Science.gov

Sample records for 5th coupled model

  1. Historical and future land carbon cycle, results from the 5th Coupled Model Intercomparison Project (CMIP5)

    NASA Astrophysics Data System (ADS)

    Friedlingstein, Pierre; Anav, Alessandro; Murray-Tortarolo, Guillermo; Wenzel, Sabrina; Cox, Peter; Eyring, Veronika

    2014-05-01

    The 5th Coupled Model Intercomparison Project (CMIP5) provided a unique source of Earth System Models simulations, generating an unprecedented range of analysis of many components of the climate system. In this presentation we will focus on the land carbon cycle, its response to the historical perturbation and its projected response in the future under the forcing of the different Representative Concentration Pathways (RCPs) scenarios. There is a broad agreement across models on the evolution of the carbon exchange between the atmosphere and the land since the beginning of the industrial revolution. Carbon sink driven by atmospheric CO2 increase more than compensates now the carbon sources due to land use changes, consistent with independent estimates. The future of the land carbon cycle is significantly more uncertain, even for a given RCP scenario. There is no overall agreement across models on the sign of the land carbon sink by the end of the 21st century, land carbon cycle sensitivity to atmospheric CO2 increase and climate change being strongly model dependent. Model evaluation and use of emerging constraint should help reduce uncertainties in future carbon cycle projections.

  2. The 5th Generation model of Particle Physics

    NASA Astrophysics Data System (ADS)

    Lach, Theodore

    2009-05-01

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

  3. Development of a Three-Dimensional Finite Element Chest Model for the 5(th) Percentile Female.

    PubMed

    Kimpara, Hideyuki; Lee, Jong B; Yang, King H; King, Albert I; Iwamoto, Masami; Watanabe, Isao; Miki, Kazuo

    2005-11-01

    Several three-dimensional (3D) finite element (FE) models of the human body have been developed to elucidate injury mechanisms due to automotive crashes. However, these models are mainly focused on 50(th) percentile male. As a first step towards a better understanding of injury biomechanics in the small female, a 3D FE model of a 5(th) percentile female human chest (FEM-5F) has been developed and validated against experimental data obtained from two sets of frontal impact, one set of lateral impact, two sets of oblique impact and a series of ballistic impacts. Two previous FE models, a small female Total HUman Model for Safety (THUMS-AF05) occupant version 1.0Beta (Kimpara et al. 2002) and the Wayne State University Human Thoracic Model (WSUHTM, Wang 1995 and Shah et al. 2001) were integrated and modified for this model development. The model incorporated not only geometrical gender differences, such as location of the internal organs and structure of the bony skeleton, but also the biomechanical differences of the ribs due to gender. It includes a detailed description of the sternum, ribs, costal cartilage, thoracic spine, skin, superficial muscles, intercostal muscles, heart, lung, diaphragm, major blood vessels and simplified abdominal internal organs and has been validated against a series of six cadaveric experiments on the small female reported by Nahum et al. (1970), Kroell et al. (1974), Viano (1989), Talantikite et al. (1998) and Wilhelm (2003). Results predicted by the model were well-matched to these experimental data for a range of impact speeds and impactor masses. More research is needed in order to increase the accuracy of predicting rib fractures so that the mechanisms responsible for small female injury can be more clearly defined. PMID:17096277

  4. Freezing Rain Diagnostic Study Over Eastern Canada Using the 5th Generation Canadian Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Bresson, É.; Paquin, D.; Laprise, R.; Theriault, J. M.; de Elía, R.

    2015-12-01

    Northeastern North America is often affected by freezing rain events during the cold season. They can have significant consequences (from road accidents, to severe power outages) despite their intensity and duration. The 1998 Ice Storm over Eastern Canada and Northeastern United States is an example of an extreme event with catastrophic consequences. A total of up to 150 mm of ice accumulated during 10 days were observed in some areas. This natural disaster has highlighted the need to better understand how such phenomena will evolve with future climate scenario. The goal is to investigate the feasibility of using regional climate modeling to diagnose the occurrence of freezing rain events over Quebec (Canada). To address this issue, we used the 5th generation of the Canadian Regional Climate Model (CRCM5), from 1979 to 2014. An empirical method (Bourgouin, 2000) developed to determine the type of winter precipitations was chosen to diagnose freezing rain events. The study focused in the Montreal area and the St. Lawrence River Valley (Quebec, Canada). The sensitivity of the model to horizontal resolution was explored by using three resolutions: 0.44°, 0.22° and 0.11°. In general, freezing rain was diagnosed consistently at all resolutions but the higher one (0.11°) produced more realistic results due to a better representation of the orography. Using the higher resolution, the results showed that the climatology of the freezing rain occurrence in the Montreal area is comparable to available observations. It also suggested that the role of the specific orography of the region with the St. Lawrence River Valley can impact the characteristics of freezing rain events in this area. Overall, this study will contribute to a better preparedness for such events in the future. High resolution regional climate simulations are essential to improve the reproduction of local scale orographically-forced phenomena.

  5. A Longitudinal Study of a 5th Grade Science Curriculum Based on the 5E Model

    ERIC Educational Resources Information Center

    Scott, Timothy P.; Schroeder, Carolyn; Tolson, Homer; Huang, Tse-Yang; Williams, Omah M.

    2014-01-01

    The Center for Mathematics and Science Education at Texas A&M University contracted with Region 4 Education Service Center (ESC) and a large, diverse school district to conduct a longitudinal study from 2005-2009. The state achievement test scores of 5th graders who were taught using a Grade 5 science textbook designed by Region 4 ESC were…

  6. Validation of the 5th and 95th Percentile Hybrid III Anthropomorphic Test Device Finite Element Model

    NASA Technical Reports Server (NTRS)

    Lawrence, C.; Somers, J. T.; Baldwin, M. A.; Wells, J. A.; Newby, N.; Currie, N. J.

    2014-01-01

    NASA spacecraft design requirements for occupant protection are a combination of the Brinkley criteria and injury metrics extracted from anthropomorphic test devices (ATD's). For the ATD injury metrics, the requirements specify the use of the 5th percentile female Hybrid III and the 95th percentile male Hybrid III. Furthermore, each of these ATD's is required to be fitted with an articulating pelvis and a straight spine. The articulating pelvis is necessary for the ATD to fit into spacecraft seats, while the straight spine is required as injury metrics for vertical accelerations are better defined for this configuration. The requirements require that physical testing be performed with both ATD's to demonstrate compliance. Before compliance testing can be conducted, extensive modeling and simulation are required to determine appropriate test conditions, simulate conditions not feasible for testing, and assess design features to better ensure compliance testing is successful. While finite element (FE) models are currently available for many of the physical ATD's, currently there are no complete models for either the 5th percentile female or the 95th percentile male Hybrid III with a straight spine and articulating pelvis. The purpose of this work is to assess the accuracy of the existing Livermore Software Technology Corporation's FE models of the 5th and 95th percentile ATD's. To perform this assessment, a series of tests will be performed at Wright Patterson Air Force Research Lab using their horizontal impact accelerator sled test facility. The ATD's will be placed in the Orion seat with a modified-advanced-crew-escape-system (MACES) pressure suit and helmet, and driven with loadings similar to what is expected for the actual Orion vehicle during landing, launch abort, and chute deployment. Test data will be compared to analytical predictions and modelling uncertainty factors will be determined for each injury metric. Additionally, the test data will be used to

  7. Primary School 5th and 8th Graders' Understanding and Mental Models about the Shape of the World and Gravity

    ERIC Educational Resources Information Center

    Öztürk, Ayse; Doganay, Ahmet

    2013-01-01

    This study investigated primary school 5th and 8th graders' understanding and mental models related to the shape of the world and gravity, and how these models reflected the fact and what kind of a change there is from 5th to 8th graders. This research is based on a cross-sectional design. The study was conducted in a low socioeconomic level…

  8. Effect of Anatomical Modeling on Space Radiation Dose Estimates: A Comparison of Doses for NASA Phantoms and 5th, 50th, and 95th Percentile UF Hybrid Phantoms

    NASA Technical Reports Server (NTRS)

    Bahadori, A.; VanBaalen, M.; Shavers, M.; Semones, E.; Dodge, C.; Bolch, W.

    2010-01-01

    The estimate of absorbed dose to individual organs of a space crewmember is affected by the geometry of the anatomical model of the astronaut used in the radiation transport calculation. For astronaut dosimetry, NASA currently uses the computerized anatomical male (CAM) and computerized anatomical female (CAF) stylized phantoms to represent astronauts in its operational radiation dose analyses. These phantoms are available in one size and in two body positions. In contrast, the UF Hybrid Adult Male and Female (UFHADM and UFHADF) phantoms have organ shapes based on actual CT data. The surfaces of these phantoms are defined by non-uniform rational B-spline surfaces, and are thus flexible in terms of body morphometry and extremity positioning. In this study, UFHADM and UFHADF are scaled to dimensions corresponding to 5th, 50th, and 95th percentile (PCTL) male and female astronauts. A ray-tracing program is written in Visual Basic 2008, which is then used to create areal density maps for dose points corresponding to various organs within the phantoms. The areal density maps, along with appropriate space radiation spectra, are input into the NASA program couplet HZETRN/BRYNTRN, and organ doses are calculated. The areal density maps selected tissues and organs of the 5th, 50th, and 95th PCTL male and female phantoms are presented and compared. In addition, the organ doses for the 5th, 50th, and 95th PCTL male and female phantoms are presented and compared to organ doses for CAM and CAF.

  9. Development of a Future Representative Concentration Pathway for Use in the IPCC 5th Assessment Earth System Model Simulations

    SciTech Connect

    2010-12-29

    The representative concentration pathway to be delivered is a scenario of atmospheric concentrations of greenhouse gases and other radiatively important atmospheric species, along with land-use changes, derived from the Global Change Assessment Model (GCAM). The particular representative concentration pathway (RCP) that the Joint Global Change Research Institute (JGCRI) has been responsible for is a not-to-exceed pathway that stabilizes at a radiative forcing of 4.5Wm-2 in the year 2100.

  10. Investigation of the aerodynamic performance and noise characteristics of a 1/5th scale model of the Dowty Rotol R212 propeller

    NASA Astrophysics Data System (ADS)

    Trebble, W. J. G.

    1983-11-01

    The four-bladed Dowty Rotol R212 propeller (NACA 16 sections) was studied at 1/5th scale (0.7 m diameter) in 1.5 m acoustic tunnel. Propeller power absorption and thrust were measured over a range of rotational speeds up to 8000 rev/min at mainstream speeds from 15 to 60 m/sec for a range of blade settings. Slipstream wake surveys show outward movement of the position of the peak pressure as propeller loading is increased. Noise analysis demonstrates the predominance of multiple tones whose number and intensity increase with helical-tip Mach number. An empirical formula shows that the fundamental tone sound pressure level varies with tip speed and power loading in an identical manner to that observed on an ARA-D section propeller.

  11. 168. GENERAL VIEW FROM 5TH AVE. VIEW SOUTH, ACROSS 5TH ...

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

    168. GENERAL VIEW FROM 5TH AVE. VIEW SOUTH, ACROSS 5TH AVE., TOWARD BUILDING 506 (ON LEFT) AND BUILDING 435. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  12. Kids & Family Reading Report™. 5th Edition

    ERIC Educational Resources Information Center

    Scholastic Inc., 2015

    2015-01-01

    This report presents the 5th Edition of Scholastic's biannual study of children's and parents' attitudes and behaviors about reading. The latest research touches on reading aloud to children of all ages, the impact of reading independently for fun at school and at home, the importance of frequent reading, and the books children want most to read.…

  13. BOOK REVIEW: ENVIRONMENTAL ENGINEERING, 5TH EDITION

    EPA Science Inventory

    Book Review of Environmental Engineering, 5th Edition (Joseph A. Salvato, Nelson L. Nemerow, Franklin J. Agardy (Editors), John Wiley and Sons, Inc. Hoboken, New Jersey. 2003.). Author wrote review per the request of the Editor-in-Chief of the Journal of Environmental Quality.

  14. Multifrequency Catalogue of Blazars - 5th Edition

    NASA Astrophysics Data System (ADS)

    Massaro, E.; Maselli, A.; Leto, C.; Marchegiani, P.; Perri, M.; Giommi, P.; Piranomonte, S.

    2014-12-01

    The 5th Edition of the Multifrequency Catalogue of Blazars is one of the most complete lists of Active Galactic Nuclei whose emission properties are recognised as typical of blazars. It includes the list of sources and an essential compilation of multifrequency data from radio to gamma rays. The source list for the entire sky is also available online at the ASDC web site (http://www.asdc.asi.it/bzcat/) where it is frequently updated to add new blazars and to improve the database.

  15. The effect of anatomical modeling on space radiation dose estimates: a comparison of doses for NASA phantoms and the 5th, 50th, and 95th percentile male and female astronauts

    NASA Astrophysics Data System (ADS)

    Bahadori, Amir A.; Van Baalen, Mary; Shavers, Mark R.; Dodge, Charles; Semones, Edward J.; Bolch, Wesley E.

    2011-03-01

    The National Aeronautics and Space Administration (NASA) performs organ dosimetry and risk assessment for astronauts using model-normalized measurements of the radiation fields encountered in space. To determine the radiation fields in an organ or tissue of interest, particle transport calculations are performed using self-shielding distributions generated with the computer program CAMERA to represent the human body. CAMERA mathematically traces linear rays (or path lengths) through the computerized anatomical man (CAM) phantom, a computational stylized model developed in the early 1970s with organ and body profiles modeled using solid shapes and scaled to represent the body morphometry of the 1950 50th percentile (PCTL) Air Force male. With the increasing use of voxel phantoms in medical and health physics, a conversion from a mathematical-based to a voxel-based ray-tracing algorithm is warranted. In this study, the voxel-based ray tracer (VoBRaT) is introduced to ray trace voxel phantoms using a modified version of the algorithm first proposed by Siddon (1985 Med. Phys. 12 252-5). After validation, VoBRAT is used to evaluate variations in body self-shielding distributions for NASA phantoms and six University of Florida (UF) hybrid phantoms, scaled to represent the 5th, 50th, and 95th PCTL male and female astronaut body morphometries, which have changed considerably since the inception of CAM. These body self-shielding distributions are used to generate organ dose equivalents and effective doses for five commonly evaluated space radiation environments. It is found that dosimetric differences among the phantoms are greatest for soft radiation spectra and light vehicular shielding.

  16. Some mice feature 5th pharyngeal arch arteries and double-lumen aortic arch malformations.

    PubMed

    Geyer, Stefan H; Weninger, Wolfgang J

    2012-01-01

    A 5th pair of pharyngeal arch arteries (PAAs) has never been identified with certainty in mice. Murines in general are considered to not develop a 5th pair. If true, the significance of the mouse as a model for researching the genesis of malformations of the great intrathoracic arteries is limited. We aimed to investigate whether mouse embryos develop a 5th pair of PAAs and to identify malformations known to be caused by defective remodelling of the 5th PAAs. We employed the high-resolution episcopic microscopy method for creating digital volume data and three-dimensional (3D) computer models of the great intrathoracic arteries of 30 mouse embryos from days 12-12.5 post conception and 180 mouse fetuses from days 14.5 and 15.5 post conception. The 3D models of the fetuses were screened for the presence of a double-lumen aortic arch malformation. We identified such a malformation in 1 fetus. The 3D models of the embryos were analysed for the presence of 5th PAAs. Six of the 30 embryos (20%) showed a 5th PAA bilaterally, and an additional 9 (30%) showed a 5th PAA unilaterally. Our results prove that some mice do develop a 5th pair of PAAs. They also show that malformations which occur rarely in humans and result from defective remodelling of the left 5th PAA can be identified in mice as well. Thus, the mouse does represent an excellent model for researching the mechanisms driving PAA remodelling and the genesis of malformations of the great intrathoracic arteries. PMID:22287557

  17. Uncertainty Analysis of Model Coupling

    NASA Astrophysics Data System (ADS)

    Held, H.; Knopf, B.; Schneider von Deimling, T.; Schellnhuber, H.-J.

    The Earth System is a highly complex system that is often modelled by coupling sev- eral nonlinear submodules. For predicting the climate with these models, the following uncertainties play an essential role: parameter uncertainty, uncertainty in initial con- ditions or model uncertainty. Here we will address uncertainty in initial conditions as well as model uncertainty. As the process of coupling is an important part of model- ing, the main aspect of this work is the investigation of uncertainties that are due to the coupling process. For this study we use conceptual models that, compared to GCMs, have the advantage that the model itself as well as the output can be treated in a mathematically elabo- rated way. As the time for running the model is much shorter, the investigation is also possible for a longer period, e.g. for paleo runs. In consideration of these facts it is feasible to analyse the whole phase space of the model. The process of coupling is investigated by using different methods of examining low order coupled atmosphere-ocean systems. In the dynamical approach a fully coupled system of the two submodules can be compared to a system where one submodule forces the other. For a particular atmosphere-ocean system, based on the Lorenz model for the atmosphere, there can be shown significant differences in the predictability of a forced system depending whether the subsystems are coupled in a linear or a non- linear way. In [1] it is shown that in the linear case the forcing cannot represent the coupling, but in the nonlinear case, that we investigated in our study, the variability and the statistics of the coupled system can be reproduced by the forcing. Another approach to analyse the coupling is to carry out a bifurcation analysis. Here the bifurcation diagram of a single atmosphere system is compared to that of a cou- pled atmosphere-ocean system. Again it can be seen from the different behaviour of the coupled and the uncoupled system, that the

  18. 5TH BIOTECHNOLOGICAL INVESTIGATIONS OCEAN MARGINS PROGRAM

    SciTech Connect

    DR. ARTURO MASSOL, PROGRAM CHAIR; DR. ROSA BUXEDA, PROGRAM CO-CHAIR

    2004-01-08

    BI-OMP supports DOE's mission in Climate Change Research. The program provides the fundamental understanding of the linkages between carbon and nitrogen cycles in ocean margins. Researchers are providing a mechanistic understanding of these cycles, using the tools of modern molecular biology. The models that will allow policy makers to determine safe levels of greenhouse gases for the Earth System.

  19. The Effects of Reading from the Screen on the Reading Motivation Levels of Elementary 5th Graders

    ERIC Educational Resources Information Center

    Aydemir, Zeynep; Ozturk, Ergun

    2012-01-01

    This study aims to explore the effects of reading from the screen on elementary 5th grade students' reading motivation levels. It used the randomized control-group pretest-posttest model, which is a true experimental design. The study group consisted of 60 students, 30 experimental and 30 control, who were attending the 5th grade of a public…

  20. Overlay improvement by ASML HOWA 5th alignment strategy

    NASA Astrophysics Data System (ADS)

    Wang, Raf; Chiang, CY; Hsu, Wilson; Yang, Richer; Shih, Todd; Chen, Jackie; Chiu, Jonathan; Lin, Wythe

    2009-12-01

    Overlay control is more challenging when DRAM volume production continues to shrink its critical dimention (CD) to 70nm and beyond. Effected by process, the overlay behavior at wafer edge is quite different from wafer center. The big contribution to worse overlay at wafer edge which causes yield loss is misalignment. The analysis in wafer edge suggests that high order uncorrectable overlay residuals are often observed by certain process impact. Therefore, the basic linear model used for alignment correction is not sufficient and it is necessary to introduce an advanced alignment correction model for wafer edge overlay improvement. In this study, we demonstrated the achievement of moderating the poor overlay at wafer edge area by using a high order wafer alignment strategy. The mechanism is to use non-linear correction methods of high order models ( up to 5th order), with support by the function High Order Wafer Alignment (known as HOWA) in scanner. Instead of linear model for the 6 overlay parameters which come from average result, HOWA alignment strategy can do high order fitting through the wafer to get more accurate overlay parameters which represent the local wafer grid distortion better. As a result, the overlay improvement for wafer edge is achieved. Since alignment is a wafer dependent correction, with HOWA the wafer to wafer overlay variation can be improved dynamically as well. In addition, the effects of different mark quantity and sampling distribution from HOWA are also introduced in this paper. The results of this study indicate that HOWA can reduce uncorrectable overlay residual by 30~40% and improve wafer-to-wafer overlay variation significantly. We conclude that HOWA is a noteworthy strategy for overlay improvement. Moreover, optimized alignment mark numbers and distribution layout are also key factors to make HOWA successful.

  1. The Effect of Progressive Sentence Development Activities on 5th Graders' Description Skills

    ERIC Educational Resources Information Center

    Hamzadayi, Ergun

    2015-01-01

    The aim of this study was to examine the effect of progressive sentence development activities on 5th graders' description skills. The study was conducted based on the pretest-posttest quasi-experimental model with a control group. A total of 58 students participated in the study; 29 in the control group, and 29 in the experimental group. The…

  2. Session on coupled atmospheric/chemistry coupled models

    NASA Technical Reports Server (NTRS)

    Thompson, Anne

    1993-01-01

    The session on coupled atmospheric/chemistry coupled models is reviewed. Current model limitations, current issues and critical unknowns, and modeling activity are addressed. Specific recommendations and experimental strategies on the following are given: multiscale surface layer - planetary boundary layer - chemical flux measurements; Eulerian budget study; and Langrangian experiment. Nonprecipitating cloud studies, organized convective systems, and aerosols - heterogenous chemistry are also discussed.

  3. Working Together for Student Achievement. 5th Biennial Joint Report

    ERIC Educational Resources Information Center

    Washington State Board of Education, 2014

    2014-01-01

    The Washington state Board of Education (SBE) and the Professional Educator Standards Board (PESB) submitted this 5th biennial joint report to the Governor, Legislative Education Committees, and Superintendent of Public Instruction. The report outlines the collaborative work of the Boards, highlights accomplishments, and provides goals and…

  4. 5th Conference on Aerospace Materials, Processes, and Environmental Technology

    NASA Technical Reports Server (NTRS)

    Cook, M. B. (Editor); Stanley, D. Cross (Editor)

    2003-01-01

    Records are presented from the 5th Conference on Aerospace Materials, Processes, and Environmental Technology. Topics included pollution prevention, inspection methods, advanced materials, aerospace materials and technical standards,materials testing and evaluation, advanced manufacturing,development in metallic processes, synthesis of nanomaterials, composite cryotank processing, environmentally friendly cleaning, and poster sessions.

  5. 5th Latin American pesticide residue workshop (LAPRW 2015)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This invited editorial proceedings article introduces the 6 research papers published in the special topical collection for the 5th Latin American Pesticide Residue Workshop held in Santiago, Chile, May 10-13, 2015. The meeting was a great success with more than 50 talks, 140 posters, 21 vendors, a...

  6. Teaching 5th grade science for aesthetic understanding

    NASA Astrophysics Data System (ADS)

    Girod, Mark A.

    Many scientists speak with great zeal about the role of aesthetics and beauty in their science and inquiry. Few systematic efforts have been made to teach science in ways that appeal directly to aesthetics and this research is designed to do just that. Drawing from the aesthetic theory of Dewey, I describe an analytic lens called learning for aesthetic understanding that finds power in the degree to which our perceptions of the world are transformed, our interests and enthusiasm piqued, and our actions changed as we seek further experiences in the world. This learning theory is contrasted against two other current and popular theories of science learning, that of learning for conceptual understanding via conceptual change theory and learning for a language-oriented or discourse-based understanding. After a lengthy articulation of the pedagogical strategies used to teach for aesthetic understanding the research is described in which comparisons are drawn between students in two 5th grade classrooms---one taught for the goal of conceptual understanding and the other taught for the goal of aesthetic understanding. Results of this comparison show that more students in the treatment classroom had aesthetic experiences with science ideas and came to an aesthetic understanding when studying weather, erosion, and structure of matter than students in the control group. Also statistically significant effects are shown on measures of interest, affect, and efficacy for students in the treatment class. On measures of conceptual understanding it appears that treatment class students learned more and forgot less over time than control class students. The effect of the treatment does not generally depend on gender, ethnicity, or prior achievement except in students' identity beliefs about themselves as science learners. In this case, a significant interaction for treatment class females on science identity beliefs did occur. A discussion of these results as well as elaboration and

  7. The Challenges to Coupling Dynamic Geospatial Models

    SciTech Connect

    Goldstein, N

    2006-06-23

    Many applications of modeling spatial dynamic systems focus on a single system and a single process, ignoring the geographic and systemic context of the processes being modeled. A solution to this problem is the coupled modeling of spatial dynamic systems. Coupled modeling is challenging for both technical reasons, as well as conceptual reasons. This paper explores the benefits and challenges to coupling or linking spatial dynamic models, from loose coupling, where information transfer between models is done by hand, to tight coupling, where two (or more) models are merged as one. To illustrate the challenges, a coupled model of Urbanization and Wildfire Risk is presented. This model, called Vesta, was applied to the Santa Barbara, California region (using real geospatial data), where Urbanization and Wildfires occur and recur, respectively. The preliminary results of the model coupling illustrate that coupled modeling can lead to insight into the consequences of processes acting on their own.

  8. Coupled transport in rotor models

    NASA Astrophysics Data System (ADS)

    Iubini, S.; Lepri, S.; Livi, R.; Politi, A.

    2016-08-01

    Steady nonequilibrium states are investigated in a one-dimensional setup in the presence of two thermodynamic currents. Two paradigmatic nonlinear oscillators models are investigated: an XY chain and the discrete nonlinear Schrödinger equation. Their distinctive feature is that the relevant variable is an angle in both cases. We point out the importance of clearly distinguishing between energy and heat flux. In fact, even in the presence of a vanishing Seebeck coefficient, a coupling between (angular) momentum and energy arises, mediated by the unavoidable presence of a coherent energy flux. Such a contribution is the result of the ‘advection’ induced by the position-dependent angular velocity. As a result, in the XY model, the knowledge of the two diagonal elements of the Onsager matrix suffices to reconstruct its transport properties. The analysis of the nonequilibrium steady states finally allows to strengthen the connection between the two models.

  9. A multilingual programming model for coupled systems.

    SciTech Connect

    Ong, E. T.; Larson, J. W.; Norris, B.; Tobis, M.; Steder, M.; Jacob, R. L.; Mathematics and Computer Science; Univ. of Wisconsin; Univ. of Chicago; The Australian National Univ.

    2008-01-01

    Multiphysics and multiscale simulation systems share a common software requirement-infrastructure to implement data exchanges between their constituent parts-often called the coupling problem. On distributed-memory parallel platforms, the coupling problem is complicated by the need to describe, transfer, and transform distributed data, known as the parallel coupling problem. Parallel coupling is emerging as a new grand challenge in computational science as scientists attempt to build multiscale and multiphysics systems on parallel platforms. An additional coupling problem in these systems is language interoperability between their constituent codes. We have created a multilingual parallel coupling programming model based on a successful open-source parallel coupling library, the Model Coupling Toolkit (MCT). This programming model's capabilities reach beyond MCT's native Fortran implementation to include bindings for the C++ and Python programming languages. We describe the method used to generate the interlanguage bindings. This approach enables an object-based programming model for implementing parallel couplings in non-Fortran coupled systems and in systems with language heterogeneity. We describe the C++ and Python versions of the MCT programming model and provide short examples. We report preliminary performance results for the MCT interpolation benchmark. We describe a major Python application that uses the MCT Python bindings, a Python implementation of the control and coupling infrastructure for the community climate system model. We conclude with a discussion of the significance of this work to productivity computing in multidisciplinary computational science.

  10. 5th Annual Global College of Neuroprotection and Neuroregeneration.

    PubMed

    Sharma, Hari Shanker

    2008-06-01

    The 5th Global College of Neuroprotection and Neuroregeneration (GCNN) was held in the historic charming capital city of Bucharest, Romania in JW Marriott Grand Hotel on 3-6 March, 2008. The meeting was a unique blend of basic researchers and clinicians across the Globe presenting their recent findings in neuroprotection and neuroregeneration in a beautiful exotic ambience. More than 300 students and researchers attended the congress and participated in deliberations. Over 60 representatives from various pharmaceutical industries from all over the world supported this event. This meeting was held for the first time as a joint venture with GCNN and the Society for study on Neuroproetction and Neuroplasticity (SSNN), and was a grand success both scientifically and socially. Thus, these joint meetings of the two societies (GCNN and SSNN) will continue in future in different European cities for the coming 5 years. PMID:18505353

  11. 167. GENERAL VIEW DOWN 5TH AVE. VIEW TO SOUTHWEST DOWN ...

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

    167. GENERAL VIEW DOWN 5TH AVE. VIEW TO SOUTHWEST DOWN 5TH AVE. SHOWING FROM LEFT TO RIGHT, BUILDING 504, 436, 11, AND 155. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  12. Convectively coupled Kelvin waves in CMIP5 coupled climate models

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Li, Tim

    2016-04-01

    This study provided a quantitative evaluation of convectively coupled Kelvin waves (CCKWs) over the Indian Ocean and the Pacific Ocean simulated by 20 coupled climate models that participated in Coupled Model Intercomparison Project phase 5. The two leading empirical orthogonal function (EOF) modes of filtered daily precipitation anomalies are used to represent the eastward propagating CCKWs in both observations and simulations. The eigenvectors and eigenvalues of the EOF modes represent the spatial patterns and intensity of CCKWs respectively, and the lead-lag relationship between the two EOF principle components describe the phase propagation of CCKWs. A non-dimensional metric was designed in consideration of all the three factors (i.e., pattern, amplitude and phase propagation) for evaluation. The relative rankings of the models based on the skill scores calculated by the metric are conducted for the Indian Ocean and the Pacific Ocean, respectively. Two models (NorESM1-M and MPI-ESM-LR) are ranked among the best 20 % for both the regions. Three models (inmcm4, MRI-CGCM3 and HadGEM2-ES) are ranked among the worst 20 % for both the regions. While the observed CCKW amplitude is greater north of the equator in the Pacific, some models overestimate the CCKW ampliutde in the Southern Hemisphere. This bias is related to the mean state precipitation bias along the south Pacific convergence zone.

  13. PREFACE: 5th Baltic Conference on Silicate Materials

    NASA Astrophysics Data System (ADS)

    Mezinskis, G.; Bragina, L.; Colombo, P.; Frischat, G. H.; Grabis, J.; Greil, P.; Deja, J.; Kaminskas, R.; Kliava, J.; Medvids, A.; Nowak, I.; Siauciunas, R.; Valancius, Z.; Zalite, I.

    2011-12-01

    Logo This Volume of IOP Conference Series: Materials Science and Engineering presents a selection of the contributions to the 5th Baltic Conference on Silicate Materials (BaltSilica2011) held at Riga Technical University, Riga, Latvia from 23-25 May 2011. The conference was organized by Riga Technical University (Latvia) and Kaunas University of Technology (Lithuania). The series of Baltic conferences on silicate materials was started since 2004: the first conference was held in Riga, Latvia, 2004; the second conference was held in Kaunas, Lithuania 2005; the third was held again in Riga, Latvia, 2007, and the fourth was held in Kaunas, Lithuania 2009. BaltSilica 2011 was attended by around 50 participants from Latvia, Lithuania, Estonia, Germany, Poland, Italy, France, Ukraine and Russia. In comparison with previous silicate materials conferences, the broadening of participating countries is an indication of the interest of scientists, engineers and students to exchange research ideas, latest results, and to find new research topics for cooperation in the fields of silicate, high temperature materials, and inorganic nanomaterials. The scientific programme included 8 invited plenary lectures 23 oral presentations and 25 posters [1]. Scientific themes covered in the conference and in this special issue: Natural and Artificial Stone Materials; Traditional and New Ceramic and Glass-Like Materials; Nanoparticles and Nanomaterials. This volume consists of 23 selected proceeding papers. The Editor of this special issue is grateful to all the contributors to BaltSilica 2011. I am also very grateful to the scientific committee, the local organizing committee, the session chairs, the referees who refereed the submitted articles to this issue, and to students from the Department of Silicate, High Temperature and Inorganic Nanomaterials Technology of the Riga Technical University who ensured the smooth running of the conference. Particular thanks goes to eight plenary

  14. Managing Haemophilia for Life: 5th Haemophilia Global Summit.

    PubMed

    Hermans, Cedric; Dolan, Gerry; Jennings, Ian; Windyga, Jerzy; Lobet, Sébastien; Rodríguez-Merchán, E Carlos; Di Minno, Matteo Nicola Dario; Jiménez-Yuste, Víctor; O'Mahony, Brian

    2015-10-01

    The 5th Haemophilia Global Summit was held in Barcelona, Spain, in September 2014. The programme was designed by an independent Scientific Steering Committee of haemophilia experts and explored issues relevant to the practical management of haemophilia, as well as key opportunities and challenges for care in the future. The topics outlined in this supplement were selected by the Scientific Steering Committee for their relevance to improving haemophilia care globally. In this supplement from the meeting, Gerry Dolan explores pharmacokinetics and dynamics in haemophilia, and Gerry Dolan and Ian Jennings jointly address the role of the laboratory in haemophilia care. The potential benefits of low-dose prophylaxis regimens for people with haemophilia in the developing world are reviewed by Jerzy Windyga, and the question of whether 'Future haemophilia research should be undertaken in the developing world' is debated by Jerzy Windyga and Cedric Hermans. Management strategies for ankle arthropathy are discussed by Sébastien Lobet and E. Carlos Rodríguez-Merchán, and the use of ultrasound for the early detection of haemophilic arthropathy is addressed by Matteo Nicola Dario Di Minno and Víctor Jiménez-Yuste. Finally, the role of patients in the future of haemophilia care is reviewed by Brian O'Mahony. PMID:26350039

  15. Coupling environmental models and geospatial data processing

    NASA Astrophysics Data System (ADS)

    Brandmeyer, Jo Ellen

    2000-10-01

    This research investigated geospatial functions for solving environmental problems from the perspective of the environmental modeler. Its purpose is to better understand the different approaches to coupling complex models and geospatial data processing, plus the implications for the coupled system. To this end, various coupling methodologies were systematically explored using a geographic information system (GIS) and an emissions processor (SMOKE) for air quality models (AQMs). SMOKE converts an emissions inventory into the format required by an AQM. A GIS creates a file describing the spatial distribution of emissions among the cells in a modeling domain. To demonstrate advantages of a coupled GIS---environmental model system, two methods of spatially distributing on-road mobile emissions to cells were examined. The existing method calculates emissions for each road class, but distributes emissions to the cells using population density. For the new method a GIS builds road density by class and then distributes the emissions using road density. Comparing these methods reveals a significantly different spatial pattern of emissions. Next, various model-coupling methodologies were analyzed, revealing numerous coupling approaches, some of which were categorized in the literature. Critiquing these categorizations while comparing them with documented implementations led to the development of a new coupling hierarchy. The properties of each hierarchical level are discussed with the advantages and limitations of each design. To successfully couple models, the spatial and temporal scales of all models in the coupled system and the spatiotemporal extents of the data must be reconciled. Finally, a case study demonstrated methodologies for coupling SMOKE and a GIS. One methodology required a new approach utilizing dynamically linked libraries. Consequently, emissions were processed using SMOKE from a GIS. Also, a new method of converting data from netCDF files into a database

  16. APTWG: The 5th Asia-Pacific Transport Working Group Meeting

    NASA Astrophysics Data System (ADS)

    Gao, X.; Ghim, Y.-C.; Sun, Y. W.; Gao, Z.; Inagaki, S.; Chen, W.; Zhang, T.; Wang, Z. X.

    2016-03-01

    This conference report gives a summary on the contributed papers and discussions presented at the 5th Asia-Pacific Transport Working Group Meeting held at Dalian, China from 9-12 June 2015. The main goal of the working group is to develop a predictive understanding of the basic mechanisms responsible for particle, momentum and energy transport in magnetically confined plasmas. The topics of the meeting in 2015 were organized under five main headings: (1) turbulence suppression and transport barrier formation, (2) effect of magnetic topology on MHD activity and transport, (3) non-diffusive contribution of momentum and particle transport, (4) non-local transport and turbulence spreading and coupling and (5) energetic particles and instability. The Young Researchers’ Forum which was held at this meeting is also described in this report.

  17. Dynamic coupling of three hydrodynamic models

    NASA Astrophysics Data System (ADS)

    Hartnack, J. N.; Philip, G. T.; Rungoe, M.; Smith, G.; Johann, G.; Larsen, O.; Gregersen, J.; Butts, M. B.

    2008-12-01

    The need for integrated modelling is evidently present within the field of flood management and flood forecasting. Engineers, modellers and managers are faced with flood problems which transcend the classical hydrodynamic fields of urban, river and coastal flooding. Historically the modeller has been faced with having to select one hydrodynamic model to cover all the aspects of the potentially complex dynamics occurring in a flooding situation. Such a single hydrodynamic model does not cover all dynamics of flood modelling equally well. Thus the ideal choice may in fact be a combination of models. Models combining two numerical/hydrodynamic models are becoming more standard, typically these models combine a 1D river model with a 2D overland flow model or alternatively a 1D sewer/collection system model with a 2D overland solver. In complex coastal/urban areas the flood dynamics may include rivers/streams, collection/storm water systems along with the overland flow. The dynamics within all three areas is of the same time scale and there is feedback in the system across the couplings. These two aspects dictate a fully dynamic three way coupling as opposed to running the models sequentially. It will be shown that the main challenges of the three way coupling are time step issues related to the difference in numerical schemes used in the three model components and numerical instabilities caused by the linking of the model components. MIKE FLOOD combines the models MIKE 11, MIKE 21 and MOUSE into one modelling framework which makes it possible to couple any combination of river, urban and overland flow fully dynamically. The MIKE FLOOD framework will be presented with an overview of the coupling possibilities. The flood modelling concept will be illustrated through real life cases in Australia and in Germany. The real life cases reflect dynamics and interactions across all three model components which are not possible to reproduce using a two-way coupling alone. The

  18. PREFACE: 5th Workshop of Young Researchers in Astronomy & Astrophysics

    NASA Astrophysics Data System (ADS)

    Forgács-Dajka, Emese; Plachy, Emese; Molnár, László

    2010-04-01

    The 5th Workshop of Young Researchers in Astronomy and Astrophysics was held on 2-4 September 2009 at the Eötvös University in Budapest, Hungary. This meeting fits into a conference series which can already be considered a tradition where the younger generation has the opportunity to present their work. The event was also a great opportunity for senior astronomers and physicists to form new connections with the next generation of researchers. The selection of invited speakers concentrated on the researchers currently most active in the field, mostly on a post-doctoral/tenure/fresh faculty position level. A number of senior experts and PhD students were also invited. As the conference focused on people rather than a specific field, various topics from theoretical physics to planetology were covered in three days. The programme was divided into six sections: Physics of the Sun and the Solar System Gravity and high-energy physics Galactic and extragalactic astronomy, cosmology Celestial mechanics and exoplanets Infrared astronomy and young stars Variable stars We had the pleasure of welcoming 10 invited review talks from senior researchers and 42 contributed talks and a poster from the younger generation. Participants also enjoyed the hospitality of the pub Pál at the Pálvölgyi-cave after giving, hearing and disputing countless talks. Brave souls even descended to the unbuilt, adventurous Mátyásvölgyi-cave. Memories of the conference were shadowed though. Péter Csizmadia, one of our participants and three other climbers attempted a first ever ascent to the Ren Zhong Feng peak in Sichuan, China, but they never returned from the mountains. Péter departed to China shortly after the conference, with best wishes from participants and friends. We dedicate this volume to his memory. The organisers thankthe Physics Doctoral School of Eötvös University for its hospitality. The workshop was supported by the Mecenatúra and Polányi Mihály Programmes of the National

  19. How much of the NAO monthly variability is from ocean-atmospheric coupling: results from an interactive ensemble climate model

    NASA Astrophysics Data System (ADS)

    Xin, Xiaoge; Xue, Wei; Zhang, Minghua; Li, Huimin; Zhang, Tao; Zhang, Jie

    2015-02-01

    The chaotic atmospheric circulations and the ocean-atmosphere coupling may both cause variations in the North Atlantic Oscillation (NAO). This study uses an interactive ensemble (IE) coupled model to study the contribution of the atmospheric noise and coupling to the monthly variability of the NAO. In the IE model, seven atmospheric general circulation model (AGCM) realizations with different initial states are coupled with a single realization of the land, ocean and ice component models. The chaotic noise from the atmosphere at the air-sea interface is therefore reduced. The time variances of monthly NAO index in the ensemble AGCM mean of the IE model is found to be about 20.1 % of that in the SC model. Therefore, more than 79.9 % of the simulated monthly variability of NAO is caused by atmospheric noise. The coupling between sea surface temperature (SST) and NAO is only found in regions south of about 40°N in the North Atlantic Ocean. The IE strategy highlighted the interaction between the NAO and the SST in the region (28°-38°N, 20°W-50°W) to the southeast of the Gulf Stream extension. While the ocean-atmosphere coupling explains <1/5th of the NAO variability in the IE model, it shows slightly larger persistence than the SC model, consistent with the hypothesis of a slower mode of variability from ocean-atmosphere coupling that has larger predictability than the variability driven by the atmosphere.

  20. Coupled wake boundary layer model of windfarms

    NASA Astrophysics Data System (ADS)

    Stevens, Richard; Gayme, Dennice; Meneveau, Charles

    2014-11-01

    We present a coupled wake boundary layer (CWBL) model that describes the distribution of the power output in a windfarm. The model couples the traditional, industry-standard wake expansion/superposition approach with a top-down model for the overall windfarm boundary layer structure. Wake models capture the effect of turbine positioning, while the top-down approach represents the interaction between the windturbine wakes and the atmospheric boundary layer. Each portion of the CWBL model requires specification of a parameter that is unknown a-priori. The wake model requires the wake expansion rate, whereas the top-down model requires the effective spanwise turbine spacing within which the model's momentum balance is relevant. The wake expansion rate is obtained by matching the mean velocity at the turbine from both approaches, while the effective spanwise turbine spacing is determined from the wake model. Coupling of the constitutive components of the CWBL model is achieved by iterating these parameters until convergence is reached. We show that the CWBL model predictions compare more favorably with large eddy simulation results than those made with either the wake or top-down model in isolation and that the model can be applied successfully to the Horns Rev and Nysted windfarms. The `Fellowships for Young Energy Scientists' (YES!) of the Foundation for Fundamental Research on Matter supported by NWO, and NSF Grant #1243482.

  1. The utility of a 5th nap in multiple sleep latency test

    PubMed Central

    Lykouras, Dimosthenis; Rees, Kate

    2016-01-01

    Background This is the first study that aimed to look specifically at the utility of the 5th nap in the multiple sleep latency test (MSLT), a test used to assist in the diagnosis of narcolepsy. Methods Data was retrospectively collected from the Sleep Disorders Centre of a Tertiary Hospital on patients that had a 5th nap during their MSLT from the 08th November 2011 to 12th November 2014. Results Fifty-three patients had a 5th nap performed out of 378 MSLT studies. In 16% of cases a diagnosis of narcolepsy was given directly due to the inclusion of the 5th nap on the MSLT. Here a 5th nap allowed diagnostic criteria of mean sleep latency <8 minutes and >2 SOREMPS to be met. In 53% of cases the mean sleep latency increased due to 5th nap inclusion; the mean sleep latency of the first four naps was 5.6 vs. 6.7 after inclusion of the 5th nap. Conclusions The 5th nap is not often performed within the MSLT studies. Our study shows that only a few patients may benefit from a 5th nap opportunity which also led to increase of the mean sleep latency at the expense of extra time, cost, labour and increased patient anxiety. PMID:26904269

  2. An Appraisal of Coupled Climate Model Simulations

    SciTech Connect

    Sperber, K; Gleckler, P; Covey, C; Taylor, K; Bader, D; Phillips, T; Fiorino, M; Achutarao, K

    2004-02-24

    In 2002, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) proposed the concept for a state-of-the-science appraisal of climate models to be performed approximately every two years. Motivation for this idea arose from the perceived needs of the international modeling groups and the broader climate research community to document progress more frequently than provided by the Intergovernmental Panel on Climate Change (IPCC) Assessment Reports. A committee of external reviewers, which included senior researchers from four leading international modeling centers, supported the concept by stating in its review: ''The panel enthusiastically endorses the suggestion that PCMDI develop an independent appraisal of coupled model performance every 2-3 years. This would provide a useful 'mid-course' evaluation of modeling progress in the context of larger IPCC and national assessment activities, and should include both coupled and single-component model evaluations.''

  3. Model reduction for networks of coupled oscillators

    NASA Astrophysics Data System (ADS)

    Gottwald, Georg A.

    2015-05-01

    We present a collective coordinate approach to describe coupled phase oscillators. We apply the method to study synchronisation in a Kuramoto model. In our approach, an N-dimensional Kuramoto model is reduced to an n-dimensional ordinary differential equation with n ≪ N , constituting an immense reduction in complexity. The onset of both local and global synchronisation is reproduced to good numerical accuracy, and we are able to describe both soft and hard transitions. By introducing two collective coordinates, the approach is able to describe the interaction of two partially synchronised clusters in the case of bimodally distributed native frequencies. Furthermore, our approach allows us to accurately describe finite size scalings of the critical coupling strength. We corroborate our analytical results by comparing with numerical simulations of the Kuramoto model with all-to-all coupling networks for several distributions of the native frequencies.

  4. Playing with fermion couplings in Higgsless models

    SciTech Connect

    Casalbuoni, R.; De Curtis, S.; Dolce, D.; Dominici, D.

    2005-04-01

    We discuss the fermion couplings in a four dimensional SU(2) linear moose model by allowing for direct couplings between the left-handed fermions on the boundary and the gauge fields in the internal sites. This is realized by means of a product of nonlinear {sigma}-model scalar fields which, in the continuum limit, is equivalent to a Wilson line. The effect of these new nonlocal couplings is a contribution to the {epsilon}{sub 3} parameter which can be of opposite sign with respect to the one coming from the gauge fields along the string. Therefore, with some fine-tuning, it is possible to satisfy the constraints from the electroweak data.

  5. Simplified coupling power model for fibers fusion

    NASA Astrophysics Data System (ADS)

    Saktioto, J.; Ali, J.; Fadhali, M.

    2009-09-01

    Fiber coupler fabrication used for an optical waveguide requires lossless power for an optimal application. The previous research coupled fibers were successfully fabricated by injecting hydrogen flow at 1 bar and fused slightly by unstable torch flame in the range of 800-1350°C. Optical parameters may vary significantly over wide range physical properties. Coupling coefficient and refractive index are estimated from the experimental result of the coupling ratio distribution from 1% to 75%. The change of geometrical fiber affects the normalized frequency V even for single mode fibers. V is derived and some parametric variations are performed on the left and right hand side of the coupling region. A partial power is modelled and derived using V, normalized lateral phase constant u, and normalized lateral attenuation constant, w through the second kind of modified Bessel function of the l order, which obeys the normal mode and normalized propagation constant b. Total power is maintained constant in order to comply with the energy conservation law. The power is integrated through V, u, and w over the pulling length of 7500 µm for 1-D. The core radius of a fiber significantly affects V and power partially at coupling region rather than wavelength and refractive index of core and cladding. This model has power phenomena in transmission and reflection for an optical switch and tunable filter.

  6. Parallelization of the Coupled Earthquake Model

    NASA Technical Reports Server (NTRS)

    Block, Gary; Li, P. Peggy; Song, Yuhe T.

    2007-01-01

    This Web-based tsunami simulation system allows users to remotely run a model on JPL s supercomputers for a given undersea earthquake. At the time of this reporting, predicting tsunamis on the Internet has never happened before. This new code directly couples the earthquake model and the ocean model on parallel computers and improves simulation speed. Seismometers can only detect information from earthquakes; they cannot detect whether or not a tsunami may occur as a result of the earthquake. When earthquake-tsunami models are coupled with the improved computational speed of modern, high-performance computers and constrained by remotely sensed data, they are able to provide early warnings for those coastal regions at risk. The software is capable of testing NASA s satellite observations of tsunamis. It has been successfully tested for several historical tsunamis, has passed all alpha and beta testing, and is well documented for users.

  7. The Coupled Model Intercomparison Project (CMIP).

    NASA Astrophysics Data System (ADS)

    Meehl, Gerald A.; Boer, George J.; Covey, Curt; Latif, Mojib; Stouffer, Ronald J.

    2000-02-01

    The Coupled Model Intercomparison Project (CMIP) was established to study and intercompare climate simulations made with coupled ocean-atmosphere-cryosphere-land GCMs. There are two main phases (CMIP1 and CMIP2), which study, respectively, 1) the ability of models to simulate current climate, and 2) model simulations of climate change due to an idealized change in forcing (a 1% per year CO2 increase). Results from a number of CMIP projects were reported at the first CMIP Workshop held in Melbourne, Australia, in October 1998. Some recent advances in global coupled modeling related to CMIP were also reported. Presentations were based on preliminary unpublished results. Key outcomes from the workshop were that 1) many observed aspects of climate variability are simulated in global coupled models including the North Atlantic oscillation and its linkages to North Atlantic SSTs, El Niño-like events, and monsoon interannual variability; 2) the amplitude of both high- and low-frequency global mean surface temperature variability in many global coupled models is less than that observed, with the former due in part to simulated ENSO in the models being generally weaker than observed, and the latter likely to be at least partially due to the uncertainty in the estimates of past radiative forcing; 3) an El Niño-like pattern in the mean SST response with greater surface warming in the eastern equatorial Pacific than the western equatorial Pacific is found by a number of models in global warming climate change experiments, but other models have a more spatially uniform or even a La Niña-like, response; 4) flux adjustment, by definition, improves the simulation of mean present-day climate over oceans, does not guarantee a drift-free climate, but can produce a stable base state in some models to enable very long term (1000 yr and longer) integrations-in these models it does not appear to have a major effect on model processes or model responses to increasing CO2; and 5) recent

  8. Coupled intertwiner dynamics: A toy model for coupling matter to spin foam models

    NASA Astrophysics Data System (ADS)

    Steinhaus, Sebastian

    2015-09-01

    The universal coupling of matter and gravity is one of the most important features of general relativity. In quantum gravity, in particular spin foams, matter couplings have been defined in the past, yet the mutual dynamics, in particular if matter and gravity are strongly coupled, are hardly explored, which is related to the definition of both matter and gravitational degrees of freedom on the discretization. However, extracting these mutual dynamics is crucial in testing the viability of the spin foam approach and also establishing connections to other discrete approaches such as lattice gauge theories. Therefore, we introduce a simple two-dimensional toy model for Yang-Mills coupled to spin foams, namely an Ising model coupled to so-called intertwiner models defined for SU (2 )k. The two systems are coupled by choosing the Ising coupling constant to depend on spin labels of the background, as these are interpreted as the edge lengths of the discretization. We coarse grain this toy model via tensor network renormalization and uncover an interesting dynamics: the Ising phase transition temperature turns out to be sensitive to the background configurations and conversely, the Ising model can induce phase transitions in the background. Moreover, we observe a strong coupling of both systems if close to both phase transitions.

  9. Analytical model of internally coupled ears.

    PubMed

    Vossen, Christine; Christensen-Dalsgaard, Jakob; van Hemmen, J Leo

    2010-08-01

    Lizards and many birds possess a specialized hearing mechanism: internally coupled ears where the tympanic membranes connect through a large mouth cavity so that the vibrations of the tympanic membranes influence each other. This coupling enhances the phase differences and creates amplitude differences in the tympanic membrane vibrations. Both cues show strong directionality. The work presented herein sets out the derivation of a three dimensional analytical model of internally coupled ears that allows for calculation of a complete vibration profile of the membranes. The analytical model additionally provides the opportunity to incorporate the effect of the asymmetrically attached columella, which leads to the activation of higher membrane vibration modes. Incorporating this effect, the analytical model can explain measurements taken from the tympanic membrane of a living lizard, for example, data demonstrating an asymmetrical spatial pattern of membrane vibration. As the analytical calculations show, the internally coupled ears increase the directional response, appearing in large directional internal amplitude differences (iAD) and in large internal time differences (iTD). Numerical simulations of the eigenfunctions in an exemplary, realistically reconstructed mouth cavity further estimate the effects of its complex geometry. PMID:20707461

  10. Modeling partially coupled objects with smooth particle hydrodynamics

    SciTech Connect

    Wingate, C.A.

    1996-10-01

    A very simple phenomenological model is presented to model objects that are partially coupled (i.e. welded or bonded) where usually the coupled interface is weaker than the bulk material. The model works by letting objects fully interact in compression and having the objects only partially interact in tension. A disconnect factor is provided to adjust the tensile interaction to simulate coupling strengths. Three cases of an example impact calculation are shown-no coupling, full coupling and partial coupling.

  11. PREFACE: 5th International Workshop on Top Quark Physics (TOP2012)

    NASA Astrophysics Data System (ADS)

    Salamanna, G.; Boisvert, V.; Cerrito, L.; Khan, A.; Moretti, S.; Owen, M.; Schwanenberger, C.

    2013-07-01

    The 5th International Workshop on Top Quark Physics (TOP 2012) took place in Winchester, UK, from the 16-21 September. It gathered students as well as people active in the top quark sector and provided a framework to highlight the newest results and matters related to top quark physics. Discovered in 1995, the top quark is the sixth and heaviest of all quarks, and it is the only one with a lifetime short enough to be observed 'naked'. This makes it an important testing ground in the search for new physics. In fact, the fact of its mass being so much larger than the other quarks, hints at its special role in the Higgs mechanism. For the same reason, in many models of New Physics, new heavy resonances are expected to couple mostly with top quarks. Even if no new particles are observed, the direct correlation between its angular momentum and that of its detectable decay products allows us to probe indirectly New Physics in action when top quarks are created. In this edition of the TOP conference series, for the first time, the agenda was equally balanced between 'traditional' measurements and the now vast number of searches for physics BSM in the top quark sector, thanks mostly to the amount of data collected at the LHC in its Run I. New results were presented by both the Tevatron and the LHC collaborations: improved ttbar and single top cross-section measurements, refined techniques to measure the top quark mass and a large number of results on properties such as spin correlation and W boson polarization in top quark decays were shown. More technical discussions on the experimental issues, both from the detector and the simulation side also took place, drawing together experimentalists and theorists. Reviews of the latest results on ttbar asymmetry both from CDF and D0 and from ATLAS and CMS were shown, and theorists active in the field made some interesting points on this hot topic. Additionally, results on the search for fourth generation fermions and new

  12. Modeling coupled avulsion and earthquake timescale dynamics

    NASA Astrophysics Data System (ADS)

    Reitz, M. D.; Steckler, M. S.; Paola, C.; Seeber, L.

    2014-12-01

    River avulsions and earthquakes can be hazardous events, and many researchers work to better understand and predict their timescales. Improvements in the understanding of the intrinsic processes of deposition and strain accumulation that lead to these events have resulted in better constraints on the timescales of each process individually. There are however several mechanisms by which these two systems may plausibly become linked. River deposition and avulsion can affect the stress on underlying faults through differential loading by sediment or water. Conversely, earthquakes can affect river avulsion patterns through altering the topography. These interactions may alter the event recurrence timescales, but this dynamic has not yet been explored. We present results of a simple numerical model, in which two systems have intrinsic rates of approach to failure thresholds, but the state of one system contributes to the other's approach to failure through coupling functions. The model is first explored for the simplest case of two linear approaches to failure, and linearly proportional coupling terms. Intriguing coupling dynamics emerge: the system settles into cycles of repeating earthquake and avulsion timescales, which are approached at an exponential decay rate that depends on the coupling terms. The ratio of the number of events of each type and the timescale values also depend on the coupling coefficients and the threshold values. We then adapt the model to a more complex and realistic scenario, in which a river avulses between either side of a fault, with parameters corresponding to the Brahmaputra River / Dauki fault system in Bangladesh. Here the tectonic activity alters the topography by gradually subsiding during the interseismic time, and abruptly increasing during an earthquake. The river strengthens the fault by sediment loading when in one path, and weakens it when in the other. We show this coupling can significantly affect earthquake and avulsion

  13. Coupled wave model for large magnet coils

    NASA Technical Reports Server (NTRS)

    Gabriel, G. J.

    1980-01-01

    A wave coupled model based on field theory is evolved for analysis of fast electromagnetic transients on superconducting coils. It is expected to play a useful role in the design of protection methods against damage due to high voltages or any adverse effects that might arise from unintentional transients. The significant parameters of the coil are identified to be the turn to turn wave coupling coefficients and the travel time of an electromagnetic disturbance around a single turn. Unlike circuit theoretic inductor, the coil response evolves in discrete steps having durations equal to this travel time. It is during such intervals that high voltages are likely to occur. The model also bridges the gap between the low and high ends of the frequency spectrum.

  14. Towards Better Coupling of Hydrological Simulation Models

    NASA Astrophysics Data System (ADS)

    Penton, D.; Stenson, M.; Leighton, B.; Bridgart, R.

    2012-12-01

    Standards for model interoperability and scientific workflow software provide techniques and tools for coupling hydrological simulation models. However, model builders are yet to realize the benefits of these and continue to write ad hoc implementations and scripts. Three case studies demonstrate different approaches to coupling models, the first using tight interfaces (OpenMI), the second using a scientific workflow system (Trident) and the third using a tailored execution engine (Delft Flood Early Warning System - Delft-FEWS). No approach was objectively better than any other approach. The foremost standard for coupling hydrological models is the Open Modeling Interface (OpenMI), which defines interfaces for models to interact. An implementation of the OpenMI standard involves defining interchange terms and writing a .NET/Java wrapper around the model. An execution wrapper such as OatC.GUI or Pipistrelle executes the models. The team built two OpenMI implementations for eWater Source river system models. Once built, it was easy to swap river system models. The team encountered technical challenges with versions of the .Net framework (3.5 calling 4.0) and with the performance of the execution wrappers when running daily simulations. By design, the OpenMI interfaces are general, leaving significant decisions around the semantics of the interfaces to the implementer. Increasingly, scientific workflow tools such as Kepler, Taverna and Trident are able to replace custom scripts. These tools aim to improve the provenance and reproducibility of processing tasks. In particular, Taverna and the myExperiment website have had success making many bioinformatics workflows reusable and sharable. The team constructed Trident activities for hydrological software including IQQM, REALM and eWater Source. They built an activity generator for model builders to build activities for particular river systems. The models were linked at a simulation level, without any daily time

  15. Nonlinear Walecka models and point-coupling relativistic models

    SciTech Connect

    Lourenco, O.; Amaral, R. L. P. G.; Dutra, M.; Delfino, A.

    2009-10-15

    We study hadronic nonlinear point-coupling (NLPC) models which reproduce numerically the binding energy, the incompressibility, and the nucleon effective mass at the nuclear matter saturation obtained by different nonlinear Walecka (NLW) models. We have investigated their behaviors as functions of the nuclear matter density to observe how they deviate from known NLW models. In our study we present a meson-exchange modified nonlinear Walecka model (MNLW) which exactly underlies a nonlinear point-coupling model (NLPC) presenting third- and fourth-order scalar density self-couplings. A discussion about naive dimensional analysis (NDA) and naturalness is also provided for a large class of NLW and NLPC models. At finite temperature, critical and flash parameters of both approaches are presented.

  16. Four mass coupled oscillator guitar model.

    PubMed

    Popp, John E

    2012-01-01

    Coupled oscillator models have been used for the low frequency response (50 to 250 Hz) of a guitar. These 2 and 3 mass models correctly predict measured resonance frequency relationships under various laboratory boundary conditions, but did not always represent the true state of a guitar in the players' hands. The model presented has improved these models in three ways, (1) a fourth oscillator includes the guitar body, (2) plate stiffnesses and other fundamental parameters were measured directly and effective areas and masses used to calculate the responses, including resonances and phases, directly, and (3) one of the three resultant resonances varies with neck and side mass and can also be modeled as a bar mode of the neck and body. The calculated and measured resonances and phases agree reasonably well. PMID:22280705

  17. Work Values of 5th, 8th, and 11th Grade Students

    ERIC Educational Resources Information Center

    Hales, Loyde W.; Fenner, Bradford

    1972-01-01

    Self Realization, Job Security, Money, and Altruism were found to be the most important work values, with 5th and 8th grade students differing from 11th grade students on Altruism and Self Realization. (Author)

  18. 25. April 5th one month's work. View looking north. Storehouse ...

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

    25. April 5th one month's work. View looking north. Storehouse #1 under construction, storehouse #2 site work in progress toward foreground. - U.S. Navy Fleet Supply Base, Storehouse No. 1, 830 Third Avenue, Brooklyn, Kings County, NY

  19. 17. 4th floor roof, view south, 4th and 5th floor ...

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

    17. 4th floor roof, view south, 4th and 5th floor setback to left and atrium structure to right - Sheffield Farms Milk Plant, 1075 Webster Avenue (southwest corner of 166th Street), Bronx, Bronx County, NY

  20. 6. 5TH FLOOR, VIEW NORTH OF KETTLE SOAP STORAGE TANKS ...

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

    6. 5TH FLOOR, VIEW NORTH OF KETTLE SOAP STORAGE TANKS (RIGHT) AND WEIGH HOPPERS OVER SITES OF REMOVED AMALGAMATORS (LEFT) - Colgate & Company Jersey City Plant, Building No. B-14, 54-58 Grand Street, Jersey City, Hudson County, NJ

  1. Coupling a terrestrial biogeochemical model to the common land model

    SciTech Connect

    Shi, Xiaoying; Mao, Jiafu; Wang, Yingping; Dai, Yongjiu; Tang, Xuli

    2011-01-01

    A terrestrial biogeochemical model (CASACNP) was coupled to a land surface model (the Common Land Model, CoLM) to simulate the dynamics of carbon substrate in soil and its limitation on soil respiration. The combined model, CoLM-CASACNP, was able to predict long-term carbon sources and sinks that CoLM alone could not. The coupled model was tested using measurements of belowground respiration and surface fluxes from two forest ecosystems. The combined model simulated reasonably well the diurnal and seasonal variations of net ecosystem carbon exchange, as well as seasonal variation in the soil respiration rate of both the forest sites chosen for this study. However, the agreement between model simulations and actual measurements was poorer under dry conditions. The model should be tested against more measurements before being applied globally to investigate the feedbacks between the carbon cycle and climate change.

  2. Session on validation of coupled models

    NASA Technical Reports Server (NTRS)

    Kuo, Bill

    1993-01-01

    The session on validation of coupled models is reviewed. The current use of a mesoscale model with a grid size of 20-km during STORM-FEST in 1992 has proven to be extremely valuable. The availability of forecast products at a much higher temporal and spatial resolution was very helpful for mesoscale forecasting, mission planning, and the guidance of research aircraft. Recent numerical simulation of ocean cyclones and mesoscsle convective systems using nonhydrostatic cloud/mesoscale models with a grid size as small as 2-km have demonstrated the potential of these models for predicting mesoscale convective systems, squall lines, hurricane rainbands, mesoscale gravity waves, and mesoscale frontal structures embedded within an extratropical cyclone. Although mesoscale/cloud scale models have demonstrated strong potential for use in operational forecasting, very limited quantitative evaluation (and verification) of these models were performed. As a result, the accuracy, the systematic biases, and the useful forecasts limits were not properly defined for these models. Also, no serious attempts were made to use these models for operational prediction of mesoscale convective systems.

  3. Numerical Fluid Dynamics Symposium, 5th, Tokyo, Japan, Dec. 19-21, 1991, Proceedings

    NASA Astrophysics Data System (ADS)

    1991-07-01

    Various papers on numerical fluid dynamics are presented. Individual topics discussed include: numerical analysis (NA) of shock structure problems, CFD development and a future high-speed computer, simulating vortex motion by 3D method, application of CFD to turbomachine design, numerical simulation (NS) of converging shock waves, NS of unsteady 3D shock wave phenomenon, 5th-order accurate compact upwind scheme, development of a multidimensional upwind scheme, fortified solution algorithm, large-eddy simulation of a bound jet, construction of collision model of diatomic molecules, VSL analysis of nonequilibrium flows around a hypersonic body, NA of chemically nonequilibrium flow, topological transition of flow past some axisymmetric bodies, modeling of scalar transport in free turbulence, a contribution to general application of the vortex method. Also addressed are: vortex simulation of artificial control of mixing layers, 3D motion of vortex filaments, Navier-Stokes simulation of 2D mixing layer, active control of vortex shedding frequency by a jet, direct NS of homogeneous turbulent sheer flow, NA of fuel spray jet by Eulerian method, NS of ignition using a premixed pulsed jet, NS of a scram jet combustor flow, numerical simulation of supersonic flow CO chemical laser, adaptive grid generation using optimal control theory, NS of characteristics of the Stalker tube, imcompressible flow solver using velocity vector and a new variable, unsteady analysis of helicopter rotor.

  4. Determination of Motivation of 5th Grade Students Living in Rural and Urban Environments towards Science Learning and Their Attitudes towards Science-Technology Course

    ERIC Educational Resources Information Center

    Kenar, Ismail; Köse, Mücahit; Demir, Halil Ibrahim

    2016-01-01

    In this research, determination of motivation of 5th grade students living in rural and urban environments towards science learning and their attitudes towards science-technology course is aimed. This research is conducted based on descriptive survey model. Samples are selected through teleological model in accordance with the aim of this…

  5. Multiphysics and Multiscale Model Coupling Using Gerris

    NASA Astrophysics Data System (ADS)

    Keen, T. R.; Dykes, J. D.; Campbell, T. J.

    2012-12-01

    This work is implementing oceanographic processes encompassing multiple physics and scales using the Gerris Flow Solver (GFS) in order to examine their interdependence and sensitivity to changes in the physical environment. The processes include steady flow due to tides and the wind, phase-averaged wave-forced flow and oscillatory currents, and sediment transport. The 2D steady flow is calculated by the Ocean module contained within GFS. This model solves the Navier-Stokes (N-S) equations using the finite volume method. The model domain is represented by quad-tree adaptive mesh refinement (AMR). A stationary wave field is computed for a specified wave spectrum is uniformly distributed over the domain as a tracer with local wind input parameterized as a source, and dissipation by friction and breaking as a sink. Alongshore flow is included by a radiation stress term; this current is added to the steady flow component from tides and wind. Wave-current interaction is parameterized using a bottom boundary layer model. Sediment transport as suspended and bed load is implemented using tracers that are transported via the advection equations. A bed-conservation equation is implemented to allow changes in seafloor elevation to be used in adjusting the AMR refinement. These processes are being coupled using programming methods that are inherent to GFS and that do not require modification or recompiling of the code. These techniques include passive tracers, C functions that operate as plug-ins, and user-defined C-type macros included with GFS. Our results suggest that the AMR model coupling method is useful for problems where the dynamics are governed by several processes. This study is examining the relative influence of the steady currents, wave field, and sedimentation. Hydrodynamic and sedimentation interaction in nearshore environments is being studied for an idealized beach and for the Sandy Duck storm of Oct. 1998. The potential behavior of muddy sediments on the

  6. Coupled map lattice model of jet breakup

    SciTech Connect

    Minich, R W; Schwartz, A J; Baker, E L

    2001-01-25

    An alternative approach is described to evaluate the statistical nature of the breakup of shaped charge liners. Experimental data from ductile and brittle copper jets are analyzed in terms of velocity gradient, deviation of {Delta}V from linearity, R/S analysis, and the Hurst exponent within the coupled map lattice model. One-dimensional simulations containing 600 zones of equal mass and using distinctly different force-displacement curves are generated to simulate ductile and brittle behavior. A particle separates from the stretching jet when an element of material reaches the failure criterion. A simple model of a stretching rod using brittle, semi-brittle, and ductile force-displacement curves is in agreement with the experimental results for the Hurst exponent and the phase portraits and indicates that breakup is a correlated phenomenon.

  7. Generalized hydrodynamics model for strongly coupled plasmas

    NASA Astrophysics Data System (ADS)

    Diaw, A.; Murillo, M. S.

