health effects of exposure to ionizing radiation has considerably increased. On the purpose of the evaluation of the modifications induced by the ionizing radiation for radiation workers, we have applied the method of lymphocytic subpopulations, a method that evinces the proportions for the various subtypes of lymphocytes having different roles within the immune system. A number of 62 persons, employees of the Institute of Physics and Nuclear Engineering at Bucharest - Magurele were involved in this study. All radiation workers from 2 departments characterized by a high exposure to ionizing radiation were included, as follows: Group no. 1, consisting of 20 persons working at RWTS (Radioactive Waste Treating Station), thus presenting both external and internal irradiation; Group no. 2, consisting of 18 persons working at RPC (Radioactive Isotopes Preparing Center), a place where besides the radioactive contamination, the chemical risk was also present. The control group (consisting of 24 persons) was formed of employees from the same institute, with the difference that they were not radiation workers. For the statistical processing of the results the programs EPI INFO 6 and CIA were used. Significantly, when analyzing globally the lymphocytic modifications for TT and/or B lymphocytes (either increments or decrements when compared to the normal values), a noticeable statistical difference among the groups in terms of the frequency of the immune system modifications (Hi square test p=0.001) occurs. The results are in accordance to those in special literature mentioning age as a factor having a role in the appearance of the immune modifications. The obtained results indicate a

  1. An investigation of prior knowledge in Automatic Music Transcription systems.

    Science.gov (United States)

    Cazau, Dorian; Revillon, Guillaume; Krywyk, Julien; Adam, Olivier

    2015-10-01

    Automatic transcription of music is a long-studied research field with many operational systems available commercially. In this paper, a generic transcription system able to host various prior knowledge parameters has been developed, followed by an in-depth investigation of their impact on music transcription. Explicit links between musical knowledge and algorithmic formalism have been made. Musical knowledge covers classes of timbre, musicology, and playing style of an instrument repertoire. An evaluation sound corpus gathering musical pieces played by human performers from three different instrument repertoires, namely, classical piano, steel-string acoustic guitar, and the marovany zither from Madagascar, has been developed. The different components of musical knowledge have been successively incorporated in a complete transcription system, consisting mainly of a Probabilistic Latent Component Analysis algorithm post-processed with a Hidden Markov Model, and their impact on transcription results have been comparatively evaluated.

  2. Investigation on wind energy-compressed air power system.

    Science.gov (United States)

    Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

    2004-03-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  3. Investigating habits: strategies, technologies and models.

    Science.gov (United States)

    Smith, Kyle S; Graybiel, Ann M

    2014-01-01

    Understanding habits at a biological level requires a combination of behavioral observations and measures of ongoing neural activity. Theoretical frameworks as well as definitions of habitual behaviors emerging from classic behavioral research have been enriched by new approaches taking account of the identification of brain regions and circuits related to habitual behavior. Together, this combination of experimental and theoretical work has provided key insights into how brain circuits underlying action-learning and action-selection are organized, and how a balance between behavioral flexibility and fixity is achieved. New methods to monitor and manipulate neural activity in real time are allowing us to have a first look "under the hood" of a habit as it is formed and expressed. Here we discuss ideas emerging from such approaches. We pay special attention to the unexpected findings that have arisen from our own experiments suggesting that habitual behaviors likely require the simultaneous activity of multiple distinct components, or operators, seen as responsible for the contrasting dynamics of neural activity in both cortico-limbic and sensorimotor circuits recorded concurrently during different stages of habit learning. The neural dynamics identified thus far do not fully meet expectations derived from traditional models of the structure of habits, and the behavioral measures of habits that we have made also are not fully aligned with these models. We explore these new clues as opportunities to refine an understanding of habits.

  4. Investigation and Modelling of Diesel Hydrotreating Reactions

    DEFF Research Database (Denmark)

    Boesen, Rasmus Risum

    This project consists of a series of studies, that are related to hydrotreating of diesel. Hy- drotreating is an important refinery process, in which the oil stream is upgraded to meet the required environmental specifications and physical properties. Although hydrotreating is a ma- ture technology...... it has received increased attention within the last decade due to tightened legislations regarding the sulfur content, e.g. the demand for Ultra Low Sulfur Diesel (ULSD) with a maximum sulfur content of as low as 10 ppm S has increased. The process is complex, as the performance of a hydrotreating...... due to a stronger adsorption on hydrogenation sites. Since feeds used in the hydrotreating process, usually gas-oils, are complex mixtures with a large number of compounds, analysis of the reactions of individual compounds can be difficult. In this work a model-diesel feed consisting of 13 different...

  5. Investigation on Evolutionary Computation Techniques of a Nonlinear System

    Directory of Open Access Journals (Sweden)

    Tran Trong Dao

    2011-01-01

    Full Text Available The main aim of this work is to show that such a powerful optimizing tool like evolutionary algorithms (EAs can be in reality used for the simulation and optimization of a nonlinear system. A nonlinear mathematical model is required to describe the dynamic behaviour of batch process; this justifies the use of evolutionary method of the EAs to deal with this process. Four algorithms from the field of artificial intelligent—differential evolution (DE, self-organizing migrating algorithm (SOMA, genetic algorithm (GA, and simulated annealing (SA—are used in this investigation. The results show that EAs are used successfully in the process optimization.

  6. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    The core characteristics of tactile stimuli, i.e., recognition reliability and tolerance to ambient interference, make them an ideal candidate to be integrated into a symbiotic system. The selection of the appropriate stimulation is indeed important in order not to hinder the interaction from...... the user’s perspective. Here we present the process of selecting the most adequate tactile stimulation delivered by a tactile vest while users were engaged in an absorbing activity, namely playing a video-game. A total of 20 participants (mean age 24.78; SD= 1.57) were involved. Among the eight tactile...

  7. Zebrafish as a model to investigate CNS myelination.

    Science.gov (United States)

    Preston, Marnie A; Macklin, Wendy B

    2015-02-01

    Myelin plays a critical role in proper neuronal function by providing trophic and metabolic support to axons and facilitating energy-efficient saltatory conduction. Myelination is influenced by numerous molecules including growth factors, hormones, transmembrane receptors and extracellular molecules, which activate signaling cascades that drive cellular maturation. Key signaling molecules and downstream signaling cascades controlling myelination have been identified in cell culture systems. However, in vitro systems are not able to faithfully replicate the complex in vivo signaling environment that occurs during development or following injury. Currently, it remains time-consuming and expensive to investigate myelination in vivo in rodents, the most widely used model for studying mammalian myelination. As such, there is a need for alternative in vivo myelination models, particularly ones that can test molecular mechanisms without removing oligodendrocyte lineage cells from their native signaling environment or disrupting intercellular interactions with other cell types present during myelination. Here, we review the ever-increasing role of zebrafish in studies uncovering novel mechanisms controlling vertebrate myelination. These innovative studies range from observations of the behavior of single cells during in vivo myelination as well as mutagenesis- and pharmacology-based screens in whole animals. Additionally, we discuss recent efforts to develop novel models of demyelination and oligodendrocyte cell death in adult zebrafish for the study of cellular behavior in real time during repair and regeneration of damaged nervous systems. © 2014 Wiley Periodicals, Inc.

  8. Investigations on the feedback system of ASDEX

    International Nuclear Information System (INIS)

    Schneider, F.; Gresser, F.

    1976-01-01

    The plasma position in ASDEX will be safeguarded from radial displacement by a thyristor-operated vertical field control circuit, from vertical displacement by a radial field control circuit with power transistors. In both control circuits the electrodynamic properties of the non-circular, slit vacuum vessel with its divertor inserts play a big role. The essential magnetic couplings and time constants were therefore determined in a model of ASDEX. These dynamic properties and the inter-related plasma physics are represented by means of feedback technology. The control processes are computed by the root locus method and Laplace transformation. For optimizing purposes, use is made of graphic methods such as conformal mapping in Nichols diagrams. The problems entailed in fast feedback control with thyristors are thereby given special attention. (orig.) [de

  9. System Level Modelling and Performance Estimation of Embedded Systems

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer

    The advances seen in the semiconductor industry within the last decade have brought the possibility of integrating evermore functionality onto a single chip forming functionally highly advanced embedded systems. These integration possibilities also imply that as the design complexity increases, so...... an efficient system level design methodology, a modelling framework for performance estimation and design space exploration at the system level is required. This thesis presents a novel component based modelling framework for system level modelling and performance estimation of embedded systems. The framework...... is performed by having the framework produce detailed quantitative information about the system model under investigation. The project is part of the national Danish research project, Danish Network of Embedded Systems (DaNES), which is funded by the Danish National Advanced Technology Foundation. The project...

  10. Modeling and estimating system availability

    International Nuclear Information System (INIS)

    Gaver, D.P.; Chu, B.B.

    1976-11-01

    Mathematical models to infer the availability of various types of more or less complicated systems are described. The analyses presented are probabilistic in nature and consist of three parts: a presentation of various analytic models for availability; a means of deriving approximate probability limits on system availability; and a means of statistical inference of system availability from sparse data, using a jackknife procedure. Various low-order redundant systems are used as examples, but extension to more complex systems is not difficult

  11. Performance based investigations of structural systems under fire

    DEFF Research Database (Denmark)

    Gentili, Filippo; Crosti, Chiara; Giuliani, Luisa

    2010-01-01

    Prescriptive measures and procedures developed over the past here are mostly aimed at preventing structural failures of single elements for the time required for the evacuation. The response to fire and fire effects of the structural system as a whole remains often unknown and the survival of the...... structures are presented and discussed, with particular attention to methodological aspects. The effects of different assumptions in the modeling and in the definition of the collapse are highlighted, as critical aspects of a performance-based investigation....... these kinds of events, the mitigation of possible collapse induced by fire should be achieved. In this respect, a performance-based investigation of the structure aimed at highlight fire effects and fire-induced collapse mechanisms becomes of interest. In the paper collapse mechanisms of some simple...

  12. A robotic model to investigate human motor control.

    Science.gov (United States)

    Lenzi, Tommaso; Vitiello, Nicola; McIntyre, Joseph; Roccella, Stefano; Carrozza, Maria Chiara

    2011-07-01

    The role of the mechanical properties of the neuromuscular system in motor control has been investigated for a long time in both human and animal subjects, mainly through the application of mechanical perturbations to the limb during natural movements and the observation of its corrective responses. These methods have provided a wealth of insight into how the central nervous system controls the limb. They suffer, however, from the fact that it is almost impossible to separate the active and passive components of the measured arm stiffness and that the measurement may themselves alter the stiffness characteristic of the arm. As a complement to these analyses, the implementation of a given neuroscientific hypothesis on a real mechanical system could overcome these measurement artifact and provide a tool that is, under full control of the experimenter, able to replicate the relevant functional features of the human arm. In this article, we introduce the NEURARM platform, a robotic arm intended to test hypotheses on the human motor control system. As such, NEURARM satisfies two key requirements. First, its kinematic parameters and inertia are similar to that of the human arm. Second, NEURARM mimics the main physical features of the human actuation system, specifically, the use of tendons to transfer force, the presence of antagonistic muscle pairs, the passive elasticity of muscles in the absence of any neural feedback and the non-linear elastic behaviour. This article presents the design and characterization of the NEURARM actuation system. The resulting mechanical behaviour, which has been tested in joint and Cartesian space under static and dynamic conditions, proves that the NEURARM platform can be exploited as a robotic model of the human arm, and could thus represent a powerful tool for neuroscience investigations.

  13. Investigation on flow stability of supercritical water cooled systems

    International Nuclear Information System (INIS)

    Cheng, X.; Kuang, B.

    2006-01-01

    Research activities are ongoing worldwide to develop nuclear power plants with supercritical water cooled reactor (SCWR) with the purpose to achieve a high thermal efficiency and to improve their economical competitiveness. However, the strong variation of the thermal-physical properties of water in the vicinity of the pseudo-critical line results in challenging tasks in various fields, e.g. thermal-hydraulic design of a SCWR. One of the challenging tasks is to understand and to predict the dynamic behavior of supercritical water cooled systems. Although many thermal-hydraulic research activities were carried out worldwide in the past as well as in the near present, studies on dynamic behavior and flow stability of SC water cooled systems are scare. Due to the strong density variation, flow stability is expected to be one of the key items which need to be taken into account in the design of a SCWR. In the present work, the dynamic behavior and flow stability of SC water cooled systems are investigated using both numerical and theoretical approaches. For this purpose a new computer code SASC was developed, which can be applied to analysis the dynamic behavior of systems cooled by supercritical fluids. In addition, based on the assumptions of a simplified system, a theoretical model was derived for the prediction of the onset of flow instability. A comparison was made between the results obtained using the theoretical model and those from the SASC code. A good agreement was achieved. This gives the first evidence of the reliability of both the SASC code and the theoretical model

  14. Investigation of a Gamma model for mixture STR samples

    DEFF Research Database (Denmark)

    Christensen, Susanne; Bøttcher, Susanne Gammelgaard; Lauritzen, Steffen L.

    The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis.......The behaviour of PCR Amplification Kit, when used for mixture STR samples, is investigated. A model based on the Gamma distribution is fitted to the amplifier output for constructed mixtures, and the assumptions of the model is evaluated via residual analysis....

  15. Modelling of reverberation enhancement systems

    OpenAIRE

    ROUCH , Jeremy; Schmich , Isabelle; Galland , Marie-Annick

    2012-01-01

    International audience; Electroacoustic enhancement systems are increasingly specified by acoustic consultants to address the requests for a multi-purpose use of performance halls. However, there is still a lack of simple models to predict the effect induced by these systems on the acoustic field. Two models are introduced to establish the impulse responses of a room equipped with a reverberation enhancement system. These models are based on passive impulse responses according to the modified...

  16. MODELLING OF MATERIAL FLOW SYSTEMS

    OpenAIRE

    PÉTER TELEK

    2012-01-01

    Material flow systems are in generally very complex processes. During design, building and operation of complex systems there are many different problems. If these complex processes can be described in a simple model, the tasks will be clearer, better adaptable and easier solvable. As the material flow systems are very different, so using models is a very important aid to create uniform methods and solutions. This paper shows the details of the application possibilities of modelling in the ma...

  17. Dynamic Modeling of ALS Systems

    Science.gov (United States)

    Jones, Harry

    2002-01-01

    The purpose of dynamic modeling and simulation of Advanced Life Support (ALS) systems is to help design them. Static steady state systems analysis provides basic information and is necessary to guide dynamic modeling, but static analysis is not sufficient to design and compare systems. ALS systems must respond to external input variations and internal off-nominal behavior. Buffer sizing, resupply scheduling, failure response, and control system design are aspects of dynamic system design. We develop two dynamic mass flow models and use them in simulations to evaluate systems issues, optimize designs, and make system design trades. One model is of nitrogen leakage in the space station, the other is of a waste processor failure in a regenerative life support system. Most systems analyses are concerned with optimizing the cost/benefit of a system at its nominal steady-state operating point. ALS analysis must go beyond the static steady state to include dynamic system design. All life support systems exhibit behavior that varies over time. ALS systems must respond to equipment operating cycles, repair schedules, and occasional off-nominal behavior or malfunctions. Biological components, such as bioreactors, composters, and food plant growth chambers, usually have operating cycles or other complex time behavior. Buffer sizes, material stocks, and resupply rates determine dynamic system behavior and directly affect system mass and cost. Dynamic simulation is needed to avoid the extremes of costly over-design of buffers and material reserves or system failure due to insufficient buffers and lack of stored material.

  18. Modeling soft interface dominated systems

    NARCIS (Netherlands)

    Lamorgese, A.; Mauri, R.; Sagis, L.M.C.

    2017-01-01

    The two main continuum frameworks used for modeling the dynamics of soft multiphase systems are the Gibbs dividing surface model, and the diffuse interface model. In the former the interface is modeled as a two dimensional surface, and excess properties such as a surface density, or surface energy

  19. Validation of systems biology models

    NARCIS (Netherlands)

    Hasdemir, D.

    2015-01-01

    The paradigm shift from qualitative to quantitative analysis of biological systems brought a substantial number of modeling approaches to the stage of molecular biology research. These include but certainly are not limited to nonlinear kinetic models, static network models and models obtained by the

  20. From Numeric Models to Granular System Modeling

    Directory of Open Access Journals (Sweden)

    Witold Pedrycz

    2015-03-01

    To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.

  1. Amor: Investigating The Triple Asteroid System 2001 SN263

    Science.gov (United States)

    Jones, T.; Bellerose, Julie; Lee, P.; Prettyman, T.; Lawrence, D.; Smith, P.; Gaffey, M.; Nolan, M.; Goldsten, J.; Thomas, P.; Veverka, J.; Farquhar, R.; Heldmann, J.; Reddy, V.; Williams, B.; Chartres, J.; DeRosee, R.; Dunham, D.

    2010-10-01

    The Amor mission will rendezvous and land at the triple Near-Earth Asteroid system (153591) 2001 SN263 and execute detailed, in-situ science investigations. The spacecraft reaches 2001 SN263 by using a two-year ΔVEGA (ΔV-Earth Gravity Assist) trajectory with a relatively low launch C3 of 33.5 km2/s2. Rendezvous will enable reconnaissance activities including global and regional imaging, shape modeling, system dynamics, and compositional mapping. After landing, Amor will conduct in-situ imaging (panoramic to microscopic scale) and compositional measurements to include elemental abundance. The main objectives are to 1) establish in-situ the long-hypothesized link between C-type asteroids and the primitive carbonaceous chondrite (CC) meteorites, 2) investigate the nature, origin and evolution of C-type asteroids, and 3) investigate the origin and evolution of a multiple asteroid system. The mission also addresses the distribution of volatiles and organic materials, impact hazards, and resources for future exploration. Amor is managed by NASA Ames Research Center in partnership with Orbital Sciences, KinetX, MDA, and Draper with heritage instruments provided by Ball Aerospace, JHU/APL, and Firestar Engineering. The science team brings experience from NEAR, Hayabusa, Deep Impact, Dawn, LCROSS, Kepler, and Mars missions. In this paper, we describe the science, mission design, and main operational challenges of performing in-situ science at this triple asteroid system. Challenges include landing on the asteroid components, thermal environment, short day-night cycles, and the operation of deployed instruments in a low gravity (10^-5 g) environment.

  2. Coastal Modeling System Advanced Topics

    Science.gov (United States)

    2012-06-18

    22 June 2012 - Day 5  Debugging and Problem solving  Model Calibration  Post-processing Coastal and Hydraulics Laboratory Focus of...Efficiently: • The setup process is fast and without wasted time or effort 3 Coastal and Hydraulics Laboratory 4 Coastal Modeling System (CMS) What...is the CMS? Integrated wave, current, and morphology change model in the Surface- water Modeling System (SMS). Why CMS? Operational at 10

  3. Safeguards system effectiveness modeling

    International Nuclear Information System (INIS)

    Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.

    1976-01-01

    A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. The overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined

  4. Safeguards system effectiveness modeling

    International Nuclear Information System (INIS)

    Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.

    1976-01-01

    A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. In this paper, the overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined

  5. Human performance modeling for system of systems analytics.

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kevin R.; Lawton, Craig R.; Basilico, Justin Derrick; Longsine, Dennis E. (INTERA, Inc., Austin, TX); Forsythe, James Chris; Gauthier, John Henry; Le, Hai D.

    2008-10-01

    A Laboratory-Directed Research and Development project was initiated in 2005 to investigate Human Performance Modeling in a System of Systems analytic environment. SAND2006-6569 and SAND2006-7911 document interim results from this effort; this report documents the final results. The problem is difficult because of the number of humans involved in a System of Systems environment and the generally poorly defined nature of the tasks that each human must perform. A two-pronged strategy was followed: one prong was to develop human models using a probability-based method similar to that first developed for relatively well-understood probability based performance modeling; another prong was to investigate more state-of-art human cognition models. The probability-based modeling resulted in a comprehensive addition of human-modeling capability to the existing SoSAT computer program. The cognitive modeling resulted in an increased understanding of what is necessary to incorporate cognition-based models to a System of Systems analytic environment.

  6. Analysis of Systems Hardware Flown on LDEF-Results of the Systems Special Investigation Group

    National Research Council Canada - National Science Library

    Dursch, H

    1992-01-01

    .... The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long term exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware...

  7. Investigation of Various Novel Air-Breathing Propulsion Systems

    Science.gov (United States)

    Wilhite, Jarred M.

    The current research investigates the operation and performance of various air-breathing propulsion systems, which are capable of utilizing different types of fuel. This study first focuses on a modular RDE configuration, which was mainly studied to determine which conditions yield stable, continuous rotating detonation for an ethylene-air mixture. The performance of this RDE was analyzed by studying various parameters such as mass flow rate, equivalence ratios, wave speed and cell size. For relatively low mass flow rates near stoichiometric conditions, a rotating detonation wave is observed for an ethylene-RDE, but at speeds less than an ideal detonation wave. The current research also involves investigating the newly designed, Twin Oxidizer Injection Capable (TOXIC) RDE. Mixtures of hydrogen and air were utilized for this configuration, resulting in sustained rotating detonation for various mass flow rates and equivalence ratios. A thrust stand was also developed to observe and further measure the performance of the TOXIC RDE. Further analysis was conducted to accurately model and simulate the response of thrust stand during operation of the RDE. Also included in this research are findings and analysis of a propulsion system capable of operating on the Inverse Brayton Cycle. The feasibility of this novel concept was validated in a previous study to be sufficient for small-scale propulsion systems, namely UAV applications. This type of propulsion system consists of a reorganization of traditional gas turbine engine components, which incorporates expansion before compression. This cycle also requires a heat exchanger to reduce the temperature of the flow entering the compressor downstream. While adding a heat exchanger improves the efficiency of the cycle, it also increases the engine weight, resulting in less endurance for the aircraft. Therefore, this study focuses on the selection and development of a new heat exchanger design that is lightweight, and is capable

  8. Finding Positive Feedback Loops in Environmental Models: A Mathematical Investigation

    Science.gov (United States)

    Sheikholeslami, R.; Razavi, S.

    2016-12-01

    Dynamics of most earth and environmental systems are generally governed by interactions between several hydrological (e.g., soil moisture and precipitation), geological (e.g., and erosion), geochemical (e.g., nutrient loading), and atmospheric (e.g., temperature) processes which operate on a range of spatio-temporal scales. These interactions create numerous feedback mechanisms with complex behaviours, and their understanding and representation can vary depending on the scale in space and/or time at which the system is analyzed. One of the most crucial characteristics of such complex systems is the existence of positive feedback loops. The presence of positive feedbacks may increase complexity, accelerate change, or trigger multiple stable states in the underlying dynamical system. Furthermore, because of the inherent non-linearity, it is often very difficult to obtain a general idea of their complex dynamics. Feedback loops in environmental systems have been well recognized and qualitatively discussed. With a quantitative/mathematical view, in this presentation, we address the question of how the positive feedback loops can be identified/implemented in environmental models. We investigate the nature of different feedback mechanisms and dynamics of simple example case studies that underlie fundamental processes such as vegetation, precipitation and soil moisture. To do this, we apply the concept of "interaction graph" from mathematics which is built from the Jacobian matrix of the dynamical system. The Jacobian matrix contains information on how variations of one state variable depends on variations of other variables, and thus can be used to understand the dynamical possibilities of feedback mechanisms in the underlying system. Moreover, this study highlights that there are some situations where the existence of positive feedback loops can cause multiple stable states, and thereby regime shifts in environmental systems. Systems with multiple stable states are

  9. Investigation of antidepressant mechanisms in an animal model of depression

    Energy Technology Data Exchange (ETDEWEB)

    Jesberger, J.A.

    1984-01-01

    The rat olfactory bulbectomy model has recently been found to exhibit good predictive properties when used to screen drugs for antidepressant activity, thereby suggesting that it may have a pathological defect particularly sensitive to the antidepressant activity of drugs. This model, with its well defined behavioral syndrome, was thus used to investigate some neurochemical effects of 4 species of antidepressant drugs and to see if drug actions varied between the normal and pathological states. A major finding in the study was the regional variation in /sup 3/H-imipramine binding and beta receptor density following the lesion. In addition treatment of normal rats with one of the 4 different antidepressant drugs caused changes in the density of /sup 3/H-imipramine recognition sites and beta receptors that varied between the 4 regions examined and with the drug administered such that none of the 4 drugs had identical response profiles. This suggests that the different drugs may be acting on different neurochemical substrates and that the distribution and sensitivity of the substrate varies for the different brain regions. Furthermore, results obtained in this investigation suggests that the effects of some antidepressant drugs on noradrenergic and serotonergic systems are markedly state-dependent and that this varies between different brain regions.

  10. Simulated, Emulated, and Physical Investigative Analysis (SEPIA) of networked systems.

    Energy Technology Data Exchange (ETDEWEB)

    Burton, David P.; Van Leeuwen, Brian P.; McDonald, Michael James; Onunkwo, Uzoma A.; Tarman, Thomas David; Urias, Vincent E.

    2009-09-01

    This report describes recent progress made in developing and utilizing hybrid Simulated, Emulated, and Physical Investigative Analysis (SEPIA) environments. Many organizations require advanced tools to analyze their information system's security, reliability, and resilience against cyber attack. Today's security analysis utilize real systems such as computers, network routers and other network equipment, computer emulations (e.g., virtual machines) and simulation models separately to analyze interplay between threats and safeguards. In contrast, this work developed new methods to combine these three approaches to provide integrated hybrid SEPIA environments. Our SEPIA environments enable an analyst to rapidly configure hybrid environments to pass network traffic and perform, from the outside, like real networks. This provides higher fidelity representations of key network nodes while still leveraging the scalability and cost advantages of simulation tools. The result is to rapidly produce large yet relatively low-cost multi-fidelity SEPIA networks of computers and routers that let analysts quickly investigate threats and test protection approaches.

  11. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P

    2007-01-01

    All phenomena in nature are characterized by motion; this is an essential property of matter, having infinitely many aspects. Motion can be mechanical, physical, chemical or biological, leading to various sciences of nature, mechanics being one of them. Mechanics deals with the objective laws of mechanical motion of bodies, the simplest form of motion. In the study of a science of nature mathematics plays an important role. Mechanics is the first science of nature which was expressed in terms of mathematics by considering various mathematical models, associated to phenomena of the surrounding nature. Thus, its development was influenced by the use of a strong mathematical tool; on the other hand, we must observe that mechanics also influenced the introduction and the development of many mathematical notions. In this respect, the guideline of the present book is precisely the mathematical model of mechanics. A special accent is put on the solving methodology as well as on the mathematical tools used; vectors, ...

  12. Stochastic Modelling of Energy Systems

    DEFF Research Database (Denmark)

    Andersen, Klaus Kaae

    2001-01-01

    In this thesis dynamic models of typical components in Danish heating systems are considered. Emphasis is made on describing and evaluating mathematical methods for identification of such models, and on presentation of component models for practical applications. The thesis consists of seven...... of component models, such as e.g. heat exchanger and valve models, adequate for system simulations. Furthermore, the thesis demonstrates and discusses the advantages and disadvantages of using statistical methods in conjunction with physical knowledge in establishing adequate component models of heating...... research papers (case studies) together with a summary report. Each case study takes it's starting point in typical heating system components and both, the applied mathematical modelling methods and the application aspects, are considered. The summary report gives an introduction to the scope...

  13. Analysis of a Mathematical Model to Investigate the Dynamics of ...

    African Journals Online (AJOL)

    In this paper, we formulated a compartmental model to investigate the dynamics of dengue fever in a population with some measure of disease control. We qualitatively and quantitatively analyzed the model and found that the model has a disease free equilibrium (DFE), an endemic equilibrium point and undergoes the ...

  14. Analysis of a Mathematical Model to Investigate the Dynamics of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: In this paper, we formulated a compartmental model to investigate the dynamics of dengue fever in a population with some measure of disease control. We qualitatively and quantitatively analyzed the model and found that the model has a disease free equilibrium. (DFE), an endemic equilibrium point and ...

  15. Investigating the Propagation of Meteorological Model Uncertainty for Tracer Modeling

    Science.gov (United States)

    Lopez-Coto, I.; Ghosh, S.; Karion, A.; Martin, C.; Mueller, K. L.; Prasad, K.; Whetstone, J. R.

    2016-12-01

    The North-East Corridor project aims to use a top-down inversion method to quantify sources of Greenhouse Gas (GHG) emissions in the urban areas of Washington DC and Baltimore at approximately 1km2 resolutions. The aim of this project is to help establish reliable measurement methods for quantifying and validating GHG emissions independently of the inventory methods typically used to guide mitigation efforts. Since inversion methods depend strongly on atmospheric transport modeling, analyzing the uncertainties on the meteorological fields and their propagation through the sensitivities of observations to surface fluxes (footprints) is a fundamental step. To this end, six configurations of the Weather Research and Forecasting Model (WRF-ARW) version 3.8 were used to generate an ensemble of meteorological simulations. Specifically, we used 4 planetary boundary layer parameterizations (YSU, MYNN2, BOULAC, QNSE), 2 sources of initial and boundary conditions (NARR and HRRR) and 1 configuration including the building energy parameterization (BEP) urban canopy model. The simulations were compared with more than 150 meteorological surface stations, a wind profiler and radiosondes for a month (February) in 2016 to account for the uncertainties and the ensemble spread for wind speed, direction and mixing height. In addition, we used the Stochastic Time-Inverted Lagrangian Transport model (STILT) to derive the sensitivity of 12 hypothetical observations to surface emissions (footprints) with each WRF configuration. The footprints and integrated sensitivities were compared and the resulting uncertainties estimated.

  16. Investigation of faulted tunnel models by combined photoelasticity and finite element analysis

    International Nuclear Information System (INIS)

    Ladkany, S.G.; Huang, Y.

    1994-01-01

    Models of square and circular tunnels with short faults cutting through their surfaces are investigated by photoelasticity. These models, when duplicated by finite element analysis can predict the stress states of square or circular faulted tunnels adequately. Finite element analysis, using gap elements, may be used to investigate full size faulted tunnel system

  17. A strategic review of electricity systems models

    International Nuclear Information System (INIS)

    Foley, A.M.; O Gallachoir, B.P.; McKeogh, E.J.; Hur, J.; Baldick, R.

    2010-01-01

    Electricity systems models are software tools used to manage electricity demand and the electricity systems, to trade electricity and for generation expansion planning purposes. Various portfolios and scenarios are modelled in order to compare the effects of decision making in policy and on business development plans in electricity systems so as to best advise governments and industry on the least cost economic and environmental approach to electricity supply, while maintaining a secure supply of sufficient quality electricity. The modelling techniques developed to study vertically integrated state monopolies are now applied in liberalised markets where the issues and constraints are more complex. This paper reviews the changing role of electricity systems modelling in a strategic manner, focussing on the modelling response to key developments, the move away from monopoly towards liberalised market regimes and the increasing complexity brought about by policy targets for renewable energy and emissions. The paper provides an overview of electricity systems modelling techniques, discusses a number of key proprietary electricity systems models used in the USA and Europe and provides an information resource to the electricity analyst not currently readily available in the literature on the choice of model to investigate different aspects of the electricity system. (author)

  18. Model Reduction of Hybrid Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    for model reduction of switched systems is based on the switching generalized gramians. The reduced order switched system is guaranteed to be stable for all switching signal in this method. This framework uses stability conditions which are based on switching quadratic Lyapunov functions which are less...... conservative than the stability conditions based on common quadratic Lyapunov functions. The stability conditions which are used for this method are very useful in model reduction and design problems because they have slack variables in the conditions. Similar conditions for a class of switched nonlinear......High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...

  19. Investigating Master Students’ Mental Models of Google Search Engine

    Directory of Open Access Journals (Sweden)

    Azam Safari

    2017-09-01

    According to the findings, it is necessary to consider mental model as a factor affecting information seeking behavior, in designing information systems and training users too. Understanding users’ mental models reveal their errors, misconceptions and knowledge gaps, and by this pathology, it is possible to correct these faults and flaws and increase the effectiveness of the system and training.

  20. Distribution system modeling and analysis

    CERN Document Server

    Kersting, William H

    2001-01-01

    For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures. Distribution System Modeling and Analysis helps prevent those errors. It gives readers a basic understanding of the modeling and operating characteristics of the major components of a distribution system. One by one, the author develops and analyzes each component as a stand-alone element, then puts them all together to analyze a distribution system comprising the various shunt and series devices for power-flow and short-circuit studies. He includes the derivation of all models and includes many num...

  1. Hydronic distribution system computer model

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Strasser, J.J.

    1994-10-01

    A computer model of a hot-water boiler and its associated hydronic thermal distribution loop has been developed at Brookhaven National Laboratory (BNL). It is intended to be incorporated as a submodel in a comprehensive model of residential-scale thermal distribution systems developed at Lawrence Berkeley. This will give the combined model the capability of modeling forced-air and hydronic distribution systems in the same house using the same supporting software. This report describes the development of the BNL hydronics model, initial results and internal consistency checks, and its intended relationship to the LBL model. A method of interacting with the LBL model that does not require physical integration of the two codes is described. This will provide capability now, with reduced up-front cost, as long as the number of runs required is not large.

  2. Models for large superconducting toroidal magnet systems

    International Nuclear Information System (INIS)

    Arendt, F.; Brechna, H.; Erb, J.; Komarek, P.; Krauth, H.; Maurer, W.

    1976-01-01

    Prior to the design of large GJ toroidal magnet systems it is appropriate to procure small scale models, which can simulate their pertinent properties and allow to investigate their relevant phenomena. The important feature of the model is to show under which circumstances the system performance can be extrapolated to large magnets. Based on parameters such as the maximum magnetic field and the current density, the maximum tolerable magneto-mechanical stresses, a simple method of designing model magnets is presented. It is shown how pertinent design parameters are changed when the toroidal dimensions are altered. In addition some conductor cost estimations are given based on reactor power output and wall loading

  3. Expedition Earth and Beyond: Student Scientist Guidebook. Model Research Investigation

    Science.gov (United States)

    Graff, Paige Valderrama

    2009-01-01

    The Expedition Earth and Beyond Student Scientist Guidebook is designed to help student researchers model the process of science and conduct a research investigation. The Table of Contents listed outlines the steps included in this guidebook

  4. Intrusion detection: systems and models

    Science.gov (United States)

    Sherif, J. S.; Dearmond, T. G.

    2002-01-01

    This paper puts forward a review of state of the art and state of the applicability of intrusion detection systems, and models. The paper also presents a classfication of literature pertaining to intrusion detection.