    2015-07-01

    Beginning with the exact equations of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, we obtain the density, momentum, and stress tensor-moment equations. We close the moment equations with two closures, one that guarantees an equilibrium state given by density-functional theory and another that includes collisions in the relaxation of the stress tensor. The introduction of a density functional-theory closure ensures self-consistency in the equation-of-state properties of the plasma (ideal and excess pressure, electric fields, and correlations). The resulting generalized hydrodynamics thus includes all impacts of Coulomb coupling, viscous damping, and the high-frequency (viscoelastic) response. We compare our results with those of several known models, including generalized hydrodynamic theory and models obtained using the Singwi-Tosi-Land-Sjolander approximation and the quasilocalized charge approximation. We find that the viscoelastic response, including both the high-frequency elastic generalization and viscous wave damping, is important for correctly describing ion-acoustic waves. We illustrate this result by considering three very different systems: ultracold plasmas, dusty plasmas, and dense plasmas. The new model is validated by comparing its results with those of the current autocorrelation function obtained from molecular-dynamics simulations of Yukawa plasmas, and the agreement is excellent. Generalizations of this model to mixtures and quantum systems should be straightforward.

  8. Reflecting on the 5th World Environmental Education Congress, Montreal, 2009

    ERIC Educational Resources Information Center

    Jickling, Bob

    2010-01-01

    This article traces the development of the World Environmental Congress movement and its establishment as an important international forum. Reflecting on the 5th Congress, it notes the particular contribution of the Congress theme, "Our Common Home". Finally, it considers environmental education's place alongside other parallel transformative…

  9. 75 FR 63478 - 5th Annual PHEMCE Stakeholders Workshop and BARDA Industry Day

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ...The Department of Health and Human Services (HHS) is pleased to announce the upcoming 5th Annual Public Health Emergency Medical Countermeasures Enterprise (PHEMCE) Stakeholders Workshop and BARDA Industry Day to be held January 10-12, 2011 at the Walter E. Washington Convention Center in Washington, DC. This annual PHEMCE event will bring together private- and public-sector stakeholders......

  10. A Network Sets Things in Motion: TEDD Celebrates its 5(th) Anniversary.

    PubMed

    2015-01-01

    At the Annual Meeting at ZHAW Waedenswil on 22 October 2015, the TEDD-Network (Tissue Engineering for Drug Development and Substance Testing) celebrated its 5(th) anniversary. Since its foundation, TEDD has become an internationally renowned competence centre and includes currently 91 members from academia and industry. They cover the entire development and value chain. PMID:26671055

  11. Urban 5th Graders Conceptions during a Place-Based Inquiry Unit on Watersheds

    ERIC Educational Resources Information Center

    Endreny, Anna Henderson

    2010-01-01

    This study aimed to determine how 33 urban 5th grade students' science conceptions changed during a place-based inquiry unit on watersheds. Research on watershed and place-based education was used as a framework to guide the teaching of the unit as well as the research study. A teacher-researcher designed the curriculum, taught the unit and…

  12. The 5th World Environmental Education Congress, 2009: A Research Project

    ERIC Educational Resources Information Center

    Jickling, Bob; Sauve, Lucie; Briere, Laurence; Niblett, Blair; Root, Emily

    2010-01-01

    This paper contextualizes the 5th World Environmental Education Congress, discusses the theoretical underpinnings of the Congress theme "Earth Our Common Home," and relates this theorizing to the research project that was woven through the Congress. We provide a rationale for engaging in this research project, as an invitation for Congress…

  13. 10. Interior view, working house, scale floor (5th level). View ...

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

    10. Interior view, working house, scale floor (5th level). View facing across floor toward no. 2 scale and garner. Tile structure at left center is weighmaster's shack; view facing east. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

  14. An Investigation of Science and Technology Teachers' Views on the 5th Grade Science Course

    ERIC Educational Resources Information Center

    Dasdemir, Ikramettin

    2014-01-01

    This study was conducted to explore the science and technology teachers' views on the implementation of 5th grade science course. Open-ended questions were used as a data collection tool. The study sample consisted of 28 science and technology teachers working in Erzurum in 2012-2013 education year. The data gathered were analysed via content…

  15. Vocabulary and Syntactic Knowledge Factors in 5th Grade Students' Reading Comprehension

    ERIC Educational Resources Information Center

    Mokhtari, Kouider; Niederhauser, Dale S.

    2013-01-01

    In this study, we examined 5th grade students' levels of vocabulary knowledge and syntactic awareness relative to their reading comprehension performance. The aim was to explore the contributions of vocabulary and syntactic awareness as potential sources of reading comprehension difficulty for these readers. Overall, we found that both vocabulary…

  16. 78 FR 53454 - Filing Dates for the Louisiana Special Elections in the 5th Congressional District

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ELECTION COMMISSION Filing Dates for the Louisiana Special Elections in the 5th Congressional District AGENCY: Federal Election Commission. ACTION: Notice of filing dates for special election. SUMMARY: Louisiana has...

  17. The 5th edition of the Roma-BZCAT. A short presentation

    NASA Astrophysics Data System (ADS)

    Massaro, E.; Maselli, A.; Leto, C.; Marchegiani, P.; Perri, M.; Giommi, P.; Piranomonte, S.

    2015-05-01

    The 5th edition of the Roma-BZCAT Multifrequency Catalogue of Blazars is available in a printed version and online at the ASDC website (http://www.asdc.asi.it/bzcat); it is also in the NED database. It presents several relevant changes with respect to the past editions which are briefly described in this paper.

  18. Socially, Developmentally, and Academically Appropriate Prevention Curriculum for 5th Graders

    ERIC Educational Resources Information Center

    Harthun, Mary L.; Dustman, Patricia A.; Reeves, Leslie J.; Marsiglia, Flavio F.; Hecht, Michael L.

    2009-01-01

    This paper reports on a process in which program designers, classroom teachers, and students worked together to adapt the 7th grade "keepin' it REAL" prevention curriculum to a developmentally, socially, and academically appropriate curriculum for 5th graders. A Community-Based Participatory Research methodology (CBPR), combined with a 9-step…

  19. Oral Persuasion: A Saleable Work Skill. Occupation Simulation Packet. Grades 5th-6th.

    ERIC Educational Resources Information Center

    Lee, Dennis W.

    This teacher's guide contains simulated work experiences for 5th and 6th grade students using the isolated skill concept - oral persuasion. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Two pre-skill activities are suggested, such as…

  20. 9. 5TH FLOOR, INTERIOR DETAIL TO EAST OF SOAP BIN ...

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

    9. 5TH FLOOR, INTERIOR DETAIL TO EAST OF SOAP BIN No. 4: UPPER SCREWS MOVED SOAP CHIPS HORIZONTALLY FROM BIN TO BIN; LOWER LEFT-AND RIGHT-HAND SCREWS MOVED CHIPS TO CHUTE LEADING TO 3RD FLOOR SOAP MILLS - Colgate & Company Jersey City Plant, Building No. B-14, 54-58 Grand Street, Jersey City, Hudson County, NJ

  1. How Arizona Compares: Real Numbers and Hot Topics. Policy Choices. 5th Edition

    ERIC Educational Resources Information Center

    Morrison Institute for Public Policy, 2005

    2005-01-01

    Morrison Institute for Public Policy is pleased to present "How Arizona Compares: Real Numbers and Hot Topics," the 5th edition of Arizona "Policy Choices." The Arizona "Policy Choices" volumes seek to do more than report. They are designed to assist decision making, stimulate debate, and serve as references. Arizona "Policy Choices" volumes have…

  2. Successfully Promoting 21st Century Online Research Skills: Interventions in 5th-Grade Classrooms

    ERIC Educational Resources Information Center

    Kingsley, Tara L.; Cassady, Jerrell C.; Tancock, Susan M.

    2015-01-01

    This quantitative study was developed to explore the ability to impact elementary student 21st Century online research skills with a planned classroom intervention curriculum. The repeated measures quasi-experimental study randomly assigned all 5th grade classes in a Midwestern, suburban school (n = 418) to a 12-week intervention or control…

  3. Effects of temperature and modified atmospheres on diapausing 5th instar codling moth metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diapausing 5th instars of codling moth, Cydia pomonella, are serious quarantine pests of in-shell walnuts. Previous research indicates that heat treatments in combination with high concentrations of carbon dioxide and low concentrations of oxygen may be effective for controlling this pest in walnuts...

  4. Extended source model for diffusive coupling.

    PubMed

    González-Ochoa, Héctor O; Flores-Moreno, Roberto; Reyes, Luz M; Femat, Ricardo

    2016-01-01

    Motivated by the prevailing approach to diffusion coupling phenomena which considers point-like diffusing sources, we derived an analogous expression for the concentration rate of change of diffusively coupled extended containers. The proposed equation, together with expressions based on solutions to the diffusion equation, is intended to be applied to the numerical solution of systems exclusively composed of ordinary differential equations, however is able to account for effects due the finite size of the coupled sources. PMID:26802012

  5. Lithosphere-Atmosphere-Ionosphere coupling model

    NASA Astrophysics Data System (ADS)

    Kachakhidze, M. K., III

    2015-12-01

    The present work offers interpretation of a mechanism of formation of hypothetic ideal electromagnetic contour, creation of which is envisaged in incoming earthquake focal zone. Model of generation of EM emissions detected before earthquake is based on physical analogues of distributed and conservative systems and focal zones. According to the model the process of earthquake preparation from the moment of appearance of cracks in the system, including completion of series of foreshocks, earthquake and aftershocks, are entirely explained by oscillating systems.According to the authors of the work electromagnetic emissions in radio diapason is more universal and reliable than other anomalous variations of various geophysical phenomena in earthquake preparation period; Besides, VLF/LF electromagnetic emissions might be declared as the main precursor of earthquake because it might turn out very useful with the view of prediction of large (M5) inland earthquakes and to govern processes going on in lithosphere-atmosphere-ionosphere coupling (LAIC) system. Based on this model, in case of electromagnetic emissions spectrum monitoring in the period that precedes earthquake it is possible to determine, with certain accuracy, the time, location and magnitude of an incoming earthquake simultaneously.The present item considers possible physical mechanisms of the geophysical phenomena, which may accompany earthquake preparation process and expose themselves several months, weeks or days prior to earthquakes. Such as: Changing of intensity of electro-telluric current in focal area; Perturbations of geomagnetic field in forms of irregular pulsations or regular short-period pulsations; Perturbations of atmospheric electric field; Irregular changing of characteristic parameters of the lower ionosphere (plasma frequency, electron concentration, height of D layer, etc.); Irregular perturbations reaching the upper ionosphere, namely F2-layer, for 2-3 days before the earthquake

  6. Coupling approaches used in atmospheric entry models

    NASA Astrophysics Data System (ADS)

    Gritsevich, M. I.

    2012-09-01

    While a planet orbits the Sun, it is subject to impact by smaller objects, ranging from tiny dust particles and space debris to much larger asteroids and comets. Such collisions have taken place frequently over geological time and played an important role in the evolution of planets and the development of life on the Earth. Though the search for near-Earth objects addresses one of the main points of the Asteroid and Comet Hazard, one should not underestimate the useful information to be gleaned from smaller atmospheric encounters, known as meteors or fireballs. Not only do these events help determine the linkages between meteorites and their parent bodies; due to their relative regularity they provide a good statistical basis for analysis. For successful cases with found meteorites, the detailed atmospheric path record is an excellent tool to test and improve existing entry models assuring the robustness of their implementation. There are many more important scientific questions meteoroids help us to answer, among them: Where do these objects come from, what are their origins, physical properties and chemical composition? What are the shapes and bulk densities of the space objects which fully ablate in an atmosphere and do not reach the planetary surface? Which values are directly measured and which are initially assumed as input to various models? How to couple both fragmentation and ablation effects in the model, taking real size distribution of fragments into account? How to specify and speed up the recovery of a recently fallen meteorites, not letting weathering to affect samples too much? How big is the pre-atmospheric projectile to terminal body ratio in terms of their mass/volume? Which exact parameters beside initial mass define this ratio? More generally, how entering object affects Earth's atmosphere and (if applicable) Earth's surface? How to predict these impact consequences based on atmospheric trajectory data? How to describe atmospheric entry

  7. Madden-Julian Variability in Coupled Models

    SciTech Connect

    Sperber, K R; Gualdi, S; Li, W; Slingo, J M

    2001-12-12

    The Madden-Julian Oscillation (MJO) is a dominant mode of tropical variability (Madden and Julian 1971, 1972). It is manifested on a timescale of {approx}30-70 days through large-scale circulation anomalies which occur in conjunction with eastward propagating convective anomalies over the eastern hemisphere. Recent evidence has suggested that an interactive ocean may be important for the simulation of the Madden-Julian Oscillation (Flatau et al. 1997, Sperber et al. 1997, Waliser et al. 1999, Inness et al. 2002). As part of an initiative to the CLIVAR Working Group on Coupled Modeling, we examine ocean-atmosphere GCMs to ascertain the degree to which they can represent the 4-dimensional space-time structure of the MJO. The eastward propagation of convection is also examined with respect to the surface fluxes and SST, and we compare and contrast the behavior over the Indian Ocean and the western Pacific. Importantly, the results are interpreted with respect to systematic error of the mean state.

  8. Coupling Climate Models and Forward-Looking Economic Models

    NASA Astrophysics Data System (ADS)

    Judd, K.; Brock, W. A.

    2010-12-01

    Authors: Dr. Kenneth L. Judd, Hoover Institution, and Prof. William A. Brock, University of Wisconsin Current climate models range from General Circulation Models (GCM’s) with millions of degrees of freedom to models with few degrees of freedom. Simple Energy Balance Climate Models (EBCM’s) help us understand the dynamics of GCM’s. The same is true in economics with Computable General Equilibrium Models (CGE’s) where some models are infinite-dimensional multidimensional differential equations but some are simple models. Nordhaus (2007, 2010) couples a simple EBCM with a simple economic model. One- and two- dimensional ECBM’s do better at approximating damages across the globe and positive and negative feedbacks from anthroprogenic forcing (North etal. (1981), Wu and North (2007)). A proper coupling of climate and economic systems is crucial for arriving at effective policies. Brock and Xepapadeas (2010) have used Fourier/Legendre based expansions to study the shape of socially optimal carbon taxes over time at the planetary level in the face of damages caused by polar ice cap melt (as discussed by Oppenheimer, 2005) but in only a “one dimensional” EBCM. Economists have used orthogonal polynomial expansions to solve dynamic, forward-looking economic models (Judd, 1992, 1998). This presentation will couple EBCM climate models with basic forward-looking economic models, and examine the effectiveness and scaling properties of alternative solution methods. We will use a two dimensional EBCM model on the sphere (Wu and North, 2007) and a multicountry, multisector regional model of the economic system. Our aim will be to gain insights into intertemporal shape of the optimal carbon tax schedule, and its impact on global food production, as modeled by Golub and Hertel (2009). We will initially have limited computing resources and will need to focus on highly aggregated models. However, this will be more complex than existing models with forward

  9. FOREWORD: 5th International Workshop on New Computational Methods for Inverse Problems

    NASA Astrophysics Data System (ADS)

    Vourc'h, Eric; Rodet, Thomas

    2015-11-01

    This volume of Journal of Physics: Conference Series is dedicated to the scientific research presented during the 5th International Workshop on New Computational Methods for Inverse Problems, NCMIP 2015 (http://complement.farman.ens-cachan.fr/NCMIP_2015.html). This workshop took place at Ecole Normale Supérieure de Cachan, on May 29, 2015. The prior editions of NCMIP also took place in Cachan, France, firstly within the scope of ValueTools Conference, in May 2011, and secondly at the initiative of Institut Farman, in May 2012, May 2013 and May 2014. The New Computational Methods for Inverse Problems (NCMIP) workshop focused on recent advances in the resolution of inverse problems. Indeed, inverse problems appear in numerous scientific areas such as geophysics, biological and medical imaging, material and structure characterization, electrical, mechanical and civil engineering, and finances. The resolution of inverse problems consists of estimating the parameters of the observed system or structure from data collected by an instrumental sensing or imaging device. Its success firstly requires the collection of relevant observation data. It also requires accurate models describing the physical interactions between the instrumental device and the observed system, as well as the intrinsic properties of the solution itself. Finally, it requires the design of robust, accurate and efficient inversion algorithms. Advanced sensor arrays and imaging devices provide high rate and high volume data; in this context, the efficient resolution of the inverse problem requires the joint development of new models and inversion methods, taking computational and implementation aspects into account. During this one-day workshop, researchers had the opportunity to bring to light and share new techniques and results in the field of inverse problems. The topics of the workshop were: algorithms and computational aspects of inversion, Bayesian estimation, Kernel methods, learning methods

  10. Strong coupling theory for interacting lattice models

    NASA Astrophysics Data System (ADS)

    Stanescu, Tudor D.; Kotliar, Gabriel

    2004-11-01

    We develop a strong coupling approach for a general lattice problem. We argue that this strong coupling perspective represents the natural framework for a generalization of the dynamical mean field theory (DMFT). The main result of this analysis is twofold: (1) It provides the tools for a unified treatment of any nonlocal contribution to the Hamiltonian. Within our scheme, nonlocal terms such as hopping terms, spin-spin interactions, or nonlocal Coulomb interactions are treated on equal footing. (2) By performing a detailed strong-coupling analysis of a generalized lattice problem, we establish the basis for possible clean and systematic extensions beyond DMFT. To this end, we study the problem using three different perspectives. First, we develop a generalized expansion around the atomic limit in terms of the coupling constants for the nonlocal contributions to the Hamiltonian. By analyzing the diagrammatics associated with this expansion, we establish the equations for a generalized dynamical mean-field theory. Second, we formulate the theory in terms of a generalized strong coupling version of the Baym-Kadanoff functional. Third, following Pairault, Sénéchal, and Tremblay [Phys. Rev. Lett. 80, 5389 (1998)], we present our scheme in the language of a perturbation theory for canonical fermionic and bosonic fields and we establish the interpretation of various strong coupling quantities within a standard perturbative picture.

  11. Modeling of coupled geochemical and transport processes: An overview

    SciTech Connect

    Carnahan, C.L.

    1989-10-01

    Early coupled models associated with fluid flow and solute transport have been limited by assumed conditions of constant temperature, fully saturated fluid flow, and constant pore fluid velocity. Developments including coupling of chemical reactions to variable fields of temperature and fluid flow have generated new requirements for experimental data. As the capabilities of coupled models expand, needs are created for experimental data to be used for both input and validation. 25 refs.

  12. VizieR Online Data Catalog: The Roma BZCAT - 5th edition (Massaro+, 2015)

    NASA Astrophysics Data System (ADS)

    Massaro, E.; Giommi, P.; Leto, C.; Marchegiani, P.; Maselli, A.; Perri, M.; Piranomonte, S.; Sclavi, S.

    2016-02-01

    In the 5th Edition we use similar denomination of blazars adopted in the previous editions. Each blazar is identified by a code, with 5BZ for all blazars, a fourth letter that specifies the type (B, G, Q or U), followed by the truncated equatorial coordinates (J2000). We introduced the edition number before the letters BZ to avoid possible confusion due to the fact that several sources changed their old names because of the new adopted classification. The codes are defined in the "Note (G1)" below. The 5th edition contains 1151 BZB sources, 92 of which are reported as candidates because we could not find their optical spectra in the literature, 1909 BZQ sources, 274 BZG sources and 227 BZU objects (1 data file).

  13. An 8 x 10 to the 5th bit bubble memory cell for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Becker, F. J.; Murray, G. W.; Bohning, O. D.; Stermer, R. L.

    1980-01-01

    A multiple chip magnetic bubble memory cell design developed for NASA embodies the low power, low weight, environmental tolerance and reliability necessary for successful operation in spacecraft launch and mission environments. Packaging of multiple chips in a common magnetic bias, drive coil assembly reduces weight and volume overhead per chip and also reduces the number of coil drive components required. This 8 x 10 to the 5th bit cell is conduction cooled and provides a metal and ceramic sealed hermetic chip environment.

  14. Instantaneous frequency measurement by in-fiber 0.5th order fractional differentiation

    NASA Astrophysics Data System (ADS)

    Poveda-Wong, L.; Carrascosa, A.; Cuadrado-Laborde, C.; Cruz, J. L.; Díez, A.; Andrés, M. V.

    2016-07-01

    We experimentally demonstrate the possibility to retrieve the instantaneous frequency profile of a given temporal light pulse by in-fiber fractional order differentiation of 0.5th-order. The signal's temporal instantaneous frequency profile is obtained by simple dividing two temporal intensity profiles, namely the intensities of the input and output pulses of a spectrally-shifted fractional order differentiation. The results are supported by the experimental measurement of the instantaneous frequency profile of a mode-locked laser.

  15. Proceedings of the 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED-2004)

    NASA Astrophysics Data System (ADS)

    Suh, Eun-Kyung; Yoon, Euijoon; Lee, Hyung Jae

    2004-09-01

    The 5th International Symposium on Blue Laser and Light Emitting Diodes (ISBLLED-2004) was held in Gyeongju, Korea, 15-19 March 2004. The purpose of the symposium was to provide a forum for scientists and engineers to discuss recent progress and future trends in the rapidly advancing wide band gap semiconductor science and technologies and their applications in blue laser and light emitting diodes.

  16. Time-delayed coupled logistic capacity model in population dynamics

    NASA Astrophysics Data System (ADS)

    Cáceres, Manuel O.

    2014-08-01

    This study proposes a delay-coupled system based on the logistic equation that models the interaction of a population with its varying environment. The integro-diferential equations of the model are presented in terms of a distributed time-delayed coupled logistic-capacity equation. The model eliminates the need for a prior knowledge of the maximum saturation environmental carrying capacity value. Therefore the dynamics toward the final attractor in a distributed time-delayed coupled logistic-capacity model is studied. Exact results are presented, and analytical conclusions have been done in terms of the two parameters of the model.

  17. CIDGA - Coupling of Interior Dynamic models with Global Atmosphere models

    NASA Astrophysics Data System (ADS)

    Noack, Lena; Plesa, Ana-Catalina; Breuer, Doris

    2010-05-01

    Atmosphere temperatures and in particular the surface temperatures mostly depend on the solar heat flux and the atmospheric composition. The latter can be influenced by interior processes of the planet, i.e. volcanism that releases greenhouse gases such as H2O, CO2 and methane into the atmosphere and plate tectonics through which atmospheric CO2 is recycled via carbonates into the mantle. An increasing concentration of greenhouse gases in the atmosphere results in an increase of the surface temperature. Changes in the surface temperature on the other hand may influence the cooling behaviour of the planet and hence influence its volcanic activity [Phillips et al., 2001]. This feedback relation between mantle convection and atmosphere is not very well understood, since until now mostly either the interior dynamic of a planet or its atmosphere was investigated separately. 2D or 3D mantle convection models to the authors' knowledge haven't been coupled to the atmosphere so far. We have used the 3D spherical simulation code GAIA [Hüttig et al., 2008] including partial melt production and coupled it with the atmosphere module CIDGA using a gray greenhouse model for varying H2O concentrations. This way, not only the influence of mantle dynamics on the atmosphere can be investigated, but also the recoupling effect, that the surface temperature has on the mantle dynamics. So far, we consider one-plate planets without crustal and thus volatile recycling. Phillips et al. [2001] already investigated the coupling effect of the surface temperature on mantle dynamics by using simple parameterized convection models for Venus. In their model a positive feedback mechanism has been observed, i.e., an increase of the surface temperature leads to an increase of partial melt and hence an increase of atmosphere density and surface temperature. Applying our model to Venus, we show that an increase of surface temperature leads not only to an increase of partial melt in the mantle; it also

  18. Quark-meson coupling model with the cloudy bag

    SciTech Connect

    Nagai, S.; Miyatsu, T.; Saito, Kenji; Tsushima, Kazuo

    2008-07-01

    Using the volume coupling version of the cloudy bag model, the quark-meson coupling model is extended to study the role of pion field and the properties of nuclear matter. The extended model includes the effect of gluon exchange as well as the pion-cloud effect, and provides a good description of the nuclear matter properties. The relationship between the extended model and the EFT approach to nuclear matter is also discussed.

  19. D3-Equivariant coupled advertising oscillators model

    NASA Astrophysics Data System (ADS)

    Zhang, Chunrui; Zheng, Huifeng

    2011-04-01

    A ring of three coupled advertising oscillators with delay is considered. Using the symmetric functional differential equation theories, the multiple Hopf bifurcations of the equilibrium at the origin are demonstrated. The existence of multiple branches of bifurcating periodic solution is obtained. Numerical simulation supports our analysis results.

  20. Synchronized action of synaptically coupled chaotic model neurons.

    PubMed

    Abarbanel, H D; Huerta, R; Rabinovich, M I; Rulkov, N F; Rowat, P F; Selverston, A I

    1996-11-15

    Experimental observations of the intracellular recorded electrical activity in individual neurons show that the temporal behavior is often chaotic. We discuss both our own observations on a cell from the stomatogastric central pattern generator of lobster and earlier observations in other cells. In this paper we work with models with chaotic neurons, building on models by Hindmarsh and Rose for bursting, spiking activity in neurons. The key feature of these simplified models of neurons is the presence of coupled slow and fast subsystems. We analyze the model neurons using the same tools employed in the analysis of our experimental data. We couple two model neurons both electrotonically and electrochemically in inhibitory and excitatory fashions. In each of these cases, we demonstrate that the model neurons can synchronize in phase and out of phase depending on the strength of the coupling. For normal synaptic coupling, we have a time delay between the action of one neuron and the response of the other. We also analyze how the synchronization depends on this delay. A rich spectrum of synchronized behaviors is possible for electrically coupled neurons and for inhibitory coupling between neurons. In synchronous neurons one typically sees chaotic motion of the coupled neurons. Excitatory coupling produces essentially periodic voltage trajectories, which are also synchronized. We display and discuss these synchronized behaviors using two "distance" measures of the synchronization. PMID:8888609

  1. Effects of the 5th and 7th Grade Enhanced Versions of the "keepin' it REAL" Substance Use Prevention Curriculum

    ERIC Educational Resources Information Center

    Elek, Elvira; Wagstaff, David A.; Hecht, Michael L.

    2010-01-01

    This study assessed the outcomes of adapting the culturally-grounded, middle school, substance-use prevention intervention, "keepin' it REAL" ("kiR"), to target elementary school students and to address acculturation. At the beginning of 5th grade, 29 schools were randomly assigned to conditions obtained by crossing grade of implementation (5th,…

  2. Measuring Listening Comprehension Skills of 5th Grade School Students with the Help of Web Based System

    ERIC Educational Resources Information Center

    Acat, M. Bahaddin; Demiral, Hilmi; Kaya, Mehmet Fatih

    2016-01-01

    The main purpose of this study is to measure listening comprehension skills of 5th grade school students with the help of web based system. This study was conducted on 5th grade students studying at the primary schools of Eskisehir. The scale used in the process of the study is "Web Based Listening Scale". In the process of the study,…

  3. Graphical models of residue coupling in protein families.

    PubMed

    Thomas, John; Ramakrishnan, Naren; Bailey-Kellogg, Chris

    2008-01-01

    Many statistical measures and algorithmic techniques have been proposed for studying residue coupling in protein families. Generally speaking, two residue positions are considered coupled if, in the sequence record, some of their amino acid type combinations are significantly more common than others. While the proposed approaches have proven useful in finding and describing coupling, a significant missing component is a formal probabilistic model that explicates and compactly represents the coupling, integrates information about sequence,structure, and function, and supports inferential procedures for analysis, diagnosis, and prediction.We present an approach to learning and using probabilistic graphical models of residue coupling. These models capture significant conservation and coupling constraints observable ina multiply-aligned set of sequences. Our approach can place a structural prior on considered couplings, so that all identified relationships have direct mechanistic explanations. It can also incorporate information about functional classes, and thereby learn a differential graphical model that distinguishes constraints common to all classes from those unique to individual classes. Such differential models separately account for class-specific conservation and family-wide coupling, two different sources of sequence covariation. They are then able to perform interpretable functional classification of new sequences, explaining classification decisions in terms of the underlying conservation and coupling constraints. We apply our approach in studies of both G protein-coupled receptors and PDZ domains, identifying and analyzing family-wide and class-specific constraints, and performing functional classification. The results demonstrate that graphical models of residue coupling provide a powerful tool for uncovering, representing, and utilizing significant sequence structure-function relationships in protein families. PMID:18451428

  4. Model of globally coupled Duffing flows

    NASA Astrophysics Data System (ADS)

    Shimada, Tokuzo; Moriya, Takanobu

    2014-03-01

    A Duffing oscillator in a certain parameter range shows period-doubling that has the same Feigenbaum ratio as the logistic map, which is an important issue in universality in chaos. In this paper a globally coupled lattice of Duffing flows (GCFL), which is a natural extension of the globally coupled logistic map lattice (GCML), is constructed. It is observed that GCFL inherits various intriguing properties of GCML and that universality at the level of elements is thus lifted to that of systems. Phase diagrams for GCFL are determined, which are essentially the same as those for GCML. Similar to the two-clustered periodic attractor of GCML, the GCFL two-clustered attractor exhibits a successive period-doubling with an increase of population imbalance between the clusters (\\vartheta -bifurcation). A nontrivial distinction between the GCML and GCFL attractors that originates from the symmetry in the Duffing equation is investigated in detail.

  5. Modeling of Inner Magnetosphere Coupling Processes

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2011-01-01

    The Ring Current (RC) is the biggest energy player in the inner magnetosphere. It is the source of free energy for Electromagnetic Ion Cyclotron (EMIC) wave excitation provided by a temperature anisotropy of RC ions, which develops naturally during inward E B convection from the plasmasheet. The cold plasmasphere, which is under the strong influence of the magnetospheric electric field, strongly mediates the RC-EMIC wave-particle-coupling process and ultimately becomes part of the particle and energy interplay. On the other hand, there is a strong influence of the RC on the inner magnetospheric electric and magnetic field configurations and these configurations, in turn, are important to RC dynamics. Therefore, one of the biggest needs for inner magnetospheric research is the continued progression toward a coupled, interconnected system with the inclusion of nonlinear feedback mechanisms between the plasma populations, the electric and magnetic fields, and plasma waves. As we clearly demonstrated in our studies, EMIC waves strongly interact with electrons and ions of energies ranging from approx.1 eV to approx.10 MeV, and that these waves strongly affect the dynamics of resonant RC ions, thermal electrons and ions, and the outer RB relativistic electrons. As we found, the rate of ion and electron scattering/heating in the Earth's magnetosphere is not only controlled by the wave intensity-spatial-temporal distribution but also strongly depends on the spectral distribution of the wave power. The latter is also a function of the plasmaspheric heavy ion content, and the plasma density and temperature distributions along the magnetic field lines. The above discussion places RC-EMIC wave coupling dynamics in context with inner magnetospheric coupling processes and, ultimately, relates RC studies with plasmaspheric and Superthermal Electrons formation processes as well as with outer RB physics.

  6. Exact solutions for a coupled nonlocal model of nanobeams

    SciTech Connect

    Marotti de Sciarra, Francesco E-mail: raffaele.barretta@unina.it; Barretta, Raffaele E-mail: raffaele.barretta@unina.it

    2014-10-06

    BERNOULLI-EULER nanobeams under concentrated forces/couples with the nonlocal constitutive behavior proposed by ERINGEN do not exhibit small-scale effects. A new model obtained by coupling the ERINGEN and gradient models is formulated in the present note. A variational treatment is developed by imposing suitable thermodynamic restrictions for nonlocal models and the ensuing differential and boundary conditions of elastic equilibrium are provided. The nonlocal elastostatic problem is solved in a closed-form for nanocantilever and clamped nanobeams.

  7. Coupling entropy of co-processing model on social networks

    NASA Astrophysics Data System (ADS)

    Zhang, Zhanli

    2015-08-01

    Coupling entropy of co-processing model on social networks is investigated in this paper. As one crucial factor to determine the processing ability of nodes, the information flow with potential time lag is modeled by co-processing diffusion which couples the continuous time processing and the discrete diffusing dynamics. Exact results on master equation and stationary state are achieved to disclose the formation. In order to understand the evolution of the co-processing and design the optimal routing strategy according to the maximal entropic diffusion on networks, we propose the coupling entropy comprehending the structural characteristics and information propagation on social network. Based on the analysis of the co-processing model, we analyze the coupling impact of the structural factor and information propagating factor on the coupling entropy, where the analytical results fit well with the numerical ones on scale-free social networks.

  8. Preface to Special Topic: Selected Papers from the 5th International Conference on Optofluidics.

    PubMed

    Fan, Shih-Kang; Yang, Zhenchuan

    2016-01-01

    The 5th International Conference on Optofluidics (Optofluidics 2015) was held in Taipei, Taiwan, July 26-29, 2015. The aim of this conference was to provide a forum to promote scientific exchange and to foster closer networks and collaborative ties between leading international researchers in optics and micro/nanofluidics across various disciplines. The scope of Optofluidics 2015 was deliberately broad and interdisciplinary, encompassing the latest advances and the most innovative developments in micro/nanoscale science and technology. Topics ranged from fundamental research to its applications in chemistry, physics, biology, materials, and medicine. PMID:27076863

  9. Preface to Special Topic: Selected Papers from the 5th International Conference on Optofluidics

    PubMed Central

    Fan, Shih-Kang; Yang, Zhenchuan

    2016-01-01

    The 5th International Conference on Optofluidics (Optofluidics 2015) was held in Taipei, Taiwan, July 26–29, 2015. The aim of this conference was to provide a forum to promote scientific exchange and to foster closer networks and collaborative ties between leading international researchers in optics and micro/nanofluidics across various disciplines. The scope of Optofluidics 2015 was deliberately broad and interdisciplinary, encompassing the latest advances and the most innovative developments in micro/nanoscale science and technology. Topics ranged from fundamental research to its applications in chemistry, physics, biology, materials, and medicine. PMID:27076863

  10. A Social Medium: ASM's 5th Cell-Cell Communication in Bacteria Meeting in Review

    PubMed Central

    Federle, Michael J.

    2015-01-01

    The 5th American Society for Microbiology Conference on Cell-Cell Communication in Bacteria (CCCB-5), which convened from 18 to 21 October 2014 in San Antonio, TX, highlighted recent advances in our understanding of microbial intercellular signaling. While the CCCB meetings arose from interests in pheromone signaling and quorum sensing, it was evident at CCCB-5 that the cell-cell communication field is continuing to mature, expanding into new areas and integrating cutting-edge technologies. In this minireview, we recap some of the research discussed at CCCB-5 and the questions that have arisen from it. PMID:25917904

  11. Overview of the Coupled Model Intercomparison Project (CMIP)

    SciTech Connect

    Meehl, G A; Covey, C; McAvaney, B; Latif, M; Stouffer, R J

    2004-08-05

    The Coupled Model Intercomparison Project (CMIP) is designed to allow study and intercomparison of multi-model simulations of present-day and future climate. The latter are represented by idealized forcing of compounded 1% per year CO2 increase to the time of CO2 doubling near year 70 in simulations with global coupled models that contain, typically, components representing atmosphere, ocean, sea ice and land surface. Results from CMIP diagnostic subprojects were presented at the Second CMIP Workshop held at the Max Planck Institute for Meteorology in Hamburg, Germany, in September, 2003. Significant progress in diagnosing and understanding results from global coupled models has been made since the First CMIP Workshop in Melbourne, Australia in 1998. For example, the issue of flux adjustment is slowly fading as more and more models obtain stable multi-century surface climates without them. El Nino variability, usually about half the observed amplitude in the previous generation of coupled models, is now more accurately simulated in the present generation of global coupled models, though there are still biases in simulating the patterns of maximum variability. Typical resolutions of atmospheric component models contained in coupled models is now usually around 2.5 degrees latitude-longitude, with the ocean components often having about twice the atmospheric model resolution, with even higher resolution in the equatorial tropics. Some new-generation coupled models have atmospheric model resolutions of around 1.5 degrees latitude-longitude. Modeling groups now routinely run the CMIP control and 1% CO2 simulations in addition to 20th and 21st century climate simulations with a variety of forcings (e.g. volcanoes, solar variability, anthropogenic sulfate aerosols, ozone, and greenhouse gases (GHGs), with the anthropogenic forcings for future climate as well). However, persistent systematic errors noted in previous generations of global coupled models still are present

  12. Perturbative unification of gauge couplings in supersymmetric E6 models

    NASA Astrophysics Data System (ADS)

    Cho, Gi-Chol; Maru, Nobuhito; Yotsutani, Kaho

    2016-07-01

    We study gauge coupling unification in supersymmetric (SUSY) E6 models where an additional U(1)‧ gauge symmetry is broken near the TeV scale and a number of exotic matter fields from the 27 representations have O(TeV) mass. Solving the two-loop renormalization group equations (RGE) of gauge couplings and a kinetic mixing coupling between the U(1)‧ and U(1)Y gauge fields, we find that the gauge couplings fall into the non-perturbative regime below the grand unified theories (GUT) scale. We examine threshold corrections on the running of gauge couplings from both light and heavy ( ˜ GUT scale) particles and show constraints on the size of corrections to achieve the perturbative unification of gauge couplings.

  13. Coupled thermomechanical modeling using dissimilar geometries in arpeggio.

    SciTech Connect

    Kostka, Timothy D.; Templeton, Jeremy Alan

    2010-11-01

    Performing coupled thermomechanical simulations is becoming an increasingly important aspect of nuclear weapon (NW) safety assessments in abnormal thermal environments. While such capabilities exist in SIERRA, they have thus far been used only in a limited sense to investigate NW safety themes. An important limiting factor is the difficulty associated with developing geometries and meshes appropriate for both thermal and mechanical finite element models, which has limited thermomechanical analysis to simplified configurations. This work addresses the issue of how to perform coupled analyses on models where the underlying geometries and associated meshes are different and tailored to their relevant physics. Such an approach will reduce the model building effort and enable previously developed single-physics models to be leveraged in future coupled simulations. A combined-environment approach is presented in this report using SIERRA tools, with quantitative comparisons made between different options in SIERRA. This report summarizes efforts on running a coupled thermomechanical analysis using the SIERRA Arpeggio code.

  14. Two-level parabolic model with phase-jump coupling

    NASA Astrophysics Data System (ADS)

    Lehto, J. M. S.; Suominen, K.-A.

    2016-07-01

    We study the coherent dynamics of a two-level parabolic model and ways to enhance population transfer and even to obtain complete population inversion in such models. Motivated by the complete population inversion effect of zero-area pulses found in [Phys. Rev. A 73, 023416 (2006), 10.1103/PhysRevA.73.023416], we consider a scheme where a given coupling function is transformed to a zero-area coupling by performing a phase jump in the middle of the evolution. With a phase-jump coupling, complete population inversion can be achieved with relatively small coupling. In the case of Zener tunneling, complete population inversion is obtained for strong-enough coupling regardless of the height of the tunneling barrier. We also derive a universal formula for the effect of the phase jump.

  15. Nuclear Hybrid Energy System Modeling: RELAP5 Dynamic Coupling Capabilities

    SciTech Connect

    Piyush Sabharwall; Nolan Anderson; Haihua Zhao; Shannon Bragg-Sitton; George Mesina

    2012-09-01

    The nuclear hybrid energy systems (NHES) research team is currently developing a dynamic simulation of an integrated hybrid energy system. A detailed simulation of proposed NHES architectures will allow initial computational demonstration of a tightly coupled NHES to identify key reactor subsystem requirements, identify candidate reactor technologies for a hybrid system, and identify key challenges to operation of the coupled system. This work will provide a baseline for later coupling of design-specific reactor models through industry collaboration. The modeling capability addressed in this report focuses on the reactor subsystem simulation.

  16. 5th Bionanotox and Applications International Research Conference, Peabody, Little Rock, Arkansas, USA

    NASA Astrophysics Data System (ADS)

    Sabb, Taneicie; Chowdhury, Parimal

    2011-06-01

    "BioNanoTox and Toxicity: using Technology to Advance Discovery" was this year's theme at the 5th BioNanoTox and Applications International Research Conference held at the Peabody Hotel, Little Rock, Arkansas on November 4-5th, 2010. This year, the international participation in this conference increased to 25 countries spanning the globe. The conference began with opening remarks by Paul Howard, Associate Director of the National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas, United States. Two keynote speakers, Dr. Ananth V. Annapragada and Dr. Merle G. Paule presented lectures on "Toxicity of Novel Nanoparticles for CT imaging" and "The Biology of Neurotoxicity: using Technology to Advance Discovery", respectively. Teachers, students, faculty, and scientists presented oral and poster presentations on fundamental and translational research related to BioNanoTox and related fields of science. Six presentation sessions were held over the two-day conference. There were 31 presentations and 39 posters from disciplines ranging from biology to chemistry, toxicology, nanotechnology, computational sciences, mathematics, engineering, plant science, and biotechnology. Poster presentation awards were presented to three high school students, three high school teachers, and three college students. In addition to poster awards a memorial, travel, and BioNanoTox award were presented. This year's meeting paved the way for a more outstanding meeting for the future.

  17. Coupled land surface/hydrologic/atmospheric models

    NASA Technical Reports Server (NTRS)

    Pielke, Roger; Steyaert, Lou; Arritt, Ray; Lahtakia, Mercedes; Smith, Chris; Ziegler, Conrad; Soong, Su Tzai; Avissar, Roni; Wetzel, Peter; Sellers, Piers

    1993-01-01

    The topics covered include the following: prototype land cover characteristics data base for the conterminous United States; surface evapotranspiration effects on cumulus convection and implications for mesoscale models; the use of complex treatment of surface hydrology and thermodynamics within a mesoscale model and some related issues; initialization of soil-water content for regional-scale atmospheric prediction models; impact of surface properties on dryline and MCS evolution; a numerical simulation of heavy precipitation over the complex topography of California; representing mesoscale fluxes induced by landscape discontinuities in global climate models; emphasizing the role of subgrid-scale heterogeneity in surface-air interaction; and problems with modeling and measuring biosphere-atmosphere exchanges of energy, water, and carbon on large scales.

  18. Accurate theoretical chemistry with coupled pair models.

    PubMed

    Neese, Frank; Hansen, Andreas; Wennmohs, Frank; Grimme, Stefan

    2009-05-19

    Quantum chemistry has found its way into the everyday work of many experimental chemists. Calculations can predict the outcome of chemical reactions, afford insight into reaction mechanisms, and be used to interpret structure and bonding in molecules. Thus, contemporary theory offers tremendous opportunities in experimental chemical research. However, even with present-day computers and algorithms, we cannot solve the many particle Schrodinger equation exactly; inevitably some error is introduced in approximating the solutions of this equation. Thus, the accuracy of quantum chemical calculations is of critical importance. The affordable accuracy depends on molecular size and particularly on the total number of atoms: for orientation, ethanol has 9 atoms, aspirin 21 atoms, morphine 40 atoms, sildenafil 63 atoms, paclitaxel 113 atoms, insulin nearly 800 atoms, and quaternary hemoglobin almost 12,000 atoms. Currently, molecules with up to approximately 10 atoms can be very accurately studied by coupled cluster (CC) theory, approximately 100 atoms with second-order Møller-Plesset perturbation theory (MP2), approximately 1000 atoms with density functional theory (DFT), and beyond that number with semiempirical quantum chemistry and force-field methods. The overwhelming majority of present-day calculations in the 100-atom range use DFT. Although these methods have been very successful in quantum chemistry, they do not offer a well-defined hierarchy of calculations that allows one to systematically converge to the correct answer. Recently a number of rather spectacular failures of DFT methods have been found-even for seemingly simple systems such as hydrocarbons, fueling renewed interest in wave function-based methods that incorporate the relevant physics of electron correlation in a more systematic way. Thus, it would be highly desirable to fill the gap between 10 and 100 atoms with highly correlated ab initio methods. We have found that one of the earliest (and now

  19. Coupled oscillator model for nonlinear gravitational perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Huan; Zhang, Fan; Green, Stephen R.; Lehner, Luis

    2015-04-01

    Motivated by the gravity-fluid correspondence, we introduce a new method for characterizing nonlinear gravitational interactions. Namely we map the nonlinear perturbative form of the Einstein equation to the equations of motion of a collection of nonlinearly coupled harmonic oscillators. These oscillators correspond to the quasinormal or normal modes of the background spacetime. We demonstrate the mechanics and the utility of this formalism within the context of perturbed asymptotically anti-de Sitter black brane spacetimes. We confirm in this case that the boundary fluid dynamics are equivalent to those of the hydrodynamic quasinormal modes of the bulk spacetime. We expect this formalism to remain valid in more general spacetimes, including those without a fluid dual. In other words, although born out of the gravity-fluid correspondence, the formalism is fully independent and it has a much wider range of applicability. In particular, as this formalism inspires an especially transparent physical intuition, we expect its introduction to simplify the often highly technical analytical exploration of nonlinear gravitational dynamics.

  20. Coupled Oscillator Model for Nonlinear Gravitational Perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Huan; Zhang, Fan; Green, Stephen; Lehner, Luis

    2015-04-01

    Motivated by the fluid/gravity correspondence, we introduce a new method for characterizing nonlinear gravitational interactions. Namely we map the nonlinear perturbative form of the Einstein's equation to the equations of motion of a series of nonlinearly-coupled harmonic oscillators. These oscillators correspond to the quasinormal modes of the background spacetime. We demonstrate the mechanics and the utility of this formalism with an asymptotically AdS black-brane spacetime, where the equations of motion for the oscillators are shown to be equivalent to the Navier-Stokes equation for the boundary fluid in the mode-expansion picture. We thereby expand on the explicit correspondence connecting the fluid and gravity sides for this particular physical set-up. Perhaps more importantly, we expect this formalism to remain valid in more general spacetimes, including those without a fluid/gravity correspondence. In other words, although born out of the correspondence, the formalism survives independently of it and has a much wider range of applicability.

  1. The Coupled Chemical and Physical Dynamics Model of MALDI.

    PubMed

    Knochenmuss, Richard

    2016-06-12

    The coupled physical and chemical dynamics model of ultraviolet matrix-assisted laser desorption/ionization (MALDI) has reproduced and explained a wide variety of MALDI phenomena. The rationale behind and elements of the model are reviewed, including the photophysics, kinetics, and thermodynamics of primary and secondary reaction steps. Experimental results are compared with model predictions to illustrate the foundations of the model, coupling of ablation and ionization, differences between and commonalities of matrices, secondary charge transfer reactions, ionization in both polarities, fluence and concentration dependencies, and suppression and enhancement effects. PMID:27070182

  2. Finite Element Modelling of Fluid Coupling in the Coiled Cochlea

    NASA Astrophysics Data System (ADS)

    Ni, Guangjian; Elliott, S. J.; Lineton, B.; Saba, R.

    2011-11-01

    A finite element model is first used to calculate the modal pressure difference for a box model of the cochlea, which shows that the number of fluid elements across the width of the cochlea determines the accuracy with which the near field, or short wavenumber, component of the fluid coupling is reproduced. Then results are compared with the analytic results to validate the accuracy of the FE model. It is, however, the far field, or long wavelength, component of the fluid coupling that is most affected by the geometry. A finite element model of the coiled cochlea is then used to calculate fluid coupling in this case, which has similar characteristics to the uncoiled model.

  3. ITG sideband coupling models for zonal flows

    SciTech Connect

    Stransky, M.

    2011-05-15

    Four-wave interaction model between ITG mode and zonal flow was derived using fluid equations. In this model, the zonal flow is excited non-linearly by ITG turbulence via Reynolds stress. Numerical simulations show that the system allows for a small range above the ITG threshold where the zonal flow can stabilize an unstable ITG mode, effectively increasing {eta}{sub i} threshold, an effect which has been called the Dimits shift. However, the shift is smaller than in known cases such that in the Cyclone base.

  4. A Dynamic Coupled Magnetosphere-Ionosphere-Ring Current Model

    NASA Astrophysics Data System (ADS)

    Pembroke, Asher

    In this thesis we describe a coupled model of Earth's magnetosphere that consists of the Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamics (MHD) simulation, the MIX ionosphere solver and the Rice Convection Model (RCM). We report some results of the coupled model using idealized inputs and model parameters. The algorithmic and physical components of the model are described, including the transfer of magnetic field information and plasma boundary conditions to the RCM and the return of ring current plasma properties to the LFM. Crucial aspects of the coupling include the restriction of RCM to regions where field-line averaged plasma-beta ¡=1, the use of a plasmasphere model, and the MIX ionosphere model. Compared to stand-alone MHD, the coupled model produces a substantial increase in ring current pressure and reduction of the magnetic field near the Earth. In the ionosphere, stronger region-1 and region-2 Birkeland currents are seen in the coupled model but with no significant change in the cross polar cap potential drop, while the region-2 currents shielded the low-latitude convection potential. In addition, oscillations in the magnetic field are produced at geosynchronous orbit with the coupled code. The diagnostics of entropy and mass content indicate that these oscillations are associated with low-entropy flow channels moving in from the tail and may be related to bursty bulk flows and bubbles seen in observations. As with most complex numerical models, there is the ongoing challenge of untangling numerical artifacts and physics, and we find that while there is still much room for improvement, the results presented here are encouraging. Finally, we introduce several new methods for magnetospheric visualization and analysis, including a fluid-spatial volume for RCM and a field-aligned analysis mesh for the LFM. The latter allows us to construct novel visualizations of flux tubes, drift surfaces, topological boundaries, and bursty-bulk flows.

  5. A multicomponent coupled model of glacier hydrology

    NASA Astrophysics Data System (ADS)

    Flowers, Gwenn Elizabeth

    Multiple lines of evidence suggest a causal link between subglacial hydrology and phenomena such as fast-flowing ice. This evidence includes a measured correlation between water under alpine glaciers and their motion, the presence of saturated sediment beneath Antaxctic ice streams, and geologic signatures of enhanced paleo-ice flow over deformable substrates. The complexity of the glacier bed as a three-component mixture presents an obstacle to unraveling these conundra. Inadequate representations of hydrology, in part, prevent us from closing the gap between empirical descriptions and a comprehensive consistent framework for understanding the dynamics of glacierized systems. I have developed a distributed numerical model that solves equations governing glacier surface runoff, englacial water transport, subglacial drainage, and subsurface groundwater flow. Ablation and precipitation drive the surface model through a temperature-index parameterization. Water is permitted to flow over and off the glacier, or to the bed through a system of crevasses, pipes, and fractures. A macroporous sediment horizon transports subglacial water to the ice margin or to an underlying aquifer. Governing equations are derived from the law of mass conservation and are expressed as a balance between the internal redistribution of water and external sources. Each of the four model components is represented as a two-dimensional, vertically-integrated layer that communicates with its neighbors through water exchange. Stacked together, these layers approximate a three-dimensional system. I tailor the model to Trapridge Glacier, where digital maps of the surface and bed have been derived from ice-penetrating radar data. Observations of subglacial water pressure provide additional constraints on model parameters and a basis for comparison of simulations with real data. Three classical idealizations of glacier geometry are used for simple model experiments. Equilibrium tests emphasize geometric

  6. EDITORIAL: 'Best article' prize for the 5th anniversary of Environmental Research Letters 'Best article' prize for the 5th anniversary of Environmental Research Letters

    NASA Astrophysics Data System (ADS)

    Kammen, Dan; Wright, Guillaume

    2011-12-01

    To celebrate the 5th anniversary of Environmental Research Letters (ERL) the publishers of the journal, IOP Publishing, have awarded a prize for the five best articles published in ERL since the journal began in 2006. The procedure for deciding the winning articles was as thorough as possible to ensure that the most outstanding articles would win the prize. A shortlist of 25 nominated research articles, five for each year since ERL was launched, which were chosen based on a range of criteria including novelty, scientific impact, readership, broad appeal and wider media coverage, was selected. The ERL Editorial Board then assessed and rated these 25 articles in order to choose a winning article for each year. We would like to announce that the following articles have been awarded ERL's 5th anniversary best article prize: 2006/7 The Bodélé depression: a single spot in the Sahara that provides most of the mineral dust to the Amazon forest Ilan Koren, Yoram J Kaufman, Richard Washington, Martin C Todd, Yinon Rudich, J Vanderlei Martins and Daniel Rosenfeld 2006 Environ. Res. Lett. 1 014005 2008 Causes and impacts of the 2005 Amazon drought Ning Zeng, Jin-Ho Yoon, Jose A Marengo, Ajit Subramaniam, Carlos A Nobre, Annarita Mariotti and J David Neelin 2008 Environ. Res. Lett. 3 014002 2009 How difficult is it to recover from dangerous levels of global warming? J A Lowe, C Huntingford, S C B Raper, C D Jones, S K Liddicoat and L K Gohar 2009 Environ. Res. Lett. 4 014012 2010 Is physical water scarcity a new phenomenon? Global assessment of water shortage over the last two millennia Matti Kummu, Philip J Ward, Hans de Moel and Olli Varis 2010 Environ. Res. Lett. 5 034006 2011 Implications of urban structure on carbon consumption in metropolitan areas Jukka Heinonen and Seppo Junnila 2011 Environ. Res. Lett. 6 014018 Our congratulations go to these authors. In recognition of their outstanding work, we are delighted to offer all of the authors of the winning articles free

  7. EDITORIAL: 'Best article' prize for the 5th anniversary of Environmental Research Letters 'Best article' prize for the 5th anniversary of Environmental Research Letters

    NASA Astrophysics Data System (ADS)

    Kammen, Dan; Wright, Guillaume

    2011-12-01

    To celebrate the 5th anniversary of Environmental Research Letters (ERL) the publishers of the journal, IOP Publishing, have awarded a prize for the five best articles published in ERL since the journal began in 2006. The procedure for deciding the winning articles was as thorough as possible to ensure that the most outstanding articles would win the prize. A shortlist of 25 nominated research articles, five for each year since ERL was launched, which were chosen based on a range of criteria including novelty, scientific impact, readership, broad appeal and wider media coverage, was selected. The ERL Editorial Board then assessed and rated these 25 articles in order to choose a winning article for each year. We would like to announce that the following articles have been awarded ERL's 5th anniversary best article prize: 2006/7 The Bodélé depression: a single spot in the Sahara that provides most of the mineral dust to the Amazon forest Ilan Koren, Yoram J Kaufman, Richard Washington, Martin C Todd, Yinon Rudich, J Vanderlei Martins and Daniel Rosenfeld 2006 Environ. Res. Lett. 1 014005 2008 Causes and impacts of the 2005 Amazon drought Ning Zeng, Jin-Ho Yoon, Jose A Marengo, Ajit Subramaniam, Carlos A Nobre, Annarita Mariotti and J David Neelin 2008 Environ. Res. Lett. 3 014002 2009 How difficult is it to recover from dangerous levels of global warming? J A Lowe, C Huntingford, S C B Raper, C D Jones, S K Liddicoat and L K Gohar 2009 Environ. Res. Lett. 4 014012 2010 Is physical water scarcity a new phenomenon? Global assessment of water shortage over the last two millennia Matti Kummu, Philip J Ward, Hans de Moel and Olli Varis 2010 Environ. Res. Lett. 5 034006 2011 Implications of urban structure on carbon consumption in metropolitan areas Jukka Heinonen and Seppo Junnila 2011 Environ. Res. Lett. 6 014018 Our congratulations go to these authors. In recognition of their outstanding work, we are delighted to offer all of the authors of the winning articles free

  8. Coupled Facility/Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at NASA/GSFC there is an analysis to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combination of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  9. Coupled Facility-Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael A.

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at National Aeronautics and Space Administration/Goddard Space Flight Center an analysis is performed to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combined dynamics of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA/Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  10. Strong Local-Nonlocal Coupling for Integrated Fracture Modeling

    SciTech Connect

    Littlewood, David John; Silling, Stewart A.; Mitchell, John A.; Seleson, Pablo D.; Bond, Stephen D.; Parks, Michael L.; Turner, Daniel Z.; Burnett, Damon J.; Ostien, Jakob; Gunzburger, Max

    2015-09-01

    Peridynamics, a nonlocal extension of continuum mechanics, is unique in its ability to capture pervasive material failure. Its use in the majority of system-level analyses carried out at Sandia, however, is severely limited, due in large part to computational expense and the challenge posed by the imposition of nonlocal boundary conditions. Combined analyses in which peridynamics is em- ployed only in regions susceptible to material failure are therefore highly desirable, yet available coupling strategies have remained severely limited. This report is a summary of the Laboratory Directed Research and Development (LDRD) project "Strong Local-Nonlocal Coupling for Inte- grated Fracture Modeling," completed within the Computing and Information Sciences (CIS) In- vestment Area at Sandia National Laboratories. A number of challenges inherent to coupling local and nonlocal models are addressed. A primary result is the extension of peridynamics to facilitate a variable nonlocal length scale. This approach, termed the peridynamic partial stress, can greatly reduce the mathematical incompatibility between local and nonlocal equations through reduction of the peridynamic horizon in the vicinity of a model interface. A second result is the formulation of a blending-based coupling approach that may be applied either as the primary coupling strategy, or in combination with the peridynamic partial stress. This blending-based approach is distinct from general blending methods, such as the Arlequin approach, in that it is specific to the coupling of peridynamics and classical continuum mechanics. Facilitating the coupling of peridynamics and classical continuum mechanics has also required innovations aimed directly at peridynamic models. Specifically, the properties of peridynamic constitutive models near domain boundaries and shortcomings in available discretization strategies have been addressed. The results are a class of position-aware peridynamic constitutive laws for

  11. Exploratory Factor Analysis of Diagnostic and Statistical Manual, 5th Edition, Criteria for Posttraumatic Stress Disorder.

    PubMed

    McSweeney, Lauren B; Koch, Ellen I; Saules, Karen K; Jefferson, Stephen

    2016-01-01

    One change to the posttraumatic stress disorder (PTSD) nomenclature highlighted in the Diagnostic and Statistical Manual, 5th Edition (DSM-5; American Psychiatric Association, 2013) is the conceptualization of PTSD as a diagnostic category with four distinct symptom clusters. This article presents exploratory factor analysis to test the structural validity of the DSM-5 conceptualization of PTSD via an online survey that included the PTSD Checklist-5. The study utilized a sample of 113 college students from a large Midwestern university and 177 Amazon Mechanical Turk users. Participants were primarily female, Caucasian, single, and heterosexual with an average age of 32 years. Approximately 30% to 35% of participants met diagnostic criteria for PTSD based on two different scoring criteria. Results of the exploratory factor analysis revealed five distinct symptom clusters. The implications for the classification of PTSD are discussed. PMID:26669983

  12. Genomics into Healthcare: The 5th Pan Arab Human Genetics Conference and 2013 Golden Helix Symposium

    PubMed Central

    Fortina, Paolo; AlKhaja, Najib; Al Ali, Mahmoud Taleb; Hamzeh, Abdul Rezzak; Nair, Pratibha; Innocenti, Federico; Patrinos, George P.; Kricka, Larry J.

    2014-01-01

    The joint 5th Pan Arab Human Genetics conference and 2013 Golden Helix Symposium, “Genomics into Healthcare” was coorganized by the Center for Arab Genomic Studies (http://www.cags.org.ae) in collaboration with the Golden Helix Foundation (http://www.goldenhelix.org) in Dubai, United Arab Emirates from 17 to 19 November, 2013. The meeting was attended by over 900 participants, doctors and biomedical students from over 50 countries and was organized into a series of nine themed sessions that covered cancer genomics and epigenetics, genomic and epigenetic studies, genomics of blood and metabolic disorders, cytogenetic diagnosis and molecular profiling, next-generation sequencing, consanguinity and hereditary diseases, clinical genomics, clinical applications of pharmacogenomics, and genomics in public health. PMID:24526565

  13. Dental health in antique population of Vinkovci - Cibalae in Croatia (3rd-5th century).

    PubMed

    Peko, Dunja; Vodanović, Marin

    2016-08-01

    Roman city Cibalae (Vinkovci) - the birthplace of Roman emperors Valentinian I and Valens was a very well developed urban ares in the late antique what was evidenced by numerous archaeological findings. The aim of this paper is to get insight in dental health of antique population of Cibalae. One hundred individuals with 2041 teeth dated to 3rd - 5th century AD have been analyzed for caries, antemortem tooth loss, periapical diseases and tooth wear. Prevalence of antemortem tooth loss was 4.3% in males, 5.2% in females. Prevalence of caries per tooth was 8.4% in males, 7.0% in females. Compared to other Croatian antique sites, ancient inhabitants of Roman Cibalae had rather good dental health with low caries prevalence and no gender differences. Statistically significant difference was found between males in females in the prevalence of periapical lesions and degree of tooth wear. Periapical lesions were found only in males. PMID:27598951

  14. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

    SciTech Connect

    Morris, James R; Averill, Frank; Cooper, Valentino R

    2014-01-01

    Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.

  15. Recurrent Idiopathic Catatonia: Implications beyond the Diagnostic and Statistical Manual of Mental Disorders 5th Edition

    PubMed Central

    Caroff, Stanley N.; Hurford, Irene; Bleier, Henry R.; Gorton, Gregg E.; Campbell, E. Cabrina

    2015-01-01

    We describe a case of recurrent, life-threatening, catatonic stupor, without evidence of any associated medical, toxic or mental disorder. This case provides support for the inclusion of a separate category of “unspecified catatonia” in the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5) to be used to classify idiopathic cases, which appears to be consistent with Kahlbaum’s concept of catatonia as a distinct disease state. But beyond the limited, cross-sectional, syndromal approach adopted in DSM-5, this case more importantly illustrates the prognostic and therapeutic significance of the longitudinal course of illness in differentiating cases of catatonia, which is better defined in the Wernicke-Kleist-Leonhard classification system. The importance of differentiating cases of catatonia is further supported by the efficacy of antipsychotics in treatment of this case, contrary to conventional guidelines. PMID:26243853

  16. Non compact continuum limit of two coupled Potts models

    NASA Astrophysics Data System (ADS)

    Vernier, Éric; Lykke Jacobsen, Jesper; Saleur, Hubert

    2014-10-01

    We study two Q-state Potts models coupled by the product of their energy operators, in the regime 2 < Q ⩽ 4 where the coupling is relevant. A particular choice of weights for the square lattice is shown to be equivalent to the integrable a_3(2) vertex model. It corresponds to a selfdual system of two antiferromagnetic Potts models, coupled ferromagnetically. We derive the Bethe ansatz equations and study them numerically for two arbitrary twist angles. The continuum limit is shown to involve two compact bosons and one non compact boson, with discrete states emerging from the continuum at appropriate twists. The non compact boson entails strong logarithmic corrections to the finite-size behaviour of the scaling levels, an understanding of which allows us to correct an earlier proposal for some of the critical exponents. In particular, we infer the full set of magnetic scaling dimensions (watermelon operators) of the Potts model.

  17. Service-Oriented Approach to Coupling Earth System Models and Modeling Frameworks

    NASA Astrophysics Data System (ADS)

    Goodall, J. L.; Saint, K. D.; Ercan, M. B.; Briley, L. J.; Murphy, S.; You, H.; DeLuca, C.; Rood, R. B.

    2012-12-01

    Modeling water systems often requires coupling models across traditional Earth science disciplinary boundaries. While there has been significant effort within various Earth science disciplines (e.g., atmospheric science, hydrology, and Earth surface dynamics) to create models and, more recently, modeling frameworks, there has been less work on methods for coupling across disciplinary-specific models and modeling frameworks. We present work investigating one possible method for coupling across disciplinary-specific Earth system models and modeling frameworks: service-oriented architectures. In a service-oriented architecture, models act as distinct units or components within a system and are designed to pass well defined messages to consumers of the service. While the approach offers the potential to couple heterogeneous computational models by allowing a high degree of autonomy across models of the Earth system, there are significant scientific and technical challenges to be addressed when coupling models designed for different communities and built for different modeling frameworks. We have addressed some of these challenges through a case study where we coupled a hydrologic model compliant with the OpenMI standard with an atmospheric model compliant with the EMSF standard. In this case study, the two models were coupled through data exchanges of boundary conditions enabled by exposing the atmospheric model as a web service. A discussion of the technical and scientific challenges, some that we have addressed and others that remain open, will be presented including differences in computer architectures, data semantics, and spatial scales between the coupled models.

  18. Development of a Validated Model of Ground Coupling

    SciTech Connect

    Metz, P. D.

    1980-01-01

    A research program at Brookhaven National Laboratory (BNL) studies ground coupling, the use of the earth as a heat source/sink or storage element for solar heat pump space conditioning systems. This paper outlines the analytical and experimental research to date toward the development of an experimentally validated model of ground coupling and based on experimental results from December, 1978 to September, 1979, expores sensitivity of present model predictions to variations in thermal conductivity and other factors. Ways in which the model can be further refined are discussed.

  19. Improving data transfer for model coupling

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Liu, L.; Yang, G.; Li, R.; Wang, B.

    2015-10-01

    Data transfer, which means transferring data fields between two component models or rearranging data fields among processes of the same component model, is a fundamental operation of a coupler. Most of state-of-the-art coupler versions currently use an implementation based on the point-to-point (P2P) communication of the Message Passing Interface (MPI) (call such an implementation "P2P implementation" for short). In this paper, we reveal the drawbacks of the P2P implementation, including low communication bandwidth due to small message size, variable and big number of MPI messages, and jams during communication. To overcome these drawbacks, we propose a butterfly implementation for data transfer. Although the butterfly implementation can outperform the P2P implementation in many cases, it degrades the performance in some cases because the total message size transferred by the butterfly implementation is larger than that by the P2P implementation. To make the data transfer completely improved, we design and implement an adaptive data transfer library that combines the advantages of both butterfly implementation and P2P implementation. Performance evaluation shows that the adaptive data transfer library significantly improves the performance of data transfer in most cases and does not decrease the performance in any cases. Now the adaptive data transfer library is open to the public and has been imported into a coupler version C-Coupler1 for performance improvement of data transfer. We believe that it can also improve other coupler versions.

  20. Energy demand analytics using coupled technological and economic models

    EPA Science Inventory

    Impacts of a range of policy scenarios on end-use energy demand are examined using a coupling of MARKAL, an energy system model with extensive supply and end-use technological detail, with Inforum LIFT, a large-scale model of the us. economy with inter-industry, government, and c...

  1. Lumped-element models characterize DR coupling effects

    NASA Technical Reports Server (NTRS)

    Hearn, Chase P.

    1992-01-01

    An approach to the analysis of closely spaced resonances produced by a microstrip coupled dielectric resonator is presented. In particular, it is shown that the use of a lumped-element model significantly simplifies the analysis. An experimental verification demonstrates that the model predicts the adjacent complementary resonances to within 1.6 percent of the measured value.

  2. FULLY COUPLED "ONLINE" CHEMISTRY WITHIN THE WRF MODEL

    EPA Science Inventory

    A fully coupled "online" Weather Research and Forecasting/Chemistry (WRF/Chem) model has been developed. The air quality component of the model is fully consistent with the meteorological component; both components use the same transport scheme (mass and scalar preserving), the s...

  3. Ray-tracing simulations of coupled dark energy models

    NASA Astrophysics Data System (ADS)

    Pace, Francesco; Baldi, Marco; Moscardini, Lauro; Bacon, David; Crittenden, Robert

    2015-02-01

    Dark matter and dark energy are usually assumed to couple only gravitationally. An extension to this picture is to model dark energy as a scalar field coupled directly to cold dark matter. This coupling leads to new physical effects, such as a fifth force and a time-dependent dark matter particle mass. In this work we examine the impact that coupling has on weak lensing statistics by constructing realistic simulated weak lensing maps using ray-tracing techniques through N-body cosmological simulations. We construct maps for different lensing quantities, covering a range of scales from a few arcminutes to several degrees. The concordance Λ cold dark matter (ΛCDM) model is compared to different coupled dark energy models, described either by an exponential scalar field potential (standard coupled dark energy scenario) or by a SUGRA potential (bouncing model). We analyse several statistical quantities and our results, with sources at low redshifts are largely consistent with previous work on cosmic microwave background lensing by Carbone et al. The most significant differences from the ΛCDM model are due to the enhanced growth of the perturbations and to the effective friction term in non-linear dynamics. For the most extreme models, we see differences in the power spectra up to 40 per cent compared to the ΛCDM model. The different time evolution of the linear matter overdensity can account for most of the differences, but when controlling for this using a ΛCDM model having the same normalization, the overall signal is smaller due to the effect of the friction term appearing in the equation of motion for dark matter particles.