  5. Plant and safety system model

    International Nuclear Information System (INIS)

    Beltracchi, Leo

    1999-01-01

    The design and development of a digital computer-based safety system for a nuclear power plant is a complex process. The process of design and product development must result in a final product free of critical errors; operational safety of nuclear power plants must not be compromised. This paper focuses on the development of a safety system model to assist designers, developers, and regulators in establishing and evaluating requirements for a digital computer-based safety system. The model addresses hardware, software, and human elements for use in the requirements definition process. The purpose of the safety system model is to assist and serve as a guide to humans in the cognitive reasoning process of establishing requirements. The goals in the use of the model are to: (1) enhance the completeness of the requirements and (2) reduce the number of errors associated with the requirements definition phase of a project

  6. Metabolic models to investigate energy limited anaerobic ecosystems.

    Science.gov (United States)

    Rodríguez, J; Premier, G C; Guwy, A J; Dinsdale, R; Kleerebezem, R

    2009-01-01

    Anaerobic wastewater treatment is shifting from a philosophy of solely pollutants removal to a philosophy of combined resource recovery and waste treatment. Simultaneous wastewater treatment with energy recovery in the form of energy rich products, brings renewed interest to non-methanogenic anaerobic bioprocesses such as the anaerobic production of hydrogen, ethanol, solvents, VFAs, bioplastics and even electricity from microbial fuel cells. The existing kinetic-based modelling approaches, widely used in aerobic and methanogenic wastewater treatment processes, do not seem adequate in investigating such energy limited microbial ecosystems. The great diversity of similar microbial species, which share many of the fermentative reaction pathways, makes quantify microbial groups very difficult and causes identifiability problems. A modelling approach based on the consideration of metabolic reaction networks instead of on separated microbial groups is suggested as an alternative to describe anaerobic microbial ecosystems and in particular for the prediction of product formation as a function of environmental conditions imposed. The limited number of existing relevant fermentative pathways in conjunction with the fact that anaerobic reactions proceed very close to thermodynamic equilibrium reduces the complexity of such approach and the degrees of freedom in terms of product formation fluxes. In addition, energy limitation in these anaerobic microbial ecosystems makes plausible that selective forces associated with energy further define the system activity by favouring those conversions/microorganisms which provide the most energy for growth under the conditions imposed.

  7. The Applicability of Selected Evaluation Models to Evolving Investigative Designs.

    Science.gov (United States)

    Smith, Nick L.; Hauer, Diane M.

    1990-01-01

    Ten evaluation models are examined in terms of their applicability to investigative, emergent design programs: Stake's portrayal, Wolf's adversary, Patton's utilization, Guba's investigative journalism, Scriven's goal-free, Scriven's modus operandi, Eisner's connoisseurial, Stufflebeam's CIPP, Tyler's objective based, and Levin's cost…

  8. Investigation of Transonic Wake Dynamics for Mechanically Deployable Entry Systems

    Science.gov (United States)

    Stern, Eric; Barnhardt, Michael; Venkatapathy, Ethiraj; Candler, Graham; Prabhu, Dinesh

    2012-01-01

    A numerical investigation of transonic flow around a mechanically deployable entry system being considered for a robotic mission to Venus has been performed, and preliminary results are reported. The flow around a conceptual representation of the vehicle geometry was simulated at discrete points along a ballistic trajectory using Detached Eddy Simulation (DES). The trajectory points selected span the low supersonic to transonic regimes with freestream Mach numbers from 1:5 to 0:8, and freestream Reynolds numbers (based on diameter) between 2:09 x 10(exp 6) and 2:93 x 10(exp 6). Additionally, the Mach 0:8 case was simulated at angles of attack between 0 and 5 . Static aerodynamic coefficients obtained from the data show qualitative agreement with data from 70deg sphere-cone wind tunnel tests performed for the Viking program. Finally, the effect of choices of models and numerical algorithms is addressed by comparing the DES results to those using a Reynolds Averaged Navier-Stokes (RANS) model, as well as to results using a more dissipative numerical scheme.

  9. A descriptive ecosystem model - a strategy for model development during site investigations

    International Nuclear Information System (INIS)

    Loefgren, Anders

    2003-09-01

    This report describes a strategy for the development of a site descriptive model for the surface ecosystem on the potential deep repository sites. The surface ecosystem embraces many disciplines, and these have to be identified, described and integrated in order to construct a descriptive ecosystem model that describes and quantifies biotic and abiotic patterns and processes of importance for the ecosystem on the site. The descriptive model includes both present day conditions and historical information. The descriptive ecosystem model will be used to supply input data for the safety assessment and to serve as the baseline model for devising a monitoring program to detect short-term disturbances caused first by the site investigations and later by the construction of the deep repository. Furthermore, it will serve as a reference for future comparisons to determine more long-term effects or changes caused by the deep repository. The report adopts a non-site-specific approach focusing on the following aims: 1. To present and define the properties that will constitute the descriptive ecosystem model. 2. To present a methodology for determining those properties. 3. To describe and develop the framework for the descriptive ecosystem model by integrating the different properties. 4. To present vital data from other site descriptive models such as those for geology or hydrogeology that interacts with and affects the descriptive ecosystem model. The properties are described under four different sections: general physical properties of the landscape, the terrestrial system, the limnic system and the marine system. These headings are further subdivided into entities that integrate properties in relation to processes

  10. A descriptive ecosystem model - a strategy for model development during site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders [Stockholm Univ. (Sweden). Dept. of Botany; Lindborg, Tobias [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2003-09-01

    This report describes a strategy for the development of a site descriptive model for the surface ecosystem on the potential deep repository sites. The surface ecosystem embraces many disciplines, and these have to be identified, described and integrated in order to construct a descriptive ecosystem model that describes and quantifies biotic and abiotic patterns and processes of importance for the ecosystem on the site. The descriptive model includes both present day conditions and historical information. The descriptive ecosystem model will be used to supply input data for the safety assessment and to serve as the baseline model for devising a monitoring program to detect short-term disturbances caused first by the site investigations and later by the construction of the deep repository. Furthermore, it will serve as a reference for future comparisons to determine more long-term effects or changes caused by the deep repository. The report adopts a non-site-specific approach focusing on the following aims: 1. To present and define the properties that will constitute the descriptive ecosystem model. 2. To present a methodology for determining those properties. 3. To describe and develop the framework for the descriptive ecosystem model by integrating the different properties. 4. To present vital data from other site descriptive models such as those for geology or hydrogeology that interacts with and affects the descriptive ecosystem model. The properties are described under four different sections: general physical properties of the landscape, the terrestrial system, the limnic system and the marine system. These headings are further subdivided into entities that integrate properties in relation to processes.

  11. Investigating the LGBTQ Responsive Model for Supervision of Group Work

    Science.gov (United States)

    Luke, Melissa; Goodrich, Kristopher M.

    2013-01-01

    This article reports an investigation of the LGBTQ Responsive Model for Supervision of Group Work, a trans-theoretical supervisory framework to address the needs of lesbian, gay, bisexual, transgender, and questioning (LGBTQ) persons (Goodrich & Luke, 2011). Findings partially supported applicability of the LGBTQ Responsive Model for Supervision…

  12. Investigation in Query System Framework for High Energy Physics

    CERN Document Server

    Jatuphattharachat, Thanat

    2017-01-01

    We summarize an investigation in query system framework for HEP (High Energy Physics). Our work was an investigation on distributed server part of Femtocode, which is a query language that provides the ability for physicists to make plots and other aggregations in real-time. To make the system more robust and capable of processing large amount of data quickly, it is necessary to deploy the system on a redundant and distributed computing cluster. This project aims to investigate third party coordination and resource management frameworks which fit into the design of real-time distributed query system. Zookeeper, Mesos and Marathon are the main frameworks for this investigation. The results indicate that Zookeeper is good for job coordinator and job tracking as it provides robust, fast, simple and transparent read and write process for all connecting client across distributed Zookeeper server. Furthermore, it also supports high availability access and consistency guarantee within specific time bound.

  13. ABSTRACT MODELS FOR SYSTEM VIRTUALIZATION

    Directory of Open Access Journals (Sweden)

    M. G. Koveshnikov

    2015-05-01

    Full Text Available The paper is dedicated to issues of system objects securing (system files and user system or application configuration files against unauthorized access including denial of service attacks. We have suggested the method and developed abstract system virtualization models, which are used toresearch attack scenarios for different virtualization modes. Estimation for system tools virtualization technology effectiveness is given. Suggested technology is based on redirection of access requests to system objects shared among access subjects. Whole and partial system virtualization modes have been modeled. The difference between them is the following: in the whole virtualization mode all copies of access system objects are created whereon subjects’ requests are redirected including corresponding application objects;in the partial virtualization mode corresponding copies are created only for part of a system, for example, only system objects for applications. Alternative solutions effectiveness is valued relating to different attack scenarios. We consider proprietary and approved technical solution which implements system virtualization method for Microsoft Windows OS family. Administrative simplicity and capabilities of correspondingly designed system objects security tools are illustrated on this example. Practical significance of the suggested security method has been confirmed.

  14. Experimental investigation of a dual purpose solar heating system

    International Nuclear Information System (INIS)

    Nematollahi, Omid; Alamdari, Pourya; Assari, Mohammad Reza

    2014-01-01

    Highlights: • A dual purpose water and air heating system experimentally investigated. • This system can be used to heat water and air simultaneously. • Water can be used as a PCM material for heating air through the night. • Dual purpose systems achieve greater efficiency and lower heat dissipation. • Average efficiency of dual purpose system is 4% higher than single purpose system. - Abstract: In this study, a dual purpose water and air heating system is experimentally investigated. The system consists of a dual purpose flat solar collector and a vertical water storage tank. Water and air have natural and forced convection in the collector, respectively. The reason why dual purpose systems are used is to achieve greater efficiency and lower heat dissipation. Furthermore, high temperature and high performance can be obtained using this solar collector. These systems can be used to heat water and air simultaneously or separately. The hot water can be utilized for domestic applications or as a PCM material for heating air through the night. Besides, the hot air can be used in air conditioning systems, industrial processes and dryers. Therefore, using these collectors brings high energy savings. Absorber plate temperature variation, storage tank average temperature, system efficiency and air velocity effects are presented. Moreover, hourly efficiency is compared for single purpose and dual purpose systems. The results indicate that the efficiency of the dual purpose system is 3 to 5% higher than a single purpose system

  15. Navier-Stokes wave models for investigations of breakwater characteristics

    CSIR Research Space (South Africa)

    Cannoo, BR

    2008-03-01

    Full Text Available The dynamics of full breakwater stability are of importance in coastal engineering, and numerical models are some of the tools that can be applied. Given the work that exists worldwide in numerical models of breakwaters and armour units, it appears that a... examines spectral wave diffraction and refraction, dolos contact dynamics, and experimental breakwater modelling. Wave interaction effects and turbulence effects on the stability of armour unit and rock beds have been investigated widely. Shallow...

  16. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  17. CTBT integrated verification system evaluation model supplement

    International Nuclear Information System (INIS)

    EDENBURN, MICHAEL W.; BUNTING, MARCUS; PAYNE, ARTHUR C. JR.; TROST, LAWRENCE C.

    2000-01-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0

  18. Modeling Multi-Level Systems

    CERN Document Server

    Iordache, Octavian

    2011-01-01

    This book is devoted to modeling of multi-level complex systems, a challenging domain for engineers, researchers and entrepreneurs, confronted with the transition from learning and adaptability to evolvability and autonomy for technologies, devices and problem solving methods. Chapter 1 introduces the multi-scale and multi-level systems and highlights their presence in different domains of science and technology. Methodologies as, random systems, non-Archimedean analysis, category theory and specific techniques as model categorification and integrative closure, are presented in chapter 2. Chapters 3 and 4 describe polystochastic models, PSM, and their developments. Categorical formulation of integrative closure offers the general PSM framework which serves as a flexible guideline for a large variety of multi-level modeling problems. Focusing on chemical engineering, pharmaceutical and environmental case studies, the chapters 5 to 8 analyze mixing, turbulent dispersion and entropy production for multi-scale sy...

  19. Expert Systems as a Mindtool To Facilitate Mental Model Learning.

    Science.gov (United States)

    Mason-Mason, Susan Dale; Tessmer, Martin A.

    2000-01-01

    This exploratory study investigated whether the process of constructing an expert system model promotes the formation of expert-like mental models. Discusses expert systems as mindtools, expert systems as learning tools, the assessment of mental models, results of pretests and posttests, and future research. (Contains 56 references.) (Author/LRW)

  20. Analysis of systems hardware flown on LDEF. Results of the systems special investigation group

    Science.gov (United States)

    Dursch, Harry W.; Spear, W. Steve; Miller, Emmett A.; Bohnhoff-Hlavacek, Gail L.; Edelman, Joel

    1992-01-01

    The Long Duration Exposure Facility (LDEF) was retrieved after spending 69 months in low Earth orbit (LEO). LDEF carried a remarkable variety of mechanical, electrical, thermal, and optical systems, subsystems, and components. The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long duration exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. Discussed here is the status of the LDEF Systems SIG investigation through the end of 1991.

  1. A Model System to Investigate the Effect of BRCA1 and/or p53 Inactivation in the Ovarian Stroma on Growth and Transformation Potential of the Ovarian Epithelium

    National Research Council Canada - National Science Library

    Connolly, Denise

    2008-01-01

    ...) molecules that promotes carcinoma progression. We are investigating the effects of loss of function of BRCAl and Trp53 in the stroma on the growth and neoplastic transformation of epithelial cells using 2-D and 3-D in vitro culture models...

  2. Investigation of air cleaning system response to accident conditions

    International Nuclear Information System (INIS)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported

  3. Experimental investigation of system effects in stressed-skin elements

    DEFF Research Database (Denmark)

    Dela Stang, B.; Isaksson, T.; Hansson, M.

    What kind of behaviour can be expected from stressed-skin elements at failure? To answer this question was a primary objective of the experimental investigation presented in this report. Systems of 3 roof units, each made of 5 parallel beams, have been tested for load-carrying capacity...... issue in studies of system effects....

  4. System Convergence in Transport Modelling

    DEFF Research Database (Denmark)

    Rich, Jeppe; Nielsen, Otto Anker; Cantarella, Guilio E.

    2010-01-01

    A fundamental premise of most applied transport models is the existence and uniqueness of an equilibrium solution that balances demand x(t) and supply t(x). The demand consists of the people that travel in the transport system and on the defined network, whereas the supply consists of the resulting...... level-of-service attributes (e.g., travel time and cost) offered to travellers. An important source of complexity is the congestion, which causes increasing demand to affect travel time in a non-linear way. Transport models most often involve separate models for traffic assignment and demand modelling...

  5. Theoretical Investigation into Spectral Coexistence of CDMA and TDMA Systems

    Directory of Open Access Journals (Sweden)

    A.M. Abbosh

    2008-12-01

    Full Text Available The scarcity of available radio spectrum presently limits the extension of modern multimedia systems. This paper presents a theoretical investigation into the possibility of using a frequency overlay of a narrowband Code Division Multiple Access (CDMA System and a Time Division Multiple Access (TDMA System to provide a greater spectral efficiency. This paper shows that under certain conditions the two systems can operate in the same frequency band and in the same area with a considerable improvement in the overall capacity of the whole system.

  6. Integrating Building Information Modeling and Augmented Reality to Improve Investigation of Historical Buildings

    Directory of Open Access Journals (Sweden)

    Francesco Chionna

    2015-12-01

    Full Text Available This paper describes an experimental system to support investigation of historical buildings using Building Information Modeling (BIM and Augmented Reality (AR. The system requires the use of an off-line software to build the BIM representation and defines a method to integrate diagnostic data into BIM. The system offers access to such information during site investigation using AR glasses supported by marker and marker-less technologies. The main innovation is the possibility to contextualize through AR not only existing BIM properties but also results from non-invasive tools. User evaluations show how the use of the system may enhance the perception of engineers during the investigation process.

  7. Investigation of the stability of melt flow in gating systems

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Larsen, Per

    2011-01-01

    Melt flow in four different gating systems designed for production of brake discs was analysed experimentally and by numerical modelling. In the experiments moulds were fitted with glass fronts and melt flow was recorded on video. The video recordings were compared with modelling of melt flow in ...

  8. Multilevel Flow Modeling of Domestic Heating Systems

    DEFF Research Database (Denmark)

    Hu, Junjie; Lind, Morten; You, Shi

    2012-01-01

    of complementing this reasoning methodology. Domestic heating systems, as the main resource to meet the thermal requirements of end-users, have different implementations in Europe in order to achieve various degrees of controllability and heating efficiencies. As all the heating systems serve the same basic needs...... i.e. supplying and transferring thermal energy, it is off interest to use MFM to investigate similarities and differences between different implementations. In this paper, three typical domestic European heating systems, which differ from each other in the number of temperature sensors and auxiliary...... components e.g. storage tanks, are modeled using the MFM methodology. Both the goals and functions of material and energy processes and the control functions of the heating systems are represented in the MFM models. It is found that varying the physical system setup results in only little differences among...

  9. CTBT Integrated Verification System Evaluation Model

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.; Bunting, M.L.; Payne, A.C. Jr.

    1997-10-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

  10. Executive Information Systems' Multidimensional Models

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it into information for the organization. These technologies are known as Business Intelligence Tools. But in order to build analytic reports for Executive Information Systems (EIS in an organization we need to design a multidimensional model based on the business model from the organization. This paper presents some multidimensional models that can be used in EIS development and propose a new model that is suitable for strategic business requests.

  11. Compact turnkey focussing neutron guide system for inelastic scattering investigations

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, G., E-mail: g.brandl@fz-juelich.de [Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, 85748 Garching, Germany and Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum - MLZ, Forschungszentrum Jülich GmbH, 85748 Garching (Germany); Georgii, R. [Heinz Maier-Leibnitz Zentrum (MLZ) and Physik Department E21, Technische Universität München, 85748 Garching (Germany); Dunsiger, S. R. [Physik Department E21, Technische Universität München, 85748 Garching, Germany and Center for Emergent Materials, Ohio State University, Columbus, Ohio 43210-1117 (United States); Tsurkan, V. [Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86159 Augsburg, Germany and Institute of Applied Physics, Academy of Sciences of Moldova, MD 2028 Chisinau, Republic of Moldova (Germany); Loidl, A. [Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86159 Augsburg (Germany); Adams, T.; Pfleiderer, C.; Böni, P. [Physik Department E21, Technische Universität München, 85748 Garching (Germany)

    2015-12-21

    We demonstrate the performance of a compact neutron guide module which boosts the intensity in inelastic neutron scattering experiments by approximately a factor of 40. The module consists of two housings containing truly curved elliptic focussing guide elements, positioned before and after the sample. The advantage of the module lies in the ease with which it may be reproducibly mounted on a spectrometer within a few hours, on the same timescale as conventional sample environments. It is particularly well suited for samples with a volume of a few mm{sup 3}, thus enabling the investigation of materials which to date would have been considered prohibitively small or samples exposed to extreme environments, where there are space constraints. We benchmark the excellent performance of the module by measurements of the structural and magnetic excitations in single crystals of model systems. In particular, we report the phonon dispersion in the simple element lead. We also determine the magnon dispersion in the spinel ZnCr{sub 2}Se{sub 4} (V = 12.5 mm{sup 3}), where strong magnetic diffuse scattering at low temperatures evolves into distinct helical order.

  12. Investigation on energy efficient sensor node placement in railway systems

    Directory of Open Access Journals (Sweden)

    Ayona Philipose

    2016-06-01

    Full Text Available Recently wireless sensor network (WSN has been widely used for monitoring railway tracks and rail tunnels. The key requirement in the design of such WSN is to minimize the energy consumption so as to maximize the network lifetime. This paper includes the performance of an improved medium access control (MAC protocol, namely, time adaptive-bit map assisted (TA-BMA protocol, for the purpose of communication between the sensors placed in a railway wagon. The train is considered to be moving at a constant speed, and the sensor nodes are stationary with respect to the motion of train. The effect of mobility on the proposed MAC protocol is determined using genetic algorithm (GA, and the observed increase in energy consumption on considering mobility is 18.51%. Performance analysis of the system model is carried out using QualNet (ver. 7.1, and the energy consumption in transmit mode, receive mode, percentage of time in sleep mode, end-to-end delay and throughput are investigated.

  13. Numerical Investigation of a Moisture Evaporation Model in Building Materials

    CERN Document Server

    Amirkhanov, I V; Pavlish, M; Puzynina, T P; Puzynin, I V; Sarhadov, I

    2005-01-01

    The properties of a model of moisture evaporation in a porous building material of a rectangular form proposed in [1] are investigated. Algorithms of solving a nonlinear diffusion equation with initial and boundary conditions simulating the dynamic distribution of moisture concentration, calculation of coefficients of a polynomial describing transport of moisture with usage of experimental measurement of moisture concentration in a sample are developed and investigated. Research on the properties of the model is carried out depending on the degree of the polynomial, a set of its coefficients, and the quantity of the used experimental data.

  14. Geological Site Descriptive Model. A strategy for the model development during site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Munier, Raymond; Stenberg, Leif [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Stanfors, Roy [Roy Stanfors Consulting, Lund (Sweden); Milnes, Allan Geoffrey [GEA Consulting, Uppsala (Sweden); Hermanson, Jan [Golder Associates, Stockholm (Sweden); Triumf, Carl-Axel [Geovista, Luleaa (Sweden)

    2003-04-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is at present conducting site investigations as a preliminary to building an underground nuclear waste disposal facility in Sweden. This report presents a methodology for constructing, visualising and presenting 3-dimensional geological models, based on data from the site investigations. The methodology integrates with the overall work-flow of the site investigations, from the collection of raw data to the complete site description, as proposed in several earlier technical reports. Further, it is specifically designed for interaction with SICADA - SKB's Site Characterisation Database - and RVS - SKB's Rock Visualisation System. This report is one in a series of strategy documents intended to demonstrate how modelling is to be performed within each discipline. However, it also has a wider purpose, since the geological site descriptive model provides the basic geometrical framework for all the other disciplines. Hence, the wider aim is to present a practical and clear methodology for the analysis and interpretation of input data for use in the construction of the geology-based 3D geometrical model. In addition to the various aspects of modelling described above, the methodology presented here should therefore also provide: guidelines and directives on how systematic interpretation and integration of geo-scientific data from the different investigation methods should be carried out; guidelines on how different geometries should be created in the geological models; guidelines on how the assignment of parameters to the different geological units in RVS should be accomplished; guidelines on the handling of uncertainty at different points in the interpretation process. In addition, it should clarify the relation between the geological model and other models used in the processes of site characterisation, repository layout and safety analysis. In particular, integration and transparency should be

  15. System Code Models and Capabilities

    International Nuclear Information System (INIS)

    Bestion, D.

    2008-01-01

    System thermalhydraulic codes such as RELAP, TRACE, CATHARE or ATHLET are now commonly used for reactor transient simulations. The whole methodology of code development is described including the derivation of the system of equations, the analysis of experimental data to obtain closure relation and the validation process. The characteristics of the models are briefly presented starting with the basic assumptions, the system of equations and the derivation of closure relationships. An extensive work was devoted during the last three decades to the improvement and validation of these models, which resulted in some homogenisation of the different codes although separately developed. The so called two-fluid model is the common basis of these codes and it is shown how it can describe both thermal and mechanical nonequilibrium. A review of some important physical models allows to illustrate the main capabilities and limitations of system codes. Attention is drawn on the role of flow regime maps, on the various methods for developing closure laws, on the role of interfacial area and turbulence on interfacial and wall transfers. More details are given for interfacial friction laws and their relation with drift flux models. Prediction of chocked flow and CFFL is also addressed. Based on some limitations of the present generation of codes, perspectives for future are drawn.

  16. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...... insight. It is based on a sensitivity approach that is useful for choice of model structure, for experiment design, and for accuracy verification. The method is implemented in the Matlab toolkit Senstools. The method and the presentation have been developed with generally preferred learning styles in mind...

  17. Innovative technology summary report: compact subsurface soil investigation system

    International Nuclear Information System (INIS)

    1998-01-01

    The compact subsurface soil investigation system is a mobile soil sampler used to obtain soil samples, including from below concrete floors, such as under fuel storage basins. If soils under buildings can be sampled and analyzed to document that the soil is not contaminated and thus can remain in place, the concrete structure over it may also be left in place or only partially removed. Taking soil samples through a concrete floor, often in inaccessible or congested locations, required rugged, portable equipment, such as the improved technology tested, the Geoprobe Model 540M soil sampler that is mounted on a hand cart. The traditional (baseline) technology used a comparable probe mounted on a full-size, 1-ton capacity, diesel-powered truck. The truck was not easily able to access all areas, because of its greater size and weight. In two sample holes from below the fuel storage basin at C-Reactor, the Geoprobe Model 540M was able to penetrate to the full sampling target depth of 3.3 m (10 ft). In the other three locations the sampler was stopped at lesser depths because of large stones. The Geoprobe 540M reduced schedule time and reduced costs by approximately 50% versus the baseline technology. For sampling at a congested fuel storage basin at five locations, the improved technology cost $7,300, whereas the baseline technology would have cost $13,000. As an extension of this demonstration, cost savings and schedule acceleration can be expected to increase commensurate with structure complexity/congestion and the number of samples required

  18. A Comprehensive and Harmonized Digital Forensic Investigation Process Model.

    Science.gov (United States)

    Valjarevic, Aleksandar; Venter, Hein S

    2015-11-01

    Performing a digital forensic investigation (DFI) requires a standardized and formalized process. There is currently neither an international standard nor does a global, harmonized DFI process (DFIP) exist. The authors studied existing state-of-the-art DFIP models and concluded that there are significant disparities pertaining to the number of processes, the scope, the hierarchical levels, and concepts applied. This paper proposes a comprehensive model that harmonizes existing models. An effort was made to incorporate all types of processes proposed by the existing models, including those aimed at achieving digital forensic readiness. The authors introduce a novel class of processes called concurrent processes. This is a novel contribution that should, together with the rest of the model, enable more efficient and effective DFI, while ensuring admissibility of digital evidence. Ultimately, the proposed model is intended to be used for different types of DFI and should lead to standardization. © 2015 American Academy of Forensic Sciences.

  19. Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

    Science.gov (United States)

    Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

    2017-02-01

    NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

  20. Compositional Modeling of Biological Systems

    OpenAIRE

    Zámborszky, Judit

    2010-01-01

    Molecular interactions are wired in a fascinating way resulting in complex behavior of bio-logical systems. Theoretical modeling provides us a useful framework for understanding the dynamics and the function of such networks. The complexity of the biological systems calls for conceptual tools that manage the combinatorial explosion of the set of possible interac-tions. A suitable conceptual tool to attack complexity is compositionality, already success-fully used in the process algebra field ...

  1. Similarity conditions for investigations of hydraulic-thermal tidal models

    International Nuclear Information System (INIS)

    Fluegge, G.; Schwarze, H.

    1975-01-01

    With the construction of nuclear power plants near German tidal estuaries in mind, investigations of mixing and spreading processes which occur during the discharge of heated cooling water in tidal waters were carried out in hydraulic-thermal tidal models of the Lower Weser and Lower Elbe by the Franzius Institute for hydraulic and coastal engineering of the Technical University Hannover. This contribution discusses in detail the problems met and the experience gained in constructing and operating these models. (orig./TK) [de

  2. A Harmonized Process Model for Digital Forensic Investigation Readiness

    OpenAIRE

    Valjarevic , Aleksandar; Venter , Hein

    2013-01-01

    Part 2: FORENSIC MODELS; International audience; Digital forensic readiness enables an organization to prepare itself to perform digital forensic investigations in an efficient and effective manner. The benefits include enhancing the admissibility of digital evidence, better utilization of resources and greater incident awareness. However, a harmonized process model for digital forensic readiness does not currently exist and, thus, there is a lack of effective and standardized implementations...

  3. Investigation of 160 Gbit/s optical communication systems

    DEFF Research Database (Denmark)

    Xu, Zhenbo

    2006-01-01

    In this thesis 160 Gbit/s per-channel transmission systems are investigated in the form of both single channel systems and WDM systems. The aim of the research is to identify the longest possible transmission distance, employing Raman amplification and to study advanced modulation formats. Numerous...... a transmission system standpoint. The first section focuses on the discrete Raman amplification with estimation of system performance using four kinds of Raman pumping schemes. An optimal transmission distance of 1800 km is predicted. Moreover, signal pulse width, dispersion and effective core area of fibers...... are discussed with respect to system performance. In the following section three schemes with distributed Raman amplification are discussed. The system performance is improved reaching a transmission distance of 2500 km. The optimal signal power evolution and span input power for the three pumping schemes...

  4. Investigations of radioactive contamination of 'underlying surface - atmosphere' system

    International Nuclear Information System (INIS)

    Osintsev, A.Yu.; Panin, M.S.; Artem'ev, O.I.; Gaziev, Ya.I.

    2008-01-01

    In article the results of carried out field investigations of radionuclide compositions and dispersed characteristics of anthropogenic dust lifting products and organized on radioactive 'spot' on the Semipalatinsk Test Site fires are presented. Investigations were made for the purpose of parameters refinement and improvement of physico-mathematical models of air environmental pollution with aerosuspensions and aerosols from different sources them intensive entrance in the atmosphere

  5. Parametric Modeling for Fluid Systems

    Science.gov (United States)

    Pizarro, Yaritzmar Rosario; Martinez, Jonathan

    2013-01-01

    Fluid Systems involves different projects that require parametric modeling, which is a model that maintains consistent relationships between elements as is manipulated. One of these projects is the Neo Liquid Propellant Testbed, which is part of Rocket U. As part of Rocket U (Rocket University), engineers at NASA's Kennedy Space Center in Florida have the opportunity to develop critical flight skills as they design, build and launch high-powered rockets. To build the Neo testbed; hardware from the Space Shuttle Program was repurposed. Modeling for Neo, included: fittings, valves, frames and tubing, between others. These models help in the review process, to make sure regulations are being followed. Another fluid systems project that required modeling is Plant Habitat's TCUI test project. Plant Habitat is a plan to develop a large growth chamber to learn the effects of long-duration microgravity exposure to plants in space. Work for this project included the design and modeling of a duct vent for flow test. Parametric Modeling for these projects was done using Creo Parametric 2.0.

  6. Modeling and simulation of porous journal bearings in multibody systems

    OpenAIRE

    Buuren, Sietze van

    2013-01-01

    A specific cost-efficient type of plain journal bearing is the porous journal bearing, which possesses a pervious bush that serves as a lubricant reservoir. The current work is concerned with modeling porous journal bearings in multibody systems, for which dynamical models are needed to investigate the bearing’s behavior. Such porous journal bearing models as well as models of elementary rotor-bearing systems including these, were developed and investigated during the course for this work.

  7. Investigation of wax precipitation in crude oil: Experimental and modeling

    Directory of Open Access Journals (Sweden)

    Taraneh Jafari Behbahani

    2015-09-01

    Full Text Available In this work, a series of experiments were carried to investigation of rheological behavior of crude oil using waxy crude oil sample in the absence/presence of flow improver such as ethylene-vinyl acetate copolymer. The rheological data covered the temperature range of 5–30 °C. The results indicated that the performance of flow improver was dependent on its molecular weight. Addition of small quantities of flow improver, can improve viscosity and pour point of crude oil. Also, an Artificial Neural Network (ANN model using Multi-Layer Perceptron (MLP topology has been developed to account wax appearance temperature and the amount of precipitated wax and the model was verified using experimental data given in this work and reported in the literature. In order to compare the performance of the proposed model based on Artificial Neural Network, the wax precipitation experimental data at different temperatures were predicted using solid solution model and multi-solid phase model. The results showed that the developed model based on Artificial Neural Network can predict more accurately the wax precipitation experimental data in comparison to the previous models such as solid solution and multi-solid phase model with AADs less than 0.5%. Furthermore, the number of parameters required for the Artificial Neural Network (ANN model is less than the studied thermodynamic models.

  8. Model checking embedded system designs

    NARCIS (Netherlands)

    Brinksma, Hendrik; Mader, Angelika H.

    2002-01-01

    Model checking has established itself as a successful tool supported technique for the verification and debugging of various hardware and software systems [16]. Not only in academia, but also by industry this technique is increasingly being regarded as a promising and practical proposition,

  9. GENERIC model for multiphase systems

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2010-01-01

    GENERIC is a nonequilibrium thermodynamic formalism in which the dynamic behavior of a system is described by a single compact equation involving two types of brackets: a Poisson bracket and a dissipative bracket. This formalism has proved to be a very powerful instrument to model the dynamic

  10. An extensible analysable system model

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, Rene Rydhof

    2008-01-01

    Analysing real-world systems for vulnerabilities with respect to security and safety threats is a difficult undertaking, not least due to a lack of availability of formalisations for those systems. While both formalisations and analyses can be found for artificial systems such as software......, this does not hold for real physical systems. Approaches such as threat modelling try to target the formalisation of the real-world domain, but still are far from the rigid techniques available in security research. Many currently available approaches to assurance of critical infrastructure security...... are based on (quite successful) ad-hoc techniques. We believe they can be significantly improved beyond the state-of-the-art by pairing them with static analyses techniques. In this paper we present an approach to both formalising those real-world systems, as well as providing an underlying semantics, which...

  11. Common cause failure investigations using the European Reliability Data System

    International Nuclear Information System (INIS)

    Games, A.M.; Breewood, M.; Amendola, A.; Keller, A.Z.

    1984-01-01

    The European Reliability Data System (ERDS) has provided data for use in investigations into common cause failures (CCFs) in nuclear power plants. These investigations have been made on two levels, at a system and inter-system level. Data have been used from the Component Event Data Bank and from the Licensee Event Report Files, both part of the ERDS. The two studies required different methodologies although both commenced with a temporal sorting procedure for the failure events. The studies demonstrated that different types of common cause failure necessitate different search algorithms, and thus a data search must be closely related to an appropriate CCF classification system, which in the first instance would not be based on causes of failure. (author)

  12. Investigation of some approximation used in promptly emitted particle models

    International Nuclear Information System (INIS)

    Leray, S.; La Rana, G.; Lucas, R.; Ngo, C.; Barranco, M.; Pi, M.; Vinas, X.

    1984-01-01

    We investigate three effects which can be taken into account in a model for promptly emitted particles: the Pauli blocking, the velocity of the window separating the two ions with respect to each of the fragments and the spatial extension of the window

  13. The development of a theoretical model to investigate factors

    African Journals Online (AJOL)

    user

    ISSN 0378-5254 Journal of Family Ecology and Consumer Sciences, Vol 41, 2013. The development of a theoretical model to investigate factors associated with environmentally significant choice behaviour in the South ..... attitudes toward the behaviour, social pressure or subjective norms surrounding the behaviour.

  14. Infectious disease modeling a hybrid system approach

    CERN Document Server

    Liu, Xinzhi

    2017-01-01

    This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

  15. Investigating benefits realisation process for enterprise resource planning systems

    OpenAIRE

    Badewi, Amgad

    2016-01-01

    This research aims to investigate the benefit realisation process for ERP systems so as to develop a benefit realization road map whereby organisations can realize the maximum potential of their ERP systems. This research covers two areas: mechanism of implementation and the destination to change (i.e. road map). It has been found that project management and benefits management approaches are necessary for recouping benefits from investing in Information Technologies (IT) pr...

  16. Solar thermally driven cooling systems: Some investigation results and perspectives

    International Nuclear Information System (INIS)

    Ajib, Salman; Günther, Wolfgang

    2013-01-01

    Highlights: ► Two types of solar thermally driven absorption refrigeration machines (ARMs) have been investigated. ► We investigated the influence of the operating conditions on the effectiveness of the ARMs. ► The influence of the flow rate of the work solution on the effectiveness of the ARMs has been tested. ► Two laboratory test plants have been built and tested under different operating conditions. - Abstract: A big increase in the number of solar thermal cooling installations and research efforts could be seen over the last years worldwide. Especially the producers of solar thermal collectors and systems have been looking for thermal chillers in the small capacity range to provide air conditioning for one or two family houses. Furthermore, many developments aim to increase the efficiency of the system and to decrease the specific costs of the produced refrigeration capacity. The growth in the use of solar thermal cooling systems amounted about 860% from 52 units in 2004 to 450 units in 2009 [1]. This tendency is expected to be continuously in the next years. The practical examinations on solar thermally driven absorption machines with refrigeration capacity of 15, 10 and 5 kW have shown that this technology has a good chance to be standardized and to replace partly the conventional one. These systems can save more primary energy at high fraction of solar thermally driving by suitable control and regulation of the system. The investing costs still higher as the conventional one, however, the operating costs are less than the conventional one. The Coefficient of Performance (COP) depends on the kind of the system, work temperatures and conditions as well as the refrigeration capacity of the systems. It lies between 0.4 and 1.2. In the framework of the research on this field, we built, tested and measured two prototypes. After measuring the first prototype, the chillers were redesigned to reduce internal heat losses and make the heat and mass transfer

  17. Systems modeling for laser IFE

    Science.gov (United States)

    Meier, W. R.; Raffray, A. R.; Sviatoslavsky, I. N.

    2006-06-01

    A systems model of a laser-driven IFE power plant is being developed to assist in design trade-offs and optimization. The focus to date has been on modeling the fusion chamber, blanket and power conversion system. A self-consistent model has been developed to determine key chamber and thermal cycle parameters (e.g., chamber radius, structure and coolant temperatures, cycle efficiency, etc.) as a function of the target yield and pulse repetition rate. Temperature constraints on the tungsten armor, ferritic steel wall, and structure/coolant interface are included in evaluating the potential design space. Results are presented for a lithium cooled first wall coupled with a Brayton power cycle. LLNL work performed under the auspices of the US Department of Energy by the University of California LLNL under Contract W-7405-Eng-48.

  18. Software Engineering Support of the Third Round of Scientific Grand Challenge Investigations: An Earth Modeling System Software Framework Strawman Design that Integrates Cactus and UCLA/UCB Distributed Data Broker

    Science.gov (United States)

    Talbot, Bryan; Zhou, Shu-Jia; Higgins, Glenn

    2002-01-01

    One of the most significant challenges in large-scale climate modeling, as well as in high-performance computing in other scientific fields, is that of effectively integrating many software models from multiple contributors. A software framework facilitates the integration task. both in the development and runtime stages of the simulation. Effective software frameworks reduce the programming burden for the investigators, freeing them to focus more on the science and less on the parallel communication implementation, while maintaining high performance across numerous supercomputer and workstation architectures. This document proposes a strawman framework design for the climate community based on the integration of Cactus, from the relativistic physics community, and UCLA/UCB Distributed Data Broker (DDB) from the climate community. This design is the result of an extensive survey of climate models and frameworks in the climate community as well as frameworks from many other scientific communities. The design addresses fundamental development and runtime needs using Cactus, a framework with interfaces for FORTRAN and C-based languages, and high-performance model communication needs using DDB. This document also specifically explores object-oriented design issues in the context of climate modeling as well as climate modeling issues in terms of object-oriented design.

  19. Investigation of RADTRAN Stop Model input parameters for truck stops

    International Nuclear Information System (INIS)

    Griego, N.R.; Smith, J.D.; Neuhauser, K.S.

    1996-01-01

    RADTRAN is a computer code for estimating the risks and consequences as transport of radioactive materials (RAM). RADTRAN was developed and is maintained by Sandia National Laboratories for the US Department of Energy (DOE). For incident-free transportation, the dose to persons exposed while the shipment is stopped is frequently a major percentage of the overall dose. This dose is referred to as Stop Dose and is calculated by the Stop Model. Because stop dose is a significant portion of the overall dose associated with RAM transport, the values used as input for the Stop Model are important. Therefore, an investigation of typical values for RADTRAN Stop Parameters for truck stops was performed. The resulting data from these investigations were analyzed to provide mean values, standard deviations, and histograms. Hence, the mean values can be used when an analyst does not have a basis for selecting other input values for the Stop Model. In addition, the histograms and their characteristics can be used to guide statistical sampling techniques to measure sensitivity of the RADTRAN calculated Stop Dose to the uncertainties in the stop model input parameters. This paper discusses the details and presents the results of the investigation of stop model input parameters at truck stops

  20. Combining experimental observation and modelling in investigating feedback and emotions in repeated selection tasks

    NARCIS (Netherlands)

    Fischer, A.R.H.; Blommaert, F.J.J.; Midden, C.J.H.

    2005-01-01

    People seem to learn tasks even without formal training. This can be modelled as the outcome of a feedback system that accumulates experience. In this paper we investigate such a feedback system, following an iterative research approach. A feedback loop is specified that is detailed using

  1. Systems for Teaching Complex Texts: A Proof-of-Concept Investigation

    Science.gov (United States)

    Fisher, Douglas; Frey, Nancy

    2016-01-01

    In this article we investigate the systems that need to be in place for students to learn from increasingly complex texts. Our concept, drawn from past research, includes clear learning targets, teacher modeling, collaborative conversations, close reading, small group reading, and wide reading. Using a "proof of concept" model, we follow…

  2. Cotangent Models for Integrable Systems

    Science.gov (United States)

    Kiesenhofer, Anna; Miranda, Eva

    2017-03-01

    We associate cotangent models to a neighbourhood of a Liouville torus in symplectic and Poisson manifolds focusing on b-Poisson/ b-symplectic manifolds. The semilocal equivalence with such models uses the corresponding action-angle theorems in these settings: the theorem of Liouville-Mineur-Arnold for symplectic manifolds and an action-angle theorem for regular Liouville tori in Poisson manifolds (Laurent- Gengoux et al., IntMath Res Notices IMRN 8: 1839-1869, 2011). Our models comprise regular Liouville tori of Poisson manifolds but also consider the Liouville tori on the singular locus of a b-Poisson manifold. For this latter class of Poisson structures we define a twisted cotangent model. The equivalence with this twisted cotangent model is given by an action-angle theorem recently proved by the authors and Scott (Math. Pures Appl. (9) 105(1):66-85, 2016). This viewpoint of cotangent models provides a new machinery to construct examples of integrable systems, which are especially valuable in the b-symplectic case where not many sources of examples are known. At the end of the paper we introduce non-degenerate singularities as lifted cotangent models on b-symplectic manifolds and discuss some generalizations of these models to general Poisson manifolds.

  3. Graph modeling systems and methods

    Science.gov (United States)

    Neergaard, Mike

    2015-10-13

    An apparatus and a method for vulnerability and reliability modeling are provided. The method generally includes constructing a graph model of a physical network using a computer, the graph model including a plurality of terminating vertices to represent nodes in the physical network, a plurality of edges to represent transmission paths in the physical network, and a non-terminating vertex to represent a non-nodal vulnerability along a transmission path in the physical network. The method additionally includes evaluating the vulnerability and reliability of the physical network using the constructed graph model, wherein the vulnerability and reliability evaluation includes a determination of whether each terminating and non-terminating vertex represents a critical point of failure. The method can be utilized to evaluate wide variety of networks, including power grid infrastructures, communication network topologies, and fluid distribution systems.

  4. An investigation on the deployments of major computer system ...

    African Journals Online (AJOL)

    This paper investigated the capabilities and limitations of major operating systems with reference to issues of usability, stability, availability, portability, security, flexibility and cost effectiveness; with other attendant inherent and external considerations, like, no licensing, activation, robustness, high scalability and GUI ...

  5. Collection and valuation of numerical models with the aim to investigate the impact of aircraft emissions

    International Nuclear Information System (INIS)

    Dameris, M.

    1993-01-01

    Numerical models which are used to simulate the dynamics and chemistry of the Earth atmosphere are an important expedient to improve the knowledge of atmospheric processes. With such models it is possible to investigate single effects separately and to estimate their meaning for the whole system. It is possible to make sensitivity studies as well as calculations of different scenarios. This paper aims to describe different models which are available in the present time and which can be used for investigations dealing with the impact of aircraft emission on the Earth climate. Actual deficits of the modelling of atmospheric processes are discussed and the subsequent conclusions are presented. (orig.) 49 refs [de

  6. Qualitative models for space system engineering

    Science.gov (United States)

    Forbus, Kenneth D.

    1990-01-01

    The objectives of this project were: (1) to investigate the implications of qualitative modeling techniques for problems arising in the monitoring, diagnosis, and design of Space Station subsystems and procedures; (2) to identify the issues involved in using qualitative models to enhance and automate engineering functions. These issues include representing operational criteria, fault models, alternate ontologies, and modeling continuous signals at a functional level of description; and (3) to develop a prototype collection of qualitative models for fluid and thermal systems commonly found in Space Station subsystems. Potential applications of qualitative modeling to space-systems engineering, including the notion of intelligent computer-aided engineering are summarized. Emphasis is given to determining which systems of the proposed Space Station provide the most leverage for study, given the current state of the art. Progress on using qualitative models, including development of the molecular collection ontology for reasoning about fluids, the interaction of qualitative and quantitative knowledge in analyzing thermodynamic cycles, and an experiment on building a natural language interface to qualitative reasoning is reported. Finally, some recommendations are made for future research.

  7. Probabilistic models for feedback systems.

    Energy Technology Data Exchange (ETDEWEB)

    Grace, Matthew D.; Boggs, Paul T.

    2011-02-01

    In previous work, we developed a Bayesian-based methodology to analyze the reliability of hierarchical systems. The output of the procedure is a statistical distribution of the reliability, thus allowing many questions to be answered. The principal advantage of the approach is that along with an estimate of the reliability, we also can provide statements of confidence in the results. The model is quite general in that it allows general representations of all of the distributions involved, it incorporates prior knowledge into the models, it allows errors in the 'engineered' nodes of a system to be determined by the data, and leads to the ability to determine optimal testing strategies. In this report, we provide the preliminary steps necessary to extend this approach to systems with feedback. Feedback is an essential component of 'complexity' and provides interesting challenges in modeling the time-dependent action of a feedback loop. We provide a mechanism for doing this and analyze a simple case. We then consider some extensions to more interesting examples with local control affecting the entire system. Finally, a discussion of the status of the research is also included.

  8. Stochastic Modelling of Hydrologic Systems

    DEFF Research Database (Denmark)

    Jonsdottir, Harpa

    2007-01-01

    In this PhD project several stochastic modelling methods are studied and applied on various subjects in hydrology. The research was prepared at Informatics and Mathematical Modelling at the Technical University of Denmark. The thesis is divided into two parts. The first part contains an introduct......In this PhD project several stochastic modelling methods are studied and applied on various subjects in hydrology. The research was prepared at Informatics and Mathematical Modelling at the Technical University of Denmark. The thesis is divided into two parts. The first part contains...... an introduction and an overview of the papers published. Then an introduction to basic concepts in hydrology along with a description of hydrological data is given. Finally an introduction to stochastic modelling is given. The second part contains the research papers. In the research papers the stochastic methods...... are described, as at the time of publication these methods represent new contribution to hydrology. The second part also contains additional description of software used and a brief introduction to stiff systems. The system in one of the papers is stiff....

  9. Investigating the performance of directional boundary layer model through staged modeling method

    Science.gov (United States)

    Jeong, Moon-Gyu; Lee, Won-Chan; Yang, Seung-Hune; Jang, Sung-Hoon; Shim, Seong-Bo; Kim, Young-Chang; Suh, Chun-Suk; Choi, Seong-Woon; Kim, Young-Hee

    2011-04-01

    Generally speaking, the models used in the optical proximity effect correction (OPC) can be divided into three parts, mask part, optic part, and resist part. For the excellent quality of the OPC model, each part has to be described by the first principles. However, OPC model can't take the all of the principles since it should cover the full chip level calculation during the correction. Moreover, the calculation has to be done iteratively during the correction until the cost function we want to minimize converges. Normally the optic part in OPC model is described with the sum of coherent system (SOCS[1]) method. Thanks to this method we can calculate the aerial image so fast without the significant loss of accuracy. As for the resist part, the first principle is too complex to implement in detail, so it is normally expressed in a simple way, such as the approximation of the first principles, and the linear combinations of factors which is highly correlated with the chemistries in the resist. The quality of this kind of the resist model depends on how well we train the model through fitting to the empirical data. The most popular way of making the mask function is based on the Kirchhoff's thin mask approximation. This method works well when the feature size on the mask is sufficiently large, but as the line width of the semiconductor circuit becomes smaller, this method causes significant error due to the mask topography effect. To consider the mask topography effect accurately, we have to use rigorous methods of calculating the mask function, such as finite difference time domain (FDTD[2]) and rigorous coupled-wave analysis (RCWA[3]). But these methods are too time-consuming to be used as a part of the OPC model. Until now many alternatives have been suggested as the efficient way of considering the mask topography effect. Among them we focused on the boundary layer model (BLM) in this paper. We mainly investigated the way of optimization of the parameters for the

  10. System Identification Theory Approach to Cohesive Sediment Transport Modelling

    OpenAIRE

    CHEN, HUIXIN

    1997-01-01

    Two aspects of the modelling sediment transport are investigated. One is the univariate time series modelling the current velocity dynamics. The other is the multivariate time series modelling the suspended sediment concentration dynamics. Cohesive sediment dynamics and numerical sediment transport model are reviewed and investigated. The system identification theory and time series analysis method are developed and applied to set up the time series model for current velocity a...

  11. Investigation of Zircaloy-2 oxidation model for SFP accident analysis

    Science.gov (United States)

    Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro; Kondo, Keietsu; Nakashima, Kazuo; Kanazawa, Toru; Tojo, Masayuki

    2017-05-01

    The authors previously conducted thermogravimetric analyses on Zircaloy-2 in air. By using the thermogravimetric data, an oxidation model was constructed in this study so that it can be applied for the modeling of cladding degradation in spent fuel pool (SFP) severe accident condition. For its validation, oxidation tests of long cladding tube were conducted, and computational fluid dynamics analyses using the constructed oxidation model were proceeded to simulate the experiments. In the oxidation tests, high temperature thermal gradient along the cladding axis was applied and air flow rates in testing chamber were controlled to simulate hypothetical SFP accidents. The analytical outputs successfully reproduced the growth of oxide film and porous oxide layer on the claddings in oxidation tests, and validity of the oxidation model was proved. Influence of air flow rate for the oxidation behavior was thought negligible in the conditions investigated in this study.

  12. Discrete modelling of drapery systems

    Science.gov (United States)

    Thoeni, Klaus; Giacomini, Anna

    2016-04-01

    Drapery systems are an efficient and cost-effective measure in preventing and controlling rockfall hazards on rock slopes. The simplest form consists of a row of ground anchors along the top of the slope connected to a horizontal support cable from which a wire mesh is suspended down the face of the slope. Such systems are generally referred to as simple or unsecured draperies (Badger and Duffy 2012). Variations such as secured draperies, where a pattern of ground anchors is incorporated within the field of the mesh, and hybrid systems, where the upper part of an unsecured drapery is elevated to intercept rockfalls originating upslope of the installation, are becoming more and more popular. This work presents a discrete element framework for simulation of unsecured drapery systems and its variations. The numerical model is based on the classical discrete element method (DEM) and implemented into the open-source framework YADE (Šmilauer et al., 2010). The model takes all relevant interactions between block, drapery and slope into account (Thoeni et al., 2014) and was calibrated and validated based on full-scale experiments (Giacomini et al., 2012).The block is modelled as a rigid clump made of spherical particles which allows any shape to be approximated. The drapery is represented by a set of spherical particle with remote interactions. The behaviour of the remote interactions is governed by the constitutive behaviour of the wire and generally corresponds to a piecewise linear stress-strain relation (Thoeni et al., 2013). The same concept is used to model wire ropes. The rock slope is represented by rigid triangular elements where material properties (e.g., normal coefficient of restitution, friction angle) are assigned to each triangle. The capabilities of the developed model to simulate drapery systems and estimate the residual hazard involved with such systems is shown. References Badger, T.C., Duffy, J.D. (2012) Drapery systems. In: Turner, A.K., Schuster R

  13. Investigation of noise sources for digital radiography systems.

    Science.gov (United States)

    Ergun, Lutfi; Olgar, Turan

    2017-06-01

    The performance of digital radiography systems can be evaluated in terms of spatial resolution and noise. Noise plays an important role in the achievable image quality for detecting small and low-contrast structures in digital images created by these systems. Our aim in this study was to investigate the noise sources both in the spatial and frequency domain for three digital radiography systems, one digital fluoroscopy system, and one digital mammography system, and to obtain information about the effective operating dose range of these detectors. Noise evaluation in the spatial domain was done with the relative standard deviation-detector air kerma relationship evaluation method. The characterization of the noise in the spatial domain gives information about the types of noise, but does not give information about the noise power distribution in frequency space. Therefore, noise evaluation in the frequency domain was carried out by noise power spectrum measurement. The observed dominant noise component at lower detector doses was electronic noise for the digital mammography system, whereas structured noise was observed to make up nearly half of the total noise at higher detector doses for one of the digital radiography systems. The structured noise component was increased by use of a grid in these systems, independent of the grid ratio and grid frequency, but this increase was lower for higher grid frequencies. Furthermore, the structured noise coefficient was decreased with gain and offset calibrations. The five systems which we evaluated behaved as a quantum noise limited for clinically used detector doses.

  14. Experimental investigation of elastic mode control on a model of a transport aircraft

    Science.gov (United States)

    Abramovitz, M.; Heimbaugh, R. M.; Nomura, J. K.; Pearson, R. M.; Shirley, W. A.; Stringham, R. H.; Tescher, E. L.; Zoock, I. E.

    1981-01-01

    A 4.5 percent DC-10 derivative flexible model with active controls is fabricated, developed, and tested to investigate the ability to suppress flutter and reduce gust loads with active controlled surfaces. The model is analyzed and tested in both semispan and complete model configuration. Analytical methods are refined and control laws are developed and successfully tested on both versions of the model. A 15 to 25 percent increase in flutter speed due to the active system is demonstrated. The capability of an active control system to significantly reduce wing bending moments due to turbulence is demonstrated. Good correlation is obtained between test and analytical prediction.

  15. Modeling-Enabled Systems Nutritional Immunology

    Directory of Open Access Journals (Sweden)

    Meghna eVerma

    2016-02-01

    Full Text Available This review highlights the fundamental role of nutrition in the maintenance of health, the immune response and disease prevention. Emerging global mechanistic insights in the field of nutritional immunology cannot be gained through reductionist methods alone or by analyzing a single nutrient at a time. We propose to investigate nutritional immunology as a massively interacting system of interconnected multistage and multiscale networks that encompass hidden mechanisms by which nutrition, microbiome, metabolism, genetic predisposition and the immune system interact to delineate health and disease. The review sets an unconventional path to applying complex science methodologies to nutritional immunology research, discovery and development through ‘use cases’ centered around the impact of nutrition on the gut microbiome and immune responses. Our systems nutritional immunology analyses, that include modeling and informatics methodologies in combination with pre-clinical and clinical studies, have the potential to discover emerging systems-wide properties at the interface of the immune system, nutrition, microbiome, and metabolism.

  16. Experimental investigation and modeling of dynamic performance of wave springs

    OpenAIRE

    Tang, N.; Rongong, J.; Lord, C.; Sims, N.

    2016-01-01

    This paper investigates vibration suppression potentials for a novel frictional system - a wave spring.\\ud Two different types of wave springs, crest-to-crest and nested ones, were used in this work. Compared with\\ud nested wave springs, crest-to-crest wave springs have lower damping and a larger range for the linear stiffness\\ud due to a reduced level of contact. Dynamic compressive tests, subject to different static compression levels,\\ud are carried out to investigate the force-displacemen...

  17. A multiscale modeling approach for biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, Alan, E-mail: bowling@uta.edu; Haghshenas-Jaryani, Mahdi, E-mail: mahdi.haghshenasjaryani@mavs.uta.edu [The University of Texas at Arlington, Department of Mechanical and Aerospace Engineering (United States)

    2015-04-15

    This paper presents a new multiscale molecular dynamic model for investigating the effects of external interactions, such as contact and impact, during stepping and docking of motor proteins and other biomolecular systems. The model retains the mass properties ensuring that the result satisfies Newton’s second law. This idea is presented using a simple particle model to facilitate discussion of the rigid body model; however, the particle model does provide insights into particle dynamics at the nanoscale. The resulting three-dimensional model predicts a significant decrease in the effect of the random forces associated with Brownian motion. This conclusion runs contrary to the widely accepted notion that the motor protein’s movements are primarily the result of thermal effects. This work focuses on the mechanical aspects of protein locomotion; the effect ATP hydrolysis is estimated as internal forces acting on the mechanical model. In addition, the proposed model can be numerically integrated in a reasonable amount of time. Herein, the differences between the motion predicted by the old and new modeling approaches are compared using a simplified model of myosin V.

  18. Modelling of stationary bulk hydrogen storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Venter, R.D.; Pucher, G. [Centre for Hydrogen and Electrochemical Studies (CHES), University of Toronto (Canada)

    1997-08-01

    The employment of bulk hydrogen storage systems within industry appears increasingly to be a near-term prospect given the steadily increasing levels of hydrogen production. The current study defines and outlines a cost model through which comparative and informative assessments of different stationary bulk hydrogen storage reservoir types can be made. The reservoir types investigated include: mined salt caverns, depleted natural gas reservoirs and liquid vessels. Using the model, cost of storage for these potential bulk hydrogen containment technologies is estimated and compared in qualitative terms. for similar storage applications. (Author)

  19. Model reduction of parametrized systems

    CERN Document Server

    Ohlberger, Mario; Patera, Anthony; Rozza, Gianluigi; Urban, Karsten

    2017-01-01

    The special volume offers a global guide to new concepts and approaches concerning the following topics: reduced basis methods, proper orthogonal decomposition, proper generalized decomposition, approximation theory related to model reduction, learning theory and compressed sensing, stochastic and high-dimensional problems, system-theoretic methods, nonlinear model reduction, reduction of coupled problems/multiphysics, optimization and optimal control, state estimation and control, reduced order models and domain decomposition methods, Krylov-subspace and interpolatory methods, and applications to real industrial and complex problems. The book represents the state of the art in the development of reduced order methods. It contains contributions from internationally respected experts, guaranteeing a wide range of expertise and topics. Further, it reflects an important effor t, carried out over the last 12 years, to build a growing research community in this field. Though not a textbook, some of the chapters ca...

  20. Investigating ecological speciation in non-model organisms

    DEFF Research Database (Denmark)

    Foote, Andrew David

    2012-01-01

    Background: Studies of ecological speciation tend to focus on a few model biological systems. In contrast, few studies on non-model organisms have been able to infer ecological speciation as the underlying mechanism of evolutionary divergence. Questions: What are the pitfalls in studying ecological...... on killer whale evolutionary ecology in search of any difficulty in demonstrating causal links between variation in phenotype, ecology, and reproductive isolation in this non-model organism. Results: At present, we do not have enough evidence to conclude that adaptive phenotype traits linked to ecological...... variation underlie reproductive isolation between sympatric killer whale types. Perhaps ecological speciation has occurred, but it is hard to prove. We will probably face this outcome whenever we wish to address non-model organisms – species in which it is not easy to apply experimental approaches...

  1. Modeling software systems by domains

    Science.gov (United States)

    Dippolito, Richard; Lee, Kenneth

    1992-01-01

    The Software Architectures Engineering (SAE) Project at the Software Engineering Institute (SEI) has developed engineering modeling techniques that both reduce the complexity of software for domain-specific computer systems and result in systems that are easier to build and maintain. These techniques allow maximum freedom for system developers to apply their domain expertise to software. We have applied these techniques to several types of applications, including training simulators operating in real time, engineering simulators operating in non-real time, and real-time embedded computer systems. Our modeling techniques result in software that mirrors both the complexity of the application and the domain knowledge requirements. We submit that the proper measure of software complexity reflects neither the number of software component units nor the code count, but the locus of and amount of domain knowledge. As a result of using these techniques, domain knowledge is isolated by fields of engineering expertise and removed from the concern of the software engineer. In this paper, we will describe kinds of domain expertise, describe engineering by domains, and provide relevant examples of software developed for simulator applications using the techniques.

  2. Investigation of hydrate formation and transportability in multiphase flow systems

    Science.gov (United States)

    Grasso, Giovanny A.

    The oil and gas industry is moving towards offshore developments in more challenging environments, where evaluating hydrate plugging risks to avoid operational/safety hazards becomes more difficult (Sloan, 2005). Even though mechanistic models for hydrate plug formation have been developed, components for a full comprehensive model are still missing. Prior to this work, research efforts were focused on flowing hydrate particles with relatively little research on hydrate accumulation, leaving hydrate deposition in multiphase flow an unexplored subject. The focus of this thesis was to better understand hydrate deposition as a form of accumu- lation in pipelines. To incorporate the multiphase flow effect, hydrate formation experiments were carried out at varying water cut (WC) from 15 to 100 vol.%, liquid loading (LL) from 50 to 85 vol.%, mixture velocity (vmix) from 0.75 to 3 m/s, for three fluids systems (100 % WC, water in Conroe crude oil emulsions and King Ranch condensate + water) on the ExxonMobil flowloop (4 in. nominal size and 314 ft. long) at Friendswood, TX. For the 100 % WC flowloop tests, hydrate particle distribution transitions beyond a critical hydrate volume concentration, observed values were between 8.2 to 29.4 vol.%, causing a sudden increase in pressure drop (DP). A revised correlation of the transition as a function of Reynolds number and liquid loading was developed. For Conroe emulsions, DP starts increasing at higher hydrate concentrations than King Ranch condensate, many times at 10 vol.%. Experiments with King Ranch show higher relative DP (10 to 25) than Conroe (2 to 10) performed at the same vmix and LL. Cohesive force measurements between cyclopentane hydrate particles were reduced from a value of 3.32 mN/m to 1.26 mN/m when 6 wt.% Conroe was used and to 0.41 mN/m when 5 wt.% Caratinga crude oil was used; similar values were obtained when extracted asphaltenes were used. King Ranch condensate (11 wt.%) did not significantly change the

  3. Metabolic network modeling approaches for investigating the "hungry cancer".

    Science.gov (United States)

    Sharma, Ashwini Kumar; König, Rainer

    2013-08-01

    Metabolism is the functional phenotype of a cell, at a given condition, resulting from an intricate interplay of various regulatory processes. The study of these dynamic metabolic processes and their capabilities help to identify the fundamental properties of living systems. Metabolic deregulation is an emerging hallmark of cancer cells. This deregulation results in rewiring of the metabolic circuitry conferring an exploitative metabolic advantage for the tumor cells which leads to a distinct benefit in survival and lays the basis for unbound progression. Metabolism can be considered as a thermodynamic open-system in which source substrates of high value are being processed through a well established interconnected biochemical conversion system, strictly obeying physiochemical principles, generating useful intermediates and finally resulting in the release of byproducts. Based on this basic principle of an input-output balance, various models have been developed to interrogate metabolism elucidating its underlying functional properties. However, only a few modeling approaches have proved computationally feasible in elucidating the metabolic nature of cancer at a systems level. Besides this, statistical approaches have been set up to identify biochemical pathways being more relevant for specific types of tumor cells. In this review, we are briefly introducing the basic statistical approaches followed by the major modeling concepts. We have put an emphasis on the methods and their applications that have been used to a greater extent in understanding the metabolic remodeling of cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Investigation and simulation of the CAMAC serial system

    International Nuclear Information System (INIS)

    Brehmer, W.

    1976-12-01

    This report consists of a description of the essential attributes of the CAMAC Serial System, and an investigation of the functions included in the Serial Driver. The simulation was used by the ESONE Serial Driver Subgroup to define the basic functions of a Serial Driver. The simulation gives explanations about the efficiency and security of the CAMAC Serial System under error conditions. The simulation uses in the Error Handler the more powerful 'extended analysis' and shows the loss of efficiency and the restrictions if the 'basic analysis' is used. (orig.) [de

  5. Investigating the cores of fossil systems with Chandra

    OpenAIRE

    Bharadwaj, V.; Reiprich, T. H.; Sanders, J. S.; Schellenberger, G.

    2015-01-01

    We investigate the cores of fossil galaxy groups and clusters (`fossil systems') using archival Chandra data for a sample of 17 fossil systems. We determined the cool-core fraction for fossils via three observable diagnostics, the central cooling time, cuspiness, and concentration parameter. We quantified the dynamical state of the fossils by the X-ray peak/brightest cluster galaxy (BCG), and the X-ray peak/emission weighted centre separations. We studied the X-ray emission coincident with th...

  6. CRRIS: a computerized radiological risk-investigation system

    International Nuclear Information System (INIS)

    Baes, C.F. III; Miller, C.W.

    1981-01-01

    The US Environmental Protection Agency (EPA) is responsible for regulating radioactive airborne effluents in the US. A comprehensive, integrated Computerized Radiological Risk Investigation System (CRRIS) is being developed to support EPA's radiation standards development. This modular system consists primarily of five computer codes and their supporting data bases for estimating environmental transport and radiation doses and risks. Health effects are estimated on the basis of a life-table methodology developed by EPA. CRRIS is designed to provide EPA with a reasonable and flexible way of assessing the risk to man associated with radionuclide releases to the atmosphere

  7. Modelling and Experimental Investigation of an Active Damper

    Directory of Open Access Journals (Sweden)

    Rafael Luís Teixeira

    2006-01-01

    Full Text Available This paper presents a validation methodology of the dynamic behavior of an active viscous damper. The damper has two flexible metallic bellows connected to a rigid reservoir filled with fluid. When one of the bellows is connected to a vibrating structure a periodic flow passes through a variable internal orifice and the damping effect is produced. The size of the orifice is adjusted by a controlled linear piezoelectric actuator that positions the conical core into a conical cavity. The device finite element structural model consists of the valve body and its conical core that are assumed rigid and the flexible bellows are represented by two pistons with elastic suspensions. The flow developed inside the damper is modeled considering the fluid-structure interation, using the Lagrangean-Eulerian formulation. To validate the proposed model a prototype was constructed and experimental tests and numerical simulations are accomplished in the time domain, applying harmonic excitations. The results are compared using curves that relate the damping coefficient with the orifice size and with the input velocity applied at the bellows face. However, for the proper control design and system operation, the direct use of the finite element model becomes unviable due to its high computational time. Then, a reduced second order discrete dynamic model for the damper was developed. The model parameters are identified by analysis in the frequency domain, using impulsive excitation force, for constant and variable orifice sizes. At low excitation frequencies, the damper prototype behaves like a single degree of freedom system which damping factor changes with the orifice size A fuzzy controller was designed and it generates the orifice reference size associated to the desired damping factor. The active system presented better performance when compared to the passive one.

  8. SYSTEMS MODELING OF PROSTATE REGULATION AND ...

    Science.gov (United States)

    The prostate is an androgen-dependent tissue that is an important site of disease in human males as well as an important indicator of androgen status in animals. The rat prostate is used for studying antiandrogenic drugs as well as for evaluation of endocrine disruption (e.g., Hershberger Assay). Pubertal changes in the prostate have been observed to be as sensitive to environmental antiandrogens as in utero effects. The goal of this research is to model the biology of prostate androgen function on a systems level to determine the factors responsible for the dose-response observable with androgens and antiandrogens in the male rat. This includes investigation of the roles of positive and negative feedback loops in prostatic response following castration and dosing with testosterone and/or antiandrogens. A biologically-based, systems-level model will be developed describing the regulation of the prostate by androgens. The model will extend an existing model for the male rat central axis, which describes feedback between luteinizing hormone and testosterone production in the testes, to include the prostate and conversion of testosterone to dihydrotestosterone (DHT). The prostate model will describe binding of androgens to the androgen receptor, 5α-reductase catalyzed production of DHT, and gene regulation affecting cell proliferation, apoptosis, and prostatic fluid production. The model will combine pharmacokinetic models for endogenous hormones (i.e., testost

  9. Automatic generation of investigator bibliographies for institutional research networking systems.

    Science.gov (United States)

    Johnson, Stephen B; Bales, Michael E; Dine, Daniel; Bakken, Suzanne; Albert, Paul J; Weng, Chunhua

    2014-10-01

    Publications are a key data source for investigator profiles and research networking systems. We developed ReCiter, an algorithm that automatically extracts bibliographies from PubMed using institutional information about the target investigators. ReCiter executes a broad query against PubMed, groups the results into clusters that appear to constitute distinct author identities and selects the cluster that best matches the target investigator. Using information about investigators from one of our institutions, we compared ReCiter results to queries based on author name and institution and to citations extracted manually from the Scopus database. Five judges created a gold standard using citations of a random sample of 200 investigators. About half of the 10,471 potential investigators had no matching citations in PubMed, and about 45% had fewer than 70 citations. Interrater agreement (Fleiss' kappa) for the gold standard was 0.81. Scopus achieved the best recall (sensitivity) of 0.81, while name-based queries had 0.78 and ReCiter had 0.69. ReCiter attained the best precision (positive predictive value) of 0.93 while Scopus had 0.85 and name-based queries had 0.31. ReCiter accesses the most current citation data, uses limited computational resources and minimizes manual entry by investigators. Generation of bibliographies using named-based queries will not yield high accuracy. Proprietary databases can perform well but requite manual effort. Automated generation with higher recall is possible but requires additional knowledge about investigators. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Calculation and experimental investigation of multi-component ceramic systems

    International Nuclear Information System (INIS)

    Rother, M.