  4. A Coupled Atmosphere-Ocean-Wave Modeling System

    NASA Astrophysics Data System (ADS)

    Allard, R. A.; Smith, T.; Rogers, W. E.; Jensen, T. G.; Chu, P.; Campbell, T. J.

    2012-12-01

    A growing interest in the impacts that large and small scale ocean and atmospheric events (El Niño, hurricanes, etc.) have on weather forecasting has led to the coupling of atmospheric, ocean circulation and ocean wave models. The Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS™ ) consists of the Navy's atmospheric model coupled to the Navy Coastal Ocean Model (NCOM) and the wave models SWAN (Simulating WAves Nearshore) and WAVEWATCH III (WW3™). In a fully coupled mode, COAMPS, NCOM, and SWAN (or WW3) may be integrated concurrently so that currents and water levels, wave-induced stress, bottom drag, Stokes drift current, precipitation, and surface fluxes of heat, moisture, and momentum are exchanged across the air-wave-sea interface. This coupling is facilitated through the Earth System Modeling Framework (ESMF). The ESMF version of COAMPS is being transitioned to operational production centers at the Naval Oceanographic Office and the Fleet Numerical Meteorology and Oceanography Center. Highlights from validation studies for the Florida Straits, Hurricane Ivan and the Adriatic Sea will be presented. COAMPS® is a registered trademark of the Naval Research Laboratory.

  5. Coupling TOUGH2 with CLM3: Developing a Coupled Land Surface andSubsurface Model

    SciTech Connect

    Pan, Lehua; Jin, Jiming; Miller, Norman; Wu, Yu-Shu; Bodvarsson,Gudmundur

    2006-05-19

    An understanding of the hydrologic interactions among atmosphere, land surface, and subsurface is one of the keys to understanding the water cycling system that supports life on earth. The inherent coupled processes and complex feedback structures among subsystems make such interactions difficult to simulate. In this paper, we present a model that simulates the land surface and subsurface hydrologic response to meteorological forcing. This model combines a state-of-the-art land-surface model, the NCAR Community Land Model version 3 (CLM3), with a variably saturated groundwater model, TOUGH2, through an internal interface that includes flux and state variables shared by the two submodels. Specifically, TOUGH2 uses infiltration, evaporation, and root-uptake rates, calculated by CLM3, as source/sink terms in its simulation; CLM3 uses saturation and capillary pressure profiles, calculated by TOUGH2, as state variables in its simulation. This new model, CLMT2, preserves the best aspects of both submodels: the state-of-the-art modeling capability of surface energy and hydrologic processes (including snow, runoff, freezing/melting, evapotranspiration, radiation, and biophysiological processes) from CLM3 and the more realistic physical-process-based modeling capability of subsurface hydrologic processes (including heterogeneity, three-dimensional flow, seamless combining of unsaturated and saturated zone, and water table) from TOUGH2. The preliminary simulation results show that the coupled model greatly improved the predictions of the groundwater table, evapotranspiration, and surface temperature at a real watershed, as evaluated using 18 years of observed data. The new model is also ready to be coupled with an atmospheric simulation model, to form one of the first top of the atmosphere to deep groundwater atmosphere-land-surface-subsurface models.

  6. A Comparison of In-Channel Dead Zone and Hyporheic Zone Transient Storage Parameter Estimates Between a 1st and 5th Order Stream

    NASA Astrophysics Data System (ADS)

    Briggs, M.; Gooseff, M.; Morkeski, K.; Wollheim, W.; Hopkinson, C.; Peterson, B.; Vorosmarty, C.

    2007-12-01

    A major enhancement to our understanding of how watersheds function would be the ability to discriminate between in-channel dead zone ( DZ) and hyporheic zone ( HZ) transient storage, and an evaluation of how these properties scale across stream orders. The nature of DZ storage is to display faster exchange rates with the main channel and less overall sediment contact time than HZ storage. These differences have great significance to many in-stream processes such as nutrient cycling. The combination of high slope, coarse bed material and fluvial structure endemic to many 1st order streams can provide greater forcing of hyporheic flow paths than occurs within the lower gradient 5th order streams. Conversely many 5th order reaches exhibit large side pool and back eddy DZ areas not common along 1st order streams. This study builds on existing methods to delineate the DZ and HZ from the integrated signal of a conservative solute's breakthrough curve ( BTC). Data for this comparison were collected over the summer of 2007 within the Ipswich River watershed, a basin which drains into Plum Island Sound on the north shore of Massachusetts, USA. The conservative solute NaCl was injected into both a 1st order medium gradient stream and a 5th order low gradient stream. The BTCs collected in thalwegs from the NaCl injections were simulated using a version of the solute transport model OTIS containing two zones of transient storage. Hydrometric measurements of stream velocity were used to estimate average main channel cross sectional area ( A) and DZ cross sectional area ( ASDZ) for each reach to constrain parameter estimates and avoid model equifinality between the storage zones. Initial values for the exchange rate between main channel flow and DZ storage ( αDZ) were estimated from DZ BTCs. Our results indicate that although the overall storage zone is much larger in proportion to the main channel for the 1st order reach than for the 5th order reach, the percentage of median

  7. COUPLING

    DOEpatents

    Hawke, B.C.

    1963-02-26

    This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)

  8. Dynamic Coupling of Alaska Based Ecosystem and Geophysical Models into an Integrated Model

    NASA Astrophysics Data System (ADS)

    Bennett, A.; Carman, T. B.

    2012-12-01

    As scientific models and the challenges they address have grown in complexity and scope, so has interest in dynamically coupling or integrating these models. Dynamic model coupling presents software engineering challenges stemming from differences in model architectures, differences in development styles between modeling groups, and memory and run time performance concerns. The Alaska Integrated Ecosystem Modeling (AIEM) project aims to dynamically couple three independently developed scientific models so that each model can exchange run-time data with each of the other models. The models being coupled are a stochastic fire dynamics model (ALFRESCO), a permafrost model (GIPL), and a soil and vegetation model (DVM-DOS-TEM). The scientific research objectives of the AIEM project are to: 1) use the coupled models for increasing our understanding of climate change and other stressors on landscape level physical and ecosystem processes, and; 2) provide support for resource conservation planning and decision making. The objectives related to the computer models themselves are modifiability, maintainability, and performance of the coupled and individual models. Modifiability and maintainability are especially important in a research context because source codes must be continually adapted to address new scientific concepts. Performance is crucial to delivering results in a timely manner. To achieve the objectives while addressing the challenges in dynamic model coupling, we have designed an architecture that emphasizes high cohesion for each individual model and loose coupling between the models. Each model will retain the ability to run independently, or to be available as a linked library to the coupled model. Performance is facilitated by parallelism in the spatial dimension. With close collaboration among modeling groups, the methodology described here has demonstrated the feasibility of coupling complex ecological and geophysical models to provide managers with more

  9. Preliminary investigation of models of coupled clocks and coupled driven pendulums

    NASA Astrophysics Data System (ADS)

    LeBailly, Christopher A.

    In this paper we study a phenomena observed in the 17 th century by Christiaan Huygens. He found that two pendulum clocks placed on a common support synchronized over time. We study a model of this type of coupling primarily using the fourth-order Runge-Kutta method. We look at time series to get a picture of what types of synchronization occur and then once we figure out how to classify synchronization we study how varying the damping in the system affects the synchronization. We next look at what happens when driven pendulums replace the clocks. We compare phase portraits and bifurcation diagrams of the uncoupled driven pendulum to the coupled driven pendulums to get a picture of how the dynamics and chaotic tendencies of the driven pendulum change with the coupling.

  10. Fluid coupling in a discrete model of cochlear mechanics.

    PubMed

    Elliott, Stephen J; Lineton, Ben; Ni, Guangjian

    2011-09-01

    A discrete model of cochlear mechanics is introduced that includes a full, three-dimensional, description of fluid coupling. This formulation allows the fluid coupling and basilar membrane dynamics to be analyzed separately and then coupled together with a simple piece of linear algebra. The fluid coupling is initially analyzed using a wavenumber formulation and is separated into one component due to one-dimensional fluid coupling and one comprising all the other contributions. Using the theory of acoustic waves in a duct, however, these two components of the pressure can also be associated with a far field, due to the plane wave, and a near field, due to the evanescent, higher order, modes. The near field components are then seen as one of a number of sources of additional longitudinal coupling in the cochlea. The effects of non-uniformity and asymmetry in the fluid chamber areas can also be taken into account, to predict both the pressure difference between the chambers and the mean pressure. This allows the calculation, for example, of the effect of a short cochlear implant on the coupled response of the cochlea. PMID:21895085

  11. Analytic Thermoelectric Couple Modeling: Variable Material Properties and Transient Operation

    NASA Technical Reports Server (NTRS)

    Mackey, Jonathan A.; Sehirlioglu, Alp; Dynys, Fred

    2015-01-01

    To gain a deeper understanding of the operation of a thermoelectric couple a set of analytic solutions have been derived for a variable material property couple and a transient couple. Using an analytic approach, as opposed to commonly used numerical techniques, results in a set of useful design guidelines. These guidelines can serve as useful starting conditions for further numerical studies, or can serve as design rules for lab built couples. The analytic modeling considers two cases and accounts for 1) material properties which vary with temperature and 2) transient operation of a couple. The variable material property case was handled by means of an asymptotic expansion, which allows for insight into the influence of temperature dependence on different material properties. The variable property work demonstrated the important fact that materials with identical average Figure of Merits can lead to different conversion efficiencies due to temperature dependence of the properties. The transient couple was investigated through a Greens function approach; several transient boundary conditions were investigated. The transient work introduces several new design considerations which are not captured by the classic steady state analysis. The work helps to assist in designing couples for optimal performance, and also helps assist in material selection.

  12. First Analysis Of A Coupled Mediterranean - Atmosphere Model

    NASA Astrophysics Data System (ADS)

    Somot, S.; Sevault, F.; Béranger, K.; Déqué, M.; Crépon, M.

    A regional coupled ocean-atmosphere model has been developed to study the climate of the Mediterranean Region in a joint research between Météo-France-CNRM and CNRS-IPSL. This model is based on a variable resolution version of the global spectral AGCM Arpège-Climat with an horizontal grid mesh of 50 km over the mediterranean area and a limited area version of the OGCM OPA with an horizontal grid mesh of 10 km. The two models are coupled with the OASIS coupler developed by CERFACS. Outside the Mediterranean Sea, the sea surface temperature is prescribed from interannual observed data. A ten year coupled simulation has been done without relaxation nor correction. Sea- sonal averages as well as interannual variability have been compared with available observations and with uncoupled simulations.

  13. Initialization and Predictability of a Coupled ENSO Forecast Model

    NASA Technical Reports Server (NTRS)

    Chen, Dake; Zebiak, Stephen E.; Cane, Mark A.; Busalacchi, Antonio J.

    1997-01-01

    The skill of a coupled ocean-atmosphere model in predicting ENSO has recently been improved using a new initialization procedure in which initial conditions are obtained from the coupled model, nudged toward observations of wind stress. The previous procedure involved direct insertion of wind stress observations, ignoring model feedback from ocean to atmosphere. The success of the new scheme is attributed to its explicit consideration of ocean-atmosphere coupling and the associated reduction of "initialization shock" and random noise. The so-called spring predictability barrier is eliminated, suggesting that such a barrier is not intrinsic to the real climate system. Initial attempts to generalize the nudging procedure to include SST were not successful; possible explanations are offered. In all experiments forecast skill is found to be much higher for the 1980s than for the 1970s and 1990s, suggesting decadal variations in predictability.

  14. A Coupled Aeroelastic Model for Launch Vehicle Stability Analysis

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.

    2010-01-01

    A technique for incorporating distributed aerodynamic normal forces and aeroelastic coupling effects into a stability analysis model of a launch vehicle is presented. The formulation augments the linear state-space launch vehicle plant dynamics that are compactly derived as a system of coupled linear differential equations representing small angular and translational perturbations of the rigid body, nozzle, and sloshing propellant coupled with normal vibration of a set of orthogonal modes. The interaction of generalized forces due to aeroelastic coupling and thrust can be expressed as a set of augmenting non-diagonal stiffness and damping matrices in modal coordinates with no penalty on system order. While the eigenvalues of the structural response in the presence of thrust and aeroelastic forcing can be predicted at a given flight condition independent of the remaining degrees of freedom, the coupled model provides confidence in closed-loop stability in the presence of rigid-body, slosh, and actuator dynamics. Simulation results are presented that characterize the coupled dynamic response of the Ares I launch vehicle and the impact of aeroelasticity on control system stability margins.

  15. Coupling Efforts to the Accurate and Efficient Tsunami Modelling System

    NASA Astrophysics Data System (ADS)

    Son, S.

    2015-12-01

    In the present study, we couple two different types of tsunami models, i.e., nondispersive shallow water model of characteristic form(MOST ver.4) and dispersive Boussinesq model of non-characteristic form(Son et al. (2011)) in an attempt to improve modelling accuracy and efficiency. Since each model deals with different type of primary variables, additional care on matching boundary condition is required. Using an absorbing-generating boundary condition developed by Van Dongeren and Svendsen(1997), model coupling and integration is achieved. Characteristic variables(i.e., Riemann invariants) in MOST are converted to non-characteristic variables for Boussinesq solver without any loss of physical consistency. Established modelling system has been validated through typical test problems to realistic tsunami events. Simulated results reveal good performance of developed modelling system. Since coupled modelling system provides advantageous flexibility feature during implementation, great efficiencies and accuracies are expected to be gained through spot-focusing application of Boussinesq model inside the entire domain of tsunami propagation.

  16. Validation of coupled atmosphere-fire behavior models

    SciTech Connect

    Bossert, J.E.; Reisner, J.M.; Linn, R.R.; Winterkamp, J.L.; Schaub, R.; Riggan, P.J.

    1998-12-31

    Recent advances in numerical modeling and computer power have made it feasible to simulate the dynamical interaction and feedback between the heat and turbulence induced by wildfires and the local atmospheric wind and temperature fields. At Los Alamos National Laboratory, the authors have developed a modeling system that includes this interaction by coupling a high resolution atmospheric dynamics model, HIGRAD, with a fire behavior model, BEHAVE, to predict the spread of wildfires. The HIGRAD/BEHAVE model is run at very high resolution to properly resolve the fire/atmosphere interaction. At present, these coupled wildfire model simulations are computationally intensive. The additional complexity of these models require sophisticated methods for assuring their reliability in real world applications. With this in mind, a substantial part of the research effort is directed at model validation. Several instrumented prescribed fires have been conducted with multi-agency support and participation from chaparral, marsh, and scrub environments in coastal areas of Florida and inland California. In this paper, the authors first describe the data required to initialize the components of the wildfire modeling system. Then they present results from one of the Florida fires, and discuss a strategy for further testing and improvement of coupled weather/wildfire models.

  17. Effect of nonlinear nonlinear coupling to a pure dephasing model

    NASA Astrophysics Data System (ADS)

    Ge, Li; Zhao, Nan

    2015-03-01

    We investigate the influence of the nonlinear coupling to the coherence of a pure dephasing model. The total system consists of a qubit and a Bosonic bath, which are coupled by an interaction HI =g1σz ⊗ x +g2σz ⊗x2 with x =1/√{ 2} (a +a†) . It's shown that no matter how small g2 is, the long time behavior of the coherence is significantly changed by the nonlinear coupling for free induction decay (FID), while the effect of g1 can be neglected as long as g1 is much smaller than the enegy splitting of the qubit. In the case that many-pulse dynamical decoupling control is exerted on the qubit, g2 also modulates the oscillation of the coherence. Our results indicate that the nonlinear coupling must be taken into account for long time dynamics.

  18. Triple neutral gauge boson couplings in noncommutative Standard Model

    NASA Astrophysics Data System (ADS)

    Deshpande, N. G.; He, Xiao-Gang

    2002-05-01

    It has been shown recently that the triple neutral gauge boson couplings are not uniquely determined in noncommutative extension of the Standard Model (NCSM). Depending on specific schemes used, the couplings are different and may even be zero. To distinguish different realizations of the NCSM, additional information either from theoretical or experimental considerations is needed. In this Letter we show that these couplings can be uniquely determined from considerations of unification of electroweak and strong interactions. Using SU(5) as the underlying theory and integrating out the heavy degrees of freedom, we obtain unique non-zero new triple γγγ, γγZ, γZZ, ZZZ, γGG, ZGG and GGG couplings at the leading order in the NCSM. We also briefly discuss experimental implications.

  19. A coupled bubble plume-reservoir model for hypolimnetic oxygenation

    NASA Astrophysics Data System (ADS)

    Singleton, V. L.; Rueda, F. J.; Little, J. C.

    2010-12-01

    A model for a linear bubble plume used for hypolimnetic oxygenation was coupled with a three-dimensional hydrodynamic model to simulate the complex interaction between bubble plumes and the large-scale processes of transport and mixing. The coupled model accurately simulated the evolution of dissolved oxygen (DO) and temperature fields that occurred during two full-scale diffuser tests in a water supply reservoir. The prediction of asymmetric circulation cells laterally and longitudinally on both sides of the linear diffuser was due to the uneven reservoir bathymetry. Simulation of diffuser operation resulted in baroclinic pressure gradients, which caused vertical oscillations above the hypolimnion and contributed to distribution of plume detrainment upstream and downstream of the diffuser. On the basis of a first-order variance analysis, the largest source of uncertainty for both predicted DO and temperature was the model bathymetry, which accounted for about 90% of the overall uncertainty. Because the oxygen addition rate was 4 times the sediment oxygen uptake (SOU) rate, DO predictions were not sensitive to SOU. In addition to bathymetry, the momentum assigned to plume entrainment and detrainment is a significant source of uncertainty in the coupled model structure and appreciably affects the predicted intensity of mixing and lake circulation. For baseline runs, the entrainment and detrainment velocities were assumed to be half of the velocities through the flux face of the grid cells. Additional research on appropriate values of the plume detrainment momentum for the coupled model is required.

  20. A Fully Coupled Model for Electromechanics of the Heart

    PubMed Central

    Xia, Henian; Wong, Kwai; Zhao, Xiaopeng

    2012-01-01

    We present a fully coupled electromechanical model of the heart. The model integrates cardiac electrophysiology and cardiac mechanics through excitation-induced contraction and deformation-induced current. Numerical schemes based on finite element were implemented in a supercomputer. Numerical examples were presented using a thin cardiac tissue and a dog ventricle with realistic geometry. Performance of the parallel simulation scheme was studied. The model provides a useful tool to understand cardiovascular dynamics. PMID:23118801

  1. String coupling and interactions in type IIB matrix model

    SciTech Connect

    Kitazawa, Yoshihisa; Nagaoka, Satoshi

    2009-05-15

    We investigate the interactions of closed strings in a IIB matrix model. The basic interaction of the closed superstring is realized by the recombination of two intersecting strings. Such interaction is investigated in a IIB matrix model via two-dimensional noncommutative gauge theory in the IR limit. By estimating the probability of the recombination, we identify the string coupling g{sub s} in the IIB matrix model. We confirm that our identification is consistent with matrix string theory.

  2. Using Lateral Coupled Snakes for Modeling the Contours of Worms

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Ronneberger, Olaf; Schulze, Ekkehard; Baumeister, Ralf; Burkhardt, Hans

    A model called lateral coupled snakes is proposed to describe the contours of moving C. elegans worms on 2D images with high accuracy. The model comprises two curves with point correspondence between them. The line linking a corresponding pair is approximately perpendicular to the curves at the two points, which is ensured by shear restoring forces. Experimental proofs reveal that the model is a promising tool for locating and segmenting worms or objects with similar shapes.

  3. Revisiting ENSO Coupled Instability Theory and SST Error Growth in a Fully Coupled Model

    NASA Astrophysics Data System (ADS)

    Larson, S.; Kirtman, B. P.

    2015-12-01

    In an effort to untangle certain mechanisms contributing to the initiation of ENSO events, a coupled model framework is presented to isolate coupled instability induced SST error (or anomaly) growth in the ENSO region. The modeling framework using CCSM4 allows for seasonal ensembles of initialized simulations that are utilized to quantify the spatial and temporal behavior of coupled instabilities and the associated implications for ENSO predictability. The experimental design allows for unstable growth of initial perturbations that are not prescribed and several cases exhibit sufficiently rapid growth to produce ENSO events that do not require a previous ENSO event, large-scale wind trigger, or subsurface heat content precursor. Without these precursors, however, ENSO amplitude is reduced, suggesting that a combination of processes is essential to achieving peak amplitude in CCSM4. The results imply that even without classical precursors, including western Pacific "preconditioning," ENSO events can be excited via coupled instabilities in fully coupled models. By removing the subsurface heat content precursor, however, essentially a lower bounds for ENSO predictability in CCSM4 is established, although seasonal ensembles initialized later in the calendar year retain some predictability. The initial error growth exhibits strong seasonality with fastest growth during spring and summer and also dependence on the initialization month with fastest growth occurring in the July ensemble. The error growth displays a well-defined seasonal limit with ensembles initialized in the winter or spring exhibiting a clear seasonal halt in error growth around September, consistent with increased background stability typical during fall. Overall, dynamically driven error growth in CCSM4 is deemed best characterized by strong seasonality, dependence on the initialization month, and nonlinearity. The results pose real implications for predictability because the final error structure is

  4. Coupling Stokes and Darcy Flow in Melt Migration Modelling

    NASA Astrophysics Data System (ADS)

    Kaus, B.; Lehmann, R.; Lukáčová-Medvid'ová, M.

    2015-12-01

    Melt migration can be modelled by coupling variable-viscosity Stokes flow and Darcy flow. Stokes Flow, generally, captures the long-term behavior of the mantle and lithosphere while Darcy flow models the two-phase regime. The major unknowns of the coupled system are solid velocity, fluid pressure and compaction pressure, captured in the so-called three-field formulation of the system. The fluid velocity can be computed in a post-processing step. We present lithosperic-scale results of the fully-coupled system with visco-elasto-plastic rheologies. This comprises elasto-plastic effects from shearing (Mode II) as well as poro-elastic effects and "opening mode" (Mode I) tensile plasticity. The system is solved using the Finite Element Method on triangular or quadrilateral grids in the Matlab-based code MVEP. Triangular meshes are adapted dynamically to better resolve the different deformation modes (diapiric, channeling, diking).

  5. Thermosphere-ionosphere coupling - An experiment in interactive modeling

    NASA Technical Reports Server (NTRS)

    Forbes, Jeffrey M.; Roble, Raymond G.

    1990-01-01

    Using the NCAR thermosphere general circulation model, a series of controlled experiments is performed to investigate the interactive coupling between ionospheric plasma densities and thermospheric neutral winds. The interaction is accomplished by parameterizing the F layer peak height, h(m)F2, in an empirical ionospheric model in terms of the meridional wind, v(south), and by forcing the h(m)F2 and the v(south) parameters to remain mutually coupled in a dynamical calculation. It was found that mutual coupling between forcing and meridional wind is weak during the daytime when the F layer exhibits a broad vertical structure. At night, when the F2 layer is more localized, the neutral dynamical structure is dependent on whether forcing is significantly above or below the altitude (about 275-300 km) at which ion drag effectively competes with viscosity in the neutral momentum balance.

  6. Fast food consumption and food prices: evidence from panel data on 5th and 8th grade children.

    PubMed

    Khan, Tamkeen; Powell, Lisa M; Wada, Roy

    2012-01-01

    Fast food consumption is a dietary factor associated with higher prevalence of childhood obesity in the United States. The association between food prices and consumption of fast food among 5th and 8th graders was examined using individual-level random effects models utilizing consumption data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), price data from American Chamber of Commerce Researchers Association (ACCRA), and contextual outlet density data from Dun and Bradstreet (D&B). The results found that contextual factors including the price of fast food, median household income, and fast food restaurant outlet densities were significantly associated with fast food consumption patterns among this age group. Overall, a 10% increase in the price of fast food was associated with 5.7% lower frequency of weekly fast food consumption. These results suggest that public health policy pricing instruments such as taxes may be effective in reducing consumption of energy-dense foods and possibly reducing the prevalence of overweight and obesity among US children and young adolescents. PMID:22292115

  7. Fast Food Consumption and Food Prices: Evidence from Panel Data on 5th and 8th Grade Children

    PubMed Central

    Khan, Tamkeen; Powell, Lisa M.; Wada, Roy

    2012-01-01

    Fast food consumption is a dietary factor associated with higher prevalence of childhood obesity in the United States. The association between food prices and consumption of fast food among 5th and 8th graders was examined using individual-level random effects models utilizing consumption data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), price data from American Chamber of Commerce Researchers Association (ACCRA), and contextual outlet density data from Dun and Bradstreet (D&B). The results found that contextual factors including the price of fast food, median household income, and fast food restaurant outlet densities were significantly associated with fast food consumption patterns among this age group. Overall, a 10% increase in the price of fast food was associated with 5.7% lower frequency of weekly fast food consumption. These results suggest that public health policy pricing instruments such as taxes may be effective in reducing consumption of energy-dense foods and possibly reducing the prevalence of overweight and obesity among US children and young adolescents. PMID:22292115

  8. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Gonnenthal; N. Spyoher

    2001-02-05

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) 2000 [153447]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M and O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: (1) Performance Assessment (PA); (2) Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); (3) UZ Flow and Transport Process Model Report (PMR); and (4) Near-Field Environment (NFE) PMR. The work scope for this activity is presented in the TWPs cited above, and summarized as follows: continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in

  9. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    E. Sonnenthale

    2001-04-16

    The purpose of this Analysis/Model Report (AMR) is to document the Near-Field Environment (NFE) and Unsaturated Zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrologic-chemical (THC) processes on unsaturated zone flow and transport. This is in accordance with the ''Technical Work Plan (TWP) for Unsaturated Zone Flow and Transport Process Model Report'', Addendum D, Attachment D-4 (Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) 2000 [1534471]) and ''Technical Work Plan for Nearfield Environment Thermal Analyses and Testing'' (CRWMS M&O 2000 [153309]). These models include the Drift Scale Test (DST) THC Model and several THC seepage models. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal loading conditions, and predict the chemistry of waters and gases entering potential waste-emplacement drifts. The intended use of this AMR is to provide input for the following: Performance Assessment (PA); Near-Field Environment (NFE) PMR; Abstraction of Drift-Scale Coupled Processes AMR (ANL-NBS-HS-000029); and UZ Flow and Transport Process Model Report (PMR). The work scope for this activity is presented in the TWPs cited above, and summarized as follows: Continue development of the repository drift-scale THC seepage model used in support of the TSPA in-drift geochemical model; incorporate heterogeneous fracture property realizations; study sensitivity of results to changes in input data and mineral assemblage; validate the DST model by comparison with field data; perform simulations to predict mineral dissolution and precipitation and their effects on fracture properties and chemistry of water (but not flow rates) that may seep into drifts; submit modeling results to the TDMS and document the models. The model development, input data, sensitivity and validation studies described in this AMR are required

  10. Asymptotic behavior of coupled linear systems modeling suspension bridges

    NASA Astrophysics Data System (ADS)

    Dell'Oro, Filippo; Giorgi, Claudio; Pata, Vittorino

    2015-06-01

    We consider the coupled linear system describing the vibrations of a string-beam system related to the well-known Lazer-McKenna suspension bridge model. For ɛ > 0 and k > 0, the decay properties of the solution semigroup are discussed in dependence of the nonnegative parameters γ and h, which are responsible for the damping effects.

  11. Models of Excitation–Contraction Coupling in Cardiac Ventricular Myocytes

    PubMed Central

    Jafri, M. Saleet

    2012-01-01

    Excitation–contraction coupling describes the processes relating to electrical excitation through force generation and contraction in the heart. It occurs at multiple levels from the whole heart, to single myocytes and down to the sarcomere. A central process that links electrical excitation to contraction is calcium mobilization. Computational models that are well grounded in experimental data have been an effective tool to understand the complex dynamics of the processes involved in excitation–contraction coupling. Presented here is a summary of some computational models that have added to the understanding of the cellular and subcellular mechanisms that control ventricular myocyte calcium dynamics. Models of cardiac ventricular myocytes that have given insight into termination of calcium release and interval–force relations are discussed in this manuscript. Computational modeling of calcium sparks, the elementary events in cardiac excitation–contraction coupling, has given insight into mechanism governing their dynamics and termination as well as their role in excitation–contraction coupling and is described herein. PMID:22821602

  12. Spectra, triple, and quartic gauge couplings in a Higgsless model

    SciTech Connect

    Cheung Kingman; Wu Xiaohong; Yan Qishu

    2007-12-01

    Spectra, triple, and quartic gauge couplings of the Higgsless model with gauge group SU(2){sub L}xSU(2){sub R}xU(1){sub B-L} defined in warped space are explored with a numerical method. We extend the equation of motions, boundary conditions, and formalism of multi-gauge-boson vertices to the Hirn-Sanz scenario. By assuming the ideally delocalized fermion profile, we study the spectra of vector bosons as well as the triple and quartic gauge couplings among vector bosons. It is found that mass spectra can be greatly modified by the parameters of QCD power corrections. Meanwhile, the triple and quartic gauge couplings can deviate from the values of the standard model to at least {+-}10% and can saturate the LEP2 bounds. We find the triple gauge couplings of ZWW can be 50% smaller than the unitarity bounds. The triple gauge couplings of ZWW is 20% smaller than the unitarity bounds, which might challenge the detection of Z via s channel at LHC if m{sub Z}>500 GeV.

  13. An efficient model for coupling structural vibrations with acoustic radiation

    NASA Technical Reports Server (NTRS)

    Frendi, Abdelkader; Maestrello, Lucio; Ting, LU

    1993-01-01

    The scattering of an incident wave by a flexible panel is studied. The panel vibration is governed by the nonlinear plate equations while the loading on the panel, which is the pressure difference across the panel, depends on the reflected and transmitted waves. Two models are used to calculate this structural-acoustic interaction problem. One solves the three dimensional nonlinear Euler equations for the flow-field coupled with the plate equations (the fully coupled model). The second uses the linear wave equation for the acoustic field and expresses the load as a double integral involving the panel oscillation (the decoupled model). The panel oscillation governed by a system of integro-differential equations is solved numerically and the acoustic field is then defined by an explicit formula. Numerical results are obtained using the two models for linear and nonlinear panel vibrations. The predictions given by these two models are in good agreement but the computational time needed for the 'fully coupled model' is 60 times longer than that for 'the decoupled model'.

  14. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    SciTech Connect

    Munafò, A. Alfuhaid, S. A. Panesi, M.; Cambier, J.-L.

    2015-10-07

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.

  15. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    NASA Astrophysics Data System (ADS)

    Munafò, A.; Alfuhaid, S. A.; Cambier, J.-L.; Panesi, M.

    2015-10-01

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.

  16. Mutual coupling, channel model, and BER for curvilinear antenna arrays

    NASA Astrophysics Data System (ADS)

    Huang, Zhiyong

    This dissertation introduces a wireless communications system with an adaptive beam-former and investigates its performance with different antenna arrays. Mutual coupling, real antenna elements and channel models are included to examine the system performance. In a beamforming system, mutual coupling (MC) among the elements can significantly degrade the system performance. However, MC effects can be compensated if an accurate model of mutual coupling is available. A mutual coupling matrix model is utilized to compensate mutual coupling in the beamforming of a uniform circular array (UCA). Its performance is compared with other models in uplink and downlink beamforming scenarios. In addition, the predictions are compared with measurements and verified with results from full-wave simulations. In order to accurately investigate the minimum mean-square-error (MSE) of an adaptive array in MC, two different noise models, the environmental and the receiver noise, are modeled. The minimum MSEs with and without data domain MC compensation are analytically compared. The influence of mutual coupling on the convergence is also examined. In addition, the weight compensation method is proposed to attain the desired array pattern. Adaptive arrays with different geometries are implemented with the minimum MSE algorithm in the wireless communications system to combat interference at the same frequency. The bit-error-rate (BER) of systems with UCA, uniform rectangular array (URA) and UCA with center element are investigated in additive white Gaussian noise plus well-separated signals or random direction signals scenarios. The output SINR of an adaptive array with multiple interferers is analytically examined. The influence of the adaptive algorithm convergence on the BER is investigated. The UCA is then investigated in a narrowband Rician fading channel. The channel model is built and the space correlations are examined. The influence of the number of signal paths, number of the

  17. The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE)

    SciTech Connect

    Karen S. Browning; Marie Petrocek; Bonnie Bartel

    2006-06-01

    The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE) will be held June 8-12, 2005 at the University of Texas at Austin. Exciting new and ongoing discoveries show significant regulation of gene expression occurs after transcription. These post-transcriptional control events in plants range from subtle regulation of transcribed genes and phosphorylation, to the processes of gene regulation through small RNAs. This meeting will focus on the regulatory role of RNA, from transcription, through translation and finally degradation. The cross-disciplinary design of this meeting is necessary to encourage interactions between researchers that have a common interest in post-transcriptional gene expression in plants. By bringing together a diverse group of plant molecular biologist and biochemists at all careers stages from across the world, this meeting will bring about more rapid progress in understanding how plant genomes work and how genes are finely regulated by post-transcriptional processes to ultimately regulate cells.

  18. Need for Specific Sugar-Sweetened Beverage Lessons for 4th and 5th Graders

    PubMed Central

    Bea, Jennifer W.; Jacobs, Laurel; Waits, Juanita; Hartz, Vern; Martinez, Stephanie H.; Standfast, Rebecca D.; Farrell, Vanessa A.; Bawden, Margine; Whitmer, Evelyn; Misner, Scottie

    2015-01-01

    Objective Consumption of sugar-sweetened beverages (SSB) is linked to obesity. We hypothesized that school-based nutrition education would decrease SSB consumption. Design Self-selected interventional cohort with random selection for pre and post measurements Setting Arizona SNAP-Ed eligible schools Participants Randomly selected (9%) 4th and 5th grade classroom students Intervention The University of Arizona Nutrition Network (UANN) provided general nutrition education training and materials to teachers, to be delivered to their students. The UANN administered behavioral questionnaires to students in both Fall and Spring. Main Outcome Measure(s) Change in SSB consumption Analyses Descriptive statistics were computed for student demographics and beverage consumption on the day prior to testing. Paired t-tests evaluated change in classroom averages. Linear regression assessed potential correlates of SSB consumption. Results Fall mean SSB consumption was 1.1 (±0.2) times; mean milk and water intake were 1.6 (±0.2) and 5.2 (±0.7) times, respectively. Beverage consumption increased (3.2%) in springtime, with increased SSBs (14.4%) accounting for the majority (p=0.006). Change in SSB consumption was negatively associated with baseline SSB and water consumption, but positively associated with baseline milk fat (p≤0.05). Conclusions and Implications The results suggest the need for beverage specific education to encourage children to consume more healthful beverages in warmer weather. PMID:25239840

  19. Delay model for dynamically switching coupled RLC interconnects

    NASA Astrophysics Data System (ADS)

    Sharma, Devendra Kumar; Kaushik, Brajesh Kumar; Sharma, Rajender Kumar

    2014-04-01

    With the evolution of integrated circuit technology, the interconnect parasitics can be the limiting factor in high speed signal transmission. With increasing frequency of operation, length of interconnect and fast transition time of the signal, the RC models are not sufficient to estimate the delay accurately. To mitigate this problem, accurate delay models for coupled interconnects are very much required. This paper proposes an analytical model for estimating propagation delay in lossy coupled RLC interconnect lines for simultaneously switching scenario. To verify the proposed model, the analytical results are compared with those of FDTD and SPICE results for the two cases of inputs switching under consideration. An average error of 2.07% is observed which shows an excellent agreement with SPICE simulation and FDTD computations.

  20. Drift-Scale Coupled Processes (DST and THC Seepage) Models

    SciTech Connect

    P. Dixon

    2004-04-05

    The purpose of this Model Report (REV02) is to document the unsaturated zone (UZ) models used to evaluate the potential effects of coupled thermal-hydrological-chemical (THC) processes on UZ flow and transport. This Model Report has been developed in accordance with the ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]). The technical work plan (TWP) describes planning information pertaining to the technical scope, content, and management of this Model Report in Section 1.12, Work Package AUZM08, ''Coupled Effects on Flow and Seepage''. The plan for validation of the models documented in this Model Report is given in Attachment I, Model Validation Plans, Section I-3-4, of the TWP. Except for variations in acceptance criteria (Section 4.2), there were no deviations from this TWP. This report was developed in accordance with AP-SIII.10Q, ''Models''. This Model Report documents the THC Seepage Model and the Drift Scale Test (DST) THC Model. The THC Seepage Model is a drift-scale process model for predicting the composition of gas and water that could enter waste emplacement drifts and the effects of mineral alteration on flow in rocks surrounding drifts. The DST THC model is a drift-scale process model relying on the same conceptual model and much of the same input data (i.e., physical, hydrological, thermodynamic, and kinetic) as the THC Seepage Model. The DST THC Model is the primary method for validating the THC Seepage Model. The DST THC Model compares predicted water and gas compositions, as well as mineral alteration patterns, with observed data from the DST. These models provide the framework to evaluate THC coupled processes at the drift scale, predict flow and transport behavior for specified thermal-loading conditions, and predict the evolution of mineral alteration and fluid chemistry around potential waste emplacement drifts. The DST THC Model is used solely for the validation of the THC

  1. Coupled Climate Model Appraisal a Benchmark for Future Studies

    SciTech Connect

    Phillips, T J; AchutaRao, K; Bader, D; Covey, C; Doutriaux, C M; Fiorino, M; Gleckler, P J; Sperber, K R; Taylor, K E

    2005-08-22

    The Program for Climate Model Diagnosis and Intercomparison (PCMDI) has produced an extensive appraisal of simulations of present-day climate by eleven representative coupled ocean-atmosphere general circulation models (OAGCMs) which were developed during the period 1995-2002. Because projections of potential future global climate change are derived chiefly from OAGCMs, there is a continuing need to test the credibility of these predictions by evaluating model performance in simulating the historically observed climate. For example, such an evaluation is an integral part of the periodic assessments of climate change that are reported by the Intergovernmental Panel on Climate Change. The PCMDI appraisal thus provides a useful benchmark for future studies of this type. The appraisal mainly analyzed multi-decadal simulations of present-day climate by models that employed diverse representations of climate processes for atmosphere, ocean, sea ice, and land, as well as different techniques for coupling these components (see Table). The selected models were a subset of those entered in phase 2 of the Coupled Model Intercomparison Project (CMIP2, Covey et al. 2003). For these ''CMIP2+ models'', more atmospheric or oceanic variables were provided than the minimum requirements for participation in CMIP2. However, the appraisal only considered those climate variables that were supplied from most of the CMIP2+ models. The appraisal focused on three facets of the simulations of current global climate: (1) secular trends in simulation time series which would be indicative of a problematical ''coupled climate drift''; (2) comparisons of temporally averaged fields of simulated atmospheric and oceanic climate variables with available observational climatologies; and (3) correspondences between simulated and observed modes of climatic variability. Highlights of these climatic aspects manifested by different CMIP2+ simulations are briefly discussed here.

  2. Coupling Hydrologic and Hydrodynamic Models to Estimate PMF

    NASA Astrophysics Data System (ADS)

    Felder, G.; Weingartner, R.

    2015-12-01

    Most sophisticated probable maximum flood (PMF) estimations derive the PMF from the probable maximum precipitation (PMP) by applying deterministic hydrologic models calibrated with observed data. This method is based on the assumption that the hydrological system is stationary, meaning that the system behaviour during the calibration period or the calibration event is presumed to be the same as it is during the PMF. However, as soon as a catchment-specific threshold is reached, the system is no longer stationary. At or beyond this threshold, retention areas, new flow paths, and changing runoff processes can strongly affect downstream peak discharge. These effects can be accounted for by coupling hydrologic and hydrodynamic models, a technique that is particularly promising when the expected peak discharge may considerably exceed the observed maximum discharge. In such cases, the coupling of hydrologic and hydraulic models has the potential to significantly increase the physical plausibility of PMF estimations. This procedure ensures both that the estimated extreme peak discharge does not exceed the physical limit based on riverbed capacity and that the dampening effect of inundation processes on peak discharge is considered. Our study discusses the prospect of considering retention effects on PMF estimations by coupling hydrologic and hydrodynamic models. This method is tested by forcing PREVAH, a semi-distributed deterministic hydrological model, with randomly generated, physically plausible extreme precipitation patterns. The resulting hydrographs are then used to externally force the hydraulic model BASEMENT-ETH (riverbed in 1D, potential inundation areas in 2D). Finally, the PMF estimation results obtained using the coupled modelling approach are compared to the results obtained using ordinary hydrologic modelling.

  3. Sources of tropical Atlantic coupled model biases derived from initialised hindcasts and partially coupled sensitivity experiments

    NASA Astrophysics Data System (ADS)

    Deppenmeier, Anna-Lena; Hazeleger, Wilco; Haarsma, Rein; Prodhomme, Chloé; Exarchou, Eleftheria; Doblas-Reyes, Francisco J.

    2016-04-01

    State-of-the-art coupled general circulation models (CGCMs) still fail to simulate the mean state and variability of the tropical Atlantic (TA) climate correctly. We investigate the importance of air-sea interaction at different regions in the TA by means of performing partially coupled sensitivity experiments with the state-of-the-art CGCM EC-Earth3.1. All simulations are intialised from the observed climate state. By studying the initial drift in sensitivity experiments we obtain insight into the tropical dynamics and sources of model bias. We test the influence of realistic wind stress forcing over different regions of the TA on the development of SST as well as other oceanic biases. A series of hindcasts fully initialised in May and run until the end of August are performed with prescribed ERA-Interim zonal and meridional wind stresses over three different regions: firstly, we force the entire TA from 15N - 30S. Secondly, we force the equatorial band only between 5N - 5S, and finally we force the coastal area of the Angola Benguela upwelling region between 0W and the coast and between 5S - 30N. Our setup only affects the oceanic forcing and leaves the atmosphere free to adapt, such that we can identify the air-sea interaction processes in the different regions and their effect on the SST bias in the fully coupled system. The differences between forcing the entire TA and the equatorial region only are very small, which hints to the great importance of the relatively narrow equatorial region. The coastal upwelling area does not strongly affect the equatorial region in our model. We identify the equatorial band as most susceptible to errors in the wind stress forcing and, due to the strong atmosphere-ocean coupling, as source of the main biases in our model. The partially coupled experiments with initialised seasonal hindcasts appear to be a powerful tool to identify the sources of model biases and to identify relevant air-sea interaction processes in the TA.

  4. Theoretical Modeling of Mechanical-Electrical Coupling of Carbon Nanotubes

    SciTech Connect

    Lu, Jun-Qiang; Jiang, Hanqiang

    2008-01-01

    Carbon nanotubes have been studied extensively due to their unique properties, ranging from electrical, mechanical, optical, to thermal properties. The coupling between the electrical and mechanical properties of carbon nanotubes has emerged as a new field, which raises both interesting fundamental problems and huge application potentials. In this article, we will review our recently work on the theoretical modeling on mechanical-electrical coupling of carbon nanotubes subject to various loading conditions, including tension/compression, torsion, and squashing. Some related work by other groups will be also mentioned.

  5. A Coupled Wave-Current-Sediment model for Skagit Bay

    NASA Astrophysics Data System (ADS)

    Cowles, G. W.; Holmes, E. M.; Ralston, D. K.

    2010-12-01

    Along with tidal currents, waves provide a dominant forcing mechanism for sediment transport on many tidal flats. In semi-enclosed regions such as Skagit Bay, Washington, the wave action is due mainly to local wind forcing that occurs over seasonal and event scales. Due to the limited fetch, variations in along-flat wave characteristics can drive gradients in the wave-induced bottom stress and resulting sediment transport. In this work, we use an unstructured grid, coupled wave-current-sediment model to study the influence of wave-induced near bottom stresses in the presence of tidal currents on the sediment transport within the Skagit River delta and Skagit Bay. The coupled model consists of three primary components: the Finite Volume Coastal Ocean Model (FVCOM) for hydrodynamics, the unstructured grid model SWAN to compute the phase-averaged wave field, and the Community Sediment Transport Modeling System. Model sensitivities to the choice of coupling and bottom boundary layer formulations are examined. Results from process oriented simulations will be presented. The process studies use a realistic domain with controlled forcing conditions to quantify the influence of wave-induced bed stresses on the sediment dynamics in Skagit Bay.

  6. Climate Change and Groundwater: A Coupling of Models

    NASA Astrophysics Data System (ADS)

    Chesebrough, E.; Gorokhovich, Y.

    2012-12-01

    Groundwater is the largest source of readily available freshwater on our planet. Aquifers are vulnerable to climate change and require new groundwater management plans to account for changing precipitation patterns and sea level rise, among other factors. Atmospheric General Circulation Models (GCMs) use algorithms applied to historic and modern data to simulate current climatic conditions and predict future changes on a global scale. However, these GCMs are limited in their application at a regional level, thus making hydrogeological predictions difficult. Models designed specifically for hydrogeology are most commonly designed for regional assessment, and they can incorporate GCM outputs. Some of the challenges in coupling GCM outputs and hydrogeological models are the differences in spatial and temporal scales. In addition, the different scenarios of climate response to Greenhouse Gas forcings create a range of outputs from GCMs, affecting the predicting capacity of hydrogeological models. The use of dynamic and statistical downscaling of GCMs make it possible to overcome these challenges by taking the climate simulation output from GCMs and incorporating it as the input for hydrogeological models. This coupling of GCMs to groundwater models makes new groundwater management plans possible, which will ensure the sustainability of these resources in the future. The studies referenced within this paper highlight the advantages and disadvantages of various combinations of coupling and downscaling methodologies.

  7. A dynamical stochastic coupled model for financial markets

    NASA Astrophysics Data System (ADS)

    Govindan, T. E.; Ibarra-Valdez, Carlos; Ruiz de Chávez, J.

    2007-07-01

    A model coupling a deterministic dynamical system which represents trading, with a stochastic one that represents asset prices evolution is presented. Both parts of the model have connections with well established dynamic models in mathematical economics and finance. The main objective is to represent the double feedback between trading dynamics (the demand/supply interaction) and price dynamics (assumed as largely random). We present the model, and address to some extent existence and uniqueness, continuity with respect to initial conditions and stability of solutions. The non-Lipschitz case is briefly considered as well.

  8. A neural mass model of phase-amplitude coupling.

    PubMed

    Chehelcheraghi, Mojtaba; Nakatani, Chie; Steur, Erik; van Leeuwen, Cees

    2016-06-01

    Brain activity shows phase-amplitude coupling between its slow and fast oscillatory components. We study phase-amplitude coupling as recorded at individual sites, using a modified version of the well-known Wendling neural mass model. To the population of fast inhibitory interneurons of this model, we added external modulatory input and dynamic self-feedback. These two modifications together are sufficient to let the inhibitory population serve as a limit-cycle oscillator, with frequency characteristics comparable to the beta and gamma bands. The frequency and power of these oscillations can be tuned through the time constant of the dynamic and modulatory input. Alpha band activity is generated, as is usual in such models, as a result of interactions of pyramidal neurons and a population of slow inhibitory interneurons. The slow inhibitory population activity directly influences the fast oscillations via the synaptic gain between slow and fast inhibitory populations. As a result, the amplitude envelope of the fast oscillation is coupled to the phase of the slow activity; this result is consistent with the notion that phase-amplitude coupling is effectuated by interactions between inhibitory interneurons. PMID:27241189

  9. A bidirectional coupling procedure applied to multiscale respiratory modeling

    NASA Astrophysics Data System (ADS)

    Kuprat, A. P.; Kabilan, S.; Carson, J. P.; Corley, R. A.; Einstein, D. R.

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFDs) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the modified Newton's method with nonlinear Krylov accelerator developed by Carlson and Miller [1], Miller [2] and Scott and Fenves [3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a "pressure-drop" residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD-ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural

  10. A Bidirectional Coupling Procedure Applied to Multiscale Respiratory Modeling.

    PubMed

    Kuprat, A P; Kabilan, S; Carson, J P; Corley, R A; Einstein, D R

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFD) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the Modified Newton's Method with nonlinear Krylov accelerator developed by Carlson and Miller [1, 2, 3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a "pressure-drop" residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD-ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural pressure applied to the multiple sets

  11. A Bidirectional Coupling Procedure Applied to Multiscale Respiratory Modeling

    SciTech Connect

    Kuprat, Andrew P.; Kabilan, Senthil; Carson, James P.; Corley, Richard A.; Einstein, Daniel R.

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFD) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the Modified Newton’s Method with nonlinear Krylov accelerator developed by Carlson and Miller [1, 2, 3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD-ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural pressure applied to the multiple

  12. A bidirectional coupling procedure applied to multiscale respiratory modeling

    SciTech Connect

    Kuprat, A.P.; Kabilan, S.; Carson, J.P.; Corley, R.A.; Einstein, D.R.

    2013-07-01

    In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFDs) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the modified Newton’s method with nonlinear Krylov accelerator developed by Carlson and Miller [1], Miller [2] and Scott and Fenves [3]. Our extensions include the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a “pressure-drop” residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lower-dimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. The lower-dimensional models that are considered in this study are sets of simple ordinary differential equations (ODEs) representing the compliant mechanics of symmetric human pulmonary airway trees. To validate the method, we compare the predictions of hybrid CFD–ODE models against an ODE-only model of pulmonary airflow in an idealized geometry. Subsequently, we couple multiple sets of ODEs describing the distal lung to an imaging-based human lung geometry. Boundary conditions in these models consist of atmospheric pressure at the mouth and intrapleural

  13. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  14. A Coupled General Circulation Model of the Archean Earth

    NASA Astrophysics Data System (ADS)

    Wolf, E. T.; Toon, O. B.

    2011-12-01

    We present results from a new coupled general circulation model suitable for deep paleoclimate studies. Particular interest is given to the faint young Sun paradox. The model is based on the Community Earth System Model maintained by the National Center for Atmospheric Research [1]. Prognostic atmosphere, ocean, land, ice, and hydrological cycle models are coupled. A new correlated-k radiative transfer model has been implemented allowing accurate flux calculations for anoxic atmospheres containing high concentrations of CO2 and CH4 [2, 3]. This model represents a significant improvement upon one-dimensional radiative-convective climate models used previously to study ancient climate [4]. Cloud and ice albedo feedbacks will be accurately quantified and new constraints on Archean surface temperatures will be revealed. References [1] Collins W.D. et al. "Description of the NCAR Community Atmosphere Model (CAM 3.0)." NCAR Technical Note, 2004. [2] Toon O.B., McKay, C.P., Ackerman, T.P. "Rapid Calculation of Radiative Heating Rates and Photodissociation Rates in Inhomogeneous Multiple Scattering Atmospheres." J. Geo. Res., 94(D13), 16287 - 16301, 1989. [3] Mlawer, E.J., et al. "Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave." J. Geo. Res., 102(D14), 16663 - 16682, 1997. [4] Kasting J.F., Pollack, J.B., Crisp, D. "Effects of High CO2 Levels on Surface Temperature and Atmospheric Oxidation State of the Early Earth." J. Atm. Chem., 1, 403-428, 1984.

  15. Implementing SPRINTT [Student Polar Research with IPY National(and International)Teacher Training] in 5th Grade Science

    NASA Astrophysics Data System (ADS)

    Glass, D. S.

    2009-12-01

    I implemented the new NSF-funded SPRINTT (Student Polar Research with IPY National (and International) Teacher Training) curriculum with a 5th grade science class. SPRINTT, developed at U.S. Satellite Laboratory, Inc., is a 5-8 week science program teaching 5th through 10th graders to investigate climate change using polar data. The program includes perspectives of both Western scientists and the indigenous Northern population. The course contains three phases: Phase 1 includes content, data interpretation, and hands-on experiments to study Frozen Water, Frozen Land, and Food; Phase 2 (optional) includes further content on specific polar topics; and Phase 3 is a scaffolded research investigation. Before the course, teachers were trained via live webinars. This curriculum capitalizes on children’s innate fascination with our planet’s final frontier and combines it with the politically and scientifically relevant topic of climate change. In 2009, I used SPRINTT with 23 heterogeneous fifth grade students at National Presbyterian School in Washington DC for an environmental science unit. Overall, it was a success. The students met most of the learning objectives and showed enthusiasm for the material. I share my experiences to help other educators and curriculum developers. The Phase 1 course includes earth science (glaciers, sea ice, weather and climate, greenhouse gases, seasons, and human impacts on environments), life science (needs of living things, food and energy transfer, adaptations, and ecosystems and biomes) and physical science (phases of matter). Tailoring the program, I focused on Phase 1, the most accessible material and content, while deemphasizing the more cumbersome Phase 3 online research project. Pre-assessments documented the students’ misconceptions and informed instruction. The investigations were appropriately educational and interesting. For example, students enjoyed looking at environmental factors and their impact on the people in the

  16. 5th International conference on Physics and Astrophysics of Quark Gluon Plasma

    NASA Astrophysics Data System (ADS)

    Sinha, Bikash; Alam, Jan-E.; Nayak, Tapan K.

    2006-11-01

    The 5th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP 2005) was held on 8 - 12 February 2005 at the Variable Energy Cyclotron Centre and Saha Institute of Nuclear Physics campus, Kolkata, India. The conference was enriched by the august presence of about 300 participants representing 18 countries across the globe. It had plenary talks and oral presentations, which form a part of these proceedings. Besides invited and contributed talks there were also a large number of poster presentations. The conference was energized by discussions of fresh experimental data from RHIC on strong elliptic flow, jet quenching, single photon spectra etc. Moreover, new theoretical results were brought to the discussion forum during this conference. Colour glass condensates, hydrodynamical flow, jet quenching and sQGP were intensely debated by the participants. The highlight of ICPAQGP 2005 was the presentation of fresh experimental results from the RHIC-IV run. The ICPAQGP series, since its inception in 1988, has placed emphasis on the role of quark matter in the fields of astrophysics and cosmology. The subsequent conferences held in 1993, 1997, 2001 and 2005 had also retained this focus. The conference was preceded by a Fest Colloquium in honour of Professor Bikash Sinha. Professor Sinha, regarded as the pioneer in establishing quark gluon plasma research in India, has successfully encouraged a group of young Indian researchers to devote themselves wholeheartedly to QGP research - both theoretical and experimental. Members of the International Advisory Committee played a pivotal role mainly in the selection of speakers. The contributions of the Organizing Committee in all aspects, from selecting the contributory talks posters down to arranging local hospitality, were much appreciated. We thank the members of both committees for making ICPAQGP 2005 an interesting platform for scientific deliberation. The ICPAQGP 2005 was supported financially by

  17. Black sea surface temperature anomaly on 5th August 1998 and the ozone layer thickness

    NASA Astrophysics Data System (ADS)

    Manev, A.; Palazov, K.; Raykov, St.; Ivanov, V.

    2003-04-01

    BLACK SEA SURFACE TEMPERATURE ANOMALY ON 5th AUGUST 1998 AND THE OZONE LAYER THICKNESS A. Manev , K. Palazov , St. Raykov, V. Ivanov Solar Terrestrial Influences Laboratory, Bulgarian Academy of Sciences amanev@abv.bg This paper focuses on the peculiarities of the Black Sea surface temperature anomaly on 05.08.1998. Researching the daily temperature changes in a number of control fields in the course of 8-10 years, we have found hidden correlations and anomalous deviations in the sea surface temperatures on a global scale. Research proves the statistical reliability of the temperature anomaly on the entire Black Sea surface registered on 04.-05.08.1998. In the course of six days around these dates the temperatures are up to 2°C higher than the maximum temperatures in this period in the other seven years. A more detailed analysis of the dynamics of the anomaly required the investigation of five Black Sea surface characteristic zones of 75x75 km. The analysis covers the period 20 days - 10 days before and 10 days after the anomaly. Investigations aimed at interpreting the reasons for the anomalous heating of the surface waters. We have tried to analyze the correlation between sea surface temperature and the global ozone above the Black Sea by using simultaneously data from the two satellite systems NOAA and TOMS. Methods of processing and comparing the data from the two satellite systems are described. The correlation coefficients values for the five characteristic zones are very high and close, which proves that the character of the correlation ozone - sea surface temperature is the same for the entire Black Sea surface. Despite the high correlation coefficient, we have proved that causality between the two phenomena at the time of the anomaly does not exit.

  18. Patterns of Irregular Burials in Western Europe (1st-5th Century A.D.)

    PubMed Central

    Milella, Marco; Mariotti, Valentina; Belcastro, Maria Giovanna; Knüsel, Christopher J.

    2015-01-01

    Background Irregular burials (IB—burials showing features that contrast with the majority of others in their geographic and chronological context) have been the focus of archaeological study because of their relative rarity and enigmatic appearance. Interpretations of IB often refer to supposed fear of the dead or to social processes taking place in time-specific contexts. However, a comprehensive and quantitative analysis of IB for various geographical contexts is still lacking, a fact that hampers any discussion of these burials on a larger scale. Methods Here, we collected a bibliographic dataset of 375 IB from both Britain and Continental Europe, altogether spanning a time period from the 1st to the 5th century AD. Each burial has been coded according to ten dichotomous variables, further analyzed by means of chi-squared tests on absolute frequencies, non-metric multidimensional scaling, and cluster analysis. Results Even acknowledging the limits of this study, and in particular the bias represented by the available literature, our results point to interesting patterns. Geographically, IB show a contrast between Britain and Continental Europe, possibly related to historical processes specific to these regions. Different types of IB (especially prone depositions and depositions with the cephalic extremity displaced) present a series of characteristics and associations between features that permit a more detailed conceptualization of these occurrences from a socio-cultural perspective that aids to elucidate their funerary meaning. Conclusions and Significance Altogether, the present work stresses the variability of IB, and the need to contextualize them in a proper archaeological and historical context. It contributes to the discussion of IB by providing a specific geographic and chronological frame of reference that supports a series of hypotheses about the cultural processes possibly underlying their occurrence. PMID:26115408

  19. Pathological gambling and couple: towards an integrative systemic model.

    PubMed

    Cunha, Diana; Relvas, Ana Paula

    2014-06-01

    This article is a critical literature review of pathological gambling focused in the family factors, particularly in the couple dynamics. Its main goal is to develop an explicative integrative systemic model of pathological gambling, based in these couple dynamics. To achieve that aim, a bibliography search was made, using on-line data bases (e.g., EBSCO Host) and recognized books in pathological gambling subject, as well as in the systemic approach in general. This process privileged the recent works (about 70 % of the reviewed literature was published in the last decade), however, also considered some classic works (the oldest one dates back to 1970). The guiding focus of this literature search evolves according to the following steps: (1) search of general comprehension of pathological gambling (19 references), (2) search specification to the subject "pathological gambling and family" (24 references), (3) search specification to the subject "pathological gambling and couple"(11 references), (4) search of systemic information which integrates the evidence resulted in the previous steps (4 references). The developed model is constituted by different levels of systemic complexity (social context, family of origin, couple and individual) and explains the problem as a signal of perturbation in the marital subsystem vital functions (e.g., power and control) though the regularities of marital dynamics of pathological gamblers. Furthermore, it gives theoretical evidence of the systemic familiar intervention in the pathological gambling. PMID:23423730

  20. Coupled surface-water and ground-water model

    USGS Publications Warehouse

    Swain, Eric D.; Wexler, Eliezer J.

    1991-01-01

    In areas with dynamic and hydraulically well connected ground-water and surface-water systems, it is desirable that stream-aquifer interaction be simulated with models of equal sophistication and accuracy. Accordingly, a new, coupled ground-water and surface-water model was developed by combining the U.S. Geological Survey models MODFLOW and BRANCH. MODFLOW is the widely used modular three-dimensional, finite-difference, ground-water model and BRANCH is a one-dimensional numerical model commonly used to simulate flow in open-channel networks. Because time steps used in ground-water modeling commonly are much longer than those used in surface-water simulations, provision has been made for handling multiple BRANCH time steps within one MODFLOW time step. Verification testing of the coupled model was done using data from previous studies and by comparing results with output from a simpler four-point implicit open-channel flow model linked with MODFLOW.

  1. Coupled vibro-acoustic model updating using frequency response functions

    NASA Astrophysics Data System (ADS)

    Nehete, D. V.; Modak, S. V.; Gupta, K.

    2016-03-01

    Interior noise in cavities of motorized vehicles is of increasing significance due to the lightweight design of these structures. Accurate coupled vibro-acoustic FE models of such cavities are required so as to allow a reliable design and analysis. It is, however, experienced that the vibro-acoustic predictions using these models do not often correlate acceptably well with the experimental measurements and hence require model updating. Both the structural and the acoustic parameters addressing the stiffness as well as the damping modeling inaccuracies need to be considered simultaneously in the model updating framework in order to obtain an accurate estimate of these parameters. It is also noted that the acoustic absorption properties are generally frequency dependent. This makes use of modal data based methods for updating vibro-acoustic FE models difficult. In view of this, the present paper proposes a method based on vibro-acoustic frequency response functions that allow updating of a coupled FE model by considering simultaneously the parameters associated with both the structural as well as the acoustic model of the cavity. The effectiveness of the proposed method is demonstrated through numerical studies on a 3D rectangular box cavity with a flexible plate. Updating parameters related to the material property, stiffness of joints between the plate and the rectangular cavity and the properties of absorbing surfaces of the acoustic cavity are considered. The robustness of the method under presence of noise is also studied.

  2. Nonrelativistic approaches derived from point-coupling relativistic models

    SciTech Connect

    Lourenco, O.; Dutra, M.; Delfino, A.; Sa Martins, J. S.

    2010-03-15

    We construct nonrelativistic versions of relativistic nonlinear hadronic point-coupling models, based on new normalized spinor wave functions after small component reduction. These expansions give us energy density functionals that can be compared to their relativistic counterparts. We show that the agreement between the nonrelativistic limit approach and the Skyrme parametrizations becomes strongly dependent on the incompressibility of each model. We also show that the particular case A=B=0 (Walecka model) leads to the same energy density functional of the Skyrme parametrizations SV and ZR2, while the truncation scheme, up to order {rho}{sup 3}, leads to parametrizations for which {sigma}=1.

  3. MOUNTAIN-SCALE COUPLED PROCESSES (TH/THC/THM)MODELS

    SciTech Connect

    Y.S. Wu

    2005-08-24

    This report documents the development and validation of the mountain-scale thermal-hydrologic (TH), thermal-hydrologic-chemical (THC), and thermal-hydrologic-mechanical (THM) models. These models provide technical support for screening of features, events, and processes (FEPs) related to the effects of coupled TH/THC/THM processes on mountain-scale unsaturated zone (UZ) and saturated zone (SZ) flow at Yucca Mountain, Nevada (BSC 2005 [DIRS 174842], Section 2.1.1.1). The purpose and validation criteria for these models are specified in ''Technical Work Plan for: Near-Field Environment and Transport: Coupled Processes (Mountain-Scale TH/THC/THM, Drift-Scale THC Seepage, and Drift-Scale Abstraction) Model Report Integration'' (BSC 2005 [DIRS 174842]). Model results are used to support exclusion of certain FEPs from the total system performance assessment for the license application (TSPA-LA) model on the basis of low consequence, consistent with the requirements of 10 CFR 63.342 [DIRS 173273]. Outputs from this report are not direct feeds to the TSPA-LA. All the FEPs related to the effects of coupled TH/THC/THM processes on mountain-scale UZ and SZ flow are discussed in Sections 6 and 7 of this report. The mountain-scale coupled TH/THC/THM processes models numerically simulate the impact of nuclear waste heat release on the natural hydrogeological system, including a representation of heat-driven processes occurring in the far field. The mountain-scale TH simulations provide predictions for thermally affected liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature (together called the flow fields). The main focus of the TH model is to predict the changes in water flux driven by evaporation/condensation processes, and drainage between drifts. The TH model captures mountain-scale three-dimensional flow effects, including lateral diversion and mountain-scale flow patterns. The mountain-scale THC model evaluates TH effects on water and gas

  4. Modeling Reactive Transport in Coupled Groundwater-Conduit Systems

    NASA Astrophysics Data System (ADS)

    Spiessl, S. M.; Sauter, M.; Zheng, C.; Viswanathan, H. S.

    2002-05-01

    Modeling reactive transport in coupled groundwater-conduit systems requires consideration of two transport time scales in the flow and transport models. Consider for example a subsurface mine consisting of a network of highly conductive shafts, drifts or ventilation raises (i.e., conduits) within the considerably less permeable ore material (i.e., matrix). In the conduits, potential contaminants can travel much more rapidly than in the background aquifer (matrix). Since conduits cannot necessarily be regarded as a continuum, double continuum models are only of limited use for simulation of contaminant transport in such coupled groundwater-conduit systems. This study utilizes a "hybrid" flow and transport model in which contaminants can in essence be transported at a slower time scale in the matrix and at a faster time scale in the conduits. The hybrid flow model uses an approach developed by Clemens et al. (1996), which is based on the modelling of flow in a discrete pipe network, coupled to a continuum representing the low-permeability inter-conduit matrix blocks. Laminar or turbulent flow can be simulated in the different pipes depending on the flow conditions in the model domain. The three-dimensional finite-difference groundwater flow model MODFLOW (Harbaugh and McDonald, 1996) is used to simulate flow in the continuum. Contaminant transport within the matrix is simulated with a continuum approach using the three-dimensional multi-species solute transport model MT3DMS (Zheng and Wang, 1999), while that in the conduit system is simulated with a one-dimensional advective transport model. As a first step for reactive transport modeling in such systems, only equilibrium reactions among multiple species are considered by coupling the hybrid transport model to a geochemical speciation package. An idealized mine network developed by Viswanathan and Sauter (2001) is used as a test problem in this study. The numerical experiment is based on reference date collected from

  5. Coupled Hydrological and Hydraulic Modeling for Flood Mapping

    NASA Astrophysics Data System (ADS)

    Drobot, Radu; Draghia, Aurelian

    2014-05-01

    The delineation of the flooded areas involves both hydrological and hydraulic modeling. Usually, the hydrological and hydraulic processes are separately treated. In the proposed methodology, the coupled modeling of the hydrological and hydraulic processes is used. The calibration and validation of the hydrological parameters is undertaken based on historical floods using the corresponding precipitations for the same period. The calibration process was more complicated in the presence of reservoirs, when not only the discharges downstream but also the water level in the reservoirs had to be accurately reproduced. The time step for precipitation is 1 hour, corresponding to the concentration time of the smallest catchments. The maximum annual precipitation for different time steps (1; 3; 6; 24 hours) were statistically processed and based on these results the cumulative rainfall curves and the synthetic hyetographs were derived. The rainfall duration is depending on the concentration time. Mike 11 with UHM module based on SCS model was used for coupled hydrological and hydraulic modeling. The coupled hydrological and hydraulic simulation for the scaled precipitation leads both at the computation of the components which contribute to the generation of the P% flood at the Hydrometric stations as well as to the determination of the discharge hydrograph along the main river. Based on these results the flood hazard maps were obtained using a DTM based on Lidar data. The methodology was applied for a river basin in Romania of 12500 km2.

  6. Coupled land-atmosphere modeling of methane emissions with WRF

    NASA Astrophysics Data System (ADS)

    Taylor, D.