    1994-12-01

    This work shows a way to combine thermodynamic calculations and experiments in order to get useful information on the constitution of metal/non-metal systems. Many data from literature are critically evaluated and used as a basis for experiments and calculations. The following multi-component systems are treated: 1. Multi-component systems of 'ceramic' materials with partially metallic bonding (carbides, nitrides, oxides, borides, carbonitrides, borocarbides, oxinitrides of the 4-8th transition group metals) 2. multi-component systems of non-metallic materials with dominant covalent bonding (SiC, Si 3 N 4 , SiB 6 , BN, Al 4 C 3 , Be 2 C) 3. multi-component systems of non-metallic materials with dominant heteropolar bonding (Al 2 O 3 , TiO 2 , BeO, SiO 2 , ZrO 2 ). The interactions between 1. and 2., 2. and 3., 1. and 3. are also considered. The latest commercially available programmes for the calculation of thermodynamical equilibria and phase diagrams are evaluated and compared considering their facilities and limits. New phase diagrams are presented for many presently unknown multi-component systems; partly known systems are completed on the basis of selected thermodynamic data. The calculations are verified by experimental investigations (metallurgical and powder technology methods). Altogether 690 systems are evaluated, 126 are calculated for the first time and 52 systems are experimentally verified. New data for 60 ternary phases are elaborated by estimating the data limits for the Gibbs energy values. A synthesis of critical evaluation of literature, calculations and experiments leads to new important information about equilibria and reaction behaviour in multi-component systems. This information is necessary to develop new stable and metastable materials. (orig./MM) [de

  11. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component......- and system models match experimental data from the literature. However, limited data were available for verification so further work is necessary to confirm detailed aspects of the models. It is nonetheless expected that the developed models will be useful for system modeling and optimization of PEM fuel...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems...

  12. System modeling of waste flow in energy planning | Njoku | Journal ...

    African Journals Online (AJOL)

    The problem of waste flow in energy system planning was investigated by adopting integrated systems enginee-ring approach. The system model was considered at multiple levels of hierarchy. Waste flow in energy plann-ing process was viewed as a system arranged or organized that plans and policies as controlled ...

  13. Network modelling of physical systems: a geometric approach

    NARCIS (Netherlands)

    van der Schaft, Arjan; Maschke, B.M.; Ortega, Romeo; Banos, A.; Lamnabhi-lagarrigue, F; Montoya, F.J.

    2001-01-01

    It is discussed how network modeling of lumped-parameter physical systems naturally leads to a geometrically defined class of systems, called port-controlled Hamiltonian systems (with dissipation). The structural properties of these systems are investigated, in particular the existence of Casimir

  14. Investigations of instabilities in nuclear matter in stochastic relativistic models

    International Nuclear Information System (INIS)

    Ayik, S.; Yilmaz, O.; Acar, F.; Danisman, B.; Er, N.; Gokalp, A.

    2011-01-01

    The spinodal instabilities for symmetric nuclear matter at finite temperature are studied within different relativistic mean-field models in the semi-classical approximation and the relativistic results are compared with Skyrme type non-relativistic calculations. Qualitatively similar results appear in the unstable response of the system in both non-relativistic and relativistic descriptions. Furthermore, the early growth of baryon, scalar and current density correlation functions are calculated for hot symmetric nuclear matter.

  15. Control system modelling for superconducting accelerator

    International Nuclear Information System (INIS)

    Czarski, T.; Pozniak, K.; Romaniuk, R.

    2006-01-01

    A digital control of superconducting cavities for a linear accelerator is presented. The LLRF - Low Level Radio Frequency system for FLASH project in DESY is introduced. FPGA based controller supported by MATLAB system was developed to investigate the novel firmware implementation. Algebraic model in complex domain is proposed for the system analyzing. Calibration procedure of a signal path is considered for a multi-channel control. Identification of the system parameters is carried out by the least squares method application. Control tables: Feed-Forward and Set- Point are determined for the required cavity performance, according to the recognized process. Feedback loop is tuned by fitting a complex gain of a corrector unit. Adaptive control algorithm is applied for feed-forward and feedback modes. Experimental results are presented for a cavity representative operation. (orig.)

  16. Thermochemical investigations into the system Y-Ba-Cu-O

    International Nuclear Information System (INIS)

    Neuschuetz, D.; Zimmermann, E.; Hack, K.; Boudene, A.; Mohammad, A.

    1992-01-01

    For a consistent thermodynamic description of the quaternary system Y-Ba-Cu-O, the binary and ternary subsystems must be known. The metallic binaries and the ternary system Y-Ba-Cu have been evaluated by the authors. Discrepancies within the Cu-O system made a thorough experimental re-investigation necessary, leading to a new consistent thermodynamic data set for copper-oxygen which can now serve as a basis for the description of phase equilibria of all high temperature superconductors. Extensive experimental work on the ternaries Y-Cu-O and Ba-Cu-O, which are oxygen partial pressure dependent, revealed liquid phases down to 790degC. The ternary Y-Ba-O could be described more easily on the basis of literature values and present experimental results, because it does not contain any liquid phases at relevant temperatures. The representation of the quaternary Y-Ba-Cu-O is complicated both by its dependence on the oxygen potential and the existence of liquid oxide phases. In contrast to common practice, the present investigations had to start from Cu-free Ba-Y-O in order to avoid unknown liquid phases in the experiments. The present results being insufficient for a complete description of the quaternary system, the work is being continued within an EC joint research project. (orig.) With 84 refs., 8 tabs., 47 figs [de

  17. Investigation of dye laser excitation of atomic systems

    International Nuclear Information System (INIS)

    Abate, J.A.

    1977-01-01

    A stabilized cw dye laser system and an optical pumping scheme for a sodium atomic beam were developed, and the improvements over previously existing systems are discussed. A method to stabilize both the output intensity and the frequency of the cw dye laser for periods of several hours is described. The fluctuation properties of this laser are investigated by photon counting and two-time correlation measurements. The results show significant departures from the usual single-mode laser theory in the region of threshold and below. The implications of the deviation from accepted theory are discussed. The atomic beam system that was constructed and tested is described. A method of preparing atomic sodium so that it behaves as a simple two-level atom is outlined, and the results of some experiments to study the resonant interaction between the atoms and the dye laser beam are presented

  18. Investigation of GPS/IMU Positioning System for Mining Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ken L. Stratton

    2006-09-13

    The objective of this project is to investigate the applicability of a combined Global Positioning System and Inertial Measurement Unit (GPS/IMU) for information based displays on earthmoving machines and for automated earthmoving machines in the future. This technology has the potential of allowing an information-based product like Caterpillar's Computer Aided Earthmoving System (CAES) to operate in areas with satellite shading. Satellite shading is an issue in open pit mining because machines are routinely required to operate close to high walls, which reduces significantly the amount of the visible sky to the GPS antenna mounted on the machine. An inertial measurement unit is a product, which provides data for the calculation of position based on sensing accelerations and rotation rates of the machine's rigid body. When this information is coupled with GPS it results in a positioning system that can maintain positioning capability during time periods of shading.

  19. Cognitive models embedded in system simulation models

    International Nuclear Information System (INIS)

    Siegel, A.I.; Wolf, J.J.

    1982-01-01

    If we are to discuss and consider cognitive models, we must first come to grips with two questions: (1) What is cognition; (2) What is a model. Presumably, the answers to these questions can provide a basis for defining a cognitive model. Accordingly, this paper first places these two questions into perspective. Then, cognitive models are set within the context of computer simulation models and a number of computer simulations of cognitive processes are described. Finally, pervasive issues are discussed vis-a-vis cognitive modeling in the computer simulation context

  20. Thermodynamic modeling of complex systems

    DEFF Research Database (Denmark)

    Liang, Xiaodong

    . Contrary to earlier theories, the oil is not only present on the surface, but also in great volumes both in the water column and on the seafloor, which indicates that we do not know enough about how oil behaves in water and interacts with it. Sonar detection is one of the most important and necessary...... after an oil spill. Engineering thermodynamics could be applied in the state-of-the-art sonar products through advanced artificial technology, if the speed of sound, solubility and density of oil-seawater systems could be satisfactorily modelled. The addition of methanol or glycols into unprocessed well...... streams during subsea pipelines is necessary to inhibit gas hydrate formation, and the offshore reservoirs often mean complicated temperature and pressure conditions. Accurate description of the phase behavior and thermalphysical properties of complex systems containing petroleum fluids and polar...

  1. Investigation of energy management strategies for photovoltaic systems - A predictive control algorithm

    Science.gov (United States)

    Cull, R. C.; Eltimsahy, A. H.

    1983-01-01

    The present investigation is concerned with the formulation of energy management strategies for stand-alone photovoltaic (PV) systems, taking into account a basic control algorithm for a possible predictive, (and adaptive) controller. The control system controls the flow of energy in the system according to the amount of energy available, and predicts the appropriate control set-points based on the energy (insolation) available by using an appropriate system model. Aspects of adaptation to the conditions of the system are also considered. Attention is given to a statistical analysis technique, the analysis inputs, the analysis procedure, and details regarding the basic control algorithm.

  2. Flood Water Crossing: Laboratory Model Investigations for Water Velocity Reductions

    Directory of Open Access Journals (Sweden)

    Kasnon N.

    2014-01-01

    Full Text Available The occurrence of floods may give a negative impact towards road traffic in terms of difficulties in mobilizing traffic as well as causing damage to the vehicles, which later cause them to be stuck in the traffic and trigger traffic problems. The high velocity of water flows occur when there is no existence of objects capable of diffusing the water velocity on the road surface. The shape, orientation and size of the object to be placed beside the road as a diffuser are important for the effective flow attenuation of water. In order to investigate the water flow, a laboratory experiment was set up and models were constructed to study the flow velocity reduction. The velocity of water before and after passing through the diffuser objects was investigated. This paper focuses on laboratory experiments to determine the flow velocity of the water using sensors before and after passing through two best diffuser objects chosen from a previous flow pattern experiment.

  3. Microfluidic systems for investigating host-microbe relationship

    Science.gov (United States)

    Bhattacharjee, Arunima; Vincent, Lionel; Nawroth, Janna; Ruby, Ned; McFall-Ngai, Margaret; Kanso, Eva; Biodynamics Laboratory Collaboration; Pacific Biosciences Research Center Collaboration

    2017-11-01

    The symbiosis between the bioluminescent bacterium, Vibrio fisheri, and the Hawaiian bobtail squid, Euprymna scolopes, has been widely studied, and this association is used as a model system for studying bacterial colonization of ciliated host tissues. The recruitment of Vibrio fisheri to a specialized light organ in the nascent squid is facilitated by various chemosensing and mechanosensing events. To decipher the effects of such environmental and host-derived sensors on bacterial physiology, we use specifically designed microfluidic channels to engineer chemical and mechanical fields similar to those observed in the light organ of the squid. These in vitrostudies are aimed at complementing ongoing in vivo studies in the system squid-vibrio system. This approach enables us, for the first time, to isolate the effect of mechanical and chemical cues on bacterial motility in this symbiosis and to quantify the bacterial response to these cues. NSF Inspire.

  4. An investigation of modelling and design for software service applications.

    Science.gov (United States)

    Anjum, Maria; Budgen, David

    2017-01-01

    Software services offer the opportunity to use a component-based approach for the design of applications. However, this needs a deeper understanding of how to develop service-based applications in a systematic manner, and of the set of properties that need to be included in the 'design model'. We have used a realistic application to explore systematically how service-based designs can be created and described. We first identified the key properties of an SOA (service oriented architecture) and then undertook a single-case case study to explore its use in the development of a design for a large-scale application in energy engineering, modelling this with existing notations wherever possible. We evaluated the resulting design model using two walkthroughs with both domain and application experts. We were able to successfully develop a design model around the ten properties identified, and to describe it by adapting existing design notations. A component-based approach to designing such systems does appear to be feasible. However, it needs the assistance of a more integrated set of notations for describing the resulting design model.

  5. An analytical and experimental investigation of natural circulation transients in a model pressurized water reactor

    International Nuclear Information System (INIS)

    Massoud, M.

    1987-01-01

    Natural Circulation phenomena in a simulated PWR was investigated experimentally and analytically. The experimental investigation included determination of system characteristics as well as system response to the imposed transient under symmetric and asymmetric operations. System characteristics were used to obtain correlation for heat transfer coefficient in heat exchangers, system flow resistance, and system buoyancy heat. Asymmetric transients were imposed to study flow oscillation and possible instability. The analytical investigation encompassed development of mathematical model for single-phase, steady-state and transient natural circulation as well as modification of existing model for two-phase flow analysis of phenomena such as small break LOCA, high pressure coolant injection and pump coast down. The developed mathematical model for single-phase analysis was computer coded to simulate the imposed transients. The computer program, entitled ''Symmetric and Asymmetric Analysis of Single-Phase Flow (SAS),'' were employed to simulate the imposed transients. It closely emulated the system behavior throughout the transient and subsequent steady-state. Modifications for two-phase flow analysis included addition of models for once-through steam generator and electric heater rods. Both programs are faster than real time. Off-line, they can be used for prediction and training applications while on-line they serve for simulation and signal validation. The programs can also be used to determine the sensitivity of natural circulation behavior to variation of inputs such as secondary distribution and power transients

  6. An analytical and experimental investigation of natural circulation transients in a model pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Massoud, M

    1987-01-01

    Natural Circulation phenomena in a simulated PWR was investigated experimentally and analytically. The experimental investigation included determination of system characteristics as well as system response to the imposed transient under symmetric and asymmetric operations. System characteristics were used to obtain correlation for heat transfer coefficient in heat exchangers, system flow resistance, and system buoyancy heat. Asymmetric transients were imposed to study flow oscillation and possible instability. The analytical investigation encompassed development of mathematical model for single-phase, steady-state and transient natural circulation as well as modification of existing model for two-phase flow analysis of phenomena such as small break LOCA, high pressure coolant injection and pump coast down. The developed mathematical model for single-phase analysis was computer coded to simulate the imposed transients. The computer program, entitled ''Symmetric and Asymmetric Analysis of Single-Phase Flow (SAS),'' were employed to simulate the imposed transients. It closely emulated the system behavior throughout the transient and subsequent steady-state. Modifications for two-phase flow analysis included addition of models for once-through steam generator and electric heater rods. Both programs are faster than real time. Off-line, they can be used for prediction and training applications while on-line they serve for simulation and signal validation. The programs can also be used to determine the sensitivity of natural circulation behavior to variation of inputs such as secondary distribution and power transients.

  7. A data-stream classification system for investigating terrorist threats

    Science.gov (United States)

    Schulz, Alexia; Dettman, Joshua; Gottschalk, Jeffrey; Kotson, Michael; Vuksani, Era; Yu, Tamara

    2016-05-01

    The role of cyber forensics in criminal investigations has greatly increased in recent years due to the wealth of data that is collected and available to investigators. Physical forensics has also experienced a data volume and fidelity revolution due to advances in methods for DNA and trace evidence analysis. Key to extracting insight is the ability to correlate across multi-modal data, which depends critically on identifying a touch-point connecting the separate data streams. Separate data sources may be connected because they refer to the same individual, entity or event. In this paper we present a data source classification system tailored to facilitate the investigation of potential terrorist activity. This taxonomy is structured to illuminate the defining characteristics of a particular terrorist effort and designed to guide reporting to decision makers that is complete, concise, and evidence-based. The classification system has been validated and empirically utilized in the forensic analysis of a simulated terrorist activity. Next-generation analysts can use this schema to label and correlate across existing data streams, assess which critical information may be missing from the data, and identify options for collecting additional data streams to fill information gaps.

  8. Site investigations: Strategy for rock mechanics site descriptive model

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

  9. Site investigations: Strategy for rock mechanics site descriptive model

    International Nuclear Information System (INIS)

    Andersson, Johan; Christiansson, Rolf; Hudson, John

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate

  10. Reservoir Model Information System: REMIS

    Science.gov (United States)

    Lee, Sang Yun; Lee, Kwang-Wu; Rhee, Taehyun; Neumann, Ulrich

    2009-01-01

    We describe a novel data visualization framework named Reservoir Model Information System (REMIS) for the display of complex and multi-dimensional data sets in oil reservoirs. It is aimed at facilitating visual exploration and analysis of data sets as well as user collaboration in an easier way. Our framework consists of two main modules: the data access point module and the data visualization module. For the data access point module, the Phrase-Driven Grammar System (PDGS) is adopted for helping users facilitate the visualization of data. It integrates data source applications and external visualization tools and allows users to formulate data query and visualization descriptions by selecting graphical icons in a menu or on a map with step-by-step visual guidance. For the data visualization module, we implemented our first prototype of an interactive volume viewer named REMVR to classify and to visualize geo-spatial specific data sets. By combining PDGS and REMVR, REMIS assists users better in describing visualizations and exploring data so that they can easily find desired data and explore interesting or meaningful relationships including trends and exceptions in oil reservoir model data.

  11. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering

  12. Bond graph modeling of centrifugal compression systems

    OpenAIRE

    Uddin, Nur; Gravdahl, Jan Tommy

    2015-01-01

    A novel approach to model unsteady fluid dynamics in a compressor network by using a bond graph is presented. The model is intended in particular for compressor control system development. First, we develop a bond graph model of a single compression system. Bond graph modeling offers a different perspective to previous work by modeling the compression system based on energy flow instead of fluid dynamics. Analyzing the bond graph model explains the energy flow during compressor surge. Two pri...

  13. Structuring Problem Analysis for Embedded Systems Modelling

    NARCIS (Netherlands)

    Marincic, J.; Mader, Angelika H.; Wieringa, Roelf J.; Lucas, Yan

    Our interest is embedded systems validation as part of the model-driven approach. To design a model, the modeller needs to obtain knowledge about the system and decide what is relevant to model and how. A part of the modelling activities is inherently informal - it cannot be formalised in such a way

  14. Fuel Crime Conceptualization through Specialization of Ontology for Investigation Management System

    Science.gov (United States)

    Cybulka, Jolanta

    We undertook the task of building the conceptual model of a particular economic offense, called "a fuel crime". This model is thought of as a part of a larger conceptualization, which comprises consensual semantics underlying the knowledge base of a system, aimed at supporting the teamwork of investigators of economic crimes. Because such a knowledge-based system represents a perspective on economic crimes, it should be carefully modeled. This can be done with the help of an expressive enough ontology. To achieve our goal we use the constructive descriptions and situations (c.DnS) design pattern, which enables us to construct an extensible, layered ontology in a top-down manner: c.DnS top layer is specialized by the reference ontology for investigation management system, that in turn, is specialized by the ontology of the fuel crime.

  15. Developing a Model of the Irish Energy-System

    DEFF Research Database (Denmark)

    Connolly, David; Lund, Henrik; Mathiesen, Brian Vad

    2009-01-01

    to create the model as it accounts for all sectors that need to be considered for integrating large penetrations of renewable energy: the electricity, heat and transport sectors. Before various alternative energy-systems could be investigated for Ireland, a reference model of the existing system needed...

  16. Investigation of the role of water-structured conditions in forming physics-chemical and biological features of the natural and model systems exposed to the energy influences (ecological and technological problems)

    International Nuclear Information System (INIS)

    Eremin, Y.; Belyashov, D.; Yuskov, A.; Kupchishin, A.; Polyakov, A.; Abishev, D.; Bekturov, E.; Adashkin, O.; Sultanbaev, E.; Davydov, G.; Aliev, M.; Verbolovich, V.; Kleinbok, I.; Fryazinova, T.

    1996-01-01

    The project is devoted to solve ecological and technological goals of Semipalatinsk Nuclear Testing Site and uranium industry of Kazakstan. Its anticipated basic results include: - Creation of common systemic research methodology using the spectral, physical-chemical and biological tests; - Development of new testing methods for molecular-structural variations in water systems; evaluation of effect of water and water systems after radiation irradiation upon physical-chemical and biological properties of subjects, which are contacted with these systems; - Determination of a pattern of interaction between the water and the coarse- and fine-dispersions as well as effect of molecular-structural variations in systems upon physical-chemical and biological processes occurred in these systems; - Determination of water role in radiation-chemical reactions by means of electron, gamma- and ion irradiation of water-mineral model systems. There are following basic goals to be solved to reach a general objective of Project: In Water-Mineralogical Section: - To determine a pattern of interaction between the radiant energy and ion and dispersed (hydrophilic and hydrophobic) components; - To clarify a relationship between physical-chemical properties of water with its isotope composition; - To establish a transfer mechanism of micro dispersed radionuclides in geological and soil conditions of SNTS and a role of water structures in hydrophobic interactions between micro dispersions and non-polar radicals of chemical agents; - To determine the water-molecular structure in acid and alkaline water fractions and interspersion interactions within these fractions; - To establish the interaction with water minerals in ice-like and clathrate-like conditions. - In Biological Section: - To study a role of water structure formation and hydrophobic interactions in the modification of humor immunity components for biological liquids being effected by electron and gamma rays beams; - To study the

  17. Investigation of transient models and performances for a doubly fed wind turbine under a grid fault

    DEFF Research Database (Denmark)

    Wang, M.; Zhao, B.; Li, H.

    2011-01-01

    of the grid-side converter and the rotor-side converter of DFIG. Secondly, the transient performances of the presented doubly fed wind turbine under a grid fault were compared and evaluated with different equivalent models, parameters and initial operational conditions. And thirdly, the effects of the active......In order to investigate the impacts of the integration of wind farms into utilities network, it is necessary to analyze the transient performances of wind turbine generation systems (WTGS) with the appropriate transient models. According to the grid code requirements for a wind turbine with doubly...... trip time. Firstly, the different mathematical models of the doubly fed wind turbine were presented, including the electromagnetic transient models of DFIG, a one-mass lumped model, a two-mass shaft flexible model of the wind turbine drive train system, and the power decoupling control strategies...

  18. Investigation of Management Models in Elite Athlete Injuries

    Directory of Open Access Journals (Sweden)

    Shen-Kai Chen

    2005-05-01

    Full Text Available This cross-sectional study investigated management models among elite athletes participating in sports including baseball, basketball, soccer, volleyball, tennis, softball, football, handball, track and field, swimming, judo, tae-kwon-do, gymnastics, archery, and weight lifting at the Tsoying National Sport Training Center. Data were collected by questionnaire. Of the 393 athletes investigated, 56% were male and 44% were female, with an average age of 20.9 years and average length of athletic experience of 9.8 years. At the time of the survey, 74.8% had sporting injuries and were being treated with Chinese and/or Western medicine. Among injured athletes, 14.5% chose Western treatment, 8.1% chose Chinese medicine, and 75.4% received combined treatment. There were various reasons for choosing the management model. Most athletes had ordinary self-recognition of sports injury prevention. Their qualified ability for sports injury prevention was 70%. This ability was significantly correlated with age, education, and sports experience. Within Taiwan's current medical and social environment, elite athletes prefer a combination of Eastern and Western treatments for sports injuries. Each of the medical approaches are widely accepted by elite athletes and their coaches. Doctors trained in Western medicine should learn these alternative treatment methods and apply them effectively in athletes, so that a better medical network can be established.

  19. Investigating factors determining the use of the clinical care module by nurses through the UTAUT model

    CSIR Research Space (South Africa)

    Zhou, M

    2016-08-22

    Full Text Available Nurses can be empowered in the decision making process if provided with objective diagnostic data. This research applied the Unified Theory of Acceptance and Use of Technology model to investigate the usage of electronic health systems and analyse...

  20. Investigating factors determining the use of the clinical care module by nurses through the UTAUT model

    CSIR Research Space (South Africa)

    Zhou, M

    2016-04-01

    Full Text Available Nurses can be empowered in the decision making process if provided with objective diagnostic data. This research applied the Unified Theory of Acceptance and Use of Technology model to investigate the usage of electronic health systems and analyse...

  1. Investigating the northern Adriatic Sea ecosystem state with a very high resolution model

    Science.gov (United States)

    Mattia, Gelsomina; Zavatarelli, Marco; Lovato, Tomas

    2015-04-01

    The northern Adriatic Sea ecosystem dynamics is simulated using the coupling of the BFM (Biogeochemical Flux Model) with the NEMO (Nucleus for European Models of the Ocean) model. The modeling system is implemented at very high horizontal (~800 m) and vertical (95 z-level) resolution and is nested with a coarser scale Adriatic/Mediterranean model. Simulation in hindcast and projection mode are being executed and are aimed to evaluate the ecosystem attributes (vigor, organization, resilience), in order to understand the ecosystem state of the basin with respect to the so-called "Good Ecosystem State" (GES) as defined by the EU-MSF9 Directive. Skill of the model in replicating integrated environmental indices such as the EU-EEACS1023+ is also investigated. Finally the model is also open to an off-line coupling with an higher trophic level (HTL) model.

  2. A program for dynamic noise investigations of reactor systems

    International Nuclear Information System (INIS)

    Antonov, N.A.; Yaneva, N.B.

    1980-01-01

    A stochastic process analysis in nuclear reactors is used for the state diagnosis and dynamic characteristic investigation of the reactor system. A program DENSITY adapted and tested on an IBM 360 ES type computer is developed. The program is adjusted for fast processing of long series exploiting a relatively small memory. The testing procedure is discussed and the method of the periodic sequences corresponding to characteristic reactivity perturbations of the reactor systems is considered. The program is written for calculating the auto-power spectral density and the cross-power spectral density, as well as the coherence function of stationary statistical time series using the advantages of the fast Fourier transformation. In particular, it is shown that the multi-frequency binary sequences are very useful with respect to the signal-to-noise ratio and the frequency distribution in view of the frequency reactor test

  3. Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas I.; Lukas, Sven; Spagnolo, Matteo; Cook, Simon J.; Swift, Darrel A.; Clark, Chris D.; Yde, Jacob C.; Watts, Tom

    2018-01-01

    Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of

  4. Thermal hydraulic investigations and optimization on the EVC system of a PWR by CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Mengmeng [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China); Zhang, Dalin, E-mail: dlzhang@mail.xjtu.edu.cn [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China); Tang, Mao [China Nuclear Power Design Engineering Co., Ltd., 518124 Shenzhen (China); Wang, Chenglong; Zheng, Meiyin; Qiu, Suizheng [Department of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, 710049 Xi’an (China)

    2015-08-15

    Highlights: • This study constructs a full CFD model for the EVC system of a PWR. • The complex fluid and solid coupling is treated in the computation. • Primary characteristics of the velocity, pressure and temperature distributions in the EVC system are investigated. • The optimization of the EVC system with different inlet boundaries are performed. - Abstract: In order to optimize the design of Reactor Pit Ventilation (EVC) system in a Pressurized Water Reactor (PWR), it is necessary to study the characteristics of the velocity, pressure and temperature fields in the EVC system. A full computational fluid dynamics (CFD) model for the EVC system is constructed by a commercial CFD code, where the complex fluid and solid coupling is treated. The Shear Stress Transport (SST) model is adopted to perform the turbulence calculation. This paper numerically investigates the characteristics of the velocity, pressure and temperature distributions in the EVC system. In particular, the effects of inlet air parameters on the thermal hydraulic characteristics and the reactor pit structure are also discussed for the EVC system optimization. Simulations are carried out with different mesh sizes and boundary conditions for sensitivity analysis. The computational results are important references to optimize the design and verify the rationality of the EVC system.

  5. Theoretical model for investigating the dynamic behaviour of the AST-500 type nuclear heating station reactor

    International Nuclear Information System (INIS)

    Grundmann, U.; Rohde, U.; Naumann, B.

    1985-01-01

    Studies on theoretical simulation of the dynamic behaviour of the AST-500 type reactor primary coolant system are summarized. The first version of a dynamic model in the form of the DYNAST code is described. The DYNAST code is based on a one-dimensional description of the primary coolant circuit including core, draught stack, and intermediate heat exchanger, a vapour dome model, and the point model of neutron kinetics. With the aid of the steady-state computational part of the DYNAST code, studies have been performed on different steady-state operating conditions. Furthermore, some methodological investigations on generalization and improvement of the dynamic model are considered and results presented. (author)

  6. Investigation of Scour Depth at Bridge Piers using Bri-Stars Model in Iran

    OpenAIRE

    Gh. Saeidifar; F. Raeiszadeh

    2011-01-01

    BRI-STARS (BRIdge Stream Tube model for Alluvial River Simulation) program was used to investigate the scour depth around bridge piers in some of the major river systems in Iran. Model calibration was performed by collecting different field data. Field data are cataloged on three categories, first group of bridges that their rivers bed are formed by fine material, second group of bridges that their rivers bed are formed by sand material, and finally bridges that their rivers bed a...

  7. Going Underground: A Field Investigation and Lab Activity on Karst Topography and Water Systems

    Science.gov (United States)

    O'Dell, Gary; Gonzalez-Espada, Wilson

    2011-01-01

    Students learn science best with activities that mirror the way scientists work. This article describes how geologists investigate groundwater flow systems in areas of karst topography--geologic formations shaped by dissolving bedrock--and provides a way for students to replicate this research. Students also use electric current to model water…

  8. Further investigations of the NN interaction in the Skyrme model

    International Nuclear Information System (INIS)

    Kaelbermann, G.; Eisenberg, J.M.

    1989-01-01

    We examine the influence of the coupling to NΔ and ΔΔ degrees of freedom for the NN interaction as derived in the Skyrme model, carrying out an extensive search for parameters in the basic Lagrangian that will yield both reasonable single-baryon results and appreciable attraction. Separately the free one-body skyrmeon solution and an improved two-body solution are inserted in the product ansatz for the two-body system both with and without time-dependent dynamical terms. No appreciable central attraction between nucleons is found with either of these approaches. (author)

  9. An Investigation of Digital Instrumentation and Control System Failure Modes

    International Nuclear Information System (INIS)

    Korsah, Kofi; Cetiner, Mustafa Sacit; Muhlheim, Michael David; Poore, Willis P. III

    2010-01-01

    A study sponsored by the Nuclear Regulatory Commission study was conducted to investigate digital instrumentation and control (DI and C) systems and module-level failure modes using a number of databases both in the nuclear and non-nuclear industries. The objectives of the study were to obtain relevant operational experience data to identify generic DI and C system failure modes and failure mechanisms, and to obtain generic insights, with the intent of using results to establish a unified framework for categorizing failure modes and mechanisms. Of the seven databases studied, the Equipment Performance Information Exchange database was found to contain the most useful data relevant to the study. Even so, the general lack of quality relative to the objectives of the study did not allow the development of a unified framework for failure modes and mechanisms of nuclear I and C systems. However, an attempt was made to characterize all the failure modes observed (i.e., without regard to the type of I and C equipment under consideration) into common categories. It was found that all the failure modes identified could be characterized as (a) detectable/preventable before failures, (b) age-related failures, (c) random failures, (d) random/sudden failures, or (e) intermittent failures. The percentage of failure modes characterized as (a) was significant, implying that a significant reduction in system failures could be achieved through improved online monitoring, exhaustive testing prior to installation, adequate configuration control or verification and validation, etc.

  10. Development of Network-type Archaeological Investigation System

    Science.gov (United States)

    Chiba, F.; Yokokoyama, S.; Kaneda, A.; Konno, K.

    2015-08-01

    The Great East Japan Earthquake on March 11, 2011 is said to be a once-in-1000-year catastrophic quake. The Tsunami triggered by the earthquake destroyed broad coastal areas in northeast Japan. As recovery from the earthquake proceeds, the demand for new road construction, housing hill development, and residential construction is rapidly increasing. Culture plays a critical role in the district's recovery. For that reason, before development, cultural properties in the corresponding districts must be urgently investigated. This is a must, although balancing cultural recovery with rapid economic recovery is no easy task. With this in mind, we have developed a new system focusing on speedy archaeological investigation and adequate documentation. The authors reexamined the existing investigation process to categorize tasks into two types: those that must be done only at archaeological sites (site A) and ones available at other places (site B). We then formulated a scheme where the tasks on both sites are performed simultaneously in parallel over the network. Experiments are ongoing. This presentation reports the process and issues of our research and development.

  11. Mars 2020 Model Based Systems Engineering Pilot

    Science.gov (United States)

    Dukes, Alexandra Marie

    2017-01-01

    The pilot study is led by the Integration Engineering group in NASA's Launch Services Program (LSP). The Integration Engineering (IE) group is responsible for managing the interfaces between the spacecraft and launch vehicle. This pilot investigates the utility of Model-Based Systems Engineering (MBSE) with respect to managing and verifying interface requirements. The main objectives of the pilot are to model several key aspects of the Mars 2020 integrated operations and interface requirements based on the design and verification artifacts from Mars Science Laboratory (MSL) and to demonstrate how MBSE could be used by LSP to gain further insight on the interface between the spacecraft and launch vehicle as well as to enhance how LSP manages the launch service. The method used to accomplish this pilot started through familiarization of SysML, MagicDraw, and the Mars 2020 and MSL systems through books, tutorials, and NASA documentation. MSL was chosen as the focus of the model since its processes and verifications translate easily to the Mars 2020 mission. The study was further focused by modeling specialized systems and processes within MSL in order to demonstrate the utility of MBSE for the rest of the mission. The systems chosen were the In-Flight Disconnect (IFD) system and the Mass Properties process. The IFD was chosen as a system of focus since it is an interface between the spacecraft and launch vehicle which can demonstrate the usefulness of MBSE from a system perspective. The Mass Properties process was chosen as a process of focus since the verifications for mass properties occur throughout the lifecycle and can demonstrate the usefulness of MBSE from a multi-discipline perspective. Several iterations of both perspectives have been modeled and evaluated. While the pilot study will continue for another 2 weeks, pros and cons of using MBSE for LSP IE have been identified. A pro of using MBSE includes an integrated view of the disciplines, requirements, and

  12. Experimental investigation into the effects of irradiation with mixed neutron-gamma-rays on the immune system as demonstrated by the model of immunity to Staphylococcal Enterotoxin B in rabbits

    International Nuclear Information System (INIS)

    Kraus, W.

    1984-01-01

    Using the model of immunisation of rabbits with Staphylococcal Enterotoxin B the influence of neutron radiation on the antibody response was investigated. Four groups were formed, which differed by the moment of irradiation with regard to the moment of immunisation and re-immunisation, and were irradiated with neutron-rays of 200 rad and 300 rad doses. Both doses were each given before and after vaccination, respectively before and after re-vaccination. The antibody response has been evaluated by the Radio-Immuno-Assay (RIA): Neutron-radiation given 24 hours before vaccination effects a stronger immune suppression than given 24 hours after vaccination. By pre-antigenic radiation a secondary immune response is more suppressed than by radiation following the antigen; the recovery of lymphoid tissue, however, takes place in a shorter time than in case of radiation before or after a primary vaccination. The secondary antibody response to a re-vaccination is not influenced by a subsequent neutron-radiation. The formation of secondary antibodies is not as radiosensitive as the formation of primary ones. By a neutron-radiation preformed antibodies are hardly damaged. (orig./MG) [de

  13. Modeling Power Systems as Complex Adaptive Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  14. An investigation into the organisation and structural design of multi-computer process-control systems

    International Nuclear Information System (INIS)

    Gertenbach, W.P.