    2013-12-01

    This project aims to couple a soil model for methane transport to an atmospheric model to predict methane emissions and dispersion. Methane is a potent greenhouse gas, 20 times as efficient at trapping heat in the atmosphere as the most prevalent greenhouse gas, carbon dioxide. It has been estimated that 60% of methane emissions in the earth's atmosphere come from anthropogenic sources, 17% of which comes from landfills, making landfills the third largest contributor of human-generated methane. Due to high costs and non-ideal weather conditions, field measurements of methane concentration at landfills are difficult and infrequent, so estimates of annual emissions from landfills are not very accurate. We plan to create a coupled land-atmosphere model that takes production and oxidation of methane into account when calculating methane emissions. This model will give a better understanding of how much methane is emitted annually from a given landfill and assist with monitoring efforts. It will also demonstrate the magnitude of diurnal and seasonal variations in methane emissions, which may identify errors in yearly methane emissions estimates made by extrapolating from a small number of field measurements. As a first step, an existing land-surface model, Noah, is modified to compute the transport of oxygen and methane along a 1-D soil column. Surface emissions are calculated using a gradient flux method with a boundary layer conductance that depends on the wind speed. These modifications to the land-surface model will be added to the Weather Research and Forecasting model to predict atmospheric dispersion of methane emitted by landfills. Comparisons to observations are made at two different landfill sites to validate the coupled model.

  7. Nao/ao Variability In The Coupled Bergen Climate Model

    NASA Astrophysics Data System (ADS)

    Sorteberg, A.; Furevik, T.; Bentsen, M.; Drange, H.; Kvamsto, N. G.; Thorstensen-Kindem, I.

    A new fully coupled atmosphere-ocean-sea ice model, known as the Bergen Climate Model (BCM), has been developed. The coupled model can be run with stretched co- ordinates both in the atmosphere and ocean and consists of the atmospheric model ARPEGE/IFS, and a global version of the isopycnal ocean model MICOM, including a sea ice model. The atmospheric model ARPEGE/IFS (c22) is a spectral model devel- oped jointly by Meteo-France and the European Centre for Medium-Range Weather Forecasts (ECMWF). The ocean circulation model is the Miami Isopycnic Coordinate Ocean Model (MI- COM). Several modifications have been done to the MICOM model including the incorporation of a thermodynamic and dynamic sea ice model, the use of tempera- ture as a prognostic variable instead of salinity, and the use of a metric scale factor in both lateral, so the model can easily be configured on a general orthogonal grid. Also,the thickness diffusion has been modified to better handle diffusion near bottom topography and the base of the mixed layer. Coupling has been done with the library OASIS where 14 different fields are ex- changed using Montecarlo mapping and subgrid interpolation. Continental runoff into the correct rivers and discharge into the correct ocean grid cells are performed using the Total Runoff Integrating Pathways (TRIP) data set. Results will be present from a 300 years flux adjusted control integration of BCM with todays climate, using a unstretched T63 truncation in the atmosphere and a 0.8 by 2.4 degree resolution (near the equator gradually transforming to approximate square grid cells towards the poles) in the ocean. The model output has been analysed for large scale variability in both the ocean and atmosphere, with emphasise on the North Atlantic and Arctic climate. Statistical properties of the NAO/AO signal, and its im- pacts on the climate components, are identified and compared with observations. The NAO/AO mode of variability show up in the model with

  8. Assessing groundwater policy with coupled economic-groundwater hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Mulligan, Kevin B.; Brown, Casey; Yang, Yi-Chen E.; Ahlfeld, David P.

    2014-03-01

    This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi-Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self-interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single-cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.

  9. Robust Validation of ENSO in IPCC-Class Coupled Models

    NASA Astrophysics Data System (ADS)

    Stevenson, Samantha; Fox-Kemper, Baylor; Jochum, Markus

    2010-05-01

    Wavelet probability analysis, a new method of model validation, is used to assess the performance of ENSO in a variety of coupled climate models. Wavelet probability analysis relies on wavelet spectra for a given time series, for which the amount of spectral overlap between subsets is measured using a quantity known as the wavelet probability index (WPI). This approach provides quantitative estimates of model agreement relative to either observations or other models, accompanied by well-defined confidence levels. ENSO, as represented by the NINO3.4 index, has been examined in 2,000 year long coupled integrations of both the new NCAR CCSM3.5 and GFDL's CM2.1; interestingly, it is not possible to distinguish either model from observations of NINO3.4 during 1949-2003, for runs shorter than 200 years. At longer model run lengths, some inaccuracies are seen in both CCSM3.5 and CM2.1 relative to observations. CCSM3.5 and CM2.1 are compared to one another using hypothesis testing procedures, and changes in model physics discussed in terms of their impact on ENSO. Finally, the method is applied to non-equilibrium simulations, using both high-CO2 'ramp-up' runs and selected IPCC AR4 integrations. This allows the effect of changing CO2 levels on ENSO activity to be examined, and the statistical significance of such effects to be determined.

  10. A parallel coupled oceanic-atmospheric general circulation model

    SciTech Connect

    Wehner, M.F.; Bourgeois, A.J.; Eltgroth, P.G.; Duffy, P.B.; Dannevik, W.P.

    1994-12-01

    The Climate Systems Modeling group at LLNL has developed a portable coupled oceanic-atmospheric general circulation model suitable for use on a variety of massively parallel (MPP) computers of the multiple instruction, multiple data (MIMD) class. The model is composed of parallel versions of the UCLA atmospheric general circulation model, the GFDL modular ocean model (MOM) and a dynamic sea ice model based on the Hiber formulation extracted from the OPYC ocean model. The strategy to achieve parallelism is twofold. One level of parallelism is accomplished by applying two dimensional domain decomposition techniques to each of the three constituent submodels. A second level of parallelism is attained by a concurrent execution of AGCM and OGCM/sea ice components on separate sets of processors. For this functional decomposition scheme, a flux coupling module has been written to calculate the heat, moisture and momentum fluxes independent of either the AGCM or the OGCM modules. The flux coupler`s other roles are to facilitate the transfer of data between subsystem components and processors via message passing techniques and to interpolate and aggregate between the possibly incommensurate meshes.

  11. Modeling of a bipedal robot using mutually coupled Rayleigh oscillators.

    PubMed

    Filho, Armando C de Pina; Dutra, Max S; Raptopoulos, Luciano S C

    2005-01-01

    The objective of the work presented here was the modeling of a bipedal robot using a central pattern generator (CPG) formed by a set of mutually coupled Rayleigh oscillators. We analyzed a 2D model, with the three most important determinants of gait, that performs only motions parallel to the sagittal plane. Using oscillators with integer relation of frequency, we determined the transient motion and the stable limit cycles of the network formed by the three oscillators, showing the behavior of the knee angles and the hip angle. A comparison of the plotted graphs revealed that the system provided excellent results when compared to experimental analysis. Based on the results of the study, we come to the conclusion that the use of mutually coupled Rayleigh oscillators can represent an excellent method of signal generation, allowing their application for feedback control of a walking machine. PMID:15580522

  12. Conformal Loop quantization of gravity coupled to the standard model

    NASA Astrophysics Data System (ADS)

    Pullin, Jorge; Gambini, Rodolfo

    2016-03-01

    We consider a local conformal invariant coupling of the standard model to gravity free of any dimensional parameter. The theory is formulated in order to have a quantized version that admits a spin network description at the kinematical level like that of loop quantum gravity. The Gauss constraint, the diffeomorphism constraint and the conformal constraint are automatically satisfied and the standard inner product of the spin-network basis still holds. The resulting theory has resemblances with the Bars-Steinhardt-Turok local conformal theory, except it admits a canonical quantization in terms of loops. By considering a gauge fixed version of the theory we show that the Standard model coupled to gravity is recovered and the Higgs boson acquires mass. This in turn induces via the standard mechanism masses for massive bosons, baryons and leptons.

  13. Bose-Hubbard model with occupation-parity couplings

    NASA Astrophysics Data System (ADS)

    Sun, Kuei; Bolech, C. J.

    2014-02-01

    We study a Bose-Hubbard model having on-site repulsion, nearest-neighbor tunneling, and ferromagneticlike coupling between occupation parities of nearest-neighbor sites. For a uniform system in any dimension at zero tunneling, we obtain an exact phase diagram characterized by Mott-insulator (MI) and pair liquid phases and regions of phase separation of two MIs. For a general trapped system in one and two dimensions with finite tunneling, we perform quantum Monte Carlo and Gutzwiller mean-field calculations, both of which show the evolution of the system, as the parity coupling increases, from a superfluid to wedding-cake-structure MIs with their occupations jumping by 2. We also identify an exotic pair superfluid at relatively large tunneling strength. Our model ought to effectively describe recent findings in imbalanced Fermi gases in two-dimensional optical lattices and also potentially apply to an anisotropic version of bilinear-biquadratic spin systems.

  14. Eikonal solutions to optical model coupled-channel equations

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Khandelwal, Govind S.; Maung, Khin M.; Townsend, Lawrence W.; Wilson, John W.

    1988-01-01

    Methods of solution are presented for the Eikonal form of the nucleus-nucleus coupled-channel scattering amplitudes. Analytic solutions are obtained for the second-order optical potential for elastic scattering. A numerical comparison is made between the first and second order optical model solutions for elastic and inelastic scattering of H-1 and He-4 on C-12. The effects of bound-state excitations on total and reaction cross sections are also estimated.

  15. WWW.com: A Brief Intervention to Bolster a 5th Grader's Regrouping Skills in Math

    ERIC Educational Resources Information Center

    Waugh, Matthew; Harrison, Gina L.

    2014-01-01

    This study examined the efficacy of a brief math intervention using cognitive behaviour instruction (CBI) supplemented by a mnemonic cue system for a 5th grade student with math computation and fluency difficulties. Regrouping operations in addition and subtraction were the targeted skills. Curriculum-based measurements were conducted at the end…

  16. Proceedings of the International Conference on Educational Data Mining (EDM) (5th, Chania, Greece, June 19-21, 2012)

    ERIC Educational Resources Information Center

    International Educational Data Mining Society, 2012

    2012-01-01

    The 5th International Conference on Educational Data Mining (EDM 2012) is held in picturesque Chania on the beautiful Crete island in Greece, under the auspices of the International Educational Data Mining Society (IEDMS). The EDM 2012 conference is a leading international forum for high quality research that mines large data sets of educational…

  17. Comparing Science Learning among 4th-, 5th-, and 6th-Grade Students: STS versus Textbook-Based Instruction

    ERIC Educational Resources Information Center

    Yager, Robert E.; Choi, AeRan; Yager, Stuart O.; Akcay, Hakan

    2009-01-01

    Fifteen 4th-, 5th-, and 6th-grade teachers from five school districts each taught two sections of science--one with a Science-Technology-Society (STS) approach and the other with a more traditional textbook approach in which basic science concepts were the major organizers. Local, current, and personally relevant issues provided the context and…

  18. Process Evaluation of "Learn Young, Learn Fair": A Stress Management Programme for 5th and 6th Graders

    ERIC Educational Resources Information Center

    Kraag, Gerda; Van Breukelen, Gerard; Lamberts, Petra; Vugts, Odette; Kok, Gerjo; Fekkes, Minne; Abu-Saad, Huda Huijer

    2007-01-01

    This article describes the process evaluation of a stress management program called "Learn Young, Learn Fair" for 5th and 6th graders. Studies, reviews and meta-analyses of prevention programs report that a common limitation in studies is the restricted documentation of process factors that contribute to the success of interventions. Program…

  19. Communicating Science to Impact Learning? A Phenomenological Inquiry into 4th and 5th Graders' Perceptions of Science Information Sources

    ERIC Educational Resources Information Center

    Gelmez Burakgazi, Sevinc; Yildirim, Ali; Weeth Feinstein, Noah

    2016-01-01

    Rooted in science education and science communication studies, this study examines 4th and 5th grade students' perceptions of science information sources (SIS) and their use in communicating science to students. It combines situated learning theory with uses and gratifications theory in a qualitative phenomenological analysis. Data were gathered…

  20. From Cooks to Carpenters: Measuring - A Saleable Work Skill. Occupation Simulation Packet. Grades 5th-6th.

    ERIC Educational Resources Information Center

    Kennedy, Helena

    This teacher's guide contains simulated work experiences for 5th and 6th grade students using the isolated skill concept - measuring. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Three pre-skill activities are suggested, such as…

  1. Brief Report: Data on the Stanford-Binet Intelligence Scales (5th Ed.) in Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Coolican, Jamesie; Bryson, Susan E.; Zwaigenbaum, Lonnie

    2008-01-01

    The Fifth Edition of the Stanford-Binet Intelligence Scales (SB5; Roid, G. H. (2003). "Stanford Binet intelligence scales" (5th ed.). Itasca, IL: Riverside Publishing) is relatively new, with minimal published research on general populations and none with special populations. The present study provides information on the cognitive profiles of…

  2. Strongly Coupled Models with a Higgs-like Boson

    NASA Astrophysics Data System (ADS)

    Pich, Antonio; Rosell, Ignasi; José Sanz-Cillero, Juan

    2013-11-01

    Considering the one-loop calculation of the oblique S and T parameters, we have presented a study of the viability of strongly-coupled scenarios of electroweak symmetry breaking with a light Higgs-like boson. The calculation has been done by using an effective Lagrangian, being short-distance constraints and dispersive relations the main ingredients of the estimation. Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models with massive resonances are not in conflict with experimentalconstraints on these parameters and the recently observed Higgs-like resonance. So there is room for these models, but they are stringently constrained. The vector and axial-vector states should be heavy enough (with masses above the TeV scale), the mass splitting between them is highly preferred to be small and the Higgs-like scalar should have a WW coupling close to the Standard Model one. It is important to stress that these conclusions do not depend critically on the inclusion of the second Weinberg sum rule. We wish to thank the organizers of LHCP 2013 for the pleasant conference. This work has been supported in part by the Spanish Government and the European Commission [FPA2010-17747, FPA2011- 23778, AIC-D-2011-0818, SEV-2012-0249 (Severo Ochoa Program), CSD2007-00042 (Consolider Project CPAN)], the Generalitat Valenciana [PrometeoII/2013/007] and the Comunidad de Madrid [HEPHACOS S2009/ESP-1473].

  3. ESTIMATING GASEOUS EXCHANGES BETWEEN THE ATMOSPHERE AND PLANTS USING A COUPLED BIOCHEMICAL DRY DEPOSITION MODEL

    EPA Science Inventory

    To study gaseous exchanges between the soil, biosphere and atmosphere, a biochemical model was coupled with the latest version of Meyers Multi-Layer Deposition Model. The biochemical model describes photosynthesis and respiration and their coupling with stomatal resistance for...

  4. Health in the 5th 5-years Development Plan of Iran: Main Challenges, General Policies and Strategies.

    PubMed

    Vosoogh Moghaddam, A; Damari, B; Alikhani, S; Salarianzedeh, Mh; Rostamigooran, N; Delavari, A; Larijani, B

    2013-01-01

    Access to the right to the highest attainable level of health is a constitutional right that obliges governments and other players to take step to increase all individuals' chances of obtaining good health. At the least, health and education are two crucial requirements for this as well. Iran's vision 2025 is going to lead the country to a developed state with the highest rank of economic, scientific and technological status in the region. Enjoying health, welfare, food security, social security, equal opportunities, etc, are also considered as part of characteristics of Iranian society in 2025. Although health system of Iran has many achievements in providing health services specially for the poor following the Islamic Revolution of 1979, but the evidences gathered to develop the 5(th) 5-years economical, social and cultural plan (5(th)5YDP:2011-2015), listed a variety of main challenges in stewardship, financing, resources generation and service provision functions of the existing health system. Thus, to overcome the main challenges, about 11% of general policies of 5(th)5YDP are directly address health related issues with emphasizing on healthy human and comprehensive health approach with considering: Integration of policy making, planning, evaluation, supervision and public financing; Developing both quantity and quality of health insurance system and reducing out-of-pocket expenditures for health services to 30% by the end of the 5th plan. The strategies of 5(th)5YDP adopted by the parliament as an Act will change the health system fundamentally through tuning the main drivers; so, its implementation needs brave leaders, capable managers, motivated technical staff and social mobilization. PMID:23865015

  5. PREFACE: 5th International EEIGM/AMASE/FORGEMAT Conference on Advanced Materials Research

    NASA Astrophysics Data System (ADS)

    Ayadi, Zoubir; Czerwiec, Thierry; Horwat, David; Jamart, Brigitte

    2009-07-01

    This issue of IOP Conference Series: Materials Science and Engineering, contains manuscripts of talks that will be presented at the 5th International EEIGM/AMASE/FORGEMAT Conference on Advanced Materials Research that will be held at the Ecole Européenne d'Ingénieurs en Génie des Matériaux - European School of Materials Science and Engineering (EEIGM) in Nancy on November 4-5 2009. The conference will be organized by the EEIGM. The aim of the conference is to bring together scientists from the six European universities involved in the EEIGM and in the ''Erasmus Mundus'' AMASE Master (Advanced Materials Science and Engineering) programmes and in the Tempus FORGEMAT European project: Nancy-Université - EEIGM/INPL (Nancy, France), Universität des Saarlandes (Saarbrücken, Germany), Universitat Politècnica de Catalunya - ETSEIB (Barcelona, Spain), Luleå Tekniska Universitet (Luleå, Sweden), Universidad Politecnica de Valencia - ETSII (Valencia, Spain) and AGH University of Science and Technology, (Kralow, Poland). This conference is also open to other universities who have strong links with the EEIGM and it will provide a forum for exchange of ideas, cooperation and future directions by means of regular presentations, posters and a round-table discussion. After careful refereeing of all manuscripts, equally shared between the four editors, 26 papers have been selected for publication in this issue. The papers are grouped together into different subject categories: polymers, metallurgy, ceramics, composites and nanocomposites, simulation and characterization. The editors would like to take this opportunity to thank all the participants who submitted their manuscripts during the conference and responded in time to the editors' request at every stage from reviewing to final acceptance. The editors are indebted to all the reviewers for painstakingly reviewing the papers at very short notice. Special thanks are called for the sponsors of the conference including

  6. News from the "5th International Meeting on Inflammatory Bowel Diseases" CAPRI 2010.

    PubMed

    Latella, Giovanni; Fiocchi, Claudio; Caprili, Renzo

    2010-12-01

    At the "5th International Meeting on Inflammatory Bowel Diseases selected topics of inflammatory bowel disease (IBD), including the environment, genetics, the gut flora, the cell response and immunomodulation were discussed in order to better understand specific clinical and therapeutic aspects. The incidence of IBD continues to rise, both in low and in high-incidence areas. It is believed that factors associated with 'Westernization' may be conditioning the expression of these disorders. The increased incidence of IBD among migrants from low-incidence to high-incidence areas within the same generation suggests a strong environmental influence. The development of genome-wide association scanning (GWAS) technologies has lead to the discovery of more than 100 IBD loci. Some, as the Th 17 pathway genes, are shared between Crohn's disease (CD) and ulcerative colitis (UC), while other are IBD subtype-specific (autophagy genes, epithelial barrier genes). Disease-specific therapies targeting these pathways should be developed. Epigenetic regulation of the inflammatory response also appears to play an important role in the pathogenesis of IBD. The importance of gut flora in intestinal homeostasis and inflammation was reinforced, the concepts of eubiosis and dysbiosis were introduced, and some strategies for reverting dysbiosis to a homeostatic state of eubiosis were proposed. The current status of studies on the human gut microbiota metagenome, metaprotome, and metabolome was also presented. The cell response in inflammation, including endoplasmic reticulum (ER) stress responses, autophagy and inflammasome-dependent events were related to IBD pathogenesis. It was suggested that inflammation-associated ER stress responses may be a common trait in the pathogenesis of various chronic immune and metabolic diseases. How innate and adaptive immunity signaling events can perpetuate chronic inflammation was discussed extensively. Signal transduction pathways provide intracellular

  7. Storm Peak Laboratory 5th-6th Grade Climate and Weather Program

    NASA Astrophysics Data System (ADS)

    McCubbin, I. B.; Hallar, A. G.

    2008-12-01

    science. At the end of the day each student has a data sheet with measurements recorded from 5 locations of different elevations to take back to the classroom. Following the field trip, SPL scientists and educators visit the school for a follow-up to help children grasp concepts, represent their data set collected in graphical formats, answer questions, and evaluate students" learning. Currently, approximately 250 students annually participate in the SPL 5th and 6th grade climate education program.

  8. A Fully Coupled Computational Model of the Silylation Process

    SciTech Connect

    G. H. Evans; R. S. Larson; V. C. Prantil; W. S. Winters

    1999-02-01

    This report documents the development of a new finite element model of the positive tone silylation process. Model development makes use of pre-existing Sandia technology used to describe coupled thermal-mechanical behavior in deforming metals. Material properties and constitutive models were obtained from the literature. The model is two-dimensional and transient and focuses on the part of the lithography process in which crosslinked and uncrosslinked resist is exposed to a gaseous silylation agent. The model accounts for the combined effects of mass transport (diffusion of silylation agent and reaction product), chemical reaction resulting in the uptake of silicon and material swelling, the generation of stresses, and the resulting material motion. The influence of stress on diffusion and reaction rates is also included.

  9. Modelling of a refrigerating system coupled with a refrigerated room

    NASA Astrophysics Data System (ADS)

    Wang, Hongwei

    1991-08-01

    The development of a set of comprehensive computer models to simulate and analyze both steady state and non steady state behavior of a refrigerating system coupled with a refrigerated room is described. The refrigerating system is a single stage vapor compression system consisting of four basic elements: a reciprocating piston compressor, a dry expansion evaporator (or cooler), a shell and tube watercooled condensor and a thermostatic expansion valve. To validate the computer models, a test plant on which steady state and dynamic measurements were carried out, was set up. Experiments to determine several empirical constants encountered in the models were done, and the simulation results were compared with a series of measurements within a wide range of operation conditions. The validated models were applied to the prediction of the air distributions in a cold store and the study of a system with different capacity control systems, proving the capability and reliability of the models.

  10. Gauge coupling unification in a classically scale invariant model

    NASA Astrophysics Data System (ADS)

    Haba, Naoyuki; Ishida, Hiroyuki; Takahashi, Ryo; Yamaguchi, Yuya

    2016-02-01

    There are a lot of works within a class of classically scale invariant model, which is motivated by solving the gauge hierarchy problem. In this context, the Higgs mass vanishes at the UV scale due to the classically scale invariance, and is generated via the Coleman-Weinberg mechanism. Since the mass generation should occur not so far from the electroweak scale, we extend the standard model only around the TeV scale. We construct a model which can achieve the gauge coupling unification at the UV scale. In the same way, the model can realize the vacuum stability, smallness of active neutrino masses, baryon asymmetry of the universe, and dark matter relic abundance. The model predicts the existence vector-like fermions charged under SU(3) C with masses lower than 1 TeV, and the SM singlet Majorana dark matter with mass lower than 2.6 TeV.

  11. Influence of Physics Parameterizations and Ocean Coupling on Simulations of Tropical Cyclones using a Regional Climate Model (WRF) and a Coupled Modeling System (COAWST)

    NASA Astrophysics Data System (ADS)

    Mooney, P.; Mulligan, F. J.; Bruyere, C. L.; Bonnlander, B.

    2014-12-01

    We examine the influence of physics parameterizations and ocean coupling on the ability of the Weather Research and Forecasting (WRF) model to simulate the storm track and intensity of 2011 storms Irene and Ophelia. Of the physics parameterizations investigated - cumulus parameterizations, planetary boundary layer, microphysics, radiation, and land surface models - cumulus parameterizations have the greatest impact on WRF's ability to reproduce the two storms, particularly storm intensity. We also investigated the influence of coupling the Regional Ocean Modelling System (ROMS) to the WRF model. This was achieved using the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) modeling system which couples ROMS to WRF using the Model Coupling Toolkit (MCT). Simulated storm intensity and track are modified as a result of coupling ROMS to WRF, but coupling will not compensate for a poor initial parameterization selection.

  12. Standard model-like D-brane models and gauge couplings

    NASA Astrophysics Data System (ADS)

    Hamada, Yuta; Kobayashi, Tatsuo; Uemura, Shohei

    2015-08-01

    We systematically search intersecting D-brane models, which just realize the Standard Model chiral matter contents and gauge symmetry. We construct new classes of non-supersymmetric Standard Model-like models. We also study the gauge coupling constants of these models. The tree level gauge coupling is a function of the compactification moduli, the string scale, the string coupling and the winding numbers of D-branes. By tuning them, we examine whether the models can explain the experimental values of gauge couplings. As a result, we find that the string scale should be greater than 1014-15 GeV if the compactification scale and the string scale are of the same order.

  13. Warm stellar matter within the quark-meson-coupling model

    NASA Astrophysics Data System (ADS)

    Panda, P. K.; Providência, C.; Menezes, D. P.

    2010-10-01

    In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.

  14. Warm stellar matter within the quark-meson-coupling model

    SciTech Connect

    Panda, P. K.; Providencia, C.; Menezes, D. P.

    2010-10-15

    In the present article, we investigate stellar matter obtained within the quark-meson-coupling (QMC) model for fixed temperature and with the entropy of the order of 1 or 2 Boltzmann units per baryon for neutrino-free matter and matter with trapped neutrinos. A new prescription for the calculation of the baryon effective masses in terms of the free energy is used. Comparing the results of the present work with those obtained from the nonlinear Walecka model, smaller strangeness and neutrino fractions are predicted within QMC. As a consequence, QMC has a smaller window of metastability for conversion into a low-mass blackhole during cooling.

  15. A coupled model of fluid flow in jointed rock

    SciTech Connect

    Swenson, Daniel; Martineau, Rick; James, Mark; Brown, Don

    1991-01-01

    We present a fully coupled model of fluid flow in jointed rock, where the fluid flow depends on the joint openings and the joint openings depend on the fluid pressure. The joints and rock blocks are modeled discretely using the finite element method. Solutions for the fluid and rock are obtained and iteration is performed until both solutions converge. Example applications include an examination of the effects of back-pressure on flow in a geothermal reservoir and transient fluid injection into a reservoir.

  16. Community Surface Dynamics Modeling System and its CSDMS Modeling Tool to couple models and data (Invited)

    NASA Astrophysics Data System (ADS)

    Syvitski, J. P.; Csdms Scientific; Software Team

    2010-12-01

    CSDMS is the virtual home for a diverse community who foster and promote the modeling of earth surface processes, with emphasis on the movement of fluids, sediment and solutes through landscapes, seascapes and through their sedimentary basins. CSDMS develops, integrates, disseminates & archives software (> 150 models and 3million+ lines of code) that reflects and predicts earth surface processes over a broad range of time and space scales. CSDMS deals with the Earth's surface—the ever-changing, dynamic interface between lithosphere, hydrosphere, cryosphere, and atmosphere. CSDMS employs state-of-the-art architectures, interface standards and frameworks that make it possible to convert stand-alone models into flexible, "plug-and-play" components that can be assembled into larger applications. The CSDMS model-coupling environment offers language interoperability, structured and unstructured grids, and serves as a migration pathway for surface dynamics modelers towards High-Performance Computing (HPC). The CSDMS Modeling Tool is a key product of the overall project, as it allows earth scientists with relatively modest computer coding experience to use the CSDMS modules for earth surface dynamics research and education. The CMT Tool is platform independent. CMT can easily couple models that have followed the CSDMS protocols for model contribution: 1) Open-source license; 2) Available; 3) Vetted; 4) Open-source language; 5) Refactored for componentization; 6) Metadata & test files; 7) Clean and documented using keywords.

  17. Safer Batteries through Coupled Multiscale Modeling (ICCS 2015)

    SciTech Connect

    Turner, John A; Allu, Srikanth; Berrill, Mark A; Elwasif, Wael R; Kalnaus, Sergiy; Kumar, Abhishek; Lebrun-Grandie, Damien T; Pannala, Dr. Sreekanth; Simunovic, Srdjan

    2015-01-01

    Batteries are highly complex electrochemical systems, with performance and safety governed by coupled nonlinear electrochemical-electrical-thermal-mechanical processes over a range of spatiotemporal scales. We describe a new, open source computational environment for battery simulation known as VIBE - the Virtual Integrated Battery Environment. VIBE includes homogenized and pseudo-2D electrochemistry models such as those by Newman-Tiedemann-Gu (NTG) and Doyle- Fuller-Newman (DFN, a.k.a. DualFoil) as well as a new advanced capability known as AMPERES (Advanced MultiPhysics for Electrochemical and Renewable Energy Storage). AMPERES provides a 3D model for electrochemistry and full coupling with 3D electrical and thermal models on the same grid. VIBE/AMPERES has been used to create three-dimensional battery cell and pack models that explicitly simulate all the battery components (current collectors, electrodes, and separator). The models are used to predict battery performance under normal operations and to study thermal and mechanical response under adverse conditions.

  18. Evolution of a Coupled Marine Ice Sheet - Sea Level Model

    NASA Astrophysics Data System (ADS)

    Gomez, N.; Pollard, D.; Mitrovica, J. X.; Huybers, P.; Clark, P. U.

    2012-04-01

    An instability mechanism is widely predicted for marine ice sheets resting upon reversed bed slopes whereby ice-sheet thinning or rising sea level is thought to lead to irreversible retreat of the grounding line. Previous analyses of marine ice-sheet stability have considered the influence of a sea-level perturbation on ice-sheet stability by assuming a geographically uniform, or eustatic, change in sea level. However, gravitational, deformational and rotational effects associated with changes in the volume of grounded ice lead to markedly non-uniform spatial patterns of sea-level change. In particular, a gravitationally self-consistent sea-level theory predicts a sea-level fall in the vicinity of a shrinking ice sheet that is an order of magnitude greater amplitude than the sea-level rise that would be predicted assuming eustasy. We highlight the stabilizing influence of local sea-level changes on marine ice sheets by incorporating gravitationally self-consistent sea-level changes into a steady state model of ice sheet stability (Gomez et. al., Nature Geoscience, 2010). In addition, we develop a dynamic coupled ice sheet - sea level model to consider the impact of this stabilizing mechanism on the timescale of ice sheet retreat. The coupled system combines a sea-level model valid for a self-gravitating, viscoelastically deforming Earth to a 1D, dynamic marine ice sheet-shelf model. The evolution of the coupled model is explored for a suite of simulations in which we vary the bed slope and the forcing that initiates retreat. We find that the sea-level fall at the grounding line associated with a retreating ice sheet acts to slow the retreat; in simulations with shallow reversed bed slopes and/or small initial forcing, the drop in sea level can be sufficient to halt the retreat. The rate of sea-level change at the grounding line has an elastic component due to ongoing changes in ice-sheet geometry, and a viscous component due to past ice and ocean load changes. When

  19. The dynamics of a coupled soilscape-landscape evolution model

    NASA Astrophysics Data System (ADS)

    Welivitiya, Dimuth; Willgoose, Garry; Hancock, Greg

    2016-04-01

    In this study we present results obtained from a landform evolution model coupled with SSSPAM5D soilscape evolution model. This presentation will show a number of computer animations with this coupled model using a range of widely accepted soil profile weathering models, and erosion/armouring models. The animations clearly show that subtle changes in process can result in dramatic changes in long-term equilibrium hillslope and soilscape form. We will discuss the reasons for these differences, arguing from the various mathematical and physical assumptions modelled, and infer how observed hillslope form may provide identifiable (and perhaps quantifiable) landform and soilscape signatures of landscape and soilscape process, and in particular the coupling between the landscape and the soilscape. Specifically we have simulated soilscapes using 3 depth dependent weathering functions: 1) Exponential, 2) Humped and 3) Reversed exponential. The Exponential weathering function simulates physical weathering due to thermal effects, and the weathering rate exponentially decreases with depth. The Humped function simulates chemical and/or physical weathering with moisture feedbacks, where the highest weathering rate is at a finite depth below the surface and exponentially declines with depth. The Reversed exponential function simulates chemical weathering, and the highest weathering rate is at the soil-saprolite interface and exponentially decreases both above and below the interface. Both the Humped and Reversed exponential functions can be used as approximations to chemical weathering as they can be derived analytically by solving widely accepted geochemical weathering equations. The Humped function can arise where the weathering fluid is introduced at the top of the soil profile (e.g. rainfall equilibrated with carbon dioxide in the atmosphere), while the Reversed exponential can be derived when carbon dioxide is generated within the profile (e.g. by biodegradation of soil

  20. Upscalling processes in an ocean-atmosphere multiscale coupled model

    NASA Astrophysics Data System (ADS)

    Masson, S. G.; Berthet, S.; Samson, G.; Crétat, J.; Colas, F.; Echevin, V.; Jullien, S.; Hourdin, C.

    2015-12-01

    This work explores new pathways toward a better representation of the multi-scale physics that drive climate variability. We are analysing the key upscaling processes by which small-scale localized errors have a knock-on effect onto global climate. We focus on the Peru-Chilli coastal upwelling, an area known to hold among the strongest models biases in the Tropics. Our approach is based on the development of a multiscale coupling interface allowing us to couple WRF with the NEMO oceanic model in a configuration including 2-way nested zooms in the oceanic and/or the atmospheric component of the coupled model. Upscalling processes are evidenced and quantified by comparing three 20-year long simulations of a tropical channel (45°S-45°N), which differ by their horizontal resolution: 0.75° everywhere, 0.75°+0.25° zoom in the southeastern Pacific or 0.25° everywhere. This set of three 20-year long simulations was repeated with 3 different sets of parameterizations to assess the robustness of our results. Our results show that adding an embedded zoom over the southeastern Pacific only in the atmosphere cools down the SST along the Peru-Chili coast, which is a clear improvement. This change is associated with a displacement of the low-level cloud cover, which moves closer to the coast cooling further the coastal area SST. Offshore, we observe the opposite effect with a reduction of the cloud cover with higher resolution, which increases solar radiation and warms the SST. Increasing the resolution in the oceanic component show contrasting results according to the different set parameterization used in the experiments. Some experiment shows a coastal cooling as expected, whereas, in other cases, we observe a counterintuitive response with a warming of the coastal SST. Using at the same time an oceanic and an atmospheric zoom mostly combines the results obtained when using the 2-way nesting in only one component of the coupled model. In the best case, we archive by this

  1. Model independent predictions for rare top decays with weak coupling

    SciTech Connect

    Datta, Alakabha; Duraisamy, Murugeswaran

    2010-04-01

    Measurements at B factories have provided important constraints on new physics in several rare processes involving the B meson. New physics, if present in the b quark sector may also affect the top sector. In an effective Lagrangian approach, we write down operators, where effects in the bottom and the top sector are related. Assuming the couplings of the operators to be of the same size as the weak coupling g of the standard model and taking into account constraints on new physics from the bottom sector as well as top branching ratios, we make predictions for the rare top decays t{yields}cV, where V={gamma}, Z. We find branching fractions for these decays within possible reach of the LHC. Predictions are also made for t{yields}sW.

  2. Particle production within the quark meson coupling model

    SciTech Connect

    Panda, P. K.; Menezes, D. P.; Providencia, C.

    2009-07-15

    Quark-meson coupling (QMC) models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter. In the regime of hot hadronic matter very few calculations exist using the QMC model, in particular when applied to particle yields in heavy ion collisions. In the present work, we identify the free energy of the bag with the effective mass of the baryons and we calculate the particle production yields on a Au+Au collision at the BNL Relativistic Heavy Ion Collider (RHIC) with the QMC model and compare them with results obtained previously with other relativistic models. A smaller temperature for the fireball, T=132 MeV, is obtained because of the smaller effective baryon masses predicted by QMC. QMC was also applied to the description of particle yields at the CERN Super Proton Synchrotron (SPS) in Pb+Pb collisions.

  3. Thermodynamics of the BMN matrix model at strong coupling

    NASA Astrophysics Data System (ADS)

    Costa, Miguel S.; Greenspan, Lauren; Penedones, João; Santos, Jorge E.

    2015-03-01

    We construct the black hole geometry dual to the deconfined phase of the BMN matrix model at strong 't Hooft coupling. We approach this solution from the limit of large temperature where it is approximately that of the non-extremal D0-brane geometry with a spherical S 8 horizon. This geometry preserves the SO(9) symmetry of the matrix model trivial vacuum. As the temperature decreases the horizon becomes deformed and breaks the SO(9) to the SO(6) × SO(3) symmetry of the matrix model. When the black hole free energy crosses zero the system undergoes a phase transition to the confined phase described by a Lin-Maldacena geometry. We determine this critical temperature, whose computation is also within reach of Monte Carlo simulations of the matrix model.

  4. Coupled Hydro-Mechanical Modeling of Fluid Geological Storage

    NASA Astrophysics Data System (ADS)

    Castelletto, N.; Garipov, T.; Tchelepi, H. A.

    2013-12-01

    The accurate modeling of the complex coupled physical processes occurring during the injection and the post-injection period is a key factor for assessing the safety and the feasibility of anthropogenic carbon dioxide (CO2) sequestration in subsurface formations. In recent years, it has become widely accepted the importance of the coupling between fluid flow and geomechanical response in constraining the sustainable pressure buildup caused by fluid injection relative to the caprock sealing capacity, induced seismicity effects and ground surface stability [e.g., Rutqvist, 2012; Castelletto et al., 2013]. Here, we present a modeling approach based on a suitable combination of Finite Volumes (FVs) and Finite Elements (FEs) to solve the coupled system of partial differential equations governing the multiphase flow in a deformable porous medium. Specifically, a FV method is used for the flow problem while the FE method is adopted to address the poro-elasto-plasticity equations. The aim of the present work is to compare the performance and the robustness of unconditionally stable sequential-implicit schemes [Kim et al., 2011] and the fully-implicit method in solving the algebraic systems arising from the discretization of the governing equations, for both normally conditioned and severely ill-conditioned problems. The two approaches are tested against well-known analytical solutions and experimented with in a realistic application of CO2 injection in a synthetic aquifer. References: - Castelletto N., G. Gambolati, and P. Teatini (2013), Geological CO2 sequestration in multi-compartment reservoirs: Geomechanical challenges, J. Geophys. Res. Solid Earth, 118, 2417-2428, doi:10.1002/jgrb.50180. - Kim J., H. A. Tchelepi, and R. Juanes (2011), Stability, accuracy and efficiency of sequential methods for coupled flow and geomechanics, SPE J., 16(2), 249-262. - Rutqvist J. (2012), The geomechanics of CO2 storage in deep sedimentary formations, Geotech. Geol. Eng., 30, 525-551.

  5. A fully coupled thermal, chemical, mechanical cookoff model

    SciTech Connect

    Hobbs, M.L.; Baer, M.R.; Gross, R.J.

    1994-05-01

    Cookoff modeling of confined energetic materials involves the coupling of thermal, chemical and mechanical effects. In the past, modeling has focussed on the prediction of thermal runaway with little regard to the effects of mechanical behavior of the energetic material. To address the mechanical response of the energetic material, a constitutive submodel has been developed which can be incorporated into thermal-chemical-mechanical analysis. This work presents development of this submodel and its incorporation into a fully coupled one-dimensional, thermal-chemical-mechanical computer code to simulate thermal initiation of energetic materials. Model predictions include temperature, chemical species, stress, strain, solid/gas pressure, solid/gas density, yield function, and gas volume fraction. Sample results from a scaled aluminum tube filled with RDX exposed to a constant temperature bath at 500 K will be displayed. The micromechanical submodel is based on bubble mechanics which describes nucleation, decomposition, and elastic/plastic mechanical behavior. This constitutive material description requires input of temperatures and reacted fraction of the energetic material as provided by the reactive heat flow code, XCHEM, and the mechanical response is predicted using a quasistatic mechanics code, SANTOS. A parametric sensitivity analysis indicates that a small degree of decomposition causes significant pressurization of the energetic material, which implies that cookoff modeling must consider the strong interaction between thermal-chemistry and mechanics. This document consists of view graphs from the poster session.

  6. Interchain coupling and 3D modeling of trans-polyacetylene

    SciTech Connect

    Bronold, F.; Saxena, A.; Bishop, A.R.

    1992-01-01

    In spite of the success of the SSH model for trans-polyacetylene in interpreting many experimental results (e.g. optical and magnetic properties) there remain some aspects of the real material which are outside the scope of the simple 1D model. Especially ordering phenomena of doped and undoped trans-polyacetylene as well as transport properties (e.g. electronic and thermal conductivity) are beyond a 1D description. There are many attempts to construct a transport theory for this novel class of materials using solitons or polaxons as the basic ingredients. But so far it is not yet clear whether these typical 1D excitations still exist in crystalline transpolyacetylene. Therefore, to clarify the role which intrinsic self-localized nonlinear excitations characteristic of 1D models play in the bulk (3D) material, we study the stability of a polaronic excitation against interchain coupling. As a preliminary step we consider first two coupled t-(CH){sub x}-chains where the {pi}-electrons are allowed to hop from one chain to the other. Then we introduce a 3D generalization of the SSH model and study a polaron in a 3D crystalline environment.

  7. Interchain coupling and 3D modeling of trans-polyacetylene

    SciTech Connect

    Bronold, F.; Saxena, A.; Bishop, A.R.

    1992-09-01

    In spite of the success of the SSH model for trans-polyacetylene in interpreting many experimental results (e.g. optical and magnetic properties) there remain some aspects of the real material which are outside the scope of the simple 1D model. Especially ordering phenomena of doped and undoped trans-polyacetylene as well as transport properties (e.g. electronic and thermal conductivity) are beyond a 1D description. There are many attempts to construct a transport theory for this novel class of materials using solitons or polaxons as the basic ingredients. But so far it is not yet clear whether these typical 1D excitations still exist in crystalline transpolyacetylene. Therefore, to clarify the role which intrinsic self-localized nonlinear excitations characteristic of 1D models play in the bulk (3D) material, we study the stability of a polaronic excitation against interchain coupling. As a preliminary step we consider first two coupled t-(CH){sub x}-chains where the {pi}-electrons are allowed to hop from one chain to the other. Then we introduce a 3D generalization of the SSH model and study a polaron in a 3D crystalline environment.

  8. A coupling model for amplified spontaneous emission in laser resonators

    NASA Astrophysics Data System (ADS)

    Su, Hua; Wang, Xiaojun; Shang, Jianli; Yu, Yi; Tang, Chun

    2015-10-01

    The competition between amplified spontaneous emission (ASE) and main laser in solid-state laser resonators is investigated both theoretically and experimentally. A coupled model using the spatial volume integral instead of the Monte Carlo type raytrace technique is proposed to depict ASE in the laser resonators. This model is able to evaluate all possible reflections at both the polishing surface and the diffusive side, to calculate ASE for an inhomogeneous gain distribution, and to include the spectral correction. An experiment is carefully designed to verify the theoretical model and to investigate the distinct physical properties caused by the coupling between ASE and the laser oscillations. The experimental data exhibit an excellent agreement with the theoretical predictions. According to that model, we confirm that ASE in thin-disk lasers can be characterized approximately by the product of the threshold gain of the resonator and the diameter of the disks, as laser modes are highly overlapped with the pumping beam. Theoretical evaluation shows that the scattering characteristic of the disk side impacts on ASE significantly. Furthermore, we point out that ASE decreases output laser power by affecting threshold pumping power, while slope efficiency is not changed by ASE. This observation provides us with a simple way to estimate the decrease of the optical efficiency by ASE.

  9. High-resolution reactive transport: A coupled parallel hydrogeochemical model

    NASA Astrophysics Data System (ADS)

    Beisman, J. J.; Maxwell, R. M.; Steefel, C. I.; Sitchler, A.; Molins, S.

    2013-12-01

    Subsurface hydrogeochemical systems are an especially complex component of the terrestrial environment and play host to a multitude of interactions. Parameterizations of these interactions are perhaps the least understood component of terrestrial systems, presenting uncertainties in the predictive understanding of biogeochemical cycling and transport. Thorough knowledge of biogeochemical transport processes is critical to the quantification of carbon/nutrient fluxes in the subsurface, and to the development of effective contaminant remediation techniques. Here we present a coupled parallel hydrogeochemical model, ParCrunchFlow, as a tool to further our understanding of governing processes and interactions in natural hydrogeochemical systems. ParCrunchFlow is a coupling of the reactive transport simulator CrunchFlow with the hydrologic model ParFlow. CrunchFlow is a multicomponent reactive flow and transport code that can be used to simulate a range of important processes and environments, including reactive contaminant transport, chemical weathering, carbon sequestration, biogeochemical cycling, and water-rock interaction. ParFlow is a parallel, three-dimensional, variably-saturated, coupled surface-subsurface flow and transport code with the ability to simulate complex topography, geology, and heterogeneity. ParCrunchflow takes advantage of the efficient parallelism built into Parflow, allowing the numerical simulation of reactive transport processes in chemically and physically heterogeneous media at high spatial resolutions. This model provides an ability to further examine the interactions and feedbacks between biogeochemical systems and complex subsurface flow fields. In addition to the details of model construction, results will be presented that show floodplain nutrient cycling and the effects of heterogeneity on small-scale mixing reactions at the Department of Energy's Old Rifle Legacy site.

  10. Models of coupled salt and water transport across leaky epithelia.

    PubMed

    Weinstein, A M; Stephenson, J L

    1981-05-15

    A general formulation is presented for the verification of isotonic transport and for the assignment of a degree of osmotic coupling in any epithelial model. In particular, it is shown that the concentration of the transported fluid in the presence of exactly equal bathing media is, in general, not a sufficient calculation by which to decide the issue of isotonicity of transport. Within this framework, two epithelial models are considered: (1) A nonelectrolyte compartment model of the lateral intercellular space is presented along with its linearization about the condition of zero flux. This latter approximate model is shown to be useful in the estimation of deviation from isotonicity, intraepithelial solute polarization effects, and the capacity to transport water against a gradient. In the case of uphill water transport, some limitations of a model of fixed geometry are indicated and the advantage of modeling a compliant interspace is suggested. (2) A comprehensive model of cell and channel is described which includes the major electrolytes and the possible presence of intraepithelial gradients. The general approach to verification of isotonicity is illustrated for this numerical model. In addition, the insights about parameter dependence gained from the linear compartment model are shown to be applicable to understanding this large simulation. PMID:6264088

  11. PREFACE: 5th DAE-BRNS Workshop on Hadron Physics (Hadron 2011)

    NASA Astrophysics Data System (ADS)

    Jyoti Roy, Bidyut; Chatterjee, A.; Kailas, S.

    2012-07-01

    The 5th DAE-BRNS Workshop on Hadron Physics was held at the Bhabha Atomic Research Centre (BARC), Mumbai from 31 October to 4 November 2011. This workshop series, supported by the Board of Research in Nuclear Sciences, Department of Atomic Energy (BRNS, DAE), Govt. of India, began ten years ago with the first one being held at BARC, Mumbai in October 2002. The second one was held at Puri in 2005, organized jointly by Institute of Physics, Bhubneswar and Saha Institute of Nuclear Physics, Kolkata. The 3rd and 4th ones took place, respectively, at Shantineketan in 2006, organized by Visva Bharati University, and at Aligarh in 2008, organized by Aligarh Muslim University, Aligarh. The aim of the present workshop was to bring together the experts and young researchers in the field of hadron physics (both experiment and theory) and to have in-depth discussions on the current research activities in this field. The format of the workshop was: a series of review lectures by various experts from India and abroad, the presentation of advanced research results by researchers in the field, and a review of major experimental programs being planned and pursued in major laboratories in the field of hadron physics, with the aim of providing a platform for the young participants for interaction with their peers. The upcoming international FAIR facility at GSI is a unique future facility for studies of hadron physics in the charm sector and hyper nuclear physics. The Indian hadron physics community is involved in this mega science project and is working with the PANDA collaboration on the development of detectors, simulation and software tools for the hadron physics programme with antiprotons at FAIR. A one-day discussion session was held at this workshop to discuss India-PANDA activities, the current collaboration status and the work plan. This volume presents the workshop proceedings consisting of lectures and seminars which were delivered during the workshop. We are thankful to

  12. EDITORIAL: 5th International Symposium on Particle Image Velocimetry, PIV'03

    NASA Astrophysics Data System (ADS)

    Sung, Hyung Jin; Kim, Kyung Chun; Lee, Sang Joon

    2004-06-01

    The advent of particle image velocimetry (PIV) in the late 20th century brought about a paradigm change in the technique of flow field measurement, from point measurement to field measurement. This revolution is a result of the recent advances in computers, video cameras, optics and lasers and a deeper understanding of the theory of image processing, and such advances continue by keeping pace with leading-edge technologies such as biotechnology, nanotechnology and so forth. Recently, the PIV technique has been extended in new directions such as stereoscopic PIV, holographic PIV, dynamic PIV, micro PIV and simultaneous PLIF/PIV techniques. This special issue contains research dealing with many of the most recent developments in PIV. The papers were selected from more than 120 papers presented at the 5th International Symposium on Particle Image Velocimetry (PIV'03) held in Busan, Korea, during 22-24 September 2003. Special thanks are due to the invited speakers who have contributed their original work to this special issue, which will enhance the academic reputation of Measurement Science and Technology (MST). Fourteen papers were selected by the Scientific Committee of PIV'03. After the standard refereeing process of MST, nine papers were finally accepted for publication. The selected papers can be categorized into three groups: new PIV algorithms and evaluation methods, three-dimensional velocity field measurement techniques and micro/bio PIV applications. As a new PIV technique, Lecuona et al introduced PIV evaluation algorithms for industrial applications having high shear flow structures. Billy et al used a single-pixel-based cross-correlation method for measuring flow inside a microchannel. Foucaut et al carried out PIV optimization using spectral analysis for the study of turbulent flows. Doh et al applied a 3D PTV method to the wake behind a sphere using three CCD cameras. Hori and Sakakibara developed a high-speed scanning stereoscopic PIV system and

  13. The 5th Conference on Asian Trends in Prostate Cancer Hormone Therapy.

    PubMed

    Akaza, Hideyuki; Moore, Malcolm A; Chang, Shu-Jen; Cheng, Christopher; Choi, Han Yong; Esuvaranathan, Kesavan; Hinotsu, Shiro; Hong, Sung-Joon; Kim, Choung-Soo; Kim, Wun-Jae; Murai, Masaru; Naito, Seiji; Soebadi, Doddy; Song, Jae-Mann; Umbas, Rainy; Usami, Michiyuki; Xia, Shujie; Yang, Chi-Rei

    2007-01-01

    The Conference on Asian Trends in Prostate Cancer Hormone Therapy is an annual forum for Asian urologists now in its 5th year. The 2006 conference, held in Bali, Indonesia, was attended by 27 leading urologic oncologists from China, Indonesia, Japan, Korea, Singapore, and Taiwan and featured a packed program of presentations and discussions on a wide range of topics such as relationships among clinicians and the newly opened Asia Regional Office for Cancer Control of the International Union Against Cancer (UICC), detection rates of prostate cancer by biopsy in each of the 6 Asian countries, and favored treatment modalities for hormone-refractory prostate cancer (HRPC) in each country. The first session of the conference kicked off with a keynote lecture entitled "Activities of the UICC ARO". UICC's new office will be the nerve center for its activities in the Asia region. Along with the Asian Pacific Organization for Cancer Prevention (APOCP), UICC aims to shift the focus of attention to cancer control. As such APOCP's long-running publication the APJCP is to be re-launched as the Asian Pacific Journal of Cancer Control. Although UICC is primarily concerned with cancer, several risk factors for cancer are common also to other non-communicable diseases such as diabetes and heart disease, and an important strategy is to implement measures to control these various pathologic conditions as a whole. Apart from contributing to an Asian prostate cancer registry the UICC-ARO will provide training courses, working groups, and assistance in collecting and processing data. The keynote lecture was followed by a roundtable discussion on possible ways in which clinicians from each Asian country can work with UICC. A number of suggestions were put forth including better registration, epidemiology research, possible implementation of UICC prostate cancer guidelines, early detection and screening, and roles of diet and phytotherapy. The underlying reasons for the large but

  14. PREFACE: The 5th International Conference on Radiotherapy Gel Dosimetry (DOSGEL 2008)

    NASA Astrophysics Data System (ADS)

    Maris, Thomas G.; Pappas, Evangelos

    2009-07-01

    The International Conference on Radiotherapy Gel Dosimetry (DOSGEL) is held every two years. Its purpose is to bring together basic science and clinical researchers, medical physicists and clinicians from around the world to discuss the state-of-the-art of the gel dosimetry technique and to set the directions and trends for its future improvements. Gel dosimetry can be broadly defined as using a gel that can react to the absorption of ionizing radiation, and that can retain this information which can subsequently be retrieved by an external imaging modality. Examples of radiation-sensitive gels include, but are not limited to, polymer gel dosimeters, Fricke gel dosimeters and others. Imaging modalities that are of general use in this field are (in alphabetical order) magnetic resonance imaging (MRI), optical light computed tomography and x-ray computed tomography. This volume comprises the proceedings of the 5th International Conference on Radiotherapy Gel Dosimetry (DOSGEL 2008). The conference, organised by the University of Crete, Medical Physics Department, took place in Hersonissos, Crete, Greece from 29 September to 3 October 2008. The meeting aimed to continue the series of biannual DOSGEL conferences and focused on the promotion of gel dosimetry techniques by setting the trends for their future improvements. The main scientific session topics of DOSGEL 2008 were the following: Chemistry and fundamental properties of polymer gel dosimeters Gel dosimetry with Optical Computed Tomography Gel dosimetry with Magnetic Resonance Imaging Gel dosimetry with other than Optical CT and MR scan Techniques Other 3D dosimeters Gel dosimetry applications Local Organizing Committee Thomas G Maris (University of Crete, Greece, Chairman DOSGEL 2008) John Damilakis (University of Crete, Greece) Evangelos Pappas (University of Crete, Greece) Antonios Papadakis (University of Crete, Greece) Fotini Zacharopoulou (University of Crete, Greece) John Stratakis (University of Crete

  15. Status of the seamless coupled modelling system ICON-ART

    NASA Astrophysics Data System (ADS)

    Vogel, Bernhard; Rieger, Daniel; Schroeter, Jenniffer; Bischoff-Gauss, Inge; Deetz, Konrad; Eckstein, Johannes; Foerstner, Jochen; Gasch, Philipp; Ruhnke, Roland; Vogel, Heike; Walter, Carolin; Weimer, Michael

    2016-04-01

    The integrated modelling framework ICON-ART [1] (ICOsahedral Nonhydrostatic - Aerosols and Reactive Trace gases) extends the numerical weather prediction modelling system ICON by modules for gas phase chemistry, aerosol dynamics and related feedback processes. The nonhydrostatic global modelling system ICON [2] is a joint development of German Weather Service (DWD) and Max Planck Institute for Meteorology (MPI-M) with local grid refinement down to grid sizes of a few kilometers. It will be used for numerical weather prediction, climate projections and for research purposes. Since January 2016 ICON runs operationally at DWD for weather forecast on the global scale with a grid size of 13 km. Analogous to its predecessor COSMO-ART [3], ICON-ART is designed to account for feedback processes between meteorological variables and atmospheric trace substances. Up to now, ICON-ART contains the dispersion of volcanic ash, radioactive tracers, sea salt aerosol, as well as ozone-depleting stratospheric trace substances [1]. Recently, we have extended ICON-ART by a mineral dust emission scheme with global applicability and nucleation parameterizations which allow the cloud microphysics to explicitly account for prognostic aerosol distributions. Also very recently an emission scheme for volatile organic compounds was included. We present first results of the impact of natural aerosol (i.e. sea salt aerosol and mineral dust) on cloud properties and precipitation as well as the interaction of primary emitted particles with radiation. Ongoing developments are the coupling with a radiation scheme to calculate the photolysis frequencies, a coupling with the RADMKA (1) chemistry and first steps to include isotopologues of water. Examples showing the capabilities of the model system will be presented. This includes a simulation of the transport of ozone depleting short-lived trace gases from the surface into the stratosphere as well as of long-lived tracers. [1] Rieger, D., et al

  16. The kinesin walk: a dynamic model with elastically coupled heads.

    PubMed Central

    Derényi, I; Vicsek, T

    1996-01-01

    Recently individual two-headed kinesin molecules have been studied in in vitro motility assays revealing a number of their peculiar transport properties. In this paper we propose a simple and robust model for the kinesin stepping process with elastically coupled Brownian heads that show all of these properties. The analytic and numerical treatment of our model results in a very good fit to the experimental data and practically has no free parameters. Changing the values of the parameters in the restricted range allowed by the related experimental estimates has almost no effect on the shape of the curves and results mainly in a variation of the zero load velocity that can be directly fitted to the measured data. In addition, the model is consistent with the measured pathway of the kinesin ATPase. PMID:8692894

  17. Model Organisms in G Protein-Coupled Receptor Research.

    PubMed

    Langenhan, Tobias; Barr, Maureen M; Bruchas, Michael R; Ewer, John; Griffith, Leslie C; Maiellaro, Isabella; Taghert, Paul H; White, Benjamin H; Monk, Kelly R

    2015-09-01

    The study of G protein-coupled receptors (GPCRs) has benefited greatly from experimental approaches that interrogate their functions in controlled, artificial environments. Working in vitro, GPCR receptorologists discovered the basic biologic mechanisms by which GPCRs operate, including their eponymous capacity to couple to G proteins; their molecular makeup, including the famed serpentine transmembrane unit; and ultimately, their three-dimensional structure. Although the insights gained from working outside the native environments of GPCRs have allowed for the collection of low-noise data, such approaches cannot directly address a receptor's native (in vivo) functions. An in vivo approach can complement the rigor of in vitro approaches: as studied in model organisms, it imposes physiologic constraints on receptor action and thus allows investigators to deduce the most salient features of receptor function. Here, we briefly discuss specific examples in which model organisms have successfully contributed to the elucidation of signals controlled through GPCRs and other surface receptor systems. We list recent examples that have served either in the initial discovery of GPCR signaling concepts or in their fuller definition. Furthermore, we selectively highlight experimental advantages, shortcomings, and tools of each model organism. PMID:25979002

  18. Model for a transformer-coupled toroidal plasma source

    SciTech Connect

    Rauf, Shahid; Balakrishna, Ajit; Chen Zhigang; Collins, Ken

    2012-01-15

    A two-dimensional fluid plasma model for a transformer-coupled toroidal plasma source is described. Ferrites are used in this device to improve the electromagnetic coupling between the primary coils carrying radio frequency (rf) current and a secondary plasma loop. Appropriate components of the Maxwell equations are solved to determine the electromagnetic fields and electron power deposition in the model. The effect of gas flow on species transport is also considered. The model is applied to 1 Torr Ar/NH{sub 3} plasma in this article. Rf electric field lines form a loop in the vacuum chamber and generate a plasma ring. Due to rapid dissociation of NH{sub 3}, NH{sub x}{sup +} ions are more prevalent near the gas inlet and Ar{sup +} ions are the dominant ions farther downstream. NH{sub 3} and its by-products rapidly dissociate into small fragments as the gas flows through the plasma. With increasing source power, NH{sub 3} dissociates more readily and NH{sub x}{sup +} ions are more tightly confined near the gas inlet. Gas flow rate significantly influences the plasma characteristics. With increasing gas flow rate, NH{sub 3} dissociation occurs farther from the gas inlet in regions with higher electron density. Consequently, more NH{sub 4}{sup +} ions are produced and dissociation by-products have higher concentrations near the outlet.

  19. Global Magnetospheric Simulations: coupling with ionospheric and solar wind models

    NASA Astrophysics Data System (ADS)

    Lapenta, Giovanni; Olshevskyi, Vyacheslav; Amaya, Jorge; Deca, Jan; Markidis, Stefano; Vapirev, Alexander

    2013-04-01

    We present results on the global fully kinetic model of the magnetosphere of the Earth. The simulations are based on the iPic3D code [1] that treats kinetically all plasma species solving implicitly the equations of motion for electrons and ions, coupled with the Maxwell equations. We present results of our simulations and discuss the coupling at the inner boundary near the Earth with models of the ionosphere and at the outer boundary with models of the arriving solar wind. The results are part of the activities of the Swiff FP7 project: www.swiff.eu [1] Stefano Markidis, Giovanni Lapenta, Rizwan-uddin, Multi-scale simulations of plasma with iPIC3D, Mathematics and Computers in Simulation, Volume 80, Issue 7, March 2010, Pages 1509-1519, ISSN 0378-4754, 10.1016/j.matcom.2009.08.038 [2] Giovanni Lapenta, Particle simulations of space weather, Journal of Computational Physics, Volume 231, Issue 3, 1 February 2012, Pages 795-821, ISSN 0021-9991, 10.1016/j.jcp.2011.03.035.

  20. Modelling of strongly coupled particle growth and aggregation

    NASA Astrophysics Data System (ADS)

    Gruy, F.; Touboul, E.

    2013-02-01

    The mathematical modelling of the dynamics of particle suspension is based on the population balance equation (PBE). PBE is an integro-differential equation for the population density that is a function of time t, space coordinates and internal parameters. Usually, the particle is characterized by a unique parameter, e.g. the matter volume v. PBE consists of several terms: for instance, the growth rate and the aggregation rate. So, the growth rate is a function of v and t. In classical modelling, the growth and the aggregation are independently considered, i.e. they are not coupled. However, current applications occur where the growth and the aggregation are coupled, i.e. the change of the particle volume with time is depending on its initial value v0, that in turn is related to an aggregation event. As a consequence, the dynamics of the suspension does not obey the classical Von Smoluchowski equation. This paper revisits this problem by proposing a new modelling by using a bivariate PBE (with two internal variables: v and v0) and by solving the PBE by means of a numerical method and Monte Carlo simulations. This is applied to a physicochemical system with a simple growth law and a constant aggregation kernel.

  1. Model Organisms in G Protein–Coupled Receptor Research

    PubMed Central

    Barr, Maureen M.; Bruchas, Michael R.; Ewer, John; Griffith, Leslie C.; Maiellaro, Isabella; Taghert, Paul H.; White, Benjamin H.

    2015-01-01

    The study of G protein–coupled receptors (GPCRs) has benefited greatly from experimental approaches that interrogate their functions in controlled, artificial environments. Working in vitro, GPCR receptorologists discovered the basic biologic mechanisms by which GPCRs operate, including their eponymous capacity to couple to G proteins; their molecular makeup, including the famed serpentine transmembrane unit; and ultimately, their three-dimensional structure. Although the insights gained from working outside the native environments of GPCRs have allowed for the collection of low-noise data, such approaches cannot directly address a receptor’s native (in vivo) functions. An in vivo approach can complement the rigor of in vitro approaches: as studied in model organisms, it imposes physiologic constraints on receptor action and thus allows investigators to deduce the most salient features of receptor function. Here, we briefly discuss specific examples in which model organisms have successfully contributed to the elucidation of signals controlled through GPCRs and other surface receptor systems. We list recent examples that have served either in the initial discovery of GPCR signaling concepts or in their fuller definition. Furthermore, we selectively highlight experimental advantages, shortcomings, and tools of each model organism. PMID:25979002

  2. On Coupling Models Using Model-Checking: Effects of Irinotecan Injections on the Mammalian Cell Cycle

    NASA Astrophysics Data System (ADS)

    de Maria, Elisabetta; Fages, François; Soliman, Sylvain

    In systems biology, the number of models of cellular processes increases rapidly, but re-using models in different contexts or for different questions remains a challenging issue. In this paper, we show how the validation of a coupled model and the optimization of its parameters with respect to biological properties formalized in temporal logics, can be done automatically by model-checking. More specifically, we illustrate this approach with the coupling of existing models of the mammalian cell cycle, the p53-based DNA-damage repair network, and irinotecan metabolism, with respect to the biological properties of this anticancer drug.

  3. Upscaled modeling of CO2 injection with coupled thermal processes

    NASA Astrophysics Data System (ADS)

    Gasda, Sarah; Stephansen, Annette; Dahle, Helge; Aavatsmark, Ivar

    2013-04-01

    Large-scale models of CO2 storage in geological formations must capture the relevant physical, chemical and thermodynamical processes that affect the migration and ultimate fate of injected CO2. These processes should be modeled over the appropriate length and time scales. Some important mechanisms include convection-driven dissolution, caprock roughness, and local capillary effects, all of which can impact the direction and speed of the plume as well as long-term trapping efficiency. In addition, CO2 can be injected at a different temperature than reservoir conditions, leading to significant density variation within the plume over space and time. This impacts buoyancy and migration patterns, which becomes particularly important for injection sites with temperature and pressure conditions near the critical point. Therefore, coupling thermal processes with fluid flow should be considered in order to correctly capture plume migration and trapping within the reservoir. A practical modeling approach for CO2 storage over relatively large length and time scales is the vertical-equilibrium model, which solves partially integrated conservation equations for flow in two lateral dimensions. We couple heat transfer within the vertical equilibrium framework for fluid flow, focusing on the thermal processes that most impact the CO2 plume. We investigate a simplified representation of heat exchange between the plume and the reservoir that also includes transport of heat within the plume. In addition, we explore CO2 thermodynamic models for reliable prediction of density under different injection pressures, temperatures and composition. The model concept is demonstrated on simple systems and applied to a realistic storage aquifer.

  4. Coupled atmosphere-ocean models of Titan's past

    NASA Astrophysics Data System (ADS)

    McKay, C. P.; Pollack, J. B.; Lunine, J. I.; Courtin, R.

    1993-03-01

    The behavior and possible past evolution of fully coupled atmosphere and ocean model of Titan are investigated. It is found that Titan's surface temperature was about 20 K cooler at 4 Gyr ago and will be about 5 K warmer 0.5 Gyr in the future. The change in solar luminosity and the conversion of oceanic CH4 to C2H6 drive the evolution of the ocean and atmosphere over time. Titan appears to have experienced a frozen epoch about 3 Gyr ago independent of whether an ocean is present or not. This finding may have important implications for understanding the inventory of Titan's volatile compounds.

  5. Magnetosphere-thermosphere coupling - An experiment in interactive modeling

    NASA Technical Reports Server (NTRS)

    Forbes, Jeffrey M.; Harel, Moshe

    1989-01-01

    The present use of the Rice convection model to investigate the electrodynamic coupling of the thermosphere to the inner magnetosphere encompasses the effects of EUV-driven and convection-driven neutral winds under quasi-equilibrium conditions. Convection-driven winds are included self-consistently and interactively; a steady-state wind parameterization is written analytically in terms of the electrostatic potential, which is in turn included in a closed-loop calculation for the electric potential itself. The simulations conducted show that, as the neutral system approaches a quasi-equilibrium state, the neutral winds play a much more significant role.

  6. Hypernuclei in the quark-meson coupling model

    SciTech Connect

    K. Tsushima, P. A. M. Guichon

    2010-07-01

    We present results of hypernuclei calculated in the latest quark-meson coupling (QMC) model, where the effect of the mean scalar field in-medium on the one-gluon exchange hyperfine interaction, is also included self-consistently. The extra repulsion associated with this increased hyperfine interaction in-medium completely changes the predictions for {\\Sigma} hypernuclei. Whereas in the earlier version of QMC they were bound by an amount similar to {\\Lambda} hypernuclei, they are unbound in the latest version of QMC, in qualitative agreement with the experimental absence of such states.

  7. Dynamic model of neural networks with asymmetric diluted couplings

    NASA Astrophysics Data System (ADS)

    Choi, M. Y.; Choi, Meekyoung

    1990-06-01

    We study an asymmetric diluted version of the dynamic model for neural networks proposed recently, which explicitly takes into account the existence of several time scales without discretizing the time. The dynamics is neither totally synchronous nor totally asynchronous, and the couplings in the neural networks are asymmetric. These considerations may be regarded as more biologically realistic. We obtain the phase diagram as a function of the temperature ɛ-1, the capacity α, and the ratio a of the refractory period to the action potential duration.

  8. Coupled thermal-hydraulic-chemical modelling of enhanced geothermal systems

    NASA Astrophysics Data System (ADS)

    Bächler, D.; Kohl, T.

    2005-05-01

    The study investigates thermal-, hydraulic- and chemically coupled processes of enhanced geothermal systems (EGS). On the basis of the two existing numerical codes, the finite element program FRACTURE and the geochemical module of CHEMTOUGH, FRACHEM was developed, to simulate coupled thermal-hydraulic-chemical (THC) processes, accounting for the Soultz specific conditions such as the high salinity of the reservoir fluid and the high temperatures. The finite element part calculates the thermal and hydraulic field and the geochemical module the chemical processes. According to the characteristics of the Soultz EGS reservoir, the geochemical module was modified. (i) The Debye-Huckel approach was replaced by the Pitzer formalism. (ii) New kinetic laws for calcite, dolomite, quartz and pyrite were implemented. (iii) The porosity-permeability relation was replaced by a new relation for fractured rock. (iv) The possibility of re-injecting the produced fluid was implemented. The sequential non-iterative approach (SNIA) was used to couple transport and reactions. Sensitivity analyses proved the proper functionality of FRACHEM, but highlighted the sensitivity of the SNIA approach to time steps. To quantify the FRACHEM results, a comparative simulation with the code SHEMAT was conducted, which validated FRACHEM. Coupled THC processes in a fractured zone in the Soultz reservoir at 3500 m (T0= 165 °C), which occur as a result of the injection of fluid (Tinj= 65 °C) at one end of the zone and the production at the other end, were modelled for 2 yr. Calcite is the most reactive mineral and therefore the porosity and permeability evolution results from the calcite reactions: near the injection point, porosity and permeability increase and near the production well they decrease. After 2 yr, the system seems to be very close to steady-state. Therefore, mineral dissolution and precipitation during the circulation of the fluid in the reservoir do not represent a limiting factor on

  9. Drift dynamics in a coupled model initialized for decadal forecasts

    NASA Astrophysics Data System (ADS)

    Sanchez-Gomez, Emilia; Cassou, Christophe; Ruprich-Robert, Yohan; Fernandez, Elodie; Terray, Laurent

    2016-03-01

    Drifts are always present in models when initialized from observed conditions because of intrinsic model errors; those potentially affect any type of climate predictions based on numerical experiments. Model drifts are usually removed through more or less sophisticated techniques for skill assessment, but they are rarely analysed. In this study, we provide a detailed physical and dynamical description of the drifts in the CNRM-CM5 coupled model using a set of decadal retrospective forecasts produced within CMIP5. The scope of the paper is to give some physical insights and lines of approach to, on one hand, implement more appropriate techniques of initialisation that minimize the drift in forecast mode, and on the other hand, eventually reduce the systematic biases of the models. We first document a novel protocol for ocean initialization adopted by the CNRM-CERFACS group for forecasting purpose in CMIP5. Initial states for starting dates of the predictions are obtained from a preliminary integration of the coupled model where full-field ocean surface temperature and salinity are restored everywhere to observations through flux derivative terms and full-field subsurface fields (below the prognostic ocean mixed layer) are nudged towards NEMOVAR reanalyses. Nudging is applied only outside the 15°S-15°N band allowing for dynamical balance between the depth and tilt of the tropical thermocline and the model intrinsic biased wind. A sensitivity experiment to the latitudinal extension of no-nudging zone (1°S-1°N instead of 15°, hereafter referred to as NOEQ) has been carried out. In this paper, we concentrate our analyses on two specific regions: the tropical Pacific and the North Atlantic basins. In the Pacific, we show that the first year of the forecasts is characterized by a quasi-systematic excitation of El Niño-Southern Oscillation (ENSO) warm events whatever the starting dates. This, through ocean-to-atmosphere heat transfer materialized by diabatic heating

  10. Stochastic Ocean Eddy Perturbations in a Coupled General Circulation Model.

    NASA Astrophysics Data System (ADS)

    Howe, N.; Williams, P. D.; Gregory, J. M.; Smith, R. S.

    2014-12-01

    High-resolution ocean models, which are eddy permitting and resolving, require large computing resources to produce centuries worth of data. Also, some previous studies have suggested that increasing resolution does not necessarily solve the problem of unresolved scales, because it simply introduces a new set of unresolved scales. Applying stochastic parameterisations to ocean models is one solution that is expected to improve the representation of small-scale (eddy) effects without increasing run-time. Stochastic parameterisation has been shown to have an impact in atmosphere-only models and idealised ocean models, but has not previously been studied in ocean general circulation models. Here we apply simple stochastic perturbations to the ocean temperature and salinity tendencies in the low-resolution coupled climate model, FAMOUS. The stochastic perturbations are implemented according to T(t) = T(t-1) + (∆T(t) + ξ(t)), where T is temperature or salinity, ΔT is the corresponding deterministic increment in one time step, and ξ(t) is Gaussian noise. We use high-resolution HiGEM data coarse-grained to the FAMOUS grid to provide information about the magnitude and spatio-temporal correlation structure of the noise to be added to the lower resolution model. Here we present results of adding white and red noise, showing the impacts of an additive stochastic perturbation on mean climate state and variability in an AOGCM.

  11. Socioeconomic assessment of the proposed inactivation of the 5th Fighter Interceptor Squadron Minot Air Force Base, North Dakota

    SciTech Connect

    Kerley, C.R.; Sage, P.L.; Fichera, J.P.; Lufkin, P.; Stadelman, D.

    1988-12-01

    This assessment examines the potential socioeconomic impacts of inactivating the 5th Fighter Interceptor Squadron (FIS) at Minot Air Force Base (AFB), North Dakota. The study focuses on employment, population, and income impacts and estimates their effects on housing, community services, utilities, transportation, recreation and tourism, and public finance. This assessment is intended primarily for the use of Air Force and community planners concerned with the local consequences of the inactivation. 10 refs., 46 tabs.

  12. Coupled Dynamic Modeling to Assess Human Impact on Watershed Hydrology

    NASA Astrophysics Data System (ADS)

    Mohammed, I. N.; Tsai, Y.; Turnbull, S.; Bomblies, A.; Zia, A.

    2014-12-01

    Humans are intrinsic to the hydrologic system, both as agents of change and as beneficiaries of ecosystem services. This connection has been underappreciated in hydrology. We present a modeling linkage framework of an agent-based land use change model with a physical-based watershed model. The coupled model framework presented constitutes part of an integrated assessment model that is being developed to study human-ecosystem interaction in Missisquoi Bay, spanning Vermont and Québec, which is experiencing high concentrations of nutrients from the Missisquoi River watershed. The integrated assessment approach proposed is comprised of linking two simulation models: the Interactive Land-Use Transition Agent-Based Model (ILUTABM) and a physically based process model, the Regional Hydro-Ecological Simulation System (RHESSys). The ILUTABM treats both landscape and landowners as agents and simulates annual land-use patterns resulting from landowners annual land-use decisions and Best Management Practices (BMPs) adaptations to landowners utilities, land productivity and perceived impacts of floods. The Missisquoi River at Swanton watershed RHESSys model (drainage area of 2,200 km2) driven by climate data was first calibrated to daily streamflows and water quality sensor data at the watershed outlet. Simulated land-use patterns were then processed to drive the calibrated RHESSys model to obtain streamflow nutrient loading realizations. Nutrients loading realizations are then examined and routed back to the ILUTAB model to obtain public polices needed to manage the Missisquoi watershed as well as the Lake Champlain in general. We infer that the applicability of this approach can be generalized to other similar watersheds. Index Terms: 0402: Agricultural systems; 1800: Hydrology; 1803: Anthropogenic effects; 1834 Human impacts; 6344: System operation and management; 6334: Regional Planning

  13. Evolution of a Coupled Marine Ice Sheet - Sea Level Model

    NASA Astrophysics Data System (ADS)

    Gomez, N.; Pollard, D.; Mitrovica, J. X.; Huybers, P.; Clark, P. U.

    2011-12-01

    An instability mechanism is widely predicted for marine ice sheets resting upon reversed bed slopes. In this case, ice-sheet thinning or rising sea level is thought to lead to irreversible retreat of the grounding line. Previous analyses of marine ice-sheet stability have considered the influence of a sea-level perturbation on ice-sheet stability by assuming a geographically uniform, or eustatic, change in sea level. However, gravitational and deformational effects associated with changes in the volume of grounded ice lead to markedly non-uniform spatial patterns of sea-level change. In particular, a gravitationally self-consistent sea-level theory predicts a near-field sea-level change of opposite sign, and an order of magnitude greater amplitude, than would be predicted assuming eustasy. In recent work (Gomez et. al., Nature Geoscience, 2010), we highlighted the potential importance of this stabilizing sea-level mechanism by incorporating gravitationally self-consistent sea-level changes into a steady state ice sheet model. We extend this earlier analysis to investigate the influence of this stabilization mechanism on the timescale of ice-sheet retreat by coupling a sea-level model valid for a self-gravitating, viscoelastically deforming Earth to a 1D, dynamic marine ice sheet-shelf model. The evolution of the coupled model is explored for a suite of simulations in which we vary the bed slope and the forcing that initiates retreat. We find that the sea-level fall at the grounding line associated with a retreating ice sheet acts to slow the retreat; in simulations with shallow reversed bed slopes and/or small initial forcing, the drop in sea level can be sufficient to halt the retreat. The rate of sea-level change at the grounding line has an elastic component due to ongoing changes in ice-sheet geometry, and a viscous component due to past ice and ocean load changes. When the ice-sheet model is forced from steady state, on short timescales (< ~500 years), viscous

  14. Modelling couplings between reaction, fluid flow and deformation: Kinetics

    NASA Astrophysics Data System (ADS)

    Malvoisin, Benjamin; Podladchikov, Yury Y.; Connolly, James A. D.

    2016-04-01

    Mineral assemblages out of equilibrium are commonly found in metamorphic rocks testifying of the critical role of kinetics for metamorphic reactions. As experimentally determined reaction rates in fluid-saturated systems generally indicate complete reaction in less than several years, i.e. several orders of magnitude faster than field-based estimates, metamorphic reaction kinetics are generally thought to be controlled by transport rather than by processes at the mineral surface. However, some geological processes like earthquakes or slow-slip events have shorter characteristic timescales, and transport processes can be intimately related to mineral surface processes. Therefore, it is important to take into account the kinetics of mineral surface processes for modelling fluid/rock interactions. Here, a model coupling reaction, fluid flow and deformation was improved by introducing a delay in the achievement of equilibrium. The classical formalism for dissolution/precipitation reactions was used to consider the influence of the distance from equilibrium and of temperature on the reaction rate, and a dependence on porosity was introduced to model evolution of reacting surface area during reaction. The fitting of experimental data for three reactions typically occurring in metamorphic systems (serpentine dehydration, muscovite dehydration and calcite decarbonation) indicates a systematic faster kinetics close from equilibrium on the dehydration side than on the hydration side. This effect is amplified through the porosity term in the reaction rate since porosity is formed during dehydration. Numerical modelling indicates that this difference in reaction rate close from equilibrium plays a key role in microtextures formation. The developed model can be used in a wide variety of geological systems where couplings between reaction, deformation and fluid flow have to be considered.

  15. Summative assessment of 5th year medical students’ clinical reasoning by script concordance test: requirements and challenges

    PubMed Central

    2012-01-01

    Background The Script Concordance Test (SCT) has not been reported in summative assessment of students across the multiple domains of a medical curriculum. We report the steps used to build a test for summative assessment in a medical curriculum. Methods A 51 case, 158-question, multidisciplinary paper was constructed to assess clinical reasoning in 5th-year. 10–16 experts in each of 7 discipline-based reference panels answered questions on-line. A multidisciplinary group considered reference panel data and data from a volunteer group of 6th Years, who sat the same test, to determine the passing score for the 5th Years. Results The mean (SD) scores were 63.6 (7.6) and 68.6 (4.8) for the 6th Year (n = 23, alpha = 0.78) and and 5th Year (n = 132, alpha =0.62) groups (p < 0.05), respectively. The passing score was set at 4 SD from the expert mean. Four students failed. Conclusions The SCT may be a useful method to assess clinical reasoning in medical students in multidisciplinary summative assessments. Substantial investment in training of faculty and students and in the development of questions is required. PMID:22571351

  16. Emotional and Behavioral Disorders in 1.5th Generation, 2nd Generation Immigrant Children, and Foreign Adoptees.

    PubMed

    Tan, Tony Xing

    2016-10-01

    Existing theories (e.g., acculturative stress theory) cannot adequately explain why mental disorders in immigrants are less prevalent than in non-immigrants. In this paper, the culture-gene co-evolutionary theory of mental disorders was utilized to generate a novel hypothesis that connection to heritage culture reduces the risk for mental disorders in immigrant children. Four groups of children aged 2-17 years were identified from the 2007 United States National Survey of Children's Health: 1.5th generation immigrant children (n = 1378), 2nd generation immigrant children (n = 4194), foreign adoptees (n = 270), and non-immigrant children (n = 54,877). The 1.5th generation immigrant children's connection to their heritage culture is stronger than or similar to the 2nd generation immigrants, while the foreign adoptees have little connection to their birth culture. Controlling for age, sex, family type and SES, the odds for having ADD/ADHD, Conduct Disorder, Anxiety Disorder, and Depression diagnosis were the lowest for the 1.5th generation immigrant children, followed by the 2nd generation immigrant children and the foreign adoptees. The foreign adoptees and non-adopted children were similar in the odds of having these disorders. Connection to heritage culture might be the underlying mechanism that explained recent immigrants' lower rates of mental disorders. PMID:26972324

  17. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    SciTech Connect

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    example, the excavation-damaged zone (EDZ) near repository tunnels can modify local permeability (resulting from induced fractures), potentially leading to less confinement capability (Tsang et al., 2005). Because of clay's swelling and shrinkage behavior (depending on whether the clay is in imbibition or drainage processes), fracture properties in the EDZ are quite dynamic and evolve over time as hydromechanical conditions change. To understand and model the coupled processes and their impact on repository performance is critical for the defensible performance assessment of a clay repository. Within the Natural Barrier System (NBS) group of the Used Fuel Disposition (UFD) Campaign at DOE's Office of Nuclear Energy, LBNL's research activities have focused on understanding and modeling such coupled processes. LBNL provided a report in this April on literature survey of studies on coupled processes in clay repositories and identification of technical issues and knowledge gaps (Tsang et al., 2010). This report will document other LBNL research activities within the natural system work package, including the development of constitutive relationships for elastic deformation of clay rock (Section 2), a THM modeling study (Section 3) and a THC modeling study (Section 4). The purpose of the THM and THC modeling studies is to demonstrate the current modeling capabilities in dealing with coupled processes in a potential clay repository. In Section 5, we discuss potential future R&D work based on the identified knowledge gaps. The linkage between these activities and related FEPs is presented in Section 6.

  18. FAST TRACK COMMUNICATION Unexpected systematic degeneracy in a system of two coupled Gaudin models with homogeneous couplings

    NASA Astrophysics Data System (ADS)

    Erbe, B.; Schliemann, J.

    2010-12-01

    We report an unexpected systematic degeneracy between different multiplets in an inversion symmetric system of two coupled Gaudin models with homogeneous couplings, as occurring for example in the context of solid state quantum information processing. We construct the full degenerate subspace (being of macroscopic dimension), which turns out to lie in the kernel of the commutator between the two Gaudin models and the coupling term. Finally we investigate to what extent the degeneracy is related to the inversion symmetry of the system and find that indeed there is a large class of systems showing the same type of degeneracy.

  19. Modelling blast induced damage from a fully coupled explosive charge

    PubMed Central

    Onederra, Italo A.; Furtney, Jason K.; Sellers, Ewan; Iverson, Stephen

    2015-01-01

    This paper presents one of the latest developments in the blasting engineering modelling field—the Hybrid Stress Blasting Model (HSBM). HSBM includes a rock breakage engine to model detonation, wave propagation, rock fragmentation, and muck pile formation. Results from two controlled blasting experiments were used to evaluate the code’s ability to predict the extent of damage. Results indicate that the code is capable of adequately predicting both the extent and shape of the damage zone associated with the influence of point-of-initiation and free-face boundary conditions. Radial fractures extending towards a free face are apparent in the modelling output and matched those mapped after the experiment. In the stage 2 validation experiment, the maximum extent of visible damage was of the order of 1.45 m for the fully coupled 38-mm emulsion charge. Peak radial velocities were predicted within a relative difference of only 1.59% at the nearest history point at 0.3 m from the explosive charge. Discrepancies were larger further away from the charge, with relative differences of −22.4% and −42.9% at distances of 0.46 m and 0.61 m, respectively, meaning that the model overestimated particle velocities at these distances. This attenuation deficiency in the modelling produced an overestimation of the damage zone at the corner of the block due to excessive stress reflections. The extent of visible damage in the immediate vicinity of the blasthole adequately matched the measurements. PMID:26412978

  20. Coupling SWAT and ANN models for enhanced daily streamflow prediction

    NASA Astrophysics Data System (ADS)

    Noori, Navideh; Kalin, Latif

    2016-02-01

    To improve daily flow prediction in unmonitored watersheds a hybrid model was developed by combining a quasi-distributed watershed model and artificial neural network (ANN). Daily streamflow data from 29 nearby watersheds in and around the city of Atlanta, Southeastern United States, with leave-one-site-out jackknifing technique were used to build the flow predictive models during warm and cool seasons. Daily streamflow was first simulated with the Soil and Water Assessment Tool (SWAT) and then the SWAT simulated baseflow and stormflow were used as inputs to ANN. Out of the total 29 test watersheds, 62% and 83% of them had Nash-Sutcliffe values above 0.50 during the cool and warm seasons, respectively (considered good or better). As the percent forest cover or the size of test watershed increased, the performances of the models gradually decreased during both warm and cool seasons. This indicates that the developed models work better in urbanized watersheds. In addition, SWAT and SWAT Calibration Uncertainty Procedure (SWAT-CUP) program were run separately for each station to compare the flow prediction accuracy of the hybrid approach to SWAT. Only 31% of the sites during the calibration and 34% of validation runs had ENASH values ⩾0.50. This study showed that coupling ANN with semi-distributed models can lead to improved daily streamflow predictions in ungauged watersheds.

  1. A coupled energy transport and hydrological model for urban canopies

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Bou-Zeid, E.; Smith, J. A.

    2011-12-01

    Urban land-atmosphere interaction has been attracting more research efforts in order to understand the complex physics of flow and mass and heat transport in urban surfaces and the lower urban atmosphere. In this work, we developed and implemented a new physically-based single-layer urban canopy model, coupling the surface exchange of energy and the subsurface transport of water/soil moisture. The new model incorporates sub-facet heterogeneity for each urban surface (roof, wall or ground). This better simulates the energy transport in urban canopy layers, especially over low-intensity built (suburban type) terrains that include a significant fraction of vegetated surfaces. We implemented detailed urban hydrological models for both natural terrains (bare soil and vegetation) and porous engineered materials with water-holding capacity (concrete, gravel, etc). The skill of the new scheme was tested against experimental data collected through a wireless sensor network deployed over the campus of Princeton University. The model performance was found to be robust and insensitive to changes in weather conditions or seasonal variability. Predictions of the volumetric soil water content were also in good agreement with field measurements, highlighting the model capability of capturing subsurface water transport for urban lawns. The new model was also applied to a case study assessing different strategies, i.e. white versus green roofs, in the mitigation of urban heat island effect.

  2. Wealth distribution of simple exchange models coupled with extremal dynamics

    NASA Astrophysics Data System (ADS)

    Bagatella-Flores, N.; Rodríguez-Achach, M.; Coronel-Brizio, H. F.; Hernández-Montoya, A. R.

    2015-01-01

    Punctuated Equilibrium (PE) states that after long periods of evolutionary quiescence, species evolution can take place in short time intervals, where sudden differentiation makes new species emerge and some species extinct. In this paper, we introduce and study the effect of punctuated equilibrium on two different asset exchange models: the yard sale model (YS, winner gets a random fraction of a poorer player's wealth) and the theft and fraud model (TF, winner gets a random fraction of the loser's wealth). The resulting wealth distribution is characterized using the Gini index. In order to do this, we consider PE as a perturbation with probability ρ of being applied. We compare the resulting values of the Gini index at different increasing values of ρ in both models. We found that in the case of the TF model, the Gini index reduces as the perturbation ρ increases, not showing dependence with the agents number. While for YS we observe a phase transition which happens around ρc = 0.79. For perturbations ρ <ρc the Gini index reaches the value of one as time increases (an extreme wealth condensation state), whereas for perturbations greater than or equal to ρc the Gini index becomes different to one, avoiding the system reaches this extreme state. We show that both simple exchange models coupled with PE dynamics give more realistic results. In particular for YS, we observe a power low decay of wealth distribution.

  3. A fully coupled 2D model of equiaxed eutectic solidification

    SciTech Connect

    Charbon, Ch.; LeSar, R.

    1995-12-31

    We propose a model of equiaxed eutectic solidification that couples the macroscopic level of heat diffusion with the microscopic level of nucleation and growth of the eutectic grains. The heat equation with the source term corresponding to the latent heat release due to solidification is calculated numerically by means of an implicit finite difference method. In the time stepping scheme, the evolution of solid fraction is deduced from a stochastic model of nucleation and growth which uses the local temperature (interpolated from the FDM mesh) to determine the local grain density and the local growth rate. The solid-liquid interface of each grain is tracked by using a subdivision of each grain perimeter in a large number of sectors. The state of each sector (i.e. whether it is still in contact with the liquid or already captured by an other grain) and the increase of radius of each grain during one time step allows one to compute the increase of solid fraction. As for deterministic models, the results of the model are the evolution of temperature and of solid fraction at any point of the sample. Moreover the model provides a complete picture of the microstructure, thus not limiting the microstructural information to the average grain density but allowing one to compute any stereological value of interest. We apply the model to the solidification of gray cast iron.

  4. A coupled mechanical/hydrologic model for WIPP shaft seals

    SciTech Connect

    Ehgartner, B.

    1991-06-01

    Effective sealing of the Waste Isolation Pilot Plant (WIPP) shafts will be required to isolate defense-generated transuranic wastes from the accessible environment. Shafts penetrate water-bearing hard rock formations before entering a massive creeping-salt formation (Salado) where the WIPP is located. Short and long-term seals are planned for the shafts. Short-term seals, a composite of concrete and bentonite, will primarily be located in the hard rock formations separating the water-bearing zones from the Salado Formation. These seals will limit water flow to the underlying long-term seals in the Salado. The long-term seals will consist of lengthly segments of initially unsaturated crushed salt. Creep closure of the shaft will consolidate unsaturated crushed salt, thereby reducing its permeability. However, water passing through the upper short-term seals and brine inherent to the salt host rock itself will eventually saturate the crushed salt and consolidation could be inhibited. Before saturating, portions of the crushed salt in the shafts are expected to consolidate to a permeability equivalent to the salt host rock, thereby effectively isolating the waste from the overlying water-bearing formations. A phenomenological model is developed for the coupled mechanical/hydrologic behavior of sealed WIPP shafts. The model couples creep closure of the shaft, crushed salt consolidation, and the associated reduction in permeability with Darcy's law for saturated fluid flow to predict the overall permeability of the shaft seal system with time. 17 refs., 6 figs., 1 tab.

  5. Modeling of price and profit in coupled-ring networks

    NASA Astrophysics Data System (ADS)

    Tangmongkollert, Kittiwat; Suwanna, Sujin

    2016-06-01

    We study the behaviors of magnetization, price, and profit profiles in ring networks in the presence of the external magnetic field. The Ising model is used to determine the state of each node, which is mapped to the buy-or-sell state in a financial market, where +1 is identified as the buying state, and -1 as the selling state. Price and profit mechanisms are modeled based on the assumption that price should increase if demand is larger than supply, and it should decrease otherwise. We find that the magnetization can be induced between two rings via coupling links, where the induced magnetization strength depends on the number of the coupling links. Consequently, the price behaves linearly with time, where its rate of change depends on the magnetization. The profit grows like a quadratic polynomial with coefficients dependent on the magnetization. If two rings have opposite direction of net spins, the price flows in the direction of the majority spins, and the network with the minority spins gets a loss in profit.

  6. Modeling viscosity and diffusion of plasma mixtures across coupling regimes

    NASA Astrophysics Data System (ADS)

    Arnault, Philippe

    2014-10-01

    Viscosity and diffusion of plasma for pure elements and multicomponent mixtures are modeled from the high-temperature low-density weakly coupled regime to the low-temperature high-density strongly coupled regime. Thanks to an atom in jellium modeling, the effect of electron screening on the ion-ion interaction is incorporated through a self-consistent definition of the ionization. This defines an effective One Component Plasma, or an effective Binary Ionic Mixture, that is representative of the strength of the interaction. For the viscosity and the interdiffusion of mixtures, approximate kinetic expressions are supplemented by mixing laws applied to the excess viscosity and self-diffusion of pure elements. The comparisons with classical and quantum molecular dynamics results reveal deviations in the range 20--40% on average with almost no predictions further than a factor of 2 over many decades of variation. Applications in the inertial confinement fusion context could help in predicting the growth of hydrodynamic instabilities.

  7. Modeling Spin-Orbit Coupling in the Monohalocarbenes

    NASA Astrophysics Data System (ADS)

    Nyambo, Silver; Reid, Scott A.

    2012-06-01

    The monohalocarbenes CHX (X = F, Cl, Br, I) are model systems for examining carbene singlet-triplet energy gaps and spin-orbit coupling. In a series of studies, our group and others have used Single Vibronic Level (SVL) emission spectroscopy and Stimulated Emission Pumping (SEP) spectroscopy to probe the ground vibrational level structure in these carbenes, which has provided a wealth of spectroscopic information and clearly demonstrated the presence of perturbations involving the low-lying triplet state for X = Cl, Br, and I. To model these interactions in more detail, we used the structures, harmonic frequencies, and normal mode displacements from ab initio and DFT calculations to calculate the vibrational overlaps of the singlet and triplet state levels, incorporating the full effects of Dushinsky mixing. These results were then incorporated with the purely electronic spin-orbit matrix element into a matrix diagonalization routine which calculated the term energies of the mixed singlet-triplet levels, which were iteratively fit to the extensive experimental results from SVL emission and SEP spectroscopy for the carbenes and their deuterated isotopomers. These calculations have allowed many new assignments to be made, particularly for CHI, and provided improved estimates of the spin-orbit coupling matrix elements and singlet-triplet gaps.

  8. PREFACE: The 5th International Symposium in Quantum Theory and Symmetries (QTS5)

    NASA Astrophysics Data System (ADS)

    Arratia, O.; Calzada, J. A.; Gómez-Cubillo, F.; Negro, J.; del Olmo, M. A.

    2008-02-01

    This volume of Journal of Physics: Conference Series contains the Proceedings of the 5th International Symposium in Quantum Theory and Symmetries (QTS5), held in Valladolid, Spain, 22-28 July 2007. This is the fifth of a series of conferences previously held in Goslar (Germany) 1999, QTS1; Cracow (Poland) 2001, QTS2; Cincinnati (USA) 2003, QTS3, and Varna (Bulgaria) 2005, QTS4. The QTS5 symposium gathered 181 participants from 39 countries working in different fields on Theoretical Physics. The spirit of the QTS conference series is to join researchers in a wide variety of topics in Theoretical Physics, as a way to make accessible recent results and the new lines of different fields. The QTS5 conference offered the following list of topics: Symmetries in String Theory, Quantum Gravity and related Symmetries in Quantum Field Theories, Conformal and Related Field Theories, Lattice and Noncommutative Theories, Gauge Theories Quantum Computing, Information and Control Foundations of Quantum Theory Quantum Optics, Coherent States, Wigner Functions Dynamical and Integrable Systems Symmetries in Condensed Matter and Statistical Physics Symmetries in Particle Physics, Nuclear, Atomic and Molecular Nonlinear Quantum Mechanics Time Asymmetric Quantum Mechanics SUSY Quantum Mechanics, PT symmetries and pseudo-Hamiltonians Mathematical Methods for Symmetries and Quantum Theories Symmetries in Chemistry Biology and other Sciences Papers accepted for publication in the present issue are based on the contributions from the participants in the QTS5 conference after a peer review process. In addition, a special issue of Journal Physics A: Mathematical and Theoretical contains contributions from plenary speakers, some participants as well as contributions from other authors whose works fit into the topics of the conference. The organization of the conference had the following pattern. In the morning there were five plenary or general sessions for all the participants, which aimed to

  9. PREFACE: The 5th International Symposium on Quantum Theory and Symmetries (QTS5)

    NASA Astrophysics Data System (ADS)

    Gadella, M.; Izquierdo, J. M.; Kuru, S.; Negro, J.; del Olmo, M. A.

    2008-08-01

    This special issue of Journal of Physics A: Mathematical and Theoretical appears on the occasion of the 5th International Symposium on Quantum Theory and Symmetries (QTS5), held in Valladolid, Spain, from 22-28 July 2007. This is the fith in a series of conferences previously held in Goslar (Germany) 1999, QTS1; Cracow (Poland) 2001, QTS2; Cincinnati (USA) 2003, QTS3; and Varna (Bulgaria) 2005, QTS4. The QTS5 symposium gathered 181 participants from 39 countries working in different fields of theoretical physics. The spirit of the QTS conference series is to join researchers in a wide variety of topics in theoretical physics, as a way of making accessible recent results and the new lines of different fields. This is based on the feeling that it is good for a physicist to have a general overview as well as expertise in his/her own field. There are many other conferences devoted to specific topics, which are of interest to gain deeper insight in many technical aspects and that are quite suitable for discussions due to their small size. However, we believe that general conferences like this are interesting and worth keeping. We like the talks, in both plenary and parallel sessions, which are devoted to specific topics, to be prepared so as to be accessible to any researcher in any branch of theoretical physics. We think that this objective is compatible with rigour and high standards. As is well known, similar methods and techniques can be useful for many problems in different fields. We hope that this has been appreciated during the sessions of the QTS5 conference. The QTS5 conference offered the following list of topics: 1. Symmetries in string theory, quantum gravity and related topics 2. Symmetries in quantum field theories, conformal and related field theories, lattice and noncommutative theories, gauge theories 3.Quantum computing, information and control 4. Foundations of quantum theory 5. Quantum optics, coherent states, Wigner functions 6. Dynamical and

  10. PREFACE: The 5th International Symposium in Quantum Theory and Symmetries (QTS5)

    NASA Astrophysics Data System (ADS)

    Arratia, O.; Calzada, J. A.; Gómez-Cubillo, F.; Negro, J.; del Olmo, M. A.

    2008-02-01

    This volume of Journal of Physics: Conference Series contains the Proceedings of the 5th International Symposium in Quantum Theory and Symmetries (QTS5), held in Valladolid, Spain, 22-28 July 2007. This is the fifth of a series of conferences previously held in Goslar (Germany) 1999, QTS1; Cracow (Poland) 2001, QTS2; Cincinnati (USA) 2003, QTS3, and Varna (Bulgaria) 2005, QTS4. The QTS5 symposium gathered 181 participants from 39 countries working in different fields on Theoretical Physics. The spirit of the QTS conference series is to join researchers in a wide variety of topics in Theoretical Physics, as a way to make accessible recent results and the new lines of different fields. The QTS5 conference offered the following list of topics: Symmetries in String Theory, Quantum Gravity and related Symmetries in Quantum Field Theories, Conformal and Related Field Theories, Lattice and Noncommutative Theories, Gauge Theories Quantum Computing, Information and Control Foundations of Quantum Theory Quantum Optics, Coherent States, Wigner Functions Dynamical and Integrable Systems Symmetries in Condensed Matter and Statistical Physics Symmetries in Particle Physics, Nuclear, Atomic and Molecular Nonlinear Quantum Mechanics Time Asymmetric Quantum Mechanics SUSY Quantum Mechanics, PT symmetries and pseudo-Hamiltonians Mathematical Methods for Symmetries and Quantum Theories Symmetries in Chemistry Biology and other Sciences Papers accepted for publication in the present issue are based on the contributions from the participants in the QTS5 conference after a peer review process. In addition, a special issue of Journal Physics A: Mathematical and Theoretical contains contributions from plenary speakers, some participants as well as contributions from other authors whose works fit into the topics of the conference. The organization of the conference had the following pattern. In the morning there were five plenary or general sessions for all the participants, which aimed to

  11. rule, and in and models with FCNC quark couplings

    NASA Astrophysics Data System (ADS)

    Buras, Andrzej J.; De Fazio, Fulvia; Girrbach, Jennifer

    2014-07-01

    The experimental value for the isospin amplitude in decays has been successfully explained within the standard model (SM), both within the large approach to QCD and by QCD lattice calculations. On the other hand within the large approach the value of is by at least below the data. While this deficit could be the result of theoretical uncertainties in this approach and could be removed by future precise QCD lattice calculations, it cannot be excluded that the missing piece in comes from new physics (NP). We demonstrate that this deficit can be significantly softened by tree-level FCNC transitions mediated by a heavy colourless gauge boson with a flavour-violating left-handed coupling and an approximately universal flavour diagonal right-handed coupling to the quarks. The approximate flavour universality of the latter coupling assures negligible NP contributions to . This property, together with the breakdown of the GIM mechanisms at tree level, allows one to enhance significantly the contribution of the leading QCD-penguin operator to . A large fraction of the missing piece in the rule can be explained in this manner for in the reach of the LHC, while satisfying the constraints from , , , LEP-II and the LHC. The presence of a small right-handed flavour-violating coupling and of enhanced matrix elements of left-right operators allows one to satisfy simultaneously the constraints from and , although this requires some fine-tuning. We identify the quartic correlation between contributions to , , and . The tests of this proposal will require much improved evaluations of and within the SM, of as well as precise tree-level determinations of and . We present correlations between , and with and without the rule constraint and generalise the whole analysis to with colour () and with FCNC couplings. In the latter case no improvement on can be achieved without destroying the agreement of the SM with the data on . Moreover, this scenario is very tightly constrained by . On the

  12. Coupling MHD Simulations of CMEs to SEP Models

    NASA Astrophysics Data System (ADS)

    Torok, T.; Gorby, M.; Linker, J.; Schwadron, N.

    2015-12-01

    Large Solar Energetic Particle events (SEPs) are a main space weather hazard and extremely dangerous to astronauts and electronic equipmentin space. They are typically associated with fast Coronal Mass Ejections (CMEs). Recent results indicate that SEPs can be generated already inthe early phase of CME expansion low in the corona, but the underlyingphysical mechanisms are not yet well understood. State-of-the-artmagnetohydrodynamic (MHD) simulations of CME initiation and evolution,combined with numerical models of particle acceleration and propagation,provide a powerful tool to investigate these mechanisms. In this talk, we present recent developments in the coupling of CORHEL/MAS thermodynamicMHD simulations of fast CMEs to the EPREM particle code, and we discuss the insights that can be gained from such a combined modeling approach.

  13. Coupling multi-physics models to cardiac mechanics.

    PubMed

    Nordsletten, D A; Niederer, S A; Nash, M P; Hunter, P J; Smith, N P

    2011-01-01

    We outline and review the mathematical framework for representing mechanical deformation and contraction of the cardiac ventricles, and how this behaviour integrates with other processes crucial for understanding and modelling heart function. Building on general conservation principles of space, mass and momentum, we introduce an arbitrary Eulerian-Lagrangian framework governing the behaviour of both fluid and solid components. Exploiting the natural alignment of cardiac mechanical properties with the tissue microstructure, finite deformation measures and myocardial constitutive relations are referred to embedded structural axes. Coupling approaches for solving this large deformation mechanics framework with three dimensional fluid flow, coronary hemodynamics and electrical activation are described. We also discuss the potential of cardiac mechanics modelling for clinical applications. PMID:19917304

  14. Representing Icebergs In A Fully Coupled Climate Model

    NASA Astrophysics Data System (ADS)

    Bügelmayer, Marianne; Roche, Didier; Renssen, Hans

    2014-05-01

    Changes in the global climate during past and current times strongly impact the Polar Regions, which in turn affect the global climate due to several mechanisms, such as albedo, topography, ablation and ice discharge. Icebergs are an important part of the climate system as they interact with the ocean, atmosphere and cryosphere. Several approaches have been taken to incorporate iceberg calving into numerical models under different climate forcings. The studies done so far have in common that the icebergs were moved by reconstructed or modelled forcing fields and that the initial size distribution of the icebergs was prescribed according to present day observations. Hence, uncertainties in the forcing fields and in the parameterization of the iceberg size may alter the results. To investigate the impact of the background forcing (atmosphere, ocean) and the pre-defined size distribution on the icebergs and consequently on the Northern hemisphere climate and the Greenland ice sheet, we have coupled an earth system model of intermediate complexity (iLOVECLIM, Roche et al., 2013) to an ice sheet/ice shelf model (GRISLI, Ritz et al., 2001) and an iceberg module (Jongma et al., 2009; Bügelmayer et al., 2014). Using this set-up, we performed 15 sensitivity experiments that differ in the applied forcing (atmosphere, ocean), the applied boundary conditions (pre-industrial, 4xCO2, 1/4 x CO2) and the initial size distribution of the icebergs. In the presented study only the Greenland ice sheet is considered. We find that, under pre-industrial conditions, the atmospheric forcing pushes the icebergs further away from their calving sites and further into the North Atlantic, whereas the ocean currents transport the bergs along the Greenland coast and southward along the Canadian coast. Although the purely atmospheric-forced bergs cause warmer oceanic conditions than the oceanic-driven bergs, the overall effect on climate and the resulting ice sheet due to variations in the

  15. Seawater intrusions: Coupling groundwater model and geophysical data

    NASA Astrophysics Data System (ADS)

    Steklova, K.; Haber, E.; Cockett, R.

    2012-12-01

    The process of seawater intrusions into freshwater aquifers occurs naturally, but also as a result of increased groundwater extraction. Different types of models to capture this complex process involving density driven flow and variable boundary conditions have already been proposed and implemented. However, many fewer studies were done in groundwater management planning, for example how to adjust the future groundwater extraction or injection rates with respect to saltwater intrusions occurrence. Geophysical methods (e.g. DC resistivity) offer a good alternative to standard hydrological measurement techniques which need to deal with the miscibility of both freshwater and saltwater and only scarce observation points. The resistivity survey can provide 3D data at lower cost, however the precision depends on the reference models and often decreases with depth. Therefore we suggest an optimization framework which links the hydrogeological model with geophysical datasets. The dynamics of the system is represented by a 3D model for transient groundwater flow in a confined aquifer based on discretized flow and solute mass balance equations. To overcome the difficulty of coupled nonlinear governing equations a semi - Lagrangian method is implemented for the transport equation. This enables to choose arbitrarily large time step without losing stability. For the geophysical forward and inverse problem RESINVM3D package is used. Once the coupled optimization framework is used for many time steps it leads to an optimal control problem. Kalman filtering techniques are often used for such problems, after each time step the optimal state estimates are found based on the system dynamics and observations which are in this case provided by geophysical data. For the variable density flow the process dynamic is nonlinear, in such cases the KF state estimates derivation assumes that the deviation from linearity is of a first order. For the seawater intrusions, where the concentration

  16. Coupled Modeling of Fault Poromechanics During Geologic CO2 Storage

    NASA Astrophysics Data System (ADS)

    Jha, B.; Hager, B. H.; Juanes, R.

    2012-12-01

    Perhaps the most pressing current debate surrounding carbon capture and storage (CCS) revolves around the pressure limitations on geologic storage [Szulczewski et al., 2012]. Overpressures due to CO2 injection could fracture the caprock [Birkholzer and Zhou, 2009], trigger earthquakes [Cappa and Rutqvist, 2011], and potentially compromise the caprock by activating faults [Zoback and Gorelick, 2012]. While an alarmist view of these issues [Zoback and Gorelick, 2012] appears unwarranted, it seems clear that addressing the coupled processes of CO2 injection and fault poromechanics constitutes a pressing challenge for CCS. More generally, the fundamental link between earthquakes and groundwater flow is a first-order geoscience problem. Despite the interest that this issue has received in recent times, many aspects remain poorly understood, from the physics of the problem to the ability to perform credible fully-coupled simulations. Here, we advance our current simulation technology for forecasting fault slip and fault activation from fluid injection and withdrawal at depth. We present the development and application of a coupled multiphase-flow and reservoir-geomechanics simulator able to model the poromechanics of faults. We use a recently-discovered operator split, the fixed-stress split [Kim et al., 2011], to obtain an unconditionally-stable sequential iterative scheme for the simulation of multiphase flow and geomechanics. The geomechanics code PyLith [Aagaard et al., 2011] permits simulating faults as surfaces of discontinuity. We use the rigorous nonlinear formulation of coupled geomechanics, in which the variation in the fluid mass of each phase is tracked [Coussy, 1995]. Our approach allows us to model strong capillarity and compressibility effects, which can be important in the context of CO2 injection. We present results from several synthetic case studies to highlight the main features of our simulator, and to perform a preliminary risk assessment of leakage

  17. A Coupled Surface/Subsurface Model for Hydrological Drought Investigations

    NASA Astrophysics Data System (ADS)

    Musuuza, J. L.; Kumar, R.; Samaniego, L. E.; Fischer, T.; Kolditz, O.; Attinger, S.

    2013-12-01

    Hydrological droughts occur when storage in the ground and surface-water bodies falls below statistical average. Due to the inclusion of regional groundwater, hydrological droughts evolve relatively slowly. The atmospheric and surface components of the hydrological cycle have been widely studied, are well understood, and their prognoses are fairly accurate. In large-scale land surface models on the other hand, subsurface (groundwater) flow processes are usually assumed unidirectional and limited to the vertically-downward percolation and the horizontal runoffs. The vertical feedback from groundwater to the unsaturated zone as well as the groundwater recharge from surface waters are usually misrepresented, resulting in poor model performance during low-flow periods. The feedback is important during meteorological droughts because it replenishes soil moisture from ground- and surface water, thereby delaying the onset of agricultural droughts. If sustained for long periods however, the depletion can significantly reduce surface and subsurface storage and lead to severe hydrological droughts. We hypothesise that an explicit incorporation of the groundwater component into an existing land surface model would lead to better representation of low flows, which is critical for drought analyses. It would also improve the model performance during low-flow periods. For this purpose, we coupled the process-based mHM surface model (Samaniego et al. 2010) with MODFLOW (Harbaugh 2005) to analyse droughts in the Unstrut catchment, one of the tributaries of the Elbe. The catchment is located in one of the most drought-prone areas of Germany. We present results for stand-alone and coupled mHM simulations for the period 1970-2000. References Arlen W. Harbaugh. MODFLOW-2005, The U.S. Geological Survey Modular Ground-water Model-the Ground-water Flow Process, chapter Modelling techniques, sec. A. Ground water, pages 1:1-9:62. USGS, 2005. Luis Samaniego, Rohini Kumar, and Sabine Attinger

  18. Developing hillslope-based catchment models: coupling Boussinesq and regional scale flow models

    NASA Astrophysics Data System (ADS)

    Broda, S.; Paniconi, C.; Larocque, M.

    2009-04-01

    The gaining recognition of hillslopes as fundamental building blocks in watershed hydrology makes them appealing for incorporation into larger scale river basin models. Hillslope processes are commonly simulated by means of the Boussinesq equation and are therefore applicable to single layer flow systems only. Two coupled models are presented to simulate both local hillslope scale and regional scale groundwater flow: 1) the hillslope-storage Boussinesq (hsB) model representing unconfined flow and a steady, analytic element model representing transient regional deep groundwater flow through a succession of steady state stress periods over many hydrological years, and 2) the hsB model and a newly developed analytical solution for 1D transient confined groundwater flow. Recharge zones are defined by means of irregular geometric domains, capturing the plan form geometry of the hillslopes. Lateral flows are calculated in inclined aquifers of homogeneous thickness. Tests are conducted on i) single hillslopes of varying inclination and plan form geometry and ii) a laboratory watershed, and heads and baseflows are compared to the results from a fully coupled 3D Richards equation model. Both approaches presented provide reasonable heads and fluxes for a range of hillslope properties in comparison to the benchmark model, and are promising approaches, applicable to a range of land surface models that lack a detailed description of subsurface flow. However the coupled hsB/1D-analytical model is numerically more stable and computationally more efficient than the coupled hsB/analytic element model.

  19. Coupled thermo-hydro-chemical models of swelling bentonites

    NASA Astrophysics Data System (ADS)

    Samper, Javier; Mon, Alba; Zheng, Liange; Montenegro, Luis; Naves, Acacia; Pisani, Bruno

    2014-05-01

    The disposal of radioactive waste in deep geological repositories is based on the multibarrier concept of retention of the waste by a combination of engineered and geological barriers. The engineered barrier system (EBS) includes the solid conditioned waste-form, the waste container, the buffer made of materials such as clay, grout or crushed rock that separate the waste package from the host rock and the tunnel linings and supports. The geological barrier supports the engineered system and provides stability over the long term during which time radioactive decay reduces the levels of radioactivity. The strong interplays among thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration, thermal and solute transport stages of the engineered barrier system (EBS) of a radioactive waste repository call for coupled THMC models for the metallic overpack, the unsaturated compacted bentonite and the concrete liner. Conceptual and numerical coupled THMC models of the EBS have been developed, which have been implemented in INVERSE-FADES-CORE. Chemical reactions are coupled to the hydrodynamic processes through chemical osmosis (C-H coupling) while bentonite swelling affects solute transport via changes in bentonite porosity changes (M-H coupling). Here we present THMC models of heating and hydration laboratory experiments performed by CIEMAT (Madrid, Spain) on compacted FEBEX bentonite and numerical models for the long-term evolution of the EBS for 1 Ma. The changes in porosity caused by swelling are more important than those produced by the chemical reactions during the early evolution of the EBS (t < 100 years). For longer times, however, the changes in porosity induced by the dissolution/precipitation reactions are more relevant due to: 1) The effect of iron mineral phases (corrosion products) released by the corrosion of the carbon steel canister; and 2) The hyper alkaline plume produced by the concrete liner. Numerical results show that

  20. Double Layers: Potential Formation and Related Nonlinear Phenomena in Plasmas: Proceedings of the 5th Symposium

    NASA Astrophysics Data System (ADS)

    Iizuka, S.

    1998-02-01

    The Table of Contents for the book is as follows: * PREFACE * INTERNATIONAL SCIENTIFIC COMMITTEE * LOCAL ORGANIZING COMMITTEE AT TOHOKU UNIVERSITY * CHAPTER 1: DOUBLE LAYERS, SHEATHS, AND POTENTIAL STRUCTURES * 1.1 Double Layers * On Fluid Models of Stationary, Acoustic Double Layers (Invited) * Particle Simulation of Double Layer (Invited) * Space-Time Dependence of Non-Steady Double Layers * The Role of Low Energy Electrons for the Generation of Anode Double Layers in Glow Discharges * Arbitrary Amplitude Ion-Acoustic Double Layers in a Dusty Plasma * 1.2 Sheaths * Bounded Plasma Edge Physics as Observed from Simulations in 1D and 2D (Invited) * Control of RF Sheath Structure in RF Diode Discharge * Observation of Density Gradients with Fine Structures and Low Frequency Wave Excitation at the Plasma-Sheath Boundary * Double Sheath Associated with an Electron Emission to a Plasma Containing Negative Ions * Sheath Edge and Floating Potential for Multi-Species Plasmas Including Dust Particles * 1.3 Potential Structures and Oscillations * Potential Structure Formed at a Constriction of a DC He Positive Column and its Coupling with Ionization Wave * Potential Structure in a New RF Magnetron Device with a Hollow Electrode * Potential Disruption in a RF Afterglow Electronegative Plasma * Potential Oscillation in a Strongly Asymmetry RF Discharge Containing Negative Ions * Effects of External Potential Control on Coulomb Dust Behavior * Potential Structure of Carbon Arc Discharge for High-Yield Fullerenes Formation * Control of Axial and Radial Potential Profiles in Tandem Mirrors (Invited) * CHAPTER 2: FIELD-ALIGNED ELECTRIC FIELDS AND RELATED PARTICLE ACCELERATIONS * 2.1 Field-Aligned Potential Formation * Formation of Large Potential Difference in a Plasma Flow along Converging Magnetic Field Lines (Invited) * Presheath Formation in front of an Oblique End-Plate in a Magnetized Sheet Plasma * Plasma Potential Formation Due to ECRH in a Magnetic Well * Electrostatic

  1. Teacher and Parent Views on the Instruction of 5th Grade Students by Branch Teachers in the 4+4+4 Education System

    ERIC Educational Resources Information Center

    Yildizhan, Yusuf Hayri

    2015-01-01

    The objective of this study is to examine the teacher and parent views on the instruction of 5th grade students by branch teachers. This study is designed according to the phenomenology design and uses qualitative data. In order to collect data, open-ended questions were asked to 18 teachers and 16 parents of 5th grade students on the subject, and…

  2. Using Community-based Participatory Research to Adapt keepin’ it REAL: Creating a Socially, Developmentally, and Academically Appropriate Prevention Curriculum for 5th Graders

    PubMed Central

    Harthun, Mary L.; Dustman, Patricia A.; Reeves, Leslie J.; Marsiglia, Flavio F.; Hecht, Michael L.

    2010-01-01

    This paper reports on a process in which program designers, classroom teachers, and students worked together to adapt the 7th grade “keepin’ it REAL” prevention curriculum to a developmentally, socially, and academically appropriate curriculum for 5th graders. A Community-Based Participatory Research methodology (CBPR), combined with a 9-step adaptation model, emphasized a collaborative approach, both transformative and empowering. Essential adaptation elements were the Risk-to-Resiliency Continuum; the teaching of a wide range of skills including risk assessment, decision making, and resistance strategies; and, maintaining the theoretical grounding of Narrative Theory, Communication Competence, and Focus Theory of Norms. This paper describes how CBPR methodology can be conducted successfully while focusing on sustained theoretical grounding and effective research practices in a school-based setting. PMID:21057596

  3. Affine group formulation of the Standard Model coupled to gravity

    SciTech Connect

    Chou, Ching-Yi; Ita, Eyo; Soo, Chopin

    2014-04-15

    In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauder’s affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant Λ, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and Yang–Mills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the Yang–Mills and Higgs energy densities, are composed with York’s integrated time functional. The result, when combined with the imaginary part of the Chern–Simons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: •Wheeler–DeWitt equation (WDW) quantized as affine algebra, realizing Klauder’s program. •WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. •WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. •Constructed a family of physical states for the full, coupled theory via affine coherent states. •Fundamental uncertainty relation, predicated on non-vanishing cosmological constant.

  4. Decadal climate predictions with an high resolution coupled model

    NASA Astrophysics Data System (ADS)

    Monerie, P. A.; Valcke, S.; Moine, M. P.; Maisonnave, E.; Coquart, L.; Cassou, C.; Terray, L.

    2014-12-01

    We analyze the decadal prediction skill of sea surface temperature variability with a high resolution coupled Ocean-Atmosphere General Circulation Model (OAGCM). The HR CERFACS was developed at the CERFACS (Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique) laboratory in the framework of the EU-FP7 SPECS (Seasonal-to-decadal climate Predictions for the improvement of European Climate Services) project in order to address the question of decadal predictability with the use of a high spatial resolution. The atmospheric model is ARPEGE/IFS with a T359 spectral truncature and the oceanic model is NEMO at 0.25° resolution including the LIM2 sea ice model. Each hindcasts consist of a 10-members ensemble integrated over a 10-years period. These hindcasts are full-field initialized every year from 1993 to 2009 and initial oceanic state is given by the GLORYS2V1 (0.25° resolution) sea-surface temperatures. Members of a given ensemble (one initialization date) are generated by perturbations of the atmospheric initial conditions. We study the predictability of the global sea-surface temperature focusing on the Atlantic Multidecadal Oscillation (AMO), the Pacific Decadal Oscillation (PDO), the North Atlantic Subpolar Gyre (SPG) and the El-Nino Southern Oscillation (ENSO). We also investigate the prediction skill of the Atlantic Meridional Overturning Circulation (AMOC).

  5. Coupled model of physical and biological processes affecting maize pollination

    NASA Astrophysics Data System (ADS)

    Arritt, R.; Westgate, M.; Riese, J.; Falk, M.; Takle, E.

    2003-04-01

    Controversy over the use of genetically modified (GM) crops has led to increased interest in evaluating and controlling the potential for inadvertent outcrossing in open-pollinated crops such as maize. In response to this problem we have developed a Lagrangian model of pollen dispersion as a component of a coupled end-to-end (anther to ear) physical-biological model of maize pollination. The Lagrangian method is adopted because of its generality and flexibility: first, the method readily accommodates flow fields of arbitrary complexity; second, each element of the material being transported can be identified by its source, time of release, or other properties of interest. The latter allows pollen viability to be estimated as a function of such factors as travel time, temperature, and relative humidity, so that the physical effects of airflow and turbulence on pollen dispersion can be considered together with the biological aspects of pollen release and viability. Predicted dispersion of pollen compares well both to observations and to results from a simpler Gaussian plume model. Ability of the Lagrangian model to handle complex air flows is demonstrated by application to pollen dispersion in the vicinity of an agricultural shelter belt. We also show results indicating that pollen viability can be quantified by an "aging function" that accounts for temperature, humidity, and time of exposure.

  6. Coupled Thermal-Chemical-Mechanical Modeling of Validation Cookoff Experiments

    SciTech Connect

    ERIKSON,WILLIAM W.; SCHMITT,ROBERT G.; ATWOOD,A.I.; CURRAN,P.D.

    2000-11-27

    The cookoff of energetic materials involves the combined effects of several physical and chemical processes. These processes include heat transfer, chemical decomposition, and mechanical response. The interaction and coupling between these processes influence both the time-to-event and the violence of reaction. The prediction of the behavior of explosives during cookoff, particularly with respect to reaction violence, is a challenging task. To this end, a joint DoD/DOE program has been initiated to develop models for cookoff, and to perform experiments to validate those models. In this paper, a series of cookoff analyses are presented and compared with data from a number of experiments for the aluminized, RDX-based, Navy explosive PBXN-109. The traditional thermal-chemical analysis is used to calculate time-to-event and characterize the heat transfer and boundary conditions. A reaction mechanism based on Tarver and McGuire's work on RDX{sup 2} was adjusted to match the spherical one-dimensional time-to-explosion data. The predicted time-to-event using this reaction mechanism compares favorably with the validation tests. Coupled thermal-chemical-mechanical analysis is used to calculate the mechanical response of the confinement and the energetic material state prior to ignition. The predicted state of the material includes the temperature, stress-field, porosity, and extent of reaction. There is little experimental data for comparison to these calculations. The hoop strain in the confining steel tube gives an estimation of the radial stress in the explosive. The inferred pressure from the measured hoop strain and calculated radial stress agree qualitatively. However, validation of the mechanical response model and the chemical reaction mechanism requires more data. A post-ignition burn dynamics model was applied to calculate the confinement dynamics. The burn dynamics calculations suffer from a lack of characterization of the confinement for the flaw

  7. Coupled geophysical-hydrological modeling of controlled NAPL spill

    NASA Astrophysics Data System (ADS)

    Kowalsky, M. B.; Majer, E.; Peterson, J. E.; Finsterle, S.; Mazzella, A.

    2006-12-01

    Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data interpretation. Combining multiple geophysical data types and incorporating constraints from hydrological models will potentially decrease the non-uniqueness in data interpretation and aid in site characterization. Large-scale laboratory experiments have been conducted over several years to evaluate the use of various geophysical methods, including ground-penetrating radar (GPR), seismic, and electrical methods, for monitoring controlled spills of tetrachloroethylene (PCE), a hazardous industrial solvent that is pervasive in the subsurface. In the current study, we consider an experiment in which PCE was introduced into a large tank containing a heterogeneous distribution of sand and clay mixtures, and allowed to migrate while time-lapse geophysical data were collected. We consider two approaches for interpreting the surface GPR and crosswell seismic data. The first approach involves (a) waveform inversion of the surface GPR data using a non-gradient based optimization algorithm to estimate the dielectric constant distributions and (b) conversion of crosswell seismic travel times to acoustic velocity distributions; the dielectric constant and acoustic velocity distributions are then related to NAPL saturation using appropriate petrophysical models. The second approach takes advantage of a recently developed framework for coupled hydrological-geophysical modeling, providing a hydrological constraint on interpretation of the geophysical data and additionally resulting in quantitative estimates of the most relevant hydrological parameters that determine NAPL behavior in the system. Specifically, we simulate NAPL migration using the multiphase multicomponent flow simulator TOUGH2 with a 2-D radial

  8. The 5th Annual NASA Spacecraft Control Laboratory Experiment (SCOLE) Workshop, part 2

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr. (Compiler)

    1990-01-01

    A collection of papers from the workshop are presented. The topics addressed include: the modeling, systems identification, and control synthesis for the Spacecraft Control Laboratory Experiment (SCOLE) configuration.

  9. Stepwise calibration procedure for regional coupled hydrological-hydrogeological models

    NASA Astrophysics Data System (ADS)

    Labarthe, Baptiste; Abasq, Lena; de Fouquet, Chantal; Flipo, Nicolas

    2014-05-01

    Stream-aquifer interaction is a complex process depending on regional and local processes. Indeed, the groundwater component of hydrosystem and large scale heterogeneities control the regional flows towards the alluvial plains and the rivers. In second instance, the local distribution of the stream bed permeabilities controls the dynamics of stream-aquifer water fluxes within the alluvial plain, and therefore the near-river piezometric head distribution. In order to better understand the water circulation and pollutant transport in watersheds, the integration of these multi-dimensional processes in modelling platform has to be performed. Thus, the nested interfaces concept in continental hydrosystem modelling (where regional fluxes, simulated by large scale models, are imposed at local stream-aquifer interfaces) has been presented in Flipo et al (2014). This concept has been implemented in EauDyssée modelling platform for a large alluvial plain model (900km2) part of a 11000km2 multi-layer aquifer system, located in the Seine basin (France). The hydrosystem modelling platform is composed of four spatially distributed modules (Surface, Sub-surface, River and Groundwater), corresponding to four components of the terrestrial water cycle. Considering the large number of parameters to be inferred simultaneously, the calibration process of coupled models is highly computationally demanding and therefore hardly applicable to a real case study of 10000km2. In order to improve the efficiency of the calibration process, a stepwise calibration procedure is proposed. The stepwise methodology involves determining optimal parameters of all components of the coupled model, to provide a near optimum prior information for the global calibration. It starts with the surface component parameters calibration. The surface parameters are optimised based on the comparison between simulated and observed discharges (or filtered discharges) at various locations. Once the surface parameters

  10. Properties of Coupled Oscillator Model for Bidirectional Associative Memory

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Satoshi

    2016-08-01

    In this study, we consider the stationary state and dynamical properties of a coupled oscillator model for bidirectional associative memory. For the stationary state, we apply the replica method to obtain self-consistent order parameter equations. The theoretical results for the storage capacity and overlap agree well with the numerical simulation. For the retrieval process, we apply statistical neurodynamics to include temporal noise correlations. For the successful retrieval process, the theoretical result obtained with the fourth-order approximation qualitatively agrees with the numerical simulation. However, for the unsuccessful retrieval process, higher-order noise correlations suppress severely; therefore, the maximum value of the overlap and the relaxation time are smaller than those of the numerical simulation. The reasons for the discrepancies between the theoretical result and numerical simulation, and the validity of our analysis are discussed.

  11. Multi-Scale Coupling in Ocean and Climate Modeling

    SciTech Connect

    Zhengyu Liu, Leslie Smith

    2009-08-14

    We have made significant progress on several projects aimed at understanding multi-scale dynamics in geophysical flows. Large-scale flows in the atmosphere and ocean are influenced by stable density stratification and rotation. The presence of stratification and rotation has important consequences through (i) the conservation of potential vorticity q = {omega} {center_dot} {del} {rho}, where {omega} is the total vorticity and {rho} is the density, and (ii) the existence of waves that affect the redistribution of energy from a given disturbance to the flow. Our research is centered on quantifying the effects of potential vorticity conservation and of wave interactions for the coupling of disparate time and space scales in the oceans and the atmosphere. Ultimately we expect the work to help improve predictive capabilities of atmosphere, ocean and climate modelers. The main findings of our research projects are described.

  12. Finite Hypernuclei in the Latest Quark-Meson Coupling Model

    SciTech Connect

    Pierre A. M. Guichon; Anthony W. Thomas; Kazuo Tsushima

    2007-12-12

    The most recent development of the quark-meson coupling (QMC) model, in which the effect of the mean scalar field in-medium on the hyperfine interaction is also included self-consistently, is used to compute the properties of finite hypernuclei. The calculations for $\\Lambda$ and $\\Xi$ hypernuclei are of comparable quality to earlier QMC results without the additional parameter needed there. Even more significantly, the additional repulsion associated with the increased hyperfine interaction in-medium completely changes the predictions for $\\Sigma$ hypernuclei. Whereas in the earlier work they were bound by an amount similar to $\\Lambda$ hypernuclei, here they are unbound, in qualitative agreement with the experimental absence of such states. The equivalent non-relativistic potential felt by the $\\Sigma$ is repulsive inside the nuclear interior and weakly attractive in the nuclear surface, as suggested by the analysis of $\\Sigma$-atoms.

  13. Acoustically-coupled flow-induced vibration of a computational vocal fold model

    PubMed Central

    Daily, David Jesse; Thomson, Scott L.

    2012-01-01

    The flow-induced vibration of synthetic vocal fold models has been previously observed to be acoustically-coupled with upstream flow supply tubes. This phenomenon was investigated using a finite element model that included flow–structure–acoustic interactions. The length of the upstream duct was varied to explore the coupling between model vibration and subglottal acoustics. Incompressible and slightly compressible flow models were tested. The slightly compressible model exhibited acoustic coupling between fluid and solid domains in a manner consistent with experimental observations, whereas the incompressible model did not, showing the slightly compressible approach to be suitable for simulating acoustically-coupled vocal fold model flow-induced vibration. PMID:23585700

  14. Acoustically-coupled flow-induced vibration of a computational vocal fold model.

    PubMed

    Daily, David Jesse; Thomson, Scott L

    2013-01-15

    The flow-induced vibration of synthetic vocal fold models has been previously observed to be acoustically-coupled with upstream flow supply tubes. This phenomenon was investigated using a finite element model that included flow-structure-acoustic interactions. The length of the upstream duct was varied to explore the coupling between model vibration and subglottal acoustics. Incompressible and slightly compressible flow models were tested. The slightly compressible model exhibited acoustic coupling between fluid and solid domains in a manner consistent with experimental observations, whereas the incompressible model did not, showing the slightly compressible approach to be suitable for simulating acoustically-coupled vocal fold model flow-induced vibration. PMID:23585700

  15. A Coupled Multiscale Model of Texture Evolution and Plastic Anisotropy

    NASA Astrophysics Data System (ADS)

    Gawad, J.; Van Bael, A.; Yerra, S. K.; Samaey, G.; Van Houtte, P.; Roose, D.

    2010-06-01

    In this paper we present a multiscale model of a plastic deformation process in which the anisotropy of plastic properties is related to the evolution of the crystallographic texture. The model spans several length scales from the macroscopic deformation of the workpiece to the microscale interactions between individual grains in a polycrystalline material. The macroscopic behaviour of the material is described by means of a Finite Element (FE) model. Plastic anisotropy is taken into account in a constitutive law, based on the concept of a plastic potential in strain rate space. The coefficients of a sixth-order Facet equation are determined using the Taylor theory, provided that the current crystallographic texture at a given FE integration point is known. Texture evolution in the FE integration points is predicted by an ALAMEL micromechanical model. Mutual interactions between coarse and fine scale are inherent in the physics of the deformation process. These dependencies are taken into account by full bidirectional coupling in the model. Therefore, the plastic deformation influences the crystallographic texture and the evolution of the texture induces anisotropy of the macroscopic deformation. The presented approach enables an adaptive texture and yield surface update scheme with respect to the local plastic deformation in the FE integration points. Additionally, the computational cost related to the updates of the constitutive law is reduced by application of parallel computing techniques. Suitability of on-demand computing for this computational problem is discussed. The parallelisation strategy addresses both distributed memory and shared memory architectures. The cup drawing process has been simulated using the multiscale model outlined above. The discussion of results includes the analysis of the planar anisotropy in the cup and the influence of complex deformation path on texture development. Evolution of texture at selected material points is assessed as

  16. Long-Term Variability in a Coupled Atmosphere Biosphere Model.

    NASA Astrophysics Data System (ADS)

    Delire, Christine; Foley, Jonathan A.; Thompson, Starley

    2004-10-01

    A fully coupled atmosphere biosphere model, version 3 of the NCAR Community Climate Model (CCM3) and the Integrated Biosphere Simulator (IBIS), is used to illustrate how vegetation dynamics may be capable of producing long-term variability in the climate system, particularly through the hydrologic cycle and precipitation. Two simulations of the global climate are conducted with fixed climatological sea surface temperatures: one including vegetation as a dynamic boundary condition, and the other keeping vegetation cover fixed. A comparison of the precipitation power spectra over land from these two simulations shows that dynamic interactions between the atmosphere and vegetation enhance precipitation variability at time scales from a decade to a century, while damping variability at shorter time scales.In these simulations, the two-way coupling between the atmosphere and the dynamic vegetation cover introduces persistent precipitation anomalies in several ecological transition zones: between forest and grasslands in the North American midwest, in southern Africa, and at the southern limit of the tropical forest in the Amazon basin, and between savanna and desert in the Sahel, Australia, and portions of the Arabian Peninsula. These regions contribute most to the long-term variability of the atmosphere vegetation system.Slow changes in the vegetation cover, resulting from a “red noise” integration of high-frequency atmospheric variability, are responsible for generating this long-term variability. Lead and lag correlation between precipitation and vegetation leaf area index (LAI) shows that LAI influences precipitation in the following years, and vice versa. A mechanism involving changes in LAI resulting in albedo, roughness, and evapotranspiration changes is proposed.


  17. Fully Coupled Well Models for Fluid Injection and Production

    SciTech Connect

    White, Mark D.; Bacon, Diana H.; White, Signe K.; Zhang, Z. F.

    2013-08-05

    these equations varies from zero coupling to full coupling. In this paper we describe a fully coupled solution approach for well model that allows for a flexible well trajectory and screened interval within a structured hexahedral computational grid. In this scheme the nonlinear well equations have been fully integrated into the Jacobian matrix for the reservoir conservation equations, minimizing the matrix bandwidth.

  18. Finite element modeling of a 3D coupled foot-boot model.

    PubMed

    Qiu, Tian-Xia; Teo, Ee-Chon; Yan, Ya-Bo; Lei, Wei

    2011-12-01

    Increasingly, musculoskeletal models of the human body are used as powerful tools to study biological structures. The lower limb, and in particular the foot, is of interest because it is the primary physical interaction between the body and the environment during locomotion. The goal of this paper is to adopt the finite element (FE) modeling and analysis approaches to create a state-of-the-art 3D coupled foot-boot model for future studies on biomechanical investigation of stress injury mechanism, foot wear design and parachute landing fall simulation. In the modeling process, the foot-ankle model with lower leg was developed based on Computed Tomography (CT) images using ScanIP, Surfacer and ANSYS. Then, the boot was represented by assembling the FE models of upper, insole, midsole and outsole built based on the FE model of the foot-ankle, and finally the coupled foot-boot model was generated by putting together the models of the lower limb and boot. In this study, the FE model of foot and ankle was validated during balance standing. There was a good agreement in the overall patterns of predicted and measured plantar pressure distribution published in literature. The coupled foot-boot model will be fully validated in the subsequent works under both static and dynamic loading conditions for further studies on injuries investigation in military and sports, foot wear design and characteristics of parachute landing impact in military. PMID:21676642

  19. High-resolution coupled ice sheet-ocean modeling using the POPSICLES model

    NASA Astrophysics Data System (ADS)

    Ng, E. G.; Martin, D. F.; Asay-Davis, X.; Price, S. F.; Collins, W.