    1981-12-01

    A multi-computer system for the collection of data and control of distributed processes has been developed. The structure and organisation of this system, a study of the general theory of systems and of modularity was used as a basis for an investigation into the organisation and structured design of multi-computer process-control systems. A multi-dimensional model of multi-computer process-control systems was developed. In this model a strict separation was made between organisational properties of multi-computer process-control systems and implementation dependant properties. The model was based on the principles of hierarchical analysis and modularity. Several notions of hierarchy were found necessary to describe fully the organisation of multi-computer systems. A new concept, that of interconnection abstraction was identified. This concept is an extrapolation of implementation techniques in the hardware implementation area to the software implementation area. A synthesis procedure which relies heavily on the above described analysis of multi-computer process-control systems is proposed. The above mentioned model, and a set of performance factors which depend on a set of identified design criteria, were used to constrain the set of possible solutions to the multi-computer process-control system synthesis-procedure

  15. Experimental and numerical investigation of a simplified exhaust model

    Directory of Open Access Journals (Sweden)

    Balázs Vehovszky

    2016-10-01

    Full Text Available A simplified experimental equipment was built to investigate heat radiation and free convection around hot exhaust pipe. Temperatures were measured on the surface of the pipe as like as on heat insulating and -reflecting aluminum shield. Special care was taken to the temperature measuring method: result proved that inappropriate fixing of measuring thermocouples lead to an error of up to 30 % in the temperature-increase values. A detailed 1D numerical model was set up and parametrized so as to the calculation results can be fitted to measured temperature values. In this way thermal properties of the surfaces – as emissivities, absorption coefficients and convective heat transfer coefficients – were determined for temperature sweeps and stationary state cases. The used methods are to be further improved for real automotive parts and higher temperatures.

  16. Experimental investigations and modelling of sodium-concrete interaction

    International Nuclear Information System (INIS)

    Schultheiss, G.F.; Deeg, H.J.

    1990-01-01

    The use of sodium as a coolant in liquid metal fast breeder reactors, fusion reactors, and solar plants requires special consideration of its chemical reactivity and related safety problems in the case of sodium leckage. On contact between hot sodium and concrete an interaction takes place resulting in energy release and hydrogen generation, which may contribute to containment loading by pressurization in a hypothetical accident situation. For this reason, sodium-concrete interactions were investigated experimentally and theoretically. The experiments revealed important effects of quartzitic material within the concrete and of the sodium temperature on the interaction mechanisms, the energy release and the consequent hydrogen production. The numerical model shows good agreement with the experimental results. (orig.) [de

  17. Investigation and modeling of CPL mask profiles using OCD

    Science.gov (United States)

    Chen, Hsuan-Chen; Lin, Ren-Hao; Chen, Chien-Cheng; Huang, Cheng-Hsuan; Lien, Ta-Cheng; Chen, Chia-Jen; Lee, Gaston; Lee, Hsin-Chang; Yen, Anthony

    2016-05-01

    Mask profile of chromeless phase-shifting lithography (CPL) defined by OCD has been investigated. In CPL masks, unbalanced bombardments caused by different ion accelerations lead to the formation of micro-notch structures. A better understanding of micro-notch structures is essential for quality gating of mask processes to improve of CPL mask profiles. By measuring 12 of 16 elements of Mueller matrix, we are able to set up a model to simulate the depth of micro-notch structure profile which shows good correlation with TEM images. Moreover, values of CD, quartz etching depth and side wall angle acquired by OCD are presented and compared with those obtained by SEM, TEM and AFM, respectively.

  18. Experimental investigation and mechanistic modelling of dilute bubbly bulk boiling

    International Nuclear Information System (INIS)

    Kutnjak, Josip

    2013-01-01

    During evaporation the geometric shape of the vapour is not described using thermodynamics. In bubbly flows the bubble shape is considered spheric with small diameters and changing into various shapes upon growth. The heat and mass transfer happens at the interfacial area. The forces acting on the bubbles depend on the bubble diameter and shape. In this work the prediction of the bubble diameter and/or bubble number density in bulk boiling was considered outside the vicinity of the heat input area. Thus the boiling effects that happened inside the nearly saturated bulk were under investigation. This situation is relevant for nuclear safety analysis concerning a stagnant coolant in the spent fuel pool. In this research project a new experimental set-up to investigate was built. The experimental set-up consists of an instrumented, partly transparent, high and slender boiling container for visual observation. The direct visual observation of the boiling phenomena is necessary for the identification of basic mechanisms, which should be incorporated in the simulation model. The boiling process has been recorded by means of video images and subsequently was evaluated by digital image processing methods, and by that data concerning the characteristics of the boiling process were generated for the model development and validation. Mechanistic modelling is based on the derivation of relevant mechanisms concluded from observation, which is in line with physical knowledge. In this context two mechanisms were identified; the growth/-shrink mechanism (GSM) of the vapour bubbles and sudden increases of the bubble number density. The GSM was implemented into the CFD-Code ANSYS-CFX using the CFX Expression Language (CEL) by calculation of the internal bubble pressure using the Young-Laplace-Equation. This way a hysteresis is realised as smaller bubbles have an increased internal pressure. The sudden increases of the bubble number density are explainable by liquid super

  19. Experimental investigation of leak detection using mobile distributed monitoring system

    Science.gov (United States)

    Chen, Jiang; Zheng, Junli; Xiong, Feng; Ge, Qi; Yan, Qixiang; Cheng, Fei

    2018-01-01

    The leak detection of rockfill dams is currently hindered by spatial and temporal randomness and wide monitoring range. The spatial resolution of fiber Bragg grating (FBG) temperature sensing technology is related to the distance between measuring points. As a result, the number of measuring points should be increased to ensure that the precise location of the leak is detected. However, this leads to a higher monitoring cost. Consequently, it is difficult to promote and apply this technology to effectively monitor rockfill dam leakage. In this paper, a practical mobile distributed monitoring system with dual-tubes is used by combining the FBG sensing system and hydrothermal cycling system. This dual-tube structure is composed of an outer polyethylene of raised temperature resistance heating pipe, an inner polytetrafluoroethylene tube, and a FBG sensor string, among which, the FBG sensor string can be dragged freely in the internal tube to change the position of the measuring points and improve the spatial resolution. In order to test the effectiveness of the system, the large-scale model test of concentrated leakage in 13 working conditions is carried out by identifying the location, quantity, and leakage rate of leakage passage. Based on Newton’s law of cooling, the leakage state is identified using the seepage identification index ζ v that was confirmed according to the cooling curve. Results suggested that the monitoring system shows high sensitivity and can improve the spatial resolution with limited measuring points, and thus better locate the leakage area. In addition, the seepage identification index ζ v correlated well with the leakage rate qualitatively.

  20. An investigation of difficulties experienced by students developing unified modelling language (UML) class and sequence diagrams

    Science.gov (United States)

    Sien, Ven Yu

    2011-12-01

    Object-oriented analysis and design (OOAD) is not an easy subject to learn. There are many challenges confronting students when studying OOAD. Students have particular difficulty abstracting real-world problems within the context of OOAD. They are unable to effectively build object-oriented (OO) models from the problem domain because they essentially do not know "what" to model. This article investigates the difficulties and misconceptions undergraduate students have with analysing systems using unified modelling language analysis class and sequence diagrams. These models were chosen because they represent important static and dynamic aspects of the software system under development. The results of this study will help students produce effective OO models, and facilitate software engineering lecturers design learning materials and approaches for introductory OOAD courses.

  1. Zebrafish as a Model to Investigate Dynamin 2-Related Diseases.

    Science.gov (United States)

    Bragato, Cinzia; Gaudenzi, Germano; Blasevich, Flavia; Pavesi, Giulio; Maggi, Lorenzo; Giunta, Michele; Cotelli, Franco; Mora, Marina

    2016-02-04

    Mutations in the dynamin-2 gene (DNM2) cause autosomal dominant centronuclear myopathy (CNM) and dominant intermediate Charcot-Marie-Tooth (CMT) neuropathy type B (CMTDIB). As the relation between these DNM2-related diseases is poorly understood, we used zebrafish to investigate the effects of two different DNM2 mutations. First we identified a new alternatively spliced zebrafish dynamin-2a mRNA (dnm2a-v2) with greater similarity to human DNM2 than the deposited sequence. Then we knocked-down the zebrafish dnm2a, producing defects in muscle morphology. Finally, we expressed two mutated DNM2 mRNA by injecting zebrafish embryos with human mRNAs carrying the R522H mutation, causing CNM, or the G537C mutation, causing CMT. Defects arose especially in secondary motor neuron formation, with incorrect branching in embryos injected with CNM-mutated mRNA, and total absence of branching in those injected with CMT-mutated mRNA. Muscle morphology in embryos injected with CMT-mutated mRNA appeared less regularly organized than in those injected with CNM-mutated mRNA. Our results showing, a continuum between CNM and CMTDIB phenotypes in zebrafish, similarly to the human conditions, confirm this animal model to be a powerful tool to investigate mutations of DNM2 in vivo.

  2. Colloid transport, retention, and remobilization during two-phase flow: Micro-model investigation and modeling

    NARCIS (Netherlands)

    Zhang, Q.

    2013-01-01

    In this study the transport of colloids in a two-phase fluid system is investigated. In particular, the effects on the interface of two immiscible fluids in steady-state and transient circumstances in a micro-porous network are investigated. The experimental setup is designed consisting of micro

  3. Visual computing model for immune system and medical system.

    Science.gov (United States)

    Gong, Tao; Cao, Xinxue; Xiong, Qin

    2015-01-01

    Natural immune system is an intelligent self-organizing and adaptive system, which has a variety of immune cells with different types of immune mechanisms. The mutual cooperation between the immune cells shows the intelligence of this immune system, and modeling this immune system has an important significance in medical science and engineering. In order to build a comprehensible model of this immune system for better understanding with the visualization method than the traditional mathematic model, a visual computing model of this immune system was proposed and also used to design a medical system with the immune system, in this paper. Some visual simulations of the immune system were made to test the visual effect. The experimental results of the simulations show that the visual modeling approach can provide a more effective way for analyzing this immune system than only the traditional mathematic equations.

  4. Physical Model-Based Investigation of Reservoir Sedimentation Processes

    Directory of Open Access Journals (Sweden)

    Cheng-Chia Huang

    2018-03-01

    Full Text Available Sedimentation is a serious problem in the operations of reservoirs. In Taiwan, the situation became worse after the Chi-Chi Earthquake recorded on 21 September 1999. The sediment trap efficiency in several regional reservoirs has been sharply increased, adversely affecting the operations on water supplies. According to the field record, the average annual sediment deposition observed in several regional reservoirs in Taiwan has been increased. For instance, the typhoon event recorded in 2008 at the Wushe Reservoir, Taiwan, produced a 3 m sediment deposit upstream of the dam. The remaining storage capacity in the Wushe Reservoir was reduced to 35.9% or a volume of 53.79 million m3 for flood water detention in 2010. It is urgent that research should be conducted to understand the sediment movement in the Wushe Reservoir. In this study, a scale physical model was built to reproduce the flood flow through the reservoir, investigate the long-term depositional pattern, and evaluate sediment trap efficiency. This allows us to estimate the residual life of the reservoir by proposing a modification of Brune’s method. It can be presented to predict the lifespan of Taiwan reservoirs due to higher applicability in both the physical model and the observed data.

  5. A model for investigating developmental eye repair in Xenopus laevis.

    Science.gov (United States)

    Kha, Cindy X; Son, Philip H; Lauper, Julia; Tseng, Kelly Ai-Sun

    2018-04-01

    Vertebrate eye development is complex and requires early interactions between neuroectoderm and surface ectoderm during embryogenesis. In the African clawed frog, Xenopus laevis, individual eye tissues such as the retina and lens can undergo regeneration. However, it has been reported that removal of either the specified eye field at the neurula stage or the eye during tadpole stage does not induce replacement. Here we describe a model for investigating Xenopus developmental eye repair. We found that tailbud embryos can readily regrow eyes after surgical removal of over 83% of the specified eye and lens tissues. The regrown eye reached a comparable size to the contralateral control by 5 days and overall animal development was normal. It contained the expected complement of eye cell types (including the pigmented epithelium, retina and lens), and is connected to the brain. Our data also demonstrate that apoptosis, an early mechanism that regulates appendage regeneration, is also required for eye regrowth. Treatment with apoptosis inhibitors (M50054 or NS3694) blocked eye regrowth by inhibiting caspase activation. Together, our findings indicate that frog embryos can undergo successful eye repair after considerable tissue loss and reveals a required role for apoptosis in this process. Furthermore, this Xenopus model allows for rapid comparisons of productive eye repair and developmental pathways. It can also facilitate the molecular dissection of signaling mechanisms necessary for initiating repair. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Experimental investigation of statistical models describing distribution of counts

    International Nuclear Information System (INIS)

    Salma, I.; Zemplen-Papp, E.

    1992-01-01

    The binomial, Poisson and modified Poisson models which are used for describing the statistical nature of the distribution of counts are compared theoretically, and conclusions for application are considered. The validity of the Poisson and the modified Poisson statistical distribution for observing k events in a short time interval is investigated experimentally for various measuring times. The experiments to measure the influence of the significant radioactive decay were performed with 89 Y m (T 1/2 =16.06 s), using a multichannel analyser (4096 channels) in the multiscaling mode. According to the results, Poisson statistics describe the counting experiment for short measuring times (up to T=0.5T 1/2 ) and its application is recommended. However, analysis of the data demonstrated, with confidence, that for long measurements (T≥T 1/2 ) Poisson distribution is not valid and the modified Poisson function is preferable. The practical implications in calculating uncertainties and in optimizing the measuring time are discussed. Differences between the standard deviations evaluated on the basis of the Poisson and binomial models are especially significant for experiments with long measuring time (T/T 1/2 ≥2) and/or large detection efficiency (ε>0.30). Optimization of the measuring time for paired observations yields the same solution for either the binomial or the Poisson distribution. (orig.)

  7. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2014-01-01

    Full Text Available This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results.

  8. Model Information Exchange System (MIXS).

    Science.gov (United States)

    2013-08-01

    Many travel demand forecast models operate at state, regional, and local levels. While they share the same physical network in overlapping geographic areas, they use different and uncoordinated modeling networks. This creates difficulties for models ...

  9. Alternative DFN model based on initial site investigations at Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Darcel, C. [Itasca Consultants, Ecully (France); Davy, S.A.P.; Bour, O.; Dreuzy, J.R. de [Geosciences, Rennes (France)

    2004-12-01

    In this report, we provide a first-order analysis of the fracture network at the Simpevarp site. The first order model is the fracture distribution function, noted, fdf, which provides the number of fractures having a given orientation and length, and belonging to a given volume of observation. The first-order distribution model does not describe higher-order correlation between fracture parameters, such as a possible dependency of fracture length distribution with orientations. We also check that most of the information is contained in this 1st-order distribution model, and that dividing the fracture networks into different sets do not bring a better statistical description. The fracture distribution function contains 3 main distributions: the probability distribution of fracture orientations, the dependency on the size of the sampling domain that may exhibit non-trivial scaling in case of fractal correlations, and the fracture-length density distribution, which appears to be well fitted by a power law. The main scaling parameters are the fractal dimension and the power-law exponent of the fracture length distribution. The former was found to be about equal to the embedding dimension, meaning that fractal correlations are weak and can be neglected in the DFN model. The latter depends on geology, that is either lithology or grain size, with values that ranges from 3.2 for granite-like outcrops to 4 for diorite or monzodiorite outcrops, as well as for the large-scale lineament maps. When analyzing the consistency of the different datasets (boreholes, outcrops, lineament maps), we found that two different DFNs can be described: the first one is derived from the fdf of the outcrop with fine-grained size lithology, and is valid across all scales investigated in this study, from the highly-fractured cores to large-scale maps; the second one is derived from the fdf of the outcrops with coarse-grained size lithology, and is found consistent with cores that present the

  10. Investigations of the sensitivity of a coronal mass ejection model (ENLIL) to solar input parameters

    DEFF Research Database (Denmark)

    Falkenberg, Thea Vilstrup; Vršnak, B.; Taktakishvili, A.

    2010-01-01

    Understanding space weather is not only important for satellite operations and human exploration of the solar system but also to phenomena here on Earth that may potentially disturb and disrupt electrical signals. Some of the most violent space weather effects are caused by coronal mass ejections...... investigate the parameter space of the ENLILv2.5b model using the CME event of 25 July 2004. ENLIL is a time‐dependent 3‐D MHD model that can simulate the propagation of cone‐shaped interplanetary coronal mass ejections (ICMEs) through the solar system. Excepting the cone parameters (radius, position...

  11. Two sustainable energy system analysis models

    DEFF Research Database (Denmark)

    Lund, Henrik; Goran Krajacic, Neven Duic; da Graca Carvalho, Maria

    2005-01-01

    This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy.......This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy....

  12. Investigation of land use effects on Nash model parameters

    Science.gov (United States)

    Niazi, Faegheh; Fakheri Fard, Ahmad; Nourani, Vahid; Goodrich, David; Gupta, Hoshin

    2015-04-01

    Flood forecasting is of great importance in hydrologic planning, hydraulic structure design, water resources management and sustainable designs like flood control and management. Nash's instantaneous unit hydrograph is frequently used for simulating hydrological response in natural watersheds. Urban hydrology is gaining more attention due to population increases and associated construction escalation. Rapid development of urban areas affects the hydrologic processes of watersheds by decreasing soil permeability, flood base flow, lag time and increase in flood volume, peak runoff rates and flood frequency. In this study the influence of urbanization on the significant parameters of the Nash model have been investigated. These parameters were calculated using three popular methods (i.e. moment, root mean square error and random sampling data generation), in a small watershed consisting of one natural sub-watershed which drains into a residentially developed sub-watershed in the city of Sierra Vista, Arizona. The results indicated that for all three methods, the lag time, which is product of Nash parameters "K" and "n", in the natural sub-watershed is greater than the developed one. This logically implies more storage and/or attenuation in the natural sub-watershed. The median K and n parameters derived from the three methods using calibration events were tested via a set of verification events. The results indicated that all the three method have acceptable accuracy in hydrograph simulation. The CDF curves and histograms of the parameters clearly show the difference of the Nash parameter values between the natural and developed sub-watersheds. Some specific upper and lower percentile values of the median of the generated parameters (i.e. 10, 20 and 30 %) were analyzed to future investigates the derived parameters. The model was sensitive to variations in the value of the uncertain K and n parameter. Changes in n are smaller than K in both sub-watersheds indicating

  13. Investigating the Process of Process Modeling with Eye Movement Analysis

    OpenAIRE

    Pinggera, Jakob; Furtner, Marco; Martini, Markus; Sachse, Pierre; Reiter, Katharina; Zugal, Stefan; Weber, Barbara

    2015-01-01

    Research on quality issues of business process models has recently begun to explore the process of creating process models by analyzing the modeler's interactions with the modeling environment. In this paper we aim to complement previous insights on the modeler's modeling behavior with data gathered by tracking the modeler's eye movements when engaged in the act of modeling. We present preliminary results and outline directions for future research to triangulate toward a more comprehensive un...

  14. Models for multimegawatt space power systems

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.

    1990-06-01

    This report describes models for multimegawatt, space power systems which Sandia's Advanced Power Systems Division has constructed to help evaluate space power systems for SDI's Space Power Office. Five system models and models for associated components are presented for both open (power system waste products are exhausted into space) and closed (no waste products) systems: open, burst mode, hydrogen cooled nuclear reactor -- turboalternator system; open, hydrogen-oxygen combustion turboalternator system; closed, nuclear reactor powered Brayton cycle system; closed, liquid metal Rankine cycle system; and closed, in-core, reactor therminonic system. The models estimate performance and mass for the components in each of these systems. 17 refs., 8 figs., 15 tabs.

  15. Clinical investigations for SUS, the Brazilian public health system.

    Science.gov (United States)

    Paula, Ana Patrícia de; Giozza, Silvana Pereira; Pereira, Michelle Zanon; Boaventura, Patrícia Souza; Santos, Leonor Maria Pacheco; Sachetti, Camile Giaretta; Tamayo, César Omar Carranza; Kowalski, Clarissa Campos Guaragna; Elias, Flavia Tavares Silva; Serruya, Suzanne Jacob; Guimarães, Reinaldo

    2012-01-01

    Scientific and technological development is crucial for advancing the Brazilian health system and for promoting quality of life. The way in which the Brazilian Ministry of Health has supported clinical research to provide autonomy, self-sufficiency, competitiveness and innovation for the healthcare industrial production complex, in accordance with the National Policy on Science, Technology and Innovation in Healthcare, was analyzed. Descriptive investigation, based on secondary data, conducted at the Department of Science and Technology, Ministry of Health. The Ministry of Health's research management database, PesquisaSaúde, was analyzed from 2002 to 2009, using the key word "clinical research" in the fields "primary sub-agenda" or "secondary sub-agenda". The 368 projects retrieved were sorted into six categories: basic biomedical research, preclinical studies, expanded clinical research, clinical trials, infrastructure support and health technology assessment. From a structured review on "clinical research funding", results from selected countries are presented and discussed. The amount invested was R$ 140 million. The largest number of projects supported "basic biomedical research", while the highest amounts invested were in "clinical trials" and "infrastructure support". The southeastern region had the greatest proportion of projects and financial resources. In some respects, Brazil is ahead of other BRICS countries (Russia, India, China and South Africa), especially with regard to establishing a National Clinical Research Network. The Ministry of Health ensured investments to encourage clinical research in Brazil and contributed towards promoting cohesion between investigators, health policies and the healthcare industrial production complex.

  16. Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

    International Nuclear Information System (INIS)

    Miller, John; Sibley Lewis, B.; Wohlgemuth, John

    1999-01-01

    This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs

  17. Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John; Sibley, Lewis, B.; Wohlgemuth, John

    1999-06-01

    This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs.

  18. The influence of the magnetoelastic interaction on the magnetocaloric effect in ferrimagnetic systems: a theoretical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Alho, B P; De Oliveira, N A; De Sousa, V S R; Von Ranke, P J [Instituto de Fisica ' Armando Dias Tavares' , Universidade do Estado do Rio de Janeiro-UERJ, Rua Sao Francisco Xavier 524, 20550-013, RJ (Brazil); Plaza, E J R [Departamento de Fisica, Universidade Federal de Sergipe, 49100-000, Sao Cristovao, Sergipe (Brazil); Magnus G Carvalho, A, E-mail: brunoalho@gmail.co [Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), 25250-020, Duque de Caxias, RJ (Brazil)

    2010-12-08

    In this work the magnetocaloric effect is theoretically investigated considering a microscopic model Hamiltonian, which describes a magnetic system formed by two sublattices of different magnetic ions coupled by exchange and magnetoelastic interactions. We analyze systematically several profiles of the ferrimagnetic arrangements that were studied earlier without the magnetoelastic interaction. The influence of changing the magnetoelastic parameters on the magnetization, isothermal entropy change and adiabatic temperature change curves are investigated. Depending on the model parameters, the magnetic system shows a first-order magnetic phase transition leading to high direct and inverse magnetocaloric effect, besides two simultaneous first-order magnetic phase transitions which were predicted. A constant {Delta}S{sub T} = 0.4 J mol{sup -1} K{sup -1} is obtained in the simulated system in a temperature interval of 50 K, around 110 K.

  19. A new CFD modeling method for flow blockage accident investigations

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wenyuan, E-mail: fanwy@mail.ustc.edu.cn; Peng, Changhong, E-mail: pengch@ustc.edu.cn; Chen, Yangli, E-mail: chenyl@mail.ustc.edu.cn; Guo, Yun, E-mail: guoyun79@ustc.edu.cn

    2016-07-15

    Highlights: • Porous-jump treatment is applied to CFD simulation on flow blockages. • Porous-jump treatment predicts consistent results with direct CFD treatment. • Relap5 predicts abnormal flow rate profiles in MTR SFA blockage scenario. • Relap5 fails to simulate annular heat flux in blockage case of annular assembly. • Porous-jump treatment provides reasonable and generalized CFD results. - Abstract: Inlet flow blockages in both flat and annular plate-type fuel assemblies are simulated by (Computational Fluid Dynamics) CFD and system analysis methods, with blockage ratio ranging from 60 to 90%. For all the blockage scenarios, mass flow rate of the blocked channel drops dramatically as blockage ratio increases, while mass flow rates of non-blocked channels are almost steady. As a result of over-simplifications, the system code fails to capture details of mass flow rate profiles of non-blocked channels and power redistribution of fuel plates. In order to acquire generalized CFD results, a new blockage modeling method is developed by using the porous-jump condition. For comparisons, direct CFD simulations are conducted toward postulated blockages. For the porous-jump treatment, conservative flow and heat transfer conditions are predicted for the blocked channel, while consistent predictions are obtained for non-blocked channels. Besides, flow fields in the blocked channel, asymmetric power redistributions of fuel plates, and complex heat transfer phenomena in annular fuel assembly are obtained and discussed. The present study indicates that the porous-jump condition is a reasonable blockage modeling method, which predicts generalized CFD results for flow blockages.

  20. Geotechnical environmental inhomogeneity monitoring by visualization of surface and subsurface electrode array resistivity data. Investigation by simple predictable models in earth resources information system engineering; Chihyo oyobi chichu denkyoku riyohi teiko data ni yoru jiban fukinshitsu kankyo no chika joho kashika monitoring. Shigen joho system kogaku ni okeru tanjunna model no sotei to sono yosoku

    Energy Technology Data Exchange (ETDEWEB)

    Sugano, T.; Ogawa, J.; Moriyama, D.; Kishi, W.

    1998-02-10

    Data of potentials and resistivity obtained by surficial and underground electrodes are utilized for the study of underground information visualization. Current sources are given by dots, to be analyzed by the use of an finite element method 2D-3D algorithm. Resistivity is analyzed as a 2D structure, with the analysis model x-axis made to squarely cross the run of underground structure and the z-axis designated to be positive in the downward direction. In a 3D Poisson equation, Fourier transformation and 2D Helmholtz equation are solved relative to the y axis (structure run direction). The boundary conditions of the x and z are considered for a solution in the domain of investigation, and the use of inverse Fourier transformation determines the potentials distribution in the 3D space. When apparent resistivity due to actual electrode arrangement is calculated based on this potentials distribution and is reverse-analyzed, the underground resistivity distribution may be picturized. To put this technique to practical use, studies are conducted of the assumption of a simple model and prediction accuracy, basics of resistivity data analysis, and fundamental problems in the effective use of resistivity data utilizing the surficial and underground electrodes. A conclusion is reached as to what direction the basic policy should face. 20 refs., 16 figs., 1 tab.

  1. The armenian power system operation stability investigation accounting putting new power systems into operation

    International Nuclear Information System (INIS)

    Yeghiazaryan, L.V.; Hakobyan, S.G.; Gharibyan, G.V.; Harutyunyan, G.S.; Galstyan, G.H.

    2010-01-01

    The description of the power systems operation stability failure caused by the system significant emergency states occurred during the last working period in Armenian and USA power systems is performed. With the use of PSSTME-31 software portfolio of Siemens Firm a design model is developed and transient electromechanical process calculations for Armenian power system are performed. The accuracy of the model is checked by comparing real-time transient state parameters and their reproduction calculation results.The Armenia - Iran current power transmission lines permissible limit under the condition of the static and dynamic stability requirements and in case of the new thermal power units maintenance are defined

  2. Modeling traceability in system of systems

    NARCIS (Netherlands)

    Tekinerdogan, Bedir; Erata, Ferhat

    2017-01-01

    An important aspect in SoS is the realization of the concerns in different systems that work together. Identifying and locating these concerns is important to orchestrate the overall activities and hereby to achieve the overall goal of the SoS. Moreover, concerns in SoS are rarely stable and need

  3. Scientific investigation plan for initial engineered barrier system field tests

    International Nuclear Information System (INIS)

    Wunan Lin.

    1993-02-01

    The purpose of this Scientific Investigation Plan (SIP) is to describe tests known as Initial Engineered Barrier System Field Tests (IEBSFT) and identified by Work Breakdown Structure as WBS 1.2.2.2.4. The IEBSFT are precursors to the Engineered Barrier System Field Test (EBSFT), WBS 1.2.2.2.4, to be conducted in the Exploratory Study Facility (ESF) at Yucca Mountain. The EBSFT and IEBSFT are designed to provide information on the interaction between waste packages (simulated by heated containers) and the surrounding rock mass, its vadose water, and infiltrated water. Heater assemblies will be installed in drifts or boreholes openings and heated to measure moisture movement during heat-up and subsequent cool-down of the rock mass. In some of the tests, infiltration of water into the heated rock mass will be studied. Throughout the heating and cooling cycle, instruments installed in the rock will monitor such parameters as temperature, moisture content, concentration of some chemical species, and stress and strain. Rock permeability measurements, rock and fluid (water and gas) sampling, and fracture pattern measurements will also be made before and after the test

  4. Lab-on-a-chip systems for photodynamic therapy investigations.

    Science.gov (United States)

    Chudy, Michał; Tokarska, Katarzyna; Jastrzębska, Elżbieta; Bułka, Magdalena; Drozdek, Sławomir; Lamch, Łukasz; Wilk, Kazimiera A; Brzózka, Zbigniew

    2018-03-15

    In recent years photodynamic therapy (PDT) has received widespread attention in cancer treatment due to its smaller surgical trauma, better selectivity towards tumor cells, reduced side effects and possibility of repeatable treatment. Since cancer is the second cause of death worldwide, scientists constantly seek for new potential therapeutic agents including nanotechnology-based photosensitizers used in PDT. The new-designed nanostructures must be carefully studied and well characterized what require analytically useful and powerful tools that enable real progress in nanoscience development. This review describes the current status of PDT investigations using microfluidic Lab-on-a-Chip systems, including recent developments of nanoparticle-based PDT agents, their combinations with different drugs, designs and examples of in vitro applications. This review mainly lays emphasis on biological evaluation of FDA approved photosensitizing agents as well as newly designed nanophotosensitizers. It also highlights the analytical performances of various microfluidic Lab-on-a-chip systems for PDT efficacy analysis on 3D culture and discusses microsystems designs in detail. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Investigations in Satellite MIMO Channel Modeling: Accent on Polarization

    Directory of Open Access Journals (Sweden)

    Karagiannidis George K

    2007-01-01

    Full Text Available Due to the much different environment in satellite and terrestrial links, possibilities in and design of MIMO systems are rather different as well. After pointing out these differences and problems arising from them, two MIMO designs are shown rather well adapted to satellite link characteristics. Cooperative diversity seems to be applicable; its concept is briefly presented without a detailed discussion, leaving solving particular satellite problems to later work. On the other hand, a detailed discussion of polarization time-coded diversity (PTC is given. A physical-statistical model for dual-polarized satellite links is presented together with measuring results validating the model. The concept of 3D polarization is presented as well as briefly describing compact 3D-polarized antennas known from the literature and applicable in satellite links. A synthetic satellite-to-indoor link is constructed and its electromagnetic behavior is simulated via the FDTD (finite-difference time-domain method. Previous result of the authors states that in 3D-PTC situations, MIMO capacity can be about two times higher than SIMO (single-input multiple-output capacity while a diversity gain of nearly is further verified via extensive FDTD computer simulation.

  6. Investigations in Satellite MIMO Channel Modeling: Accent on Polarization

    Directory of Open Access Journals (Sweden)

    Péter Horváth

    2007-05-01

    Full Text Available Due to the much different environment in satellite and terrestrial links, possibilities in and design of MIMO systems are rather different as well. After pointing out these differences and problems arising from them, two MIMO designs are shown rather well adapted to satellite link characteristics. Cooperative diversity seems to be applicable; its concept is briefly presented without a detailed discussion, leaving solving particular satellite problems to later work. On the other hand, a detailed discussion of polarization time-coded diversity (PTC is given. A physical-statistical model for dual-polarized satellite links is presented together with measuring results validating the model. The concept of 3D polarization is presented as well as briefly describing compact 3D-polarized antennas known from the literature and applicable in satellite links. A synthetic satellite-to-indoor link is constructed and its electromagnetic behavior is simulated via the FDTD (finite-difference time-domain method. Previous result of the authors states that in 3D-PTC situations, MIMO capacity can be about two times higher than SIMO (single-input multiple-output capacity while a diversity gain of nearly 2×3 is further verified via extensive FDTD computer simulation.

  7. Modeling of Nonlinear Systems using Genetic Algorithm

    Science.gov (United States)

    Hayashi, Kayoko; Yamamoto, Toru; Kawada, Kazuo

    In this paper, a newly modeling system by using Genetic Algorithm (GA) is proposed. The GA is an evolutionary computational method that simulates the mechanisms of heredity or evolution of living things, and it is utilized in optimization and in searching for optimized solutions. Most process systems have nonlinearities, so it is necessary to anticipate exactly such systems. However, it is difficult to make a suitable model for nonlinear systems, because most nonlinear systems have a complex structure. Therefore the newly proposed method of modeling for nonlinear systems uses GA. Then, according to the newly proposed scheme, the optimal structure and parameters of the nonlinear model are automatically generated.

  8. An Investigation of Feature Models for Music Genre Classification using the Support Vector Classifier

    DEFF Research Database (Denmark)

    Meng, Anders; Shawe-Taylor, John

    2005-01-01

    In music genre classification the decision time is typically of the order of several seconds however most automatic music genre classification systems focus on short time features derived from 10-50ms. This work investigates two models, the multivariate gaussian model and the multivariate...... probability kernel. In order to examine the different methods an 11 genre music setup was utilized. In this setup the Mel Frequency Cepstral Coefficients (MFCC) were used as short time features. The accuracy of the best performing model on this data set was 44% as compared to a human performance of 52...

  9. In Search for Universal Models. Dimerization of Nitrosobenzenes and Investigation of Some Basic Chemical Concepts

    Directory of Open Access Journals (Sweden)

    Biljan, I.

    2012-09-01

    Full Text Available One of the most exploited approaches in scientific methodology is studying concepts by using a case study. In chemistry, a case study appears in finding a specific molecular and/or reaction system by which the investigated problem can be observed directly "on substance". Thus, the stu- died problem becomes a concrete system, rather than an abstract concept. Most case-study models are designed specifically to deepen one or another chemical problem. However, there exist (although rarely models, which afford their universality, i.e. could serve for modeling of qui- te different, and even epistemologically independent concepts. Systematic investigations of the chemistry of C-nitroso compounds performed in our Laboratory in last few years, have resulted in the discovery that such molecular system may be used as a model for studying a series of basic chemical concepts; selectivity, self-assembly, solid-state reaction mechanisms, photochromism and molecular logics. Since it is known that C-nitroso compounds under specific conditions dime- rize by forming new N=N bond (Scheme 1, the reaction can be used for studying selectivity in the formation of dimers between different nitroso monomers (Fig. 1 and Fig. 2. The system is very convenient for investigation of the structure-selectivity relations.6 It has already been established, especially in the work of Brian Gowenlock, that nitroso compounds in crystal form appear as di- mers. These discoveries inspired us to investigate the kinetics and mechanism of dimerization of nitroso monomers in solid state, because the freshly sublimed nitrosoaromatic compounds appear as crystals of monomers. Consequently, this molecular system is a perfect case-study model for concepts of solid-state reactions, self-organizations in the crystalline forms (Fig. 3, as well as for the8,13 Extending our research of self-organization of nitroso compounds to two-dimensional systems (Fig. 4, we have also de- monstrated the ability of

  10. Results of EPRI/ANL DCH investigations and model development

    International Nuclear Information System (INIS)

    Spencer, B.W.; Sienicki, J.J.; Sehgal, B.R.; Merilo, M.

    1988-01-01

    The results of a series of five experiments are described addressing the severity and mitigation of direct containment heating. The tests were performed in a 1:30 linear scale mockup of the Zion PWR containment system using a reactor-material corium melt consisting of 60% UO 2 , 16% ZrO 2 , 24% SSt at nominally 2800C initial temperature. A ''worst-case'' type test involving unimpeded corium dispersal through an air atmosphere in a closed vessel produced an atmosphere heatup of 323K, equivalent to a DCH efficiency of 62%. With the addition of structural features which impeded the corium dispersal, representative of dispersal pathway features at Zion, the DCH efficiency was reduced to 1--5%. (This important result is scale dependent and requires larger scale tests such as the SURTSEY program at SNL plus mechanistic modeling for application to the reactor system.) With the addition of water in the cavity region, there was no measurable heatup of the atmosphere. This was attributable to the vigorous codispersal of water with corium which prevented the temperature of the atmosphere from significantly exceeding T/sub sat/. In this case the DCH load was replaced by the more benign ''steam spike'' from corium quench. Significant oxidation of the corium constituents occurred in the tests, adding chemical energy to the system and producing hydrogen. Overall, the results suggest that with consideration of realistic, plant specific, mitigating features, DCH may be no worse and possibly far less severe than the previously examined steam spike. Implications for accident management are addressed. 17 refs., 7 figs., 4 tabs

  11. Model Driven Development of Data Sensitive Systems

    DEFF Research Database (Denmark)

    Olsen, Petur

    2014-01-01

    to the values of variables. This theses strives to improve model-driven development of such data-sensitive systems. This is done by addressing three research questions. In the first we combine state-based modeling and abstract interpretation, in order to ease modeling of data-sensitive systems, while allowing...... efficient model-checking and model-based testing. In the second we develop automatic abstraction learning used together with model learning, in order to allow fully automatic learning of data-sensitive systems to allow learning of larger systems. In the third we develop an approach for modeling and model-based...... detection and pushing error detection to earlier stages of development. The complexity of modeling and the size of systems which can be analyzed is severely limited when introducing data variables. The state space grows exponentially in the number of variable and the domain size of the variables...

  12. Modeling of a Hydraulic Braking System

    OpenAIRE

    Lundin, Christopher

    2015-01-01

    The objective of this thesis is to derive an analytical model representing a reduced form of a mine hoist hydraulic braking system. Based primarily on fluid mechanical and mechanical physical modeling, along with a number of simplifying assumptions, the analytical model will be derived and expressed in the form of a system of differential equations including a set of static functions. The obtained model will be suitable for basic simulation and analysis of system dynamics, with the aim to cap...

  13. Qualitative models and experimental investigation of chaotic NOR gates and set/reset flip-flops

    Science.gov (United States)

    Rahman, Aminur; Jordan, Ian; Blackmore, Denis

    2018-01-01

    It has been observed through experiments and SPICE simulations that logical circuits based upon Chua's circuit exhibit complex dynamical behaviour. This behaviour can be used to design analogues of more complex logic families and some properties can be exploited for electronics applications. Some of these circuits have been modelled as systems of ordinary differential equations. However, as the number of components in newer circuits increases so does the complexity. This renders continuous dynamical systems models impractical and necessitates new modelling techniques. In recent years, some discrete dynamical models have been developed using various simplifying assumptions. To create a robust modelling framework for chaotic logical circuits, we developed both deterministic and stochastic discrete dynamical models, which exploit the natural recurrence behaviour, for two chaotic NOR gates and a chaotic set/reset flip-flop. This work presents a complete applied mathematical investigation of logical circuits. Experiments on our own designs of the above circuits are modelled and the models are rigorously analysed and simulated showing surprisingly close qualitative agreement with the experiments. Furthermore, the models are designed to accommodate dynamics of similarly designed circuits. This will allow researchers to develop ever more complex chaotic logical circuits with a simple modelling framework.

  14. Graphical Model Debugger Framework for Embedded Systems

    DEFF Research Database (Denmark)

    Zeng, Kebin

    2010-01-01

    Model Driven Software Development has offered a faster way to design and implement embedded real-time software by moving the design to a model level, and by transforming models to code. However, the testing of embedded systems has remained at the code level. This paper presents a Graphical Model...... Debugger Framework, providing an auxiliary avenue of analysis of system models at runtime by executing generated code and updating models synchronously, which allows embedded developers to focus on the model level. With the model debugger, embedded developers can graphically test their design model...... and check the running status of the system, which offers a debugging capability on a higher level of abstraction. The framework intends to contribute a tool to the Eclipse society, especially suitable for model-driven development of embedded systems....

  15. Investigation of advanced materials based on low-dimensional systems

    International Nuclear Information System (INIS)

    Babenkov, Sergey

    2016-11-01

    In the framework of this thesis, a new end-station dedicated for dynamic-XPS measurements is created. The end-station is based on a new hemispherical electron spectrometer Argus which is equipped with a high speed detection system. In combination with the high brilliance XUV beamline P04 at PETRA III it provides users a unique tool for fast (down to 0.1 s/spectrum) and detailed investigations compared to existing XPS devices at other synchrotrons. This end-station is integrated into beamline P04 and available for users. During this research work it was widely used for fabrication of samples (Ar + sputtering, sample heating, film growth etc) and investigation of their properties by means of dynamic-XPS. Using several methods, the atomic and electronic structure of graphene grown on technically relevant substrates of cubic-SiC(001)/Si(001) (''on-axis'' and ''vicinal'') was investigated. We have shown a way to control the number of graphene layers by real-time photoemission measurements during preparation procedure. Using this approach, we have synthesized several samples with different numbers of graphene layers. Consequent atomically resolved STM studies prove the synthesis of a uniform, millimeter-scale graphene overlayer. At the same time, the graphene overlayer possesses rippled morphology and consists of large amount of domain boundaries. Directions of domain boundaries coincide with the directions of carbon atomic chains which were fabricated prior to graphene synthesis on the SiC(001)-c(2 x 2) surface reconstruction. Further, using vicinal-SiC, we synthesized Bernal-stacked trilayer graphene with self-aligned periodic nanodomain boundaries. We proposed a simple method to achieve a current On-Off ratio of 104 by opening a transport gap in Bernal-stacked trilayer graphene. Our low-temperature transport measurements clearly demonstrate that the self-aligned periodic NBs can induce a charge transport gap greater than 1.3 e

  16. Investigation of advanced materials based on low-dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Babenkov, Sergey

    2016-11-15

    In the framework of this thesis, a new end-station dedicated for dynamic-XPS measurements is created. The end-station is based on a new hemispherical electron spectrometer Argus which is equipped with a high speed detection system. In combination with the high brilliance XUV beamline P04 at PETRA III it provides users a unique tool for fast (down to 0.1 s/spectrum) and detailed investigations compared to existing XPS devices at other synchrotrons. This end-station is integrated into beamline P04 and available for users. During this research work it was widely used for fabrication of samples (Ar{sup +} sputtering, sample heating, film growth etc) and investigation of their properties by means of dynamic-XPS. Using several methods, the atomic and electronic structure of graphene grown on technically relevant substrates of cubic-SiC(001)/Si(001) (''on-axis'' and ''vicinal'') was investigated. We have shown a way to control the number of graphene layers by real-time photoemission measurements during preparation procedure. Using this approach, we have synthesized several samples with different numbers of graphene layers. Consequent atomically resolved STM studies prove the synthesis of a uniform, millimeter-scale graphene overlayer. At the same time, the graphene overlayer possesses rippled morphology and consists of large amount of domain boundaries. Directions of domain boundaries coincide with the directions of carbon atomic chains which were fabricated prior to graphene synthesis on the SiC(001)-c(2 x 2) surface reconstruction. Further, using vicinal-SiC, we synthesized Bernal-stacked trilayer graphene with self-aligned periodic nanodomain boundaries. We proposed a simple method to achieve a current On-Off ratio of 104 by opening a transport gap in Bernal-stacked trilayer graphene. Our low-temperature transport measurements clearly demonstrate that the self-aligned periodic NBs can induce a charge transport gap greater than 1

  17. Audiovisual Rehabilitation in Hemianopia: A Model-Based Theoretical Investigation

    Science.gov (United States)

    Magosso, Elisa; Cuppini, Cristiano; Bertini, Caterina

    2017-01-01

    translate visual stimuli into short-latency saccades, possibly moving the stimuli into visual detection regions. The retina-SC-extrastriate circuit is related to restitutive effects: visual stimuli can directly elicit visual detection with no need for eye movements. Model predictions and assumptions are critically discussed in view of existing behavioral and neurophysiological data, forecasting that other oculomotor compensatory mechanisms, beyond short-latency saccades, are likely involved, and stimulating future experimental and theoretical investigations. PMID:29326578

  18. Audiovisual Rehabilitation in Hemianopia: A Model-Based Theoretical Investigation

    Directory of Open Access Journals (Sweden)

    Elisa Magosso

    2017-12-01

    circuit can translate visual stimuli into short-latency saccades, possibly moving the stimuli into visual detection regions. The retina-SC-extrastriate circuit is related to restitutive effects: visual stimuli can directly elicit visual detection with no need for eye movements. Model predictions and assumptions are critically discussed in view of existing behavioral and neurophysiological data, forecasting that other oculomotor compensatory mechanisms, beyond short-latency saccades, are likely involved, and stimulating future experimental and theoretical investigations.

  19. Dynamic modelling as an element of the availibility and process oriented behaviour investigation of complex power plants; Dynamische Modellbildung als Element von verfuegbarkeits- und prozessorientierten Untersuchungen komplexer kraftwerkstechnischer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Klatt, M.

    2007-12-20

    A software-tool was developed, which, with its specially built component library, allows the modelling of availability and dynamic behaviour of large scale power plant units. The requested graphic representation near to the process flow schema required a search for new ways of data and information flow modelling. The large quantity of components of a power plant unit with its most important components thereby requires a block oriented modelling approach based on lumped and distributed lumped parameters. (orig.)

  20. Hydrological modelling in forested systems

    Science.gov (United States)

    This chapter provides a brief overview of forest hydrology modelling approaches for answering important global research and management questions. Many hundreds of hydrological models have been applied globally across multiple decades to represent and predict forest hydrological p...

  1. Towards Modelling of Hybrid Systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2006-01-01

    The article is an attempt to use methods of category theory and topology for analysis of hybrid systems. We use the notion of a directed topological space; it is a topological space together with a set of privileged paths. Dynamical systems are examples of directed topological spaces. A hybrid...... system consists of a number of dynamical systems that are glued together according to information encoded in the discrete part of the system. We develop a definition of a hybrid system as a functor from the category generated by a transition system to the category of directed topological spaces. Its...... directed homotopy colimit (geometric realization) is a single directed topological space. The behavior of hybrid systems can be then understood in terms of the behavior of dynamical systems through the directed homotopy colimit....

  2. Clinical investigations for SUS, the Brazilian public health system

    Directory of Open Access Journals (Sweden)

    Ana Patrícia de Paula

    Full Text Available CONTEXT AND OBJECTIVE: Scientific and technological development is crucial for advancing the Brazilian health system and for promoting quality of life. The way in which the Brazilian Ministry of Health has supported clinical research to provide autonomy, self-sufficiency, competitiveness and innovation for the healthcare industrial production complex, in accordance with the National Policy on Science, Technology and Innovation in Healthcare, was analyzed. DESIGN AND SETTING: Descriptive investigation, based on secondary data, conducted at the Department of Science and Technology, Ministry of Health. METHODS: The Ministry of Health's research management database, PesquisaSaúde, was analyzed from 2002 to 2009, using the key word "clinical research" in the fields "primary sub-agenda" or "secondary sub-agenda". The 368 projects retrieved were sorted into six categories: basic biomedical research, preclinical studies, expanded clinical research, clinical trials, infrastructure support and health technology assessment. From a structured review on "clinical research funding", results from selected countries are presented and discussed. RESULTS: The amount invested was R$ 140 million. The largest number of projects supported "basic biomedical research", while the highest amounts invested were in "clinical trials" and "infrastructure support". The southeastern region had the greatest proportion of projects and financial resources. In some respects, Brazil is ahead of other BRICS countries (Russia, India, China and South Africa, especially with regard to establishing a National Clinical Research Network. CONCLUSION: The Ministry of Health ensured investments to encourage clinical research in Brazil and contributed towards promoting cohesion between investigators, health policies and the healthcare industrial production complex.

  3. Executable Design Models for a Pervasive Healthcare Middleware System

    DEFF Research Database (Denmark)

    Jørgensen, Jens Bæk; Christensen, Søren

    2002-01-01

     UML is applied in the design of a pervasive healthcare middleware system for the hospitals in Aarhus County, Denmark. It works well for the modelling of static aspects of the system, but with respect to describing the behaviour, UML is not sufficient. This paper explains why and, as a remedy......, suggests to supplement the UML models with behaviour descriptions in the modelling language Coloured Petri Nets, CPN. CPN models are executable and fine-grained, and a combined use of UML and CPN thus supports design-time investigation of the detailed behaviour of system components. In this way...

  4. LiDAR Vegetation Investigation and Signature Analysis System (LVISA)

    Science.gov (United States)

    Höfle, Bernhard; Koenig, Kristina; Griesbaum, Luisa; Kiefer, Andreas; Hämmerle, Martin; Eitel, Jan; Koma, Zsófia

    2015-04-01

    lacks behind. We propose a novel concept, the LiDAR Vegetation Investigation and Signature Analysis System (LVISA), which shall enhance sharing of i) reference datasets of single vegetation objects with rich reference data (e.g., plant species, basic plant morphometric information) and ii) approaches for information extraction (e.g., single tree detection, tree species classification based on waveform LiDAR features). We will build an extensive LiDAR data repository for supporting the development and benchmarking of LiDAR-based object information extraction. The LiDAR Vegetation Investigation and Signature Analysis System (LVISA) uses international web service standards (Open Geospatial Consortium, OGC) for geospatial data access and also analysis (e.g., OGC Web Processing Services). This will allow the research community identifying plant object specific vegetation features from LiDAR data, while accounting for differences in LiDAR systems (e.g., beam divergence), settings (e.g., point spacing), and calibration techniques. It is the goal of LVISA to develop generic 3D information extraction approaches, which can be seamlessly transferred to other datasets, timestamps and also extraction tasks. The current prototype of LVISA can be visited and tested online via http://uni-heidelberg.de/lvisa. Video tutorials provide a quick overview and entry into the functionality of LVISA. We will present the current advances of LVISA and we will highlight future research and extension of LVISA, such as integrating low-cost LiDAR data and datasets acquired by highly temporal scanning of vegetation (e.g., continuous measurements). Everybody is invited to join the LVISA development and share datasets and analysis approaches in an interoperable way via the web-based LVISA geoportal.

  5. Service systems concepts, modeling, and programming

    CERN Document Server

    Cardoso, Jorge; Poels, Geert

    2014-01-01

    This SpringerBrief explores the internal workings of service systems. The authors propose a lightweight semantic model for an effective representation to capture the essence of service systems. Key topics include modeling frameworks, service descriptions and linked data, creating service instances, tool support, and applications in enterprises.Previous books on service system modeling and various streams of scientific developments used an external perspective to describe how systems can be integrated. This brief introduces the concept of white-box service system modeling as an approach to mo

  6. Analytical investigation of low temperature lift energy conversion systems with renewable energy source

    International Nuclear Information System (INIS)

    Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard

    2014-01-01

    The efficiency of the renewable energy powered energy conversion system is typically low due to its moderate heat source temperature. Therefore, improving its energy efficiency is essential. In this study, the performance of the energy conversion system with renewable energy source was theoretically investigated in order to explore its design aspect. For this purpose, a computer model of n-stage low temperature lift energy conversion (LTLEC) system was developed. The results showed that under given operating conditions such as temperatures and mass flow rates of heat source and heat sink fluids the unit power generation of the system increased with the number of stage, and it became saturated when the number of staging reached four. Investigation of several possible working fluids for the optimum stage LTLEC system revealed that ethanol could be an alternative to ammonia. The heat exchanger effectiveness is a critical factor on the system performance. The power generation was increased by 7.83% for the evaporator and 9.94% for the condenser with 10% increase of heat exchanger effectiveness. When these low temperature source fluids are applied to the LTLEC system, the heat exchanger performance would be very critical and it has to be designed accordingly. - Highlights: •Energy conversion system with renewable energy is analytically investigated. •A model of multi-stage low temperature lift energy conversion systems was developed. •The system performance increases as the stage number is increased. •The unit power generation is increased with increase of HX effectiveness. •Ethanol is found to be a good alternative to ammonia

  7. Building Finite Element Models to Investigate Zebrafish Jaw Biomechanics.

    Science.gov (United States)

    Brunt, Lucy H; Roddy, Karen A; Rayfield, Emily J; Hammond, Chrissy L

    2016-12-03

    Skeletal morphogenesis occurs through tightly regulated cell behaviors during development; many cell types alter their behavior in response to mechanical strain. Skeletal joints are subjected to dynamic mechanical loading. Finite element analysis (FEA) is a computational method, frequently used in engineering that can predict how a material or structure will respond to mechanical input. By dividing a whole system (in this case the zebrafish jaw skeleton) into a mesh of smaller 'finite elements', FEA can be used to calculate the mechanical response of the structure to external loads. The results can be visualized in many ways including as a 'heat map' showing the position of maximum and minimum principal strains (a positive principal strain indicates tension while a negative indicates compression. The maximum and minimum refer the largest and smallest strain). These can be used to identify which regions of the jaw and therefore which cells are likely to be under particularly high tensional or compressional loads during jaw movement and can therefore be used to identify relationships between mechanical strain and cell behavior. This protocol describes the steps to generate Finite Element models from confocal image data on the musculoskeletal system, using the zebrafish lower jaw as a practical example. The protocol leads the reader through a series of steps: 1) staining of the musculoskeletal components, 2) imaging the musculoskeletal components, 3) building a 3 dimensional (3D) surface, 4) generating a mesh of Finite Elements, 5) solving the FEA and finally 6) validating the results by comparison to real displacements seen in movements of the fish jaw.

  8. Numerical Simulation and Investigation of System Parameters of Sonochemical Process

    Directory of Open Access Journals (Sweden)

    Sankar Chakma

    2013-01-01

    Full Text Available This paper presents the effects of various parameters that significantly affect the cavitation. In this study, three types of liquid mediums with different physicochemical properties were considered as the cavitation medium. The effects of various operating parameters such as temperature, pressure, initial bubble radius, dissolved gas content and so forth, were investigated in detail. The simulation results of cavitation bubble dynamics model showed a very interesting link among these parameters for production of oxidizing species. The formation of •OH radical and H2O2 is considered as the results of main effects of sonochemical process. Simulation results of radial motion of cavitation bubble dynamics revealed that bubble with small initial radius gives higher sonochemical effects. This is due to the bubble with small radius can undergo many acoustic cycles before reaching its critical radius when it collapses and produces higher temperature and pressure inside the bubble. On the other hand, due to the low surface tension and high vapor pressure, organic solvents are not suitable for sonochemical reactions.

  9. On Verification Modelling of Embedded Systems

    NARCIS (Netherlands)

    Brinksma, Hendrik; Mader, Angelika H.

    Computer-aided verification of embedded systems hinges on the availability of good verification models of the systems at hand. Such models must be much simpler than full design models or specifications to be of practical value, because of the unavoidable combinatorial complexities in the

  10. Balmorel open source energy system model

    DEFF Research Database (Denmark)

    Wiese, Frauke; Bramstoft, Rasmus; Koduvere, Hardi

    2018-01-01

    As the world progresses towards a cleaner energy future with more variable renewable energy sources, energy system models are required to deal with new challenges. This article describes design, development and applications of the open source energy system model Balmorel, which is a result of a l...... transport of local biomass as part of the optimisation and speeding up the model....

  11. Modeling, Control and Coordination of Helicopter Systems

    CERN Document Server

    Ren, Beibei; Chen, Chang; Fua, Cheng-Heng; Lee, Tong Heng

    2012-01-01

    Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved. This book also: Presents a complete picture of modeling, control and coordination for helicopter systems Provides a modeling platform for a general class of ro...

  12. Systems Biology—Biomedical Modeling

    OpenAIRE

    Sobie, Eric A.; Lee, Young-Seon; Jenkins, Sherry L.; Iyengar, Ravi

    2011-01-01

    Because of the complexity inherent in biological systems, many researchers frequently rely on a combination of global analysis and computational approaches to gain insight into both (i) how interacting components can produce complex system behaviors, and (ii) how changes in conditions may alter these behaviors. Because the biological details of a particular system are generally not taught along with the quantitative approaches that enable hypothesis generation and analysis of the system, we d...

  13. Investigation of Effectiveness of Order Review and Release Models in Make to Order Supply Chain

    Directory of Open Access Journals (Sweden)

    Kundu Kaustav

    2016-01-01

    Full Text Available Nowadays customisation becomes more common due to vast requirement from the customers for which industries are trying to use make-to-order (MTO strategy. Due to high variation in the process, workload control models are extensively used for jobshop companies which usually adapt MTO strategy. Some authors tried to implement workload control models, order review and release systems, in non-repetitive manufacturing companies, where there is a dominant flow in production. Those models are better in shop floor but their performances are never been investigated in high variation situations like MTO supply chain. This paper starts with the introduction of particular issues in MTO companies and a general overview of order review and release systems widely used in the industries. Two order review and release systems, the Limited and Balanced models, particularly suitable for flow shop system are applied to MTO supply chain, where the processing times are difficult to estimate due to high variation. Simulation results show that the Balanced model performs much better than the Limited model if the processing times can be estimated preciously.

  14. Modeling and simulation of systems using Matlab and Simulink

    CERN Document Server

    Chaturvedi, Devendra K

    2009-01-01

    Introduction to SystemsSystemClassification of SystemsLinear SystemsTime-Varying vs. Time-Invariant Systems Lumped vs. Distributed Parameter SystemsContinuous- and Discrete-Time Systems Deterministic vs. Stochastic Systems Hard and Soft Systems Analysis of Systems Synthesis of Systems Introduction to System Philosophy System Thinking Large and Complex Applied System Engineering: A Generic ModelingSystems ModelingIntroduction Need of System Modeling Modeling Methods for Complex Systems Classification of ModelsCharacteristics of Models ModelingMathematical Modeling of Physical SystemsFormulation of State Space Model of SystemsPhysical Systems Theory System Components and Interconnections Computation of Parameters of a Component Single Port and Multiport Systems Techniques of System Analysis Basics of Linear Graph Theoretic ApproachFormulation of System Model for Conceptual SystemFormulation System Model for Physical SystemsTopological RestrictionsDevelopment of State Model of Degenerative SystemSolution of Stat...

  15. Modelling and Verification of Relay Interlocking Systems

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Bliguet, Marie Le; Kjær, Andreas

    2010-01-01

    This paper describes how relay interlocking systems as used by the Danish railways can be formally modelled and verified. Such systems are documented by circuit diagrams describing their static layout. It is explained how to derive a state transition system model for the dynamic behaviour of a re...

  16. Compositional Modelling of Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Strubbe, S.N.

    2005-01-01

    In this thesis we present a modelling framework for compositional modelling of stochastic hybrid systems. Hybrid systems consist of a combination of continuous and discrete dynamics. The state space of a hybrid system is hybrid in the sense that it consists of a continuous component and a discrete

  17. INVESTIGATION OF THE DRAWBACKS OF THE CURRENT NOTAM SYSTEM

    Directory of Open Access Journals (Sweden)

    Mykola Bogunenko

    2013-10-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 The article deals with the analysis of the current NOTAM system, investigation of the factors that limit the NOTAM format, analysis of such drawbacks as human interpretation, information overload by the end use, geographical inaccuracy, not-self contained and hidden applicability /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Обычная таблица"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  18. Microscale methods to investigate and manipulate multispecies biological systems

    Science.gov (United States)

    Fong, Erika Jo

    This thesis details the development of a continuous perfusion platform capable of more closely mimicking in vivo cell-virus dynamics, while surpassing the experimental control and flexibility of standard cell culture. First, a microfluidic flow through acoustic device is optimized to enable efficient and controllable separation of cells and viruses. Repeatable isolation of cell and virus species is demonstrated with both a well-characterized virus, Dengue Virus (DENV), and the novel Golden Gate Virus. Next, a platform is built around this device to enable controllable, automated, continuous cell culture. Beads are used to assess system performance and optimize operation. Subsequently, the platform is used to culture both murine hybridoma (4G2) and human monocyte (THP-1) cell lines for over one month, and demonstrate the ability to manipulate population dynamics. Finally, we use the platform to establish a multispecies culture with THP-1 cells and Sindbis Virus (SINV). This work integrates distinct engineering feats to create a platform capable of enhancing existing cell virus studies and opening the door to a variety of high-impact investigations. (Abstract shortened by ProQuest.).

  19. Investigating Mesoscale Convective Systems and their Predictability Using Machine Learning

    Science.gov (United States)

    Daher, H.; Duffy, D.; Bowen, M. K.

    2016-12-01

    A mesoscale convective system (MCS) is a thunderstorm region that lasts several hours long and forms near weather fronts and can often develop into tornadoes. Here we seek to answer the question of whether these tornadoes are "predictable" by looking for a defining characteristic(s) separating MCSs that evolve into tornadoes versus those that do not. Using NASA's Modern Era Retrospective-analysis for Research and Applications 2 reanalysis data (M2R12K), we apply several state of the art machine learning techniques to investigate this question. The spatial region examined in this experiment is Tornado Alley in the United States over the peak tornado months. A database containing select variables from M2R12K is created using PostgreSQL. This database is then analyzed using machine learning methods such as Symbolic Aggregate approXimation (SAX) and DBSCAN (an unsupervised density-based data clustering algorithm). The incentive behind using these methods is to mathematically define a MCS so that association rule mining techniques can be used to uncover some sort of signal or teleconnection that will help us forecast which MCSs will result in tornadoes and therefore give society more time to prepare and in turn reduce casualties and destruction.

  20. Models of complex attitude systems

    DEFF Research Database (Denmark)

    Sørensen, Bjarne Taulo

    Existing research on public attitudes towards agricultural production systems is largely descriptive, abstracting from the processes through which members of the general public generate their evaluations of such systems. The present paper adopts a systems perspective on such evaluations, understa......Existing research on public attitudes towards agricultural production systems is largely descriptive, abstracting from the processes through which members of the general public generate their evaluations of such systems. The present paper adopts a systems perspective on such evaluations......, understanding them as embedded into a wider attitude system that consists of attitudes towards objects of different abstraction levels, ranging from personal value orientations over general socio-political attitudes to evaluations of specific characteristics of agricultural production systems. It is assumed...... that evaluative affect propagates through the system in such a way that the system becomes evaluatively consistent and operates as a schema for the generation of evaluative judgments. In the empirical part of the paper, the causal structure of an attitude system from which people derive their evaluations of pork...

  1. Investigation of Multicritical Phenomena in ANNNI Model by Monte Carlo Methods

    Directory of Open Access Journals (Sweden)

    A. K. Murtazaev

    2012-01-01

    Full Text Available The anisotropic Ising model with competing interactions is investigated in wide temperature range and |J1/J| parameters by means of Monte Carlo methods. Static critical exponents of the magnetization, susceptibility, heat capacity, and correlation radius are calculated in the neighborhood of Lifshitz point. According to obtained results, a phase diagram is plotted, the coordinates of Lifshitz point are defined, and a character of multicritical behavior of the system is detected.

  2. Experimental investigation of lateral forces induced by flow through model labyrinth glands

    Science.gov (United States)

    Leong, Y. M. M. S.; Brown, R. D.

    1984-01-01

    The lateral forces induced by flow through model labyrinth glands were investigated. Circumferential pressure distributions, lateral forces and stiffness coefficients data obtained are discussed. The force system is represented as a negative spring and a tangential force orthogonal to eccentricity. The magnitude of these forces are dependent on eccentricity, entry swirl, rotor peripheral velocity and seal size. A pressure equalization chamber at midgland tests should in significantly reduced forces and stiffness coefficients.

  3. Modeling fuel cells in integrated multi-energy systems

    NARCIS (Netherlands)

    Gabriellissx, Paolo; Gazzani, Matteo; Mazzotti, Marco

    2017-01-01

    This contribution investigates how different technology modeling methodologies affect the design of decentralized multi-energy systems, especially when fuel cell and energy storage are considered. First, thermoelectric models based on a first-principle approach are implemented to determine the

  4. Modeling Control Situations in Power System Operations

    DEFF Research Database (Denmark)

    Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

    2010-01-01

    Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...

  5. Coupling geophysical investigation with hydrothermal modeling to constrain the enthalpy classification of a potential geothermal resource.

    Science.gov (United States)

    White, Jeremy T.; Karakhanian, Arkadi; Connor, Chuck; Connor, Laura; Hughes, Joseph D.; Malservisi, Rocco; Wetmore, Paul

    2015-01-01

    An appreciable challenge in volcanology and geothermal resource development is to understand the relationships between volcanic systems and low-enthalpy geothermal resources. The enthalpy of an undeveloped geothermal resource in the Karckar region of Armenia is investigated by coupling geophysical and hydrothermal modeling. The results of 3-dimensional inversion of gravity data provide key inputs into a hydrothermal circulation model of the system and associated hot springs, which is used to evaluate possible geothermal system configurations. Hydraulic and thermal properties are specified using maximum a priori estimates. Limited constraints provided by temperature data collected from an existing down-gradient borehole indicate that the geothermal system can most likely be classified as low-enthalpy and liquid dominated. We find the heat source for the system is likely cooling quartz monzonite intrusions in the shallow subsurface and that meteoric recharge in the pull-apart basin circulates to depth, rises along basin-bounding faults and discharges at the hot springs. While other combinations of subsurface properties and geothermal system configurations may fit the temperature distribution equally well, we demonstrate that the low-enthalpy system is reasonably explained based largely on interpretation of surface geophysical data and relatively simple models.

  6. Towards a community Earth System Model

    Science.gov (United States)

    Blackmon, M.

    2003-04-01

    The Community Climate System Model, version 2 (CCSM2), was released in June 2002. CCSM2 has several new components and features, which I will discuss briefly. I will also show a few results from a multi-century equilibrium run with this model, emphasizing the improvements over the earlier simulation using the original CSM. A few flaws and inadequacies in CCSM2 have been identified. I will also discuss briefly work underway to improve the model and present results, if available. CCSM2, with improvements, will be the basis for the development of a Community Earth System Model (CESM). The highest priority for expansion of the model involves incorporation of biogeosciences into the coupled model system, with emphasis given to the carbon, nitrogen and iron cycles. The overall goal of the biogeosciences project within CESM is to understand the regulation of planetary energetics, planetary ecology, and planetary metabolism through exchanges of energy, momentum, and materials among atmosphere, land, and ocean, and the response of the climate system through these processes to changes in land cover and land use. In particular, this research addresses how biogeochemical coupling of carbon, nitrogen, and iron cycles affects climate and how human perturbations of these cycles alter climate. To accomplish these goals, the Community Land Model, the land component of CCSM2, is being developed to include river routing, carbon and nitrogen cycles, emissions of mineral aerosols and biogenic volatile organic compounds, dry deposition of various gases, and vegetation dynamics. The carbon and nitrogen cycles are being implemented using parameterizations developed as part of a state-of-the-art ecosystem biogeochemistry model. The primary goal of this research is to provide an accurate net flux of CO2 between the land and the atmosphere so that CESM can be used to study the dynamics of the coupled climate-carbon system. Emissions of biogenic volatile organic compounds are also based on a

  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. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    International Nuclear Information System (INIS)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-01

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  10. Investigation of modern methods of probalistic sensitivity analysis of final repository performance assessment models (MOSEL)

    Energy Technology Data Exchange (ETDEWEB)

    Spiessl, Sabine; Becker, Dirk-Alexander

    2017-06-15

    Sensitivity analysis is a mathematical means for analysing the sensitivities of a computational model to variations of its input parameters. Thus, it is a tool for managing parameter uncertainties. It is often performed probabilistically as global sensitivity analysis, running the model a large number of times with different parameter value combinations. Going along with the increase of computer capabilities, global sensitivity analysis has been a field of mathematical research for some decades. In the field of final repository modelling, probabilistic analysis is regarded a key element of a modern safety case. An appropriate uncertainty and sensitivity analysis can help identify parameters that need further dedicated research to reduce the overall uncertainty, generally leads to better system understanding and can thus contribute to building confidence in the models. The purpose of the project described here was to systematically investigate different numerical and graphical techniques of sensitivity analysis with typical repository models, which produce a distinctly right-skewed and tailed output distribution and can exhibit a highly nonlinear, non-monotonic or even non-continuous behaviour. For the investigations presented here, three test models were defined that describe generic, but typical repository systems. A number of numerical and graphical sensitivity analysis methods were selected for investigation and, in part, modified or adapted. Different sampling methods were applied to produce various parameter samples of different sizes and many individual runs with the test models were performed. The results were evaluated with the different methods of sensitivity analysis. On this basis the methods were compared and assessed. This report gives an overview of the background and the applied methods. The results obtained for three typical test models are presented and explained; conclusions in view of practical applications are drawn. At the end, a recommendation

  11. Bedrock Hydrogeology-Groundwater flow modelling. Site investigation SFR

    International Nuclear Information System (INIS)

    Oehman, Johan; Follin, Sven; Oden, Magnus

    2013-05-01

    The hydrogeological model developed for the SFR extension project (PSU) consists of 40 geologically modelled deformation zones (DZ) and 8 sub-horizontal structural-hydraulic features, called SBAstructures, not defined in the geological model. However, some of the SBA-structures coincide with what is defined as unresolved possible deformation zones (Unresolved PDZ) in the geological modelling. In addition, the hydrogeological model consists of a stochastic discrete fracture network (DFN) model intended for the less fractured rock mass volumes (fracture domains) between the zones and the SBA-structures, and a stochastic fracture model intended to handle remaining Unresolved PDZs in the geological modelling not modelled as SBA-structures in the hydrogeological modelling. The four structural components of the bedrock in the hydrogeological model, i.e. DZ, SBA, Unresolved PDZ and DFN, are assigned hydraulic properties in the hydrogeological model based on the transmissivities interpreted from single-hole hydraulic tests. The main objective of the present work is to present the characteristics of the hydrogeological model with regard to the needs of the forthcoming safety assessment SR-PSU. In concrete words, simulated data are compared with measured data, i.e. hydraulic heads in boreholes and tunnel inflow to the existing repository (SFR). The calculations suggest that the available data for flow model calibration cannot be used to motivate a substantial adjustment of the initial hydraulic parameterisation (assignment of hydraulic properties) of the hydrogeological model. It is suggested that uncertainties in the hydrogeological model are studied in the safety assessment SR-PSU by means of a large number of calculation cases. These should address hydraulic heterogeneity of deterministic structures (DZ and SBA) and realisations of stochastic fractures/fracture networks (Unresolved PDZ and DFN) within the entire SFR Regional model domain

  12. Bedrock Hydrogeology - Groundwater flow modelling. Site investigation SFR

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Johan [Geosigma AB, Uppsala (Sweden); Follin, Sven [SF GeoLogic AB, Taeby (Sweden); Oden, Magnus [SKB, Stockholm (Sweden)

    2013-05-15

    The hydrogeological model developed for the SFR extension project (PSU) consists of 40 geologically modelled deformation zones (DZ) and 8 sub-horizontal structural-hydraulic features, called SBAstructures, not defined in the geological model. However, some of the SBA-structures coincide with what is defined as unresolved possible deformation zones (Unresolved PDZ) in the geological modelling. In addition, the hydrogeological model consists of a stochastic discrete fracture network (DFN) model intended for the less fractured rock mass volumes (fracture domains) between the zones and the SBA-structures, and a stochastic fracture model intended to handle remaining Unresolved PDZs in the geological modelling not modelled as SBA-structures in the hydrogeological modelling. The four structural components of the bedrock in the hydrogeological model, i.e. DZ, SBA, Unresolved PDZ and DFN, are assigned hydraulic properties in the hydrogeological model based on the transmissivities interpreted from single-hole hydraulic tests. The main objective of the present work is to present the characteristics of the hydrogeological model with regard to the needs of the forthcoming safety assessment SR-PSU. In concrete words, simulated data are compared with measured data, i.e. hydraulic heads in boreholes and tunnel inflow to the existing repository (SFR). The calculations suggest that the available data for flow model calibration cannot be used to motivate a substantial adjustment of the initial hydraulic parameterisation (assignment of hydraulic properties) of the hydrogeological model. It is suggested that uncertainties in the hydrogeological model are studied in the safety assessment SR-PSU by means of a large number of calculation cases. These should address hydraulic heterogeneity of deterministic structures (DZ and SBA) and realisations of stochastic fractures/fracture networks (Unresolved PDZ and DFN) within the entire SFR Regional model domain.