    2014-12-01

    It is expected that a primary driver of future change of the Antarctic ice sheet will be changes in submarine melting driven by incursions of warm ocean water into sub-ice shelf cavities. Correctly modeling this response on a continental scale will require high-resolution modeling of the coupled ice-ocean system. We describe the computational and modeling challenges in our simulations of the full Southern Ocean coupled to a continental-scale Antarctic ice sheet model at unprecedented spatial resolutions (0.1 degree for the ocean model and adaptive mesh refinement down to 500m in the ice sheet model). The POPSICLES model couples the POP2x ocean model, a modified version of the Parallel Ocean Program (Smith and Gent, 2002), with the BISICLES ice-sheet model (Cornford et al., 2012) using a synchronous offline-coupling scheme. Part of the PISCEES SciDAC project and built on the Chombo framework, BISICLES makes use of adaptive mesh refinement to fully resolve dynamically-important regions like grounding lines and employs a momentum balance similar to the vertically-integrated formulation of Schoof and Hindmarsh (2009). Results of BISICLES simulations have compared favorably to comparable simulations with a Stokes momentum balance in both idealized tests like MISMIP3D (Pattyn et al., 2013) and realistic configurations (Favier et al. 2014). POP2x includes sub-ice-shelf circulation using partial top cells (Losch, 2008) and boundary layer physics following Holland and Jenkins (1999), Jenkins (2001), and Jenkins et al. (2010). Standalone POP2x output compares well with standard ice-ocean test cases (e.g., ISOMIP; Losch, 2008) and other continental-scale simulations and melt-rate observations (Kimura et al., 2013; Rignot et al., 2013). For the POPSICLES Antarctic-Southern Ocean simulations, ice sheet and ocean models communicate at one-month coupling intervals.

  20. Modeling solute advection coupled with sorption kinetics in heterogeneous formations

    NASA Astrophysics Data System (ADS)

    Selroos, Jan-Olof; Cvetkovic, Vladimir

    1992-05-01

    A method for coupling sorption kinetics and solute advection in particle-tracking models is proposed; this method is efficient for the case where sorption rate coefficients can be assumed constant field scale parameters. A simulation example of reactive solute advection in two-dimensional heterogeneous porous media is presented. The effect of sorption kinetics on solute advection is investigated. Nonequilibrium effects are exhibited as enhanced tailing in the solute breakthrough. Because high variability in the hydraulic conductivity also yields enhanced tailing, the nonequilibrium effect is more pronounced for the case of low variability. Moreover, it may be difficult to distinguish cases of low variability with nonequilibrium sorption from cases of high variability with equilibrium sorption. A comparison of Monte Carlo ensemble results is made with an analytical model for the mass arrival of kinetically sorbing solute in heterogeneous porous media obtained using first-order perturbation. The comparison indicates that the analytical model provides reasonable approximations of the expected solute breakthrough if the variance of the natural logarithm of the hydraulic conductivity is smaller than 1.

  1. A Generalized Hydrodynamics Model for Strongly Coupled Plasmas

    NASA Astrophysics Data System (ADS)

    Diaw, Abdourahmane; Murillo, Michael Sean

    2015-11-01

    Starting with the equations of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, we obtain the density, momentum and stress tensor-moment equations. The closure proceeds in two steps. The first that guarantees an equilibrium state is given by density functional theory. It ensures self consistency in the equation-of-state properties of the plasma. The second involves modifying the two-body distribution function to include collisions in the relaxation of the stress tensor. The resulting generalized hydrodynamics thus includes all impacts of Coulomb coupling, viscous damping, and the high-frequency response. We compare our results with those of several known models, including generalized hydrodynamic theory and models obtained using the Singwi-Tosi-Land-Sjolander approximation and the quasi-localized charge approximation. We find that the viscoelastic response, including both the high-frequency elastic generalization and viscous wave damping, is important for correctly describing ion-acoustic waves. We illustrate this result by considering three very different systems: ultracold plasmas, dusty plasmas, and dense plasmas. The new model is validated by comparing its results with those obtained from molecular-dynamics simulations of Yukawa plasmas, and the agreement is excellent. This work was supported by the Air Force Office of Scientific Research (Grant No. FA9550-12-1-0344).

  2. Coupled transport/hyperelastic model for nastic materials

    NASA Astrophysics Data System (ADS)

    Homison, Chris; Weiland, Lisa M.

    2006-03-01

    Nastic materials are high energy density active materials that mimic processes used in the plant kingdom to produce large deformations through the conversion of chemical energy. These materials utilize the controlled transport of charge and fluid across a selectively-permeable membrane to achieve bulk deformation in a process referred to in the plant kingdom as nastic movements. The nastic material being developed consists of synthetic membranes containing biological ion pumps, ion channels, and ion exchangers surrounding fluid-filled cavities embedded within a polymer matrix. In this paper the formulation of a biological transport model and its coupling with a hyperelastic finite element model of the polymer matrix is discussed. The transport model includes contributions from ion pumps, ion exchangers, and solvent flux. This work will form the basis for a feedback loop in material synthesis efforts. The goal of these studies is to determine the relative importance of the various parameters associated with both the polymer matrix and the biological transport components.

  3. A simple coupled model of tropical Atlantic decadal climate variability

    NASA Astrophysics Data System (ADS)

    Kushnir, Yochanan; Seager, Richard; Miller, Jennifer; Chiang, John C. H.

    2002-12-01

    A linear, zonally averaged model of the interaction between the tropical Atlantic (TA) atmosphere and ocean is presented. A balance between evaporation and meridional heat advection in the mixed layer determines the sea surface temperature tendency. The atmosphere is a fixed-depth, sub-cloud layer in which the specific humidity anomaly is determined by a steady-state balance between evaporation, meridional advection, and a parameterized humidity exchange with the free atmosphere. When the model is integrated, forced with observed surface wind anomalies from 1965 to the present, its simulation of the observed sea surface temperature (SST) is realistic and comparable to a simulation with a full ocean GCM. A statistical representation of surface winds and their relationship to the SST gradient across the equator is used to formulate and test a coupled model of their regional variability. Forced on both sides of the equator, in the trade-wind regions, with ``white-noise'' windspeed perturbations, the SST-wind relationship in the near-equatorial region feeds back positively on existing SST anomalies and gives rise to decadal variability.

  4. Modeling of magnetoelastic nanostructures with a fully coupled mechanical-micromagnetic model.

    PubMed

    Liang, Cheng-Yen; Keller, Scott M; Sepulveda, Abdon E; Bur, Alexandre; Sun, Wei-Yang; Wetzlar, Kyle; Carman, Gregory P

    2014-10-31

    Micromagnetic simulations of magnetoelastic nanostructures traditionally rely on either the Stoner-Wohlfarth model or the Landau-Lifshitz-Gilbert (LLG) model, assuming uniform strain (and/or assuming uniform magnetization). While the uniform strain assumption is reasonable when modeling magnetoelastic thin films, this constant strain approach becomes increasingly inaccurate for smaller in-plane nanoscale structures. This paper presents analytical work intended to significantly improve the simulation of finite structures by fully coupling the LLG model with elastodynamics, i.e., the partial differential equations are intrinsically coupled. The coupled equations developed in this manuscript, along with the Stoner-Wohlfarth model and the LLG (constant strain) model are compared to experimental data on nickel nanostructures. The nickel nanostructures are 100 × 300 × 35 nm single domain elements that are fabricated on a Si/SiO2 substrate; these nanostructures are mechanically strained when they experience an applied magnetic field, which is used to generate M vs H curves. Results reveal that this paper's fully-coupled approach corresponds the best with the experimental data on coercive field changes. This more sophisticated modeling technique is critical for guiding the design process of future nanoscale strain-mediated multiferroic elements, such as those needed in memory systems. PMID:25288449

  5. Modeling of magnetoelastic nanostructures with a fully coupled mechanical-micromagnetic model

    NASA Astrophysics Data System (ADS)

    Liang, Cheng-Yen; Keller, Scott M.; Sepulveda, Abdon E.; Bur, Alexandre; Sun, Wei-Yang; Wetzlar, Kyle; Carman, Gregory P.

    2014-10-01

    Micromagnetic simulations of magnetoelastic nanostructures traditionally rely on either the Stoner-Wohlfarth model or the Landau-Lifshitz-Gilbert (LLG) model, assuming uniform strain (and/or assuming uniform magnetization). While the uniform strain assumption is reasonable when modeling magnetoelastic thin films, this constant strain approach becomes increasingly inaccurate for smaller in-plane nanoscale structures. This paper presents analytical work intended to significantly improve the simulation of finite structures by fully coupling the LLG model with elastodynamics, i.e., the partial differential equations are intrinsically coupled. The coupled equations developed in this manuscript, along with the Stoner-Wohlfarth model and the LLG (constant strain) model are compared to experimental data on nickel nanostructures. The nickel nanostructures are 100 × 300 × 35 nm single domain elements that are fabricated on a Si/SiO2 substrate; these nanostructures are mechanically strained when they experience an applied magnetic field, which is used to generate M vs H curves. Results reveal that this paper’s fully-coupled approach corresponds the best with the experimental data on coercive field changes. This more sophisticated modeling technique is critical for guiding the design process of future nanoscale strain-mediated multiferroic elements, such as those needed in memory systems.

  6. 5-Step Methodology for Evaluation and Adaptation of Print Patient Health Information to Meet the <5th Grade Readability Criterion

    PubMed Central

    Hill-Briggs, Felicia; Schumann, Kristina P.; Dike, Ogechi

    2012-01-01

    Background In the setting of declining U.S. literacy, new policies include use of clear communication and low literacy accessibility practices with all patients. Reliable methods for adapting health information to meet such criteria remain a pressing need. Objectives To report method validation (Study 1) and method replication (Study 2) procedures and outcomes for a 5-step method for evaluating and adapting print health information to meet the current low literacy criterion of <5th grade readability. Materials Sets of 18 and 11 publicly-disseminated patient education documents developed by a university-affiliated medical center. Measures Three low-literacy criteria were strategically targeted for efficient, systematic evaluation and text modification to meet a <5th grade reading level: sentence length <15 words, writing in active voice, and use of common words with multisyllabic words (>2–3 syllables) minimized or avoided. Inter-rater reliability for the document evaluations was determined. Results Training in the methodology resulted in inter-rater reliability of 0.99–1.00 in Study 1 and 0.98–1.00 in Study 2. Original documents met none of the targeted low literacy criteria. In Study 1, following low-literacy adaptation, mean reading grade level decreased from 10.4±1.8 to 3.8±0.6 (p<0.0001), with consistent achievement of criteria for words per sentence, passive voice, and syllables per word. Study 2 demonstrated similar achievement of all target criteria, with a resulting decrease in mean reading grade level from 11.0±1.8 to 4.6±0.3 (p < 0.0001). Conclusions The 5-step methodology proved teachable and efficient. Targeting a limited set of modifiable criteria was effective and reliable in achieving <5th grade readability. PMID:22354210

  7. Coupling Radar Rainfall to Hydrological Models for Water Abstraction Management

    NASA Astrophysics Data System (ADS)

    Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; MacDonald, Ken

    2015-04-01

    The impacts of climate change and growing water use are likely to put considerable pressure on water resources and the environment. In the UK, a reform to surface water abstraction policy has recently been proposed which aims to increase the efficiency of using available water resources whilst minimising impacts on the aquatic environment. Key aspects to this reform include the consideration of dynamic rather than static abstraction licensing as well as introducing water trading concepts. Dynamic licensing will permit varying levels of abstraction dependent on environmental conditions (i.e. river flow and quality). The practical implementation of an effective dynamic abstraction strategy requires suitable flow forecasting techniques to inform abstraction asset management. Potentially the predicted availability of water resources within a catchment can be coupled to predicted demand and current storage to inform a cost effective water resource management strategy which minimises environmental impacts. The aim of this work is to use a historical analysis of UK case study catchment to compare potential water resource availability using modelled dynamic abstraction scenario informed by a flow forecasting model, against observed abstraction under a conventional abstraction regime. The work also demonstrates the impacts of modelling uncertainties on the accuracy of predicted water availability over range of forecast lead times. The study utilised a conceptual rainfall-runoff model PDM - Probability-Distributed Model developed by Centre for Ecology & Hydrology - set up in the Dove River catchment (UK) using 1km2 resolution radar rainfall as inputs and 15 min resolution gauged flow data for calibration and validation. Data assimilation procedures are implemented to improve flow predictions using observed flow data. Uncertainties in the radar rainfall data used in the model are quantified using artificial statistical error model described by Gaussian distribution and

  8. A report on 5th congress of Asia Pacific Pediatric Cardiac Society, New Delhi, India, 6-9 March 2014

    PubMed Central

    Gupta, Saurabh K; Saxena, Anita

    2015-01-01

    The 5th Congress of Asia Pacific Pediatric Cardiac Society was held in New Delhi from 6-9 March 2014. This article describes the journey of preparing and hosting one of the largest international events in the specialty of Pediatric Cardiac Care ever held in India. A total of 938 delegates, including 400 from outside India, participated. The scientific program was inclusive keeping in mind the diverse background of delegates from the member nations. Large numbers of research papers were presented, mostly by fellows in training. PMID:25684899

  9. IBA investigations of loose garnets from Pietroasa, Apahida and Cluj-Someşeni treasures (5th century AD)

    NASA Astrophysics Data System (ADS)

    Bugoi, R.; Oanţă-Marghitu, R.; Calligaro, T.

    2016-03-01

    This paper reports the archaeometric investigations of 418 loose garnets from Pietroasa and Cluj-Someşeni treasures and Apahida II and III princely grave inventories (5th century AD). The chemical composition of the gems was determined by external beam micro-PIXE technique at the AGLAE accelerator of C2RMF, Paris, France. Complementary observations made by Optical Microscopy revealed details on the gemstones cutting and polishing and permitted to identify certain mineral inclusions. The compositional results evidenced several types of garnets from the pyralspite series, suggesting distinct provenances for these Early Medieval gems.

  10. Coupling a geodynamic seismic cycling model to rupture dynamic simulations

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; van Dinther, Ylona

    2014-05-01

    The relevance and results of dynamic rupture scenarios are implicitly linked to the geometry and pre-existing stress and strength state on a fault. The absolute stresses stored along faults during interseismic periods, are largely unquantifiable. They are, however, pivotal in defining coseismic rupture styles, near-field ground motion, and macroscopic source properties (Gabriel et al., 2012). Obtaining these in a physically consistent manner requires seismic cycling models, which directly couple long-term deformation processes (over 1000 year periods), the self-consistent development of faults, and the resulting dynamic ruptures. One promising approach to study seismic cycling enables both the generation of spontaneous fault geometries and the development of thermo-mechanically consistent fault stresses. This seismo-thermo-mechanical model has been developed using a methodology similar to that employed to study long-term lithospheric deformation (van Dinther et al., 2013a,b, using I2ELVIS of Gerya and Yuen, 2007). We will innovatively include the absolute stress and strength values along physically consistent evolving non-finite fault zones (regions of strain accumulation) from the geodynamic model into dynamic rupture simulations as an initial condition. The dynamic rupture simulations will be performed using SeisSol, an arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) scheme (Pelties et al., 2012). The dynamic rupture models are able to incorporate the large degree of fault geometry complexity arising in naturally evolving geodynamic models. We focus on subduction zone settings with and without a splay fault. Due to the novelty of the coupling, we first focus on methodological challenges, e.g. the synchronization of both methods regarding the nucleation of events, the localization of fault planes, and the incorporation of similar frictional constitutive relations. We then study the importance of physically consistent fault stress, strength, and

  11. Understanding subtropical anvil cirrus: A coupled modeling study

    NASA Astrophysics Data System (ADS)

    Carver, Robert Wyatt

    This research investigates the sensitivity of anvil layer cirrus's characteristics to its mesoscale environment. A coupled modeling system composed of a mesoscale model and cloud model is used to represent the evolution of systems with different scales. Lagrangian trajectories in the mesoscale model are used to determine the mesoscale environment of the simulated anvil and calculate the mesoscale forcing. A new sedimentation parameterization for the cloud model is developed to better represent fall speeds for large particles. Convection and the resulting outflow cirrus occurring near Ft. Myers, Florida on July 16, 2002 are used for the case study. The mesoscale model produced convection and an ice cloud similar to what was observed that day. The cloud model was used to determine the set of cloud processes in response to the mesoscale forcing that produced more condensate and prolonged cloud lifetime. These simulations show that differential radiative heating and cooling is the key process. The cooling and moistening in response to the mesoscale forcing produces more ice, enhancing cloud-top radiative cooling and cloud-base infrared warming. This generates more buoyancy, strengthening the cloud's updrafts and producing many small crystals to further enhance the cloud-top cooling, until sedimentation removes enough mass to end the positive feedbacks. The presence and magnitude of the mesoscale forcing alters the amount of condensate formed, altering the cloud-top cooling rate and the cloud's response to the forcing. The anvil cloud simulation was relatively insensitive to the initial condensate once the cloud becomes optically thick enough to be considered a black-body. While longwave cloud-top cooling is necessary for the interactions between mesoscale forcing and cloud dynamics, the most turbulent anvil cirrus layers require shortwave in-cloud warming. In response to recent measurements of the deposition coefficient, alpha d, I develop a parameterization that

  12. Model reduction of a coupled numerical model using proper orthogonal decomposition

    NASA Astrophysics Data System (ADS)

    Li, Xinya; Chen, Xiao; Hu, Bill X.; Navon, I. Michael

    2013-12-01

    POD is applied to the coupled variable-density flow and solute transport system.Detailed derivation is presented for the developed GFEM-POD reduced-order model.Henry problem and Elder problem are tested to confirm the proposed procedure.Accuracy is mainly influenced by the optimal selection and update of snapshots.Reduced model can substitute full model with much less computational cost.

  13. Standard Model Gauge Couplings from Gauge-Dilatation Symmetry Breaking

    NASA Astrophysics Data System (ADS)

    Odagiri, Kosuke

    2014-09-01

    It is well known that the self-energy of the gauge bosons is quadratically divergent in the Standard Model when a simple cutoff is imposed. We demonstrate phenomenologically that the quadratic divergences in fact unify. The unification occurs at a surprisingly low scale, GeV. Suppose now that there is a spontaneously broken rotational symmetry between the space-time coordinates and gauge theoretical phases. The symmetry-breaking pattern is such that the gauge bosons arise as the massless Goldstone bosons, whereas the dilatonic mode acts as the massive (Higgs) boson, whose vacuum expectation value determines the gauge couplings. In this case, the quadratic divergences or the tadpoles of the gauge boson self-energy should indeed unify because these divergences need to be cancelled by a universal dilatonic contribution, assuming dynamical symmetry breaking. If there is dynamical symmetry breaking, we are in principle able to calculate the value of the gauge couplings as well as the scale hierarchy . We perform this calculation by adopting a naive quartic symmetry-breaking potential which unfortunately violates local gauge invariance. Using tadpole-cancellation and dilatonic self-energy conditions, the value of is then found to be approximately GeV in the Feynman gauge and GeV in the Landau gauge. The cancellation of an anomaly in the dilaton self-energy requires that the number of fermionic generations equals three. The symmetry-breaking needs to be driven by some other mass-generating mechanism such as electroweak symmetry breaking. Our estimation for is of the correct order if GeV.

  14. A Coupled THMC model of FEBEX mock-up test

    SciTech Connect

    Zheng, Liange; Samper, Javier

    2008-09-15

    FEBEX (Full-scale Engineered Barrier EXperiment) is a demonstration and research project for the engineered barrier system (EBS) of a radioactive waste repository in granite. It includes two full-scale heating and hydration tests: the in situ test performed at Grimsel (Switzerland) and a mock-up test operating at CIEMAT facilities in Madrid (Spain). The mock-up test provides valuable insight on thermal, hydrodynamic, mechanical and chemical (THMC) behavior of EBS because its hydration is controlled better than that of in situ test in which the buffer is saturated with water from the surrounding granitic rock. Here we present a coupled THMC model of the mock-up test which accounts for thermal and chemical osmosis and bentonite swelling with a state-surface approach. The THMC model reproduces measured temperature and cumulative water inflow data. It fits also relative humidity data at the outer part of the buffer, but underestimates relative humidities near the heater. Dilution due to hydration and evaporation near the heater are the main processes controlling the concentration of conservative species while surface complexation, mineral dissolution/precipitation and cation exchanges affect significantly reactive species as well. Results of sensitivity analyses to chemical processes show that pH is mostly controlled by surface complexation while dissolved cations concentrations are controlled by cation exchange reactions.

  15. A coupled geomorphic and ecological model of tidal marsh evolution.

    PubMed

    Kirwan, Matthew L; Murray, A Brad

    2007-04-10

    The evolution of tidal marsh platforms and interwoven channel networks cannot be addressed without treating the two-way interactions that link biological and physical processes. We have developed a 3D model of tidal marsh accretion and channel network development that couples physical sediment transport processes with vegetation biomass productivity. Tidal flow tends to cause erosion, whereas vegetation biomass, a function of bed surface depth below high tide, influences the rate of sediment deposition and slope-driven transport processes such as creek bank slumping. With a steady, moderate rise in sea level, the model builds a marsh platform and channel network with accretion rates everywhere equal to the rate of sea-level rise, meaning water depths and biological productivity remain temporally constant. An increase in the rate of sea-level rise, or a reduction in sediment supply, causes marsh-surface depths, biomass productivity, and deposition rates to increase while simultaneously causing the channel network to expand. Vegetation on the marsh platform can promote a metastable equilibrium where the platform maintains elevation relative to a rapidly rising sea level, although disturbance to vegetation could cause irreversible loss of marsh habitat. PMID:17389384

  16. Finite Nuclei in the Quark-Meson Coupling Model

    NASA Astrophysics Data System (ADS)

    Stone, J. R.; Guichon, P. A. M.; Reinhard, P. G.; Thomas, A. W.

    2016-03-01

    We report the first use of the effective quark-meson coupling (QMC) energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the nonrelativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having a clear physics basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist, however, multiple Skyrme parameter sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter.

  17. Coupled Growth and Division of Model Protocell Membranes

    PubMed Central

    2009-01-01

    The generation of synthetic forms of cellular life requires solutions to the problem of how biological processes such as cyclic growth and division could emerge from purely physical and chemical systems. Small unilamellar fatty acid vesicles grow when fed with fatty acid micelles and can be forced to divide by extrusion, but this artificial division process results in significant loss of protocell contents during each division cycle. Here we describe a simple and efficient pathway for model protocell membrane growth and division. The growth of large multilamellar fatty acid vesicles fed with fatty acid micelles, in a solution where solute permeation across the membranes is slow, results in the transformation of initially spherical vesicles into long thread-like vesicles, a process driven by the transient imbalance between surface area and volume growth. Modest shear forces are then sufficient to cause the thread-like vesicles to divide into multiple daughter vesicles without loss of internal contents. In an environment of gentle shear, protocell growth and division are thus coupled processes. We show that model protocells can proceed through multiple cycles of reproduction. Encapsulated RNA molecules, representing a primitive genome, are distributed to the daughter vesicles. Our observations bring us closer to the laboratory synthesis of a complete protocell consisting of a self-replicating genome and a self-replicating membrane compartment. In addition, the robustness and simplicity of this pathway suggests that similar processes might have occurred under the prebiotic conditions of the early Earth. PMID:19323552

  18. Finite Nuclei in the Quark-Meson Coupling Model.

    PubMed

    Stone, J R; Guichon, P A M; Reinhard, P G; Thomas, A W

    2016-03-01

    We report the first use of the effective quark-meson coupling (QMC) energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the nonrelativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having a clear physics basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist, however, multiple Skyrme parameter sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter. PMID:26991171

  19. Conference on Satellite Meteorology and Oceanography, 5th, London, England, Sept. 3-7, 1990, Preprints

    SciTech Connect

    Not Available

    1990-01-01

    The present conference on satellite meteorology and oceanography discusses climate and clouds, retrieval algorithms, air-sea phenomenology, oceanographic applications, SSM/I, mesoscale, synoptic, and NWP applications, and future satellites and systems. Attention is given to the properties of cirrus clouds measured by satellites and lidars, the geographical variation of the diurnal cycle of clouds from ISCCP, the susceptibility of cloud reflectance to pollution, and a global analysis of aerosol-cloud interactions. Topics addressed include precision intercomparisons between MSU channel 2 and radiosonde data over the U.S., humidity estimates from Meteosat observations, the assimilation of altimeter observations into a global wave model, and atmospheric stratification effects on scatterometer model functions. Also discussed are observations of Indian Ocean eddy variability, the deconvolution of GOES infrared data, short-range variations in total cloud cover in the tropics, and rainfall monitoring by the SSM/I in middle latitudes.

  20. Global coupled ocean-atmosphere general circulation models in LASG/IAP

    NASA Astrophysics Data System (ADS)

    Yongqiang, Yu; Xuehong, Zhang; Yufu, Guo

    2004-06-01

    Coupled ocean-atmospheric general circulation models are the only tools to quantitatively simulate the climate system. Since the end of the 1980s, a group of scientists in the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), have been working to develop a global OGCM and a global coupled ocean-atmosphere general circulation model (CGCM). From the original flux anomaly-coupling model developed in the beginning of the 1990s to the latest directly-coupling model, LASG scientists have developed four global coupled GCMs. This study summarizes the development history of these models and describes the third and fourth coupled GCMs and selected applications. Strengths and weaknesses of these models are highlighted.

  1. From strong to weak coupling in holographic models of thermalization

    NASA Astrophysics Data System (ADS)

    Grozdanov, Sašo; Kaplis, Nikolaos; Starinets, Andrei O.

    2016-07-01

    We investigate the analytic structure of thermal energy-momentum tensor correlators at large but finite coupling in quantum field theories with gravity duals. We compute corrections to the quasinormal spectra of black branes due to the presence of higher derivative R 2 and R 4 terms in the action, focusing on the dual to N=4 SYM theory and Gauss-Bonnet gravity. We observe the appearance of new poles in the complex frequency plane at finite coupling. The new poles interfere with hydrodynamic poles of the correlators leading to the breakdown of hydrodynamic description at a coupling-dependent critical value of the wave-vector. The dependence of the critical wave vector on the coupling implies that the range of validity of the hydrodynamic description increases monotonically with the coupling. The behavior of the quasinormal spectrum at large but finite coupling may be contrasted with the known properties of the hierarchy of relaxation times determined by the spectrum of a linearized kinetic operator at weak coupling. We find that the ratio of a transport coefficient such as viscosity to the relaxation time determined by the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the vicinity of infinite coupling but flattens out for weaker coupling, suggesting an extrapolation from strong coupling to the kinetic theory result. We note that the behavior of the quasinormal spectrum is qualitatively different depending on whether the ratio of shear viscosity to entropy density is greater or less than the universal, infinite coupling value of ℏ /4π k B . In the former case, the density of poles increases, indicating a formation of branch cuts in the weak coupling limit, and the spectral function shows the appearance of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to conjectured bounds on relaxation time in quantum systems.

  2. Coupled Deterministic-Monte Carlo Transport for Radiation Portal Modeling

    SciTech Connect

    Smith, Leon E.; Miller, Erin A.; Wittman, Richard S.; Shaver, Mark W.

    2008-01-14

    Radiation portal monitors are being deployed, both domestically and internationally, to detect illicit movement of radiological materials concealed in cargo. Evaluation of the current and next generations of these radiation portal monitor (RPM) technologies is an ongoing process. 'Injection studies' that superimpose, computationally, the signature from threat materials onto empirical vehicle profiles collected at ports of entry, are often a component of the RPM evaluation process. However, measurement of realistic threat devices can be both expensive and time-consuming. Radiation transport methods that can predict the response of radiation detection sensors with high fidelity, and do so rapidly enough to allow the modeling of many different threat-source configurations, are a cornerstone of reliable evaluation results. Monte Carlo methods have been the primary tool of the detection community for these kinds of calculations, in no small part because they are particularly effective for calculating pulse-height spectra in gamma-ray spectrometers. However, computational times for problems with a high degree of scattering and absorption can be extremely long. Deterministic codes that discretize the transport in space, angle, and energy offer potential advantages in computational efficiency for these same kinds of problems, but the pulse-height calculations needed to predict gamma-ray spectrometer response are not readily accessible. These complementary strengths for radiation detection scenarios suggest that coupling Monte Carlo and deterministic methods could be beneficial in terms of computational efficiency. Pacific Northwest National Laboratory and its collaborators are developing a RAdiation Detection Scenario Analysis Toolbox (RADSAT) founded on this coupling approach. The deterministic core of RADSAT is Attila, a three-dimensional, tetrahedral-mesh code originally developed by Los Alamos National Laboratory, and since expanded and refined by Transpire, Inc. [1

  3. Offshore observations of aftershocks following the January 5th 2013 Mw 7.5 Queen Charlotte-Fairweather fault earthquake, southeast Alaska

    NASA Astrophysics Data System (ADS)

    Roland, E. C.; Gulick, S. P.; Levoir, M. A.; Haeussler, P. J.

    2013-12-01

    We present initial results from a rapid-response ocean bottom seismometer (OBS) deployment that recorded aftershock activity on the Queen Charlotte-Fairweather (QC-F) fault following the Mw 7.5 earthquake on January 5th 2013 near Craig, Alaska. This earthquake was the second of two Mw > 7 events on this fault system in a 3 month time period; the Craig earthquake followed a Mw 7.8 thrust event that occurred in October 2012, west of Haida Gwaii, British Columbia. Although the QC-F is a major plate boundary fault, little is known about the regional fault structure, interseismic coupling, and rheological controls on the depth distribution of seismic slip along the continent-ocean transform. The majority of the QC-F fault system extends offshore western British Columbia and southeast Alaska, making it difficult to characterize earthquakes and fault deformation with land-based seismic and geodetic instruments. This experiment is the first ever offshore seismometer deployment to record earthquake activity along this northern segment of the QC-F system, and was set in motion with help from the US Coast Guard, who provided a vessel and crew to deploy and recover the OBS array on short notice. The seismic array utilized 6 GeoPro short period OBS from the University of Texas Institute for Geophysics, which recorded approximately 3 weeks of aftershock activity in April-May of 2013. Combining high-quality local OBS recordings with land-based seismic observations from Alaska Earthquake Information Center (AEIC) stations to the east, we present more precise aftershock locations and depths that help to better characterize fault zone architecture along the northern section of the QC-F. Although moment tensor solutions indicate that the January 5th mainshock sustained slip consistent with Pacific-North America plate motions, aftershock focal mechanisms indicate some interaction with neighboring faults, such as the Chatham Straight fault. This new OBS dataset will also help to

  4. Coupling hydrodynamic and wave propagation modeling for waveform modeling of SPE.

    NASA Astrophysics Data System (ADS)

    Larmat, C. S.; Steedman, D. W.; Rougier, E.; Delorey, A.; Bradley, C. R.

    2015-12-01

    The goal of the Source Physics Experiment (SPE) is to bring empirical and theoretical advances to the problem of detection and identification of underground nuclear explosions. This paper presents effort to improve knowledge of the processes that affect seismic wave propagation from the hydrodynamic/plastic source region to the elastic/anelastic far field thanks to numerical modeling. The challenge is to couple the prompt processes that take place in the near source region to the ones taking place later in time due to wave propagation in complex 3D geologic environments. In this paper, we report on results of first-principles simulations coupling hydrodynamic simulation codes (Abaqus and CASH), with a 3D full waveform propagation code, SPECFEM3D. Abaqus and CASH model the shocked, hydrodynamic region via equations of state for the explosive, borehole stemming and jointed/weathered granite. LANL has been recently employing a Coupled Euler-Lagrange (CEL) modeling capability. This has allowed the testing of a new phenomenological model for modeling stored shear energy in jointed material. This unique modeling capability has enabled highfidelity modeling of the explosive, the weak grout-filled borehole, as well as the surrounding jointed rock. SPECFEM3D is based on the Spectral Element Method, a direct numerical method for full waveform modeling with mathematical accuracy (e.g. Komatitsch, 1998, 2002) thanks to its use of the weak formulation of the wave equation and of high-order polynomial functions. The coupling interface is a series of grid points of the SEM mesh situated at the edge of the hydrodynamic code domain. Displacement time series at these points are computed from output of CASH or Abaqus (by interpolation if needed) and fed into the time marching scheme of SPECFEM3D. We will present validation tests and waveforms modeled for several SPE tests conducted so far, with a special focus on effect of the local topography.

  5. Modeling Nitrogen Leaching With A Biogeochemical Model Coupled With Soil Hydrology Model

    NASA Astrophysics Data System (ADS)

    Barman, R.; Yang, X.; Jain, A.; Post, W. M.; Sivapalan, M.

    2008-12-01

    Land use changes for cropland, excessive application of fertilizers in agriculture, and increase in anthropogenic activities such as fossil fuel burning have lead to widespread increases in anthropogenic production of reactive N and NH3 emissions, and N deposition rates. An important consequence of these processes is intensification of soil nutrient leaching activities, leading to serious ground water contamination problems. The current study focuses on the issue of nitrogen (nitrate and ammonium) leaching due to land cover changes for cropland, excess N fertilizer application, and atmospheric nitrogen deposition on nitrogen leaching at a global scale. Simulations of nitrogen leaching require integration of processes involving soil hydrology and biogeochemical cycles. An existing terrestrial coupled carbon-nitrogen cycle model, Integrated Science Assessment Model (ISAM), was used to estimate nitrogen leaching. The N-cycle in ISAM includes the major processes associated with nitrogen (immobilization, mineralization, nitrification, denitrification, leaching, nitrogen fixation, and vegetation nitrogen uptake). ISAM also considers how carbon and nitrogen dynamics are influenced by the effects of human perturbations to the N cycle including atmospheric deposition and fertilizer application, and the fate of N in land use activities, i.e., deforestation and agricultural harvest. In this study, the ISAM soil hydrology was extended and improved with CLM 3.5 hydrology processes and algorithms, which extended the modeling capabilities to consider the prediction of nitrogen leaching. The model performance was evaluated with flow and nutrient data at several locations within the Upper Sangamon River Basin in Illinois, and flow data in contrasting watersheds in Oklahoma. This talk will focus on describing the results of a series of modeling experiments examining the influence of land management changes for cropland and nitrogen deposition on nitrogen leaching at a global scale

  6. A coupled DEM-CFD method for impulse wave modelling

    NASA Astrophysics Data System (ADS)

    Zhao, Tao; Utili, Stefano; Crosta, GiovanBattista

    2015-04-01

    Rockslides can be characterized by a rapid evolution, up to a possible transition into a rock avalanche, which can be associated with an almost instantaneous collapse and spreading. Different examples are available in the literature, but the Vajont rockslide is quite unique for its morphological and geological characteristics, as well as for the type of evolution and the availability of long term monitoring data. This study advocates the use of a DEM-CFD framework for the modelling of the generation of hydrodynamic waves due to the impact of a rapid moving rockslide or rock-debris avalanche. 3D DEM analyses in plane strain by a coupled DEM-CFD code were performed to simulate the rockslide from its onset to the impact with still water and the subsequent wave generation (Zhao et al., 2014). The physical response predicted is in broad agreement with the available observations. The numerical results are compared to those published in the literature and especially to Crosta et al. (2014). According to our results, the maximum computed run up amounts to ca. 120 m and 170 m for the eastern and western lobe cross sections, respectively. These values are reasonably similar to those recorded during the event (i.e. ca. 130 m and 190 m respectively). In these simulations, the slope mass is considered permeable, such that the toe region of the slope can move submerged in the reservoir and the impulse water wave can also flow back into the slope mass. However, the upscaling of the grains size in the DEM model leads to an unrealistically high hydraulic conductivity of the model, such that only a small amount of water is splashed onto the northern bank of the Vajont valley. The use of high fluid viscosity and coarse grain model has shown the possibility to model more realistically both the slope and wave motions. However, more detailed slope and fluid properties, and the need for computational efficiency should be considered in future research work. This aspect has also been

  7. 2 π production in the Giessen coupled-channels model

    NASA Astrophysics Data System (ADS)

    Shklyar, V.; Lenske, H.; Mosel, U.

    2016-04-01

    The coupled-channels Lagrangian approach underlying the Giessen model (GiM) is extended to describe the π N →π N ,2 π N scattering in the resonance energy region. As a feasibility study we investigate single- and double-pion production up to the second resonance region. The 2 π N production has been significantly improved by using the isobar approximation with σ N and π Δ (1232 ) in the intermediate state. The three-body unitarity is maintained up to an interference pattern between the isobar subchannels. The scattering amplitudes are obtained as a solution of the Bethe-Salpeter equation in the K -matrix approximation. As a first application we perform a partial-wave analysis of the π N →π N ,π0π0N reactions in the Roper resonance region. We obtain Rσ N(1440 ) =27-9+4% and Rπ Δ(1440 ) =12-3+5% for the σ N and π Δ (1232 ) decay branching ratios of N*(1440 ) , respectively. The extracted π N inelasticities and reaction amplitudes are consistent with the results from other groups.

  8. Physical Modeling of Dynamic Coupling between Chromosomal Loci.

    PubMed

    Lampo, Thomas J; Kennard, Andrew S; Spakowitz, Andrew J

    2016-01-19

    The motion of chromosomal DNA is essential to many biological processes, including segregation, transcriptional regulation, recombination, and packaging. Physical understanding of these processes would be dramatically enhanced through predictive, quantitative modeling of chromosome dynamics of multiple loci. Using a polymer dynamics framework, we develop a prediction for the correlation in the velocities of two loci on a single chromosome or otherwise connected by chromatin. These predictions reveal that the signature of correlated motion between two loci can be identified by varying the lag time between locus position measurements. In general, this theory predicts that as the lag time interval increases, the dual-loci dynamic behavior transitions from being completely uncorrelated to behaving as an effective single locus. This transition corresponds to the timescale of the stress communication between loci through the intervening segment. This relatively simple framework makes quantitative predictions based on a single timescale fit parameter that can be directly compared to the in vivo motion of fluorescently labeled chromosome loci. Furthermore, this theoretical framework enables the detection of dynamically coupled chromosome regions from the signature of their correlated motion. PMID:26789757

  9. Symposium on Electromagnetic Launcher Technology, 5th, Sandestin, FL, Apr. 3-5, 1990, Proceedings

    NASA Astrophysics Data System (ADS)

    Gooden, Clarence E.

    1991-01-01

    The present conference on electromagnetic accelerators (EMAs) and railguns (RGs) discusses active-current management for four-rail RGs, the design of a compulsator-drive 60-caliber RG, EMA studies with augmented rails, muzzle-shunt augmentation of conventional RGs, effect of in-bore gas on RG performance, the distributed-energy store RG, plasma diagnostics for high power ignitron development, a review of EMA armature research, RG hybrid armatures, a new solid-armature design concept, and the electrodynamics of RG plasma armatures. Also discussed is RG modeling at speed using three-dimensional finite elements, power supply technology for EMAs, rotating machine power supplies for next-generation EMAs, advanced EMA power supplies with magnetic-flux compression, metal-to-metal switches for large currents, lightweight high-effiency energy-storage transformers, hypervelocity projectile development for EMAs, structural design issues for EMA projectiles, stiff RGs, a reinforced Al conductor for cryogenic applications, mass-stabilized projectile designs for EMA launch, indictively-commutated coilguns, an actively switched pulsed induction accelerator, a plasma gun-augmented electrothermal accelerator, a symmetrical rail accelerator, and a travelling-wave synchronous coil gun.

  10. Examining the Utility of Topic Models for Linguistic Analysis of Couple Therapy

    ERIC Educational Resources Information Center

    Doeden, Michelle A.

    2012-01-01

    This study examined the basic utility of topic models, a computational linguistics model for text-based data, to the investigation of the process of couple therapy. Linguistic analysis offers an additional lens through which to examine clinical data, and the topic model is presented as a novel methodology within couple and family psychology that…

  11. 3-D Modelling of Electromagnetic, Thermal, Mechanical and Metallurgical Couplings in Metal Forming Processes

    SciTech Connect

    Chenot, Jean-Loup; Bay, Francois

    2007-04-07

    The different stages of metal forming processes often involve - beyond the mechanical deformations processes - other physical coupled problems, such as heat transfer, electromagnetism or metallurgy. The purpose of this paper is to focus on problems involving electromagnetic couplings. After a brief recall on electromagnetic modeling, we shall then focus on induction heating processes and present some results regarding heat transfer, as well as mechanical couplings. A case showing coupling for metallurgic microstructure evolution will conclude this paper.

  12. PREFACE: 5th International Conference on Materials and Applications for Sensors and Transducers (IC-MAST2015)

    NASA Astrophysics Data System (ADS)

    Hristoforou, E.; Vlachos, D. S.; Giouroudi, I.; Kar-Narayan, S.; Potirakis, S.

    2016-03-01

    The 5th International Conference on Materials and Applications for Sensors and Transducers, Mykonos island, Greece, hosted about 110 oral and poster papers and more than 90 participants. IC-MAS, as an international annual conference which tries to meet the needs for various types of sensors, particularly those which may be manufactured by low cost methods (i.e. hybrid sensors, smart specialization devices, particular applications not necessarily requiring integrated micro-nano technologies), covering all types of materials and physical effects, appears to be a necessity. IC-MAST has been established as a high quality international conference by: I. Gathering together multinational researchers from all over the world, working in different materials for sensors and transducers and technical applications of sensors, but also in some cases in the management of the data coming from sensors and transducers. The careful selection of the conference place (like Aegean Sea, Budapest, Prague, Bilbao, Mykonos etc) allows for enjoying the local hospitality and sightseeing. II. Emphasizing in hybrid sensors and smart specialization devices produced by inexpensive methods, without excluding of course micro-nano technology, from all kinds of solid state, liquid and gaseous materials, as well as in particular transducer applications (design and development, as well as use of sensing data) III. Innovatively implementing the Virtual Paper Concept, allowing for large impact of research works presented in the conference by authors who either have no time or no funding support for visiting a conference; this year more than 12 virtual papers are presented in the 5th IC MAST, following a standardized procedure via the our robust and reliable Conference Site (www.icmast.net!) > IV. Allowing for lengthy technical and managerial discussions in terms of sensor, material and instrumentation development; furthermore, the different research groups gathered together are offered the particular

  13. Comparison of the USU ionospheric model with the UCL-Sheffield coupled thermospheric-ionospheric model

    NASA Technical Reports Server (NTRS)

    Sojka, J. J.; Schunk, R. W.; Rees, D.; Fuller-Rowell, T. J.; Moffett, R. J.; Quegan, S.

    1992-01-01

    Several physical models of the high-latitude ionosphere have been developed that describe the time-dependent evolution of the E- and F-region plasma density. The models require a variety of inputs, including solar EUV fluxes, magnetospheric convection, auroral precipitation, and neutral atmosphere. Of specific relevance to this study is how the neutral atmosphere is incorporated into the ionospheric models. For the USU ionospheric model, the neutral atmosphere is the MSIS 1986 empirical model, while for the UCL-Sheffield coupled thermospheric-ionospheric model the neutral atmosphere is computed simultaneously with the ionosphere. Both models were run for similar solar and magnetospheric conditions (solar maximum, moderate geomagnetic activity, and winter solstice). Solar maximum conditions ensured a strong coupling between the ionosphere and thermosphere, which provided the possibility of a large ionospheric difference between the two physical models. This was further enhanced by choosing winter conditions so that the densities were not dominated by sunlight. The comparison of the two models indicated that both models predict the same morphological features with similar ionospheric densities, generally within about 30 percent.

  14. Macracanthorhynchus hirudinaceus Eggs in Canine Coprolite from the Sasanian Era in Iran (4(th)/5(th) Century CE).

    PubMed

    Mowlavi, Gholamreza; Makki, Mahsasadat; Heidari, Zahra; Rezaeian, Mostafa; Mohebali, Mehdi; Araujo, Adauto; Boenke, Nicole; Aali, Abolfazl; Stollner, Thomas; Mobedi, Iraj

    2015-01-01

    Present paper is the second publication introducing the paleoparasitological findings from animal coprolites obtained from archeological site of Chehrabad salt mine in northwestern Iran. The current archeological site is located in northwest of Iran, dated to the Sassanian Era (4(th)/5(th) century CE). In the summer 2012 the carnivore coprolite was obtained within the layers in the mine and were thoroughly analyzed for parasites using TSP rehydration technique. Eggs of 0 were successfully retrieved from the examined coprolite and were confidently identified based on reliable references. Identifying of M. hirudinaceus eggs in paleofeces with clear appearance as demonstrated herein, is much due to appropriate preservation condition has been existed in the salt mine .The present finding could be regarded as the oldest acanthocephalan infection in Iran. PMID:26246822

  15. Macracanthorhynchus hirudinaceus Eggs in Canine Coprolite from the Sasanian Era in Iran (4th/5th Century CE)

    PubMed Central

    MOWLAVI, Gholamreza; MAKKI, Mahsasadat; HEIDARI, Zahra; REZAEIAN, Mostafa; MOHEBALI, Mehdi; ARAUJO, Adauto; BOENKE, Nicole; AALI, Abolfazl; STOLLNER, Thomas; MOBEDI, Iraj

    2015-01-01

    Present paper is the second publication introducing the paleoparasitological findings from animal coprolites obtained from archeological site of Chehrabad salt mine in northwestern Iran. The current archeological site is located in northwest of Iran, dated to the Sassanian Era (4th/5th century CE). In the summer 2012 the carnivore coprolite was obtained within the layers in the mine and were thoroughly analyzed for parasites using TSP rehydration technique. Eggs of 0 were successfully retrieved from the examined coprolite and were confidently identified based on reliable references. Identifying of M. hirudinaceus eggs in paleofeces with clear appearance as demonstrated herein, is much due to appropriate preservation condition has been existed in the salt mine .The present finding could be regarded as the oldest acanthocephalan infection in Iran. PMID:26246822

  16. Coupling geodynamic with thermodynamic modelling for reconstructions of magmatic systems

    NASA Astrophysics Data System (ADS)

    Rummel, Lisa; Kaus, Boris J. P.; White, Richard

    2016-04-01

    Coupling geodynamic with petrological models is fundamental for understanding magmatic systems from the melting source in the mantle to the point of magma crystallisation in the upper crust. Most geodynamic codes use very simplified petrological models consisting of a single, fixed, chemistry. Here, we develop a method to better track the petrological evolution of the source rock and corresponding volcanic and plutonic rocks by combining a geodynamic code with a thermodynamic model for magma generation and evolution. For the geodynamic modelling a finite element code (MVEP2) solves the conservation of mass, momentum and energy equations. The thermodynamic modelling of phase equilibria in magmatic systems is performed with pMELTS for mantle-like bulk compositions. The thermodynamic dependent properties calculated by pMELTS are density, melt fraction and the composition of the liquid and solid phase in the chemical system: SiO2-TiO2-Al2O3-Fe2O3-Cr2O3-FeO-MgO-CaO-Na2O-K2O-P2O5-H2O. In order to take into account the chemical depletion of the source rock with increasing melt extraction events, calculation of phase diagrams is performed in two steps: 1) With an initial rock composition density, melt fraction as well as liquid and solid composition are computed over the full upper mantle P-T range. 2) Once the residual rock composition (equivalent to the solid composition after melt extraction) is significantly different from the initial rock composition and the melt fraction is lower than a critical value, the residual composition is used for next calculations with pMELTS. The implementation of several melt extraction events take the change in chemistry into account until the solidus is shifted to such high temperatures that the rock cannot be molten anymore under upper mantle conditions. An advantage of this approach is that we can track the change of melt chemistry with time, which can be compared with natural constraints. In the thermo-mechanical code the

  17. Modeling of the Coupled Magnetospheric and Neutral Wind Dynamos

    NASA Technical Reports Server (NTRS)

    Thayer, Jeffrey P.

    1997-01-01

    the magnetosphere. The influence of the neutral wind was then determined not by estimating how much electric potential or current density it provides, but by determining the contribution of the neutral wind to the net electromagnetic energy transferred between the ionosphere and magnetosphere. The estimate of the net electromagnetic energy transfer and the role of the neutral winds proves to be a more fundamental quantity in studies of magnetosphere- ionosphere coupling also showed that by using electric and magnetic field measurements from the HILAT satellite, the Poynting flux could be a measurable quantity from polar-orbiting, low- altitude spacecraft. Through collaboration with Dr. Heelis and others at UTD and their expertise of the electric field measurements on the DE-B satellite, an extensive analysis was planned to determine the Poynting flux from the DE-B measurements in combination with a modeling effort to help interpret the observations taking into account the coupled magnetosphere-ionosphere.

  18. It takes a community to define a discipline: the 5th anniversary of Environmental Research Letters It takes a community to define a discipline: the 5th anniversary of Environmental Research Letters

    NASA Astrophysics Data System (ADS)

    Kammen, Dan

    2012-03-01

    commentary environment, a unique service in itself, and also a specific forum for research published in ERL. Individual topics often come up that warrant not only single articles, but collections of assessments, and ERL has published focus issues in key areas of environmental science including: tropical deforestation, wind energy, the Deepwater Horizon oil spill and climate engineering. ERL is currently publishing seven high-quality focus issues in cutting-edge areas such as arctic vegetation dynamics and cryospheric changes. Research letters appearing in ERL have received regular and significant coverage in the wider media, with several major news outlets and agencies choosing to cover ERL research, such as Nature, BBC News, New Scientist, The Guardian, Scientific American, Le Monde and many others. 4.The future community of ERL The process of community support will take many forms at ERL. The journal is growing—we have published the highest number of articles ever in a single volume in 2011 and are looking to continue this growth through into 2012. ERL had an over 50% increase in submissions from 2010 to 2011. One initiative to mark the journal's 5th anniversary was the 'Best articles' collection [1] a nominated compilation of articles showcasing the quality of published work in ERL as well as the subject area breadth. Co-authors of the five winning articles have been awarded free publication in ERL until the end of 2012. We can also see the open access model working, in that our articles are highly downloaded outside of the traditionally strong geographical areas of academia (North America and Western Europe), showing that the journal's readership is geographically diverse with high interest from Asia, South America and Africa. The journal is committed to progress and innovation; coming soon will be a set of new communication tools and online innovations, including: Video abstracts from the start of 2012 (for example, the video commentary published alongside this

  19. Exploring coupled 4D-Var data assimilation using an idealised atmosphere-ocean model

    NASA Astrophysics Data System (ADS)

    Smith, Polly; Fowler, Alison; Lawless, Amos; Haines, Keith

    2014-05-01

    The successful application of data assimilation techniques to operational numerical weather prediction and ocean forecasting systems has led to an increased interest in their use for the initialisation of coupled atmosphere-ocean models in prediction on seasonal to decadal timescales. Coupled data assimilation presents a significant challenge but offers a long list of potential benefits including improved use of near-surface observations, reduction of initialisation shocks in coupled forecasts, and generation of a consistent system state for the initialisation of coupled forecasts across all timescales. In this work we explore some of the fundamental questions in the design of coupled data assimilation systems within the context of an idealised one-dimensional coupled atmosphere-ocean model. The system is based on the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS) atmosphere model and a K-Profile Parameterisation (KKP) mixed layer ocean model developed by the National Centre for Atmospheric Science (NCAS) climate group at the University of Reading. It employs a strong constraint incremental 4D-Var scheme and is designed to enable the effective exploration of various approaches to performing coupled model data assimilation whilst avoiding many of the issues associated with more complex models. Working with this simple framework enables a greater range and quantity of experiments to be performed. Here, we will describe the development of our simplified single-column coupled atmosphere-ocean 4D-Var assimilation system and present preliminary results from a series of identical twin experiments devised to investigate and compare the behaviour and sensitivities of different coupled data assimilation methodologies. This includes comparing fully and weakly coupled assimilations with uncoupled assimilation, investigating whether coupled assimilation can eliminate or lessen initialisation shock in coupled model forecasts, and

  20. DRIFT-SCALE COUPLED PROCESSES (DST AND TH SEEPAGE) MODELS

    SciTech Connect

    J.T. Birkholzer; S. Mukhopadhyay

    2005-01-13

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  1. Coupling giant impacts and long-term evolution models

    NASA Astrophysics Data System (ADS)

    Golabek, G. J.; Emsenhuber, A.; Jutzi, M.; Gerya, T. V.; Asphaug, E. I.

    2015-10-01

    The crustal dichotomy [1] is the dominant geological feature on planet Mars. The exogenic approach to the origin of the crustal dichotomy [2-6] assumes that the northern lowlands correspond to a giant impact basin formed after primordial crust formation. However these simulations only consider the impact phase without studying the long-term repercussions of such a collision. The endogenic approach [7], suggesting a degree-1 mantle upwelling underneath the southern highlands [8-11], relies on a high Rayleigh number and a particular viscosity profile to form a low degree convective pattern within the geological constraints for the dichotomy formation. Such vigorous convection, however, results in continuous magmatic resurfacing, destroying the initially dichotomous crustal structure in the long-term. A further option is a hybrid exogenic-endogenic approach [12-15], which proposes an impact-induced magma ocean and subsequent superplume in the southern hemisphere. However these models rely on simple scaling laws to impose the thermal effects of the collision. Here we present the first results of impact simulations performed with a SPH code [16,17] serially coupled with geodynamical computations performed using the code I3VIS [18] to improve the latter approach and test it against observations. We are exploring collisions varying the impactor velocities, impact angles and target body properties, and are gauging the sensitivity to the handoff from SPH to I3VIS. As expected, our first results indicate the formation of a transient hemispherical magma ocean in the impacted hemisphere, and the merging of the cores. We also find that impact angle and velocity have a strong effect on the post-impact temperature field [5] and on the timescale and nature of core merger.

  2. Drift-Scale Coupled Processes (DST and TH Seepage) Models

    SciTech Connect

    J. Birkholzer; S. Mukhopadhyay

    2004-09-29

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report.

  3. Coupling giant impacts and longer-term evolution models

    NASA Astrophysics Data System (ADS)

    Golabek, Gregor; Jutzi, Martin; Emsenhuber, Alexandre; Gerya, Taras; Asphaug, Erik

    2016-04-01

    The crustal dichotomy is the dominant geological feature on planet Mars. The exogenic approach to the origin of the crustal dichotomy assumes that the northern lowlands correspond to a giant impact basin formed after primordial crust formation. However these simulations only consider the impact phase without studying the long-term repercussions of such a collision. The endogenic approach, suggesting a degree-1 mantle upwelling underneath the southern highlands, relies on a high Rayleigh number and a particular viscosity profile to form a low degree convective pattern within the geological constraints for the dichotomy formation. Such vigorous convection, however, results in continuous magmatic resurfacing, destroying the initially dichotomous crustal structure in the long-term. A further option is a hybrid exogenic-endogenic approach, which proposes an impact-induced magma ocean and subsequent superplume in the southern hemisphere. However these models rely on simple scaling laws to impose the thermal effects of the collision. Here we present the first results of impact simulations performed with a SPH code serially coupled with geodynamical computations performed using the code I3VIS to improve the latter approach and test it against observations. We are exploring collisions varying the impactor velocities, impact angles and target body properties, and are gauging the sensitivity to the handoff from SPH to I3VIS. As expected, our first results indicate the formation of a transient hemispherical magma ocean in the impacted hemisphere, and the merging of the cores. We also find that impact angle and velocity have a strong effect on the post-impact temperature field and on the timescale and nature of core merger.

  4. Coupled Subsurface-Surface-Atmosphere Feedbacks: Comparison of Two Coupled Modelling Platforms Applied to a Real Catchment

    NASA Astrophysics Data System (ADS)

    Rihani, J.; Larsen, M.; Stisen, S.; Refsgaard, J.; Jensen, K.; Simmer, C.

    2013-12-01

    In recent years, a number of simulation platforms with varying complexity which couple groundwater, land surface, and atmospheric models have emerged. These platforms are designed to include processes affecting energy fluxes and soil moisture variations at the land surface such as shallow groundwater, overland flow, and subsurface lateral flow. Previous studies demonstrate the sensitivity of atmospheric boundary layer dynamics and precipitation to land surface energy fluxes and groundwater dynamics, as well as the importance of capturing these interactions through coupled models. This study compares two distributed, physically-based, state-of-the-art hydrological modelling platforms: The ParFlow-CLM-COSMO platform TerrSysMP (Terrestrial System Modelling Platform), developed within the Transregional Collaborative Research Centre 32 (TR32), and the HIRHAM-MIKE SHE platform developed within the HOBE Centre for Hydrology and the HYdrological Modelling for Assessing Climate Change Impacts at differeNT Scales (HYACINTS) project. Both platforms differ in the handling of subsurface processes in the unsaturated zone as well as in the coupling approach used. We focus in particular on the inclusion of lateral flow in the unsaturated zone. While both models use the 3D groundwater flow equation in the saturated subsurface region, MIKE SHE implements the 1D Richards' equation to simulate water flow in the unsaturated zone using simulated dynamic groundwater levels from its saturated zone module. ParFlow within TerrSysMP on the other hand includes lateral flows in the unsaturated zone by implementing the 3D Richards' equation for the entire subsurface region. Some of the main questions investigated by this work are: 1. Is the dynamic approach of including lateral flows in the unsaturated zone needed within real watersheds? 2. If so, at which locations and times does it become important? 3. How does lateral flow in the unsaturated zone affect location and effectiveness of zones of

  5. Reliability and availability modeling of coupled communication networks - A simplified modeling approach

    NASA Technical Reports Server (NTRS)

    Shooman, Martin L.; Cortes, Eladio R.

    1991-01-01

    The network-complexity of LANs and of LANs that are interconnected by bridges and routers poses a challenging reliability-modeling problem. The present effort toward these problems' solution attempts to simplify them by reducing their number of states through truncation and state merging, as suggested by Shooman and Laemmel (1990). Through the use of state merging, it becomes possible to reduce the Bateman-Cortes 161 state model to a two state model with a closed-form solution. In the case of coupled networks, a technique which allows for problem-decomposition must be used.

  6. Analysis of Neural-BOLD Coupling Through Four Models of the Neural Metabolic Demand

    PubMed Central

    Tyler, Christopher W.; Likova, Lora T.; Nicholas, Spero C.

    2015-01-01

    The coupling of the neuronal energetics to the blood-oxygen-level-dependent (BOLD) response is still incompletely understood. To address this issue, we compared the fits of four plausible models of neurometabolic coupling dynamics to available data for simultaneous recordings of the local field potential and the local BOLD response recorded from monkey primary visual cortex over a wide range of stimulus durations. The four models of the metabolic demand driving the BOLD response were: direct coupling with the overall LFP; rectified coupling to the LFP; coupling with a slow adaptive component of the implied neural population response; and coupling with the non-adaptive intracellular input signal defined by the stimulus time course. Taking all stimulus durations into account, the results imply that the BOLD response is most closely coupled with metabolic demand derived from the intracellular input waveform, without significant influence from the adaptive transients and nonlinearities exhibited by the LFP waveform. PMID:26696806

  7. Emergencies planning and response: Coupling an exposure model with different atmospheric dispersion models

    NASA Astrophysics Data System (ADS)

    Sanchez, E. Y.; Colman Lerner, J. E.; Porta, A.; Jacovkis, P. M.

    2013-11-01

    Information on spatial and time dependent concentration patterns of hazardous substances, as well as on the potential effects on population, is necessary to assist in chemical emergency planning and response. To that end, some models predict transport and dispersion of hazardous substances, and others estimate potential effects upon exposed population. Taken together, both groups constitute a powerful tool to estimate vulnerable regions and to evaluate environmental impact upon affected populations. The development of methodologies and models with direct application to the context in which we live allows us to draft a more clear representation of the risk scenario and, hence, to obtain the adequate tools for an optimal response. By means of the recently developed DDC (Damage Differential Coupling) exposure model, it was possible to optimize, from both the qualitative and the quantitative points of view, the estimation of the population affected by a toxic cloud, because the DDC model has a very good capacity to couple with different atmospheric dispersion models able to provide data over time. In this way, DDC analyzes the different concentration profiles (output from the transport model) associating them with some reference concentration to identify risk zones. In this work we present a disaster scenario in Chicago (USA), by coupling DDC with two transport models of different complexity, showing the close relationship between a representative result and the run time of the models. In the same way, it becomes evident that knowing the time evolution of the toxic cloud and of the affected regions significantly improves the probability of taking the correct decisions on planning and response facing the emergency.

  8. FOREWORD: The 5th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas

    NASA Astrophysics Data System (ADS)

    Tchang-Brillet, Wad Lydia; Wyart, Jean-François; Zeippen, Claude

    1996-01-01

    The 5th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas was held in Meudon, France, from August 28 to 31 1995. It was the fifth in a series started by the Atomic Spectroscopic Group at the University of Lund, Sweden, in 1983. Then followed the meetings in Toledo, USA, Amsterdam, The Nether- lands and Gaithersburg, USA, with a three year period. The original title of the series ended with "... for Astrophysics and Fusion Research" and became more general with the 4th colloquium in Gaithersburg. The purpose of the present meeting was, in line with tradition, to bring together "producers" and "users" of atomic data so as to ensure optimal coordination. Atomic physicists who study the structure of atoms and their radiative and collisional properties were invited to explain the development of their work, emphasizing the possibilities of producing precise transition wavelengths and relative line intensities. Astrophysicists and laboratory plasma physicists were invited to review their present research interests and the context in which atomic data are needed. The number of participants was about 70 for the first three meetings, then exploded to 170 at Gaithersburg. About 140 participants, coming from 13 countries, attended the colloquium in Meudon. This large gathering was partly due to a number of participants from Eastern Europe larger than in the past, and it certainly showed a steady interest for interdisciplinary exchanges between different communities of scientists. This volume includes all the invited papers given at the conference and, in the appendix, practical information on access to some databases. All invited speakers presented their talks aiming at good communication between scientists from different backgrounds. A separate bound volume containing extended abstracts of the poster papers has been published by the Publications de l'Observatoire de Paris, (Meudon 1996), under the responsibility of

  9. Modeling and Simulation of Plasmonic Lithography Process with Coupling Between Electromagnetic Wave Model, Phase Field Model and Heat Transfer Model

    NASA Astrophysics Data System (ADS)

    Chao, Ion Hong

    Plasmonic lithography may become a mainstream nano-fabrication technique in the future. Experimental results show that feature size with 22 nm resolution can be achieved by plasmonic lithography [1]. In Pan's experiment, a plasmonic lens is used to focus the laser energy with resolution much higher than the diffraction limit and thereby create features in the thermally sensitive material layer. The energy transport mechanisms are still not fully understood in the plasmonic lithography process. In order to predict the lithography resolution and explore the energy transport mechanisms involved in the process, customized electromagnetic wave and heat transfer models were developed in COMSOL. Parametric studies on both operating parameters and material properties were performed to optimize the lithography process. The parametric studies showed that the lithography process can be improved by either reducing the thickness of the phase change material layer or using a material with smaller real refractive index for that layer. Moreover, a phase field model was also developed in COMSOL to investigate the phase separation mechanism involved in creating features in plasmonic lithography. By including the effect of bond energy in this model, phase separation was obtained from the phase field model under isothermal conditions with speed much faster than the classical diffusion theory can predict. Mathematical transformation was applied to the phase field model, which was necessary for solving numerical issues to obtain the result of complete phase separation. Under isothermal conditions, the phase field model confirmed the fact that the speed of phase separation is determined by both particle mobility and thermodynamic driving force. The fast phase separation in the phase change material is mainly due to strong thermodynamic driving force from the bond energy. The phase field model was coupled with a heat transfer model to simulate phase separation under laser pulse heating

  10. A Theoretical Model for Thin Film Ferroelectric Coupled Microstripline Phase Shifters

    NASA Technical Reports Server (NTRS)

    Romanofsky, R. R.; Quereshi, A. H.

    2000-01-01

    Novel microwave phase shifters consisting of coupled microstriplines on thin ferroelectric films have been demonstrated recently. A theoretical model useful for predicting the propagation characteristics (insertion phase shift, dielectric loss, impedance, and bandwidth) is presented here. The model is based on a variational solution for line capacitance and coupled strip transmission line theory.

  11. Assimilation of MGS Data Into a Coupled GCM-Mesoscale Model of the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Rafkin, Scot C. R.; Haberle, Robert (Technical Monitor)

    2001-01-01

    The project sought to develop a coupled GCM-mesoscale model and to assimilate Mars Global Surveyor (MGS) data into the coupled model. To achieve the project goals, four specific research activities were proposed. These activities are reiterated for completeness and the progress in each of the activities is noted in future sections of this report.

  12. Topic models: A novel method for modeling couple and family text data

    PubMed Central

    Atkins, David C.; Rubin, Tim N.; Steyvers, Mark; Doeden, Michelle A.; Baucom, Brian R.; Christensen, Andrew

    2012-01-01

    Couple and family researchers often collect open-ended linguistic data – either through free response questionnaire items or transcripts of interviews or therapy sessions. Because participant's responses are not forced into a set number of categories, text-based data can be very rich and revealing of psychological processes. At the same time it is highly unstructured and challenging to analyze. Within family psychology analyzing text data typically means applying a coding system, which can quantify text data but also has several limitations, including the time needed for coding, difficulties with inter-rater reliability, and defining a priori what should be coded. The current article presents an alternative method for analyzing text data called topic models (Steyvers & Griffiths, 2006), which has not yet been applied within couple and family psychology. Topic models have similarities with factor analysis and cluster analysis in that topic models identify underlying clusters of words with semantic similarities (i.e., the “topics”). In the present article, a non-technical introduction to topic models is provided, highlighting how these models can be used for text exploration and indexing (e.g., quickly locating text passages that share semantic meaning) and how output from topic models can be used to predict behavioral codes or other types of outcomes. Throughout the article a collection of transcripts from a large couple therapy trial (Christensen et al., 2004) is used as example data to highlight potential applications. Practical resources for learning more about topic models and how to apply them are discussed. PMID:22888778

  13. Numerical prediction of subsidence with coupled geomechanical-hydrological modeling

    SciTech Connect

    Girrens, S.P.; Anderson, C.A.; Bennett, J.G.; Kramer, M.

    1981-01-01

    A coupled finite element geomechanical-hydrology code is currently under development for application to the problem of predicting groundwater disturbances associated with mine subsidence. The structural-fluid coupling is addressed by calculating the subsided mine geometry, with emphasis placed on determining the strata disturbance and locating damaged regions, for input into a hydrology code, which determines localized volume flow rates and aquifer fluctuations. Benefits from coupling will be best realized when field measurements, an additional aspect of the study concurrent with analytical investigations, indicating the relationship between increasing rock strain and increasing permeability are incorporated into hydraulic material descriptions. Hydrologic and structural calculations are presented to demonstrate computational capabilities applicable to mine subsidence.

  14. Strategies for the coupling of global and local crystal growth models

    NASA Astrophysics Data System (ADS)

    Derby, Jeffrey J.; Lun, Lisa; Yeckel, Andrew

    2007-05-01

    The modular coupling of existing numerical codes to model crystal growth processes will provide for maximum effectiveness, capability, and flexibility. However, significant challenges are posed to make these coupled models mathematically self-consistent and algorithmically robust. This paper presents sample results from a coupling of the CrysVUn code, used here to compute furnace-scale heat transfer, and Cats2D, used to calculate melt fluid dynamics and phase-change phenomena, to form a global model for a Bridgman crystal growth system. However, the strategy used to implement the CrysVUn-Cats2D coupling is unreliable and inefficient. The implementation of under-relaxation within a block Gauss-Seidel iteration is shown to be ineffective for improving the coupling performance in a model one-dimensional problem representative of a melt crystal growth model. Ideas to overcome current convergence limitations using approximations to a full Newton iteration method are discussed.

  15. Sensitivity of Air-sea Exchange In A Regional Scale Coupled Ice/ocean/atmosphere Model

    NASA Astrophysics Data System (ADS)

    Schrum, C.; Hübner, U.; Jacob, D.; Podzun, R.

    The sub-systems ice, ocean and atmosphere are coupled on the global as well as the regional scale. However, regional coupled modeling is only in the beginning, full cou- pled models which are able to describe the interaction on the regional scale and the feedback mechanism are rare at the moment. For the North Sea and the Baltic Sea such a coupled model has been developed and exemplary integrated over a full seasonal cy- cle. By comparison of different regionalization studies the impact of the regional at- mospheric modeling and coupling on the air sea fluxes have been investigated. It was shown that the regionalization as well as the coupling show strong influence on the air/sea fluxes and thus on the oceanic conditions. Further problems in regional mod- eling like the description of storm track variability and its influence on the regional ocean model were identified.