  13. Holonic Models for Traffic Control Systems

    Science.gov (United States)

    Ciufudean, Calin; Filote, Constantin

    This paper proposes a new time-placed net model for traffic control systems, respectively railway control traffic systems. This model can be interpreted as a holonic one, and contains three modules: Transport Planning Module, Transport Control Module and Priority Control Module. For railway traffic systems we introduce a strategy in a timed-place Petri net model to solve collision and traffic jam problems.

  14. Hydrological modeling in forested systems

    Science.gov (United States)

    H.E. Golden; G.R. Evenson; S. Tian; Devendra Amatya; Ge Sun

    2015-01-01

    Characterizing and quantifying interactions among components of the forest hydrological cycle is complex and usually requires a combination of field monitoring and modelling approaches (Weiler and McDonnell, 2004; National Research Council, 2008). Models are important tools for testing hypotheses, understanding hydrological processes and synthesizing experimental data...

  15. The Terrestrial Investigation Model: A probabilistic risk assessment model for birds exposed to pesticides

    Science.gov (United States)

    One of the major recommendations of the National Academy of Science to the USEPA, NMFS and USFWS was to utilize probabilistic methods when assessing the risks of pesticides to federally listed endangered and threatened species. The Terrestrial Investigation Model (TIM, version 3....

  16. The ABC model: a non-hydrostatic toy model for use in convective-scale data assimilation investigations

    Science.gov (United States)

    Petrie, Ruth Elizabeth; Bannister, Ross Noel; Priestley Cullen, Michael John

    2017-12-01

    In developing methods for convective-scale data assimilation (DA), it is necessary to consider the full range of motions governed by the compressible Navier-Stokes equations (including non-hydrostatic and ageostrophic flow). These equations describe motion on a wide range of timescales with non-linear coupling. For the purpose of developing new DA techniques that suit the convective-scale problem, it is helpful to use so-called toy models that are easy to run and contain the same types of motion as the full equation set. Such a model needs to permit hydrostatic and geostrophic balance at large scales but allow imbalance at small scales, and in particular, it needs to exhibit intermittent convection-like behaviour. Existing toy models are not always sufficient for investigating these issues. A simplified system of intermediate complexity derived from the Euler equations is presented, which supports dispersive gravity and acoustic modes. In this system, the separation of timescales can be greatly reduced by changing the physical parameters. Unlike in existing toy models, this allows the acoustic modes to be treated explicitly and hence inexpensively. In addition, the non-linear coupling induced by the equation of state is simplified. This means that the gravity and acoustic modes are less coupled than in conventional models. A vertical slice formulation is used which contains only dry dynamics. The model is shown to give physically reasonable results, and convective behaviour is generated by localised compressible effects. This model provides an affordable and flexible framework within which some of the complex issues of convective-scale DA can later be investigated. The model is called the ABC model after the three tunable parameters introduced: A (the pure gravity wave frequency), B (the modulation of the divergent term in the continuity equation), and C (defining the compressibility).

  17. Investigation of stress–strain models for confined high strength ...

    Indian Academy of Sciences (India)

    The ascending branch of stress–strain curves depended on the ratio of confinement reinforcement was similar to the modified Kent–Park model and the descending branch similar to the Nagashima model. Keywords. High strength concrete; confined concrete; stress–strain models; ductility toughness. 1. Introduction.

  18. FINESSE: Field Investigations to Enable Solar System Science and Exploration

    Science.gov (United States)

    Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

    2015-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

  19. Life-Cycle Models for Survivable Systems

    National Research Council Canada - National Science Library

    Linger, Richard

    2002-01-01

    .... Current software development life-cycle models are not focused on creating survivable systems, and exhibit shortcomings when the goal is to develop systems with a high degree of assurance of survivability...

  20. Model Updating Nonlinear System Identification Toolbox Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology (ZONA) proposes to develop an enhanced model updating nonlinear system identification (MUNSID) methodology that utilizes flight data with...

  1. PENERAPAN MODEL PEMBELAJARAN GROUP INVESTIGATION (GI UNTUK MENINGKATKAN AKTIVITAS DAN HASIL BELAJAR SISTEM PENGAPIAN KONVENSIONAL

    Directory of Open Access Journals (Sweden)

    Ahfid Husni Mubarok

    2016-06-01

    Full Text Available The aim of this research to determine the increase in activity and learning outcomes conventional ignition system by applying the learning model of Group Investigation (GI. The hypothesis in this research is application of Group Investigation (GI learning model’s can increase the activity and learning outcomes conventional ignition system. The research is a Classroom Action Research (CAR conducted collaboratively between teachers and researches. The subjects in this study is 20 students from class TKR of SMK, while the object of this research is the application of Group Investigation learning model’s (GI to increase the activity and student learning outcomes in conventional ignition system subjects. The experiment was conducted with three (3 cycles. Data collection techniques using observation, testing and documentation. Data were analyzed using quantitative description of the statistical formula. Results of this research by applying the Group Investigation learning model’s (GI showed the presence of increasing activity and learning outcomes conventional ignition system in every cycle. This is indicated by: 1. The increase of learning outcomes was showed by percentage of learning activity more than (≥ enough, before action only 25% increased by 22,4% into 47,4% after doing first cycles. When doing second cycles increased by 10,5% into 63,2% and third cycles increased by 10,5% into 73,7%. 2. Another increase was showed by learning outcomes of students who passed, from learning outcomes before action only 40% and after doing first cycles increased by 12,6% to 52,6%. Then second cycles increased by 8,5% into 61,1% and third cycles increased by 17,8% into 78,9%. From the above data it can be conclude by applying the learning model of Group Investigation (GI on the subjects of conventional ignition system  can increase the activity and learning outcomes, in line with the hypotesis of this action research

  2. Investigation clogging dynamic of permeable pavement systems using embedded sensors

    Science.gov (United States)

    Razzaghmanesh, Mostafa; Borst, Michael

    2018-02-01

    Permeable pavement is a stormwater control measure commonly selected in both new and retrofit applications. However, there is limited information about the clogging mechanism of these systems that effects the infiltration. A permeable pavement site located at the Seitz Elementary School, on Fort Riley, Kansas was selected for this study. An 80-space parking lot was built behind the school as part of an EPA collaboration with the U.S. Army. The parking lot design includes a permeable interlocking concrete pavement section along the downgradient edge. This study monitored the clogging progress of the pavement section using twelve water content reflectometers and three buried tipping bucket rain gauges. This clogging dynamic investigation was divided into three stages namely pre-clogged, transitional, and clogged. Recorded initial relative water content of all three stages were significantly and negatively correlated to antecedent dry weather periods with stronger correlations during clogged conditions. The peak relative water content correlation with peak rainfall 10-min intensity was significant for the water content reflectometers located on the western edge away from the eastern edge; this correlation was strongest during transition stage. Once clogged, rainfall measurements no longer correlated with the buried tipping bucket rain gauges. Both water content reflectometers and buried tipping bucket rain gauges showed the progress of surface clogging. For every 6 mm of rain, clogging advanced 1 mm across the surface. The results generally support the hypothesis that the clogging progresses from the upgradient to the downgradient edge. The magnitude of the contributing drainage area and rainfall characteristics are effective factors on rate and progression of clogging.

  3. Technical know-how for the investigation and modelling of topographic evolution for site characterisation - 59171

    International Nuclear Information System (INIS)

    Doke, Ryosuke; Yasue, Ken-ichi; Niizato, Tadafumi; Nakayasu, Akio

    2012-01-01

    Geological hazard assessments are being used to make important decisions relevant to nuclear facilities such as a repository for deep geological disposal of high-level radioactive waste. With respect to such repositories, topographic evolution is a key issue for description of the long-term evolution of a groundwater flow characteristics in time spans of tens to hundreds of thousands of years. The construction of topographic evolution models is complex, involving tacit knowledge and working processes. Therefore, it is important to externalise, that is to explicitly present the tacit knowledge and decision-making processes used by experts in the model building unambiguously, with thorough documentation and to provide key knowledge to support planning and implementation of investigations. In this study, documentation of the technical know-how used for the construction of a topographic evolution model is demonstrated. The process followed in the construction of the model is illustrated using task-flow logic diagrams; the process involves four main tasks with several sub-tasks. The task-flow followed for an investigation to estimate uplift rates linked to the task-flow for the modelling of topographic evolution is also illustrated. In addition, the decision-making processes in the investigation are expressed in logical IF-THEN format for each task. Based on the documented technical know-how, an IT-based Expert System was constructed. In future work, it is necessary to analyse the knowledge, including the management of uncertainties in the modelling and investigations, and to integrate fundamental ideas for managing uncertainties with expert system. (authors)

  4. An expert system for dispersion model interpretation

    International Nuclear Information System (INIS)

    Skyllingstad, E.D.; Ramsdell, J.V.

    1988-10-01

    A prototype expert system designed to diagnose dispersion model uncertainty is described in this paper with application to a puff transport model. The system obtains qualitative information from the model user and through an expert-derived knowledge base, performs a rating of the current simulation. These results can then be used in combination with dispersion model output for deciding appropriate evacuation measures. Ultimately, the goal of this work is to develop an expert system that may be operated accurately by an individual uneducated in meteorology or dispersion modeling. 5 refs., 3 figs

  5. Semantic models for adaptive interactive systems

    CERN Document Server

    Hussein, Tim; Lukosch, Stephan; Ziegler, Jürgen; Calvary, Gaëlle

    2013-01-01

    Providing insights into methodologies for designing adaptive systems based on semantic data, and introducing semantic models that can be used for building interactive systems, this book showcases many of the applications made possible by the use of semantic models.Ontologies may enhance the functional coverage of an interactive system as well as its visualization and interaction capabilities in various ways. Semantic models can also contribute to bridging gaps; for example, between user models, context-aware interfaces, and model-driven UI generation. There is considerable potential for using

  6. Models of the venous system

    DEFF Research Database (Denmark)

    Mehlsen, J

    2000-01-01

    of the venous system require at least three elements: a resistor, a capacitor and an inductor, with the latter being of more importance in the venous than in the arterial system. Non-linearities must be considered in pressure/flow relations in the small venules, during venous collapse, or low flow conditions...

  7. Stochastic Models of Polymer Systems

    Science.gov (United States)

    2016-01-01

    published in non-peer-reviewed journals (N/A for none) The dynamics of stochastic gradient algorithms (submitted); Noisy Hegselmann- Krause Systems...algorithms for big data applications. (2) We studied stochastic dynamics of polymer systems in the mean field limit. (3) We studied noisy Hegselmann- Krause

  8. Magnetic and resonant X-ray scattering investigations of strongly correlated electron systems

    International Nuclear Information System (INIS)

    Paolasini, L.; Bergevin, F. de

    2008-01-01

    Resonant X-ray scattering is a method which combines high-Q resolution X-ray elastic diffraction and atomic core-hole spectroscopy for investigating electronic and magnetic long-range ordered structures in condensed matter. During recent years the development of theoretical models to describe resonant X-ray scattering amplitudes and the evolution of experimental techniques, which include the control and analysis of linear photon polarization and the introduction of extreme environment conditions such as low temperatures, high magnetic field and high pressures, have opened a new field of investigation in the domain of strongly correlated electron systems. (authors)

  9. Switching model photovoltaic pumping system

    Science.gov (United States)

    Anis, Wagdy R.; Abdul-Sadek Nour, M.

    Photovoltaic (PV) pumping systems are widely used due to their simplicity, high reliability and low cost. A directly-coupled PV pumping system is the most reliable and least-cost PV system. The d.c. motor-pump group is not, however, working at its optimum operating point. A battery buffered PV pumping system introduces a battery between the PV array and the d.c. motor-pump group to ensure that the motor-pump group is operating at its optimum point. The size of the battery storage depends on system economics. If the battery is fully charged while solar radiation is available, the battery will discharge through the load while the PV array is disconnected. Hence, a power loss takes place. To overcome the above mentioned difficulty, a switched mode PV pumping is proposed. When solar radiation is available and the battery is fully charged, the battery is disconnected and the d.c. motor-pump group is directly coupled to the PV array. To avoid excessive operating voltage for the motor, a part of the PV array is switched off to reduce the voltage. As a result, the energy loss is significantly eliminated. Detailed analysis of the proposed system shows that the discharged water increases by about 10% when compared with a conventional battery-buffered system. The system transient performance just after the switching moment shows that the system returns to a steady state in short period. The variations in the system parameters lie within 1% of the rated values.

  10. Multiple system modelling of waste management

    International Nuclear Information System (INIS)

    Eriksson, Ola; Bisaillon, Mattias

    2011-01-01

    Highlights: → Linking of models will provide a more complete, correct and credible picture of the systems. → The linking procedure is easy to perform and also leads to activation of project partners. → The simulation procedure is a bit more complicated and calls for the ability to run both models. - Abstract: Due to increased environmental awareness, planning and performance of waste management has become more and more complex. Therefore waste management has early been subject to different types of modelling. Another field with long experience of modelling and systems perspective is energy systems. The two modelling traditions have developed side by side, but so far there are very few attempts to combine them. Waste management systems can be linked together with energy systems through incineration plants. The models for waste management can be modelled on a quite detailed level whereas surrounding systems are modelled in a more simplistic way. This is a problem, as previous studies have shown that assumptions on the surrounding system often tend to be important for the conclusions. In this paper it is shown how two models, one for the district heating system (MARTES) and another one for the waste management system (ORWARE), can be linked together. The strengths and weaknesses with model linking are discussed when compared to simplistic assumptions on effects in the energy and waste management systems. It is concluded that the linking of models will provide a more complete, correct and credible picture of the consequences of different simultaneous changes in the systems. The linking procedure is easy to perform and also leads to activation of project partners. However, the simulation procedure is a bit more complicated and calls for the ability to run both models.

  11. Investigating actinide compounds within a hybrid MCSCF-DFT model

    International Nuclear Information System (INIS)

    Fromager, E.; Jensen, H.J.A.; Wahlin, P.; Real, F.; Wahlgren, U.

    2007-01-01

    Complete text of publication follows: Investigations of actinide chemistry with quantum chemical methods still remain a complicated task since it requires an accurate and efficient treatment of the environment (crystal or solvent) as well as relativistic and electron correlation effects. Concerning the latter, the current correlated methods, based on either Density-Functional Theory (DFT) or Wave-Function Theory (WFT), have their advantages and drawbacks. On the one hand, Kohn-Sham DFT (KS-DFT) calculates the dynamic correlation quite accurately and at a fairly low computational cost. However, it does not treat adequately the static correlation, which is significant in some actinide compounds because of the near-degeneracy of the 5f orbitals: a first example is the bent geometry obtained in KS-DFT(B3LYP) for the neptunyl ion NpO 2 3+ , which is found to be linear within a Multi-Configurational Self-Consistent Field (MCSCF) model [1]. A second one is the stable and bent geometry obtained in KS-DFT(B3LYP) for the plutonyl ion PuO 2 4+ , which disintegrates at the MCSCF level [1]. On the other hand, WFT can describe the static correlation, using for example a MCSCF model, but then an important part of the dynamic correlation has to be neglected. This can be recovered with perturbation-theory based methods like for example CASPT2 or NEVPT2, but their computational complexity prevents large scale calculations. It is therefore of great interest to develop a hybrid MCSCF-DFT model which combines the best of both WFT and DFT approaches. The merge of WFT and DFT can be achieved by splitting the two-electron interaction into long-range and short-range parts [2]. The long-range part is then treated by WFT and the short-range part by DFT. We use the so-called 'erf' long-range interaction erf(μr 12 )/r 12 , which is based on the standard error function, and where μ is a free parameter which controls the long/short-range decomposition. The newly proposed recipe for the

  12. Modeling of power electronic systems with EMTP

    Science.gov (United States)

    Tam, Kwa-Sur; Dravid, Narayan V.

    1989-01-01

    In view of the potential impact of power electronics on power systems, there is need for a computer modeling/analysis tool to perform simulation studies on power systems with power electronic components as well as to educate engineering students about such systems. The modeling of the major power electronic components of the NASA Space Station Freedom Electric Power System is described along with ElectroMagnetic Transients Program (EMTP) and it is demonstrated that EMTP can serve as a very useful tool for teaching, design, analysis, and research in the area of power systems with power electronic components. EMTP modeling of power electronic circuits is described and simulation results are presented.

  13. Investigation of Brain Arterial Circle Malformations Using Electrical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2006-01-01

    Full Text Available The paper deals with the cerebral arterial system investigation by means of electrical modelling and simulations. The main attention is paid to the brain arterial circle malformations (stenoses and aneurysms and their determination and evaluation by computer-aided methods as tools of a non-invasive diagnostics. The compensation possibilities of brain arterial circle in case of presence of concrete arterial malformations are modelled and simulated. The simulation results of brain arteries blood pressures and volume flow velocities time dependences are presented and discussed under various health conditions.

  14. Network model of security system

    Directory of Open Access Journals (Sweden)

    Adamczyk Piotr

    2016-01-01

    Full Text Available The article presents the concept of building a network security model and its application in the process of risk analysis. It indicates the possibility of a new definition of the role of the network models in the safety analysis. Special attention was paid to the development of the use of an algorithm describing the process of identifying the assets, vulnerability and threats in a given context. The aim of the article is to present how this algorithm reduced the complexity of the problem by eliminating from the base model these components that have no links with others component and as a result and it was possible to build a real network model corresponding to reality.

  15. Numerical investigation into the existence of limit cycles in two-dimensional predator�prey systems

    Directory of Open Access Journals (Sweden)

    Quay van der Hoff

    2013-05-01

    Full Text Available There has been a surge of interest in developing and analysing models of interacting species in ecosystems, with specific interest in investigating the existence of limit cycles in systems describing the dynamics of these species. The original Lotka–Volterra model does not possess any limit cycles. In recent years this model has been modified to take disturbances into consideration and allow populations to return to their original numbers. By introducing logistic growth and a Holling Type II functional response to the traditional Lotka–Volterra-type models, it has been proven analytically that a unique, stable limit cycle exists. These proofs make use of Dulac functions, Liénard equations and invariant regions, relying on theory developed by Poincaré, Poincaré-Bendixson, Dulac and Liénard, and are generally perceived as difficult. Computer algebra systems are ideally suited to apply numerical methods to confirm or refute the analytical findings with respect to the existence of limit cycles in non-linear systems. In this paper a class of predator–prey models of a Gause type is used as the vehicle to illustrate the use of a simple, yet novel numerical algorithm. This algorithm confirms graphically the existence of at least one limit cycle that has analytically been proven to exist. Furthermore, adapted versions of the proposed algorithm may be applied to dynamic systems where it is difficult, if not impossible, to prove analytically the existence of limit cycles.

  16. Numerical Investigation of Startup Instabilities in Parallel-Channel Natural Circulation Boiling Systems

    Directory of Open Access Journals (Sweden)

    S. P. Lakshmanan

    2010-01-01

    Full Text Available The behaviour of a parallel-channel natural circulation boiling water reactor under a low-pressure low-power startup condition has been studied numerically (using RELAP5 and compared with its scaled model. The parallel-channel RELAP5 model is an extension of a single-channel model developed and validated with experimental results. Existence of in-phase and out-of-phase flashing instabilities in the parallel-channel systems is investigated through simulations under equal and unequal power boundary conditions in the channels. The effect of flow resistance on Type-I oscillations is explored. For nonidentical condition in the channels, the flow fluctuations in the parallel-channel systems are found to be out-of-phase.

  17. Modeling Adaptive Behavior for Systems Design

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1994-01-01

    Field studies in modern work systems and analysis of recent major accidents have pointed to a need for better models of the adaptive behavior of individuals and organizations operating in a dynamic and highly competitive environment. The paper presents a discussion of some key characteristics...... of the predictive models required for the design of work supports systems, that is,information systems serving as the human-work interface. Three basic issues are in focus: 1.) Some fundamental problems in analysis and modeling modern dynamic work systems caused by the adaptive nature of human behavior; 2.......) The basic difference between the models of system functions used in engineering and design and those evolving from basic research within the various academic disciplines and finally 3.) The models and methods required for closed-loop, feedback system design....

  18. Model-based version management system framework

    International Nuclear Information System (INIS)

    Mehmood, W.

    2016-01-01

    In this paper we present a model-based version management system. Version Management System (VMS) a branch of software configuration management (SCM) aims to provide a controlling mechanism for evolution of software artifacts created during software development process. Controlling the evolution requires many activities to perform, such as, construction and creation of versions, identification of differences between versions, conflict detection and merging. Traditional VMS systems are file-based and consider software systems as a set of text files. File based VMS systems are not adequate for performing software configuration management activities such as, version control on software artifacts produced in earlier phases of the software life cycle. New challenges of model differencing, merge, and evolution control arise while using models as central artifact. The goal of this work is to present a generic framework model-based VMS which can be used to overcome the problem of tradition file-based VMS systems and provide model versioning services. (author)

  19. Very Large System Dynamics Models - Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Leonard Malczynski

    2008-10-01

    This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

  20. Investigation of longitudinal control system for a small hydrofoil boat

    Science.gov (United States)

    Phillips, W. H.; Shaughnessy, J. D.

    1976-01-01

    An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

  1. Test-driven modeling of embedded systems

    DEFF Research Database (Denmark)

    Munck, Allan; Madsen, Jan

    2015-01-01

    To benefit maximally from model-based systems engineering (MBSE) trustworthy high quality models are required. From the software disciplines it is known that test-driven development (TDD) can significantly increase the quality of the products. Using a test-driven approach with MBSE may have...... a similar positive effect on the quality of the system models and the resulting products and may therefore be desirable. To define a test-driven model-based systems engineering (TD-MBSE) approach, we must define this approach for numerous sub disciplines such as modeling of requirements, use cases......, scenarios, behavior, architecture, etc. In this paper we present a method that utilizes the formalism of timed automatons with formal and statistical model checking techniques to apply TD-MBSE to the modeling of system architecture and behavior. The results obtained from applying it to an industrial case...

  2. Precipitation-runoff modeling system; user's manual

    Science.gov (United States)

    Leavesley, G.H.; Lichty, R.W.; Troutman, B.M.; Saindon, L.G.

    1983-01-01

    The concepts, structure, theoretical development, and data requirements of the precipitation-runoff modeling system (PRMS) are described. The precipitation-runoff modeling system is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and groundwater recharge. Parameter-optimization and sensitivity analysis capabilites are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model system enhancement and hydrologic modeling research and development. (Author 's abstract)

  3. An Empirical Model for Energy Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rosewater, David Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Scott, Paul [TransPower, Poway, CA (United States)

    2016-03-17

    Improved models of energy storage systems are needed to enable the electric grid’s adaptation to increasing penetration of renewables. This paper develops a generic empirical model of energy storage system performance agnostic of type, chemistry, design or scale. Parameters for this model are calculated using test procedures adapted from the US DOE Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage. We then assess the accuracy of this model for predicting the performance of the TransPower GridSaver – a 1 MW rated lithium-ion battery system that underwent laboratory experimentation and analysis. The developed model predicts a range of energy storage system performance based on the uncertainty of estimated model parameters. Finally, this model can be used to better understand the integration and coordination of energy storage on the electric grid.

  4. Investigation of human system interface design in nuclear power plant

    International Nuclear Information System (INIS)

    Feng Yan; Zhang Yunbo; Wang Zhongqiu

    2012-01-01

    The paper introduces the importance of HFE in designing nuclear power plant, and introduces briefly the content and scope of HFE, discusses human system interface design of new built nuclear power plants. This paper also describes human system interface design of foreign nuclear power plant, and describes in detail human system interface design of domestic nuclear power plant. (authors)

  5. Systems biology approaches and pathway tools for investigating cardiovascular disease

    NARCIS (Netherlands)

    Wheelock, C.E.; Wheelock, A.M.; Kawashima, S.; Diez, D.; Kanehisa, M.; Erk, M. van; Kleemann, R.; Haeggström, J.Z.; Goto, S.

    2009-01-01

    Systems biology aims to understand the nonlinear interactions of multiple biomolecular components that characterize a living organism. One important aspect of systems biology approaches is to identify the biological pathways or networks that connect the differing elements of a system, and examine

  6. Molten carbonate fuel cell: dynamic numerical modeling and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Elisangela Martins [National Institute for Space Research, Cachoeira Paulista, SP (Brazil). Combustion and Propulsion Lab.], e-mail: elisangela@lcp.inpe.br; Jabbari, Faryar [University of California, Irvine, CA (United States). Mechanical and Aerospace Engineering Dept.], e-mail: fjabbari@uci.edu; Brouwer, Jacob [University of California, Irvine, CA (United States). National Fuel Cell Research Center], e-mail: jb@nfcrc.uci.edu

    2006-07-01

    In this paper, a detailed model incorporating simplified geometric resolution of a molten carbonate fuel cell (MCFC) with detailed and dynamic simulation of all physical, chemical, and electrochemical processes in the stream-wise direction is presented. The model was developed using mass and momentum conservation, electrochemical and chemical reaction mechanisms, and heat transfer. Results from the model are compared with data from an experimental MCFC unit. Furthermore, the model was applied to predict dynamic variations of voltage, current and temperature in an MCFC as it responds to varying load demands. The voltage was evaluated by applying a model developed by Yu h and Selman (1991a, 1991b). The results show that the model can be used to predict voltage and dynamic response characteristics of an MCFC accurately and consistently for a variety of temperatures and pressures. (author)

  7. Brief History of Agricultural Systems Modeling

    Science.gov (United States)

    Jones, James W.; Antle, John M.; Basso, Bruno O.; Boote, Kenneth J.; Conant, Richard T.; Foster, Ian; Godfray, H. Charles J.; Herrrero, Mario; Howitt, Richard E.; Janssen, Sandor; hide

    2016-01-01

    Agricultural systems science generates knowledge that allows researchers to consider complex problems or take informed agricultural decisions. The rich history of this science exemplifies the diversity of systems and scales over which they operate and have been studied. Modeling, an essential tool in agricultural systems science, has been accomplished by scientists from a wide range of disciplines, who have contributed concepts and tools over more than six decades. As agricultural scientists now consider the next generation models, data, and knowledge products needed to meet the increasingly complex systems problems faced by society, it is important to take stock of this history and its lessons to ensure that we avoid re-invention and strive to consider all dimensions of associated challenges. To this end, we summarize here the history of agricultural systems modeling and identify lessons learned that can help guide the design and development of next generation of agricultural system tools and methods. A number of past events combined with overall technological progress in other fields have strongly contributed to the evolution of agricultural system modeling, including development of process-based bio-physical models of crops and livestock, statistical models based on historical observations, and economic optimization and simulation models at household and regional to global scales. Characteristics of agricultural systems models have varied widely depending on the systems involved, their scales, and the wide range of purposes that motivated their development and use by researchers in different disciplines. Recent trends in broader collaboration across institutions, across disciplines, and between the public and private sectors suggest that the stage is set for the major advances in agricultural systems science that are needed for the next generation of models, databases, knowledge products and decision support systems. The lessons from history should be considered

  8. Numerical Investigation of Turbulence Models for a Superlaminar Journal Bearing

    Directory of Open Access Journals (Sweden)

    Aoshuang Ding

    2018-01-01

    Full Text Available With rotating machineries working at high speeds, oil flow in bearings becomes superlaminar. Under superlaminar conditions, flow exhibits between laminar and fully developed turbulence. In this study, superlaminar oil flow in an oil-lubricated tilting-pad journal bearing is analyzed through computational fluid dynamics (CFD. A three-dimensional bearing model is established. CFD results from the laminar model and 14 turbulence models are compared with experimental findings. The laminar simulation results of pad-side pressure are inconsistent with the experimental data. Thus, the turbulence effects on superlaminar flow should be considered. The simulated temperature and pressure distributions from the classical fully developed turbulence models cannot correctly fit the experimental data. As such, turbulence models should be corrected for superlaminar flow. However, several corrections, such as transition correction, are unsuitable. Among all the flow models, the SST model with low-Re correction exhibits the best pressure distribution and turbulence viscosity ratio. Velocity profile analysis confirms that a buffer layer plays an important role in the superlaminar boundary layer. Classical fully developed turbulence models cannot accurately predict the buffer layer, but this problem can be resolved by initiating an appropriate low-Re correction. Therefore, the SST model with low-Re correction yields suitable results for superlaminar flows in bearings.

  9. The impact of working memory and the "process of process modelling" on model quality: Investigating experienced versus inexperienced modellers

    DEFF Research Database (Denmark)

    Martini, Markus; Pinggera, Jakob; Neurauter, Manuel

    2016-01-01

    A process model (PM) represents the graphical depiction of a business process, for instance, the entire process from online ordering a book until the parcel is delivered to the customer. Knowledge about relevant factors for creating PMs of high quality is lacking. The present study investigated...... of reconciliation phases was positively related to PM quality in experienced modellers. Our research reveals central cognitive mechanisms in process modelling and has potential practical implications for the development of modelling software and teaching the craft of process modelling....

  10. The Community Earth System Model: A Framework for Collaborative Research

    Energy Technology Data Exchange (ETDEWEB)

    Hurrell, Jim; Holland, Marika M.; Gent, Peter R.; Ghan, Steven J.; Kay, Jennifer; Kushner, P.; Lamarque, J.-F.; Large, William G.; Lawrence, David M.; Lindsay, Keith; Lipscomb, William; Long , Matthew; Mahowald, N.; Marsh, D.; Neale, Richard; Rasch, Philip J.; Vavrus, Steven J.; Vertenstein, Mariana; Bader, David C.; Collins, William D.; Hack, James; Kiehl, J. T.; Marshall, Shawn

    2013-09-30

    The Community Earth System Model (CESM) is a flexible and extensible community tool used to investigate a diverse set of earth system interactions across multiple time and space scales. This global coupled model is a natural evolution from its predecessor, the Community Climate System Model, following the incorporation of new earth system capabilities. These include the ability to simulate biogeochemical cycles, atmospheric chemistry, ice sheets, and a high-top atmosphere. These and other new model capabilities are enabling investigations into a wide range of pressing scientific questions, providing new predictive capabilities and increasing our collective knowledge about the behavior and interactions of the earth system. Simulations with numerous configurations of the CESM have been provided to the Coupled Model Intercomparison Project Phase 5 (CMIP5) and are being analyzed by the broader community of scientists. Additionally, the model source code and associated documentation are freely available to the scientific community to use for earth system studies, making it a true community tool. Here we describe this earth modeling system, its various possible configurations, and illustrate its capabilities with a few science highlights.

  11. Human errors and system variability in safety investigations of ...

    African Journals Online (AJOL)

    The International Maritime Organization has achieved a milestone by the adoption of the new Casualty Investigation Code, which is now mandatory as prescribed in regulation XI-116 of the Safety of Life at Sea Convention, 1974, as amended. Until OJ January 2010, the IMO Code for casualty investigation was annexed to ...

  12. Validation of a robotic balance system for investigations in the control of human standing balance.

    Science.gov (United States)

    Luu, Billy L; Huryn, Thomas P; Van der Loos, H F Machiel; Croft, Elizabeth A; Blouin, Jean-Sébastien

    2011-08-01

    Previous studies have shown that human body sway during standing approximates the mechanics of an inverted pendulum pivoted at the ankle joints. In this study, a robotic balance system incorporating a Stewart platform base was developed to provide a new technique to investigate the neural mechanisms involved in standing balance. The robotic system, programmed with the mechanics of an inverted pendulum, controlled the motion of the body in response to a change in applied ankle torque. The ability of the robotic system to replicate the load properties of standing was validated by comparing the load stiffness generated when subjects balanced their own body to the robot's mechanical load programmed with a low (concentrated-mass model) or high (distributed-mass model) inertia. The results show that static load stiffness was not significantly (p > 0.05) different for standing and the robotic system. Dynamic load stiffness for the robotic system increased with the frequency of sway, as predicted by the mechanics of an inverted pendulum, with the higher inertia being accurately matched to the load properties of the human body. This robotic balance system accurately replicated the physical model of standing and represents a useful tool to simulate the dynamics of a standing person. © 2011 IEEE

  13. Formal Modeling and Analysis of Timed Systems

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Niebert, Peter

    This book constitutes the thoroughly refereed post-proceedings of the First International Workshop on Formal Modeling and Analysis of Timed Systems, FORMATS 2003, held in Marseille, France in September 2003. The 19 revised full papers presented together with an invited paper and the abstracts...... of two invited talks were carefully selected from 36 submissions during two rounds of reviewing and improvement. All current aspects of formal method for modeling and analyzing timed systems are addressed; among the timed systems dealt with are timed automata, timed Petri nets, max-plus algebras, real......-time systems, discrete time systems, timed languages, and real-time operating systems....

  14. Grey Box Modelling of Hydrological Systems

    DEFF Research Database (Denmark)

    Thordarson, Fannar Ørn

    The main topic of the thesis is grey box modelling of hydrologic systems, as well as formulation and assessment of their embedded uncertainties. Grey box model is a combination of a white box model, a physically-based model that is traditionally formulated using deterministic ordinary differential...... the lack of fit in state space formulation, and further support decisions for a model expansion. By using stochastic differential equations to formulate the dynamics of the hydrological system, either the complexity of the model can be increased by including the necessary hydrological processes...... in the model, or formulation of process noise can be considered so that it meets the physical limits of the hydrological system and give an adequate description of the embedded uncertainty in model structure. The thesis consists of two parts: a summary report and a part which contains six scientific papers...

  15. Modelling of Joint Crowd-Structure System Using Equivalent Reduced-DOF System

    Directory of Open Access Journals (Sweden)

    Jackie Sim

    2007-01-01

    Full Text Available For human assembly structures in which the mass of the crowd is significant compared to that of the structure, it is necessary to model the passive crowd as a dynamic system added to the main structural system. Earlier work by the authors has analysed the frequency response of a joint crowd-structure system in which the structure is treated as a single degree-of-freedom (SDOF system and the seated and standing crowds are each modelled as a two degree-of-freedom (2DOF system. It was found that the occupied structure has dynamic properties different to the empty structure. This paper investigates representing the joint crowd-structure system as an equivalent reduced-DOF system that would have the advantage of simplifying the analysis. The modal properties of the equivalent reduced-DOF system, if known, can give a useful indication of how the passive crowd affects the modal properties of the occupied structure. Two equivalent reduced-DOF systems are investigated – SDOF and 3DOF systems. The errors between the responses of the equivalent systems and the full model are calculated and presented in the paper. The results show that the full model exhibits the behaviour of a SDOF system for structures with natural frequencies less than 4 Hz (when empty, whereas for structures with natural frequencies above 4 Hz the equivalent 3DOF system gives a better fit to the full model.

  16. The Guided System Development Framework: Modeling and Verifying Communication Systems

    DEFF Research Database (Denmark)

    Carvalho Quaresma, Jose Nuno; Probst, Christian W.; Nielson, Flemming

    2014-01-01

    . The Guided System Development framework contributes to more secure communication systems by aiding the development of such systems. The framework features a simple modelling language, step-wise refinement from models to implementation, interfaces to security verification tools, and code generation from...... the verified specification. The refinement process carries thus security properties from the model to the implementation. Our approach also supports verification of systems previously developed and deployed. Internally, the reasoning in our framework is based on the Beliefs and Knowledge tool, a verification...

  17. System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Whitmore, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kaffine, Leah [National Renewable Energy Lab. (NREL), Golden, CO (United States); Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron P. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

  18. Thutmose - Investigation of Machine Learning-Based Intrusion Detection Systems

    Science.gov (United States)

    2016-06-01

    3.2.8 ICS and SCADA ...classification model re-trained? Is the existing model updated or is it replaced with a new one? • How often is the model re-trained and how much new...run as each one processed more quickly, leading to less variance in results. 3.2.8 ICS and SCADA . Having been granted access to Industrial Control

  19. Investigation of Burnup Credit Modeling Issues Associated with BWR Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.C.

    2000-10-12

    /or decreasing the neutron absorber concentration. However, regulations associated with permanent disposal require consideration of scenarios and/or package conditions that are not relevant or credible for storage or transportation, and as a result, necessitate credit for burnup in BWR fuel to maintain capacity objectives. Burnup credit relies on depletion calculations to provide a conservative estimate of spent fuel contents and subsequent criticality calculations to assess the value of k{sub eff} for a spent fuel cask or a fuel configuration under a variety of postulated conditions. Therefore, validation is necessary to quantify biases and uncertainties between analytic predictions and measured isotopics. However, the design and operational aspects of BWRs result in a more heterogeneous and time-varying reactor configuration than those of PWRs. Thus, BWR spent fuel analyses and validation efforts are significantly more complicated than those of their PWR counterparts. BWR spent fuel assemblies are manufactured with variable enrichments, both radially and axially, are exposed to time- and spatially-varying void distributions, contain integral burnable absorber rods, and are subject to partial control-blade insertion during operation. The latter is especially true in older fuel assemblies. Away-from-reactor depletion tools used for characterization of spent fuel have typically been developed and validated for more homogeneous PWR fuel assemblies without integral burnable absorber rods, and thus must be reassessed for BWR configurations to determine a conservative methodology for estimating the isotopic content of spent BWR fuel. This report examines the use of SAS2H8 for calculating spent BWR fuel isotopics for burnup-credit criticality safety analyses and assesses the adequacy of SAS2H for this task. The effects of SAS2H modeling assumptions on calculated spent BWR fuel isotopics and the effects of depletion assumptions on calculated k{sub inf} values are investigated. Detailed

  20. Coupling population dynamics with earth system models: the POPEM model.

    Science.gov (United States)

    Navarro, Andrés; Moreno, Raúl; Jiménez-Alcázar, Alfonso; Tapiador, Francisco J

    2017-09-16

    Precise modeling of CO 2 emissions is important for environmental research. This paper presents a new model of human population dynamics that can be embedded into ESMs (Earth System Models) to improve climate modeling. Through a system dynamics approach, we develop a cohort-component model that successfully simulates historical population dynamics with fine spatial resolution (about 1°×1°). The population projections are used to improve the estimates of CO 2 emissions, thus transcending the bulk approach of existing models and allowing more realistic non-linear effects to feature in the simulations. The module, dubbed POPEM (from Population Parameterization for Earth Models), is compared with current emission inventories and validated against UN aggregated data. Finally, it is shown that the module can be used to advance toward fully coupling the social and natural components of the Earth system, an emerging research path for environmental science and pollution research.

  1. Investigations for modelling hardness of biomedical implant during ...

    Indian Academy of Sciences (India)

    Rupinder Singh

    Abstract. In the present work, effort has been made for modelling the microhardness of biomedical implant prepared by combining fused deposition modelling, vacuum moulding and stir casting (SC) process. A dynamic condylar screw (DCS) plate was selected as a real '3D' biomedical implant for this case study. The DCS ...

  2. Investigating Secondary School Students’ Difficulties in Modeling Problems PISA-Model Level 5 And 6

    Directory of Open Access Journals (Sweden)

    Sri Imelda Edo

    2013-01-01

    Full Text Available The chart of Indonesian student of mathematical ability development in Program for International Student Assessment (PISA event during the last 4 periods shows an unstable movement. PISA aims to examine the ability of children aged 15 years in  reading literacy,  mathematics literacy, and science literacy. The concept of mathematical literacy is closely related to several other concepts discussed in mathematics education. The most important is mathematical modelling and its component processes.  Therefore the goal of this research is to investigate  secondary school students’ difficulties in modeling problems PISA-model level 5 and 6. Qualitative  research was used as an appropriate mean to achieve this research goal. This type of research is a greater emphasizing on holistic description, and phenomenon identified to be studied,  students’  difficulties  in modelling real world problem in PISA model question level 5 and 6. 26 grade 9 students of SMPN 1Palembang, 26 grade 9  students of SMPK Frater Xaverius 1 Palembang, and 31 participants of mathematical literacy context event, were involved in this research. The result of investigate showed  that student is difficult  to; (1  formulating  situations mathematically, Such as to representing a situation mathematically, recognizing mathematical structure (including  regularities, relationships, and patterns in problems, (2 evaluating the reasonableness of a mathematical solution in the context of a real-world problem. The students have no problem in solve mathematical problem they have constructed.Keywords: Mathematical model, Modelling competence, PISA, PISA Questions level 5 and 6, Students’difficulties in solving PISA-model Questions. Mathematics Literacy. DOI: http://dx.doi.org/10.22342/jme.4.1.561.41-58

  3. Spinal Cord Injury Model System Information Network

    Science.gov (United States)

    ... the UAB-SCIMS Contact the UAB-SCIMS UAB Spinal Cord Injury Model System Newly Injured Health Daily Living Consumer ... Information Network The University of Alabama at Birmingham Spinal Cord Injury Model System (UAB-SCIMS) maintains this Information Network ...

  4. Statistical Model Checking for Stochastic Hybrid Systems

    DEFF Research Database (Denmark)

    David, Alexandre; Du, Dehui; Larsen, Kim Guldstrand

    2012-01-01

    This paper presents novel extensions and applications of the UPPAAL-SMC model checker. The extensions allow for statistical model checking of stochastic hybrid systems. We show how our race-based stochastic semantics extends to networks of hybrid systems, and indicate the integration technique ap...

  5. Systemic, Ecological Model for Rehabilitation Counseling.

    Science.gov (United States)

    Hershenson, David B.

    1998-01-01

    Presents a reformulation of Hershenson's theoretical model for rehabilitation counseling in systemic and ecological terms. This macrosystem is organized by precipitating event of disability and is composed of four systems: consumer, functional, provider, and contextual. Discusses the use of the model for selecting rehabilitation interventions…

  6. Modeling complex work systems - method meets reality

    NARCIS (Netherlands)

    van der Veer, Gerrit C.; Hoeve, Machteld; Lenting, Bert

    1996-01-01

    Modeling an existing task situation is often a first phase in the (re)design of information systems. For complex systems design, this model should consider both the people and the organization involved, the work, and situational aspects. Groupware Task Analysis (GTA) as part of a method for the

  7. Dynamic modeling of the INAPRO aquaponic system

    NARCIS (Netherlands)

    Karimanzira, Divas; Keesman, Karel J.; Kloas, Werner; Baganz, Daniela; Rauschenbach, Thomas

    2016-01-01

    The use of modeling techniques to analyze aquaponics systems is demonstrated with an example of dynamic modeling for the production of Nile tilapia (Oreochromis niloticus) and tomatoes (Solanum lycopersicon) using the innovative double recirculating aquaponic system ASTAF-PRO. For the management

  8. Detailed modelling and optimal design of membrane separation systems

    OpenAIRE

    Marriott, J. I.

    2001-01-01

    The search for alternatives to traditional energy intensive separation methods such as distillation has led to the introduction of processes based on membranes. In this research, the use of detailed mathematical models for the optimal design of membrane systems is investigated. Mathematical models of hollow-fibre and spiral-wound membrane modules are presented in this thesis. The models are developed from rigorous mass, momentum and energy balances and can be used to describ...

  9. Formal heterogeneous system modeling with SystemC

    DEFF Research Database (Denmark)

    Niaki, Seyed Hosein Attarzadeh; Jakobsen, Mikkel Koefoed; Sulonen, Tero

    2012-01-01

    Electronic System Level (ESL) design of embedded systems proposes raising the abstraction level of the design entry to cope with the increasing complexity of such systems. To exploit the benefits of ESL, design languages should allow specification of models which are a) heterogeneous, to describe...... to focus on specifying the pure functional aspects. A key advantage is that the formalism is used to export the structure and behavior of the models via introspection as an abstract representation for further analysis and synthesis....

  10. Regression Models for Repairable Systems

    Czech Academy of Sciences Publication Activity Database

    Novák, Petr

    2015-01-01

    Roč. 17, č. 4 (2015), s. 963-972 ISSN 1387-5841 Institutional support: RVO:67985556 Keywords : Reliability analysis * Repair models * Regression Subject RIV: BB - Applied Statistics , Operational Research Impact factor: 0.782, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/novak-0450902.pdf

  11. Investigation of physical imaging properties in various digital radiography systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hoi Woun [Dept. of Radiological Science, Baekseok Culture University, Cheonan (Korea, Republic of); Min, Jung Hwan [Dept. of Radiological technology, Shingu University, Seongnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Kyushu (Japan); Kim, Jung Min [Dept. of Health and Environmental Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

    2017-09-15

    We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

  12. Communication System Architectures for Missions to Mars - A Preliminary Investigation

    Science.gov (United States)

    Nguyen, T.; Hinedi, S.; Martin, W.; Tsou, H.

    1995-01-01

    This paper presents various communication system architectures for Multiple-Link communications with Single Aperture (MULSA) ground station. The proposed architectures are capable of supporting a multiplicity of spacecraft that are within the beamwidth of a single ground station antenna simultaneously. Both short and long term proposals to address this scenario will be discussed. In addition, the paper also discusses the top-level system designs of the proposed architectures and attempts to identify the associated advantages and disadvantages for each system.

  13. Investigation of SPM in WDM System with EDFA

    Directory of Open Access Journals (Sweden)

    Tomáš Ivaniga

    2016-12-01

    Full Text Available The article describes a nonlinear phenomenon SPM (Self Phase Modulation, which occurs in the all-optical communications systems. In the 21st century, the WDM (Wavelength Division Multiplex system cannot be created without the software that simulates the system under real conditions. The most important WDM components include the EDFA (Erbium Doped Fiber Amplifier, in which amplification occurs at all wavelengths. The 10 Gbps optical line DWDM (Dense Wavelength Division Multiplex system is created according to the ITU-T.G.694.1, in which the SPM phenomenon is observed.

  14. Mathematical Modeling Of Life-Support Systems

    Science.gov (United States)

    Seshan, Panchalam K.; Ganapathi, Balasubramanian; Jan, Darrell L.; Ferrall, Joseph F.; Rohatgi, Naresh K.

    1994-01-01

    Generic hierarchical model of life-support system developed to facilitate comparisons of options in design of system. Model represents combinations of interdependent subsystems supporting microbes, plants, fish, and land animals (including humans). Generic model enables rapid configuration of variety of specific life support component models for tradeoff studies culminating in single system design. Enables rapid evaluation of effects of substituting alternate technologies and even entire groups of technologies and subsystems. Used to synthesize and analyze life-support systems ranging from relatively simple, nonregenerative units like aquariums to complex closed-loop systems aboard submarines or spacecraft. Model, called Generic Modular Flow Schematic (GMFS), coded in such chemical-process-simulation languages as Aspen Plus and expressed as three-dimensional spreadsheet.

  15. Systematic modelling and simulation of refrigeration systems

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.; Jakobsen, Arne

    1998-01-01

    The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose of the s......The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose...... of the simulation, to select appropriate component models and to set up the equations in a well-arranged way. In this paper the outline of such a method is proposed and examples showing the use of this method for simulation of refrigeration systems are given....

  16. Modeling and analysis of stochastic systems

    CERN Document Server

    Kulkarni, Vidyadhar G

    2011-01-01

    Based on the author's more than 25 years of teaching experience, Modeling and Analysis of Stochastic Systems, Second Edition covers the most important classes of stochastic processes used in the modeling of diverse systems, from supply chains and inventory systems to genetics and biological systems. For each class of stochastic process, the text includes its definition, characterization, applications, transient and limiting behavior, first passage times, and cost/reward models. Along with reorganizing the material, this edition revises and adds new exercises and examples. New to the second edi

  17. Multi-scenario modelling of uncertainty in stochastic chemical systems

    International Nuclear Information System (INIS)

    Evans, R. David; Ricardez-Sandoval, Luis A.

    2014-01-01

    Uncertainty analysis has not been well studied at the molecular scale, despite extensive knowledge of uncertainty in macroscale systems. The ability to predict the effect of uncertainty allows for robust control of small scale systems such as nanoreactors, surface reactions, and gene toggle switches. However, it is difficult to model uncertainty in such chemical systems as they are stochastic in nature, and require a large computational cost. To address this issue, a new model of uncertainty propagation in stochastic chemical systems, based on the Chemical Master Equation, is proposed in the present study. The uncertain solution is approximated by a composite state comprised of the averaged effect of samples from the uncertain parameter distributions. This model is then used to study the effect of uncertainty on an isomerization system and a two gene regulation network called a repressilator. The results of this model show that uncertainty in stochastic systems is dependent on both the uncertain distribution, and the system under investigation. -- Highlights: •A method to model uncertainty on stochastic systems was developed. •The method is based on the Chemical Master Equation. •Uncertainty in an isomerization reaction and a gene regulation network was modelled. •Effects were significant and dependent on the uncertain input and reaction system. •The model was computationally more efficient than Kinetic Monte Carlo

  18. Investigation of Transformer Model for TRV Calculation by EMTP

    Science.gov (United States)

    Thein, Myo Min; Ikeda, Hisatoshi; Harada, Katsuhiko; Ohtsuka, Shinya; Hikita, Masayuki; Haginomori, Eiichi; Koshiduka, Tadashi

    Analysis of the EMTP transformer model was performed with the 4kVA two windings low voltage transformer with the current injection (CIJ) measurement method to study a transient recovery voltage (TRV) at the transformer limited fault (TLF) current interrupting condition. Tested transformer's impedance was measured by the frequency response analyzer (FRA). From FRA measurement graphs leakage inductance, stray capacitance and resistance were calculated. The EMTP transformer model was constructed with those values. The EMTP simulation was done for a current injection circuit by using transformer model. The experiment and simulation results show a reasonable agreement.

  19. Formal heterogeneous system modeling with SystemC

    DEFF Research Database (Denmark)

    Niaki, Seyed Hosein Attarzadeh; Jakobsen, Mikkel Koefoed; Sulonen, Tero

    2012-01-01

    Electronic System Level (ESL) design of embedded systems proposes raising the abstraction level of the design entry to cope with the increasing complexity of such systems. To exploit the benefits of ESL, design languages should allow specification of models which are a) heterogeneous, to describe...

  20. Milan systemic family therapy: a review of 10 empirical investigations

    OpenAIRE

    Carr, Alan

    1991-01-01

    Ten empirical investigations of Milan Family Therapy (MFT) are reviewed in this paper. The studies include both single and comparative group outcome trials; investigations of therapeutic process; clinical audit and consumer satisfaction surveys. Substantive findings and methodological issues are discussed in the light of family therapy and individual psychotherapy research generally. Findings indicate that MFT may lead to symptomatic change in two-thirds to three-quarters of cases and to syst...

  1. Systems Engineering Model for ART Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

  2. Modeling aluminum-air battery systems

    Science.gov (United States)

    Savinell, R. F.; Willis, M. S.

    The performance of a complete aluminum-air battery system was studied with a flowsheet model built from unit models of each battery system component. A plug flow model for heat transfer was used to estimate the amount of heat transferred from the electrolyte to the air stream. The effect of shunt currents on battery performance was found to be insignificant. Using the flowsheet simulator to analyze a 100 cell battery system now under development demonstrated that load current, aluminate concentration, and electrolyte temperature are dominant variables controlling system performance. System efficiency was found to decrease as both load current and aluminate concentration increases. The flowsheet model illustrates the interdependence of separate units on overall system performance.

  3. Investigation of mechanistic deterioration modeling for bridge design and management.

    Science.gov (United States)

    2017-04-01

    The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical pro...

  4. Preclinical models to investigate retinal ischemia: Advances and drawbacks

    Directory of Open Access Journals (Sweden)

    Gillipsie eMinhas

    2012-05-01

    Full Text Available Retinal ischemia is a frequent source of irreparable visual impairment affecting over a hundred million individuals in the world. It is associated with a wide range of retinal disorders like ischemic optic neuropathies, obstructive retinopathies, carotid occlusive disorders, diabetic retinopathy and glaucoma. Compared to other tissues retina has a higher metabolic rate; any disruption in blood supply can have an effect on the supply of oxygen leading to retinal ischemia. If occlusion is not rescued the outcome is irreversible with ischemic and apoptotic cascades resulting in cell death. In addition to in-vitro models, animal models are necessary to further our understanding of the etiology, pathology, and evolution of retinal ischemia besides the evaluation, development, and improvement of therapeutic strategies. The various existing animal models of retinal ischemia are characterised by obstruction of retinal circulation that allows the study of neurovascular changes. In this review we provide an overview of major models and emerging preclinical therapeutic strategies.

  5. Investigation of SSR Characteristics of Hybrid Series Compensated Power System with SSSC

    Directory of Open Access Journals (Sweden)

    R. Thirumalaivasan

    2011-01-01

    Full Text Available The advent of series FACTS controllers, thyristor controlled series capacitor (TCSC and static synchronous Series Compensator (SSSC has made it possible not only for the fast control of power flow in a transmission line, but also for the mitigation of subsynchronous resonance (SSR in the presence of fixed series capacitors. SSSC is an emerging controller and this paper presents SSR characteristics of a series compensated system with SSSC. The study system is adapted from IEEE first benchmark model (FBM. The active series compensation is provided by a three-level twenty four-pulse SSSC. The modeling and control details of a three level voltage source converter-(VSC-based SSSC are discussed. The SSR characteristics of the combined system with constant reactive voltage control mode in SSSC has been investigated. It is shown that the constant reactive voltage control of SSSC has the effect of reducing the electrical resonance frequency, which detunes the SSR. The analysis of SSR with SSSC is carried out based on frequency domain method, eigenvalue analysis and transient simulation. While the eigenvalue and damping torque analysis are based on linearizing the D-Q model of SSSC, the transient simulation considers both D-Q and detailed three phase nonlinear system model using switching functions.

  6. Investigating Educational Systems, Leadership, and School Culture: A Holistic Approach

    Science.gov (United States)

    Pratt, Jill Elizabeth

    2014-01-01

    Most populous school districts operate using a bureaucratic hierarchical organizational structure developed primarily for industry, a system structure that has remained intact for a century despite evolving from a manufacturing to a knowledge-based economy. Although strong for efficiency, this system structure is resistant to change and promotes…

  7. Model-Based Design for Embedded Systems

    CERN Document Server

    Nicolescu, Gabriela

    2009-01-01

    Model-based design allows teams to start the design process from a high-level model that is gradually refined through abstraction levels to ultimately yield a prototype. This book describes the main facets of heterogeneous system design. It focuses on multi-core methodological issues, real-time analysis, and modeling and validation

  8. Further investigations on the role of ascorbic acid in stratum corneum lipid models after UV exposure.

    Science.gov (United States)

    Trommer, Hagen; Böttcher, Rolf; Huschka, Christoph; Wohlrab, Wolfgang; Neubert, Reinhard H H

    2005-08-01

    This study is the continuation of our research into vitamin C and its possible effects on human skin after topical administration. The effects of ascorbic acid, iron ions and UV irradiation on stratum corneum lipid models were investigated. The lipid models used were: a simple system (linolenic acid dispersion), a complex system (liposomes consisting of dipalmitoylphosphatidylcholine, cholesterol and linolenic acid) and complex systems with additionally incorporated ceramides (types III and IV). The lipid peroxidation was quantified by the thiobarbituric acid assay. A human adult low-calcium high-temperature (HaCaT) keratinocytes cell culture was used as a second in-vitro model. The amount of intracellular peroxides was determined by measuring the fluorescence intensity using the dihydrorhodamine 123 assay. Electron paramagnetic resonance spectroscopy was used to study the influence of ascorbic acid and iron ions on the signal intensity of 5-doxylstearic acid during UV exposure. Ascorbic acid showed prooxidative properties in the thiobarbituric acid assay whereas cell protection was measured in the HaCaT keratinocytes experiments. Electron paramagnetic resonance investigations revealed different extents of free radical production generated by iron ions, ascorbic acid and UV irradiation. In evaluating the results from this study new aspects of the mechanism of lipid damage caused by these three factors were suggested, transcending the simple redox behaviour of ascorbic acid.

  9. Site investigation SFR. Hydrogeological modelling of SFR. Model version 0.2

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Johan (Golder Associates AB (Sweden)); Follin, Sven (SF GeoLogic (Sweden))

    2010-01-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has conducted site investigations for a planned extension of the existing final repository for short-lived radioactive waste (SFR). A hydrogeological model is developed in three model versions, which will be used for safety assessment and design analyses. This report presents a data analysis of the currently available hydrogeological data from the ongoing Site Investigation SFR (KFR27, KFR101, KFR102A, KFR102B, KFR103, KFR104, and KFR105). The purpose of this work is to develop a preliminary hydrogeological Discrete Fracture Network model (hydro-DFN) parameterisation that can be applied in regional-scale modelling. During this work, the Geologic model had not yet been updated for the new data set. Therefore, all analyses were made to the rock mass outside Possible Deformation Zones, according to Single Hole Interpretation. Owing to this circumstance, it was decided not to perform a complete hydro-DFN calibration at this stage. Instead focus was re-directed to preparatory test cases and conceptual questions with the aim to provide a sound strategy for developing the hydrogeological model SFR v. 1.0. The presented preliminary hydro-DFN consists of five fracture sets and three depth domains. A statistical/geometrical approach (connectivity analysis /Follin et al. 2005/) was performed to estimate the size (i.e. fracture radius) distribution of fractures that are interpreted as Open in geologic mapping of core data. Transmissivity relations were established based on an assumption of a correlation between the size and evaluated specific capacity of geologic features coupled to inflows measured by the Posiva Flow Log device (PFL-f data). The preliminary hydro-DFN was applied in flow simulations in order to test its performance and to explore the role of PFL-f data. Several insights were gained and a few model technical issues were raised. These are summarised in Table 5-1

  10. Site investigation SFR. Hydrogeological modelling of SFR. Model version 0.2

    International Nuclear Information System (INIS)

    Oehman, Johan; Follin, Sven

    2010-01-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has conducted site investigations for a planned extension of the existing final repository for short-lived radioactive waste (SFR). A hydrogeological model is developed in three model versions, which will be used for safety assessment and design analyses. This report presents a data analysis of the currently available hydrogeological data from the ongoing Site Investigation SFR (KFR27, KFR101, KFR102A, KFR102B, KFR103, KFR104, and KFR105). The purpose of this work is to develop a preliminary hydrogeological Discrete Fracture Network model (hydro-DFN) parameterisation that can be applied in regional-scale modelling. During this work, the Geologic model had not yet been updated for the new data set. Therefore, all analyses were made to the rock mass outside Possible Deformation Zones, according to Single Hole Interpretation. Owing to this circumstance, it was decided not to perform a complete hydro-DFN calibration at this stage. Instead focus was re-directed to preparatory test cases and conceptual questions with the aim to provide a sound strategy for developing the hydrogeological model SFR v. 1.0. The presented preliminary hydro-DFN consists of five fracture sets and three depth domains. A statistical/geometrical approach (connectivity analysis /Follin et al. 2005/) was performed to estimate the size (i.e. fracture radius) distribution of fractures that are interpreted as Open in geologic mapping of core data. Transmissivity relations were established based on an assumption of a correlation between the size and evaluated specific capacity of geologic features coupled to inflows measured by the Posiva Flow Log device (PFL-f data). The preliminary hydro-DFN was applied in flow simulations in order to test its performance and to explore the role of PFL-f data. Several insights were gained and a few model technical issues were raised. These are summarised in Table 5-1

  11. Investigating the Impact of Wind Turbines on Distribution System Stability

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Rishabh; Zhang, Yingchen; Hodge, Bri-Mathias

    2016-12-12

    Modern wind turbines utilize power electronic converters to regulate their output and optimize their performance. Their impact on the distribution system is not as well understood as for transmission system. The novelty of this work is in studying the impact of wind turbines given its proximity to faults or severe voltage events, and the influence on system stability given its location relative to the substation (representing the conventional grid). This paper presents the frequency and voltage swing plots for various study scenarios. The responses are analyzed two fold - Steady state operation, and performance given a fault or voltage events occurs in the system. The findings are presented, with crucial differences from transmission systems highlighted.

  12. An investigation of the ternary system Nb-Ti-Al

    International Nuclear Information System (INIS)

    Kaltenbach, K.; Gama, S.

    1984-01-01

    The binary systems Nb-Ti, Nb-Al and Al-Ti as well the ternary system Nb-Ti-Al were studied by the aid of arc-beam melted alloys. The as-cast alloys and samples heat treated at 1200 0 C were examined and the liquidus surface projection, an isothermal section at 1200 0 C and the reaction scheme of the system Nb-Ti-Al were constructed. The phase relations of the binary systems Nb-Ti and Nb-Al were confirmed, in the system Al-Ti still some examinations are necessary to resolve the existing uncertainties. The melting process of Nb-Ti alloys in the electron-beam furnace has been studied. (Author) [pt

  13. Critically Important Object Security System Element Model

    Directory of Open Access Journals (Sweden)

    I. V. Khomyackov

    2012-03-01

    Full Text Available A stochastic model of critically important object security system element has been developed. The model includes mathematical description of the security system element properties and external influences. The state evolution of the security system element is described by the semi-Markov process with finite states number, the semi-Markov matrix and the initial semi-Markov process states probabilities distribution. External influences are set with the intensity of the Poisson thread.

  14. A model for international border management systems.

    Energy Technology Data Exchange (ETDEWEB)

    Duggan, Ruth Ann

    2008-09-01

    To effectively manage the security or control of its borders, a country must understand its border management activities as a system. Using its systems engineering and security foundations as a Department of Energy National Security Laboratory, Sandia National Laboratories has developed such an approach to modeling and analyzing border management systems. This paper describes the basic model and its elements developed under Laboratory Directed Research and Development project 08-684.

  15. Reforming the road freight transportation system using systems thinking: An investigation of Coronial inquests in Australia.

    Science.gov (United States)

    Newnam, Sharon; Goode, Natassia; Salmon, Paul; Stevenson, Mark

    2017-04-01

    Road freight transport is considered to be one of the most dangerous industries in Australia, accounting for over 30% of all work fatalities. Whilst system reform (i.e., change to policy and practice) is needed, it is not clear what this reform should be, or what approaches should be used to drive it. This article argues that road freight transportation reform should be underpinned by a systems thinking approach. Efforts to understand crash causation should be focused beyond the driver and identify contributing factors at other levels with the road freight system. Accordingly, we present the findings from a study that examined whether Australian Coronial investigations into road freight crashes reflect support appropriate system reform. Content analysis was used to identify the contributing factors and interrelations implicated in the road freight crashes described in publicly available Australian Coroner's inquest reports from the last 10 years (2004-2014; n=21). The results found evidence to suggest that the Coronial inquests provide some understanding of the complex system of factors influencing road freight transportation crashes in Australia. However, there was a lack of evidence to suggest an understanding of system-based reform based on the identification of reductionist-focused recommendations. It is concluded that researchers and practitioners (ie., government and industry) need to work together to develop prevention efforts focused on system reforms. Systems thinking based data collection and analysis frameworks are urgently required to help develop this understanding in road freight transportation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Investigation of tracking systems properties in CAVE-type virtual reality systems

    Science.gov (United States)

    Szymaniak, Magda; Mazikowski, Adam; Meironke, Michał

    2017-08-01

    In recent years, many scientific and industrial centers in the world developed a virtual reality systems or laboratories. One of the most advanced solutions are Immersive 3D Visualization Lab (I3DVL), a CAVE-type (Cave Automatic Virtual Environment) laboratory. It contains two CAVE-type installations: six-screen installation arranged in a form of a cube, and four-screen installation, a simplified version of the previous one. The user feeling of "immersion" and interaction with virtual world depend on many factors, in particular on the accuracy of the tracking system of the user. In this paper properties of the tracking systems applied in I3DVL was investigated. For analysis two parameters were selected: the accuracy of the tracking system and the range of detection of markers by the tracking system in space of the CAVE. Measurements of system accuracy were performed for six-screen installation, equipped with four tracking cameras for three axes: X, Y, Z. Rotation around the Y axis was also analyzed. Measured tracking system shows good linear and rotating accuracy. The biggest issue was the range of the monitoring of markers inside the CAVE. It turned out, that the tracking system lose sight of the markers in the corners of the installation. For comparison, for a simplified version of CAVE (four-screen installation), equipped with eight tracking cameras, this problem was not occur. Obtained results will allow for improvement of cave quality.

  17. High-repetition-rate PIV investigations on a generic rocket model in sub- and supersonic flows

    Science.gov (United States)

    Bitter, Martin; Scharnowski, Sven; Hain, Rainer; Kähler, Christian J.

    2011-04-01

    High-repetition-rate PIV measurements were performed in the trisonic wind tunnel facility at the Bundeswehr University Munich in order to investigate the boundary layer parameters on a generic rocket model and the recirculation area in the wake of the model at Mach numbers up to Mach = 2.6. The data are required for the validation of unsteady flow simulations. Because of the limited run time of the blow-down wind tunnel, a high-repetition-rate PIV system was applied to obtain the flow statistics with high accuracy. The results demonstrate this method's potential to resolve small-scale flow phenomena over a wide field of view in a large Mach number range but also show its limitations for the investigations of wall-bounded flows.

  18. Transformer core modeling for magnetizing inrush current investigation

    OpenAIRE

    A.Yahiou; A. Bayadi

    2014-01-01

    The inrush currents generated during an energization of power transformer can reach very high values and may cause many problems in power system. This magnetizing inrush current which occurs at the time of energization of a transformer is due to temporary overfluxing in the transformer core. Its magnitude mainly depends on switching parameters such as the resistance of the primary winding and the point-on-voltage wave (switching angle). This paper describes a system for measuring the inrush c...

  19. Reliability models for Space Station power system

    Science.gov (United States)

    Singh, C.; Patton, A. D.; Kim, Y.; Wagner, H.

    1987-01-01

    This paper presents a methodology for the reliability evaluation of Space Station power system. The two options considered are the photovoltaic system and the solar dynamic system. Reliability models for both of these options are described along with the methodology for calculating the reliability indices.

  20. System identification application using Hammerstein model

    Indian Academy of Sciences (India)

    Saban Ozer

    because of its advanced theoretical background [3–5, 10]. However, many systems in real life have nonlinear beha- ... To describe a polynomial non-linear system with memory, the Volterra series expansion has been the ... suppression and adaptive noise suppression [19]. 2.3 Hammerstein model. Many systems can be ...