  16. Flux limiters in the coupling of radiation and hydrodynamic models

    NASA Astrophysics Data System (ADS)

    Seaid, M.; Klar, A.; Dubroca, B.

    2004-07-01

    Two numerical approximations to radiative heat transfer problem based on asymptotic and entropy approaches are proposed for hydrodynamics radiation coupling. We compare the radiative fluxes between the two approaches and we show that the coupling based on the entropy approach is flux limited, while the other approach does not preserve this condition. Relaxation schemes are considered for the hydrodynamic part, and an iterative procedure is used for radiation. The new splitting algorithm avoids the use of Riemann solvers and Newton iterations. Numerical examples are carried out on two and three dimensional problems.

  17. On the inability of magnetically constricted transition regions to account for the 10 to the 5th to 10 to the 6th K plasma in the quiet solar atmosphere

    NASA Technical Reports Server (NTRS)

    Dowdy, James F., Jr.; Moore, Ronald L.; Emslie, A. Gordon

    1987-01-01

    Static models of the plasma in the quiet solar atmosphere incorporating not only conduction and radiation but also the effects of large magnetic constrictions are examined. It is found that the bulk of the solar plasma at temperatures below 7 x 10 to the 5th K cannot be produced by a conductive transition region when it is modeled by flux tubes with constriction compatible with observations. The present findings suggest that the major portion of the UEV plasma may be maintained in an ensemble of small, individual magnetic loops located within the supergranular network and having peak temperatures ranging from chromospheric to coronal values.

  18. Coupled atmosphere-ocean variational data assimilation in the presence of model error

    NASA Astrophysics Data System (ADS)

    Fowler, Alison; Lawless, Amos

    2016-04-01

    Atmosphere-only and ocean-only variational data assimilation (DA) schemes are able to use window lengths that are optimal for the error growth rate, non-linearity and observation density of the respective systems. Typical window lengths are 6-12 hours for the atmosphere and 2-10 days for the ocean. However, in the implementation of coupled DA schemes it has been necessary to match the window length of the ocean to that of the atmosphere, which may potentially sacrifice the accuracy of the ocean analysis in order to provide a more balanced coupled state. This work investigates how extending the window length in the presence of model error affects both the analysis of the coupled state and the initialized forecast when using coupled DA with differing degrees of coupling. Results are illustrated using an idealized single column model of the coupled atmosphere-ocean system. It is found that the analysis error from an uncoupled DA scheme can be smaller than that from a coupled analysis at the initial time, due to faster error growth in the coupled system. However, this does not necessarily lead to a more accurate forecast, due to imbalances in the coupled state. Instead coupled DA is more able to change the initial state to allow for model errors and thus produce a more accurate forecast. The effect of model error is potentially most detrimental in the weakly coupled formulation due to the inconsistency between the coupled model used in the outer loop and uncoupled models used in the inner loop of the incremental scheme.

  19. The use of coupled atmospheric and hydrological models for water-resources management in headwater basins

    USGS Publications Warehouse

    Leavesley, G.; Hay, L.

    1998-01-01

    Coupled atmospheric and hydrological models provide an opportunity for the improved management of water resources in headwater basins. Issues currently limiting full implementation of coupled-model methodologies include (a) the degree of uncertainty in the accuracy of precipitation and other meteorological variables simulated by atmospheric models, and (b) the problem of discordant scales between atmospheric and bydrological models. Alternative methodologies being developed to address these issues are reviewed.

  20. Development of An Unstructured Storm Surge-waves-tide Coupled Model And Its Application

    NASA Astrophysics Data System (ADS)

    Feng, X.

    2015-12-01

    An unstructured storm surge-waves-tide coupled model, which was coupled through the Model Coupling Toolkit (MCT), was developed based on the ADCIRC (Advanced Circulation model) ocean model and SWAN (Simulating Waves Nearshore) wave model. The developed coupled model has high resolution in the coast area and can be run efficiently. By comparing with the existing ADCIRC and SWAN coupled model, which was coupled directly not through the MCT, the newly developed one can increase the simulation efficiency by 26.4 percent, when the computational grid and coupling processes of the two coupled model were the same. The coupled model was used to simulate the storm surge and waves during the process of typhoon "Usagi" which formed in the western Pacific on September 17, 2013 and made landfall at Shanwei in Guangdong province. Three numerical experiments were done in the simulation to study the effect of wave-current interaction on the storm surge and waves. Results show that the coupled model can simulate the storm surge and waves well when considering the wave induced radiation stress, the wave effect on the wind stress drag coefficient and the modulation of current and water level on the waves. During the process of typhoon "Usagi" the effect of wave radiation stress can result in a maximum of 0.75m increase in the extreme storm surge, and the wave induced wind stress can cause a -0.82~0.49m change of the extreme storm surge near the coastal area. This study is valuable to the study of hurricane storm surge disaster assessment and the development of the operational storm surge prediction technique.

  1. Finding the driver of local ocean-atmosphere coupling in reanalyses and CMIP5 climate models

    NASA Astrophysics Data System (ADS)

    Ruiz-Barradas, Alfredo; Kalnay, Eugenia; Peña, Malaquías; BozorgMagham, Amir E.; Motesharrei, Safa

    2016-06-01

    Identification of the driver of coupled anomalies in the climate system is of great importance for a better understanding of the system and for its use in predictive efforts with climate models. The present analysis examines the robustness of a physical method proposed three decades ago to identify coupled anomalies as of atmospheric or oceanic origin by analyzing 850 mb vorticity and sea surface temperature anomalies. The method is then used as a metric to assess the coupling in climate simulations and a 30-year hindcast from models of the CMIP5 project. Analysis of the frequency of coupled anomalies exceeding one standard deviation from uncoupled NCEP/NCAR and ERA-Interim and partially coupled CFSR reanalyses shows robustness in the main results: anomalies of oceanic origin arise inside the deep tropics and those of atmospheric origin outside of the tropics. Coupled anomalies occupy similar regions in the global oceans independently of the spatiotemporal resolution. Exclusion of phenomena like ENSO, NAO, or AMO has regional effects on the distribution and origin of coupled anomalies; the absence of ENSO decreases anomalies of oceanic origin and favors those of atmospheric origin. Coupled model simulations in general agree with the distribution of anomalies of atmospheric and oceanic origin from reanalyses. However, the lack of the feedback from the atmosphere to the ocean in the AMIP simulations reduces substantially the number of coupled anomalies of atmospheric origin and artificially increases it in the tropics while the number of those of oceanic origin outside the tropics is also augmented. Analysis of a single available 30-year hindcast surprisingly indicates that coupled anomalies are more similar to AMIP than to coupled simulations. Differences in the frequency of coupled anomalies between the AMIP simulations and the uncoupled reanalyses, and similarities between the uncoupled and partially coupled reanalyses, support the notion that the nature of the

  2. A poroelastic model coupled to a fluid network with applications in lung modelling.

    PubMed

    Berger, Lorenz; Bordas, Rafel; Burrowes, Kelly; Grau, Vicente; Tavener, Simon; Kay, David

    2016-01-01

    We develop a lung ventilation model based on a continuum poroelastic representation of lung parenchyma that is strongly coupled to a pipe network representation of the airway tree. The continuous system of equations is discretized using a low-order stabilised finite element method. The framework is applied to a realistic lung anatomical model derived from computed tomography data and an artificially generated airway tree to model the conducting airway region. Numerical simulations produce physiologically realistic solutions and demonstrate the effect of airway constriction and reduced tissue elasticity on ventilation, tissue stress and alveolar pressure distribution. The key advantage of the model is the ability to provide insight into the mutual dependence between ventilation and deformation. This is essential when studying lung diseases, such as chronic obstructive pulmonary disease and pulmonary fibrosis. Thus the model can be used to form a better understanding of integrated lung mechanics in both the healthy and diseased states. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26100614

  3. Modeling the tropical Pacific Ocean using a regional coupled climate model

    NASA Astrophysics Data System (ADS)

    Fu, Weiwei; Zhou, Guangqing; Wang, Huijun

    2006-12-01

    A high-resolution tropical Pacific general circulation model (GCM) coupled to a global atmospheric GCM is described in this paper. The atmosphere component is the 5° × 4° global general circulation model of the Institute of Atmospheric Physics (IAP) with 9 levels in the vertical direction. The ocean component with a horizontal resolution of 0.5°, is based on a low-resolution model (2° × 1° in longitude-latitude). Simulations of the ocean component are first compared with its previous version. Results show that the enhanced ocean horizontal resolution allows an improved ocean state to be simulated: this involves (1) an apparent decrease in errors in the tropical Pacific cold tongue region, which exists in many ocean models, (2) more realistic large-scale flows, and (3) an improved ability to simulate the interannual variability and a reduced root mean square error (RMSE) in a long time integration. In coupling these component models, a monthly “linear-regression” method is employed to correct the model’s exchanged flux between the sea and the atmosphere. A 100-year integration conducted with the coupled GCM (CGCM) shows the effectiveness of such a method in reducing climate drift. Results from years 70 to 100 are described. The model produces a reasonably realistic annual cycle of equatorial SST. The large SSTA is confined to the eastern equatorial Pacific with little propagation. Irregular warm and cold events alternate with a broad spectrum of periods between 24 and 50 months, which is very realistic. But the simulated variability is weaker than the observed and is also asymmetric in the sense of the amplitude of the warm and cold events.

  4. A hydrodynamics-reaction kinetics coupled model for evaluating bioreactors derived from CFD simulation.

    PubMed

    Wang, Xu; Ding, Jie; Guo, Wan-Qian; Ren, Nan-Qi

    2010-12-01

    Investigating how a bioreactor functions is a necessary precursor for successful reactor design and operation. Traditional methods used to investigate flow-field cannot meet this challenge accurately and economically. Hydrodynamics model can solve this problem, but to understand a bioreactor in sufficient depth, it is often insufficient. In this paper, a coupled hydrodynamics-reaction kinetics model was formulated from computational fluid dynamics (CFD) code to simulate a gas-liquid-solid three-phase biotreatment system for the first time. The hydrodynamics model is used to formulate prediction of the flow field and the reaction kinetics model then portrays the reaction conversion process. The coupled model is verified and used to simulate the behavior of an expanded granular sludge bed (EGSB) reactor for biohydrogen production. The flow patterns were visualized and analyzed. The coupled model also demonstrates a qualitative relationship between hydrodynamics and biohydrogen production. The advantages and limitations of applying this coupled model are discussed. PMID:20727741

  5. Modelling soil-plant-atmosphere interactions by coupling the regional weather model WRF to mechanistic plant models

    NASA Astrophysics Data System (ADS)

    Klein, C.; Hoffmann, P.; Priesack, E.

    2012-04-01

    Climate change causes altering distributions of meteorological factors influencing plant growth and its interactions between the land surface and the atmosphere. Recent studies show, that uncertainties in regional and global climate simulations are also caused by lacking descriptions of the soil-plant-atmosphere system. Therefore, we couple a mechanistic soil-plant model to a regional climate and forecast model. The detailed simulation of the water and energy exchanges, especially the transpiration of grassland and forests stands, are the key features of the modelling framework. The Weather Research and Forecasting model (WRF) (Skamarock 2008) is an open source mesoscale numerical weather prediction model. The WRF model was modified in a way, to either choose its native, static land surface model NOAH or the mechanistic eco-system model Expert-N 5.0 individually for every single grid point within the simulation domain. The Expert-N 5.0 modelling framework provides a highly modular structure, enabling the development and use of a large variety of different plant and soil models, including heat transfer, nitrogen uptake/turnover/transport as well as water uptake/transport and crop management. To represent the key landuse types grassland and forest, we selected two mechanistic plant models: The Hurley Pasture model (Thornley 1998) and a modified TREEDYN3 forest simulation model (Bossel 1996). The models simulate plant growth, water, nitrogen and carbon flows for grassland and forest stands. A mosaic approach enables Expert-N to use high resolution land use data e.g. CORINE Land Cover data (CLC, 2006) for the simulation, making it possible to simulate different land use distributions within a single grid cell. The coupling results are analyzed for plausibility and compared with the results of the default land surface model NOAH (Fei Chen and Jimy Dudhia 2010). We show differences between the mechanistic and the static model coupling, with focus on the feedback effects

  6. Coupled model of INM-IO global ocean model, CICE sea ice model and SCM OIAS framework

    NASA Astrophysics Data System (ADS)

    Bayburin, Ruslan; Rashit, Ibrayev; Konstantin, Ushakov; Vladimir, Kalmykov; Gleb, Dyakonov

    2015-04-01

    Status of coupled Arctic model of ocean and sea ice is presented. Model consists of INM IO global ocean component of high resolution, Los Alamos National Laboratory CICE sea ice model and a framework SCM OIAS for the ocean-ice-atmosphere-land coupled modeling on massively-parallel architectures. Model is currently under development at the Institute of Numerical Mathematics (INM), Hydrometeorological Center (HMC) and P.P. Shirshov Institute of Oceanology (IO). Model is aimed at modeling of intra-annual variability of hydrodynamics in Arctic and. The computational characteristics of the world ocean-sea ice coupled model governed by SCM OIAS are presented. The model is parallelized using MPI technologies and currently can use efficiently up to 5000 cores. Details of programming implementation, computational configuration and physical phenomena parametrization are analyzed in terms of intercoupling complex. Results of five year computational experiment of sea ice, snow and ocean state evolution in Arctic region on tripole grid with horizontal resolution of 3-5 kilometers, closed by atmospheric forcing field from repeating "normal" annual course taken from CORE1 experiment data base are presented and analyzed in terms of the state of vorticity and warm Atlantic water expansion.

  7. Identification of a coupled flapping/inflow model for the PUMA helicopter from flight test data

    NASA Technical Reports Server (NTRS)

    Du Val, Ronald; Bruhis, Ofer; Green, John

    1989-01-01

    A model validation procedure is applied to a coupled flapping/inflow model of a PUMA helicopter blade. The structure of the baseline model is first established. Model structure and flight test data are checked for consistency. Parameters of the model are then identified from the flight test data.

  8. Scenario Analysis With Economic-Energy Systems Models Coupled to Simple Climate Models

    NASA Astrophysics Data System (ADS)

    Hanson, D. A.; Kotamarthi, V. R.; Foster, I. T.; Franklin, M.; Zhu, E.; Patel, D. M.

    2008-12-01

    Here, we compare two scenarios based on Stanford University's Energy Modeling Forum Study 22 on global cooperative and non-cooperative climate policies. In the former, efficient transition paths are implemented including technology Research and Development effort, energy conservation programs, and price signals for greenhouse gas (GHG) emissions. In the non-cooperative case, some countries try to relax their regulations and be free riders. Total emissions and costs are higher in the non-cooperative scenario. The simulations, including climate impacts, run to the year 2100. We use the Argonne AMIGA-MARS economic-energy systems model, the Texas AM University's Forest and Agricultural Sector Optimization Model (FASOM), and the University of Illinois's Integrated Science Assessment Model (ISAM), with offline coupling between the FASOM and AMIGA-MARS and an online coupling between AMIGA-MARS and ISAM. This set of models captures the interaction of terrestrial systems, land use, crops and forests, climate change, human activity, and energy systems. Our scenario simulations represent dynamic paths over which all the climate, terrestrial, economic, and energy technology equations are solved simultaneously Special attention is paid to biofuels and how they interact with conventional gasoline/diesel fuel markets. Possible low-carbon penetration paths are based on estimated costs for new technologies, including cellulosic biomass, coal-to-liquids, plug-in electric vehicles, solar and nuclear energy. We explicitly explore key uncertainties that affect mitigation and adaptation scenarios.

  9. Coupled Particle Transport and Pattern Formation in a Nonlinear Leaky-Box Model

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.; El-Nemr, K. W.; Baird, J. K.

    2009-01-01

    Effects of particle-particle coupling on particle characteristics in nonlinear leaky-box type descriptions of the acceleration and transport of energetic particles in space plasmas are examined in the framework of a simple two-particle model based on the Fokker-Planck equation in momentum space. In this model, the two particles are assumed coupled via a common nonlinear source term. In analogy with a prototypical mathematical system of diffusion-driven instability, this work demonstrates that steady-state patterns with strong dependence on the magnetic turbulence but a rather weak one on the coupled particles attributes can emerge in solutions of a nonlinearly coupled leaky-box model. The insight gained from this simple model may be of wider use and significance to nonlinearly coupled leaky-box type descriptions in general.

  10. Progress and Challenges in Coupled Ice-Sheet/Climate Modeling with CESM

    NASA Astrophysics Data System (ADS)

    Fyke, J. G.; Sacks, W.; Vizcaino, M.; Lipscomb, W. H.; Price, S. F.

    2014-12-01

    Bidirectional coupling of ice sheet models and climate models opens the door to research of ice-sheet/climate interaction at a global scale. However, difficulties encountered in achieving this coupling have proven non-trivial and include both: 1) Technical challenges. Ocean and atmosphere model components cannot easily handle dynamic boundaries; land surface model components cannot easily simulate exposed glacial ice, firn evolution, or evolving land surfaces; coupling infrastructure cannot easily accept new earth system components; and ice sheet models typically operate at an order of magnitude higher spatial resolution than climate models and on regional domains, and require very long integrations to reach an equilibrium state. 2) Scientific challenges. The glaciological modeling and climate modeling communities often work on topics that cover very different spatiotemporal scales; carry out research using very different models and with very different modeling paradigms; and do not consider coupled ice-sheet/climate behavior across the various ice-sheet/climate physical interfaces. These technical and scientific challenges are being tackled within the Community Earth System Model. The resulting coupled architecture ("CESM-CISM") is now capable of simulating the Greenland ice sheet (GrIS) in the climate system. The model includes a relatively sophisticated representation of surface mass balance (SMB), explicit resolution of important ice-sheet climate communication pathways, and prognostic ice dynamics. First results, underpinned by modelled SMB validation, have explored changes in GrIS mean SMB and its variability, partially-coupled GrIS evolution, and emergence of an anthropogenic signal in SMB under RCP8.5 climate forcing. Ongoing work with the evolving CESM-CISM will set the stage for fully-coupled simulations of Greenland in past and future climates, and also for potential integration of the Antarctic ice sheet into a true coupled modeling framework.

  11. Ice-ocean-atmosphere coupling in the Regional Arctic System Model

    NASA Astrophysics Data System (ADS)

    Roberts, A.; Brunke, M.; Cassano, J. J.; Craig, A.; Duvivier, A.; Hughes, M.; Maslowski, W.; Nijssen, B.; Osinski, R.

    2013-12-01

    This work demonstrates the sea ice model performance in the latest version of the Regional Arctic System Model (RASM), which is a fully coupled regional climate model developed by a group of U.S. institutions as a regional counterpart to the Community Earth System Model (CESM). RASM is comprised of the Parallel Ocean Program (POP), Los Alamos Sea Ice Model (CICE), Variable Infiltration Capacity (VIC) hydrology model and the Weather Research and Forecasting (WRF) Model. It uses the same coupling infrastructure as CESM, with important physics differences that we have found to be important in our high-resolution model. Model evaluations using SSM/I sea ice extent and concentration, ICESat sea ice thickness measurements, ice-ocean buoys, and satellite retrievals of sea ice drift and deformation, lead us to adjust the standard CESM Monin-Obukhov ice-ocean-atmospheric coupling and ice-ocean stress term used for coupling with POP-CICE at eddy-permitting resolution of 1/12 degree with the 50km resolution WRF and VIC models. Evaluation metrics based on scaling laws and wavelet techniques illustrate that 20-minute coupling produces deformation and drift statistics commensurate with high temporal and spatial resolution measurements. However, dynamical interactions are compromised when typical radiative settings are used as in stand-alone POP-CICE and WRF. This highlights the limitations of surface polar boundary conditions in stand-alone models relative to fully coupled interactions. Our results suggest that use of uncoupled models as testbeds for improved polar components of next-generation global Earth System Models may introduce biases into fully coupled systems, and these can be reduced using a regional coupled climate system model, such as RASM, as a testbed instead.

  12. Full wave propagation modelling in view to integrated ICRH wave coupling/RF sheaths modelling

    NASA Astrophysics Data System (ADS)

    Jacquot, Jonathan; Bobkov, Volodymyr; Colas, Laurent; Heuraux, Stéphane; Křivská, Alena; Lu, Lingfeng; Noterdaeme, Jean-Marie

    2015-12-01

    RF sheaths rectification can be the reason for operational limits for Ion Cyclotron Range of Frequencies (ICRF) heating systems via impurity production or excessive heat loads. To simulate this process in realistic geometry, the Self-consistent Sheaths and Waves for Ion Cyclotron Heating (SSWICH) code is a minimal set of coupled equations that computes self-consistently wave propagation and DC plasma biasing. The present version of its wave propagation module only deals with the Slow Wave assumed to be the source of RF sheath oscillations. However the ICRF power coupling to the plasma is due to the fast wave (FW). This paper proposes to replace this one wave equation module by a full wave module in either 2D or 3D as a first step towards integrated modelling of RF sheaths and wave coupling. Since the FW is propagative in the main plasma, Perfectly Matched Layers (PMLs) adapted for plasmas were implemented at the inner side of the simulation domain to absorb outgoing waves and tested numerically with tilted B0 in Cartesian geometry, by either rotating the cold magnetized plasma dielectric tensors in 2D or rotating the coordinate vector basis in 3D. The PML was further formulated in cylindrical coordinates to account for for the toroidal curvature of the plasma. Toroidal curvature itself does not seem to change much the coupling. A detailed 3D geometrical description of Tore Supra and ASDEX Upgrade (AUG) antennas was included in the coupling code. The full antenna structure was introduced, since its toroidal symmetry with respect to the septum plane is broken (FS bars, toroidal phasing, non-symmetrical structure). Reliable convergence has been obtained with the density profile up to the leading edge of antenna limiters. Parallel electric field maps have been obtained as an input for the present version of SSWICH.

  13. ENSO Simulation in Coupled Ocean-Atmosphere Models: Are the Current Models Better?

    SciTech Connect

    AchutaRao, K; Sperber, K R

    2005-04-29

    Maintaining a multi-model database over a generation or more of model development provides an important framework for assessing model improvement. Using control integrations, we compare the simulation of the El Nino/Southern Oscillation (ENSO), and its extratropical impact, in models developed for the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report with models developed in the late 1990's (the so-called Coupled Model Intercomparison Project-2 [CMIP2] models). The IPCC models tend to be more realistic in representing the frequency with which ENSO occurs, and they are better at locating enhanced temperature variability over the eastern Pacific Ocean. When compared with reanalyses, the IPCC models have larger pattern correlations of tropical surface air temperature than do the CMIP2 models during the boreal winter peak phase of El Nino. However, for sea-level pressure and precipitation rate anomalies, a clear separation in performance between the two vintages of models is not as apparent. The strongest improvement occurs for the modeling groups whose CMIP2 model tended to have the lowest pattern correlations with observations. This has been checked by subsampling the multi-century IPCC simulations in a manner to be consistent with the single 80-year time segment available from CMIP2. Our results suggest that multi-century integrations may be required to statistically assess model improvement of ENSO. The quality of the El Nino precipitation composite is directly related to the fidelity of the boreal winter precipitation climatology, highlighting the importance of reducing systematic model error. Over North America distinct improvement of El Nino forced boreal winter surface air temperature, sea-level pressure, and precipitation rate anomalies in the IPCC models occurs. This improvement, is directly proportional to the skill of the tropical El Nino forced precipitation anomalies.

  14. Linking Tectonics and Surface Processes through SNAC-CHILD Coupling: Preliminary Results Towards Interoperable Modeling Frameworks

    NASA Astrophysics Data System (ADS)

    Choi, E.; Kelbert, A.; Peckham, S. D.

    2014-12-01

    We demonstrate that code coupling can be an efficient and flexible method for modeling complicated two-way interactions between tectonic and surface processes with SNAC-CHILD coupling as an example. SNAC is a deep earth process model (a geodynamic/tectonics model), built upon a scientific software framework called StGermain and also compatible with a model coupling framework called Pyre. CHILD is a popular surface process model (a landscape evolution model), interfaced to the CSDMS (Community Surface Dynamics Modeling System) modeling framework. We first present proof-of-concept but non-trivial results from a simplistic coupling scheme. We then report progress towards augmenting SNAC with a Basic Model Interface (BMI), a framework-agnostic standard interface developed by CSDMS that uses the CSDMS Standard Names as controlled vocabulary for model communication across domains. Newly interfaced to BMI, SNAC will be easily coupled with CHILD as well as other BMI-compatible models. In broader context, this work will test BMI as a general and easy-to-implement mechanism for sharing models between modeling frameworks and is a part of the NSF-funded EarthCube Building Blocks project, "Earth System Bridge: Spanning Scientific Communities with Interoperable Modeling Frameworks."

  15. Double resonance surface enhanced Raman scattering substrates: an intuitive coupled oscillator model.

    PubMed

    Chu, Yizhuo; Wang, Dongxing; Zhu, Wenqi; Crozier, Kenneth B

    2011-08-01

    The strong coupling between localized surface plasmons and surface plasmon polaritons in a double resonance surface enhanced Raman scattering (SERS) substrate is described by a classical coupled oscillator model. The effects of the particle density, the particle size and the SiO2 spacer thickness on the coupling strength are experimentally investigated. We demonstrate that by tuning the geometrical parameters of the double resonance substrate, we can readily control the resonance frequencies and tailor the SERS enhancement spectrum. PMID:21934853

  16. Development of an unstructured-grid wave-current coupled model and its application

    NASA Astrophysics Data System (ADS)

    Feng, Xingru; Yin, Baoshu; Yang, Dezhou

    2016-08-01

    An unstructured grid wave-current coupled model was developed by coupling the SWAN (Simulating Waves Nearshore) wave model and ADCIRC (Advanced Circulation model) ocean model through the Model Coupling Toolkit (MCT). The developed coupled model has high spatial resolution in the coastal area and is efficient for computation. The efficiency of the newly developed SWAN + ADCIRC model was compared with that of the widely-used SWAN + ADCIRC coupled model, in which SWAN and ADCIRC are coupled directly rather than through the MCT. Results show that the directly-coupled model is more efficient when the total number of computational cores is small, but the MCT-coupled model begin to run faster than the directly-coupled model when more computational cores are used. The MCT-coupled model maintains the scalability longer and can increase the simulation efficiency more than 35% by comparing the minimum wall clock time of one day simulation in the test runs. The MCT-coupled SWAN + ADCIRC model was used to simulate the storm surge and waves during the typhoon Usagi which formed in the western Pacific on September 17, 2013 and landed at Shanwei, China. Three numerical experiments were performed to investigate the effect of wave-current interaction on the storm surge and waves. The results show that the coupled model can better simulate the storm surge and waves when considering the wave-induced radiation stress, the wave effect on the wind stress drag coefficient and the modulation of current and water level on waves. During the typhoon Usagi, the effect of wave radiation stress could result in a maximum of 0.75 m increase in the extreme storm surge, and the wave induced wind stress could cause a -0.82∼0.48 m change of the extreme storm surge near the coastal area. Besides, the radiation stress forced currents cannot be ignored either in the study of mass transport at coastal zones. Results of this study are useful for understanding the wave-current interaction processes and

  17. An interacting dark energy model with nonminimal derivative coupling

    NASA Astrophysics Data System (ADS)

    Nozari, Kourosh; Behrouz, Noushin

    2016-09-01

    We study cosmological dynamics of an extended gravitational theory that gravity is coupled non-minimally with derivatives of a dark energy component and there is also a phenomenological interaction between the dark energy and dark matter. Depending on the direction of energy flow between the dark sectors, the phenomenological interaction gets two different signs. We show that this feature affects the existence of attractor solution, the rate of growth of perturbations and stability of the solutions. By considering an exponential potential as a self-interaction potential of the scalar field, we obtain accelerated scaling solutions that are attractors and have the potential to alleviate the coincidence problem. While in the absence of the nonminimal derivative coupling there is no attractor solution for phantom field when energy transfers from dark matter to dark energy, we show an attractor solution exists if one considers an explicit nonminimal derivative coupling for phantom field in this case of energy transfer. We treat the cosmological perturbations in this setup with details to show that with phenomenological interaction, perturbations can grow faster than the minimal case.

  18. Communicating Science to Impact Learning? A Phenomenological Inquiry into 4th and 5th Graders' Perceptions of Science Information Sources

    NASA Astrophysics Data System (ADS)

    Gelmez Burakgazi, Sevinc; Yildirim, Ali; Weeth Feinstein, Noah

    2016-04-01

    Rooted in science education and science communication studies, this study examines 4th and 5th grade students' perceptions of science information sources (SIS) and their use in communicating science to students. It combines situated learning theory with uses and gratifications theory in a qualitative phenomenological analysis. Data were gathered through classroom observations and interviews in four Turkish elementary schools. Focus group interviews with 47 students and individual interviews with 17 teachers and 10 parents were conducted. Participants identified a wide range of SIS, including TV, magazines, newspapers, internet, peers, teachers, families, science centers/museums, science exhibitions, textbooks, science books, and science camps. Students reported using various SIS in school-based and non-school contexts to satisfy their cognitive, affective, personal, and social integrative needs. SIS were used for science courses, homework/project assignments, examination/test preparations, and individual science-related research. Students assessed SIS in terms of the perceived accessibility of the sources, the quality of the content, and the content presentation. In particular, some sources such as teachers, families, TV, science magazines, textbooks, and science centers/museums ("directive sources") predictably led students to other sources such as teachers, families, internet, and science books ("directed sources"). A small number of sources crossed context boundaries, being useful in both school and out. Results shed light on the connection between science education and science communication in terms of promoting science learning.

  19. Clinical development of new prophylactic antimalarial drugs after the 5th Amendment to the Declaration of Helsinki

    PubMed Central

    Dow, Geoffrey S; Magill, Alan J; Ohrt, Colin

    2008-01-01

    Malaria is of continuing concern in nonimmune traveling populations. Traditionally, antimalarial drugs have been developed as agents for dual indications (treatment and prophylaxis). However, since 2000, when the 5th Amendment to the Declaration of Helsinki (DH2000) was adopted, development of new malaria prophylaxis drugs in this manner has ceased. As a consequence, there may not be any new drugs licensed for this indication in the foreseeable future. Major pharmaceutical companies have interpreted DH2000 to mean that the traditional development paradigm may be considered unethical because of doubt over the likelihood of benefit to endemic populations participating in clinical studies, the use of placebo, and the sustainability of post-trial access to study medications. In this article, we explore the basis of these concerns and suggest that the traditional development paradigm remains ethical under certain circumstances. We also consider alternative approaches that may be more attractive to sponsors as they either do not use placebo, or utilize populations in endemic countries who may unambiguously benefit. These approaches represent the way forward in the future, but are at present unproven in clinical practice, and face numerous regulatory, logistical and technical challenges. Consequently, in the short term, we argue that the traditional clinical development paradigm remains the most feasible approach and is ethical and consistent with the spirit of DH2000 under the appropriate circumstances. PMID:19209263

  20. Attitudes towards General Practice: a comparative cross-sectional survey of 1st and 5th year medical students

    PubMed Central

    Kruschinski, Carsten; Wiese, Birgitt; Hummers-Pradier, Eva

    2012-01-01

    Objective: Positive attitudes towards General Practice can be understood as a prerequisite for becoming a General Practitioner (GP) and for collaboration with GPs later on. This study aimed to assess attitudes of medical students at the beginning and the end of medical school. Methods: A total of 160 1st year students at Hannover Medical School were surveyed. Their attitudes were compared to those of 287 5th year students. Descriptive, bi- and multivariate analyses were performed to investigate influences of year of study and gender. Results: Year of study and gender both were associated with the attitudes towards General Practice. The interest in General Practice and patient-orientation (communication, care of older patients with chronic diseases) was higher in 1st year students compared to more advanced students. Female students valued such requirements more than male students, the differences in attitudes between the years of study being more pronounced in male students. Conclusion: Despite some limitations caused by the cross-sectional design, the attitudes towards General Practice competencies changed to their disadvantage during medical school. This suggests a formative influence of the strategies used in medical education. Educational strategies, however, could be used to bring about a change of attitudes in the other direction. PMID:23255966

  1. Bond Strength of 5th, 6th and 7th Generation Bonding Agents to Intracanal Dentin of Primary Teeth

    PubMed Central

    Afshar, Hossein; Baradaran Nakhjavani, Yahya; Rahro Taban, Sedighe; Baniameri, Zahra; Nahvi, Azam

    2015-01-01

    Objectives: This in-vitro study sought to assess the push-out bond strength of a total etch and 2 self-etch bonding systems to intracanal dentin of primary anterior teeth (PAT). Materials and Methods: Thirty-six primary anterior teeth were randomly divided into 3 groups of 5th generation (Single Bond 2), 6th generation (Clearfil SE) and 7th generation (Single Bond Universal) bonding agents. The canal orifice was restored with composite resin and the push-out test was carried out to assess the bond strength. After applying the push-out load, specimens were evaluated under a light microscope at 40X magnification. One-way ANOVA and log-rank test on Kaplan-Meier curves were applied for the comparison of bond strength among the 3 groups. Results: The mean± standard deviation (SD) bond strength was 13.6±5.33 MPa for Single Bond 2, 13.85±5.86 MPa for Clearfil SE and 12.28±5.24 MPa for Single Bond Universal. The differences in bond strength among the 3 groups were not statistically significant (P>0.05). Conclusion: All three bonding agents are recommended for use with composite posts in PAT. However, due to high technical sensitivity of the Total Etch system, single or two-step self etch systems may be preferred for uncooperative children. PMID:26056518

  2. Final Report for DOE Support of 5th the International Workshop on Oxide Surfaces (IWOX-V)

    SciTech Connect

    Charles T. Campbell

    2007-02-02

    The 5th International Workshop on Oxide Surfaces (IWOX-V) was held at Granlibakken Conference center in Lake Tahoe, CA, January 7-12. The total attendance was ~90. The breakdown of attendees by country is as follows: USA 41 Germany 18 Japan 7 UK 5 Italy 5 France 4 Austria 3 Denmark 3 Cech. Repub. 1 Ireland 1 New Zealand 1 India 1 The technical program included oral sessions on the electronic and magnetic properties of oxide surfaces, surface and interface structure, advances in theory, surface defects, thin film oxides on metals and on oxides, thin film metals on oxides, surface photochemistry, surface reactivity, and interactions with water. Two evening poster sessions had similar themes. As in previous years, the program stimulated significant interest and discussion among the attendees. The local expenses (food and lodging, $918 per person) for eight foreign invited speakers were covered by BES funds. In addition, partial reimbursement for travel ($328 per person) was supported by BES funds for two more foreign invited speakers.

  3. Coupled Dynamic Modeling of Floating Wind Turbine Systems: Preprint

    SciTech Connect

    Wayman, E. N.; Sclavounos, P. D.; Butterfield, S.; Jonkman, J.; Musial, W.

    2006-03-01

    This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts

  4. Modelling the Effects of Electrical Coupling between Unmyelinated Axons of Brainstem Neurons Controlling Rhythmic Activity.

    PubMed

    Hull, Michael J; Soffe, Stephen R; Willshaw, David J; Roberts, Alan

    2015-05-01

    Gap junctions between fine unmyelinated axons can electrically couple groups of brain neurons to synchronise firing and contribute to rhythmic activity. To explore the distribution and significance of electrical coupling, we modelled a well analysed, small population of brainstem neurons which drive swimming in young frog tadpoles. A passive network of 30 multicompartmental neurons with unmyelinated axons was used to infer that: axon-axon gap junctions close to the soma gave the best match to experimentally measured coupling coefficients; axon diameter had a strong influence on coupling; most neurons were coupled indirectly via the axons of other neurons. When active channels were added, gap junctions could make action potential propagation along the thin axons unreliable. Increased sodium and decreased potassium channel densities in the initial axon segment improved action potential propagation. Modelling suggested that the single spike firing to step current injection observed in whole-cell recordings is not a cellular property but a dynamic consequence of shunting resulting from electrical coupling. Without electrical coupling, firing of the population during depolarising current was unsynchronised; with coupling, the population showed synchronous recruitment and rhythmic firing. When activated instead by increasing levels of modelled sensory pathway input, the population without electrical coupling was recruited incrementally to unpatterned activity. However, when coupled, the population was recruited all-or-none at threshold into a rhythmic swimming pattern: the tadpole "decided" to swim. Modelling emphasises uncertainties about fine unmyelinated axon physiology but, when informed by biological data, makes general predictions about gap junctions: locations close to the soma; relatively small numbers; many indirect connections between neurons; cause of action potential propagation failure in fine axons; misleading alteration of intrinsic firing properties

  5. An energy-conserving one-way coupled mode propagation model.

    PubMed

    Abawi, Ahmad T

    2002-01-01

    The equations of motion for pressure and displacement fields in a waveguide have been used to derive an energy-conserving, one-way coupled mode propagation model. This model has three important properties: First, since it is based on the equations of motion, rather than the wave equation, instead of two coupling matrices, it only contains one coupling matrix. Second, the resulting coupling matrix is anti-symmetric, which implies that the energy among modes is conserved. Third, the coupling matrix can be computed using the local modes and their depth derivatives. The model has been applied to two range-dependent cases: Propagation in a wedge, where range dependence is due to variations in water depth and propagation through internal waves, where range dependence is due to variations in water sound speed. In both cases the solutions are compared with those obtained from the parabolic equation (PE) method. PMID:11831790

  6. Synchronization Experiments With A Global Coupled Model of Intermediate Complexity

    NASA Astrophysics Data System (ADS)

    Selten, Frank; Hiemstra, Paul; Shen, Mao-Lin

    2013-04-01

    In the super modeling approach an ensemble of imperfect models are connected through nudging terms that nudge the solution of each model to the solution of all other models in the ensemble. The goal is to obtain a synchronized state through a proper choice of connection strengths that closely tracks the trajectory of the true system. For the super modeling approach to be successful, the connections should be dense and strong enough for synchronization to occur. In this study we analyze the behavior of an ensemble of connected global atmosphere-ocean models of intermediate complexity. All atmosphere models are connected to the same ocean model through the surface fluxes of heat, water and momentum, the ocean is integrated using weighted averaged surface fluxes. In particular we analyze the degree of synchronization between the atmosphere models and the characteristics of the ensemble mean solution. The results are interpreted using a low order atmosphere-ocean toy model.

  7. Wind waves modelling on the water body with coupled WRF and WAVEWATCH III models

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Alexandra; Troitskaya, Yuliya; Kandaurov, Alexander; Baydakov, Georgy; Vdovin, Maxim; Papko, Vladislav; Sergeev, Daniil

    2015-04-01

    Simulation of ocean and sea waves is an accepted instrument for the improvement of the weather forecasts. Wave modelling, coupled models modelling is applied to open seas [1] and is less developed for moderate and small inland water reservoirs and lakes, though being of considerable interest for inland navigation. Our goal is to tune the WAVEWATCH III model to the conditions of the inland reservoir and to carry out the simulations of surface wind waves with coupled WRF (Weather Research and Forecasting) and WAVEWATCH III models. Gorky Reservoir, an artificial lake in the central part of the Volga River formed by a hydroelectric dam, was considered as an example of inland reservoir. Comparing to [2] where moderate constant winds (u10 is up to 9 m/s) of different directions blowing steadily all over the surface of the reservoir were considered, here we apply atmospheric model WRF to get wind input to WAVEWATCH III. WRF computations were held on the Yellowstone supercomputer for 4 nested domains with minimum scale of 1 km. WAVEWATCH III model was tuned for the conditions of the Gorky Reservoir. Satellite topographic data on altitudes ranged from 56,6° N to 57,5° N and from 42.9° E to 43.5° E with increments 0,00833 ° in both directions was used. 31 frequencies ranged from 0,2 Hz to 4 Hz and 30 directions were considered. The minimal significant wave height was changed to the lower one. The waves in the model were developing from some initial seeding spectral distribution (Gaussian in frequency and space, cosine in direction). The range of the observed significant wave height in the numerical experiment was from less than 1 cm up to 30 cm. The field experiments were carried out in the south part of the Gorky reservoir from the boat [2, 3]. 1-D spectra of the field experiment were compared with those obtained in the numerical experiments with different parameterizations of flux provided in WAVEWATCH III both with constant wind input and WRF wind input. For all the

  8. Diagnosing coupled watershed processes using a fully-coupled groundwater, land-surface, surface water and mesoscale atmospheric model

    NASA Astrophysics Data System (ADS)

    Maxwell, R. M.; Kollet, S. J.; Chow, F. K.

    2007-12-01

    A variably-saturated groundwater flow model with an integrated overland flow component, a land-surface model and a mesoscale atmospheric model is used to examine the interplay between coupled water and energy processes. These processes are influenced by land-surface topography and subsurface heterogeneity. This parallel, integrated model simulates spatial variations in land-surface forcing driven by three-dimensional (3D) atmospheric and subsurface components. Spatial statistics are used to demonstrate spatial and temporal correlations between surface and lower atmospheric variables and water table depth. These correlations are particularly strong during times when the land surface temperatures trigger shifts in wind behavior, such as during early morning surface heating. Additionally, spectral transforms of subsurface arrival times are computed using a transient Lagrangian transport simulation. Macrodispersion is used to mimic the effects of subsurface heterogeneity for a range of Peclet numbers. The slopes of these transforms indicate fractal scaling of this system over a range of timescales. All of these techniques point to importance of realistically representing coupled processes and the need to understand and diagnose these processes in nature. This work was conducted under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory (LLNL) under contract W-7405-Eng-48. This project was funded by the Laboratory Directed Research and Development Program at LLNL

  9. Tightly wrapped semiconductor-axon microtubes for probing hybrid networks: Modeling the capacitive coupling strength

    NASA Astrophysics Data System (ADS)

    Diedrich, Daniel; Blick, Robert H.

    2015-02-01

    We present finite-element simulations modeling the electromagnetic interaction between axons and semiconductor microtubes. These tubes are tightly wrapped around the axons, enabling highly efficient capacitive coupling. The calculations reveal that the capacitive coupling strength is in the pA regime.

  10. Revised Interseismic Coupling Models for the North Island, New Zealand, Using FEM-Derived Green's Functions

    NASA Astrophysics Data System (ADS)

    Williams, C. A.; Wallace, L. M.

    2015-12-01

    The Hikurangi subduction margin adjacent to the North Island, New Zealand, displays a variation in interseismic coupling behavior along strike, with shallow coupling in the north and deeper coupling in the south (Wallace et al., 2012). With new information such as an improved interface geometry, a New Zealand-wide seismic velocity model and an increased density and duration of geodetic networks, it is now possible to provide a much more detailed picture of interseismic coupling at the Hikurangi margin than in previous studies. In previous work (Williams and Wallace, 2015), we examined the effects of material property variations on slip estimates for slow slip events (SSEs) along the Hikurangi margin, and found that in cases where the slip is deep or there is good geodetic coverage above the slipping region, heterogeneous models generally predict about 20% less slip than elastic half-space models. Based on those results, we anticipate that interseismic coupling models that account for elastic heterogeneity will also predict similarly lower slip deficit rates in such regions. To explore these ideas, we are developing a new interseismic coupling model for the North Island. We use a New Zealand-wide seismic velocity model (Eberhart-Phillips et al., 2010) to provide elastic properties and an improved Hikurangi interface geometry (Williams et al., 2013) as the basis for our subduction geometry. In addition to the Hikurangi subduction interface, we generate finite element meshes for 20 additional faults that compose the North Island portion of the elastic block model of Wallace et al. (2012). We generate Green's functions for all faults using the PyLith finite element code (Aagaard et al., 2013), and then use the Defnode geodetic inversion code (McCaffrey, 1995; 2002) to invert for block rotation poles and interseismic coupling. Our revised coupling model should provide better constraints on interseismic coupling in the North Island, and should thus provide a better

  11. A multiscale coupling method for the modeling of dynamics of solids with application to brittle cracks

    SciTech Connect

    Li Xiantao Yang, Jerry Z. E, Weinan

    2010-05-20

    We present a multiscale model for numerical simulations of dynamics of crystalline solids. The method combines the continuum nonlinear elasto-dynamics model, which models the stress waves and physical loading conditions, and molecular dynamics model, which provides the nonlinear constitutive relation and resolves the atomic structures near local defects. The coupling of the two models is achieved based on a general framework for multiscale modeling - the heterogeneous multiscale method (HMM). We derive an explicit coupling condition at the atomistic/continuum interface. Application to the dynamics of brittle cracks under various loading conditions is presented as test examples.

  12. Report of the proceedings of the Colloquium and Workshop on Multiscale Coupled Modeling

    NASA Technical Reports Server (NTRS)

    Koch, Steven E. (Editor)

    1993-01-01

    The Colloquium and Workshop on Multiscale Coupled Modeling was held for the purpose of addressing modeling issues of importance to planning for the Cooperative Multiscale Experiment (CME). The colloquium presentations attempted to assess the current ability of numerical models to accurately simulate the development and evolution of mesoscale cloud and precipitation systems and their cycling of water substance, energy, and trace species. The primary purpose of the workshop was to make specific recommendations for the improvement of mesoscale models prior to the CME, their coupling with cloud, cumulus ensemble, hydrology, air chemistry models, and the observational requirements to initialize and verify these models.

  13. Modeling and temperature regulation of a thermally coupled reactor system via internal model control strategy

    SciTech Connect

    Lee, S.Y.; Coronella, C.J.; Bhadkamkar, A.S.; Seader, J.D.

    1993-12-01

    A two-stage, thermally coupled fluidized-bed reactor system has been developed for energy-efficient conversion of tar-sand bitumen to synthetic crude oil. Modeling and temperature control of a system are addressed in this study. A process model and transfer function are determined by a transient response technique and the reactor temperature are controlled by PI controllers with tuning settings determined by an internal model control (IMC) strategy. Using the IMC tuning method, sufficiently good control performance was experimentally observed without lengthy on-line tuning. It is shown that IMC strategy provides a means to directly use process knowledge to make a control decision. Although this control method allows for fine tuning by adjusting a single tuning parameter, it is not easy to determine the optimal value of this tuning parameter, which must be specified by the user. A novel method is presented to evaluate that parameter, which must be specified by the user. A novel method is presented to evaluate that parameter in this study. It was selected based on the magnitude of elements on the off-diagonal of the relative gain array to account for the effect of thermal coupling on control performance. It is shown that this method provides stable and fast control of reactor temperatures. By successfully decoupling the system, a simple method of extending the IMC tuning technique to multiinput/multioutput systems is obtained.

  14. On the coupling between fluid flow and mesh motion in the modelling of fluid structure interaction

    NASA Astrophysics Data System (ADS)

    Dettmer, Wulf G.; Perić, Djordje

    2008-12-01

    Partitioned Newton type solution strategies for the strongly coupled system of equations arising in the computational modelling of fluid solid interaction require the evaluation of various coupling terms. An essential part of all ALE type solution strategies is the fluid mesh motion. In this paper, we investigate the effect of the terms which couple the fluid flow with the fluid mesh motion on the convergence behaviour of the overall solution procedure. We show that the computational efficiency of the simulation of many fluid solid interaction processes, including fluid flow through flexible pipes, can be increased significantly if some of these coupling terms are calculated exactly.

  15. Non-minimal coupling in Higgs–Yukawa model with asymptotically safe gravity

    NASA Astrophysics Data System (ADS)

    Oda, Kin-ya; Yamada, Masatoshi

    2016-06-01

    We study the fixed-point structure of the Higgs–Yukawa model, with its scalar being non-minimally coupled to the asymptotically safe gravity, using the functional renormalization group. We have obtained the renormalization group equations for the cosmological and Newton constants, the scalar mass squared and quartic coupling constant, and the Yukawa and non-minimal coupling constants, taking into account all the scalar, fermion, and graviton loops. We find that switching on the fermionic quantum fluctuations makes the non-minimal coupling constant irrelevant around the Gaussian-matter fixed point with asymptotically safe gravity.

  16. The Thirring interaction in the two-dimensional axial-current-pseudoscalar derivative coupling model

    SciTech Connect

    Belvedere, L.V. . E-mail: armflavio@if.uff.br

    2006-12-15

    We reexamine the two-dimensional model of massive fermions interacting with a massless pseudoscalar field via axial-current derivative coupling. The hidden Thirring interaction in the axial-derivative coupling model is exhibited compactly by performing a canonical field transformation on the Bose field algebra and the model is mapped into the Thirring model with an additional vector-current-scalar derivative interaction (Schroer-Thirring model). The Fermi field operator is rewritten in terms of the Mandelstam soliton operator coupled to a free massless scalar field. The charge sectors of the axial-derivative model are mapped into the charge sectors of the massive Thirring model. The complete bosonized version of the model is presented. The bosonized composite operators of the quantum Hamiltonian are obtained as the leading operators in the Wilson short distance expansions.

  17. Simulation of seasonal anomalies of atmospheric circulation using coupled atmosphere-ocean model

    NASA Astrophysics Data System (ADS)

    Tolstykh, M. A.; Diansky, N. A.; Gusev, A. V.; Kiktev, D. B.

    2014-03-01

    A coupled atmosphere-ocean model intended for the simulation of coupled circulation at time scales up to a season is developed. The semi-Lagrangian atmospheric general circulation model of the Hydrometeorological Centre of Russia, SLAV, is coupled with the sigma model of ocean general circulation developed at the Institute of Numerical Mathematics, Russian Academy of Sciences (INM RAS), INMOM. Using this coupled model, numerical experiments on ensemble modeling of the atmosphere and ocean circulation for up to 4 months are carried out using real initial data for all seasons of an annual cycle in 1989-2010. Results of these experiments are compared to the results of the SLAV model with the simple evolution of the sea surface temperature. A comparative analysis of seasonally averaged anomalies of atmospheric circulation shows prospects in applying the coupled model for forecasts. It is shown with the example of the El Niño phenomenon of 1997-1998 that the coupled model forecasts the seasonally averaged anomalies for the period of the nonstationary El Niño phase significantly better.

  18. Atmosphere - Sea Ice Coupling in the Navy's Global Coupled Modeling System: Diagnosing Polar Prediction using the sea ice models, CICE4 and CICE5, coupled with the NAVGEM Atmospheric Model.

    NASA Astrophysics Data System (ADS)

    Barton, N. P.; Chen, J.; Whitcomb, T.

    2015-12-01

    The United States Naval Research Laboratory is developing a global coupled model for sub-seasonal to seasonal predictions under the Earth System Prediction Capability national program. The Navy's full Earth System coupled model has a dynamic atmosphere, ocean, and sea ice. This presentation only examines atmosphere - sea ice coupling without using a dynamic ocean to isolate interactions. The Navy's Global Environmental Model (NAVGEM) is used for the atmospheric model and two versions of the Los Alamos National Laboratory's Community sea ICe Code (CICE version 4 and 5) are used for sea ice model. Data assimilative five day hindcasts are performed from March 2014 to September 2014 using NAVGEM-CICE4 and NAVGEM-CICE5 configurations. Differences in sea ice and low-level temperatures are examined in detail. The NAVGEM-CICE5 configuration results in a larger coverage of sea ice compared to the NAVGEM-CICE4 configuration, and this is consistent with thicker sea ice in the NAVGEM-CICE5 runs. Low-level temperatures in the NAVGEM-CICE4 are greater during Northern Hemisphere spring compared to the NAVGEM-CICE5 configuration. NAVGEM-CICE5 has larger albedos compared to the NAVGEM-CICE4 configuration and may be a primary cause in the lower low-level temperatures. Lastly, these results are discussed in relation to the stand-alone NAVGEM.

  19. Progress and Challenges in Coupled Hydrodynamic-Ecological Estuarine Modeling

    EPA Science Inventory

    Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational po...

  20. Using a Coupled Lake Model with WRF for Dynamical Downscaling

    EPA Science Inventory

    The Weather Research and Forecasting (WRF) model is used to downscale a coarse reanalysis (National Centers for Environmental Prediction–Department of Energy Atmospheric Model Intercomparison Project reanalysis, hereafter R2) as a proxy for a global climate model (GCM) to examine...

  1. Model of bound interface dynamics for coupled magnetic domain walls

    NASA Astrophysics Data System (ADS)

    Politi, P.; Metaxas, P. J.; Jamet, J.-P.; Stamps, R. L.; Ferré, J.

    2011-08-01

    A domain wall in a ferromagnetic system will move under the action of an external magnetic field. Ultrathin Co layers sandwiched between Pt have been shown to be a suitable experimental realization of a weakly disordered 2D medium in which to study the dynamics of 1D interfaces (magnetic domain walls). The behavior of these systems is encapsulated in the velocity-field response v(H) of the domain walls. In a recent paper [P. J. Metaxas , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.104.237206 104, 237206 (2010)] we studied the effect of ferromagnetic coupling between two such ultrathin layers, each exhibiting different v(H) characteristics. The main result was the existence of bound states over finite-width field ranges, wherein walls in the two layers moved together at the same speed. Here we discuss in detail the theory of domain wall dynamics in coupled systems. In particular, we show that a bound creep state is expected for vanishing H and we give the analytical, parameter free expression for its velocity which agrees well with experimental results.

  2. Simulating High Flux Isotope Reactor Core Thermal-Hydraulics via Interdimensional Model Coupling

    SciTech Connect

    Travis, Adam R

    2014-05-01

    A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a twodimensional slice oriented perpendicular to the fuel plate s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

  3. Comparison of a coupled atmosphere-ocean (WRF-ROMS) model with an atmosphere only model (WRF) of two North Atlantic hurricanes

    NASA Astrophysics Data System (ADS)

    Mooney, P.; Mulligan, F. J.; Bruyere, C. L.; Bonnlander, B.

    2013-12-01

    We investigate the ability of a coupled regional atmosphere-ocean modeling system to simulate two extreme events in the North Atlantic. In this study we use the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST; Warner et al., 2010) modeling system with only the atmosphere and ocean models activated. COAWST couples the atmosphere model (Weather Research and Forecasting model; WRF) to the ocean model (Regional Ocean Modeling System; ROMS) with the Model Coupling Toolkit. Results from the coupled system are compared with atmosphere only simulations of North Atlantic storms to evaluate the performance of the coupled modeling system. Two extreme events (Hurricane Katia and Hurricane Irene) were chosen to assess the level of improvement (or otherwise) arising from coupling WRF with ROMS. These two hurricanes involve different dynamics and present different challenges to the modeling system. Modelled storm tracks, storm intensities and sea surface temperatures are compared with observations to appraise the coupled modeling system's simulation of these two extreme events.

  4. An ice-ocean coupled model for the Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    Cheng, Abe; Preller, Ruth

    1992-01-01

    The Hibler ice model has been modified and adapted to a domain that includes most of the sea ice-covered areas in the Northern Hemisphere. This model, joined with the Cox ocean model, is developed as an enhancement to the U.S. Navy's sea ice forecasting, PIPS, and is termed PIPS2.0. Generally, the modeled ice edge is consistent with the Navy-NOAA Joint Ice Center weekly analysis, and the modeled ice thickness distribution agrees with submarine sonar data in the central Arctic basin.

  5. Coupled fvGCM-GCE Modeling System, 3D Cloud-Resolving Model and Cloud Library

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2005-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud-resolving models (CRMs) agree with observations better than traditional singlecolumn models in simulating various types of clouds and cloud systems from Merent geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloudscale model (termed a super-parameterization or multiscale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameteridon NASA satellite and field campaign cloud related datasets can provide initial conditions as well as validation for both the MMF and CRMs. A seed fund is available at NASA Goddard to build a MMF based on the 2D Goddard cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM). A prototype MMF in being developed and production nms will be conducted at the beginning of 2005. In this talk, I will present: (1) A brief review on GCE model and its applications on precipitation processes, (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), (3) A cloud library generated by Goddard MMF, and 3D GCE model, and (4) A brief discussion on the GCE model on developing a global cloud simulator.

  6. Coupled fvGCM-GCE Modeling System, 3D Cloud-Resolving Model and Cloud Library

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2005-01-01

    Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that cloud- resolving models (CRMs) agree with observations better than traditional single-column models in simulating various types of clouds and cloud systems from different geographic locations. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a super-parameterization or multi-scale modeling framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign cloud related datasets can provide initial conditions as well as validation for both the MMF and CRMs. A seed fund is available at NASA Goddard to build a MMF based on the 2D Goddard Cumulus Ensemble (GCE) model and the Goddard finite volume general circulation model (fvGCM). A prototype MMF in being developed and production runs will be conducted at the beginning of 2005. In this talk, I will present: (1) A brief review on GCE model and its applications on precipitation processes, ( 2 ) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), (3) A cloud library generated by Goddard MMF, and 3D GCE model, and (4) A brief discussion on the GCE model on developing a global cloud simulator.

  7. PCB modeling in the Gulf of Lions using a 3D coupled model

    NASA Astrophysics Data System (ADS)

    Alekseenko, Elena; Thouvenin, Bénédicte; Tixier, Céline; Tronczynski, Jacek; Garreau, Pierre; Verney, Romaric; Carlotti, Francois; Espinasse, Boris; Queguiner, Bernard; Baklouti, Melika

    2013-04-01

    Polychlorobiphenyls (PCBs) are synthetic chlorinated organic compounds, which were widely used in many industrial materials. These compounds are persistent, bioaccumulable and toxic for living organisms. The riverine and atmospheric fluxes are the major routes of entry for these chemicals into marine ecosystems, where they are now embedded in natural biogeochemical cycles (Lohmann et al. 2007). Because of bioaccumulation and biomagnification processes in food webs, even nowadays, these compounds may attain dangerous concentration levels especially in the top predators including marine mammals. The contamination of marine biota by PCBs in Mediterranean has also become a matter of concern as the concentrations in some species are at levels putting them at risk for significant biological effects. This may pose potential human health risks in commercial edible species (Carpenter 2006). Planktonic populations play a key role in the trophic food webs in marine ecosystems by the mobilisation and transfer of energy and organic matter towards higher trophic levels. This work aims at a better understanding of the role of plankton in the transfer of PCBs to higher trophic levels in the Gulf of Lions (Mediterranean) by coupling of biogeochemical, ecological and hydrodynamical processes. Modeling is a powerful tool for coupling processes of different disciplines and scales. The recent development of 3D hydrodynamic, hydrosedimentary and biogeochemical models in the Mediterranean (André et al, 2005,2009, Ulses et al, 2008, Dufois et al, 2008, Auger et al, 2011), enables feasibility testing of coupling these models with transfer processes of chemical contaminants. The lack of detailed observations in the sea and the significant uncertainty on contaminants inputs prevent from a proper validation of such modeling tests. However, these tools are very useful to assess the influence of fast processes on the transfer of contaminants to bioaccumulative species. Sensitivity analysis

  8. Coupled edge-core model of fusion reactor

    NASA Astrophysics Data System (ADS)

    Zagórski, R.; Kulinski, S.; Scholz, M.

    1997-10-01

    A model has been developed which is capable to describe in a self consistent way the plasma dynamics in the centre and edge region of a fusion reactor. The core plasma is treated in the frame of the 0D model in which an empirical scaling law for the energy confinement time is included. The model accounts for energy losses due to Bremsstrahlung and line radiation as well as alpha particle heating. A 1D analytical model for plasma and impurity transport outside the last close magnetic surface (LCMS) is applied. The model accounts for the strong gradients of the plasma parameters along the magnetic field lines in the divertor. The sputtering phenomena at the plate and radiating cooling by injected impurities are treated self consistently in the model. The model has been used to investigate operating regimes of the ignition experiment. Analysis have been performed for different first wall materials (C, Ni, Mo, W) for ITER like tokamak.

  9. A coupled dynamical-radiational model of stratocumulus

    NASA Astrophysics Data System (ADS)

    Ye, Weizuo

    1990-05-01

    A model dealing with interactions between the air and low stratiform clouds is presented based on the mixed-layer model Lilly (1968) pioneered and on Deardorff's three dimensional numerical model results. Its main new aspects lie in 1) consideration of the natures of both the atmosphere and cloud; 2) a new entrainment velocity scheme with few arbitrary assumptions; 3) transition from one-mixed layer to two-mixed layer model; and 4) parameterization of radiation and precipitation calculations. The model results for radiation, moisture, and heat turbulent fluxes turn out to be in good agreement with those calculated or observed by Kawa (1988), Nicholls (1984), and Schmets et al. (1981) in California, the North Sea, and the North Atlantic, respectively. Basically, this paper furnishes the theoretical basis for a model to address questions concerning the time-evolution of thermodynamical profiles both in cloud and out of cloud. The applications of this model wil be in a separate paper.

  10. MASSIVELY PARALLEL FULLY COUPLED IMPLICIT MODELING OF COUPLED THERMAL-HYDROLOGICAL-MECHANICAL PROCESSES FOR ENHANCED GEOTHERMAL SYSTEM RESERVOIRS

    SciTech Connect

    Robert Podgorney; Hai Huang; Derek Gaston

    2010-02-01

    Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing) to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid system and our ability to reliably predict how reservoirs behave under stimulation and production. In order to increase our understanding of how reservoirs behave under these conditions, we have developed a physics-based rock deformation and fracture propagation simulator by coupling a discrete element model (DEM) for fracturing with a continuum multiphase flow and heat transport model. In DEM simulations, solid rock is represented by a network of discrete elements (often referred as particles) connected by various types of mechanical bonds such as springs, elastic beams or bonds that have more complex properties (such as stress-dependent elastic constants). Fracturing is represented explicitly as broken bonds (microcracks), which form and coalesce into macroscopic fractures when external load is applied. DEM models have been applied to a very wide range of fracturing processes from the molecular scale (where thermal fluctuations play an important role) to scales on the order of 1 km or greater. In this approach, the continuum flow and heat transport equations are solved on an underlying fixed finite element grid with evolving porosity and permeability for each grid cell that depends on the local structure of the discrete element network (such as DEM particle density). The fluid pressure gradient exerts forces on individual elements of the DEM network, which therefore deforms and

  11. A Coupled Finite-Volume Model for 2-D Surface and 3-D Subsurface Flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface-subsurface interactions are an intrinsic component of the hydrologic response within a watershed; therefore, hydrologic modeling tools should consider these interactions to provide reliable predictions, especially during rainfall-runoff processes. This paper presents a fully implicit coupled...

  12. Use of Data to Improve Seasonal-to-Interannual Forecasts Simulated by Intermediate Coupled Models

    NASA Technical Reports Server (NTRS)

    Perigaud, C.; Cassou, C.; Dewitte, B.; Fu, L-L.; Neelin, J.

    1999-01-01

    This paper provides a detailed illustration that it can be much more beneficial for ENSO forecasting to use data to improve the model parameterizations rather than to modify the initial conditions to gain in consistency with the simulated coupled system.

  13. When should orthostatic blood pressure changes be evaluated in elderly: 1st, 3rd or 5th minute?

    PubMed

    Soysal, Pinar; Aydin, Ali Ekrem; Koc Okudur, Saadet; Isik, Ahmet Turan

    2016-01-01

    Detection of orthostatic hypotension (OH) is very important in geriatric practice, since OH is associated with mortality, ischemic stroke, falls, cognitive failure and depression. It was aimed to determine the most appropriate time for measuring blood pressure in transition from supine to upright position in order to diagnose OH in elderly. Comprehensive geriatric assessment (CGA) including Head up Tilt Table (HUT) test was performed in 407 geriatric patients. Orthostatic changes were assessed separately for the 1st, 3rd and 5th minutes (HUT1, HUT3 and HUT5, respectively) taking the data in supine position as the basis. The mean age, recurrent falls, presence of dementia and Parkinson's disease, number of drugs, alpha-blocker and anti-dementia drug use, and fasting blood glucose levels were significantly higher in the patients with versus without OH; whereas, albumin and 25-hydroxy vitamin D levels were significantly lower (p<0.05). However, different from HUT3 and HUT5, Charlson Comorbidity Index and the prevalence of diabetes mellitus were higher, the use of antidiabetics, antipsychotics, benzodiazepine, opioid and levodopa were more common (p<0.05). Statistical significance of the number of drugs and fasting blood glucose level was prominent in HUT1 as compared to HUT3 (p<0.01, p<0.05). Comparison of the patients that had OH only in HUT1, HUT3or HUT5 revealed no difference in terms of CGA parameters. These results suggests that orthostatic blood pressure changes determined at the 1st minute might be more important for geriatric practice. Moreover, 1st minute measurement might be more convenient in the elderly as it requires shorter time in practice. PMID:27077324

  14. Intraocular tissue ablation using an optical fibre to deliver the 5th harmonic of a Nd:YAG

    NASA Astrophysics Data System (ADS)

    Miller, Joseph; Yu, Xiaobo; Yu, Paula K.; Cringle, Stephen J.; Yu, Dao-Yi

    2009-02-01

    We report the evaluation of a system which delivers the 5th harmonic of an Nd:YAG (213nm) via optical fibre to ocular tissue sites. The 213nm beam is concentrated, using a hollow glass taper, prior to launch into 200 μm or 600 μm core diameter silica/silica optical fibre. The fibre tip was tapered to enhance the fluence delivered. An operating window of fluence values that could be delivered via 330 - 1100mm lengths of optical fibre was determined. The lower value of 0.2J/cm2 determined by the ablation threshold of the tissue and the upper value of 1.3J/cm2 by the launch, transmission and tip characteristics of the optical fibre. The fluence output decreased as a function of both transmitted pulse energy and number of pulses transmitted. Fresh retinal tissue was cleanly ablated with minimal damage to the surrounding tissue. Lesions were generated using 1, 3 and 10 pulses with fluences from 0.2 to 1.0J/cm2. The lesion depth demonstrated clear dose dependence. Lesions generated in ex vivo preparations of human trabecular meshwork in a fluid environment also demonstrated dose dependence, 50 pulses being sufficient to create a hole within the trabecular meshwork extending to Schlemm's canal. The dose dependence of the ablation depth combined with the ability of this technique to create a conduit through to Schlemm's canal demonstrates the potential of this technique for ophthalmological applications requiring precise and controlled intraocular tissue removal and has potential applications in the treatment and management of glaucoma.

  15. Ignition calculations using a reduced coupled-mode electron- ion energy exchange model*

    NASA Astrophysics Data System (ADS)

    Garbett, W. J.; Chapman, D. A.

    2016-03-01

    Coupled-mode models for electron-ion energy exchange can predict large deviations from standard binary collision models in some regimes. A recently developed reduced coupled-mode model for electron-ion energy exchange, which accurately reproduces full numerical results over a wide range of density and temperature space, has been implemented in the Nym hydrocode and used to assess the impact on ICF capsule fuel assembly and performance. Simulations show a lack of sensitivity to the model, consistent with results from a range of simpler alternative models. Since the coupled-mode model is conceptually distinct to models based on binary collision theory, this result provides increased confidence that uncertainty in electron-ion energy exchange will not impact ignition attempts.

  16. Two-Dimensional Coupled Distributed Hydrologic-Hydraulic Model Simulation on Watershed

    NASA Astrophysics Data System (ADS)

    Cea, Miguel; Rodriguez, Martin

    2016-03-01

    The objective of this work is to develop a coupled distributed model that enables to analyze water movement in watershed as well as analyze the rainfall-runoff. More specifically, it allows to estimate the various hydrologic water cycle variables at each point of the watershed. In this paper, we have carried out a coupled model of a distributed hydrological and two-dimensional hydraulic models. We have incorporated a hydrological rainfall-runoff model calculated by cell based on the Soil Conservation Service (SCS) method to the hydraulic model, leaving it for the hydraulic model (GUAD2D) to conduct the transmission to downstream cells. The goal of the work is demonstrate the improved predictive capability of the coupled Hydrological-Hydraulic models in a watershed.

  17. Field experiment and Modeling full coupling hydrologic model with mircotopography in typical watershed

    NASA Astrophysics Data System (ADS)

    Xiang, Long; Zhu, Yongshu; Xu, Ruchao; Yu, Zhongbo; Chen, Li

    2015-04-01

    With high human activties and landscape remodeling, the various landuse and micropography are newly added in scienctific sight. In order to quanify the solpo effect in high resolution sub-grid system, three-dimensional Richards' equations and the two-dimensional diffusion wave equations are chosen to solve the output difference between hydro-flows, The difficulty of quantitating surface water and groundwater interaction and parameterizing the microtopography with the help of multi-scale observation experiments. For three-dimensional coupling mechanism in surface-subsurface system, we design real-time observations on water flow at Hydrologic Response Units (HRU) located on various landuse and outlet in Meilin experimental watershed. The continuously observed data disclose the principle of runoff yield spatially and temporally, and show the surface runoff redistribution, unsaturated soil water dynamics, shallow groundwater response to typical rainfall-runoff events on complex microtopographic slope. A surface storage function with elevation various is embeded into diffuse wave equations to describe microtopographic effect. we improve for paramterizing microtopography in subelements and evaluate the strength of microtopography and couple length at soil-water interface impacting the hydrologic modeling. Based on observed conclusions, a full physical based distributed model system is established at Meilin watershed to quantify the hydrodynamic processes of overland flow, soil water saturation, and groundwater level and analyze dynamic exchanges among them in simulation. The relationships between the various saturation area (VSA) and runoff yield and flow confluence in each typical event are quantified statistically. With the field work and simulations, we demostrated the approach to describe complex hydrologic processes in human-interrupted watershed. Keywords: micropography, coupling mechanism, various saturation area, surface storage

  18. Heinrich events modeled with a coupled complex ice sheet-climate model

    NASA Astrophysics Data System (ADS)

    Ziemen, Florian; Rodehacke, Christian; Mikolajewicz Mikolajewicz, Uwe

    2013-04-01

    We investigate glacial climate variability with a coupled ice sheet model (ISM) - atmosphere-ocean-vegetation general circulation model (AOVGCM) system, focusing on one of the most prominent features of glacial climate variability, the Heinrich events. Modeling past climates and periods of past climate change is an important test of the capability of climate models to correctly represent future climate changes. Only if we can correctly represent past climates and climate changes, we can be confident about our predictions of future climate changes. We show results from two experiments: (1) a steady-state LGM experiment where the ice sheet model is accelerated by a factor of 10 compared to the climate model covering 30 kyrs in the ISM (3 kyrs in the AOVGCM) and (2) a synchronously coupled experiment focusing in on one ice sheet collapse covering 3.2 kyrs in both models. For the experiments, we coupled a modified version of the Parallel Ice Sheet Model (mPISM) bidirectionally with the AOVGCM ECHAM5/MPIOM/LPJ. ECHAM5 and LPJ were run in T31 resolution (~ 3.75°), MPIOM on a grid with a nominal resolution of 3° and poles over Greenland and Antarctica, mPISM on a 20 km grid covering most of the northern hemisphere. In the models, as well as in the coupling, no flux correction or anomaly maps are applied. The ice sheet surface mass balance is computed using a positive degree day scheme with lapse rate correction and height desertification effect. In the experiments, the surges of the Hudson Strait Ice Stream reach discharge rates of 60000 m3/s and show a typical recurrence interval of 7 kyrs, matching the basic characteristics for Heinrich events inferred from proxy data. The surges are consequences of an internal instability mechanism suggested by MacAyeal (1993) and various parts of the ice sheets show repeated surging. The large ice discharge during a surge of the Hudson Strait Ice Stream causes an expansion of the sea ice cover in the Labrador Sea and the adjacent

  19. Modelling surface water flood risk using coupled numerical and physical modelling techniques

    NASA Astrophysics Data System (ADS)

    Green, D. L.; Pattison, I.; Yu, D.

    2015-12-01

    Surface water (pluvial) flooding occurs due to intense precipitation events where rainfall cannot infiltrate into the sub-surface or drain via storm water systems. The perceived risk appears to have increased in recent years with pluvial flood events seeming more severe and frequent within the UK. Surface water flood risk currently accounts for one third of all UK flood risk, with approximately two million people living in urban areas being at risk of a 1 in 200 year flood event. Surface water flooding research often focuses upon using 1D, 2D or 1D-2D coupled numerical modelling techniques to understand the extent, depth and severity of actual or hypothetical flood scenarios. Although much research has been conducted using numerical modelling, field data available for model calibration and validation is limited due to the complexities associated with data collection in surface water flood conditions. Ultimately, the data which numerical models are based upon is often erroneous and inconclusive. Physical models offer an alternative and innovative environment to collect data within. A controlled, closed system allows independent variables to be altered individually to investigate cause and effect relationships. Despite this, physical modelling approaches are seldom used in surface water flooding research. Scaled laboratory experiments using a 9m2, two-tiered physical model consisting of: (i) a mist nozzle type rainfall simulator able to simulate a range of rainfall intensities similar to those observed within the United Kingdom, and; (ii) a fully interchangeable, scaled plot surface have been conducted to investigate and quantify the influence of factors such as slope, impermeability, building density/configuration and storm dynamics on overland flow and rainfall-runoff patterns within a range of terrestrial surface conditions. Results obtained within the physical modelling environment will be compared with numerical modelling results using FloodMap (Yu & Lane, 2006

  20. Coupled cluster Green function: Model involving single and double excitations

    NASA Astrophysics Data System (ADS)

    Bhaskaran-Nair, Kiran; Kowalski, Karol; Shelton, William A.

    2016-04-01

    In this paper, we report on the development of a parallel implementation of the coupled-cluster (CC) Green function formulation (GFCC) employing single and double excitations in the cluster operator (GFCCSD). A key aspect of this work is the determination of the frequency dependent self-energy, Σ(ω). The detailed description of the underlying algorithm is provided, including approximations used that preserve the pole structure of the full GFCCSD method, thereby reducing the computational costs while maintaining an accurate character of methodology. Furthermore, for systems with strong local correlation, our formulation reveals a diagonally dominate block structure where as the non-local correlation increases, the block size increases proportionally. To demonstrate the accuracy of our approach, several examples including calculations of ionization potentials for benchmark systems are presented and compared against experiment.

  1. Coupled cluster Green function: Model involving single and double excitations.

    PubMed

    Bhaskaran-Nair, Kiran; Kowalski, Karol; Shelton, William A

    2016-04-14

    In this paper, we report on the development of a parallel implementation of the coupled-cluster (CC) Green function formulation (GFCC) employing single and double excitations in the cluster operator (GFCCSD). A key aspect of this work is the determination of the frequency dependent self-energy, Σ(ω). The detailed description of the underlying algorithm is provided, including approximations used that preserve the pole structure of the full GFCCSD method, thereby reducing the computational costs while maintaining an accurate character of methodology. Furthermore, for systems with strong local correlation, our formulation reveals a diagonally dominate block structure where as the non-local correlation increases, the block size increases proportionally. To demonstrate the accuracy of our approach, several examples including calculations of ionization potentials for benchmark systems are presented and compared against experiment. PMID:27083702

  2. Development of a coupled thermo-hydro-mechanical model in discontinuous media for carbon sequestration

    SciTech Connect

    Fang, Yilin; Nguyen, Ba Nghiep; Carroll, Kenneth C.; Xu, Zhijie; Yabusaki, Steven B.; Scheibe, Timothy D.; Bonneville, Alain

    2013-06-22

    Geomechanical alteration of porous media is generally ignored for most shallow subsurface applications, whereas CO2 injection, migration, and trapping in deep saline aquifers will be controlled by coupled multifluid flow, energy transfer, and geomechanical processes. The accurate assessment of the risks associated with potential leakage of injected CO2 and the design of effective injection systems requires that we represent these coupled processes within numerical simulators. The objectives of this study were to develop a coupled thermal-hydro-mechanical model into a single software, and to examine the coupling of thermal, hydrological, and geomechanical processes for simulation of CO2 injection into the subsurface for carbon sequestration. A numerical model is developed to couple nonisothermal multiphase hydrological and geomechanical processes for prediction of multiple interconnected processes for carbon sequestration in deep saline aquifers. The geomechanics model was based on Rigid Body-Spring Model (RBSM), one of the discrete methods to model discontinuous rock system. Poisson’s effect that was often ignored by RBSM was considered in the model. The simulation of large-scale and long-term coupled processes in carbon capture and storage projects requires large memory and computational performance. Global Array Toolkit was used to build the model to permit the high performance simulations of the coupled processes. The model was used to simulate a case study with several scenarios to demonstrate the impacts of considering coupled processes and Poisson’s effect for the prediction of CO2 sequestration.

  3. Spinors on a curved noncommutative space: coupling to torsion and the Gross-Neveu model

    NASA Astrophysics Data System (ADS)

    Burić, Maja; Madore, John; Nenadović, Luka

    2015-09-01

    We analyse the Dirac action on the truncated Heisenberg algebra and in particular, the nonminimal couplings to the background gravitational field. By projection to the Heisenberg algebra we obtain a renormalisable model: the noncommutative extension of the Gross-Neveu model. This result indicates that, as on the commutative curved backgrounds, nonminimal couplings with torsion and curvature are necessary (and sufficient) for renormalisability of scalar and spinor theories on the curved noncommutative spaces.

  4. Mathematical modeling of intrinsic Josephson junctions with capacitive and inductive couplings

    NASA Astrophysics Data System (ADS)

    Rahmonov, I. R.; Shukrinov, Yu M.; Zemlyanaya, E. V.; Sarhadov, I.; Andreeva, O.

    2012-11-01

    We investigate the current voltage characteristics (CVC) of intrinsic Josephson junctions (IJJ) with two types of couplings between junctions: capacitive and inductive. The IJJ model is described by a system of coupled sine-Gordon equations which is solved numerically by the 4th order Runge-Kutta method. The method of numerical simulation and numerical results are presented. The magnetic field distribution is calculated as the function of coordinate and time at different values of the bias current. The influence of model parameters on the CVC is studied. The behavior of the IJJ in dependence on coupling parameters is discussed.

  5. Vertically integrated models for coupled two-phase flow and geomechanics in porous media

    NASA Astrophysics Data System (ADS)

    Bjørnarâ, Tore I.; Nordbotten, Jan M.; Park, Joonsang

    2016-02-01

    Models of reduced dimensionality have been found to be particularly attractive in simulating the fate of injected CO2 in supercritical state in the context of carbon capture and storage. This is motivated by the confluence of three aspects: the strong buoyant segregation of the lighter CO2 phase above water, the relatively long time scales associated with storage, and finally the large aspect ratios that characterize the geometry of typical storage aquifers. However, to date, these models have been confined to considering only the flow problem, as the coupling between reduced dimensionality models for flow and models for geomechanical response has previously not been developed. Herein, we develop a fully coupled, reduced dimension, model for multiphase flow and geomechanics. It is characterized by the aquifer(s) being of lower dimension(s), while the surrounding overburden and underburden being of full dimension. The model allows for general constitutive functions for fluid flow (relative permeability and capillary pressure) and uses the standard Biot coupling between the flow and mechanical equations. The coupled model retains all the simplicities of reduced-dimensional models for flow, including less stiff nonlinear systems of equations (since the upscaled constitutive functions are closer to linear), longer time steps (since the high grid resolution in the vertical direction can be avoided), and less degrees of freedom. We illustrate the applicability of the new coupled model through both a validation study and a practical computational example.

  6. An electromechanical coupling model of a bending vibration type piezoelectric ultrasonic transducer.

    PubMed

    Zhang, Qiang; Shi, Shengjun; Chen, Weishan

    2016-03-01

    An electromechanical coupling model of a bending vibration type piezoelectric ultrasonic transducer is proposed. The transducer is a Langevin type transducer which is composed of an exponential horn, four groups of PZT ceramics and a back beam. The exponential horn can focus the vibration energy, and can enlarge vibration amplitude and velocity efficiently. A bending vibration model of the transducer is first constructed, and subsequently an electromechanical coupling model is constructed based on the vibration model. In order to obtain the most suitable excitation position of the PZT ceramics, the effective electromechanical coupling coefficient is optimized by means of the quadratic interpolation method. When the effective electromechanical coupling coefficient reaches the peak value of 42.59%, the optimal excitation position (L1=22.52 mm) is found. The FEM method and the experimental method are used to validate the developed analytical model. Two groups of the FEM model (the Group A center bolt is not considered, and but the Group B center bolt is considered) are constructed and separately compared with the analytical model and the experimental model. Four prototype transducers around the peak value are fabricated and tested to validate the analytical model. A scanning laser Doppler vibrometer is employed to test the bending vibration shape and resonance frequency. Finally, the electromechanical coupling coefficient is tested indirectly through an impedance analyzer. Comparisons of the analytical results, FEM results and experiment results are presented, and the results show good agreement. PMID:26705603

  7. Coupled wave-ocean modeling system experiments in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Clementi, Emanuela; Oddo, Paolo; Korres, Gerasimos; Pinardi, Nadia; Drudi, Massimiliano; Tonani, Marina; Grandi, Alessandro; Adani, Mario

    2015-04-01

    Wind waves and oceanic circulation processes are of major interest in determining accurate sea state predictions and their interactions are very important for individual dynamic processes. This work presents a coupled wave-current numerical modelling system composed by the ocean circulation model NEMO (Nucleus for European Modelling of the Ocean) and the third generation wave model WaveWatchIII (WW3) implemented in the Mediterranean Sea with 1/16° horizontal resolution and forced by ECMWF atmospheric fields. In order to evaluate the performance of the coupled model, two sets of numerical experiments have been performed and described in this work. A first set of experiments has been built by coupling the wave and circulation models that hourly exchange the following fields: the sea surface currents and air-sea temperature difference are transferred from NEMO model to WW3 model modifying respectively the mean momentum transfer of waves and the wind speed stability parameter; while the neutral drag coefficient computed by WW3 model is passed to NEMO that computes the turbulent component. Five years (2009-2013) numerical experiments have been carried out in both uncoupled and coupled modes. In order to validate the modelling system, numerical results have been compared with coastal and drifting buoys and remote sensing data. Comparison results demonstrate that the WW3 model can fairly reproduce the observed wave characteristics and show that the wave-current interactions improve the representation of the wave spectrum. Minor improvements have been reached by comparing coupled and uncoupled circulation NEMO model results with observations. A second set of numerical experiments has been performed by considering NEMO model one-way coupled with WW3 model. The hydrodynamic model receives from the wave model the neutral drag coefficient and a set of wave fields used to calculate the wave-induced vertical mixing according to Qiao et al. (2010) formulation. Two experiments

  8. An integrated hydrologic modeling framework for coupling SWAT with MODFLOW

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Soil and Water Assessment Tool (SWAT), MODFLOW, and Energy Balance based Evapotranspiration (EB_ET) models are extensively used to estimate different components of the hydrological cycle. Surface and subsurface hydrological processes are modeled in SWAT but limited to the extent of shallow aquif...

  9. A zonally averaged, coupled ocean-atmosphere model for paleoclimate studies

    SciTech Connect

    Stocker, T.F.; Mysak, L.A. ); Wright, D.G. )

    1992-08-01

    A zonally averaged ocean model for the thermohaline circulation is coupled to a zonally averaged, one-layer energy balance model of the atmosphere to form a climate model for paleoclimate studies. The emphasis of the coupled model is on the ocean's thermohaline circulation in the Pacific, Atlantic, and Indian oceans. Under present-day conditions, the global conveyor belt is simulated. Latitude-depth structures of modeled temperature and salinity fields, as well as depth-integrated meridional transports of heat and freshwater, compare well with estimates from observations when wind stress is included. Ekman cells are present in the upper ocean and contribute substantially to the meridional fluxes at low latitudes.The atmospheric component of the coupled climate model consists of a classical balance model. When the two components are coupled after being spun up individually, the system remains steady. If intermittent convection is operating, the coupled model shows systematic deviations of the surface salinity, which may result in reversals of the thermohaline circulation. This climate drift can be inhibited by removing intermittent convection prior to coupling. The climate model is applied to investigate the effect of excess freshwater discharge into the North Atlantic, and the influence of the parameterization of precipitation is tested. The Atlantic thermohalinc flow is sensitive to anomalous freshwater input. Reversals of the deep circulation can occur in the Atlantic, leading to a state where deep water is formed only in the Southern Ocean. A feedback mechanism is identified that may also trigger the reversal of the Pacific thermobaline circulation yielding the inverse conveyor bell as an additional steady state. In total, four different stable equilibria of the coupled model were realized.

  10. A Coupled Vegetation-Crust Model for Patchy Landscapes

    NASA Astrophysics Data System (ADS)

    Kinast, Shai; Ashkenazy, Yosef; Meron, Ehud

    2016-03-01

    A new model for patchy landscapes in drylands is introduced. The model captures the dynamics of biogenic soil crusts and their mutual interactions with vegetation growth. The model is used to identify spatially uniform and spatially periodic solutions that represent different vegetation-crust states, and map them along the rainfall gradient. The results are consistent extensions of the vegetation states found in earlier models. A significant difference between the current and earlier models of patchy landscapes is found in the bistability range of vegetated and unvegetated states; the incorporation of crust dynamics shifts the onset of vegetation patterns to a higher precipitation value and increases the biomass amplitude. These results can shed new light on the involvement of biogenic crusts in desertification processes that involve vegetation loss.

  11. Comparison of vibration dissociation coupling and radiative heat transfer models for AOTV/AFE flowfields

    NASA Technical Reports Server (NTRS)

    Carlson, Leland A.; Bobskill, Glenn J.; Greendyke, Robert B.

    1988-01-01

    A series of detailed studies comparing various vibration dissociation coupling models, reaction systems and rates, and radiative heating models has been conducted for the nonequilibrium stagnation region of an AFE/AOTV vehicle. Atomic and molecular nonequilibrium radiation correction factors have been developed and applied to various absorption coefficient step models, and a modified vibration dissociation coupling model has been shown to yield good vibration/electronic temperature and concentration profiles. While results indicate sensitivity to the choice of vibration dissociation coupling model and to the nitrogen electron impact ionization rate, by proper combinations accurate flowfield and radiative heating results can be obtained. These results indicate that nonequilibrium effects significantly affect the flowfield and the radiative heat transfer. However, additional work is needed in ionization chemistry and absorption coefficient modeling.

  12. Modeling Coupled Evaporation and Seepage in Ventilated Cavities

    SciTech Connect

    T. Ghezzehei; R. Trautz; S. Finsterle; P. Cook; C. Ahlers

    2004-07-01

    Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small.

  13. Analysis of coupling errors in a physically-based integrated surface water-groundwater model

    NASA Astrophysics Data System (ADS)

    Dagès, Cécile; Paniconi, Claudio; Sulis, Mauro

    2012-12-01

    Several physically-based models that couple 1D or 2D surface and 3D subsurface flow have recently been developed, but few studies have evaluated the errors directly associated with the different coupling schemes. In this paper we analyze the causes of mass balance error for a conventional and a modified sequential coupling scheme in worst-case scenario simulations of Hortonian runoff generation on a sloping plane catchment. The conventional scheme is noniterative, whereas for the modified scheme the surface-subsurface exchange fluxes are determined via a boundary condition switching procedure that is performed iteratively during resolution of the nonlinear subsurface flow equation. It is shown that the modified scheme generates much lower coupling mass balance errors than the conventional sequential scheme. While both coupling schemes are sensitive to time discretization, the iterative control of infiltration in the modified scheme greatly limits its sensitivity to temporal resolution. Little sensitivity to spatial discretization is observed for both schemes. For the modified scheme the different factors contributing to coupling error are isolated, and the error is observed to be highly correlated to the flood recession duration. More testing, under broader hydrologic contexts and including other coupling schemes, is recommended so that the findings from this first analysis of coupling errors can be extended to other surface water-groundwater models.

  14. Modeling the effect of glacier recession on streamflow response using a coupled glacio-hydrological model

    SciTech Connect

    Naz, Bibi S; Frans, Chris; Clarke, Garry; Burns,; Lettenmaier, Dennis

    2014-01-01

    We describe an integrated spatially distributed hydrologic and glacier dynamic model, and use it to investigate the effect of glacier recession on streamflow variations for the Upper Bow River basin, a tributary of the South Saskatchewan River. Several recent studies have suggested that observed decreases in summer flows in the South Saskatchewan River are partly due to the retreat of glaciers in the river's headwaters. Modeling the effect of glacier changes on streamflow response in river basins such as the South Saskatchewan is complicated due to the inability of most existing physically-based distributed hydrologic models to represent glacier dynamics. We compare predicted variations in glacier extent, snow water equivalent and streamflow discharge made with the integrated model with satellite estimates of glacier area and terminus position, observed streamflow and snow water equivalent measurements over the period of 1980 2007. Simulations with the coupled hydrology-glacier model reduce the uncertainty in streamflow predictions. Our results suggested that on average, the glacier melt contribution to the Bow River flow upstream of Lake Louise is about 30% in summer. For warm and dry years, however, the glacier melt contribution can be as large as 50% in August, whereas for cold years, it can be as small as 20% and the timing of glacier melt signature can be delayed by a month.

  15. Coupling of an individual-based model of anchovy with lower trophic level and hydrodynamic models

    NASA Astrophysics Data System (ADS)

    Wang, Yuheng; Wei, Hao; Kishi, Michio J.

    2013-03-01

    Anchovy ( Engraulis japonicus), a small pelagic fish and food of other economic fishes, is a key species in the Yellow Sea ecosystem. Understanding the mechanisms of its recruitment and biomass variation is important for the prediction and management of fishery resources. Coupled with a hydrodynamic model (POM) and a lower trophic level ecosystem model (NEMURO), an individual-based model of anchovy is developed to study the influence of physical environment on anchovy's biomass variation. Seasonal variations of circulation, water temperature and mix-layer depth from POM are used as external forcing for NEMURO and the anchovy model. Biomasses of large zooplankton and predatory zooplankton which anchovy feeds on are output from NEMURO and are controlled by the consumption of anchovy on them. Survival fitness theory related to temperature and food is used to determine the swimming action of anchovy in the model. The simulation results agree well with observations and elucidate the influence of temperature in over-wintering migration and food in feeding migration.

  16. Mixed boundary conditions versus coupling with an energy-moisture balance model for a zonally averaged ocean climate model

    SciTech Connect

    Bjornsson, H.; Mysak, L.A.; Schmidt, G.A.

    1997-10-01

    The Wright and Stocker oceanic thermohaline circulation model is coupled to a recently developed zonally averaged energy moisture balance model for the atmosphere. The results obtained with this coupled model are compared with those from an ocean-only model that employs mixed boundary conditions. The ocean model geometry uses either one zonally averaged interhemispheric basin (the {open_quotes}Atlantic{close_quotes}) or two zonally averaged basins (roughly approximating the Atlantic and the Pacific Oceans) connected by a parameterized Antarctic Circumpolar Current. The differences in the steady states and their linear stability are examined over a wide range of parameters. The presence of additional feedbacks between the ocean circulation and the atmosphere and hydrological cycle in the coupled model produces significant differences between the latter and the ocean-only model, in both the one-basin and two-basin geometries. The authors conclude that due to the effects produced by the feedbacks in the coupled model, they must have serious reservations about the results concerning long-term climate variability obtained from ocean-only models. Thus, to investigate long-term climatic variability a coupled model is necessary. 31 refs., 15 figs., 7 tabs.

  17. A Mathematical Model Coupling Tumor Growth and Angiogenesis

    PubMed Central

    Gomez, Hector

    2016-01-01

    We present a mathematical model for vascular tumor growth. We use phase fields to model cellular growth and reaction-diffusion equations for the dynamics of angiogenic factors and nutrients. The model naturally predicts the shift from avascular to vascular growth at realistic scales. Our computations indicate that the negative regulation of the Delta-like ligand 4 signaling pathway slows down tumor growth by producing a larger density of non-functional capillaries. Our results show good quantitative agreement with experiments. PMID:26891163

  18. Coupled two-dimensional edge plasma and neutral gas modeling of tokamak scrape-off-layers

    SciTech Connect

    Maingi, R.

    1992-08-01

    The objective of this study is to devise a detailed description of the tokamak scrape-off-layer (SOL), which includes the best available models of both the plasma and neutral species and the strong coupling between the two in many SOL regimes. A good estimate of both particle flux and heat flux profiles at the limiter/divertor target plates is desired. Peak heat flux is one of the limiting factors in determining the survival probability of plasma-facing-components at high power levels. Plate particle flux affects the neutral flux to the pump, which determines the particle exhaust rate. A technique which couples a two-dimensional (2-D) plasma and a 2-D neutral transport code has been developed (coupled code technique), but this procedure requires large amounts of computer time. Relevant physics has been added to an existing two-neutral-species model which takes the SOL plasma/neutral coupling into account in a simple manner (molecular physics model), and this model is compared with the coupled code technique mentioned above. The molecular physics model is benchmarked against experimental data from a divertor tokamak (DIII-D), and a similar model (single-species model) is benchmarked against data from a pump-limiter tokamak (Tore Supra). The models are then used to examine two key issues: free-streaming-limits (ion energy conduction and momentum flux) and the effects of the non-orthogonal geometry of magnetic flux surfaces and target plates on edge plasma parameter profiles.

  19. Indian Health Career Handbook and Report on Ned Hatathli Seminar for Southern Arizona Indian Students (5th, Tucson, Arizona, February 6-7, 1975).

    ERIC Educational Resources Information Center

    Taylor, Arnold, Ed.; And Others

    Utilizing comments from teachers, professionals, college and high school students, this report is derived from the 5th Ned Hatathli Seminar, sponsored by the Navajo Health Authority, and presents factual information relative to American Indian participation in Indian Health careers. The following major speeches are presented: (1) "The Practice of…

  20. Engaging Minds. Proceedings of the National Academy for Integration of Research, Teaching and Learning Annual Conference (5th, Galway, Ireland, June 9-10, 2011)

    ERIC Educational Resources Information Center

    National Academy for Integration of Research, Teaching and Learning (NJ1), 2011

    2011-01-01

    This publication contains the papers presented at the 5th Annual Conference of National Academy for Integration of Research, Teaching and Learning (NAIRTL) and the 9th Galway Symposium. Presenters from across Ireland and overseas share their perspectives. The theme of engagement touches on the very heart of what a "higher" education should be…

  1. Immediate and Short-Term Effects of the 5th Grade Version of the "keepin' it REAL" Substance Use Prevention Intervention

    ERIC Educational Resources Information Center

    Hecht, Michael L.; Elek, Elvira; Wagstaff, David A.; Kam, Jennifer A.; Marsiglia, Flavio; Dustman, Patricia; Reeves, Leslie; Harthun, Mary

    2009-01-01

    This study assessed the immediate and short-term outcomes of adapting a culturally-grounded middle school program, "keepin' it REAL", for elementary school students. After curriculum adaptation, 10 schools were randomly assigned to the intervention in 5th grade with follow-up boosters in 6th grade; 13 schools were randomly assigned to the control…

  2. International Roundtable on The Lifelong Learning and New Technologies Gap: Reaching the Disadvantaged (5th, Philadelphia, Pennsylvania, December 8-10, 1999). Preliminary Report.

    ERIC Educational Resources Information Center

    National Center on Adult Literacy, Philadelphia, PA.

    Three elements defined the focus of the 5th Roundtable: lifelong learning, the new technologies gap, and reaching the disadvantaged. Participants referred frequently to the digital divide, a term that captures differential access to and use of information and communication technology (ICT). The questions that guided discussion related to ICT and…

  3. Evaluation of the Effects of Argumentation Based Science Teaching on 5th Grade Students' Conceptual Understanding of the Subjects Related to "Matter and Change"

    ERIC Educational Resources Information Center

    Çinar, Derya; Bayraktar, Sule

    2014-01-01

    The aim of this study is to evaluate the effects of Argumentation Based Science Teaching on 5th grade students' conceptual understanding of the subjects related to "Matter and Change". This research is a qualitative research and its design is a multiple (compare) case study. In this study, semi-structured interviews related to the…

  4. Evaluation of the Effects of Argumentation Based Science Teaching on 5th Grade Students' Conceptual Understanding of the Subjects Related to "Matter and Change"

    ERIC Educational Resources Information Center

    Çinar, Derya; Bayraktar, Sule

    2014-01-01

    The aim of this study is to evaluate the effects of Argumentation Based Science Teaching on 5th grade students' conceptual understanding of the subjects related to "Matter and Change". This research is a qualitative research and its design is a multiple (compare) case study. In this study, semi-structured interviews related to the…

  5. Measures of self-efficacy and norms for low-fat milk consumption are reliable and related to beverage consumption among 5th graders at school lunch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to determine the reliability and validity of scales measuring low-fat milk consumption self-efficacy and norms during school lunch among a cohort of 5th graders. Two hundred seventy-five students completed lunch food records and a psychosocial questionnaire measuring self-efficacy ...

  6. The Effect of Direct Instruction Strategy on Math Achievement of Primary 4th and 5th Grade Students with Learning Difficulties

    ERIC Educational Resources Information Center

    Al-Makahleh, Ahmad Abdulhameed Aufan

    2011-01-01

    This study seeks to verify the effect of direct instruction strategy on Math achievment of students with learning difficulties in the fourth and fifth grade levels and measure the improvement in their attitudes to Mathematics. Sample consisted of sixty (60) students with Math learning difficulties attending 4th and 5th grade level resource rooms…

  7. Color Duplex Assessment of 4th and 5th Internal Mammary Artery Perforators: The Pedicles of the Medially Based Lower Pole Breast Flaps

    PubMed Central

    Abdel-Monem, Kareem; Elshahat, Ahmed; Abou-Gamrah, Sherif; Eldin Abol-Atta, Hossam; Abd Eltawab, Reda; Massoud, Karim

    2012-01-01

    Objective: Reconstruction of a breast after mastectomy using the contralateral lower pole breast flap is an appealing procedure because it uses the tissues that were going to be excised during reduction of the sound breast to achieve symmetry. Literature mentioned that these flaps are supplied by the lower internal mammary artery perforators (IMAPs) with no further details. The aim of this study was to determine the site, size, and number of the 4th and 5th IMAPs by using preoperative color Duplex ultrasound and intraoperative exploration. Method: Twenty breasts in 10 patients who presented for reduction mammoplasty were included in this study. Preoperative color duplex was used to determine IMAPs in the 4th and 5th intercostal spaces. These perforators were localized intraoperatively. Intravenous fluorescein injection was used to determine the perfusion of the lower pole breast flap on the basis of these perforators. Results: Statistically, the 4th IMAPs diameters were significantly larger than the 5th IMAPs diameters (P < .05). The lower pole breast flap was perfused through these perforators. Conclusion: Color Duplex ultrasound is an accurate tool to preoperatively determine the 4th and 5th IMAPs. PMID:22292100

  8. Final technical report: Partial support for US participants in the 5th International Marine Biotechnology Conference, Townsville, Australia, Sept 29 - Oct 5, 2000

    SciTech Connect

    Zohar, Yonathan; Hill, R.; Robb, F.

    2001-04-09

    Funding was provided for US participants in the 5th International Marine Biotechnology Conference held in Townsville, Australia from September 29 to October 5, 2000. DOE funds were used for travel awards for six US participants in this conference. DOE funds were successfully used to advance participation of US scientists in the important emerging field of marine biotechnology.

  9. An Analysis of the Learning Activities Covered in the 5th Grade Science Textbooks Based on 2005 and 2013 Turkish Science Curricula

    ERIC Educational Resources Information Center

    Aydogdu, Cemil; Idin, Sahin

    2015-01-01

    The aim of this study is to analyze the learning activities covered in 5th grade elementary science textbooks which depend on 2005 and 2013 elementary science curricula. Two elementary science textbooks [which] depend on 2005 science curriculum and two elementary science textbooks [which] depend on 2013 science curriculum were researched. The…

  10. An Analysis of the Learning Activities Covered in the 5th Grade Science Textbooks Based on 2005 and 2013 Turkish Science Curricula

    ERIC Educational Resources Information Center

    Aydogdu, Cemil; Idin, Sahin

    2015-01-01

    The aim of this study is to analyze the learning activities covered in 5th grade elementary science textbooks which depend on 2005 and 2013 elementary science curricula. Two elementary science textbooks depends on 2005 science curriculum and two elementary science textbooks depend on 2013 science curriculum were researched. The study is a…

  11. The Social Interactions of Students with Disabilities in a 5th Grade Level Inclusive Classroom and the Effect on Academic Achievement

    ERIC Educational Resources Information Center

    Marshall-Reed, Estella

    2010-01-01

    This dissertation is a qualitative, ethnographic case study of 3 students with disabilities. The purpose of this research study was to observe and collect descriptive accounts of the social interactions that exist between the cultures in a 5th grade level inclusive classroom, such as the interactions between the special education students, general…

  12. Comparison of the Leiter International Performance Scale-Revised and the Stanford-Binet Intelligence Scales, 5th Edition, in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Grondhuis, Sabrina Nicole; Mulick, James A.

    2013-01-01

    A review of hospital records was conducted for children evaluated for autism spectrum disorders who completed both the Leiter International Performance Scale-Revised (Leiter-R) and Stanford-Binet Intelligence Scales, 5th Edition (SB5). Participants were between 3 and 12 years of age. Diagnoses were autistic disorder (n = 26, 55%) and pervasive…

  13. U.S. Dietary and Physical Activity Guideline Knowledge and Corresponding Behaviors among 4th and 5th Grade Students: A Multi-Site Pilot Study

    ERIC Educational Resources Information Center

    Bea, Jennifer W.; Martinez, Stephanie; Armstrong-Florian, Traci; Farrell, Vanessa; Martinez, Cathy; Whitmer, Evelyn; Hartz, Vern; Blake, Samuel; Nicolini, Ariana; Misner, Scottie

    2014-01-01

    Knowledge of U.S. dietary and physical activity recommendations and corresponding behaviors were surveyed among 4th and 5th graders in five Arizona counties to determine the need for related education in SNAP-Ed eligible schools. A <70% target response rate was the criterion. Participants correctly identified recommendations for: fruit, 20%;…

  14. EUNIS '99: Information Technology Shaping European Universities. Proceedings of the International European University Information Systems (5th, Espoo, Finland, June 7-9, 1999).

    ERIC Educational Resources Information Center

    1999

    This document presents the proceedings from the 5th International European University Information Systems (EUNIS) Conference on Information Technology that took place in Helsinki, Finland on June 7-9, 1999. Topics of the conference proceedings were divided into five tracks (A through E): Use of Information Technology in Learning and Teaching;…

  15. Mathematical modeling of gap junction coupling and electrical activity in human β-cells

    NASA Astrophysics Data System (ADS)

    Loppini, Alessandro; Braun, Matthias; Filippi, Simonetta; Gram Pedersen, Morten

    2015-12-01

    Coordinated insulin secretion is controlled by electrical coupling of pancreatic β-cells due to connexin-36 gap junctions. Gap junction coupling not only synchronizes the heterogeneous β-cell population, but can also modify the electrical behavior of the cells. These phenomena have been widely studied with mathematical models based on data from mouse β-cells. However, it is now known that human β-cell electrophysiology shows important differences to its rodent counterpart, and although human pancreatic islets express connexin-36 and show evidence of β-cell coupling, these aspects have been little investigated in human β-cells. Here we investigate theoretically, the gap junction coupling strength required for synchronizing electrical activity in a small cluster of cells simulated with a recent mathematical model of human β-cell electrophysiology. We find a lower limit for the coupling strength of approximately 20 pS (i.e., normalized to cell size, ˜2 pS pF-1) below which spiking electrical activity is asynchronous. To confront this theoretical lower bound with data, we use our model to estimate from an experimental patch clamp recording that the coupling strength is approximately 100-200 pS (10-20 pS pF-1), similar to previous estimates in mouse β-cells. We then investigate the role of gap junction coupling in synchronizing and modifying other forms of electrical activity in human β-cell clusters. We find that electrical coupling can prolong the period of rapid bursting electrical activity, and synchronize metabolically driven slow bursting, in particular when the metabolic oscillators are in phase. Our results show that realistic coupling conductances are sufficient to promote synchrony in small clusters of human β-cells as observed experimentally, and provide motivation for further detailed studies of electrical coupling in human pancreatic islets.

  16. Excitonic Coupling and Femtosecond Relaxation of Zinc Porphyrin Oligomers Linked with Triazole Bridge: Dynamics and Modeling.

    PubMed

    Bukreev, Alexey; Mikhailov, Konstantin; Shelaev, Ivan; Gostev, Fedor; Polevaya, Yuliya; Tyurin, Vladimir; Beletskaya, Irina; Umansky, Stanislav; Nadtochenko, Victor

    2016-03-31

    The synthesis of new zinc porphyrin oligomers linked by a triazole bridge was carried out via "click" reaction. A split in the porphyrin oligomer B-band was observed. It was considered as evidence of exciton-excitonic coupling. The relaxation of excited states in Q-band porphyrin oligomers was studied by the femtosecond laser spectroscopy technique with a 20 fs pump pulse. The transient oscillations of two B-band excitonic peaks have a π-radian shift. For explanation of the coherent oscillation, a theoretical model was developed. The model considered the combination of the exciton-excitonic coupling between porphyrin rings in dimer and weak exciton-vibronic coupling in one porphyrin ring. By varying the values of the structural parameters of porphyrins (the strength values of this couplings and measure of symmetry breaking), we obtained correspondence between the experimental data (phase shift and amplitudes of the spectrum oscillations) and the predictions of the model developed here. PMID:26935579

  17. An equilibrium model for the coupled ocean-atmosphere boundary layer in the tropics

    NASA Technical Reports Server (NTRS)

    Sui, C.-H.; Lau, K.-M.; Betts, Alan K.

    1991-01-01

    An atmospheric convective boundary layer (CBL) model is coupled to an ocean mixed-layer (OML) model in order to study the equilibrium state of the coupled system in the tropics, particularly in the Pacific region. The equilibrium state of the coupled system is solved as a function of sea-surface temperature (SST) for a given surface wind and as a function of surface wind for a given SST. It is noted that in both cases, the depth of the CBL and OML increases and the upwelling below the OML decreases, corresponding to either increasing SST or increasing surface wind. The coupled ocean-atmosphere model is solved iteratively as a function of surface wind for a fixed upwelling and a fixed OML depth, and it is observed that SST falls with increasing wind in both cases. Realistic gradients of mixed-layer depth and upwelling are observed in experiments with surface wind and SST prescribed as a function of longitude.

  18. Neutron and ARPES constraints on the couplings of the multiorbital Hubbard model for the iron pnictides

    SciTech Connect

    Luo, Qinlong; Martins, G. B.; Daghofer, M.; Yu, Rong; Yildirim, Yucel; Moreo, Adriana; Dagotto, Elbio R

    2010-01-01

    The results of neutron-scattering and angle-resolved photoemission experiments for the Fe-pnictide parent compounds, and their metallic nature, are shown to impose severe constraints on the range of values that can be considered realistic for the intraorbital Hubbard repulsion U and Hund coupling J in multiorbital Hubbard models treated in the mean-field approximation. Phase diagrams for three- and five-orbital models are here provided, and the physically realistic regime of couplings is highlighted, to guide future theoretical work into the proper region of parameters of Hubbard models. In addition, using the random phase approximation, the pairing tendencies in these realistic coupling regions are investigated. It is shown that the dominant spin-singlet pairing channels in these coupling regimes correspond to nodal superconductivity, with strong competition between several states that belong to different irreducible representations. This is compatible with experimental bulk measurements that have reported the existence of nodes in several Fe-pnictide compounds.

  19. Emergent Central Pattern Generator Behavior in Gap-Junction-Coupled Hodgkin-Huxley Style Neuron Model

    PubMed Central

    Memelli, Heraldo; Solomon, Irene C.

    2012-01-01

    Most models of central pattern generators (CPGs) involve two distinct nuclei mutually inhibiting one another via synapses. Here, we present a single-nucleus model of biologically realistic Hodgkin-Huxley neurons with random gap junction coupling. Despite no explicit division of neurons into two groups, we observe a spontaneous division of neurons into two distinct firing groups. In addition, we also demonstrate this phenomenon in a simplified version of the model, highlighting the importance of afterhyperpolarization currents (IAHP) to CPGs utilizing gap junction coupling. The properties of these CPGs also appear sensitive to gap junction conductance, probability of gap junction coupling between cells, topology of gap junction coupling, and, to a lesser extent, input current into our simulated nucleus. PMID:23365558

  20. Decadal variability in historical simulations by coupled climate models in CMIP5

    NASA Astrophysics Data System (ADS)

    Yoon, J.; Rasch, P. J.

    2013-12-01

    Climate variability beyond interannual time scales has not been well explored by coupled climate models because of relatively poor simulations and shorter observational record to verify its robustness. However, a newly available historical data assimilation products such as 20CR, newly compiled surface observation datasets such as CRU_TS3.2 and GPCC, paleoclimate records, and improved simulation by coupled climate models provide a new opportunity. In this study, we'll evaluate how well fully coupled climate models in CMIP5 simulate a couple of well known decadal/multi-decadal climate variabilities, such as Pacific Decadal Variability (PDV), Atlantic Multi-decadal oscillation (AMO), and decadal component of North Atlantic Oscillation (NAO). Further, we'll use sets of sensitivity experiments with CESM1 to investigate the anthropogenic causes of these decadal variabilities.

  1. Northern Forest Ecosystem Dynamics Using Coupled Models and Remote Sensing

    NASA Technical Reports Server (NTRS)

    Ranson, K. J.; Sun, G.; Knox, R. G.; Levine, E. R.; Weishampel, J. F.; Fifer, S. T.

    1999-01-01

    Forest ecosystem dynamics modeling, remote sensing data analysis, and a geographical information system (GIS) were used together to determine the possible growth and development of a northern forest in Maine, USA. Field measurements and airborne synthetic aperture radar (SAR) data were used to produce maps of forest cover type and above ground biomass. These forest attribute maps, along with a conventional soils map, were used to identify the initial conditions for forest ecosystem model simulations. Using this information along with ecosystem model results enabled the development of predictive maps of forest development. The results obtained were consistent with observed forest conditions and expected successional trajectories. The study demonstrated that ecosystem models might be used in a spatial context when parameterized and used with georeferenced data sets.

  2. Charge-coupled-device X-ray detector performance model

    NASA Technical Reports Server (NTRS)

    Bautz, M. W.; Berman, G. E.; Doty, J. P.; Ricker, G. R.

    1987-01-01

    A model that predicts the performance characteristics of CCD detectors being developed for use in X-ray imaging is presented. The model accounts for the interactions of both X-rays and charged particles with the CCD and simulates the transport and loss of charge in the detector. Predicted performance parameters include detective and net quantum efficiencies, split-event probability, and a parameter characterizing the effective thickness presented by the detector to cosmic-ray protons. The predicted performance of two CCDs of different epitaxial layer thicknesses is compared. The model predicts that in each device incomplete recovery of the charge liberated by a photon of energy between 0.1 and 10 keV is very likely to be accompanied by charge splitting between adjacent pixels. The implications of the model predictions for CCD data processing algorithms are briefly discussed.

  3. Coupled THCM Modeling of Gas Hydrate Bearing Sediments

    NASA Astrophysics Data System (ADS)

    Sanchez, M. J.; Gai, X., Sr.; Shastri, A.; Santamarina, J. C.

    2014-12-01

    Gas hydrates are crystalline clathrate compounds made of water and a low molecular gas, like methane. Gas hydrates are generally present in oil-producing areas and in permafrost regions. Methane hydrate deposits can lead to large-scale submarine slope failures, blowouts, platform foundation failures, and borehole instability. Gas hydrates constitute also an attractive source of energy as they are estimated to contain very large reserves of methane. Hydrate formation, dissociation and methane production from hydrate bearing sediments are coupled Thermo-Hydro-Mechanical (THM) processes that involve, amongst other, exothermic formation and endothermic dissociation of hydrate and ice phases, mixed fluid flow and large changes in fluid pressure. A comprehensive THM formulation is briefly presented here. Momentum balance, mass balance and energy balance equations take into consideration the interaction among all phases (i.e. solid, liquid, gas, hydrates and ice) and mechanical equilibrium. Constitutive equations describe the intrinsic THM behavior of the sediment. Simulation results conducted for hydrate bearing sediments subjected to boundary conditions highlight the complex interaction among THM processes in hydrate bearing sediments.

  4. Advancing coupled human-earth system models: The integrated Earth System Model Project

    NASA Astrophysics Data System (ADS)

    Thomson, A. M.; Edmonds, J. A.; Collins, W.; Thornton, P. E.; Hurtt, G. C.; Janetos, A. C.; Jones, A.; Mao, J.; Chini, L. P.; Calvin, K. V.; Bond-Lamberty, B. P.; Shi, X.

    2012-12-01

    As human and biogeophysical models develop, opportunities for connections between them evolve and can be used to advance our understanding of human-earth systems interaction in the context of a changing climate. One such integration is taking place with the Community Earth System Model (CESM) and the Global Change Assessment Model (GCAM). A multi-disciplinary, multi-institution team has succeeded in integrating the GCAM integrated assessment model of human activity into CESM to dynamically represent the feedbacks between changing climate and human decision making, in the context of greenhouse gas mitigation policies. The first applications of this capability have focused on the feedbacks between climate change impacts on terrestrial ecosystem productivity and human decisions affecting future land use change, which are in turn connected to human decisions about energy systems and bioenergy production. These experiments have been conducted in the context of the RCP4.5 scenario, one of four pathways of future radiative forcing being used in CMIP5, which constrains future human-induced greenhouse gas emissions from energy and land activities to stabilize radiative forcing at 4.5 W/m2 (~650 ppm CO2 -eq) by 2100. When this pathway is run in GCAM with the climate feedback on terrestrial productivity from CESM, there are implications for both the land use and energy system changes required for stabilization. Early findings indicate that traditional definitions of radiative forcing used in scenario development are missing a critical component of the biogeophysical consequences of land use change and their contribution to effective radiative forcing. Initial full coupling of the two global models has important implications for how climate impacts on terrestrial ecosystems changes the dynamics of future land use change for agriculture and forestry, particularly in the context of a climate mitigation policy designed to reduce emissions from land use as well as energy systems

  5. Strong coupling and quasispinor representations of the SU(3) rotor model

    NASA Astrophysics Data System (ADS)

    Rowe, D. J.; de Guise, H.

    1992-06-01

    We define a coupling scheme, in close parallel to the coupling scheme of Elliott and Wilsdon, in which nucleonic intrinsic spins are strongly coupled to SU(3) spatial wave functions. The scheme is proposed for shell-model calculations in strongly deformed nuclei and for semimicroscopic analyses of rotations in odd-mass nuclei and other nuclei for which the spin-orbit interaction is believed to play an important role. The coupling scheme extends the domain of utility of the SU(3) model, and the symplectic model, to heavy nuclei and odd-mass nuclei. It is based on the observation that the low angular-momentum states of an SU(3) irrep have properties that mimic those of a corresponding irrep of the rotor algebra. Thus, we show that strongly coupled spin-SU(3) bands behave like strongly coupled rotor bands with properties that approach those of irreducible representations of the rigid-rotor algebra in the limit of large SU(3) quantum numbers. Moreover, we determine that the low angular-momentum states of a strongly coupled band of states of half-odd integer angular momentum behave to a high degree of accuracy as if they belonged to an SU(3) irrep. These are the quasispinor SU(3) irreps referred to in the title.

  6. Exact Mass-Coupling Relation for the Homogeneous Sine-Gordon Model

    NASA Astrophysics Data System (ADS)

    Bajnok, Zoltán; Balog, János; Ito, Katsushi; Satoh, Yuji; Tóth, Gábor Zsolt

    2016-05-01

    We derive the exact mass-coupling relation of the simplest multiscale quantum integrable model, i.e., the homogeneous sine-Gordon model with two mass scales. The relation is obtained by comparing the perturbed conformal field theory description of the model valid at short distances to the large distance bootstrap description based on the model's integrability. In particular, we find a differential equation for the relation by constructing conserved tensor currents, which satisfy a generalization of the Θ sum rule Ward identity. The mass-coupling relation is written in terms of hypergeometric functions.

  7. Exact Mass-Coupling Relation for the Homogeneous Sine-Gordon Model.

    PubMed

    Bajnok, Zoltán; Balog, János; Ito, Katsushi; Satoh, Yuji; Tóth, Gábor Zsolt

    2016-05-01

    We derive the exact mass-coupling relation of the simplest multiscale quantum integrable model, i.e., the homogeneous sine-Gordon model with two mass scales. The relation is obtained by comparing the perturbed conformal field theory description of the model valid at short distances to the large distance bootstrap description based on the model's integrability. In particular, we find a differential equation for the relation by constructing conserved tensor currents, which satisfy a generalization of the Θ sum rule Ward identity. The mass-coupling relation is written in terms of hypergeometric functions. PMID:27203313

  8. 5th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention: summary of key research and implications for policy and practice - operations research.

    PubMed

    Kort, Rodney

    2010-01-01

    Operations research was added as a fourth scientific track to the pathogenesis conference series at the 5th IAS Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2009) in recognition of the importance of this growing research field and the need for applied research to inform and evaluate the scale up of some key interventions in HIV treatment, care and prevention.Several studies demonstrated how task shifting and the decentralization of health services can leverage scarce health care resources to support scale-up efforts. For example, a Ugandan study comparing home-based and facility-based antiretroviral therapy (ART) delivery found that both delivered equivalent clinical outcomes, but home-based delivery resulted in substantial cost savings to patients; and a retrospective cohort analysis of an HIV care programme in Lesotho demonstrated that devolving routine patient management to nurses and trained counsellors resulted in impressive gains in annual enrolment, retention in care and other clinical indicators.Studies also demonstrated how the use of trained counsellors and public health advisors could effectively expand both clinical and public health capacity in low-income settings. Studies evaluating the impact of integrating HIV and TB care resulted in improved treatment outcomes in coinfected populations, the development of environmental interventions to reduce TB transmission, and uncovering of the extent of multi-drug-resistant and extremely drug-resistant tuberculosis (MDR-TB and XDR-TB) in KwaZulu-Natal, South Africa.Some mathematical modelling and cost-effectiveness studies presented at this meeting addressed interventions to increase retention in care, and strengthened the evidentiary basis for universal voluntary testing and immediate ART on reducing HIV transmission; debate continued about the relative merits of clinical versus laboratory monitoring. Finally, a provocative plenary presentation outlined the shortfalls of current prevention

  9. Relationship between Long Working Hours and Suicidal Thoughts: Nationwide Data from the 4th and 5th Korean National Health and Nutrition Examination Survey

    PubMed Central

    Yoon, Jin-Ha; Jung, Pil Kyun; Roh, Jaehoon; Seok, Hongdeok; Won, Jong-Uk

    2015-01-01

    Background Long working hours are a worldwide problem and may increase the risk of various health issues. However, the health effects of long working hours on suicidal thoughts have not been frequently studied. Our goal was to investigate the relationship between long working hours and suicidal thoughts in the rapidly developing country of Korea. Methods Data from 12,076 participants (7,164 men, 4,912 women) from the 4th and 5th Korean National Health and Nutrition Examination Surveys were used for the current analysis. Multivariate logistic regression models were used to estimate odds ratios and 95% confidence intervals for suicidal thoughts. Combined effects of long working hours and lower socioeconomic status or sleep disturbance were also estimated. Results Compared to groups who worked less than 52 hours per week, odds ratios (95% confidence intervals) for suicidal thoughts in groups who worked 60 hours or more per week were 1.36 (1.09–1.70) for males and 1.38 (1.11–1.72) for females, even after controlling for household income, marital status, history of hypertension or diabetes mellitus, health-related behaviors, and past two weeks’ experience of injury, intoxication, or acute or chronic diseases, as well as type of work. The combined effects of long working hours with lower socioeconomic status, or with sleep disturbance, were also significantly higher compared to participants who worked less than 52 hours per week with higher socioeconomic status, or with 6–8 hours of nighttime sleep. Conclusion In this study, long working hours were linked to suicidal thoughts for both genders. Additionally, the odds of those suicidal thoughts were higher for lower socioeconomic groups. To prevent adverse psychological health problems such as suicidal thoughts, a strategy regarding long working hours should be investigated. PMID:26080022

  10. Models for electromagnetic coupling of lightning onto multiconductor cables in underground cavities

    NASA Astrophysics Data System (ADS)

    Higgins, Matthew Benjamin

    This dissertation documents the measurements, analytical modeling, and numerical modeling of electromagnetic transfer functions to quantify the ability of cloud-to-ground lightning strokes (including horizontal arc-channel components) to couple electromagnetic energy onto multiconductor cables in an underground cavity. Measurements were performed at the Sago coal mine located near Buckhannon, WV. These transfer functions, coupled with mathematical representations of lightning strokes, are then used to predict electric fields within the mine and induced voltages on a cable that was left abandoned in the sealed area of the Sago mine. If voltages reached high enough levels, electrical arcing could have occurred from the abandoned cable. Electrical arcing is known to be an effective ignition source for explosive gas mixtures. Two coupling mechanisms were measured: direct and indirect drive. Direct coupling results from the injection or induction of lightning current onto metallic conductors such as the conveyors, rails, trolley communications cable, and AC power shields that connect from the outside of the mine to locations deep within the mine. Indirect coupling results from electromagnetic field propagation through the earth as a result of a cloud-to-ground lightning stroke or a long, low-altitude horizontal current channel from a cloud-to-ground stroke. Unlike direct coupling, indirect coupling does not require metallic conductors in a continuous path from the surface to areas internal to the mine. Results from the indirect coupling measurements and analysis are of great concern. The field measurements, modeling, and analysis indicate that significant energy can be coupled directly into the sealed area of the mine. Due to the relatively low frequency content of lightning (< 100 kHz), electromagnetic energy can readily propagate through hundreds of feet of earth. Indirect transfer function measurements compare extremely well with analytical and computational models

  11. Integration of physical activity and technology motion devices within a combined 5th and 6th grade science curriculum

    NASA Astrophysics Data System (ADS)

    Finn, Kevin Eugene

    Background: National recommendations to increase school-based physical activity and promote academic success advise incorporating movement into traditional classroom lessons. Classroom-based physical activities have favorable associations with indicators of cognitive functioning, academic behaviors, and academic achievement. Purpose: This study analyzed the Active Science framework, which incorporated school-based physical activity within interactive science classroom lessons. Specifically, the study measured the effects of the Active Science framework on student physical activity levels in the classroom, student learning of science inquiry skills and content knowledge, and student perceptions of physical activity and science. A secondary purpose was to evaluate the teachers' perceptions on the implementation of the framework. Subjects: Participants were 37 Hispanic girls (age=11.1 +/-0.8 yr) in mixed 5th/6th grade science classes in a private, urban middle school. Methods: Physical activity levels of the students during the Active Science framework were measured using pedometers and heart rate monitors. Pre- and post-tests were used to assess the levels of learning achieved by the students in science inquiry skills and content during the Active Science framework. Student perceptions and attitudes toward science and physical activity were measured during student focus groups and pre-post perception surveys. Lesson plan evaluations completed by the teachers and structured interviews provided data on implementation of the framework. Results: Physical activity results showed heart rate (146 +/-9 bpm); maximal heart rate (196 +/-10.6 bpm); time (35 +/-2.5 mins); steps (3050 +/-402.7); calories (99 +/-8.4 kcal); and distance (1.1 +/-0.2 miles) while performing the activity portion of the science lessons were consistent with national recommendations for accumulating school-based physical activity. Significant increases in science content and skills test scores with a 22

  12. 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors.

    PubMed

    Pandit, J J; Andrade, J; Bogod, D G; Hitchman, J M; Jonker, W R; Lucas, N; Mackay, J H; Nimmo, A F; O'Connor, K; O'Sullivan, E P; Paul, R G; Palmer, J H M G; Plaat, F; Radcliffe, J J; Sury, M R J; Torevell, H E; Wang, M; Hainsworth, J; Cook, T M

    2014-10-01

    We present the main findings of the 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia (AAGA). Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ~1:19,600 anaesthetics (95% confidence interval 1:16,700-23,450). However, there was considerable variation across subtypes of techniques or subspecialities. The incidence with neuromuscular block (NMB) was ~1:8200 (1:7030-9700), and without, it was ~1:135,900 (1:78,600-299,000). The cases of AAGA reported to NAP5 were overwhelmingly cases of unintended awareness during NMB. The incidence of accidental awareness during Caesarean section was ~1:670 (1:380-1300). Two-thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental, rapid sequence induction, obesity, difficult airway management, NMB, and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One-third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, mostly due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex, age (younger adults, but not children), obesity, anaesthetist seniority (junior trainees), previous awareness, out-of-hours operating, emergencies, type of surgery (obstetric, cardiac, thoracic), and use of NMB. The following factors were not risk factors for accidental awareness: ASA physical status, race, and use or omission

  13. Effect on Physical Activity of a Randomized Afterschool Intervention for Inner City Children in 3rd to 5th Grade

    PubMed Central

    Crouter, Scott E.; de Ferranti, Sarah D.; Whiteley, Jessica; Steltz, Sarah K.; Osganian, Stavroula K.; Feldman, Henry A.; Hayman, Laura L.

    2015-01-01

    Background Less than 45% of U.S. children meet the 60 min.d-1 physical activity (PA) guideline. Structured after-school PA programing is one approach to help increase activity levels. This study aimed to evaluate the feasibility and short-term impact of a supervised after-school PA and nutrition education program on activity levels. Methods Forty-two 3rd-5th graders from an inner-city school in Boston, MA were randomly assigned to a 10-wk after-school program of either: 1) weekly nutrition education, or 2) weekly nutrition education plus supervised PA 3 d.wk-1 at a community-based center. At baseline and follow-up, PA was measured using accelerometry and fitness (VO2max) was estimated using the PACER 15-m shuttle run. Additional measures obtained were non-fasting finger stick total cholesterol (TC) and glucose levels, waist circumference (WC), body mass index (BMI), percent body fat (%BF), and blood pressure (BP). Values are presented as mean±SE, unless noted otherwise. Results Thirty-six participants completed the study (mean±SD; age 9.7±0.9 years). Participants attended >80% of the sessions. After adjusting for accelerometer wear time and other design factors, light and moderate-to-vigorous PA (MVPA) increased in the nutrition+PA group (+21.5±14.5 and +8.6±8.0 min.d-1, respectively) and decreased in the nutrition only group (-35.2±16.3 and -16.0±9.0 min.d-1, respectively); mean difference between groups of 56.8±21.7 min.d-1 (light PA, p = 0.01) and 24.5±12.0 min.d-1 (MVPA, p = 0.04). Time spent in sedentary behaviors declined in the nutrition+PA group (-14.8±20.7 min.d-1) and increased in the nutrition only group (+55.4±23.2 min.d-1); mean difference between groups of -70.2±30.9 min.d-1 (p = 0.02). Neither group showed changes in TC, BP, WC, %BF, BMI percentile, or fitness (p>0.05). Conclusions The supervised afterschool community-based nutrition and PA program was well accepted and had high attendance. The changes in light PA and MVPA has potential

  14. PREFACE: PASREG 2005: The 5th International Workshop on Processing and Applications of Superconducting (RE)BCO Large Grain Materials

    NASA Astrophysics Data System (ADS)

    Murakami, Masato; Cardwell, David; Salama, Kamel; Izumi, Mitsuru

    2006-07-01

    Large grain, (RE)BCO bulk superconductors fabricated by top-seeded melt growth (TSMG) have outstanding potential for a variety of engineering applications such as magnetic separators, flywheel energy storage, magnetic bearings and permanent magnet-like devices due to their ability to generate large magnetic fields. Recent developments in materials and systems research has led to the manufacture of proto-type devices for use in magnetron sputtering, magnetic stirrers and a mobile magnetic separator based on bulk materials technology. This issue contains selected papers presented at the 5th International Workshop on the Processing and Applications of Superconducting (RE)BCO Large Grain Materials held on 21-23 October 2005 at Tokyo Marine University to report progress made in this field over the previous two years. The workshop followed those held previously in Cambridge, UK (1997), Morioka, Japan (1999), Seattle, USA (2001), and Jena, Germany (2003). A total of 76 papers were presented at this workshop, of which 27 were presented in oral form and 49 were presented as posters. This issue contains a total of 36 selected papers in the following categories of bulk (RE)BCO large grain material: processing, characterization, and applications. The editors are grateful for the support of many colleagues both within and outside the immediate bulk community who reviewed the manuscripts to guarantee their high technical quality. Finally, the attendees wish to acknowledge the efforts of Professor Mitsuru Izumi and his research staff from Tokyo Marine University for being generous hosts during the workshop, and the efforts of Professor Masato Murakami for the overall organization of the meeting. The International PASREG Board selected the following distinguished researchers as recipients of the 2005 PASREG Award of Excellence to acknowledge their contribution to the development of bulk high temperature superconductors: • Dr Michael Strasik (Boeing, Seattle, USA) • Dr Hiroshi

  15. Two Successful Outreach Programs at Storm Peak Laboratory: GRASP for Undergraduates and Partnership for 5th Grade Science Education

    NASA Astrophysics Data System (ADS)

    Hallar, A. G.; McCubbin, I. B.; Wright, J.

    2007-12-01

    The Desert Research Institute operates a high elevation facility, Storm Peak Laboratory (SPL), located on the Steamboat Springs Ski Resort at an elevation 10,500 ft. SPL provides an ideal location for long-term atmospheric research. The SPL mission statement is to ensure that the laboratory will continue to integrate climate research and education by advancing discovery and understanding within the field of pollution, aerosol and cloud interactions. During the last year, SPL has created two successful outreach programs reaching very different audiences. First, to engage students from local elementary schools, SPL established a 5th grade climate education program. This program is based on a partnership between SPL and Yampatika's&penvironmental educators. Yampatika is a non-profit outdoor environmental education organization. The program spans three days for each school and includes five elementary schools. During the first day, educators from Yampatika visit each classroom to introduce the concepts of climate and weather as well as teach students how to use scientific equipment. During the field program on the second day, students measure and record information about temperature, pressure, relative humidity, wind speed, and particle concentration while they travel to SPL via the gondola (in winter) or Suburban (in fall). Once at the laboratory, students tour the facility, discuss SPL research activities, and explore application of these activities to their curriculum. Following the field trip, Yampatika educators and SPL scientists will visit the school for a follow-up to help children explore concepts, answer questions, and evaluate students" learning. The second program, Geoscience Research at Storm Peak (GRASP), was designed to engage students from underrepresented groups and created a partnership between three Minority Serving Institutions and the University of Nevada, Reno (UNR). Undergraduate students from Tennessee State University, Howard University

  16. A Coupled Probabilistic Wake Vortex and Aircraft Response Prediction Model

    NASA Technical Reports Server (NTRS)

    Gloudemans, Thijs; Van Lochem, Sander; Ras, Eelco; Malissa, Joel; Ahmad, Nashat N.; Lewis, Timothy A.

    2016-01-01

    Wake vortex spacing standards along with weather and runway occupancy time, restrict terminal area throughput and impose major constraints on the overall capacity and efficiency of the National Airspace System (NAS). For more than two decades, the National Aeronautics and Space Administration (NASA) has been conducting research on characterizing wake vortex behavior in order to develop fast-time wake transport and decay prediction models. It is expected that the models can be used in the systems level design of advanced air traffic management (ATM) concepts that safely increase the capacity of the NAS. It is also envisioned that at a later stage of maturity, these models could potentially be used operationally, in groundbased spacing and scheduling systems as well as on the flight deck.

  17. Modeling of Magnetoelastic Nanostructures with a Fully-coupled Mechanical-Micromagnetic Model and Its Applications

    NASA Astrophysics Data System (ADS)

    Liang, Cheng-Yen

    Micromagnetic simulations of magnetoelastic nanostructures traditionally rely on either the Stoner-Wohlfarth model or the Landau-Lifshitz-Gilbert (LLG) model assuming uniform strain (and/or assuming uniform magnetization). While the uniform strain assumption is reasonable when modeling magnetoelastic thin films, this constant strain approach becomes increasingly inaccurate for smaller in-plane nanoscale structures. In this dissertation, a fully-coupled finite element micromagnetic method is developed. The method deals with the micromagnetics, elastodynamics, and piezoelectric effects. The dynamics of magnetization, non-uniform strain distribution, and electric fields are iteratively solved. This more sophisticated modeling technique is critical for guiding the design process of the nanoscale strain-mediated multiferroic elements such as those needed in multiferroic systems. In this dissertation, we will study magnetic property changes (e.g., hysteresis, coercive field, and spin states) due to strain effects in nanostructures. in addition, a multiferroic memory device is studied. The electric-field-driven magnetization switching by applying voltage on patterned electrodes simulation in a nickel memory device is shown in this work. The deterministic control law for the magnetization switching in a nanoring with electric field applied to the patterned electrodes is investigated. Using the patterned electrodes, we show that strain-induced anisotropy is able to be controlled, which changes the magnetization deterministically in a nano-ring.

  18. Evaluating the Carbon Cycle of a Coupled Atmosphere-Biosphere Model

    SciTech Connect

    Delire, C; Foley, J A; Thompson, S

    2002-08-21

    We investigate how well a coupled biosphere-atmosphere model, CCM3-IBIS, can simulate the functioning of the terrestrial biosphere and the carbon cycling through it. The simulated climate is compared to observations, while the vegetation cover and the carbon cycle are compared to an offline version of the biosphere model IBIS forced with observed climatic variables. The simulated climate presents some local biases that strongly affect the vegetation (e.g., a misrepresentation of the African monsoon). Compared to the offline model, the coupled model simulates well the globally averaged carbon fluxes and vegetation pools. The zonal mean carbon fluxes and the zonal mean seasonal cycle are also well represented except between 0{sup o} and 20{sup o}N due to the misrepresentation of the African monsoon. These results suggest that, despite regional biases in climate and ecosystem simulations, this coupled atmosphere-biosphere model can be used to explore geographic and temporal variations in the global carbon cycle.

  19. Modeling of the coupled magnetospheric and neutral wind dynamos

    NASA Technical Reports Server (NTRS)

    Thayer, J. P.; Vickrey, J. F.; Heelis, R. A.; Gary, J. B.

    1995-01-01

    Work at SRI involved modeling the exchange of electromagnetic energy between the ionosphere and magnetosphere to help interpret the DE-B Poynting flux observations. To describe the electrical properties of the high-latitude ionosphere, we constructed a numerical model, from the framework provided by the Vector Spherical Harmonic (VSH) model, that determines the ionospheric currents, conductivities, and electric fields including both magnetospheric inputs and neutral wind dynamo effects. This model development grew from the earlier question of whether an electrical energy source in the ionosphere was capable of providing an upward Poynting flux. The model solves the steady-state neutral wind dynamo equations and the Poynting flux equation to provide insight into the electrodynamic role of the neutral winds. The modeling effort to determine the high-latitude energy flux has been able to reproduce many of the large-scale features observed in the Poynting flux measurements made by DE-2. Because the Poynting flux measurement is an integrated result of energy flux into or out of the ionosphere, we investigated the ionospheric properties that may contribute to the observed flux of energy measured by the spacecraft. During steady state the electromagnetic energy flux, or DC Poynting flux, is equal to the Joule heating rate and the mechanical energy transfer rate in the high-latitude ionosphere. Although the Joule heating rate acts as an energy sink, transforming electromagnetic energy into thermal or internal energy of the gas, the mechanical energy transfer rate may be either a sink or source of electromagnetic energy. In the steady state, it is only the mechanical energy transfer rate that can generate electromagnetic energy and result in a DC Poynating flux that is directed out of the ionosphere.

  20. Recent Advances in Modeling of the Atmospheric Boundary Layer and Land Surface in the Coupled WRF-CMAQ Model

    EPA Science Inventory

    Advances in the land surface model (LSM) and planetary boundary layer (PBL) components of the WRF-CMAQ coupled meteorology and air quality modeling system are described. The aim of these modifications was primarily to improve the modeling of ground level concentrations of trace c...